mirror of
https://git.busybox.net/busybox.git
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2484 lines
87 KiB
C
2484 lines
87 KiB
C
/*
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* Copyright (C) 2017 Denys Vlasenko
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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//config:config TLS
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//config: bool #No description makes it a hidden option
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//config: default n
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//Note:
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//Config.src also defines FEATURE_TLS_SHA1 option
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//kbuild:lib-$(CONFIG_TLS) += tls.o
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//kbuild:lib-$(CONFIG_TLS) += tls_pstm.o
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//kbuild:lib-$(CONFIG_TLS) += tls_pstm_montgomery_reduce.o
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//kbuild:lib-$(CONFIG_TLS) += tls_pstm_mul_comba.o
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//kbuild:lib-$(CONFIG_TLS) += tls_pstm_sqr_comba.o
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//kbuild:lib-$(CONFIG_TLS) += tls_aes.o
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//kbuild:lib-$(CONFIG_TLS) += tls_aesgcm.o
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//kbuild:lib-$(CONFIG_TLS) += tls_rsa.o
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//kbuild:lib-$(CONFIG_TLS) += tls_fe.o
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//kbuild:lib-$(CONFIG_TLS) += tls_sp_c32.o
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#include "tls.h"
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// Usually enabled. You can disable some of them to force only
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// specific ciphers to be advertized to server.
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// (this would not exclude code to handle disabled ciphers, no code size win)
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#define ALLOW_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 1
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#define ALLOW_ECDHE_RSA_WITH_AES_128_CBC_SHA256 1
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#define ALLOW_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 1
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#define ALLOW_ECDHE_RSA_WITH_AES_128_GCM_SHA256 1
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#define ALLOW_RSA_WITH_AES_128_CBC_SHA256 1
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#define ALLOW_RSA_WITH_AES_256_CBC_SHA256 1
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#define ALLOW_RSA_WITH_AES_128_GCM_SHA256 1
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#define ALLOW_CURVE_P256 1
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#define ALLOW_CURVE_X25519 1
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// For testing (does everything except encrypting).
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// works against "openssl s_server -cipher NULL"
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// and against wolfssl-3.9.10-stable/examples/server/server.c:
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#define ALLOW_RSA_NULL_SHA256 0
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#define TLS_DEBUG 0
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#define TLS_DEBUG_HASH 0
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#define TLS_DEBUG_DER 0
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#define TLS_DEBUG_FIXED_SECRETS 0
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#if 0
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# define dump_raw_out(...) dump_hex(__VA_ARGS__)
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#else
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# define dump_raw_out(...) ((void)0)
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#endif
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#if 0
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# define dump_raw_in(...) dump_hex(__VA_ARGS__)
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#else
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# define dump_raw_in(...) ((void)0)
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#endif
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#if TLS_DEBUG
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# define dbg(...) fprintf(stderr, __VA_ARGS__)
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#else
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# define dbg(...) ((void)0)
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#endif
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#if TLS_DEBUG_DER
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# define dbg_der(...) fprintf(stderr, __VA_ARGS__)
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#else
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# define dbg_der(...) ((void)0)
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#endif
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//TLS 1.2
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#define TLS_MAJ 3
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#define TLS_MIN 3
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#define RECORD_TYPE_CHANGE_CIPHER_SPEC 20 /* 0x14 */
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#define RECORD_TYPE_ALERT 21 /* 0x15 */
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#define RECORD_TYPE_HANDSHAKE 22 /* 0x16 */
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#define RECORD_TYPE_APPLICATION_DATA 23 /* 0x17 */
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#define HANDSHAKE_HELLO_REQUEST 0 /* 0x00 */
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#define HANDSHAKE_CLIENT_HELLO 1 /* 0x01 */
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#define HANDSHAKE_SERVER_HELLO 2 /* 0x02 */
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#define HANDSHAKE_HELLO_VERIFY_REQUEST 3 /* 0x03 */
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#define HANDSHAKE_NEW_SESSION_TICKET 4 /* 0x04 */
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#define HANDSHAKE_CERTIFICATE 11 /* 0x0b */
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#define HANDSHAKE_SERVER_KEY_EXCHANGE 12 /* 0x0c */
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#define HANDSHAKE_CERTIFICATE_REQUEST 13 /* 0x0d */
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#define HANDSHAKE_SERVER_HELLO_DONE 14 /* 0x0e */
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#define HANDSHAKE_CERTIFICATE_VERIFY 15 /* 0x0f */
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#define HANDSHAKE_CLIENT_KEY_EXCHANGE 16 /* 0x10 */
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#define HANDSHAKE_FINISHED 20 /* 0x14 */
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#define TLS_EMPTY_RENEGOTIATION_INFO_SCSV 0x00FF /* not a real cipher id... */
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#define SSL_NULL_WITH_NULL_NULL 0x0000
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#define SSL_RSA_WITH_NULL_MD5 0x0001
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#define SSL_RSA_WITH_NULL_SHA 0x0002
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#define SSL_RSA_WITH_RC4_128_MD5 0x0004
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#define SSL_RSA_WITH_RC4_128_SHA 0x0005
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#define TLS_RSA_WITH_IDEA_CBC_SHA 0x0007 /* 7 */
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#define SSL_RSA_WITH_3DES_EDE_CBC_SHA 0x000A /* 10 */
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#define SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA 0x0016 /* 22 */
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#define SSL_DH_anon_WITH_RC4_128_MD5 0x0018 /* 24 */
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#define SSL_DH_anon_WITH_3DES_EDE_CBC_SHA 0x001B /* 27 */
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#define TLS_RSA_WITH_AES_128_CBC_SHA 0x002F /*SSLv3 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA1 */
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#define TLS_DHE_RSA_WITH_AES_128_CBC_SHA 0x0033 /* 51 */
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#define TLS_DH_anon_WITH_AES_128_CBC_SHA 0x0034 /* 52 */
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#define TLS_RSA_WITH_AES_256_CBC_SHA 0x0035 /* 53 */
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#define TLS_DHE_RSA_WITH_AES_256_CBC_SHA 0x0039 /* 57 */
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#define TLS_DH_anon_WITH_AES_256_CBC_SHA 0x003A /* 58 */
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#define TLS_RSA_WITH_NULL_SHA256 0x003B /* 59 */
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#define TLS_RSA_WITH_AES_128_CBC_SHA256 0x003C /* 60 */
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#define TLS_RSA_WITH_AES_256_CBC_SHA256 0x003D /* 61 */
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#define TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 0x0067 /* 103 */
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#define TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 0x006B /* 107 */
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#define TLS_PSK_WITH_AES_128_CBC_SHA 0x008C /* 140 */
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#define TLS_PSK_WITH_AES_256_CBC_SHA 0x008D /* 141 */
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#define TLS_DHE_PSK_WITH_AES_128_CBC_SHA 0x0090 /* 144 */
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#define TLS_DHE_PSK_WITH_AES_256_CBC_SHA 0x0091 /* 145 */
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#define TLS_RSA_WITH_SEED_CBC_SHA 0x0096 /* 150 */
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#define TLS_RSA_WITH_AES_128_GCM_SHA256 0x009C /*TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(128) Mac=AEAD */
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#define TLS_RSA_WITH_AES_256_GCM_SHA384 0x009D /*TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(256) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 0x009E /*TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(128) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 0x009F /*TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(256) Mac=AEAD */
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#define TLS_DH_anon_WITH_AES_128_GCM_SHA256 0x00A6 /* RFC 5288 */
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#define TLS_DH_anon_WITH_AES_256_GCM_SHA384 0x00A7 /* RFC 5288 */
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#define TLS_PSK_WITH_AES_128_CBC_SHA256 0x00AE /* 174 */
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#define TLS_PSK_WITH_AES_256_CBC_SHA384 0x00AF /* 175 */
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#define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA 0xC004 /* 49156 */
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#define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA 0xC005 /* 49157 */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA 0xC009 /*TLSv1 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA1 */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA 0xC00A /*TLSv1 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA1 */
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#define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA 0xC00E /* 49166 */
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#define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA 0xC00F /* 49167 */
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#define TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 0xC012 /* 49170 */
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#define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 0xC013 /*TLSv1 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA1 */
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#define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 0xC014 /*TLSv1 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA1 */
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#define TLS_ECDH_anon_WITH_AES_128_CBC_SHA 0xC018 /* RFC 4492 */
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#define TLS_ECDH_anon_WITH_AES_256_CBC_SHA 0xC019 /* RFC 4492 */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 0xC023 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA256 */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 0xC024 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA384 */
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#define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 0xC025 /* 49189 */
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#define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 0xC026 /* 49190 */
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#define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 0xC027 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA256 */
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#define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 0xC028 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA384 */
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#define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 0xC029 /* 49193 */
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#define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 0xC02A /* 49194 */
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/* RFC 5288 "AES Galois Counter Mode (GCM) Cipher Suites for TLS" */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 0xC02B /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128) Mac=AEAD */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 0xC02C /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256) Mac=AEAD */
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#define TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 0xC02D /* 49197 */
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#define TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 0xC02E /* 49198 */
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#define TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 0xC02F /*TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD */
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#define TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 0xC030 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD */
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#define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 0xC031 /* 49201 */
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#define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 0xC032 /* 49202 */
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#define TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA 0xC035
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#define TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA 0xC036
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#define TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 0xC037
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#define TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 0xC038
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/* From http://wiki.mozilla.org/Security/Server_Side_TLS */
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/* and 'openssl ciphers -V -stdname' */
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#define TLS_RSA_WITH_AES_128_CCM 0xC09C /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM(128) Mac=AEAD */
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#define TLS_RSA_WITH_AES_256_CCM 0xC09D /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM(256) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_AES_128_CCM 0xC09E /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(128) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_AES_256_CCM 0xC09F /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(256) Mac=AEAD */
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#define TLS_RSA_WITH_AES_128_CCM_8 0xC0A0 /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM8(128) Mac=AEAD */
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#define TLS_RSA_WITH_AES_256_CCM_8 0xC0A1 /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM8(256) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_AES_128_CCM_8 0xC0A2 /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(128) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_AES_256_CCM_8 0xC0A3 /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(256) Mac=AEAD */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_CCM 0xC0AC /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(128) Mac=AEAD */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_CCM 0xC0AD /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(256) Mac=AEAD */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 0xC0AE /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM8(128) Mac=AEAD */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 0xC0AF /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM8(256) Mac=AEAD */
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#define TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA8 /*TLSv1.2 Kx=ECDH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
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#define TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA9 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
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#define TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 0xCCAA /*TLSv1.2 Kx=DH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
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#define TLS_AES_128_GCM_SHA256 0x1301 /*TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD */
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#define TLS_AES_256_GCM_SHA384 0x1302 /*TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD */
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#define TLS_CHACHA20_POLY1305_SHA256 0x1303 /*TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD */
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#define TLS_AES_128_CCM_SHA256 0x1304 /*TLSv1.3 Kx=any Au=any Enc=AESCCM(128) Mac=AEAD */
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/* Might go to libbb.h */
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#define TLS_MAX_CRYPTBLOCK_SIZE 16
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#define TLS_MAX_OUTBUF (1 << 14)
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enum {
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SHA_INSIZE = 64,
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AES128_KEYSIZE = 16,
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AES256_KEYSIZE = 32,
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RSA_PREMASTER_SIZE = 48,
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RECHDR_LEN = 5,
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/* 8 = 3+5. 3 extra bytes result in record data being 32-bit aligned */
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OUTBUF_PFX = 8 + AES_BLOCK_SIZE, /* header + IV */
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OUTBUF_SFX = TLS_MAX_MAC_SIZE + TLS_MAX_CRYPTBLOCK_SIZE, /* MAC + padding */
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// RFC 5246:
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// | 6.2.1. Fragmentation
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// | The record layer fragments information blocks into TLSPlaintext
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// | records carrying data in chunks of 2^14 bytes or less. Client
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// | message boundaries are not preserved in the record layer (i.e.,
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// | multiple client messages of the same ContentType MAY be coalesced
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// | into a single TLSPlaintext record, or a single message MAY be
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// | fragmented across several records)
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// |...
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// | length
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// | The length (in bytes) of the following TLSPlaintext.fragment.
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// | The length MUST NOT exceed 2^14.
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// |...
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// | 6.2.2. Record Compression and Decompression
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// |...
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// | Compression must be lossless and may not increase the content length
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// | by more than 1024 bytes. If the decompression function encounters a
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// | TLSCompressed.fragment that would decompress to a length in excess of
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// | 2^14 bytes, it MUST report a fatal decompression failure error.
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// |...
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// | length
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// | The length (in bytes) of the following TLSCompressed.fragment.
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// | The length MUST NOT exceed 2^14 + 1024.
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// |...
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// | 6.2.3. Record Payload Protection
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// | The encryption and MAC functions translate a TLSCompressed
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// | structure into a TLSCiphertext. The decryption functions reverse
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// | the process. The MAC of the record also includes a sequence
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// | number so that missing, extra, or repeated messages are
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// | detectable.
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// |...
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// | length
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// | The length (in bytes) of the following TLSCiphertext.fragment.
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// | The length MUST NOT exceed 2^14 + 2048.
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MAX_INBUF = RECHDR_LEN + (1 << 14) + 2048,
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/* Bits for tls->flags */
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NEED_EC_KEY = 1 << 0,
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GOT_CERT_RSA_KEY_ALG = 1 << 1,
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GOT_CERT_ECDSA_KEY_ALG = 1 << 2, // so far unused
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GOT_EC_KEY = 1 << 3,
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GOT_EC_CURVE_X25519 = 1 << 4, // else P256
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ENCRYPTION_AESGCM = 1 << 5, // else AES-SHA (or NULL-SHA if ALLOW_RSA_NULL_SHA256=1)
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ENCRYPT_ON_WRITE = 1 << 6,
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};
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struct record_hdr {
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uint8_t type;
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uint8_t proto_maj, proto_min;
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uint8_t len16_hi, len16_lo;
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};
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struct tls_handshake_data {
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/* In bbox, md5/sha1/sha256 ctx's are the same structure */
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md5sha_ctx_t handshake_hash_ctx;
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uint8_t client_and_server_rand32[2 * 32];
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uint8_t master_secret[48];
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//TODO: store just the DER key here, parse/use/delete it when sending client key
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//this way it will stay key type agnostic here.
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psRsaKey_t server_rsa_pub_key;
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/* peer's elliptic curve key data */
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/* for x25519, it contains one point in first 32 bytes */
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/* for P256, it contains x,y point pair, each 32 bytes long */
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uint8_t ecc_pub_key32[2 * 32];
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/* HANDSHAKE HASH: */
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//unsigned saved_client_hello_size;
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//uint8_t saved_client_hello[1];
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};
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static unsigned get24be(const uint8_t *p)
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{
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return 0x100*(0x100*p[0] + p[1]) + p[2];
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}
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#if TLS_DEBUG
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/* Nondestructively see the current hash value */
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# if TLS_DEBUG_HASH
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static unsigned sha_peek(md5sha_ctx_t *ctx, void *buffer)
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{
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md5sha_ctx_t ctx_copy = *ctx; /* struct copy */
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return sha_end(&ctx_copy, buffer);
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}
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# endif
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static void dump_hex(const char *fmt, const void *vp, int len)
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{
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char hexbuf[32 * 1024 + 4];
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const uint8_t *p = vp;
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bin2hex(hexbuf, (void*)p, len)[0] = '\0';
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dbg(fmt, hexbuf);
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}
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static void dump_tls_record(const void *vp, int len)
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{
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const uint8_t *p = vp;
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while (len > 0) {
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unsigned xhdr_len;
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if (len < RECHDR_LEN) {
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dump_hex("< |%s|\n", p, len);
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return;
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}
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xhdr_len = 0x100*p[3] + p[4];
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dbg("< hdr_type:%u ver:%u.%u len:%u", p[0], p[1], p[2], xhdr_len);
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p += RECHDR_LEN;
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len -= RECHDR_LEN;
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if (len >= 4 && p[-RECHDR_LEN] == RECORD_TYPE_HANDSHAKE) {
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unsigned len24 = get24be(p + 1);
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dbg(" type:%u len24:%u", p[0], len24);
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}
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if (xhdr_len > len)
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xhdr_len = len;
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dump_hex(" |%s|\n", p, xhdr_len);
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p += xhdr_len;
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len -= xhdr_len;
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}
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}
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#else
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# define dump_hex(...) ((void)0)
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# define dump_tls_record(...) ((void)0)
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#endif
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void FAST_FUNC tls_get_random(void *buf, unsigned len)
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{
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if (len != open_read_close("/dev/urandom", buf, len))
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xfunc_die();
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}
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static void xorbuf3(void *dst, const void *src1, const void *src2, unsigned count)
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{
|
|
uint8_t *d = dst;
|
|
const uint8_t *s1 = src1;
|
|
const uint8_t* s2 = src2;
|
|
while (count--)
|
|
*d++ = *s1++ ^ *s2++;
|
|
}
|
|
|
|
void FAST_FUNC xorbuf(void *dst, const void *src, unsigned count)
|
|
{
|
|
xorbuf3(dst, dst, src, count);
|
|
}
|
|
|
|
void FAST_FUNC xorbuf_aligned_AES_BLOCK_SIZE(void *dst, const void *src)
|
|
{
|
|
unsigned long *d = dst;
|
|
const unsigned long *s = src;
|
|
d[0] ^= s[0];
|
|
#if ULONG_MAX <= 0xffffffffffffffff
|
|
d[1] ^= s[1];
|
|
#if ULONG_MAX == 0xffffffff
|
|
d[2] ^= s[2];
|
|
d[3] ^= s[3];
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
#if !TLS_DEBUG_HASH
|
|
# define hash_handshake(tls, fmt, buffer, len) \
|
|
hash_handshake(tls, buffer, len)
|
|
#endif
|
|
static void hash_handshake(tls_state_t *tls, const char *fmt, const void *buffer, unsigned len)
|
|
{
|
|
md5sha_hash(&tls->hsd->handshake_hash_ctx, buffer, len);
|
|
#if TLS_DEBUG_HASH
|
|
{
|
|
uint8_t h[TLS_MAX_MAC_SIZE];
|
|
dump_hex(fmt, buffer, len);
|
|
dbg(" (%u bytes) ", (int)len);
|
|
len = sha_peek(&tls->hsd->handshake_hash_ctx, h);
|
|
if (ENABLE_FEATURE_TLS_SHA1 && len == SHA1_OUTSIZE)
|
|
dump_hex("sha1:%s\n", h, len);
|
|
else
|
|
if (len == SHA256_OUTSIZE)
|
|
dump_hex("sha256:%s\n", h, len);
|
|
else
|
|
dump_hex("sha???:%s\n", h, len);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#if !ENABLE_FEATURE_TLS_SHA1
|
|
# define TLS_MAC_SIZE(tls) SHA256_OUTSIZE
|
|
#else
|
|
# define TLS_MAC_SIZE(tls) (tls)->MAC_size
|
|
#endif
|
|
|
|
// RFC 2104:
|
|
// HMAC(key, text) based on a hash H (say, sha256) is:
|
|
// ipad = [0x36 x INSIZE]
|
|
// opad = [0x5c x INSIZE]
|
|
// HMAC(key, text) = H((key XOR opad) + H((key XOR ipad) + text))
|
|
//
|
|
// H(key XOR opad) and H(key XOR ipad) can be precomputed
|
|
// if we often need HMAC hmac with the same key.
|
|
//
|
|
// text is often given in disjoint pieces.
|
|
typedef struct hmac_precomputed {
|
|
md5sha_ctx_t hashed_key_xor_ipad;
|
|
md5sha_ctx_t hashed_key_xor_opad;
|
|
} hmac_precomputed_t;
|
|
|
|
typedef void md5sha_begin_func(md5sha_ctx_t *ctx) FAST_FUNC;
|
|
#if !ENABLE_FEATURE_TLS_SHA1
|
|
#define hmac_begin(pre,key,key_size,begin) \
|
|
hmac_begin(pre,key,key_size)
|
|
#define begin sha256_begin
|
|
#endif
|
|
static void hmac_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size, md5sha_begin_func *begin)
|
|
{
|
|
uint8_t key_xor_ipad[SHA_INSIZE];
|
|
uint8_t key_xor_opad[SHA_INSIZE];
|
|
// uint8_t tempkey[SHA1_OUTSIZE < SHA256_OUTSIZE ? SHA256_OUTSIZE : SHA1_OUTSIZE];
|
|
unsigned i;
|
|
|
|
// "The authentication key can be of any length up to INSIZE, the
|
|
// block length of the hash function. Applications that use keys longer
|
|
// than INSIZE bytes will first hash the key using H and then use the
|
|
// resultant OUTSIZE byte string as the actual key to HMAC."
|
|
if (key_size > SHA_INSIZE) {
|
|
bb_simple_error_msg_and_die("HMAC key>64"); //does not happen (yet?)
|
|
// md5sha_ctx_t ctx;
|
|
// begin(&ctx);
|
|
// md5sha_hash(&ctx, key, key_size);
|
|
// key_size = sha_end(&ctx, tempkey);
|
|
// //key = tempkey; - right? RIGHT? why does it work without this?
|
|
// // because SHA_INSIZE is 64, but hmac() is always called with
|
|
// // key_size = tls->MAC_size = SHA1/256_OUTSIZE (20 or 32),
|
|
// // and prf_hmac_sha256() -> hmac_sha256() key sizes are:
|
|
// // - RSA_PREMASTER_SIZE is 48
|
|
// // - CURVE25519_KEYSIZE is 32
|
|
// // - master_secret[] is 48
|
|
}
|
|
|
|
for (i = 0; i < key_size; i++) {
|
|
key_xor_ipad[i] = key[i] ^ 0x36;
|
|
key_xor_opad[i] = key[i] ^ 0x5c;
|
|
}
|
|
for (; i < SHA_INSIZE; i++) {
|
|
key_xor_ipad[i] = 0x36;
|
|
key_xor_opad[i] = 0x5c;
|
|
}
|
|
|
|
begin(&pre->hashed_key_xor_ipad);
|
|
begin(&pre->hashed_key_xor_opad);
|
|
md5sha_hash(&pre->hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE);
|
|
md5sha_hash(&pre->hashed_key_xor_opad, key_xor_opad, SHA_INSIZE);
|
|
}
|
|
#undef begin
|
|
|
|
static unsigned hmac_sha_precomputed_v(
|
|
hmac_precomputed_t *pre,
|
|
uint8_t *out,
|
|
va_list va)
|
|
{
|
|
uint8_t *text;
|
|
unsigned len;
|
|
|
|
/* pre->hashed_key_xor_ipad contains unclosed "H((key XOR ipad) +" state */
|
|
/* pre->hashed_key_xor_opad contains unclosed "H((key XOR opad) +" state */
|
|
|
|
/* calculate out = H((key XOR ipad) + text) */
|
|
while ((text = va_arg(va, uint8_t*)) != NULL) {
|
|
unsigned text_size = va_arg(va, unsigned);
|
|
md5sha_hash(&pre->hashed_key_xor_ipad, text, text_size);
|
|
}
|
|
len = sha_end(&pre->hashed_key_xor_ipad, out);
|
|
|
|
/* out = H((key XOR opad) + out) */
|
|
md5sha_hash(&pre->hashed_key_xor_opad, out, len);
|
|
return sha_end(&pre->hashed_key_xor_opad, out);
|
|
}
|
|
|
|
static unsigned hmac_sha_precomputed(hmac_precomputed_t *pre_init, uint8_t *out, ...)
|
|
{
|
|
hmac_precomputed_t pre;
|
|
va_list va;
|
|
unsigned len;
|
|
|
|
va_start(va, out);
|
|
pre = *pre_init; /* struct copy */
|
|
len = hmac_sha_precomputed_v(&pre, out, va);
|
|
va_end(va);
|
|
return len;
|
|
}
|
|
|
|
#if !ENABLE_FEATURE_TLS_SHA1
|
|
#define hmac(tls,out,key,key_size,...) \
|
|
hmac(out,key,key_size, __VA_ARGS__)
|
|
#endif
|
|
static unsigned hmac(tls_state_t *tls, uint8_t *out, uint8_t *key, unsigned key_size, ...)
|
|
{
|
|
hmac_precomputed_t pre;
|
|
va_list va;
|
|
unsigned len;
|
|
|
|
va_start(va, key_size);
|
|
|
|
hmac_begin(&pre, key, key_size,
|
|
(ENABLE_FEATURE_TLS_SHA1 && tls->MAC_size == SHA1_OUTSIZE)
|
|
? sha1_begin
|
|
: sha256_begin
|
|
);
|
|
len = hmac_sha_precomputed_v(&pre, out, va);
|
|
|
|
va_end(va);
|
|
return len;
|
|
}
|
|
|
|
// RFC 5246:
|
|
// 5. HMAC and the Pseudorandom Function
|
|
//...
|
|
// In this section, we define one PRF, based on HMAC. This PRF with the
|
|
// SHA-256 hash function is used for all cipher suites defined in this
|
|
// document and in TLS documents published prior to this document when
|
|
// TLS 1.2 is negotiated.
|
|
// ^^^^^^^^^^^^^ IMPORTANT!
|
|
// PRF uses sha256 regardless of cipher for all ciphers
|
|
// defined by RFC 5246. It's not sha1 for AES_128_CBC_SHA!
|
|
// However, for _SHA384 ciphers, it's sha384. See RFC 5288,5289.
|
|
//...
|
|
// P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
|
|
// HMAC_hash(secret, A(2) + seed) +
|
|
// HMAC_hash(secret, A(3) + seed) + ...
|
|
// where + indicates concatenation.
|
|
// A() is defined as:
|
|
// A(0) = seed
|
|
// A(1) = HMAC_hash(secret, A(0)) = HMAC_hash(secret, seed)
|
|
// A(i) = HMAC_hash(secret, A(i-1))
|
|
// P_hash can be iterated as many times as necessary to produce the
|
|
// required quantity of data. For example, if P_SHA256 is being used to
|
|
// create 80 bytes of data, it will have to be iterated three times
|
|
// (through A(3)), creating 96 bytes of output data; the last 16 bytes
|
|
// of the final iteration will then be discarded, leaving 80 bytes of
|
|
// output data.
|
|
//
|
|
// TLS's PRF is created by applying P_hash to the secret as:
|
|
//
|
|
// PRF(secret, label, seed) = P_<hash>(secret, label + seed)
|
|
//
|
|
// The label is an ASCII string.
|
|
//
|
|
// RFC 5288:
|
|
// For cipher suites ending with _SHA256, the PRF is the TLS PRF
|
|
// with SHA-256 as the hash function.
|
|
// For cipher suites ending with _SHA384, the PRF is the TLS PRF
|
|
// with SHA-384 as the hash function.
|
|
static void prf_hmac_sha256(/*tls_state_t *tls,*/
|
|
uint8_t *outbuf, unsigned outbuf_size,
|
|
uint8_t *secret, unsigned secret_size,
|
|
const char *label,
|
|
uint8_t *seed, unsigned seed_size)
|
|
{
|
|
hmac_precomputed_t pre;
|
|
uint8_t a[TLS_MAX_MAC_SIZE];
|
|
uint8_t *out_p = outbuf;
|
|
unsigned label_size = strlen(label);
|
|
unsigned MAC_size = SHA256_OUTSIZE;
|
|
|
|
/* In P_hash() calculation, "seed" is "label + seed": */
|
|
#define SEED label, label_size, seed, seed_size
|
|
#define A a, MAC_size
|
|
|
|
hmac_begin(&pre, secret, secret_size, sha256_begin);
|
|
|
|
/* A(1) = HMAC_hash(secret, seed) */
|
|
hmac_sha_precomputed(&pre, a, SEED, NULL);
|
|
|
|
for (;;) {
|
|
/* HMAC_hash(secret, A(1) + seed) */
|
|
if (outbuf_size <= MAC_size) {
|
|
/* Last, possibly incomplete, block */
|
|
/* (use a[] as temp buffer) */
|
|
hmac_sha_precomputed(&pre, a, A, SEED, NULL);
|
|
memcpy(out_p, a, outbuf_size);
|
|
return;
|
|
}
|
|
/* Not last block. Store directly to result buffer */
|
|
hmac_sha_precomputed(&pre, out_p, A, SEED, NULL);
|
|
out_p += MAC_size;
|
|
outbuf_size -= MAC_size;
|
|
/* A(2) = HMAC_hash(secret, A(1)) */
|
|
hmac_sha_precomputed(&pre, a, A, NULL);
|
|
}
|
|
#undef A
|
|
#undef SECRET
|
|
#undef SEED
|
|
}
|
|
|
|
static void bad_record_die(tls_state_t *tls, const char *expected, int len)
|
|
{
|
|
bb_error_msg("got bad TLS record (len:%d) while expecting %s", len, expected);
|
|
if (len > 0) {
|
|
uint8_t *p = tls->inbuf;
|
|
if (len > 99)
|
|
len = 99; /* don't flood, a few lines should be enough */
|
|
do {
|
|
fprintf(stderr, " %02x", *p++);
|
|
len--;
|
|
} while (len != 0);
|
|
fputc('\n', stderr);
|
|
}
|
|
xfunc_die();
|
|
}
|
|
|
|
static void tls_error_die(tls_state_t *tls, int line)
|
|
{
|
|
dump_tls_record(tls->inbuf, tls->ofs_to_buffered + tls->buffered_size);
|
|
bb_error_msg_and_die("tls error at line %d cipher:%04x", line, tls->cipher_id);
|
|
}
|
|
#define tls_error_die(tls) tls_error_die(tls, __LINE__)
|
|
|
|
#if 0 //UNUSED
|
|
static void tls_free_inbuf(tls_state_t *tls)
|
|
{
|
|
if (tls->buffered_size == 0) {
|
|
free(tls->inbuf);
|
|
tls->inbuf_size = 0;
|
|
tls->inbuf = NULL;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static void tls_free_outbuf(tls_state_t *tls)
|
|
{
|
|
free(tls->outbuf);
|
|
tls->outbuf_size = 0;
|
|
tls->outbuf = NULL;
|
|
}
|
|
|
|
static void *tls_get_outbuf(tls_state_t *tls, int len)
|
|
{
|
|
if (len > TLS_MAX_OUTBUF)
|
|
xfunc_die();
|
|
len += OUTBUF_PFX + OUTBUF_SFX;
|
|
if (tls->outbuf_size < len) {
|
|
tls->outbuf_size = len;
|
|
tls->outbuf = xrealloc(tls->outbuf, len);
|
|
}
|
|
return tls->outbuf + OUTBUF_PFX;
|
|
}
|
|
|
|
static void *tls_get_zeroed_outbuf(tls_state_t *tls, int len)
|
|
{
|
|
void *record = tls_get_outbuf(tls, len);
|
|
memset(record, 0, len);
|
|
return record;
|
|
}
|
|
|
|
static void xwrite_encrypted_and_hmac_signed(tls_state_t *tls, unsigned size, unsigned type)
|
|
{
|
|
uint8_t *buf = tls->outbuf + OUTBUF_PFX;
|
|
struct record_hdr *xhdr;
|
|
uint8_t padding_length;
|
|
|
|
xhdr = (void*)(buf - RECHDR_LEN);
|
|
if (!ALLOW_RSA_NULL_SHA256 /* if "no encryption" can't be selected */
|
|
|| tls->cipher_id != TLS_RSA_WITH_NULL_SHA256 /* or if it wasn't selected */
|
|
) {
|
|
xhdr = (void*)(buf - RECHDR_LEN - AES_BLOCK_SIZE); /* place for IV */
|
|
}
|
|
|
|
xhdr->type = type;
|
|
xhdr->proto_maj = TLS_MAJ;
|
|
xhdr->proto_min = TLS_MIN;
|
|
/* fake unencrypted record len for MAC calculation */
|
|
xhdr->len16_hi = size >> 8;
|
|
xhdr->len16_lo = size & 0xff;
|
|
|
|
/* Calculate MAC signature */
|
|
hmac(tls, buf + size, /* result */
|
|
tls->client_write_MAC_key, TLS_MAC_SIZE(tls),
|
|
&tls->write_seq64_be, sizeof(tls->write_seq64_be),
|
|
xhdr, RECHDR_LEN,
|
|
buf, size,
|
|
NULL
|
|
);
|
|
tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
|
|
|
|
size += TLS_MAC_SIZE(tls);
|
|
|
|
// RFC 5246:
|
|
// 6.2.3.1. Null or Standard Stream Cipher
|
|
//
|
|
// Stream ciphers (including BulkCipherAlgorithm.null; see Appendix A.6)
|
|
// convert TLSCompressed.fragment structures to and from stream
|
|
// TLSCiphertext.fragment structures.
|
|
//
|
|
// stream-ciphered struct {
|
|
// opaque content[TLSCompressed.length];
|
|
// opaque MAC[SecurityParameters.mac_length];
|
|
// } GenericStreamCipher;
|
|
//
|
|
// The MAC is generated as:
|
|
// MAC(MAC_write_key, seq_num +
|
|
// TLSCompressed.type +
|
|
// TLSCompressed.version +
|
|
// TLSCompressed.length +
|
|
// TLSCompressed.fragment);
|
|
// where "+" denotes concatenation.
|
|
// seq_num
|
|
// The sequence number for this record.
|
|
// MAC
|
|
// The MAC algorithm specified by SecurityParameters.mac_algorithm.
|
|
//
|
|
// Note that the MAC is computed before encryption. The stream cipher
|
|
// encrypts the entire block, including the MAC.
|
|
//...
|
|
// Appendix C. Cipher Suite Definitions
|
|
//...
|
|
// MAC Algorithm mac_length mac_key_length
|
|
// -------- ----------- ---------- --------------
|
|
// SHA HMAC-SHA1 20 20
|
|
// SHA256 HMAC-SHA256 32 32
|
|
if (ALLOW_RSA_NULL_SHA256
|
|
&& tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
|
|
) {
|
|
/* No encryption, only signing */
|
|
xhdr->len16_hi = size >> 8;
|
|
xhdr->len16_lo = size & 0xff;
|
|
dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
|
|
xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
|
|
dbg("wrote %u bytes (NULL crypt, SHA256 hash)\n", size);
|
|
return;
|
|
}
|
|
|
|
// 6.2.3.2. CBC Block Cipher
|
|
// For block ciphers (such as 3DES or AES), the encryption and MAC
|
|
// functions convert TLSCompressed.fragment structures to and from block
|
|
// TLSCiphertext.fragment structures.
|
|
// struct {
|
|
// opaque IV[SecurityParameters.record_iv_length];
|
|
// block-ciphered struct {
|
|
// opaque content[TLSCompressed.length];
|
|
// opaque MAC[SecurityParameters.mac_length];
|
|
// uint8 padding[GenericBlockCipher.padding_length];
|
|
// uint8 padding_length;
|
|
// };
|
|
// } GenericBlockCipher;
|
|
//...
|
|
// IV
|
|
// The Initialization Vector (IV) SHOULD be chosen at random, and
|
|
// MUST be unpredictable. Note that in versions of TLS prior to 1.1,
|
|
// there was no IV field (...). For block ciphers, the IV length is
|
|
// of length SecurityParameters.record_iv_length, which is equal to the
|
|
// SecurityParameters.block_size.
|
|
// padding
|
|
// Padding that is added to force the length of the plaintext to be
|
|
// an integral multiple of the block cipher's block length.
|
|
// padding_length
|
|
// The padding length MUST be such that the total size of the
|
|
// GenericBlockCipher structure is a multiple of the cipher's block
|
|
// length. Legal values range from zero to 255, inclusive.
|
|
//...
|
|
// Appendix C. Cipher Suite Definitions
|
|
//...
|
|
// Key IV Block
|
|
// Cipher Type Material Size Size
|
|
// ------------ ------ -------- ---- -----
|
|
// AES_128_CBC Block 16 16 16
|
|
// AES_256_CBC Block 32 16 16
|
|
|
|
tls_get_random(buf - AES_BLOCK_SIZE, AES_BLOCK_SIZE); /* IV */
|
|
dbg("before crypt: 5 hdr + %u data + %u hash bytes\n",
|
|
size - TLS_MAC_SIZE(tls), TLS_MAC_SIZE(tls));
|
|
|
|
/* Fill IV and padding in outbuf */
|
|
// RFC is talking nonsense:
|
|
// "Padding that is added to force the length of the plaintext to be
|
|
// an integral multiple of the block cipher's block length."
|
|
// WRONG. _padding+padding_length_, not just _padding_,
|
|
// pads the data.
|
|
// IOW: padding_length is the last byte of padding[] array,
|
|
// contrary to what RFC depicts.
|
|
//
|
|
// What actually happens is that there is always padding.
|
|
// If you need one byte to reach BLOCKSIZE, this byte is 0x00.
|
|
// If you need two bytes, they are both 0x01.
|
|
// If you need three, they are 0x02,0x02,0x02. And so on.
|
|
// If you need no bytes to reach BLOCKSIZE, you have to pad a full
|
|
// BLOCKSIZE with bytes of value (BLOCKSIZE-1).
|
|
// It's ok to have more than minimum padding, but we do minimum.
|
|
padding_length = (~size) & (AES_BLOCK_SIZE - 1);
|
|
do {
|
|
buf[size++] = padding_length; /* padding */
|
|
} while ((size & (AES_BLOCK_SIZE - 1)) != 0);
|
|
|
|
/* Encrypt content+MAC+padding in place */
|
|
aes_cbc_encrypt(
|
|
&tls->aes_encrypt, /* selects 128/256 */
|
|
buf - AES_BLOCK_SIZE, /* IV */
|
|
buf, size, /* plaintext */
|
|
buf /* ciphertext */
|
|
);
|
|
|
|
/* Write out */
|
|
dbg("writing 5 + %u IV + %u encrypted bytes, padding_length:0x%02x\n",
|
|
AES_BLOCK_SIZE, size, padding_length);
|
|
size += AES_BLOCK_SIZE; /* + IV */
|
|
xhdr->len16_hi = size >> 8;
|
|
xhdr->len16_lo = size & 0xff;
|
|
dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
|
|
xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
|
|
dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
|
|
}
|
|
|
|
/* Example how GCM encryption combines nonce, aad, input and generates
|
|
* "header | exp_nonce | encrypted output | tag":
|
|
* nonce:0d 6a 26 31 00 00 00 00 00 00 00 01 (implicit 4 bytes (derived from master secret), then explicit 8 bytes)
|
|
* aad: 00 00 00 00 00 00 00 01 17 03 03 00 1c
|
|
* in: 47 45 54 20 2f 69 6e 64 65 78 2e 68 74 6d 6c 20 48 54 54 50 2f 31 2e 30 0d 0a 0d 0a "GET /index.html HTTP/1.0\r\n\r\n" (0x1c bytes)
|
|
* out: f7 8a b2 8f 78 0e f6 d5 76 17 2e b5 6d 46 59 56 8b 46 9f 0b d9 2c 35 28 13 66 19 be
|
|
* tag: c2 86 ce 4a 50 4a d0 aa 50 b3 76 5c 49 2a 3f 33
|
|
* sent: 17 03 03 00 34|00 00 00 00 00 00 00 01|f7 8a b2 8f 78 0e f6 d5 76 17 2e b5 6d 46 59 56 8b 46 9f 0b d9 2c 35 28 13 66 19 be|c2 86 ce 4a 50 4a d0 aa 50 b3 76 5c 49 2a 3f 33
|
|
* .............................................^^ buf points here
|
|
*/
|
|
static void xwrite_encrypted_aesgcm(tls_state_t *tls, unsigned size, unsigned type)
|
|
{
|
|
#define COUNTER(v) (*(uint32_t*)(v + 12))
|
|
|
|
uint8_t aad[13 + 3] ALIGNED_long; /* +3 creates [16] buffer, simplifying GHASH() */
|
|
uint8_t nonce[12 + 4] ALIGNED_long; /* +4 creates space for AES block counter */
|
|
uint8_t scratch[AES_BLOCK_SIZE] ALIGNED_long; //[16]
|
|
uint8_t authtag[AES_BLOCK_SIZE] ALIGNED_long; //[16]
|
|
uint8_t *buf;
|
|
struct record_hdr *xhdr;
|
|
unsigned remaining;
|
|
unsigned cnt;
|
|
uint64_t t64;
|
|
|
|
buf = tls->outbuf + OUTBUF_PFX; /* see above for the byte it points to */
|
|
dump_hex("xwrite_encrypted_aesgcm plaintext:%s\n", buf, size);
|
|
|
|
xhdr = (void*)(buf - 8 - RECHDR_LEN);
|
|
xhdr->type = type; /* do it here so that "type" param no longer used */
|
|
|
|
aad[8] = type;
|
|
aad[9] = TLS_MAJ;
|
|
aad[10] = TLS_MIN;
|
|
aad[11] = size >> 8;
|
|
/* set aad[12], and clear aad[13..15] */
|
|
COUNTER(aad) = SWAP_LE32(size & 0xff);
|
|
|
|
memcpy(nonce, tls->client_write_IV, 4);
|
|
t64 = tls->write_seq64_be;
|
|
move_to_unaligned64(nonce + 4, t64);
|
|
move_to_unaligned64(aad, t64);
|
|
move_to_unaligned64(buf - 8, t64);
|
|
/* seq64 is not used later in this func, can increment here */
|
|
tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(t64));
|
|
|
|
cnt = 1;
|
|
remaining = size;
|
|
while (remaining != 0) {
|
|
unsigned n;
|
|
|
|
cnt++;
|
|
COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */
|
|
aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
|
|
n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining;
|
|
xorbuf(buf, scratch, n);
|
|
buf += n;
|
|
remaining -= n;
|
|
}
|
|
|
|
aesgcm_GHASH(tls->H, aad, /*sizeof(aad),*/ tls->outbuf + OUTBUF_PFX, size, authtag /*, sizeof(authtag)*/);
|
|
COUNTER(nonce) = htonl(1);
|
|
aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
|
|
xorbuf_aligned_AES_BLOCK_SIZE(authtag, scratch);
|
|
|
|
memcpy(buf, authtag, sizeof(authtag));
|
|
|
|
/* Write out */
|
|
xhdr = (void*)(tls->outbuf + OUTBUF_PFX - 8 - RECHDR_LEN);
|
|
size += 8 + sizeof(authtag);
|
|
/*xhdr->type = type; - already is */
|
|
xhdr->proto_maj = TLS_MAJ;
|
|
xhdr->proto_min = TLS_MIN;
|
|
xhdr->len16_hi = size >> 8;
|
|
xhdr->len16_lo = size & 0xff;
|
|
size += RECHDR_LEN;
|
|
dump_raw_out(">> %s\n", xhdr, size);
|
|
xwrite(tls->ofd, xhdr, size);
|
|
dbg("wrote %u bytes\n", size);
|
|
#undef COUNTER
|
|
}
|
|
|
|
static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type)
|
|
{
|
|
if (!(tls->flags & ENCRYPTION_AESGCM)) {
|
|
xwrite_encrypted_and_hmac_signed(tls, size, type);
|
|
return;
|
|
}
|
|
xwrite_encrypted_aesgcm(tls, size, type);
|
|
}
|
|
|
|
static void xwrite_handshake_record(tls_state_t *tls, unsigned size)
|
|
{
|
|
uint8_t *buf = tls->outbuf + OUTBUF_PFX;
|
|
struct record_hdr *xhdr = (void*)(buf - RECHDR_LEN);
|
|
|
|
xhdr->type = RECORD_TYPE_HANDSHAKE;
|
|
xhdr->proto_maj = TLS_MAJ;
|
|
xhdr->proto_min = TLS_MIN;
|
|
xhdr->len16_hi = size >> 8;
|
|
xhdr->len16_lo = size & 0xff;
|
|
dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
|
|
xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
|
|
dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
|
|
}
|
|
|
|
static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size)
|
|
{
|
|
if (!(tls->flags & ENCRYPT_ON_WRITE)) {
|
|
uint8_t *buf;
|
|
|
|
xwrite_handshake_record(tls, size);
|
|
/* Handshake hash does not include record headers */
|
|
buf = tls->outbuf + OUTBUF_PFX;
|
|
hash_handshake(tls, ">> hash:%s", buf, size);
|
|
return;
|
|
}
|
|
xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE);
|
|
}
|
|
|
|
static int tls_has_buffered_record(tls_state_t *tls)
|
|
{
|
|
int buffered = tls->buffered_size;
|
|
struct record_hdr *xhdr;
|
|
int rec_size;
|
|
|
|
if (buffered < RECHDR_LEN)
|
|
return 0;
|
|
xhdr = (void*)(tls->inbuf + tls->ofs_to_buffered);
|
|
rec_size = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
|
|
if (buffered < rec_size)
|
|
return 0;
|
|
return rec_size;
|
|
}
|
|
|
|
static const char *alert_text(int code)
|
|
{
|
|
//10 unexpected_message
|
|
//20 bad_record_mac
|
|
//21 decryption_failed
|
|
//22 record_overflow
|
|
//30 decompression_failure
|
|
//40 handshake_failure
|
|
//41 no_certificate
|
|
//42 bad_certificate
|
|
//43 unsupported_certificate
|
|
//44 certificate_revoked
|
|
//45 certificate_expired
|
|
//46 certificate_unknown
|
|
//47 illegal_parameter
|
|
//48 unknown_ca
|
|
//49 access_denied
|
|
//50 decode_error
|
|
//51 decrypt_error
|
|
//52 too_many_cids_requested
|
|
//60 export_restriction
|
|
//70 protocol_version
|
|
//71 insufficient_security
|
|
//80 internal_error
|
|
//86 inappropriate_fallback
|
|
//90 user_canceled
|
|
//100 no_renegotiation
|
|
//109 missing_extension
|
|
//110 unsupported_extension
|
|
//111 certificate_unobtainable
|
|
//112 unrecognized_name
|
|
//113 bad_certificate_status_response
|
|
//114 bad_certificate_hash_value
|
|
//115 unknown_psk_identity
|
|
//116 certificate_required
|
|
//120 no_application_protocol
|
|
switch (code) {
|
|
case 20: return "bad MAC";
|
|
case 50: return "decode error";
|
|
case 40: return "handshake failure";
|
|
case 51: return "decrypt error";
|
|
case 80: return "internal error";
|
|
case 112: return "unrecognized name";
|
|
}
|
|
return itoa(code);
|
|
}
|
|
|
|
static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size)
|
|
{
|
|
#define COUNTER(v) (*(uint32_t*)(v + 12))
|
|
|
|
//uint8_t aad[13 + 3] ALIGNED_long; /* +3 creates [16] buffer, simplifying GHASH() */
|
|
uint8_t nonce[12 + 4] ALIGNED_long; /* +4 creates space for AES block counter */
|
|
uint8_t scratch[AES_BLOCK_SIZE] ALIGNED_long; //[16]
|
|
//uint8_t authtag[AES_BLOCK_SIZE] ALIGNED_long; //[16]
|
|
unsigned remaining;
|
|
unsigned cnt;
|
|
|
|
//memcpy(aad, buf, 8);
|
|
//aad[8] = type;
|
|
//aad[9] = TLS_MAJ;
|
|
//aad[10] = TLS_MIN;
|
|
//aad[11] = size >> 8;
|
|
///* set aad[12], and clear aad[13..15] */
|
|
//COUNTER(aad) = SWAP_LE32(size & 0xff);
|
|
|
|
memcpy(nonce, tls->server_write_IV, 4);
|
|
memcpy(nonce + 4, buf, 8);
|
|
|
|
cnt = 1;
|
|
remaining = size;
|
|
while (remaining != 0) {
|
|
unsigned n;
|
|
|
|
cnt++;
|
|
COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */
|
|
aes_encrypt_one_block(&tls->aes_decrypt, nonce, scratch);
|
|
n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining;
|
|
xorbuf3(buf, scratch, buf + 8, n);
|
|
buf += n;
|
|
remaining -= n;
|
|
}
|
|
|
|
//aesgcm_GHASH(tls->H, aad, tls->inbuf + RECHDR_LEN, size, authtag);
|
|
//COUNTER(nonce) = htonl(1);
|
|
//aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
|
|
//xorbuf_aligned_AES_BLOCK_SIZE(authtag, scratch);
|
|
|
|
//memcmp(buf, authtag, sizeof(authtag)) || DIE("HASH DOES NOT MATCH!");
|
|
#undef COUNTER
|
|
}
|
|
|
|
static int tls_xread_record(tls_state_t *tls, const char *expected)
|
|
{
|
|
struct record_hdr *xhdr;
|
|
int sz;
|
|
int total;
|
|
int target;
|
|
|
|
again:
|
|
dbg("ofs_to_buffered:%u buffered_size:%u\n", tls->ofs_to_buffered, tls->buffered_size);
|
|
total = tls->buffered_size;
|
|
if (total != 0) {
|
|
memmove(tls->inbuf, tls->inbuf + tls->ofs_to_buffered, total);
|
|
//dbg("<< remaining at %d [%d] ", tls->ofs_to_buffered, total);
|
|
//dump_raw_in("<< %s\n", tls->inbuf, total);
|
|
}
|
|
errno = 0;
|
|
target = MAX_INBUF;
|
|
for (;;) {
|
|
int rem;
|
|
|
|
if (total >= RECHDR_LEN && target == MAX_INBUF) {
|
|
xhdr = (void*)tls->inbuf;
|
|
target = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
|
|
|
|
if (target > MAX_INBUF /* malformed input (too long) */
|
|
|| xhdr->proto_maj != TLS_MAJ
|
|
|| xhdr->proto_min != TLS_MIN
|
|
) {
|
|
sz = total < target ? total : target;
|
|
bad_record_die(tls, expected, sz);
|
|
}
|
|
dbg("xhdr type:%d ver:%d.%d len:%d\n",
|
|
xhdr->type, xhdr->proto_maj, xhdr->proto_min,
|
|
0x100 * xhdr->len16_hi + xhdr->len16_lo
|
|
);
|
|
}
|
|
/* if total >= target, we have a full packet (and possibly more)... */
|
|
if (total - target >= 0)
|
|
break;
|
|
/* input buffer is grown only as needed */
|
|
rem = tls->inbuf_size - total;
|
|
if (rem == 0) {
|
|
tls->inbuf_size += MAX_INBUF / 8;
|
|
if (tls->inbuf_size > MAX_INBUF)
|
|
tls->inbuf_size = MAX_INBUF;
|
|
dbg("inbuf_size:%d\n", tls->inbuf_size);
|
|
rem = tls->inbuf_size - total;
|
|
tls->inbuf = xrealloc(tls->inbuf, tls->inbuf_size);
|
|
}
|
|
sz = safe_read(tls->ifd, tls->inbuf + total, rem);
|
|
if (sz <= 0) {
|
|
if (sz == 0 && total == 0) {
|
|
/* "Abrupt" EOF, no TLS shutdown (seen from kernel.org) */
|
|
dbg("EOF (without TLS shutdown) from peer\n");
|
|
tls->buffered_size = 0;
|
|
goto end;
|
|
}
|
|
bb_perror_msg_and_die("short read, have only %d", total);
|
|
}
|
|
dump_raw_in("<< %s\n", tls->inbuf + total, sz);
|
|
total += sz;
|
|
}
|
|
tls->buffered_size = total - target;
|
|
tls->ofs_to_buffered = target;
|
|
//dbg("<< stashing at %d [%d] ", tls->ofs_to_buffered, tls->buffered_size);
|
|
//dump_hex("<< %s\n", tls->inbuf + tls->ofs_to_buffered, tls->buffered_size);
|
|
|
|
sz = target - RECHDR_LEN;
|
|
|
|
/* Needs to be decrypted? */
|
|
if (tls->min_encrypted_len_on_read != 0) {
|
|
if (sz < (int)tls->min_encrypted_len_on_read)
|
|
bb_error_msg_and_die("bad encrypted len:%u", sz);
|
|
|
|
if (tls->flags & ENCRYPTION_AESGCM) {
|
|
/* AESGCM */
|
|
uint8_t *p = tls->inbuf + RECHDR_LEN;
|
|
|
|
sz -= 8 + AES_BLOCK_SIZE; /* we will overwrite nonce, drop hash */
|
|
tls_aesgcm_decrypt(tls, p, sz);
|
|
dbg("encrypted size:%u\n", sz);
|
|
} else
|
|
if (tls->min_encrypted_len_on_read > TLS_MAC_SIZE(tls)) {
|
|
/* AES+SHA */
|
|
uint8_t *p = tls->inbuf + RECHDR_LEN;
|
|
int padding_len;
|
|
|
|
if (sz & (AES_BLOCK_SIZE-1))
|
|
bb_error_msg_and_die("bad encrypted len:%u", sz);
|
|
|
|
/* Decrypt content+MAC+padding, moving it over IV in the process */
|
|
sz -= AES_BLOCK_SIZE; /* we will overwrite IV now */
|
|
aes_cbc_decrypt(
|
|
&tls->aes_decrypt, /* selects 128/256 */
|
|
p, /* IV */
|
|
p + AES_BLOCK_SIZE, sz, /* ciphertext */
|
|
p /* plaintext */
|
|
);
|
|
padding_len = p[sz - 1];
|
|
dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[0], padding_len);
|
|
padding_len++;
|
|
sz -= TLS_MAC_SIZE(tls) + padding_len; /* drop MAC and padding */
|
|
} else {
|
|
/* if nonzero, then it's TLS_RSA_WITH_NULL_SHA256: drop MAC */
|
|
/* else: no encryption yet on input, subtract zero = NOP */
|
|
sz -= tls->min_encrypted_len_on_read;
|
|
}
|
|
}
|
|
if (sz < 0)
|
|
bb_simple_error_msg_and_die("encrypted data too short");
|
|
|
|
//dump_hex("<< %s\n", tls->inbuf, RECHDR_LEN + sz);
|
|
|
|
xhdr = (void*)tls->inbuf;
|
|
if (xhdr->type == RECORD_TYPE_ALERT && sz >= 2) {
|
|
uint8_t *p = tls->inbuf + RECHDR_LEN;
|
|
dbg("ALERT size:%d level:%d description:%d\n", sz, p[0], p[1]);
|
|
if (p[0] == 2) { /* fatal */
|
|
bb_error_msg_and_die("TLS %s from peer (alert code %d): %s",
|
|
"error",
|
|
p[1], alert_text(p[1])
|
|
);
|
|
}
|
|
if (p[0] == 1) { /* warning */
|
|
if (p[1] == 0) { /* "close_notify" warning: it's EOF */
|
|
dbg("EOF (TLS encoded) from peer\n");
|
|
sz = 0;
|
|
goto end;
|
|
}
|
|
//This possibly needs to be cached and shown only if
|
|
//a fatal alert follows
|
|
// bb_error_msg("TLS %s from peer (alert code %d): %s",
|
|
// "warning",
|
|
// p[1], alert_text(p[1])
|
|
// );
|
|
/* discard it, get next record */
|
|
goto again;
|
|
}
|
|
/* p[0] not 1 or 2: not defined in protocol */
|
|
sz = 0;
|
|
goto end;
|
|
}
|
|
|
|
/* RFC 5246 is not saying it explicitly, but sha256 hash
|
|
* in our FINISHED record must include data of incoming packets too!
|
|
*/
|
|
if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE
|
|
/* HANDSHAKE HASH: */
|
|
// && do_we_know_which_hash_to_use /* server_hello() might not know it in the future! */
|
|
) {
|
|
hash_handshake(tls, "<< hash:%s", tls->inbuf + RECHDR_LEN, sz);
|
|
}
|
|
end:
|
|
dbg("got block len:%u\n", sz);
|
|
return sz;
|
|
}
|
|
|
|
static void binary_to_pstm(pstm_int *pstm_n, uint8_t *bin_ptr, unsigned len)
|
|
{
|
|
pstm_init_for_read_unsigned_bin(/*pool:*/ NULL, pstm_n, len);
|
|
pstm_read_unsigned_bin(pstm_n, bin_ptr, len);
|
|
//return bin_ptr + len;
|
|
}
|
|
|
|
/*
|
|
* DER parsing routines
|
|
*/
|
|
static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
|
|
{
|
|
unsigned len, len1;
|
|
|
|
if (end - der < 2)
|
|
xfunc_die();
|
|
// if ((der[0] & 0x1f) == 0x1f) /* not single-byte item code? */
|
|
// xfunc_die();
|
|
|
|
len = der[1]; /* maybe it's short len */
|
|
if (len >= 0x80) {
|
|
/* no, it's long */
|
|
|
|
if (len == 0x80 || end - der < (int)(len - 0x7e)) {
|
|
/* 0x80 is "0 bytes of len", invalid DER: must use short len if can */
|
|
/* need 3 or 4 bytes for 81, 82 */
|
|
xfunc_die();
|
|
}
|
|
|
|
len1 = der[2]; /* if (len == 0x81) it's "ii 81 xx", fetch xx */
|
|
if (len > 0x82) {
|
|
/* >0x82 is "3+ bytes of len", should not happen realistically */
|
|
xfunc_die();
|
|
}
|
|
if (len == 0x82) { /* it's "ii 82 xx yy" */
|
|
len1 = 0x100*len1 + der[3];
|
|
der += 1; /* skip [yy] */
|
|
}
|
|
der += 1; /* skip [xx] */
|
|
len = len1;
|
|
// if (len < 0x80)
|
|
// xfunc_die(); /* invalid DER: must use short len if can */
|
|
}
|
|
der += 2; /* skip [code]+[1byte] */
|
|
|
|
if (end - der < (int)len)
|
|
xfunc_die();
|
|
*bodyp = der;
|
|
|
|
return len;
|
|
}
|
|
|
|
static uint8_t *enter_der_item(uint8_t *der, uint8_t **endp)
|
|
{
|
|
uint8_t *new_der;
|
|
unsigned len = get_der_len(&new_der, der, *endp);
|
|
dbg_der("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
|
|
/* Move "end" position to cover only this item */
|
|
*endp = new_der + len;
|
|
return new_der;
|
|
}
|
|
|
|
static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
|
|
{
|
|
uint8_t *new_der;
|
|
unsigned len = get_der_len(&new_der, der, end);
|
|
/* Skip body */
|
|
new_der += len;
|
|
dbg_der("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
|
|
return new_der;
|
|
}
|
|
|
|
static void der_binary_to_pstm(pstm_int *pstm_n, uint8_t *der, uint8_t *end)
|
|
{
|
|
uint8_t *bin_ptr;
|
|
unsigned len = get_der_len(&bin_ptr, der, end);
|
|
|
|
dbg_der("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
|
|
binary_to_pstm(pstm_n, bin_ptr, len);
|
|
}
|
|
|
|
static void find_key_in_der_cert(tls_state_t *tls, uint8_t *der, int len)
|
|
{
|
|
/* Certificate is a DER-encoded data structure. Each DER element has a length,
|
|
* which makes it easy to skip over large compound elements of any complexity
|
|
* without parsing them. Example: partial decode of kernel.org certificate:
|
|
* SEQ 0x05ac/1452 bytes (Certificate): 308205ac
|
|
* SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
|
|
* [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
|
|
* INTEGER (version): 0201 02
|
|
* INTEGER 0x11 bytes (serialNumber): 0211 00 9f85bf664b0cddafca508679501b2be4
|
|
* //^^^^^^note: matrixSSL also allows [ASN_CONTEXT_SPECIFIC | ASN_PRIMITIVE | 2] = 0x82 type
|
|
* SEQ 0x0d bytes (signatureAlgo): 300d
|
|
* OID 9 bytes: 0609 2a864886f70d01010b (OID_SHA256_RSA_SIG 42.134.72.134.247.13.1.1.11)
|
|
* NULL: 0500
|
|
* SEQ 0x5f bytes (issuer): 305f
|
|
* SET 11 bytes: 310b
|
|
* SEQ 9 bytes: 3009
|
|
* OID 3 bytes: 0603 550406
|
|
* Printable string "FR": 1302 4652
|
|
* SET 14 bytes: 310e
|
|
* SEQ 12 bytes: 300c
|
|
* OID 3 bytes: 0603 550408
|
|
* Printable string "Paris": 1305 5061726973
|
|
* SET 14 bytes: 310e
|
|
* SEQ 12 bytes: 300c
|
|
* OID 3 bytes: 0603 550407
|
|
* Printable string "Paris": 1305 5061726973
|
|
* SET 14 bytes: 310e
|
|
* SEQ 12 bytes: 300c
|
|
* OID 3 bytes: 0603 55040a
|
|
* Printable string "Gandi": 1305 47616e6469
|
|
* SET 32 bytes: 3120
|
|
* SEQ 30 bytes: 301e
|
|
* OID 3 bytes: 0603 550403
|
|
* Printable string "Gandi Standard SSL CA 2": 1317 47616e6469205374616e646172642053534c2043412032
|
|
* SEQ 30 bytes (validity): 301e
|
|
* TIME "161011000000Z": 170d 3136313031313030303030305a
|
|
* TIME "191011235959Z": 170d 3139313031313233353935395a
|
|
* SEQ 0x5b/91 bytes (subject): 305b //I did not decode this
|
|
* 3121301f060355040b1318446f6d61696e20436f
|
|
* 6e74726f6c2056616c6964617465643121301f06
|
|
* 0355040b1318506f73697469766553534c204d75
|
|
* 6c74692d446f6d61696e31133011060355040313
|
|
* 0a6b65726e656c2e6f7267
|
|
* SEQ 0x01a2/418 bytes (subjectPublicKeyInfo): 308201a2
|
|
* SEQ 13 bytes (algorithm): 300d
|
|
* OID 9 bytes: 0609 2a864886f70d010101 (OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1)
|
|
* NULL: 0500
|
|
* BITSTRING 0x018f/399 bytes (publicKey): 0382018f
|
|
* ????: 00
|
|
* //after the zero byte, it appears key itself uses DER encoding:
|
|
* SEQ 0x018a/394 bytes: 3082018a
|
|
* INTEGER 0x0181/385 bytes (modulus): 02820181
|
|
* 00b1ab2fc727a3bef76780c9349bf3
|
|
* ...24 more blocks of 15 bytes each...
|
|
* 90e895291c6bc8693b65
|
|
* INTEGER 3 bytes (exponent): 0203 010001
|
|
* [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0x3] 0x01e5 bytes (X509v3 extensions): a38201e5
|
|
* SEQ 0x01e1 bytes: 308201e1
|
|
* ...
|
|
* Certificate is a sequence of three elements:
|
|
* tbsCertificate (SEQ)
|
|
* signatureAlgorithm (AlgorithmIdentifier)
|
|
* signatureValue (BIT STRING)
|
|
*
|
|
* In turn, tbsCertificate is a sequence of:
|
|
* version
|
|
* serialNumber
|
|
* signatureAlgo (AlgorithmIdentifier)
|
|
* issuer (Name, has complex structure)
|
|
* validity (Validity, SEQ of two Times)
|
|
* subject (Name)
|
|
* subjectPublicKeyInfo (SEQ)
|
|
* ...
|
|
*
|
|
* subjectPublicKeyInfo is a sequence of:
|
|
* algorithm (AlgorithmIdentifier)
|
|
* publicKey (BIT STRING)
|
|
*
|
|
* We need Certificate.tbsCertificate.subjectPublicKeyInfo.publicKey
|
|
*
|
|
* Example of an ECDSA key:
|
|
* SEQ 0x59 bytes (subjectPublicKeyInfo): 3059
|
|
* SEQ 0x13 bytes (algorithm): 3013
|
|
* OID 7 bytes: 0607 2a8648ce3d0201 (OID_ECDSA_KEY_ALG 42.134.72.206.61.2.1)
|
|
* OID 8 bytes: 0608 2a8648ce3d030107 (OID_EC_prime256v1 42.134.72.206.61.3.1.7)
|
|
* BITSTRING 0x42 bytes (publicKey): 0342
|
|
* 0004 53af f65e 50cc 7959 7e29 0171 c75c
|
|
* 7335 e07d f45b 9750 b797 3a38 aebb 2ac6
|
|
* 8329 2748 e77e 41cb d482 2ce6 05ec a058
|
|
* f3ab d561 2f4c d845 9ad3 7252 e3de bd3b
|
|
* 9012
|
|
*/
|
|
uint8_t *end = der + len;
|
|
|
|
/* enter "Certificate" item: [der, end) will be only Cert */
|
|
der = enter_der_item(der, &end);
|
|
|
|
/* enter "tbsCertificate" item: [der, end) will be only tbsCert */
|
|
der = enter_der_item(der, &end);
|
|
|
|
/*
|
|
* Skip version field only if it is present. For a v1 certificate, the
|
|
* version field won't be present since v1 is the default value for the
|
|
* version field and fields with default values should be omitted (see
|
|
* RFC 5280 sections 4.1 and 4.1.2.1). If the version field is present
|
|
* it will have a tag class of 2 (context-specific), bit 6 as 1
|
|
* (constructed), and a tag number of 0 (see ITU-T X.690 sections 8.1.2
|
|
* and 8.14).
|
|
*/
|
|
/* bits 7-6: 10 */
|
|
/* bit 5: 1 */
|
|
/* bits 4-0: 00000 */
|
|
if (der[0] == 0xa0)
|
|
der = skip_der_item(der, end); /* version */
|
|
|
|
/* skip up to subjectPublicKeyInfo */
|
|
der = skip_der_item(der, end); /* serialNumber */
|
|
der = skip_der_item(der, end); /* signatureAlgo */
|
|
der = skip_der_item(der, end); /* issuer */
|
|
der = skip_der_item(der, end); /* validity */
|
|
der = skip_der_item(der, end); /* subject */
|
|
|
|
/* enter subjectPublicKeyInfo */
|
|
der = enter_der_item(der, &end);
|
|
{ /* check subjectPublicKeyInfo.algorithm */
|
|
static const uint8_t OID_RSA_KEY_ALG[] ALIGN1 = {
|
|
0x30,0x0d, // SEQ 13 bytes
|
|
0x06,0x09, 0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x01,0x01, //OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1
|
|
//0x05,0x00, // NULL
|
|
};
|
|
static const uint8_t OID_ECDSA_KEY_ALG[] ALIGN1 = {
|
|
0x30,0x13, // SEQ 0x13 bytes
|
|
0x06,0x07, 0x2a,0x86,0x48,0xce,0x3d,0x02,0x01, //OID_ECDSA_KEY_ALG 42.134.72.206.61.2.1
|
|
//allow any curve code for now...
|
|
// 0x06,0x08, 0x2a,0x86,0x48,0xce,0x3d,0x03,0x01,0x07, //OID_EC_prime256v1 42.134.72.206.61.3.1.7
|
|
//RFC 3279:
|
|
//42.134.72.206.61.3 is ellipticCurve
|
|
//42.134.72.206.61.3.0 is c-TwoCurve
|
|
//42.134.72.206.61.3.1 is primeCurve
|
|
//42.134.72.206.61.3.1.7 is curve_secp256r1
|
|
};
|
|
if (memcmp(der, OID_RSA_KEY_ALG, sizeof(OID_RSA_KEY_ALG)) == 0) {
|
|
dbg("RSA key\n");
|
|
tls->flags |= GOT_CERT_RSA_KEY_ALG;
|
|
} else
|
|
if (memcmp(der, OID_ECDSA_KEY_ALG, sizeof(OID_ECDSA_KEY_ALG)) == 0) {
|
|
dbg("ECDSA key\n");
|
|
//UNUSED: tls->flags |= GOT_CERT_ECDSA_KEY_ALG;
|
|
} else
|
|
bb_simple_error_msg_and_die("not RSA or ECDSA cert");
|
|
}
|
|
|
|
if (tls->flags & GOT_CERT_RSA_KEY_ALG) {
|
|
/* parse RSA key: */
|
|
//based on getAsnRsaPubKey(), pkcs1ParsePrivBin() is also of note
|
|
/* skip subjectPublicKeyInfo.algorithm */
|
|
der = skip_der_item(der, end);
|
|
/* enter subjectPublicKeyInfo.publicKey */
|
|
//die_if_not_this_der_type(der, end, 0x03); /* must be BITSTRING */
|
|
der = enter_der_item(der, &end);
|
|
|
|
dbg("key bytes:%u, first:0x%02x\n", (int)(end - der), der[0]);
|
|
if (end - der < 14)
|
|
xfunc_die();
|
|
/* example format:
|
|
* ignore bits: 00
|
|
* SEQ 0x018a/394 bytes: 3082018a
|
|
* INTEGER 0x0181/385 bytes (modulus): 02820181 XX...XXX
|
|
* INTEGER 3 bytes (exponent): 0203 010001
|
|
*/
|
|
if (*der != 0) /* "ignore bits", should be 0 */
|
|
xfunc_die();
|
|
der++;
|
|
der = enter_der_item(der, &end); /* enter SEQ */
|
|
/* memset(tls->hsd->server_rsa_pub_key, 0, sizeof(tls->hsd->server_rsa_pub_key)); - already is */
|
|
der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.N, der, end); /* modulus */
|
|
der = skip_der_item(der, end);
|
|
der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.e, der, end); /* exponent */
|
|
tls->hsd->server_rsa_pub_key.size = pstm_unsigned_bin_size(&tls->hsd->server_rsa_pub_key.N);
|
|
dbg("server_rsa_pub_key.size:%d\n", tls->hsd->server_rsa_pub_key.size);
|
|
}
|
|
/* else: ECDSA key. It is not used for generating encryption keys,
|
|
* it is used only to sign the EC public key (which comes in ServerKey message).
|
|
* Since we do not verify cert validity, verifying signature on EC public key
|
|
* wouldn't add any security. Thus, we do nothing here.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* TLS Handshake routines
|
|
*/
|
|
static int tls_xread_handshake_block(tls_state_t *tls, int min_len)
|
|
{
|
|
struct record_hdr *xhdr;
|
|
int len = tls_xread_record(tls, "handshake record");
|
|
|
|
xhdr = (void*)tls->inbuf;
|
|
if (len < min_len
|
|
|| xhdr->type != RECORD_TYPE_HANDSHAKE
|
|
) {
|
|
bad_record_die(tls, "handshake record", len);
|
|
}
|
|
dbg("got HANDSHAKE\n");
|
|
return len;
|
|
}
|
|
|
|
static ALWAYS_INLINE void fill_handshake_record_hdr(void *buf, unsigned type, unsigned len)
|
|
{
|
|
struct handshake_hdr {
|
|
uint8_t type;
|
|
uint8_t len24_hi, len24_mid, len24_lo;
|
|
} *h = buf;
|
|
|
|
len -= 4;
|
|
h->type = type;
|
|
h->len24_hi = len >> 16;
|
|
h->len24_mid = len >> 8;
|
|
h->len24_lo = len & 0xff;
|
|
}
|
|
|
|
static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
|
|
{
|
|
#define NUM_CIPHERS (0 \
|
|
+ 4 * ENABLE_FEATURE_TLS_SHA1 \
|
|
+ ALLOW_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 \
|
|
+ ALLOW_ECDHE_RSA_WITH_AES_128_CBC_SHA256 \
|
|
+ ALLOW_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 \
|
|
+ ALLOW_ECDHE_RSA_WITH_AES_128_GCM_SHA256 \
|
|
+ 2 * ENABLE_FEATURE_TLS_SHA1 \
|
|
+ ALLOW_RSA_WITH_AES_128_CBC_SHA256 \
|
|
+ ALLOW_RSA_WITH_AES_256_CBC_SHA256 \
|
|
+ ALLOW_RSA_WITH_AES_128_GCM_SHA256 \
|
|
+ ALLOW_RSA_NULL_SHA256 \
|
|
)
|
|
static const uint8_t ciphers[] = {
|
|
0x00,2 * (1 + NUM_CIPHERS), //len16_be
|
|
0x00,0xFF, //not a cipher - TLS_EMPTY_RENEGOTIATION_INFO_SCSV
|
|
/* ^^^^^^ RFC 5746 Renegotiation Indication Extension - some servers will refuse to work with us otherwise */
|
|
#if ENABLE_FEATURE_TLS_SHA1
|
|
0xC0,0x09, // 1 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - ok: wget https://is.gd/
|
|
0xC0,0x0A, // 2 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - ok: wget https://is.gd/
|
|
0xC0,0x13, // 3 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA
|
|
0xC0,0x14, // 4 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES256-SHA (might fail with older openssl)
|
|
// 0xC0,0x18, // TLS_ECDH_anon_WITH_AES_128_CBC_SHA
|
|
// 0xC0,0x19, // TLS_ECDH_anon_WITH_AES_256_CBC_SHA
|
|
#endif
|
|
#if ALLOW_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
|
|
0xC0,0x23, // 5 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - ok: wget https://is.gd/
|
|
#endif
|
|
// 0xC0,0x24, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
|
|
#if ALLOW_ECDHE_RSA_WITH_AES_128_CBC_SHA256
|
|
0xC0,0x27, // 6 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA256
|
|
#endif
|
|
// 0xC0,0x28, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
|
|
#if ALLOW_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
|
|
0xC0,0x2B, // 7 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - ok: wget https://is.gd/
|
|
#endif
|
|
// 0xC0,0x2C, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - wget https://is.gd/: "TLS error from peer (alert code 20): bad MAC"
|
|
//TODO: GCM_SHA384 ciphers can be supported, only need sha384-based PRF?
|
|
#if ALLOW_ECDHE_RSA_WITH_AES_128_GCM_SHA256
|
|
0xC0,0x2F, // 8 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-GCM-SHA256
|
|
#endif
|
|
// 0xC0,0x30, // TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher ECDHE-RSA-AES256-GCM-SHA384: "decryption failed or bad record mac"
|
|
//possibly these too:
|
|
#if ENABLE_FEATURE_TLS_SHA1
|
|
// 0xC0,0x35, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA
|
|
// 0xC0,0x36, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA
|
|
#endif
|
|
// 0xC0,0x37, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256
|
|
// 0xC0,0x38, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
|
|
#if ENABLE_FEATURE_TLS_SHA1
|
|
0x00,0x2F, // 9 TLS_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher AES128-SHA
|
|
0x00,0x35, //10 TLS_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher AES256-SHA
|
|
#endif
|
|
#if ALLOW_RSA_WITH_AES_128_CBC_SHA256
|
|
0x00,0x3C, //11 TLS_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher AES128-SHA256
|
|
#endif
|
|
#if ALLOW_RSA_WITH_AES_256_CBC_SHA256
|
|
0x00,0x3D, //12 TLS_RSA_WITH_AES_256_CBC_SHA256 - ok: openssl s_server ... -cipher AES256-SHA256
|
|
#endif
|
|
#if ALLOW_RSA_WITH_AES_128_GCM_SHA256
|
|
0x00,0x9C, //13 TLS_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher AES128-GCM-SHA256
|
|
#endif
|
|
// 0x00,0x9D, // TLS_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher AES256-GCM-SHA384: "decryption failed or bad record mac"
|
|
#if ALLOW_RSA_NULL_SHA256
|
|
0x00,0x3B, // TLS_RSA_WITH_NULL_SHA256
|
|
#endif
|
|
0x01,0x00, //not a cipher - comprtypes_len, comprtype
|
|
};
|
|
struct client_hello {
|
|
uint8_t type;
|
|
uint8_t len24_hi, len24_mid, len24_lo;
|
|
uint8_t proto_maj, proto_min;
|
|
uint8_t rand32[32];
|
|
uint8_t session_id_len;
|
|
/* uint8_t session_id[]; */
|
|
uint8_t cipherid_len16_hi, cipherid_len16_lo;
|
|
uint8_t cipherid[2 * (1 + NUM_CIPHERS)]; /* actually variable */
|
|
uint8_t comprtypes_len;
|
|
uint8_t comprtypes[1]; /* actually variable */
|
|
};
|
|
// https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml
|
|
static const uint8_t extensions[] = {
|
|
// is.gd responds with "handshake failure" to our hello if there's no supported_groups
|
|
0x00,0x0a, //extension_type: "supported_groups"
|
|
0x00,2 * (1 + ALLOW_CURVE_P256 + ALLOW_CURVE_X25519), //ext len
|
|
0x00,2 * (0 + ALLOW_CURVE_P256 + ALLOW_CURVE_X25519), //list len
|
|
#if ALLOW_CURVE_P256
|
|
0x00,0x17, //curve_secp256r1 (aka P256, aka prime256v1)
|
|
#endif
|
|
//0x00,0x18, //curve_secp384r1
|
|
//0x00,0x19, //curve_secp521r1
|
|
#if ALLOW_CURVE_X25519
|
|
0x00,0x1d, //curve_x25519 (RFC 7748)
|
|
#endif
|
|
//0x00,0x1e, //curve_x448 (RFC 7748)
|
|
|
|
//0x00,0x0b,0x00,0x04,0x03,0x00,0x01,0x02, //extension_type: "ec_point_formats"
|
|
//0x00,0x16,0x00,0x00, //extension_type: "encrpypt-then-mac"
|
|
//0x00,0x17,0x00,0x00, //extension_type: "extended_master"
|
|
//0x00,0x23,0x00,0x00, //extension_type: "session_ticket"
|
|
|
|
// kojipkgs.fedoraproject.org responds with alert code 80 ("internal error")
|
|
// to our hello without signature_algorithms.
|
|
// It is satisfied with just 0x04,0x01.
|
|
0x00,0x0d, //extension_type: "signature_algorithms" (RFC5246 section 7.4.1.4.1):
|
|
#define SIGALGS (3 + 3 * ENABLE_FEATURE_TLS_SHA1)
|
|
0x00,2 * (1 + SIGALGS), //ext len
|
|
0x00,2 * (0 + SIGALGS), //list len
|
|
//Format: two bytes
|
|
// byte 1: 0:none,1:md5,2:sha1,3:sha224,4:sha256,5:sha384,6:sha512
|
|
// byte 2: 1:rsa,2:dsa,3:ecdsa
|
|
// (note that TLS 1.3 changes this, see RFC8446 section 4.2.3)
|
|
#if ENABLE_FEATURE_TLS_SHA1
|
|
0x02,0x01, //sha1 + rsa
|
|
0x02,0x02, //sha1 + dsa
|
|
0x02,0x03, //sha1 + ecdsa
|
|
#endif
|
|
0x04,0x01, //sha256 + rsa - kojipkgs.fedoraproject.org wants this
|
|
0x04,0x02, //sha256 + dsa
|
|
0x04,0x03, //sha256 + ecdsa
|
|
// GNU Wget 1.18 to cdn.kernel.org sends these extensions:
|
|
// 0055
|
|
// 0005 0005 0100000000 - status_request
|
|
// 0000 0013 0011 00 000e 63646e 2e 6b65726e656c 2e 6f7267 - server_name
|
|
// ff01 0001 00 - renegotiation_info
|
|
// 0023 0000 - session_ticket
|
|
// 000a 0008 0006001700180019 - supported_groups
|
|
// 000b 0002 0100 - ec_point_formats
|
|
// 000d 0016 0014 0401 0403 0501 0503 0601 0603 0301 0303 0201 0203 - signature_algorithms
|
|
// wolfssl library sends this option, RFC 7627 (closes a security weakness, some servers may require it. TODO?):
|
|
// 0017 0000 - extended master secret
|
|
};
|
|
struct client_hello *record;
|
|
uint8_t *ptr;
|
|
int len;
|
|
int ext_len;
|
|
int sni_len = sni ? strnlen(sni, 127 - 5) : 0;
|
|
|
|
ext_len = 0;
|
|
ext_len += sizeof(extensions);
|
|
if (sni_len)
|
|
ext_len += 9 + sni_len;
|
|
|
|
/* +2 is for "len of all extensions" 2-byte field */
|
|
len = sizeof(*record) + 2 + ext_len;
|
|
record = tls_get_zeroed_outbuf(tls, len);
|
|
|
|
fill_handshake_record_hdr(record, HANDSHAKE_CLIENT_HELLO, len);
|
|
record->proto_maj = TLS_MAJ; /* the "requested" version of the protocol, */
|
|
record->proto_min = TLS_MIN; /* can be higher than one in record headers */
|
|
tls_get_random(record->rand32, sizeof(record->rand32));
|
|
if (TLS_DEBUG_FIXED_SECRETS)
|
|
memset(record->rand32, 0x11, sizeof(record->rand32));
|
|
/* record->session_id_len = 0; - already is */
|
|
|
|
BUILD_BUG_ON(sizeof(ciphers) != 2 * (1 + 1 + NUM_CIPHERS + 1));
|
|
memcpy(&record->cipherid_len16_hi, ciphers, sizeof(ciphers));
|
|
|
|
ptr = (void*)(record + 1);
|
|
*ptr++ = ext_len >> 8;
|
|
*ptr++ = ext_len;
|
|
if (sni_len) {
|
|
//ptr[0] = 0; //
|
|
//ptr[1] = 0; //extension_type
|
|
//ptr[2] = 0; //
|
|
ptr[3] = sni_len + 5; //list len
|
|
//ptr[4] = 0; //
|
|
ptr[5] = sni_len + 3; //len of 1st SNI
|
|
//ptr[6] = 0; //name type
|
|
//ptr[7] = 0; //
|
|
ptr[8] = sni_len; //name len
|
|
ptr = mempcpy(&ptr[9], sni, sni_len);
|
|
}
|
|
memcpy(ptr, extensions, sizeof(extensions));
|
|
|
|
tls->hsd = xzalloc(sizeof(*tls->hsd));
|
|
/* HANDSHAKE HASH: ^^^ + len if need to save saved_client_hello */
|
|
memcpy(tls->hsd->client_and_server_rand32, record->rand32, sizeof(record->rand32));
|
|
/* HANDSHAKE HASH:
|
|
tls->hsd->saved_client_hello_size = len;
|
|
memcpy(tls->hsd->saved_client_hello, record, len);
|
|
*/
|
|
dbg(">> CLIENT_HELLO\n");
|
|
/* Can hash immediately only if we know which MAC hash to use.
|
|
* So far we do know: it's sha256:
|
|
*/
|
|
sha256_begin(&tls->hsd->handshake_hash_ctx);
|
|
xwrite_and_update_handshake_hash(tls, len);
|
|
/* if this would become infeasible: save tls->hsd->saved_client_hello,
|
|
* use "xwrite_handshake_record(tls, len)" here,
|
|
* and hash saved_client_hello later.
|
|
*/
|
|
}
|
|
|
|
static void get_server_hello(tls_state_t *tls)
|
|
{
|
|
struct server_hello {
|
|
struct record_hdr xhdr;
|
|
uint8_t type;
|
|
uint8_t len24_hi, len24_mid, len24_lo;
|
|
uint8_t proto_maj, proto_min;
|
|
uint8_t rand32[32]; /* first 4 bytes are unix time in BE format */
|
|
uint8_t session_id_len;
|
|
uint8_t session_id[32];
|
|
uint8_t cipherid_hi, cipherid_lo;
|
|
uint8_t comprtype;
|
|
/* extensions may follow, but only those which client offered in its Hello */
|
|
};
|
|
|
|
struct server_hello *hp;
|
|
uint8_t *cipherid;
|
|
uint8_t cipherid1;
|
|
int len, len24;
|
|
|
|
len = tls_xread_handshake_block(tls, 74 - 32);
|
|
|
|
hp = (void*)tls->inbuf;
|
|
// 74 bytes:
|
|
// 02 000046 03|03 58|78|cf|c1 50|a5|49|ee|7e|29|48|71|fe|97|fa|e8|2d|19|87|72|90|84|9d|37|a3|f0|cb|6f|5f|e3|3c|2f |20 |d8|1a|78|96|52|d6|91|01|24|b3|d6|5b|b7|d0|6c|b3|e1|78|4e|3c|95|de|74|a0|ba|eb|a7|3a|ff|bd|a2|bf |00|9c |00|
|
|
//SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
|
|
if (hp->type != HANDSHAKE_SERVER_HELLO
|
|
|| hp->len24_hi != 0
|
|
|| hp->len24_mid != 0
|
|
/* hp->len24_lo checked later */
|
|
|| hp->proto_maj != TLS_MAJ
|
|
|| hp->proto_min != TLS_MIN
|
|
) {
|
|
bad_record_die(tls, "'server hello'", len);
|
|
}
|
|
|
|
cipherid = &hp->cipherid_hi;
|
|
len24 = hp->len24_lo;
|
|
if (hp->session_id_len != 32) {
|
|
if (hp->session_id_len != 0)
|
|
bad_record_die(tls, "'server hello'", len);
|
|
|
|
// session_id_len == 0: no session id
|
|
// "The server
|
|
// may return an empty session_id to indicate that the session will
|
|
// not be cached and therefore cannot be resumed."
|
|
cipherid -= 32;
|
|
len24 += 32; /* what len would be if session id would be present */
|
|
}
|
|
|
|
if (len24 < 70)
|
|
bad_record_die(tls, "'server hello'", len);
|
|
dbg("<< SERVER_HELLO\n");
|
|
|
|
memcpy(tls->hsd->client_and_server_rand32 + 32, hp->rand32, sizeof(hp->rand32));
|
|
|
|
/* Set up encryption params based on selected cipher */
|
|
#if 0
|
|
0xC0,0x09, // 1 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - ok: wget https://is.gd/
|
|
0xC0,0x0A, // 2 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - ok: wget https://is.gd/
|
|
0xC0,0x13, // 3 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA
|
|
0xC0,0x14, // 4 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES256-SHA (might fail with older openssl)
|
|
// 0xC0,0x18, // TLS_ECDH_anon_WITH_AES_128_CBC_SHA
|
|
// 0xC0,0x19, // TLS_ECDH_anon_WITH_AES_256_CBC_SHA
|
|
0xC0,0x23, // 5 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - ok: wget https://is.gd/
|
|
// 0xC0,0x24, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
|
|
0xC0,0x27, // 6 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA256
|
|
// 0xC0,0x28, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
|
|
0xC0,0x2B, // 7 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - ok: wget https://is.gd/
|
|
// 0xC0,0x2C, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - wget https://is.gd/: "TLS error from peer (alert code 20): bad MAC"
|
|
0xC0,0x2F, // 8 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-GCM-SHA256
|
|
// 0xC0,0x30, // TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher ECDHE-RSA-AES256-GCM-SHA384: "decryption failed or bad record mac"
|
|
//possibly these too:
|
|
// 0xC0,0x35, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA
|
|
// 0xC0,0x36, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA
|
|
// 0xC0,0x37, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256
|
|
// 0xC0,0x38, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
|
|
0x00,0x2F, // 9 TLS_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher AES128-SHA
|
|
0x00,0x35, //10 TLS_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher AES256-SHA
|
|
0x00,0x3C, //11 TLS_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher AES128-SHA256
|
|
0x00,0x3D, //12 TLS_RSA_WITH_AES_256_CBC_SHA256 - ok: openssl s_server ... -cipher AES256-SHA256
|
|
0x00,0x9C, //13 TLS_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher AES128-GCM-SHA256
|
|
// 0x00,0x9D, // TLS_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher AES256-GCM-SHA384: "decryption failed or bad record mac"
|
|
0x00,0x3B, // TLS_RSA_WITH_NULL_SHA256
|
|
#endif
|
|
cipherid1 = cipherid[1];
|
|
tls->cipher_id = 0x100 * cipherid[0] + cipherid1;
|
|
tls->key_size = AES256_KEYSIZE;
|
|
tls->MAC_size = SHA256_OUTSIZE;
|
|
/*tls->IV_size = 0; - already is */
|
|
if (cipherid[0] == 0xC0) {
|
|
/* All C0xx are ECDHE */
|
|
tls->flags |= NEED_EC_KEY;
|
|
if (cipherid1 & 1) {
|
|
/* Odd numbered C0xx use AES128 (even ones use AES256) */
|
|
tls->key_size = AES128_KEYSIZE;
|
|
}
|
|
if (ENABLE_FEATURE_TLS_SHA1 && cipherid1 <= 0x19) {
|
|
tls->MAC_size = SHA1_OUTSIZE;
|
|
} else
|
|
if (cipherid1 >= 0x2B && cipherid1 <= 0x30) {
|
|
/* C02B,2C,2F,30 are AES-GCM */
|
|
tls->flags |= ENCRYPTION_AESGCM;
|
|
tls->MAC_size = 0;
|
|
tls->IV_size = 4;
|
|
}
|
|
} else {
|
|
/* All 00xx are RSA */
|
|
if ((ENABLE_FEATURE_TLS_SHA1 && cipherid1 == 0x2F)
|
|
|| cipherid1 == 0x3C
|
|
|| cipherid1 == 0x9C
|
|
) {
|
|
tls->key_size = AES128_KEYSIZE;
|
|
}
|
|
if (ENABLE_FEATURE_TLS_SHA1 && cipherid1 <= 0x35) {
|
|
tls->MAC_size = SHA1_OUTSIZE;
|
|
} else
|
|
if (cipherid1 == 0x9C /*|| cipherid1 == 0x9D*/) {
|
|
/* 009C,9D are AES-GCM */
|
|
tls->flags |= ENCRYPTION_AESGCM;
|
|
tls->MAC_size = 0;
|
|
tls->IV_size = 4;
|
|
}
|
|
}
|
|
dbg("server chose cipher %04x\n", tls->cipher_id);
|
|
dbg("key_size:%u MAC_size:%u IV_size:%u\n", tls->key_size, tls->MAC_size, tls->IV_size);
|
|
|
|
/* Handshake hash eventually destined to FINISHED record
|
|
* is sha256 regardless of cipher
|
|
* (at least for all ciphers defined by RFC5246).
|
|
* It's not sha1 for AES_128_CBC_SHA - only MAC is sha1, not this hash.
|
|
*/
|
|
/* HANDSHAKE HASH:
|
|
sha256_begin(&tls->hsd->handshake_hash_ctx);
|
|
hash_handshake(tls, ">> client hello hash:%s",
|
|
tls->hsd->saved_client_hello, tls->hsd->saved_client_hello_size
|
|
);
|
|
hash_handshake(tls, "<< server hello hash:%s",
|
|
tls->inbuf + RECHDR_LEN, len
|
|
);
|
|
*/
|
|
}
|
|
|
|
static void get_server_cert(tls_state_t *tls)
|
|
{
|
|
struct record_hdr *xhdr;
|
|
uint8_t *certbuf;
|
|
int len, len1;
|
|
|
|
len = tls_xread_handshake_block(tls, 10);
|
|
|
|
xhdr = (void*)tls->inbuf;
|
|
certbuf = (void*)(xhdr + 1);
|
|
if (certbuf[0] != HANDSHAKE_CERTIFICATE)
|
|
bad_record_die(tls, "certificate", len);
|
|
dbg("<< CERTIFICATE\n");
|
|
// 4392 bytes:
|
|
// 0b 00|11|24 00|11|21 00|05|b0 30|82|05|ac|30|82|04|94|a0|03|02|01|02|02|11|00|9f|85|bf|66|4b|0c|dd|af|ca|50|86|79|50|1b|2b|e4|30|0d...
|
|
//Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
|
|
len1 = get24be(certbuf + 1);
|
|
if (len1 > len - 4) tls_error_die(tls);
|
|
len = len1;
|
|
len1 = get24be(certbuf + 4);
|
|
if (len1 > len - 3) tls_error_die(tls);
|
|
len = len1;
|
|
len1 = get24be(certbuf + 7);
|
|
if (len1 > len - 3) tls_error_die(tls);
|
|
len = len1;
|
|
|
|
if (len)
|
|
find_key_in_der_cert(tls, certbuf + 10, len);
|
|
}
|
|
|
|
/* On input, len is known to be >= 4.
|
|
* The record is known to be SERVER_KEY_EXCHANGE.
|
|
*/
|
|
static void process_server_key(tls_state_t *tls, int len)
|
|
{
|
|
struct record_hdr *xhdr;
|
|
uint8_t *keybuf;
|
|
int len1;
|
|
uint32_t t32;
|
|
|
|
xhdr = (void*)tls->inbuf;
|
|
keybuf = (void*)(xhdr + 1);
|
|
//seen from is.gd: it selects curve_x25519:
|
|
// 0c 00006e //SERVER_KEY_EXCHANGE, len
|
|
// 03 //curve_type: named curve
|
|
// 001d //curve_x25519
|
|
//server-chosen EC point, and then signed_params
|
|
// (RFC 8422: "A hash of the params, with the signature
|
|
// appropriate to that hash applied. The private key corresponding
|
|
// to the certified public key in the server's Certificate message is
|
|
// used for signing.")
|
|
//follow. Format unclear/guessed:
|
|
// 20 //eccPubKeyLen
|
|
// 25511923d73b70dd2f60e66ba2f3fda31a9c25170963c7a3a972e481dbb2835d //eccPubKey (32bytes)
|
|
// 0203 //hashSigAlg: 2:SHA1 (4:SHA256 5:SHA384 6:SHA512), 3:ECDSA (1:RSA)
|
|
// 0046 //len (16bit)
|
|
// 30 44 //SEQ, len
|
|
// 02 20 //INTEGER, len
|
|
// 2e18e7c2a9badd0a70cd3059a6ab114539b9f5163568911147386cd77ed7c412 //32bytes
|
|
//this item ^^^^^ is sometimes 33 bytes (with all container sizes also +1)
|
|
// 02 20 //INTEGER, len
|
|
// 64523d6216cb94c43c9b20e377d8c52c55be6703fd6730a155930c705eaf3af6 //32bytes
|
|
//same about this item ^^^^^
|
|
|
|
//seen from ftp.openbsd.org
|
|
//(which only accepts ECDHE-RSA-AESnnn-GCM-SHAnnn and ECDHE-RSA-CHACHA20-POLY1305 ciphers):
|
|
// 0c 000228 //SERVER_KEY_EXCHANGE, len
|
|
// 03 //curve_type: named curve
|
|
// 001d //curve_x25519
|
|
// 20 //eccPubKeyLen
|
|
// eef7a15c43b71a4c7eaa48a39369399cc4332e569ec90a83274cc92596705c1a //eccPubKey
|
|
// 0401 //hashSigAlg: 4:SHA256, 1:RSA
|
|
// 0200 //len
|
|
// //0x200 bytes follow
|
|
|
|
/* Get and verify length */
|
|
len1 = get24be(keybuf + 1);
|
|
if (len1 > len - 4) tls_error_die(tls);
|
|
len = len1;
|
|
if (len < (1+2+1+32)) tls_error_die(tls);
|
|
keybuf += 4;
|
|
|
|
#if BB_BIG_ENDIAN
|
|
# define _0x03001741 0x03001741
|
|
# define _0x03001d20 0x03001d20
|
|
#else
|
|
# define _0x03001741 0x41170003
|
|
# define _0x03001d20 0x201d0003
|
|
#endif
|
|
move_from_unaligned32(t32, keybuf);
|
|
keybuf += 4;
|
|
switch (t32) {
|
|
case _0x03001d20: //curve_x25519
|
|
dbg("got x25519 eccPubKey\n");
|
|
tls->flags |= GOT_EC_CURVE_X25519;
|
|
memcpy(tls->hsd->ecc_pub_key32, keybuf, 32);
|
|
break;
|
|
case _0x03001741: //curve_secp256r1 (aka P256)
|
|
dbg("got P256 eccPubKey\n");
|
|
/* P256 point can be transmitted odd- or even-compressed
|
|
* (first byte is 3 or 2) or uncompressed (4).
|
|
*/
|
|
if (*keybuf++ != 4)
|
|
bb_simple_error_msg_and_die("compressed EC points not supported");
|
|
memcpy(tls->hsd->ecc_pub_key32, keybuf, 2 * 32);
|
|
break;
|
|
default:
|
|
bb_error_msg_and_die("elliptic curve is not x25519 or P256: 0x%08x", t32);
|
|
}
|
|
|
|
tls->flags |= GOT_EC_KEY;
|
|
}
|
|
|
|
static void send_empty_client_cert(tls_state_t *tls)
|
|
{
|
|
struct client_empty_cert {
|
|
uint8_t type;
|
|
uint8_t len24_hi, len24_mid, len24_lo;
|
|
uint8_t cert_chain_len24_hi, cert_chain_len24_mid, cert_chain_len24_lo;
|
|
};
|
|
struct client_empty_cert *record;
|
|
|
|
record = tls_get_zeroed_outbuf(tls, sizeof(*record));
|
|
//fill_handshake_record_hdr(record, HANDSHAKE_CERTIFICATE, sizeof(*record));
|
|
//record->cert_chain_len24_hi = 0;
|
|
//record->cert_chain_len24_mid = 0;
|
|
//record->cert_chain_len24_lo = 0;
|
|
// same as above:
|
|
record->type = HANDSHAKE_CERTIFICATE;
|
|
record->len24_lo = 3;
|
|
|
|
dbg(">> CERTIFICATE\n");
|
|
xwrite_and_update_handshake_hash(tls, sizeof(*record));
|
|
}
|
|
|
|
static void send_client_key_exchange(tls_state_t *tls)
|
|
{
|
|
struct client_key_exchange {
|
|
uint8_t type;
|
|
uint8_t len24_hi, len24_mid, len24_lo;
|
|
uint8_t key[2 + 4 * 1024]; // size??
|
|
};
|
|
//FIXME: better size estimate
|
|
struct client_key_exchange *record = tls_get_zeroed_outbuf(tls, sizeof(*record));
|
|
uint8_t premaster[RSA_PREMASTER_SIZE > EC_CURVE_KEYSIZE ? RSA_PREMASTER_SIZE : EC_CURVE_KEYSIZE];
|
|
int premaster_size;
|
|
int len;
|
|
|
|
if (!(tls->flags & NEED_EC_KEY)) {
|
|
/* RSA */
|
|
if (!(tls->flags & GOT_CERT_RSA_KEY_ALG))
|
|
bb_simple_error_msg_and_die("server cert is not RSA");
|
|
|
|
tls_get_random(premaster, RSA_PREMASTER_SIZE);
|
|
if (TLS_DEBUG_FIXED_SECRETS)
|
|
memset(premaster, 0x44, RSA_PREMASTER_SIZE);
|
|
// RFC 5246
|
|
// "Note: The version number in the PreMasterSecret is the version
|
|
// offered by the client in the ClientHello.client_version, not the
|
|
// version negotiated for the connection."
|
|
premaster[0] = TLS_MAJ;
|
|
premaster[1] = TLS_MIN;
|
|
dump_hex("premaster:%s\n", premaster, sizeof(premaster));
|
|
len = psRsaEncryptPub(/*pool:*/ NULL,
|
|
/* psRsaKey_t* */ &tls->hsd->server_rsa_pub_key,
|
|
premaster, /*inlen:*/ RSA_PREMASTER_SIZE,
|
|
record->key + 2, sizeof(record->key) - 2,
|
|
data_param_ignored
|
|
);
|
|
/* keylen16 exists for RSA (in TLS, not in SSL), but not for some other key types */
|
|
record->key[0] = len >> 8;
|
|
record->key[1] = len & 0xff;
|
|
len += 2;
|
|
premaster_size = RSA_PREMASTER_SIZE;
|
|
} else {
|
|
/* ECDHE */
|
|
if (!(tls->flags & GOT_EC_KEY))
|
|
bb_simple_error_msg_and_die("server did not provide EC key");
|
|
|
|
if (tls->flags & GOT_EC_CURVE_X25519) {
|
|
/* ECDHE, curve x25519 */
|
|
dbg("computing x25519_premaster\n");
|
|
curve_x25519_compute_pubkey_and_premaster(
|
|
record->key + 1, premaster,
|
|
/*point:*/ tls->hsd->ecc_pub_key32
|
|
);
|
|
len = CURVE25519_KEYSIZE;
|
|
//record->key[0] = len;
|
|
//len++;
|
|
//premaster_size = CURVE25519_KEYSIZE;
|
|
} else {
|
|
/* ECDHE, curve P256 */
|
|
dbg("computing P256_premaster\n");
|
|
curve_P256_compute_pubkey_and_premaster(
|
|
record->key + 2, premaster,
|
|
/*point:*/ tls->hsd->ecc_pub_key32
|
|
);
|
|
record->key[1] = 4; /* "uncompressed point" */
|
|
len = 1 + P256_KEYSIZE * 2;
|
|
}
|
|
record->key[0] = len;
|
|
len++;
|
|
premaster_size = P256_KEYSIZE; // = CURVE25519_KEYSIZE = 32
|
|
}
|
|
|
|
record->type = HANDSHAKE_CLIENT_KEY_EXCHANGE;
|
|
/* record->len24_hi = 0; - already is */
|
|
record->len24_mid = len >> 8;
|
|
record->len24_lo = len & 0xff;
|
|
len += 4;
|
|
|
|
dbg(">> CLIENT_KEY_EXCHANGE\n");
|
|
xwrite_and_update_handshake_hash(tls, len);
|
|
|
|
// RFC 5246
|
|
// For all key exchange methods, the same algorithm is used to convert
|
|
// the pre_master_secret into the master_secret. The pre_master_secret
|
|
// should be deleted from memory once the master_secret has been
|
|
// computed.
|
|
// master_secret = PRF(pre_master_secret, "master secret",
|
|
// ClientHello.random + ServerHello.random)
|
|
// [0..47];
|
|
// The master secret is always exactly 48 bytes in length. The length
|
|
// of the premaster secret will vary depending on key exchange method.
|
|
prf_hmac_sha256(/*tls,*/
|
|
tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
|
|
premaster, premaster_size,
|
|
"master secret",
|
|
tls->hsd->client_and_server_rand32, sizeof(tls->hsd->client_and_server_rand32)
|
|
);
|
|
dump_hex("master secret:%s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
|
|
|
|
// RFC 5246
|
|
// 6.3. Key Calculation
|
|
//
|
|
// The Record Protocol requires an algorithm to generate keys required
|
|
// by the current connection state (see Appendix A.6) from the security
|
|
// parameters provided by the handshake protocol.
|
|
//
|
|
// The master secret is expanded into a sequence of secure bytes, which
|
|
// is then split to a client write MAC key, a server write MAC key, a
|
|
// client write encryption key, and a server write encryption key. Each
|
|
// of these is generated from the byte sequence in that order. Unused
|
|
// values are empty. Some AEAD ciphers may additionally require a
|
|
// client write IV and a server write IV (see Section 6.2.3.3).
|
|
//
|
|
// When keys and MAC keys are generated, the master secret is used as an
|
|
// entropy source.
|
|
//
|
|
// To generate the key material, compute
|
|
//
|
|
// key_block = PRF(SecurityParameters.master_secret,
|
|
// "key expansion",
|
|
// SecurityParameters.server_random +
|
|
// SecurityParameters.client_random);
|
|
//
|
|
// until enough output has been generated. Then, the key_block is
|
|
// partitioned as follows:
|
|
//
|
|
// client_write_MAC_key[SecurityParameters.mac_key_length]
|
|
// server_write_MAC_key[SecurityParameters.mac_key_length]
|
|
// client_write_key[SecurityParameters.enc_key_length]
|
|
// server_write_key[SecurityParameters.enc_key_length]
|
|
// client_write_IV[SecurityParameters.fixed_iv_length]
|
|
// server_write_IV[SecurityParameters.fixed_iv_length]
|
|
{
|
|
uint8_t tmp64[64];
|
|
|
|
/* make "server_rand32 + client_rand32" */
|
|
memcpy(&tmp64[0] , &tls->hsd->client_and_server_rand32[32], 32);
|
|
memcpy(&tmp64[32], &tls->hsd->client_and_server_rand32[0] , 32);
|
|
|
|
prf_hmac_sha256(/*tls,*/
|
|
tls->client_write_MAC_key, 2 * (tls->MAC_size + tls->key_size + tls->IV_size),
|
|
// also fills:
|
|
// server_write_MAC_key[]
|
|
// client_write_key[]
|
|
// server_write_key[]
|
|
// client_write_IV[]
|
|
// server_write_IV[]
|
|
tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
|
|
"key expansion",
|
|
tmp64, 64
|
|
);
|
|
tls->client_write_key = tls->client_write_MAC_key + (2 * tls->MAC_size);
|
|
tls->server_write_key = tls->client_write_key + tls->key_size;
|
|
tls->client_write_IV = tls->server_write_key + tls->key_size;
|
|
tls->server_write_IV = tls->client_write_IV + tls->IV_size;
|
|
dump_hex("client_write_MAC_key:%s\n",
|
|
tls->client_write_MAC_key, tls->MAC_size
|
|
);
|
|
dump_hex("client_write_key:%s\n",
|
|
tls->client_write_key, tls->key_size
|
|
);
|
|
dump_hex("client_write_IV:%s\n",
|
|
tls->client_write_IV, tls->IV_size
|
|
);
|
|
|
|
aes_setkey(&tls->aes_decrypt, tls->server_write_key, tls->key_size);
|
|
aes_setkey(&tls->aes_encrypt, tls->client_write_key, tls->key_size);
|
|
{
|
|
uint8_t iv[AES_BLOCK_SIZE];
|
|
memset(iv, 0, AES_BLOCK_SIZE);
|
|
aes_encrypt_one_block(&tls->aes_encrypt, iv, tls->H);
|
|
}
|
|
}
|
|
}
|
|
|
|
static const uint8_t rec_CHANGE_CIPHER_SPEC[] ALIGN1 = {
|
|
RECORD_TYPE_CHANGE_CIPHER_SPEC, TLS_MAJ, TLS_MIN, 00, 01,
|
|
01
|
|
};
|
|
|
|
static void send_change_cipher_spec(tls_state_t *tls)
|
|
{
|
|
dbg(">> CHANGE_CIPHER_SPEC\n");
|
|
xwrite(tls->ofd, rec_CHANGE_CIPHER_SPEC, sizeof(rec_CHANGE_CIPHER_SPEC));
|
|
}
|
|
|
|
// 7.4.9. Finished
|
|
// A Finished message is always sent immediately after a change
|
|
// cipher spec message to verify that the key exchange and
|
|
// authentication processes were successful. It is essential that a
|
|
// change cipher spec message be received between the other handshake
|
|
// messages and the Finished message.
|
|
//...
|
|
// The Finished message is the first one protected with the just
|
|
// negotiated algorithms, keys, and secrets. Recipients of Finished
|
|
// messages MUST verify that the contents are correct. Once a side
|
|
// has sent its Finished message and received and validated the
|
|
// Finished message from its peer, it may begin to send and receive
|
|
// application data over the connection.
|
|
//...
|
|
// struct {
|
|
// opaque verify_data[verify_data_length];
|
|
// } Finished;
|
|
//
|
|
// verify_data
|
|
// PRF(master_secret, finished_label, Hash(handshake_messages))
|
|
// [0..verify_data_length-1];
|
|
//
|
|
// finished_label
|
|
// For Finished messages sent by the client, the string
|
|
// "client finished". For Finished messages sent by the server,
|
|
// the string "server finished".
|
|
//
|
|
// Hash denotes a Hash of the handshake messages. For the PRF
|
|
// defined in Section 5, the Hash MUST be the Hash used as the basis
|
|
// for the PRF. Any cipher suite which defines a different PRF MUST
|
|
// also define the Hash to use in the Finished computation.
|
|
//
|
|
// In previous versions of TLS, the verify_data was always 12 octets
|
|
// long. In the current version of TLS, it depends on the cipher
|
|
// suite. Any cipher suite which does not explicitly specify
|
|
// verify_data_length has a verify_data_length equal to 12. This
|
|
// includes all existing cipher suites.
|
|
static void send_client_finished(tls_state_t *tls)
|
|
{
|
|
struct finished {
|
|
uint8_t type;
|
|
uint8_t len24_hi, len24_mid, len24_lo;
|
|
uint8_t prf_result[12];
|
|
};
|
|
struct finished *record = tls_get_outbuf(tls, sizeof(*record));
|
|
uint8_t handshake_hash[TLS_MAX_MAC_SIZE];
|
|
unsigned len;
|
|
|
|
fill_handshake_record_hdr(record, HANDSHAKE_FINISHED, sizeof(*record));
|
|
|
|
len = sha_end(&tls->hsd->handshake_hash_ctx, handshake_hash);
|
|
|
|
prf_hmac_sha256(/*tls,*/
|
|
record->prf_result, sizeof(record->prf_result),
|
|
tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
|
|
"client finished",
|
|
handshake_hash, len
|
|
);
|
|
dump_hex("from secret: %s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
|
|
dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1);
|
|
dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
|
|
dump_hex("=> digest: %s\n", record->prf_result, sizeof(record->prf_result));
|
|
|
|
dbg(">> FINISHED\n");
|
|
xwrite_encrypted(tls, sizeof(*record), RECORD_TYPE_HANDSHAKE);
|
|
}
|
|
|
|
void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni)
|
|
{
|
|
// Client RFC 5246 Server
|
|
// (*) - optional messages, not always sent
|
|
//
|
|
// ClientHello ------->
|
|
// ServerHello
|
|
// Certificate*
|
|
// ServerKeyExchange*
|
|
// CertificateRequest*
|
|
// <------- ServerHelloDone
|
|
// Certificate*
|
|
// ClientKeyExchange
|
|
// CertificateVerify*
|
|
// [ChangeCipherSpec]
|
|
// Finished ------->
|
|
// [ChangeCipherSpec]
|
|
// <------- Finished
|
|
// Application Data <------> Application Data
|
|
int len;
|
|
int got_cert_req;
|
|
|
|
send_client_hello_and_alloc_hsd(tls, sni);
|
|
get_server_hello(tls);
|
|
|
|
// RFC 5246
|
|
// The server MUST send a Certificate message whenever the agreed-
|
|
// upon key exchange method uses certificates for authentication
|
|
// (this includes all key exchange methods defined in this document
|
|
// except DH_anon). This message will always immediately follow the
|
|
// ServerHello message.
|
|
//
|
|
// IOW: in practice, Certificate *always* follows.
|
|
// (for example, kernel.org does not even accept DH_anon cipher id)
|
|
get_server_cert(tls);
|
|
|
|
len = tls_xread_handshake_block(tls, 4);
|
|
if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_SERVER_KEY_EXCHANGE) {
|
|
// 459 bytes:
|
|
// 0c 00|01|c7 03|00|17|41|04|87|94|2e|2f|68|d0|c9|f4|97|a8|2d|ef|ed|67|ea|c6|f3|b3|56|47|5d|27|b6|bd|ee|70|25|30|5e|b0|8e|f6|21|5a...
|
|
//SvKey len=455^
|
|
// with TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: 461 bytes:
|
|
// 0c 00|01|c9 03|00|17|41|04|cd|9b|b4|29|1f|f6|b0|c2|84|82|7f|29|6a|47|4e|ec|87|0b|c1|9c|69|e1|f8|c6|d0|53|e9|27|90|a5|c8|02|15|75...
|
|
//
|
|
// RFC 8422 5.4. Server Key Exchange
|
|
// This message is sent when using the ECDHE_ECDSA, ECDHE_RSA, and
|
|
// ECDH_anon key exchange algorithms.
|
|
// This message is used to convey the server's ephemeral ECDH public key
|
|
// (and the corresponding elliptic curve domain parameters) to the
|
|
// client.
|
|
dbg("<< SERVER_KEY_EXCHANGE len:%u\n", len);
|
|
dump_raw_in("<< %s\n", tls->inbuf, RECHDR_LEN + len);
|
|
if (tls->flags & NEED_EC_KEY)
|
|
process_server_key(tls, len);
|
|
|
|
// read next handshake block
|
|
len = tls_xread_handshake_block(tls, 4);
|
|
}
|
|
|
|
got_cert_req = (tls->inbuf[RECHDR_LEN] == HANDSHAKE_CERTIFICATE_REQUEST);
|
|
if (got_cert_req) {
|
|
dbg("<< CERTIFICATE_REQUEST\n");
|
|
// RFC 5246: "If no suitable certificate is available,
|
|
// the client MUST send a certificate message containing no
|
|
// certificates. That is, the certificate_list structure has a
|
|
// length of zero. ...
|
|
// Client certificates are sent using the Certificate structure
|
|
// defined in Section 7.4.2."
|
|
// (i.e. the same format as server certs)
|
|
|
|
/*send_empty_client_cert(tls); - WRONG (breaks handshake hash calc) */
|
|
/* need to hash _all_ server replies first, up to ServerHelloDone */
|
|
len = tls_xread_handshake_block(tls, 4);
|
|
}
|
|
|
|
if (tls->inbuf[RECHDR_LEN] != HANDSHAKE_SERVER_HELLO_DONE) {
|
|
bad_record_die(tls, "'server hello done'", len);
|
|
}
|
|
// 0e 000000 (len:0)
|
|
dbg("<< SERVER_HELLO_DONE\n");
|
|
|
|
if (got_cert_req)
|
|
send_empty_client_cert(tls);
|
|
|
|
send_client_key_exchange(tls);
|
|
|
|
send_change_cipher_spec(tls);
|
|
/* from now on we should send encrypted */
|
|
/* tls->write_seq64_be = 0; - already is */
|
|
tls->flags |= ENCRYPT_ON_WRITE;
|
|
|
|
send_client_finished(tls);
|
|
|
|
/* Get CHANGE_CIPHER_SPEC */
|
|
len = tls_xread_record(tls, "switch to encrypted traffic");
|
|
if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0)
|
|
bad_record_die(tls, "switch to encrypted traffic", len);
|
|
dbg("<< CHANGE_CIPHER_SPEC\n");
|
|
|
|
if (ALLOW_RSA_NULL_SHA256
|
|
&& tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
|
|
) {
|
|
tls->min_encrypted_len_on_read = tls->MAC_size;
|
|
} else
|
|
if (!(tls->flags & ENCRYPTION_AESGCM)) {
|
|
unsigned mac_blocks = (unsigned)(TLS_MAC_SIZE(tls) + AES_BLOCK_SIZE-1) / AES_BLOCK_SIZE;
|
|
/* all incoming packets now should be encrypted and have
|
|
* at least IV + (MAC padded to blocksize):
|
|
*/
|
|
tls->min_encrypted_len_on_read = AES_BLOCK_SIZE + (mac_blocks * AES_BLOCK_SIZE);
|
|
} else {
|
|
tls->min_encrypted_len_on_read = 8 + AES_BLOCK_SIZE;
|
|
}
|
|
dbg("min_encrypted_len_on_read: %u\n", tls->min_encrypted_len_on_read);
|
|
|
|
/* Get (encrypted) FINISHED from the server */
|
|
len = tls_xread_record(tls, "'server finished'");
|
|
if (len < 4 || tls->inbuf[RECHDR_LEN] != HANDSHAKE_FINISHED)
|
|
bad_record_die(tls, "'server finished'", len);
|
|
dbg("<< FINISHED\n");
|
|
/* application data can be sent/received */
|
|
|
|
/* free handshake data */
|
|
psRsaKey_clear(&tls->hsd->server_rsa_pub_key);
|
|
// if (PARANOIA)
|
|
// memset(tls->hsd, 0, tls->hsd->hsd_size);
|
|
free(tls->hsd);
|
|
tls->hsd = NULL;
|
|
}
|
|
|
|
static void tls_xwrite(tls_state_t *tls, int len)
|
|
{
|
|
dbg(">> DATA\n");
|
|
xwrite_encrypted(tls, len, RECORD_TYPE_APPLICATION_DATA);
|
|
}
|
|
|
|
// To run a test server using openssl:
|
|
// openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
|
|
// openssl s_server -key key.pem -cert server.pem -debug -tls1_2
|
|
//
|
|
// Unencryped SHA256 example:
|
|
// openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
|
|
// openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -cipher NULL
|
|
// openssl s_client -connect 127.0.0.1:4433 -debug -tls1_2 -cipher NULL-SHA256
|
|
|
|
void FAST_FUNC tls_run_copy_loop(tls_state_t *tls, unsigned flags)
|
|
{
|
|
int inbuf_size;
|
|
const int INBUF_STEP = 4 * 1024;
|
|
struct pollfd pfds[2];
|
|
|
|
#if 0
|
|
// Debug aid for comparing P256 implementations.
|
|
// Enable this, set SP_DEBUG and FIXED_SECRET to 1,
|
|
// and add
|
|
// tls_run_copy_loop(NULL, 0);
|
|
// e.g. at the very beginning of wget_main()
|
|
//
|
|
{
|
|
uint8_t ecc_pub_key32[2 * 32];
|
|
uint8_t pubkey2x32[2 * 32];
|
|
uint8_t premaster32[32];
|
|
|
|
//Fixed input key:
|
|
// memset(ecc_pub_key32, 0xee, sizeof(ecc_pub_key32));
|
|
//Fixed 000000000000000000000000000000000000ab000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
|
|
// memset(ecc_pub_key32, 0x00, sizeof(ecc_pub_key32));
|
|
// ecc_pub_key32[18] = 0xab;
|
|
//Random key:
|
|
// tls_get_random(ecc_pub_key32, sizeof(ecc_pub_key32));
|
|
//Biased random (almost all zeros or almost all ones):
|
|
srand(time(NULL) ^ getpid());
|
|
if (rand() & 1)
|
|
memset(ecc_pub_key32, 0x00, sizeof(ecc_pub_key32));
|
|
else
|
|
memset(ecc_pub_key32, 0xff, sizeof(ecc_pub_key32));
|
|
ecc_pub_key32[rand() & 0x3f] = rand();
|
|
|
|
xmove_fd(xopen("p256.OLD", O_WRONLY | O_CREAT | O_TRUNC), 2);
|
|
curve_P256_compute_pubkey_and_premaster(
|
|
pubkey2x32, premaster32,
|
|
/*point:*/ ecc_pub_key32
|
|
);
|
|
xmove_fd(xopen("p256.NEW", O_WRONLY | O_CREAT | O_TRUNC), 2);
|
|
curve_P256_compute_pubkey_and_premaster_NEW(
|
|
pubkey2x32, premaster32,
|
|
/*point:*/ ecc_pub_key32
|
|
);
|
|
exit(1);
|
|
}
|
|
#endif
|
|
|
|
pfds[0].fd = STDIN_FILENO;
|
|
pfds[0].events = POLLIN;
|
|
pfds[1].fd = tls->ifd;
|
|
pfds[1].events = POLLIN;
|
|
|
|
inbuf_size = INBUF_STEP;
|
|
for (;;) {
|
|
int nread;
|
|
|
|
if (safe_poll(pfds, 2, -1) < 0)
|
|
bb_simple_perror_msg_and_die("poll");
|
|
|
|
if (pfds[0].revents) {
|
|
void *buf;
|
|
|
|
dbg("STDIN HAS DATA\n");
|
|
buf = tls_get_outbuf(tls, inbuf_size);
|
|
nread = safe_read(STDIN_FILENO, buf, inbuf_size);
|
|
if (nread < 1) {
|
|
/* We'd want to do this: */
|
|
/* Close outgoing half-connection so they get EOF,
|
|
* but leave incoming alone so we can see response
|
|
*/
|
|
//shutdown(tls->ofd, SHUT_WR);
|
|
/* But TLS has no way to encode this,
|
|
* doubt it's ok to do it "raw"
|
|
*/
|
|
pfds[0].fd = -1;
|
|
tls_free_outbuf(tls); /* mem usage optimization */
|
|
if (flags & TLSLOOP_EXIT_ON_LOCAL_EOF)
|
|
break;
|
|
} else {
|
|
if (nread == inbuf_size) {
|
|
/* TLS has per record overhead, if input comes fast,
|
|
* read, encrypt and send bigger chunks
|
|
*/
|
|
inbuf_size += INBUF_STEP;
|
|
if (inbuf_size > TLS_MAX_OUTBUF)
|
|
inbuf_size = TLS_MAX_OUTBUF;
|
|
}
|
|
tls_xwrite(tls, nread);
|
|
}
|
|
}
|
|
if (pfds[1].revents) {
|
|
dbg("NETWORK HAS DATA\n");
|
|
read_record:
|
|
nread = tls_xread_record(tls, "encrypted data");
|
|
if (nread < 1) {
|
|
/* TLS protocol has no real concept of one-sided shutdowns:
|
|
* if we get "TLS EOF" from the peer, writes will fail too
|
|
*/
|
|
//pfds[1].fd = -1;
|
|
//close(STDOUT_FILENO);
|
|
//tls_free_inbuf(tls); /* mem usage optimization */
|
|
//continue;
|
|
break;
|
|
}
|
|
if (tls->inbuf[0] != RECORD_TYPE_APPLICATION_DATA)
|
|
bad_record_die(tls, "encrypted data", nread);
|
|
xwrite(STDOUT_FILENO, tls->inbuf + RECHDR_LEN, nread);
|
|
/* We may already have a complete next record buffered,
|
|
* can process it without network reads (and possible blocking)
|
|
*/
|
|
if (tls_has_buffered_record(tls))
|
|
goto read_record;
|
|
}
|
|
}
|
|
}
|