mirror of
git://anongit.mindrot.org/openssh.git
synced 2024-12-18 09:44:20 +08:00
- markus@cvs.openbsd.org 2002/03/14 16:56:33
[auth-rh-rsa.c auth-rsa.c auth.h]
split auth_rsa() for better readability and privsep; ok provos@
This commit is contained in:
Ben Lindstrom
parent
abcb145b38
commit
9c8aefe750
@ -15,6 +15,9 @@
|
||||
- markus@cvs.openbsd.org 2002/03/14 16:38:26
|
||||
[sshd.c]
|
||||
split out ssh1 session key decryption; ok provos@
|
||||
- markus@cvs.openbsd.org 2002/03/14 16:56:33
|
||||
[auth-rh-rsa.c auth-rsa.c auth.h]
|
||||
split auth_rsa() for better readability and privsep; ok provos@
|
||||
|
||||
20020317
|
||||
- (tim) [configure.ac] Assume path given with --with-pid-dir=PATH is wanted,
|
||||
@ -7861,4 +7864,4 @@
|
||||
- Wrote replacements for strlcpy and mkdtemp
|
||||
- Released 1.0pre1
|
||||
|
||||
$Id: ChangeLog,v 1.1928 2002/03/22 01:10:21 mouring Exp $
|
||||
$Id: ChangeLog,v 1.1929 2002/03/22 01:12:58 mouring Exp $
|
||||
|
||||
@ -13,7 +13,7 @@
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
RCSID("$OpenBSD: auth-rh-rsa.c,v 1.29 2002/03/04 12:43:06 markus Exp $");
|
||||
RCSID("$OpenBSD: auth-rh-rsa.c,v 1.30 2002/03/14 16:56:33 markus Exp $");
|
||||
|
||||
#include "packet.h"
|
||||
#include "uidswap.h"
|
||||
@ -63,7 +63,7 @@ auth_rhosts_rsa(struct passwd *pw, const char *client_user, Key *client_host_key
|
||||
/* A matching host key was found and is known. */
|
||||
|
||||
/* Perform the challenge-response dialog with the client for the host key. */
|
||||
if (!auth_rsa_challenge_dialog(client_host_key->rsa)) {
|
||||
if (!auth_rsa_challenge_dialog(client_host_key)) {
|
||||
log("Client on %.800s failed to respond correctly to host authentication.",
|
||||
canonical_hostname);
|
||||
return 0;
|
||||
|
||||
204
auth-rsa.c
204
auth-rsa.c
@ -14,7 +14,7 @@
|
||||
*/
|
||||
|
||||
#include "includes.h"
|
||||
RCSID("$OpenBSD: auth-rsa.c,v 1.50 2001/12/28 14:50:54 markus Exp $");
|
||||
RCSID("$OpenBSD: auth-rsa.c,v 1.51 2002/03/14 16:56:33 markus Exp $");
|
||||
|
||||
#include <openssl/rsa.h>
|
||||
#include <openssl/md5.h>
|
||||
@ -52,6 +52,51 @@ extern u_char session_id[16];
|
||||
* description of the options.
|
||||
*/
|
||||
|
||||
static BIGNUM *
|
||||
auth_rsa_generate_challenge(Key *key)
|
||||
{
|
||||
BIGNUM *challenge;
|
||||
BN_CTX *ctx;
|
||||
|
||||
if ((challenge = BN_new()) == NULL)
|
||||
fatal("auth_rsa_generate_challenge: BN_new() failed");
|
||||
/* Generate a random challenge. */
|
||||
BN_rand(challenge, 256, 0, 0);
|
||||
if ((ctx = BN_CTX_new()) == NULL)
|
||||
fatal("auth_rsa_generate_challenge: BN_CTX_new() failed");
|
||||
BN_mod(challenge, challenge, key->rsa->n, ctx);
|
||||
BN_CTX_free(ctx);
|
||||
|
||||
return challenge;
|
||||
}
|
||||
|
||||
static int
|
||||
auth_rsa_verify_response(Key *key, BIGNUM *challenge, u_char response[16])
|
||||
{
|
||||
u_char buf[32], mdbuf[16];
|
||||
MD5_CTX md;
|
||||
int len;
|
||||
|
||||
/* The response is MD5 of decrypted challenge plus session id. */
|
||||
len = BN_num_bytes(challenge);
|
||||
if (len <= 0 || len > 32)
|
||||
fatal("auth_rsa_verify_response: bad challenge length %d", len);
|
||||
memset(buf, 0, 32);
|
||||
BN_bn2bin(challenge, buf + 32 - len);
|
||||
MD5_Init(&md);
|
||||
MD5_Update(&md, buf, 32);
|
||||
MD5_Update(&md, session_id, 16);
|
||||
MD5_Final(mdbuf, &md);
|
||||
|
||||
/* Verify that the response is the original challenge. */
|
||||
if (memcmp(response, mdbuf, 16) != 0) {
|
||||
/* Wrong answer. */
|
||||
return (0);
|
||||
}
|
||||
/* Correct answer. */
|
||||
return (1);
|
||||
}
|
||||
|
||||
/*
|
||||
* Performs the RSA authentication challenge-response dialog with the client,
|
||||
* and returns true (non-zero) if the client gave the correct answer to
|
||||
@ -59,29 +104,19 @@ extern u_char session_id[16];
|
||||
*/
|
||||
|
||||
int
|
||||
auth_rsa_challenge_dialog(RSA *pk)
|
||||
auth_rsa_challenge_dialog(Key *key)
|
||||
{
|
||||
BIGNUM *challenge, *encrypted_challenge;
|
||||
BN_CTX *ctx;
|
||||
u_char buf[32], mdbuf[16], response[16];
|
||||
MD5_CTX md;
|
||||
u_int i;
|
||||
int len;
|
||||
u_char response[16];
|
||||
int i, success;
|
||||
|
||||
if ((encrypted_challenge = BN_new()) == NULL)
|
||||
fatal("auth_rsa_challenge_dialog: BN_new() failed");
|
||||
if ((challenge = BN_new()) == NULL)
|
||||
fatal("auth_rsa_challenge_dialog: BN_new() failed");
|
||||
|
||||
/* Generate a random challenge. */
|
||||
BN_rand(challenge, 256, 0, 0);
|
||||
if ((ctx = BN_CTX_new()) == NULL)
|
||||
fatal("auth_rsa_challenge_dialog: BN_CTX_new() failed");
|
||||
BN_mod(challenge, challenge, pk->n, ctx);
|
||||
BN_CTX_free(ctx);
|
||||
challenge = auth_rsa_generate_challenge(key);
|
||||
|
||||
/* Encrypt the challenge with the public key. */
|
||||
rsa_public_encrypt(encrypted_challenge, challenge, pk);
|
||||
rsa_public_encrypt(encrypted_challenge, challenge, key->rsa);
|
||||
|
||||
/* Send the encrypted challenge to the client. */
|
||||
packet_start(SSH_SMSG_AUTH_RSA_CHALLENGE);
|
||||
@ -96,48 +131,26 @@ auth_rsa_challenge_dialog(RSA *pk)
|
||||
response[i] = packet_get_char();
|
||||
packet_check_eom();
|
||||
|
||||
/* The response is MD5 of decrypted challenge plus session id. */
|
||||
len = BN_num_bytes(challenge);
|
||||
if (len <= 0 || len > 32)
|
||||
fatal("auth_rsa_challenge_dialog: bad challenge length %d", len);
|
||||
memset(buf, 0, 32);
|
||||
BN_bn2bin(challenge, buf + 32 - len);
|
||||
MD5_Init(&md);
|
||||
MD5_Update(&md, buf, 32);
|
||||
MD5_Update(&md, session_id, 16);
|
||||
MD5_Final(mdbuf, &md);
|
||||
success = auth_rsa_verify_response(key, challenge, response);
|
||||
BN_clear_free(challenge);
|
||||
|
||||
/* Verify that the response is the original challenge. */
|
||||
if (memcmp(response, mdbuf, 16) != 0) {
|
||||
/* Wrong answer. */
|
||||
return 0;
|
||||
}
|
||||
/* Correct answer. */
|
||||
return 1;
|
||||
return (success);
|
||||
}
|
||||
|
||||
/*
|
||||
* Performs the RSA authentication dialog with the client. This returns
|
||||
* 0 if the client could not be authenticated, and 1 if authentication was
|
||||
* successful. This may exit if there is a serious protocol violation.
|
||||
* check if there's user key matching client_n,
|
||||
* return key if login is allowed, NULL otherwise
|
||||
*/
|
||||
|
||||
int
|
||||
auth_rsa(struct passwd *pw, BIGNUM *client_n)
|
||||
static int
|
||||
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
|
||||
{
|
||||
char line[8192], *file;
|
||||
int authenticated;
|
||||
int allowed;
|
||||
u_int bits;
|
||||
FILE *f;
|
||||
u_long linenum = 0;
|
||||
struct stat st;
|
||||
Key *key;
|
||||
char *fp;
|
||||
|
||||
/* no user given */
|
||||
if (pw == NULL)
|
||||
return 0;
|
||||
|
||||
/* Temporarily use the user's uid. */
|
||||
temporarily_use_uid(pw);
|
||||
@ -151,29 +164,27 @@ auth_rsa(struct passwd *pw, BIGNUM *client_n)
|
||||
/* Restore the privileged uid. */
|
||||
restore_uid();
|
||||
xfree(file);
|
||||
return 0;
|
||||
return (NULL);
|
||||
}
|
||||
/* Open the file containing the authorized keys. */
|
||||
f = fopen(file, "r");
|
||||
if (!f) {
|
||||
/* Restore the privileged uid. */
|
||||
restore_uid();
|
||||
packet_send_debug("Could not open %.900s for reading.", file);
|
||||
packet_send_debug("If your home is on an NFS volume, it may need to be world-readable.");
|
||||
xfree(file);
|
||||
return 0;
|
||||
return (NULL);
|
||||
}
|
||||
if (options.strict_modes &&
|
||||
secure_filename(f, file, pw, line, sizeof(line)) != 0) {
|
||||
xfree(file);
|
||||
fclose(f);
|
||||
log("Authentication refused: %s", line);
|
||||
packet_send_debug("Authentication refused: %s", line);
|
||||
restore_uid();
|
||||
return 0;
|
||||
return (NULL);
|
||||
}
|
||||
/* Flag indicating whether authentication has succeeded. */
|
||||
authenticated = 0;
|
||||
|
||||
/* Flag indicating whether the key is allowed. */
|
||||
allowed = 0;
|
||||
|
||||
key = key_new(KEY_RSA1);
|
||||
|
||||
@ -238,32 +249,8 @@ auth_rsa(struct passwd *pw, BIGNUM *client_n)
|
||||
if (!auth_parse_options(pw, options, file, linenum))
|
||||
continue;
|
||||
|
||||
/* Perform the challenge-response dialog for this key. */
|
||||
if (!auth_rsa_challenge_dialog(key->rsa)) {
|
||||
/* Wrong response. */
|
||||
verbose("Wrong response to RSA authentication challenge.");
|
||||
packet_send_debug("Wrong response to RSA authentication challenge.");
|
||||
/*
|
||||
* Break out of the loop. Otherwise we might send
|
||||
* another challenge and break the protocol.
|
||||
*/
|
||||
break;
|
||||
}
|
||||
/*
|
||||
* Correct response. The client has been successfully
|
||||
* authenticated. Note that we have not yet processed the
|
||||
* options; this will be reset if the options cause the
|
||||
* authentication to be rejected.
|
||||
* Break out of the loop if authentication was successful;
|
||||
* otherwise continue searching.
|
||||
*/
|
||||
authenticated = 1;
|
||||
|
||||
fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
|
||||
verbose("Found matching %s key: %s",
|
||||
key_type(key), fp);
|
||||
xfree(fp);
|
||||
|
||||
/* break out, this key is allowed */
|
||||
allowed = 1;
|
||||
break;
|
||||
}
|
||||
|
||||
@ -274,13 +261,58 @@ auth_rsa(struct passwd *pw, BIGNUM *client_n)
|
||||
xfree(file);
|
||||
fclose(f);
|
||||
|
||||
/* return key if allowed */
|
||||
if (allowed && rkey != NULL)
|
||||
*rkey = key;
|
||||
else
|
||||
key_free(key);
|
||||
return (allowed);
|
||||
}
|
||||
|
||||
/*
|
||||
* Performs the RSA authentication dialog with the client. This returns
|
||||
* 0 if the client could not be authenticated, and 1 if authentication was
|
||||
* successful. This may exit if there is a serious protocol violation.
|
||||
*/
|
||||
int
|
||||
auth_rsa(struct passwd *pw, BIGNUM *client_n)
|
||||
{
|
||||
Key *key;
|
||||
char *fp;
|
||||
|
||||
/* no user given */
|
||||
if (pw == NULL)
|
||||
return 0;
|
||||
|
||||
if (auth_rsa_key_allowed(pw, client_n, &key) == 0) {
|
||||
auth_clear_options();
|
||||
return (0);
|
||||
}
|
||||
|
||||
/* Perform the challenge-response dialog for this key. */
|
||||
if (!auth_rsa_challenge_dialog(key)) {
|
||||
/* Wrong response. */
|
||||
verbose("Wrong response to RSA authentication challenge.");
|
||||
packet_send_debug("Wrong response to RSA authentication challenge.");
|
||||
/*
|
||||
* Break out of the loop. Otherwise we might send
|
||||
* another challenge and break the protocol.
|
||||
*/
|
||||
key_free(key);
|
||||
return (0);
|
||||
}
|
||||
/*
|
||||
* Correct response. The client has been successfully
|
||||
* authenticated. Note that we have not yet processed the
|
||||
* options; this will be reset if the options cause the
|
||||
* authentication to be rejected.
|
||||
*/
|
||||
fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
|
||||
verbose("Found matching %s key: %s",
|
||||
key_type(key), fp);
|
||||
xfree(fp);
|
||||
key_free(key);
|
||||
|
||||
if (authenticated)
|
||||
packet_send_debug("RSA authentication accepted.");
|
||||
else
|
||||
auth_clear_options();
|
||||
|
||||
/* Return authentication result. */
|
||||
return authenticated;
|
||||
packet_send_debug("RSA authentication accepted.");
|
||||
return (1);
|
||||
}
|
||||
|
||||
4
auth.h
4
auth.h
@ -1,4 +1,4 @@
|
||||
/* $OpenBSD: auth.h,v 1.29 2002/03/04 17:27:39 stevesk Exp $ */
|
||||
/* $OpenBSD: auth.h,v 1.30 2002/03/14 16:56:33 markus Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 2000 Markus Friedl. All rights reserved.
|
||||
@ -95,7 +95,7 @@ auth_rhosts2(struct passwd *, const char *, const char *, const char *);
|
||||
int auth_rhosts_rsa(struct passwd *, const char *, Key *);
|
||||
int auth_password(Authctxt *, const char *);
|
||||
int auth_rsa(struct passwd *, BIGNUM *);
|
||||
int auth_rsa_challenge_dialog(RSA *);
|
||||
int auth_rsa_challenge_dialog(Key *);
|
||||
|
||||
#ifdef KRB4
|
||||
#include <krb.h>
|
||||
|
||||
Loading…
Reference in New Issue
Block a user