linux/include/crypto/public_key.h
zhenwei pi f985911b7b crypto: public_key: fix overflow during implicit conversion
Hit kernel warning like this, it can be reproduced by verifying 256
bytes datafile by keyctl command, run script:
RAWDATA=rawdata
SIGDATA=sigdata

modprobe pkcs8_key_parser

rm -rf *.der *.pem *.pfx
rm -rf $RAWDATA
dd if=/dev/random of=$RAWDATA bs=256 count=1

openssl req -nodes -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem \
  -subj "/C=CN/ST=GD/L=SZ/O=vihoo/OU=dev/CN=xx.com/emailAddress=yy@xx.com"

KEY_ID=`openssl pkcs8 -in key.pem -topk8 -nocrypt -outform DER | keyctl \
  padd asymmetric 123 @s`

keyctl pkey_sign $KEY_ID 0 $RAWDATA enc=pkcs1 hash=sha1 > $SIGDATA
keyctl pkey_verify $KEY_ID 0 $RAWDATA $SIGDATA enc=pkcs1 hash=sha1

Then the kernel reports:
 WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540
   pkcs1pad_verify+0x160/0x190
 ...
 Call Trace:
  public_key_verify_signature+0x282/0x380
  ? software_key_query+0x12d/0x180
  ? keyctl_pkey_params_get+0xd6/0x130
  asymmetric_key_verify_signature+0x66/0x80
  keyctl_pkey_verify+0xa5/0x100
  do_syscall_64+0x35/0xb0
  entry_SYSCALL_64_after_hwframe+0x44/0xae

The reason of this issue, in function 'asymmetric_key_verify_signature':
'.digest_size(u8) = params->in_len(u32)' leads overflow of an u8 value,
so use u32 instead of u8 for digest_size field. And reorder struct
public_key_signature, it saves 8 bytes on a 64-bit machine.

Cc: stable@vger.kernel.org
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2021-08-23 20:25:24 +03:00

87 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Asymmetric public-key algorithm definitions
*
* See Documentation/crypto/asymmetric-keys.rst
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#ifndef _LINUX_PUBLIC_KEY_H
#define _LINUX_PUBLIC_KEY_H
#include <linux/keyctl.h>
#include <linux/oid_registry.h>
/*
* Cryptographic data for the public-key subtype of the asymmetric key type.
*
* Note that this may include private part of the key as well as the public
* part.
*/
struct public_key {
void *key;
u32 keylen;
enum OID algo;
void *params;
u32 paramlen;
bool key_is_private;
const char *id_type;
const char *pkey_algo;
};
extern void public_key_free(struct public_key *key);
/*
* Public key cryptography signature data
*/
struct public_key_signature {
struct asymmetric_key_id *auth_ids[2];
u8 *s; /* Signature */
u8 *digest;
u32 s_size; /* Number of bytes in signature */
u32 digest_size; /* Number of bytes in digest */
const char *pkey_algo;
const char *hash_algo;
const char *encoding;
const void *data;
unsigned int data_size;
};
extern void public_key_signature_free(struct public_key_signature *sig);
extern struct asymmetric_key_subtype public_key_subtype;
struct key;
struct key_type;
union key_payload;
extern int restrict_link_by_signature(struct key *dest_keyring,
const struct key_type *type,
const union key_payload *payload,
struct key *trust_keyring);
extern int restrict_link_by_key_or_keyring(struct key *dest_keyring,
const struct key_type *type,
const union key_payload *payload,
struct key *trusted);
extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
const struct key_type *type,
const union key_payload *payload,
struct key *trusted);
extern int query_asymmetric_key(const struct kernel_pkey_params *,
struct kernel_pkey_query *);
extern int encrypt_blob(struct kernel_pkey_params *, const void *, void *);
extern int decrypt_blob(struct kernel_pkey_params *, const void *, void *);
extern int create_signature(struct kernel_pkey_params *, const void *, void *);
extern int verify_signature(const struct key *,
const struct public_key_signature *);
int public_key_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig);
#endif /* _LINUX_PUBLIC_KEY_H */