/* crypto/rsa/rsa_sign.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/bn.h>
#include <openssl/rsa.h>
#include <openssl/objects.h>
#include <openssl/x509.h>
#include "rsa_locl.h"
/* Size of an SSL signature: MD5+SHA1 */
#define SSL_SIG_LENGTH 36
int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
unsigned char *sigret, unsigned int *siglen, RSA *rsa)
{
X509_SIG sig;
ASN1_TYPE parameter;
int i,j,ret=1;
unsigned char *p, *tmps = NULL;
const unsigned char *s = NULL;
X509_ALGOR algor;
ASN1_OCTET_STRING digest;
#ifdef OPENSSL_FIPS
if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
&& !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
{
RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD);
return 0;
}
#endif
if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign)
{
return rsa->meth->rsa_sign(type, m, m_len,
sigret, siglen, rsa);
}
/* Special case: SSL signature, just check the length */
if(type == NID_md5_sha1) {
if(m_len != SSL_SIG_LENGTH) {
RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);
return(0);
}
i = SSL_SIG_LENGTH;
s = m;
} else {
sig.algor= &algor;
sig.algor->algorithm=OBJ_nid2obj(type);
if (sig.algor->algorithm == NULL)
{
RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);
return(0);
}
if (sig.algor->algorithm->length == 0)
{
RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
return(0);
}
parameter.type=V_ASN1_NULL;
parameter.value.ptr=NULL;
sig.algor->parameter= ¶meter;
sig.digest= &digest;
sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */
sig.digest->length=m_len;
i=i2d_X509_SIG(&sig,NULL);
}
j=RSA_size(rsa);
if (i > (j-RSA_PKCS1_PADDING_SIZE))
{
RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
return(0);
}
if(type != NID_md5_sha1) {
tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);
if (tmps == NULL)
{
RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);
return(0);
}
p=tmps;
i2d_X509_SIG(&sig,&p);
s=tmps;
}
i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);
if (i <= 0)
ret=0;
else
*siglen=i;
if(type != NID_md5_sha1) {
OPENSSL_cleanse(tmps,(unsigned int)j+1);
OPENSSL_free(tmps);
}
return(ret);
}
int int_rsa_verify(int dtype, const unsigned char *m,
unsigned int m_len,
unsigned char *rm, size_t *prm_len,
const unsigned char *sigbuf, size_t siglen,
RSA *rsa)
{
int i,ret=0,sigtype;
unsigned char *s;
X509_SIG *sig=NULL;
#ifdef OPENSSL_FIPS
if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
&& !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
{
RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD);
return 0;
}
#endif
if (siglen != (unsigned int)RSA_size(rsa))
{
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
return(0);
}
if((dtype == NID_md5_sha1) && rm)
{
i = RSA_public_decrypt((int)siglen,
sigbuf,rm,rsa,RSA_PKCS1_PADDING);
if (i <= 0)
return 0;
*prm_len = i;
return 1;
}
s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
if (s == NULL)
{
RSAerr(RSA_F_INT_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
goto err;
}
if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
goto err;
}
i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
if (i <= 0) goto err;
/* Oddball MDC2 case: signature can be OCTET STRING.
* check for correct tag and length octets.
*/
if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10)
{
if (rm)
{
memcpy(rm, s + 2, 16);
*prm_len = 16;
ret = 1;
}
else if(memcmp(m, s + 2, 16))
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
else
ret = 1;
}
/* Special case: SSL signature */
if(dtype == NID_md5_sha1) {
if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
else ret = 1;
} else {
const unsigned char *p=s;
sig=d2i_X509_SIG(NULL,&p,(long)i);
if (sig == NULL) goto err;
/* Excess data can be used to create forgeries */
if(p != s+i)
{
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
goto err;
}
/* Parameters to the signature algorithm can also be used to
create forgeries */
if(sig->algor->parameter
&& ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)
{
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
goto err;
}
sigtype=OBJ_obj2nid(sig->algor->algorithm);
#ifdef RSA_DEBUG
/* put a backward compatibility flag in EAY */
fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
OBJ_nid2ln(dtype));
#endif
if (sigtype != dtype)
{
if (((dtype == NID_md5) &&
(sigtype == NID_md5WithRSAEncryption)) ||
((dtype == NID_md2) &&
(sigtype == NID_md2WithRSAEncryption)))
{
/* ok, we will let it through */
#if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
#endif
}
else
{
RSAerr(RSA_F_INT_RSA_VERIFY,
RSA_R_ALGORITHM_MISMATCH);
goto err;
}
}
if (rm)
{
const EVP_MD *md;
md = EVP_get_digestbynid(dtype);
if (md && (EVP_MD_size(md) != sig->digest->length))
RSAerr(RSA_F_INT_RSA_VERIFY,
RSA_R_INVALID_DIGEST_LENGTH);
else
{
memcpy(rm, sig->digest->data,
sig->digest->length);
*prm_len = sig->digest->length;
ret = 1;
}
}
else if (((unsigned int)sig->digest->length != m_len) ||
(memcmp(m,sig->digest->data,m_len) != 0))
{
RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
}
else
ret=1;
}
err:
if (sig != NULL) X509_SIG_free(sig);
if (s != NULL)
{
OPENSSL_cleanse(s,(unsigned int)siglen);
OPENSSL_free(s);
}
return(ret);
}
int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
const unsigned char *sigbuf, unsigned int siglen,
RSA *rsa)
{
if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
{
return rsa->meth->rsa_verify(dtype, m, m_len,
sigbuf, siglen, rsa);
}
return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
}