release/src/router/openssl/crypto/rsa/rsa_sign.c

   1 /* crypto/rsa/rsa_sign.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include <openssl/bn.h>
  62 #include <openssl/rsa.h>
  63 #include <openssl/objects.h>
  64 #include <openssl/x509.h>
  65 #include "rsa_locl.h"
  66
  67 /* Size of an SSL signature: MD5+SHA1 */
  68 #define SSL_SIG_LENGTH  36
  69
  70 int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
  71              unsigned char *sigret, unsigned int *siglen, RSA *rsa)
  72 {
  73     X509_SIG sig;
  74     ASN1_TYPE parameter;
  75     int i, j, ret = 1;
  76     unsigned char *p, *tmps = NULL;
  77     const unsigned char *s = NULL;
  78     X509_ALGOR algor;
  79     ASN1_OCTET_STRING digest;
  80 #ifdef OPENSSL_FIPS
  81     if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
  82         && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
  83         RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD);
  84         return 0;
  85     }
  86 #endif
  87     if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) {
  88         return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa);
  89     }
  90     /* Special case: SSL signature, just check the length */
  91     if (type == NID_md5_sha1) {
  92         if (m_len != SSL_SIG_LENGTH) {
  93             RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH);
  94             return (0);
  95         }
  96         i = SSL_SIG_LENGTH;
  97         s = m;
  98     } else {
  99         sig.algor = &algor;
 100         sig.algor->algorithm = OBJ_nid2obj(type);
 101         if (sig.algor->algorithm == NULL) {
 102             RSAerr(RSA_F_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE);
 103             return (0);
 104         }
 105         if (sig.algor->algorithm->length == 0) {
 106             RSAerr(RSA_F_RSA_SIGN,
 107                    RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
 108             return (0);
 109         }
 110         parameter.type = V_ASN1_NULL;
 111         parameter.value.ptr = NULL;
 112         sig.algor->parameter = &parameter;
 113
 114         sig.digest = &digest;
 115         sig.digest->data = (unsigned char *)m; /* TMP UGLY CAST */
 116         sig.digest->length = m_len;
 117
 118         i = i2d_X509_SIG(&sig, NULL);
 119     }
 120     j = RSA_size(rsa);
 121     if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
 122         RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
 123         return (0);
 124     }
 125     if (type != NID_md5_sha1) {
 126         tmps = (unsigned char *)OPENSSL_malloc((unsigned int)j + 1);
 127         if (tmps == NULL) {
 128             RSAerr(RSA_F_RSA_SIGN, ERR_R_MALLOC_FAILURE);
 129             return (0);
 130         }
 131         p = tmps;
 132         i2d_X509_SIG(&sig, &p);
 133         s = tmps;
 134     }
 135     i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);
 136     if (i <= 0)
 137         ret = 0;
 138     else
 139         *siglen = i;
 140
 141     if (type != NID_md5_sha1) {
 142         OPENSSL_cleanse(tmps, (unsigned int)j + 1);
 143         OPENSSL_free(tmps);
 144     }
 145     return (ret);
 146 }
 147
 148 /*
 149  * Check DigestInfo structure does not contain extraneous data by reencoding
 150  * using DER and checking encoding against original.
 151  */
 152 static int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo,
 153                                 int dinfolen)
 154 {
 155     unsigned char *der = NULL;
 156     int derlen;
 157     int ret = 0;
 158     derlen = i2d_X509_SIG(sig, &der);
 159     if (derlen <= 0)
 160         return 0;
 161     if (derlen == dinfolen && !memcmp(dinfo, der, derlen))
 162         ret = 1;
 163     OPENSSL_cleanse(der, derlen);
 164     OPENSSL_free(der);
 165     return ret;
 166 }
 167
 168 int int_rsa_verify(int dtype, const unsigned char *m,
 169                    unsigned int m_len,
 170                    unsigned char *rm, size_t *prm_len,
 171                    const unsigned char *sigbuf, size_t siglen, RSA *rsa)
 172 {
 173     int i, ret = 0, sigtype;
 174     unsigned char *s;
 175     X509_SIG *sig = NULL;
 176
 177 #ifdef OPENSSL_FIPS
 178     if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
 179         && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
 180         RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD);
 181         return 0;
 182     }
 183 #endif
 184
 185     if (siglen != (unsigned int)RSA_size(rsa)) {
 186         RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH);
 187         return (0);
 188     }
 189
 190     if ((dtype == NID_md5_sha1) && rm) {
 191         i = RSA_public_decrypt((int)siglen,
 192                                sigbuf, rm, rsa, RSA_PKCS1_PADDING);
 193         if (i <= 0)
 194             return 0;
 195         *prm_len = i;
 196         return 1;
 197     }
 198
 199     s = (unsigned char *)OPENSSL_malloc((unsigned int)siglen);
 200     if (s == NULL) {
 201         RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE);
 202         goto err;
 203     }
 204     if ((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH)) {
 205         RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH);
 206         goto err;
 207     }
 208     i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING);
 209
 210     if (i <= 0)
 211         goto err;
 212     /*
 213      * Oddball MDC2 case: signature can be OCTET STRING. check for correct
 214      * tag and length octets.
 215      */
 216     if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10) {
 217         if (rm) {
 218             memcpy(rm, s + 2, 16);
 219             *prm_len = 16;
 220             ret = 1;
 221         } else if (memcmp(m, s + 2, 16))
 222             RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
 223         else
 224             ret = 1;
 225     }
 226
 227     /* Special case: SSL signature */
 228     if (dtype == NID_md5_sha1) {
 229         if ((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
 230             RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
 231         else
 232             ret = 1;
 233     } else {
 234         const unsigned char *p = s;
 235         sig = d2i_X509_SIG(NULL, &p, (long)i);
 236
 237         if (sig == NULL)
 238             goto err;
 239
 240         /* Excess data can be used to create forgeries */
 241         if (p != s + i || !rsa_check_digestinfo(sig, s, i)) {
 242             RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
 243             goto err;
 244         }
 245
 246         /*
 247          * Parameters to the signature algorithm can also be used to create
 248          * forgeries
 249          */
 250         if (sig->algor->parameter
 251             && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) {
 252             RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
 253             goto err;
 254         }
 255
 256         sigtype = OBJ_obj2nid(sig->algor->algorithm);
 257
 258 #ifdef RSA_DEBUG
 259         /* put a backward compatibility flag in EAY */
 260         fprintf(stderr, "in(%s) expect(%s)\n", OBJ_nid2ln(sigtype),
 261                 OBJ_nid2ln(dtype));
 262 #endif
 263         if (sigtype != dtype) {
 264             RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_ALGORITHM_MISMATCH);
 265             goto err;
 266         }
 267         if (rm) {
 268             const EVP_MD *md;
 269             md = EVP_get_digestbynid(dtype);
 270             if (md && (EVP_MD_size(md) != sig->digest->length))
 271                 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH);
 272             else {
 273                 memcpy(rm, sig->digest->data, sig->digest->length);
 274                 *prm_len = sig->digest->length;
 275                 ret = 1;
 276             }
 277         } else if (((unsigned int)sig->digest->length != m_len) ||
 278                    (memcmp(m, sig->digest->data, m_len) != 0)) {
 279             RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
 280         } else
 281             ret = 1;
 282     }
 283  err:
 284     if (sig != NULL)
 285         X509_SIG_free(sig);
 286     if (s != NULL) {
 287         OPENSSL_cleanse(s, (unsigned int)siglen);
 288         OPENSSL_free(s);
 289     }
 290     return (ret);
 291 }
 292
 293 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
 294                const unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
 295 {
 296
 297     if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) {
 298         return rsa->meth->rsa_verify(dtype, m, m_len, sigbuf, siglen, rsa);
 299     }
 300
 301     return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
 302 }