signature.c

00001 /* signature.c
00002  *
00003  * Copyright (C) 2006-2016 wolfSSL Inc.
00004  *
00005  * This file is part of wolfSSL.
00006  *
00007  * wolfSSL is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * wolfSSL is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with this program; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
00020  */
00021 
00022 
00023 #ifdef HAVE_CONFIG_H
00024     #include <config.h>
00025 #endif
00026 
00027 #include <wolfssl/wolfcrypt/settings.h>
00028 #include <wolfssl/wolfcrypt/signature.h>
00029 #include <wolfssl/wolfcrypt/error-crypt.h>
00030 #include <wolfssl/wolfcrypt/logging.h>
00031 #ifndef NO_ASN
00032 #include <wolfssl/wolfcrypt/asn.h>
00033 #endif
00034 #ifdef HAVE_ECC
00035 #include <wolfssl/wolfcrypt/ecc.h>
00036 #endif
00037 #ifndef NO_RSA
00038 #include <wolfssl/wolfcrypt/rsa.h>
00039 #endif
00040 
00041 /* If ECC and RSA are disabled then disable signature wrapper */
00042 #if (!defined(HAVE_ECC) || (defined(HAVE_ECC) && !defined(HAVE_ECC_SIGN) \
00043     && !defined(HAVE_ECC_VERIFY))) && defined(NO_RSA)
00044     #undef NO_SIG_WRAPPER
00045     #define NO_SIG_WRAPPER
00046 #endif
00047 
00048 /* Signature wrapper disabled check */
00049 #ifndef NO_SIG_WRAPPER
00050 
00051 #if !defined(NO_RSA) && !defined(NO_ASN)
00052 static int wc_SignatureDerEncode(enum wc_HashType hash_type, byte** hash_data,
00053     word32* hash_len)
00054 {
00055     int ret = wc_HashGetOID(hash_type);
00056     if (ret > 0) {
00057         int oid = ret;
00058 
00059         /* Allocate buffer for hash and max DER encoded */
00060         word32 digest_len = *hash_len + MAX_DER_DIGEST_SZ;
00061         byte *digest_buf = (byte*)XMALLOC(digest_len, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00062         if (digest_buf) {
00063             ret = wc_EncodeSignature(digest_buf, *hash_data, *hash_len, oid);
00064             if (ret > 0) {
00065                 digest_len = ret;
00066 
00067                 /* Replace hash with digest (DER encoding + hash) */
00068                 XFREE(*hash_data, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00069                 *hash_data = digest_buf;
00070                 *hash_len = digest_len;
00071             }
00072             else {
00073                 XFREE(digest_buf, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00074             }
00075         }
00076         else {
00077             ret = MEMORY_E;
00078         }
00079     }
00080     return ret;
00081 }
00082 #endif /* !NO_RSA && !NO_ASN */
00083 
00084 int wc_SignatureGetSize(enum wc_SignatureType sig_type,
00085     const void* key, word32 key_len)
00086 {
00087     int sig_len = BAD_FUNC_ARG;
00088 
00089     /* Suppress possible unused args if all signature types are disabled */
00090     (void)key;
00091     (void)key_len;
00092 
00093     switch(sig_type) {
00094         case WC_SIGNATURE_TYPE_ECC:
00095 #ifdef HAVE_ECC
00096             /* Santity check that void* key is at least ecc_key in size */
00097             if (key_len >= sizeof(ecc_key)) {
00098                 sig_len = wc_ecc_sig_size((ecc_key*)key);
00099             }
00100             else {
00101                 WOLFSSL_MSG("wc_SignatureGetSize: Invalid ECC key size");
00102             }
00103 #else
00104             sig_len = SIG_TYPE_E;
00105 #endif
00106             break;
00107 
00108         case WC_SIGNATURE_TYPE_RSA_W_ENC:
00109         case WC_SIGNATURE_TYPE_RSA:
00110 #ifndef NO_RSA
00111             /* Santity check that void* key is at least RsaKey in size */
00112             if (key_len >= sizeof(RsaKey)) {
00113                 sig_len = wc_RsaEncryptSize((RsaKey*)key);
00114             }
00115             else {
00116                 WOLFSSL_MSG("wc_SignatureGetSize: Invalid RsaKey key size");
00117             }
00118 #else
00119             sig_len = SIG_TYPE_E;
00120 #endif
00121             break;
00122 
00123         case WC_SIGNATURE_TYPE_NONE:
00124         default:
00125             sig_len = BAD_FUNC_ARG;
00126             break;
00127     }
00128     return sig_len;
00129 }
00130 
00131 int wc_SignatureVerify(
00132     enum wc_HashType hash_type, enum wc_SignatureType sig_type,
00133     const byte* data, word32 data_len,
00134     const byte* sig, word32 sig_len,
00135     const void* key, word32 key_len)
00136 {
00137     int ret;
00138     word32 hash_len;
00139     byte *hash_data = NULL;
00140 
00141     /* Check arguments */
00142     if (data == NULL || data_len <= 0 || sig == NULL || sig_len <= 0 ||
00143         key == NULL || key_len <= 0) {
00144         return BAD_FUNC_ARG;
00145     }
00146 
00147     /* Validate signature len (1 to max is okay) */
00148     if ((int)sig_len > wc_SignatureGetSize(sig_type, key, key_len)) {
00149         WOLFSSL_MSG("wc_SignatureVerify: Invalid sig type/len");
00150         return BAD_FUNC_ARG;
00151     }
00152 
00153     /* Validate hash size */
00154     ret = wc_HashGetDigestSize(hash_type);
00155     if (ret < 0) {
00156         WOLFSSL_MSG("wc_SignatureVerify: Invalid hash type/len");
00157         return ret;
00158     }
00159     hash_len = ret;
00160 
00161     /* Allocate temporary buffer for hash data */
00162     hash_data = (byte*)XMALLOC(hash_len, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00163     if (hash_data == NULL) {
00164         return MEMORY_E;
00165     }
00166 
00167     /* Perform hash of data */
00168     ret = wc_Hash(hash_type, data, data_len, hash_data, hash_len);
00169     if(ret == 0) {
00170         /* Verify signature using hash as data */
00171         switch(sig_type) {
00172             case WC_SIGNATURE_TYPE_ECC:
00173             {
00174 #if defined(HAVE_ECC) && defined(HAVE_ECC_VERIFY)
00175                 int is_valid_sig = 0;
00176 
00177                 /* Perform verification of signature using provided ECC key */
00178                 ret = wc_ecc_verify_hash(sig, sig_len, hash_data, hash_len, &is_valid_sig, (ecc_key*)key);
00179                 if (ret != 0 || is_valid_sig != 1) {
00180                     ret = SIG_VERIFY_E;
00181                 }
00182 #else
00183                 ret = SIG_TYPE_E;
00184 #endif
00185                 break;
00186             }
00187 
00188             case WC_SIGNATURE_TYPE_RSA_W_ENC:
00189 #if defined(NO_RSA) || defined(NO_ASN)
00190                 ret = SIG_TYPE_E;
00191                 break;
00192 #else
00193                 ret = wc_SignatureDerEncode(hash_type, &hash_data, &hash_len);
00194                 /* Check for error */
00195                 if (ret < 0) {
00196                     break;
00197                 }
00198                 /* Otherwise fall-through and perform normal RSA verify against updated
00199                  * DER encoding + hash */
00200 #endif
00201 
00202             case WC_SIGNATURE_TYPE_RSA:
00203             {
00204 #ifndef NO_RSA
00205                 word32 plain_len = hash_len;
00206                 byte *plain_data;
00207 
00208                 /* Make sure the plain text output is at least key size */
00209                 if (plain_len < sig_len) {
00210                     plain_len = sig_len;
00211                 }
00212                 plain_data = (byte*)XMALLOC(hash_len, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00213                 if (plain_data) {
00214                     /* Perform verification of signature using provided RSA key */
00215                     ret = wc_RsaSSL_Verify(sig, sig_len, plain_data, plain_len,
00216                         (RsaKey*)key);
00217                     if (ret >= 0) {
00218                         if ((word32)ret == hash_len &&
00219                                 XMEMCMP(plain_data, hash_data, hash_len) == 0) {
00220                             ret = 0; /* Success */
00221                         }
00222                         else {
00223                             WOLFSSL_MSG("RSA Signature Verify difference!");
00224                             ret = SIG_VERIFY_E;
00225                         }
00226                     }
00227                     XFREE(plain_data, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00228                 }
00229                 else {
00230                     ret = MEMORY_E;
00231                 }
00232 #else
00233                 ret = SIG_TYPE_E;
00234 #endif
00235                 break;
00236             }
00237 
00238             case WC_SIGNATURE_TYPE_NONE:
00239             default:
00240                 ret = BAD_FUNC_ARG;
00241                 break;
00242         }
00243     }
00244 
00245     if (hash_data) {
00246         XFREE(hash_data, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00247     }
00248 
00249     return ret;
00250 }
00251 
00252 int wc_SignatureGenerate(
00253     enum wc_HashType hash_type, enum wc_SignatureType sig_type,
00254     const byte* data, word32 data_len,
00255     byte* sig, word32 *sig_len,
00256     const void* key, word32 key_len, WC_RNG* rng)
00257 {
00258     int ret;
00259     word32 hash_len;
00260     byte *hash_data = NULL;
00261 
00262     /* Suppress possible unused arg if all signature types are disabled */
00263     (void)rng;
00264 
00265     /* Check arguments */
00266     if (data == NULL || data_len <= 0 || sig == NULL || sig_len == NULL ||
00267         *sig_len <= 0 || key == NULL || key_len <= 0) {
00268         return BAD_FUNC_ARG;
00269     }
00270 
00271     /* Validate signature len (needs to be at least max) */
00272     if ((int)*sig_len < wc_SignatureGetSize(sig_type, key, key_len)) {
00273         WOLFSSL_MSG("wc_SignatureGenerate: Invalid sig type/len");
00274         return BAD_FUNC_ARG;
00275     }
00276 
00277     /* Validate hash size */
00278     ret = wc_HashGetDigestSize(hash_type);
00279     if (ret < 0) {
00280         WOLFSSL_MSG("wc_SignatureGenerate: Invalid hash type/len");
00281         return ret;
00282     }
00283     hash_len = ret;
00284 
00285     /* Allocate temporary buffer for hash data */
00286     hash_data = (byte*)XMALLOC(hash_len, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00287     if (hash_data == NULL) {
00288         return MEMORY_E;
00289     }
00290 
00291     /* Perform hash of data */
00292     ret = wc_Hash(hash_type, data, data_len, hash_data, hash_len);
00293     if (ret == 0) {
00294         /* Create signature using hash as data */
00295         switch(sig_type) {
00296             case WC_SIGNATURE_TYPE_ECC:
00297 #if defined(HAVE_ECC) && defined(HAVE_ECC_SIGN)
00298                 /* Create signature using provided ECC key */
00299                 ret = wc_ecc_sign_hash(hash_data, hash_len, sig, sig_len, rng, (ecc_key*)key);
00300 #else
00301                 ret = SIG_TYPE_E;
00302 #endif
00303                 break;
00304 
00305             case WC_SIGNATURE_TYPE_RSA_W_ENC:
00306 #if defined(NO_RSA) || defined(NO_ASN)
00307                 ret = SIG_TYPE_E;
00308                 break;
00309 #else
00310                 ret = wc_SignatureDerEncode(hash_type, &hash_data, &hash_len);
00311                 /* Check for error */
00312                 if (ret < 0) {
00313                     break;
00314                 }
00315                 /* Otherwise fall-through and perform normal RSA sign against updated
00316                  * DER encoding + hash */
00317 #endif
00318 
00319             case WC_SIGNATURE_TYPE_RSA:
00320 #ifndef NO_RSA
00321                 /* Create signature using provided RSA key */
00322                 ret = wc_RsaSSL_Sign(hash_data, hash_len, sig, *sig_len, (RsaKey*)key, rng);
00323                 if (ret >= 0) {
00324                     *sig_len = ret;
00325                     ret = 0; /* Success */
00326                 }
00327 #else
00328                 ret = SIG_TYPE_E;
00329 #endif
00330                 break;
00331 
00332             case WC_SIGNATURE_TYPE_NONE:
00333             default:
00334                 ret = BAD_FUNC_ARG;
00335                 break;
00336         }
00337     }
00338 
00339     if (hash_data) {
00340         XFREE(hash_data, NULL, DYNAMIC_TYPE_TMP_BUFFER);
00341     }
00342 
00343     return ret;
00344 }
00345 
00346 #endif /* NO_SIG_WRAPPER */
00347