diff options
Diffstat (limited to 'crypto/rsa/rsa_oaep.c')
-rw-r--r-- | crypto/rsa/rsa_oaep.c | 105 |
1 files changed, 66 insertions, 39 deletions
diff --git a/crypto/rsa/rsa_oaep.c b/crypto/rsa/rsa_oaep.c index af4d24a56e..5446d4db92 100644 --- a/crypto/rsa/rsa_oaep.c +++ b/crypto/rsa/rsa_oaep.c @@ -28,41 +28,55 @@ #include <openssl/rand.h> #include <openssl/sha.h> -static int MGF1(unsigned char *mask, long len, - const unsigned char *seed, long seedlen); - int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, const unsigned char *from, int flen, const unsigned char *param, int plen) { + return RSA_padding_add_PKCS1_OAEP_mgf1(to, tlen, from, flen, + param, plen, NULL, NULL); + } + +int RSA_padding_add_PKCS1_OAEP_mgf1(unsigned char *to, int tlen, + const unsigned char *from, int flen, + const unsigned char *param, int plen, + const EVP_MD *md, const EVP_MD *mgf1md) + { int i, emlen = tlen - 1; unsigned char *db, *seed; - unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH]; + unsigned char *dbmask, seedmask[EVP_MAX_MD_SIZE]; + int mdlen; + + if (md == NULL) + md = EVP_sha1(); + if (mgf1md == NULL) + mgf1md = md; - if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1) + mdlen = EVP_MD_size(md); + + if (flen > emlen - 2 * mdlen - 1) { - RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP_MGF1, RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); return 0; } - if (emlen < 2 * SHA_DIGEST_LENGTH + 1) + if (emlen < 2 * mdlen + 1) { - RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL); + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP_MGF1, RSA_R_KEY_SIZE_TOO_SMALL); return 0; } to[0] = 0; seed = to + 1; - db = to + SHA_DIGEST_LENGTH + 1; + db = to + mdlen + 1; - if (!EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL)) + if (!EVP_Digest((void *)param, plen, db, NULL, md, NULL)) return 0; - memset(db + SHA_DIGEST_LENGTH, 0, - emlen - flen - 2 * SHA_DIGEST_LENGTH - 1); - db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01; - memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen); - if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0) + memset(db + mdlen, 0, + emlen - flen - 2 * mdlen - 1); + db[emlen - flen - mdlen - 1] = 0x01; + memcpy(db + emlen - flen - mdlen, from, (unsigned int) flen); + if (RAND_bytes(seed, mdlen) <= 0) return 0; #ifdef PKCS_TESTVECT memcpy(seed, @@ -70,21 +84,21 @@ int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, 20); #endif - dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH); + dbmask = OPENSSL_malloc(emlen - mdlen); if (dbmask == NULL) { - RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP_MGF1, ERR_R_MALLOC_FAILURE); return 0; } - if (MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH) < 0) + if (PKCS1_MGF1(dbmask, emlen - mdlen, seed, mdlen, mgf1md) < 0) return 0; - for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++) + for (i = 0; i < emlen - mdlen; i++) db[i] ^= dbmask[i]; - if (MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH) < 0) + if (PKCS1_MGF1(seedmask, mdlen, db, emlen - mdlen, mgf1md) < 0) return 0; - for (i = 0; i < SHA_DIGEST_LENGTH; i++) + for (i = 0; i < mdlen; i++) seed[i] ^= seedmask[i]; OPENSSL_free(dbmask); @@ -95,14 +109,32 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, const unsigned char *from, int flen, int num, const unsigned char *param, int plen) { + return RSA_padding_check_PKCS1_OAEP_mgf1(to, tlen, from , flen, num, + param, plen, + NULL, NULL); + } + +int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen, + const unsigned char *from, int flen, int num, + const unsigned char *param, int plen, + const EVP_MD *md, const EVP_MD *mgf1md) + { int i, dblen, mlen = -1; const unsigned char *maskeddb; int lzero; - unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; + unsigned char *db = NULL, seed[EVP_MAX_MD_SIZE], phash[EVP_MAX_MD_SIZE]; unsigned char *padded_from; int bad = 0; + int mdlen; - if (--num < 2 * SHA_DIGEST_LENGTH + 1) + if (md == NULL) + md = EVP_sha1(); + if (mgf1md == NULL) + mgf1md = md; + + mdlen = EVP_MD_size(md); + + if (--num < 2 * mdlen + 1) /* 'num' is the length of the modulus, i.e. does not depend on the * particular ciphertext. */ goto decoding_err; @@ -120,11 +152,11 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, flen = num; /* don't overflow the memcpy to padded_from */ } - dblen = num - SHA_DIGEST_LENGTH; + dblen = num - mdlen; db = OPENSSL_malloc(dblen + num); if (db == NULL) { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, ERR_R_MALLOC_FAILURE); return -1; } @@ -134,26 +166,26 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, memset(padded_from, 0, lzero); memcpy(padded_from + lzero, from, flen); - maskeddb = padded_from + SHA_DIGEST_LENGTH; + maskeddb = padded_from + mdlen; - if (MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen)) + if (PKCS1_MGF1(seed, mdlen, maskeddb, dblen, mgf1md)) return -1; - for (i = 0; i < SHA_DIGEST_LENGTH; i++) + for (i = 0; i < mdlen; i++) seed[i] ^= padded_from[i]; - if (MGF1(db, dblen, seed, SHA_DIGEST_LENGTH)) + if (PKCS1_MGF1(db, dblen, seed, mdlen, mgf1md)) return -1; for (i = 0; i < dblen; i++) db[i] ^= maskeddb[i]; - if (!EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL)) + if (!EVP_Digest((void *)param, plen, phash, NULL, md, NULL)) return -1; - if (CRYPTO_memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) + if (CRYPTO_memcmp(db, phash, mdlen) != 0 || bad) goto decoding_err; else { - for (i = SHA_DIGEST_LENGTH; i < dblen; i++) + for (i = mdlen; i < dblen; i++) if (db[i] != 0x00) break; if (i == dblen || db[i] != 0x01) @@ -165,7 +197,7 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, mlen = dblen - ++i; if (tlen < mlen) { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE); + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, RSA_R_DATA_TOO_LARGE); mlen = -1; } else @@ -178,7 +210,7 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, decoding_err: /* to avoid chosen ciphertext attacks, the error message should not reveal * which kind of decoding error happened */ - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, RSA_R_OAEP_DECODING_ERROR); if (db != NULL) OPENSSL_free(db); return -1; } @@ -227,9 +259,4 @@ int PKCS1_MGF1(unsigned char *mask, long len, return rv; } -static int MGF1(unsigned char *mask, long len, const unsigned char *seed, - long seedlen) - { - return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1()); - } #endif |