From: Andy Polyakov Date: Thu, 2 Jun 2005 18:07:16 +0000 (+0000) Subject: Make PSS more flexible, most notably assign special meaning to negative X-Git-Tag: FIPS_TEST_9~18 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=bb792a485aedb7f095139b3a7a30d6f5def7f8a7;p=oweals%2Fopenssl.git Make PSS more flexible, most notably assign special meaning to negative sLen values: -1 -> sLen = hLen, -2 -> sLen autochosen/autorecovered. --- diff --git a/crypto/rsa/rsa.h b/crypto/rsa/rsa.h index f9495863cc..b02b48be0a 100644 --- a/crypto/rsa/rsa.h +++ b/crypto/rsa/rsa.h @@ -389,7 +389,7 @@ void ERR_load_RSA_strings(void); #define RSA_R_NULL_BEFORE_BLOCK_MISSING 113 #define RSA_R_N_DOES_NOT_EQUAL_P_Q 127 #define RSA_R_OAEP_DECODING_ERROR 121 -#define RSA_R_ONE_CHECK_FAILED 135 +#define RSA_R_SLEN_RECOVERY_FAILED 135 #define RSA_R_PADDING_CHECK_FAILED 114 #define RSA_R_P_NOT_PRIME 128 #define RSA_R_Q_NOT_PRIME 129 @@ -399,7 +399,7 @@ void ERR_load_RSA_strings(void); #define RSA_R_UNKNOWN_ALGORITHM_TYPE 117 #define RSA_R_UNKNOWN_PADDING_TYPE 118 #define RSA_R_WRONG_SIGNATURE_LENGTH 119 -#define RSA_R_ZERO_CHECK_FAILED 136 +#define RSA_R_SLEN_CHECK_FAILED 136 #ifdef __cplusplus } diff --git a/crypto/rsa/rsa_err.c b/crypto/rsa/rsa_err.c index 5e8349dfcf..2ec4b30ff7 100644 --- a/crypto/rsa/rsa_err.c +++ b/crypto/rsa/rsa_err.c @@ -132,7 +132,7 @@ static ERR_STRING_DATA RSA_str_reasons[]= {ERR_REASON(RSA_R_NULL_BEFORE_BLOCK_MISSING),"null before block missing"}, {ERR_REASON(RSA_R_N_DOES_NOT_EQUAL_P_Q) ,"n does not equal p q"}, {ERR_REASON(RSA_R_OAEP_DECODING_ERROR) ,"oaep decoding error"}, -{ERR_REASON(RSA_R_ONE_CHECK_FAILED) ,"one check failed"}, +{ERR_REASON(RSA_R_SLEN_RECOVERY_FAILED) ,"salt length recovery failed"}, {ERR_REASON(RSA_R_PADDING_CHECK_FAILED) ,"padding check failed"}, {ERR_REASON(RSA_R_P_NOT_PRIME) ,"p not prime"}, {ERR_REASON(RSA_R_Q_NOT_PRIME) ,"q not prime"}, @@ -142,7 +142,7 @@ static ERR_STRING_DATA RSA_str_reasons[]= {ERR_REASON(RSA_R_UNKNOWN_ALGORITHM_TYPE),"unknown algorithm type"}, {ERR_REASON(RSA_R_UNKNOWN_PADDING_TYPE) ,"unknown padding type"}, {ERR_REASON(RSA_R_WRONG_SIGNATURE_LENGTH),"wrong signature length"}, -{ERR_REASON(RSA_R_ZERO_CHECK_FAILED) ,"zero check failed"}, +{ERR_REASON(RSA_R_SLEN_CHECK_FAILED) ,"salt length check failed"}, {0,NULL} }; diff --git a/crypto/rsa/rsa_pss.c b/crypto/rsa/rsa_pss.c index 5dcdb54603..2815628f5f 100644 --- a/crypto/rsa/rsa_pss.c +++ b/crypto/rsa/rsa_pss.c @@ -76,29 +76,44 @@ int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash, unsigned char *DB = NULL; EVP_MD_CTX ctx; unsigned char H_[EVP_MAX_MD_SIZE]; - MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; - emLen = RSA_size(rsa); + hLen = EVP_MD_size(Hash); - if (emLen < (hLen + sLen + 2)) - { - RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_DATA_TOO_LARGE); - goto err; - } - if (EM[emLen - 1] != 0xbc) + /* + * Negative sLen has special meanings: + * -1 sLen == hLen + * -2 salt length is autorecovered from signature + * -N reserved + */ + if (sLen == -1) sLen = hLen; + else if (sLen == -2) sLen = -2; + else if (sLen < -2) { - RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_LAST_OCTET_INVALID); + RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_SLEN_CHECK_FAILED); goto err; } + + MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; + emLen = RSA_size(rsa); if (EM[0] & (0xFF << MSBits)) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_FIRST_OCTET_INVALID); goto err; } - if (!MSBits) + if (MSBits == 0) { EM++; emLen--; } + if (emLen < (hLen + sLen + 2)) /* sLen can be small negative */ + { + RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_DATA_TOO_LARGE); + goto err; + } + if (EM[emLen - 1] != 0xbc) + { + RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_LAST_OCTET_INVALID); + goto err; + } maskedDBLen = emLen - hLen - 1; H = EM + maskedDBLen; DB = OPENSSL_malloc(maskedDBLen); @@ -112,26 +127,23 @@ int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash, DB[i] ^= EM[i]; if (MSBits) DB[0] &= 0xFF >> (8 - MSBits); - for (i = 0; i < (emLen - hLen - sLen - 2); i++) + for (i = 0; DB[i] == 0 && i < (maskedDBLen-1); i++) ; + if (DB[i++] != 0x1) { - if (DB[i] != 0) - { - RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, - RSA_R_ZERO_CHECK_FAILED); - goto err; - } + RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_SLEN_RECOVERY_FAILED); + goto err; } - if (DB[i] != 0x1) + if (sLen >= 0 && (maskedDBLen - i) != sLen) { - RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_ONE_CHECK_FAILED); + RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_SLEN_CHECK_FAILED); goto err; } EVP_MD_CTX_init(&ctx); EVP_DigestInit_ex(&ctx, Hash, NULL); EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes); EVP_DigestUpdate(&ctx, mHash, hLen); - if (sLen) - EVP_DigestUpdate(&ctx, DB + maskedDBLen - sLen, sLen); + if (maskedDBLen - i) + EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i); EVP_DigestFinal(&ctx, H_, NULL); EVP_MD_CTX_cleanup(&ctx); if (memcmp(H_, H, hLen)) @@ -159,22 +171,39 @@ int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM, int hLen, maskedDBLen, MSBits, emLen; unsigned char *H, *salt = NULL, *p; EVP_MD_CTX ctx; - MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; - emLen = RSA_size(rsa); + hLen = EVP_MD_size(Hash); - if (sLen < 0) - sLen = 0; - if (emLen < (hLen + sLen + 2)) + /* + * Negative sLen has special meanings: + * -1 sLen == hLen + * -2 salt length is maximized + * -N reserved + */ + if (sLen == -1) sLen = hLen; + else if (sLen == -2) sLen = -2; + else if (sLen < -2) { - RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS, - RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS, RSA_R_SLEN_CHECK_FAILED); goto err; } + + MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; + emLen = RSA_size(rsa); if (MSBits == 0) { *EM++ = 0; emLen--; } + if (sLen == -2) + { + sLen = emLen - hLen - 2; + } + else if (emLen < (hLen + sLen + 2)) + { + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS, + RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); + goto err; + } if (sLen > 0) { salt = OPENSSL_malloc(sLen);