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| author | Bodo Möller <bodo@openssl.org> | 2001-06-06 20:48:49 +0200 |
|---|---|---|
| committer | Bodo Möller <bodo@openssl.org> | 2001-06-06 20:48:49 +0200 |
| commit | 20e021bf41828439529eb7839286bf919ba7dfc4 (patch) | |
| tree | 891b2c18303377f9226cc29e30ce5fd6a31a1d2b | |
| parent | move check to avoid memory leak. (diff) | |
| download | openssl-20e021bf41828439529eb7839286bf919ba7dfc4.tar.xz openssl-20e021bf41828439529eb7839286bf919ba7dfc4.zip | |
when checking OAEP, signal just a single kind of 'decoding error'
| -rw-r--r-- | crypto/rsa/rsa_oaep.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/crypto/rsa/rsa_oaep.c b/crypto/rsa/rsa_oaep.c index 64b59ee121..a893142fdb 100644 --- a/crypto/rsa/rsa_oaep.c +++ b/crypto/rsa/rsa_oaep.c @@ -94,20 +94,14 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, int i, dblen, mlen = -1; const unsigned char *maskeddb; int lzero; - unsigned char *db, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; + unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; if (--num < 2 * SHA_DIGEST_LENGTH + 1) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); - return (-1); - } + goto decoding_err; lzero = num - flen; if (lzero < 0) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); - return (-1); - } + goto decoding_err; maskeddb = from - lzero + SHA_DIGEST_LENGTH; dblen = num - SHA_DIGEST_LENGTH; @@ -129,7 +123,7 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, SHA1(param, plen, phash); if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0) - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); + goto decoding_err; else { for (i = SHA_DIGEST_LENGTH; i < dblen; i++) @@ -152,6 +146,13 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, } OPENSSL_free(db); return (mlen); + +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); + if (db != NULL) OPENSSL_free(db); + return -1; } int MGF1(unsigned char *mask, long len, |