/* EME_OAEP as defined in RFC 2437 (PKCS #1 v2.0) */
-#ifndef NO_SHA
+#if !defined(NO_SHA) && !defined(NO_SHA1)
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/bn.h>
return (0);
}
- dbmask = Malloc(emlen - SHA_DIGEST_LENGTH);
+ dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH);
if (dbmask == NULL)
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
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);
- RAND_bytes(seed, SHA_DIGEST_LENGTH);
+ if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0)
+ return (0);
#ifdef PKCS_TESTVECT
memcpy(seed,
"\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f",
for (i = 0; i < SHA_DIGEST_LENGTH; i++)
seed[i] ^= seedmask[i];
- Free(dbmask);
+ OPENSSL_free(dbmask);
return (1);
}
{
int i, dblen, mlen = -1;
unsigned char *maskeddb;
- unsigned char *db, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
+ int lzero;
+ unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
- if (flen < 2 * SHA_DIGEST_LENGTH + 1)
- {
- RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR);
- return (-1);
- }
+ if (--num < 2 * SHA_DIGEST_LENGTH + 1)
+ goto decoding_err;
- dblen = flen - SHA_DIGEST_LENGTH;
- db = Malloc(dblen);
+ lzero = num - flen;
+ if (lzero < 0)
+ goto decoding_err;
+ maskeddb = from - lzero + SHA_DIGEST_LENGTH;
+
+ dblen = num - SHA_DIGEST_LENGTH;
+ db = OPENSSL_malloc(dblen);
if (db == NULL)
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
return (-1);
}
- maskeddb = from + SHA_DIGEST_LENGTH;
-
MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen);
- for (i = 0; i < SHA_DIGEST_LENGTH; i++)
- seed[i] ^= from[i];
+ for (i = lzero; i < SHA_DIGEST_LENGTH; i++)
+ seed[i] ^= from[i - lzero];
MGF1(db, dblen, seed, SHA_DIGEST_LENGTH);
for (i = 0; i < dblen; i++)
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++)
if (db[i] != 0x00)
break;
if (db[i] != 0x01 || i++ >= dblen)
- RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP,
- RSA_R_OAEP_DECODING_ERROR);
+ goto decoding_err;
else
{
mlen = dblen - i;
if (tlen < mlen)
{
- RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE);
+ RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE);
mlen = -1;
}
else
memcpy(to, db + i, mlen);
}
}
- Free(db);
+ 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, unsigned char *seed, long seedlen)