{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP,
RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP,
RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
}
if (emlen < 2 * SHA_DIGEST_LENGTH + 1)
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL);
}
if (emlen < 2 * SHA_DIGEST_LENGTH + 1)
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL);
dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH);
if (dbmask == NULL)
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH);
if (dbmask == NULL)
{
RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
- EVP_Digest((void *)param, plen, db, NULL, EVP_sha1());
+ EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL);
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 + 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)
MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH);
for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++)
db[i] ^= dbmask[i];
MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH);
for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++)
db[i] ^= dbmask[i];
MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH);
for (i = 0; i < SHA_DIGEST_LENGTH; i++)
seed[i] ^= seedmask[i];
MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH);
for (i = 0; i < SHA_DIGEST_LENGTH; i++)
seed[i] ^= seedmask[i];
const unsigned char *maskeddb;
int lzero;
unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
const unsigned char *maskeddb;
int lzero;
unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
+ {
+ /* lzero == -1 */
+
+ /* signalling this error immediately after detection might allow
+ * for side-channel attacks (e.g. timing if 'plen' is huge
+ * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal
+ * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001),
+ * so we use a 'bad' flag */
+ bad = 1;
+ lzero = 0;
+ }
}
MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen);
}
MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen);
- EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1());
-
- if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0)
+ EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL);
+
+ if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad)
decoding_err:
/* to avoid chosen ciphertext attacks, the error message should not reveal
* which kind of decoding error happened */
decoding_err:
/* to avoid chosen ciphertext attacks, the error message should not reveal
* which kind of decoding error happened */
-int MGF1(unsigned char *mask, long len,
- const unsigned char *seed, long seedlen)
+int PKCS1_MGF1(unsigned char *mask, long len,
+ const unsigned char *seed, long seedlen, const EVP_MD *dgst)
for (i = 0; outlen < len; i++)
{
cnt[0] = (unsigned char)((i >> 24) & 255);
cnt[1] = (unsigned char)((i >> 16) & 255);
cnt[2] = (unsigned char)((i >> 8)) & 255;
cnt[3] = (unsigned char)(i & 255);
for (i = 0; outlen < len; i++)
{
cnt[0] = (unsigned char)((i >> 24) & 255);
cnt[1] = (unsigned char)((i >> 16) & 255);
cnt[2] = (unsigned char)((i >> 8)) & 255;
cnt[3] = (unsigned char)(i & 255);
EVP_DigestUpdate(&c, seed, seedlen);
EVP_DigestUpdate(&c, cnt, 4);
EVP_DigestUpdate(&c, seed, seedlen);
EVP_DigestUpdate(&c, cnt, 4);
- EVP_DigestFinal(&c, mask + outlen, NULL);
- outlen += SHA_DIGEST_LENGTH;
+ EVP_DigestFinal_ex(&c, mask + outlen, NULL);
+ outlen += mdlen;
+
+int MGF1(unsigned char *mask, long len, const unsigned char *seed, long seedlen)
+ {
+ return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1());
+ }