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Fixes for unusual key lengths an PSS.

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This commit is contained in:
Dr. Stephen Henson 2005-06-01 22:06:46 +00:00
parent 0dfe532ea9
commit 5858d32a59
1 changed files with 21 additions and 9 deletions
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30
crypto/rsa/rsa_pss.c
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@ -71,13 +71,13 @@ int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
{
int i;
int ret = 0;
int hLen, maskedDBLen, emBits, emLen;
int hLen, maskedDBLen, MSBits, emLen;
const unsigned char *H;
unsigned char *DB = NULL;
EVP_MD_CTX ctx;
unsigned char H_[EVP_MAX_MD_SIZE];
emBits = BN_num_bits(rsa->n) - 1;
emLen = (emBits + 7) >> 3;
MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
emLen = RSA_size(rsa);
hLen = EVP_MD_size(Hash);
if (emLen < (hLen + sLen + 2))
{
@ -89,11 +89,16 @@ int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_LAST_OCTET_INVALID);
goto err;
}
if (EM[0] & (0xFF << (emBits & 0x7)))
if (EM[0] & (0xFF << MSBits))
{
RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_FIRST_OCTET_INVALID);
goto err;
}
if (!MSBits)
{
EM++;
emLen--;
}
maskedDBLen = emLen - hLen - 1;
H = EM + maskedDBLen;
DB = OPENSSL_malloc(maskedDBLen);
@ -105,7 +110,8 @@ int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
PKCS1_MGF1(DB, maskedDBLen, H, hLen, Hash);
for (i = 0; i < maskedDBLen; i++)
DB[i] ^= EM[i];
DB[0] &= 0xFF >> (8 - (emBits & 0x7));
if (MSBits)
DB[0] &= 0xFF >> (8 - MSBits);
for (i = 0; i < (emLen - hLen - sLen - 2); i++)
{
if (DB[i] != 0)
@ -150,11 +156,11 @@ int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
{
int i;
int ret = 0;
int hLen, maskedDBLen, emBits, emLen;
int hLen, maskedDBLen, MSBits, emLen;
unsigned char *H, *salt = NULL, *p;
EVP_MD_CTX ctx;
emBits = BN_num_bits(rsa->n) - 1;
emLen = (emBits + 7) >> 3;
MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
emLen = RSA_size(rsa);
hLen = EVP_MD_size(Hash);
if (sLen < 0)
sLen = 0;
@ -164,6 +170,11 @@ int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
goto err;
}
if (MSBits == 0)
{
*EM++ = 0;
emLen--;
}
if (sLen > 0)
{
salt = OPENSSL_malloc(sLen);
@ -203,7 +214,8 @@ int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
for (i = 0; i < sLen; i++)
*p++ ^= salt[i];
}
EM[0] &= 0xFF >> (8 - (emBits & 0x7));
if (MSBits)
EM[0] &= 0xFF >> (8 - MSBits);
/* H is already in place so just set final 0xbc */