From 3d5afc8b83632c712d9ee62f6c5421a7fe5ace58 Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Thu, 2 Jun 2005 18:29:21 +0000
Subject: [PATCH] PSS update [from 0.9.7].
---
crypto/rsa/rsa.h | 4 +-
crypto/rsa/rsa_err.c | 4 +-
crypto/rsa/rsa_pss.c | 89 +++++++++++++++++++++++++++++---------------
3 files changed, 63 insertions(+), 34 deletions(-)
diff --git a/crypto/rsa/rsa.h b/crypto/rsa/rsa.h
index 1f6131b42..a1ca34760 100644
--- a/crypto/rsa/rsa.h
+++ b/crypto/rsa/rsa.h
@@ -411,7 +411,7 @@ 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
@@ -421,7 +421,7 @@ 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 48e8f3931..cfb1e908a 100644
--- a/crypto/rsa/rsa_err.c
+++ b/crypto/rsa/rsa_err.c
@@ -141,7 +141,7 @@ 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"},
@@ -151,7 +151,7 @@ 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 5dcdb5460..2815628f5 100644
--- a/crypto/rsa/rsa_pss.c
+++ b/crypto/rsa/rsa_pss.c
@@ -76,10 +76,35 @@ 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];
+
+ hLen = EVP_MD_size(Hash);
+ /*
+ * 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_SLEN_CHECK_FAILED);
+ goto err;
+ }
+
MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
emLen = RSA_size(rsa);
- hLen = EVP_MD_size(Hash);
- if (emLen < (hLen + sLen + 2))
+ if (EM[0] & (0xFF << MSBits))
+ {
+ RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_FIRST_OCTET_INVALID);
+ goto err;
+ }
+ 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;
@@ -89,16 +114,6 @@ 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 << 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);
@@ -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);