2 * Copyright 2005-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include "internal/cryptlib.h"
12 #include <openssl/bn.h>
13 #include <openssl/rsa.h>
14 #include <openssl/evp.h>
15 #include <openssl/rand.h>
16 #include <openssl/sha.h>
19 static const unsigned char zeroes[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
21 #if defined(_MSC_VER) && defined(_ARM_)
22 # pragma optimize("g", off)
25 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
26 const EVP_MD *Hash, const unsigned char *EM,
29 return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen);
32 int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash,
33 const EVP_MD *Hash, const EVP_MD *mgf1Hash,
34 const unsigned char *EM, int sLen)
38 int hLen, maskedDBLen, MSBits, emLen;
39 const unsigned char *H;
40 unsigned char *DB = NULL;
41 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
42 unsigned char H_[EVP_MAX_MD_SIZE];
50 hLen = EVP_MD_size(Hash);
54 * Negative sLen has special meanings:
56 * -2 salt length is autorecovered from signature
57 * -3 salt length is maximized
60 if (sLen == RSA_PSS_SALTLEN_DIGEST) {
62 } else if (sLen < RSA_PSS_SALTLEN_MAX) {
63 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
67 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
68 emLen = RSA_size(rsa);
69 if (EM[0] & (0xFF << MSBits)) {
70 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID);
77 if (emLen < hLen + 2) {
78 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
81 if (sLen == RSA_PSS_SALTLEN_MAX) {
82 sLen = emLen - hLen - 2;
83 } else if (sLen > emLen - hLen - 2) { /* sLen can be small negative */
84 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
87 if (EM[emLen - 1] != 0xbc) {
88 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID);
91 maskedDBLen = emLen - hLen - 1;
93 DB = OPENSSL_malloc(maskedDBLen);
95 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE);
98 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
100 for (i = 0; i < maskedDBLen; i++)
103 DB[0] &= 0xFF >> (8 - MSBits);
104 for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) ;
105 if (DB[i++] != 0x1) {
106 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED);
109 if (sLen != RSA_PSS_SALTLEN_AUTO && (maskedDBLen - i) != sLen) {
110 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
113 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
114 || !EVP_DigestUpdate(ctx, zeroes, sizeof(zeroes))
115 || !EVP_DigestUpdate(ctx, mHash, hLen))
117 if (maskedDBLen - i) {
118 if (!EVP_DigestUpdate(ctx, DB + i, maskedDBLen - i))
121 if (!EVP_DigestFinal_ex(ctx, H_, NULL))
123 if (memcmp(H_, H, hLen)) {
124 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE);
132 EVP_MD_CTX_free(ctx);
138 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
139 const unsigned char *mHash,
140 const EVP_MD *Hash, int sLen)
142 return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
145 int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
146 const unsigned char *mHash,
147 const EVP_MD *Hash, const EVP_MD *mgf1Hash,
152 int hLen, maskedDBLen, MSBits, emLen;
153 unsigned char *H, *salt = NULL, *p;
154 EVP_MD_CTX *ctx = NULL;
156 if (mgf1Hash == NULL)
159 hLen = EVP_MD_size(Hash);
163 * Negative sLen has special meanings:
165 * -2 salt length is maximized
166 * -3 same as above (on signing)
169 if (sLen == RSA_PSS_SALTLEN_DIGEST) {
171 } else if (sLen == RSA_PSS_SALTLEN_MAX_SIGN) {
172 sLen = RSA_PSS_SALTLEN_MAX;
173 } else if (sLen < RSA_PSS_SALTLEN_MAX) {
174 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
178 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
179 emLen = RSA_size(rsa);
184 if (emLen < hLen + 2) {
185 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
186 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
189 if (sLen == RSA_PSS_SALTLEN_MAX) {
190 sLen = emLen - hLen - 2;
191 } else if (sLen > emLen - hLen - 2) {
192 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
193 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
197 salt = OPENSSL_malloc(sLen);
199 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
200 ERR_R_MALLOC_FAILURE);
203 if (RAND_bytes(salt, sLen) <= 0)
206 maskedDBLen = emLen - hLen - 1;
207 H = EM + maskedDBLen;
208 ctx = EVP_MD_CTX_new();
211 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
212 || !EVP_DigestUpdate(ctx, zeroes, sizeof(zeroes))
213 || !EVP_DigestUpdate(ctx, mHash, hLen))
215 if (sLen && !EVP_DigestUpdate(ctx, salt, sLen))
217 if (!EVP_DigestFinal_ex(ctx, H, NULL))
220 /* Generate dbMask in place then perform XOR on it */
221 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash))
227 * Initial PS XORs with all zeroes which is a NOP so just update pointer.
228 * Note from a test above this value is guaranteed to be non-negative.
230 p += emLen - sLen - hLen - 2;
233 for (i = 0; i < sLen; i++)
237 EM[0] &= 0xFF >> (8 - MSBits);
239 /* H is already in place so just set final 0xbc */
241 EM[emLen - 1] = 0xbc;
246 EVP_MD_CTX_free(ctx);
247 OPENSSL_clear_free(salt, (size_t)sLen); /* salt != NULL implies sLen > 0 */
253 #if defined(_MSC_VER)
254 # pragma optimize("",on)