2 * Copyright 2005-2016 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];
51 hLen = EVP_MD_size(Hash);
55 * Negative sLen has special meanings:
57 * -2 salt length is autorecovered from signature
65 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
69 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
70 emLen = RSA_size(rsa);
71 if (EM[0] & (0xFF << MSBits)) {
72 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID);
79 if (emLen < (hLen + sLen + 2)) { /* sLen can be small negative */
80 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
83 if (EM[emLen - 1] != 0xbc) {
84 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID);
87 maskedDBLen = emLen - hLen - 1;
89 DB = OPENSSL_malloc(maskedDBLen);
91 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE);
94 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
96 for (i = 0; i < maskedDBLen; i++)
99 DB[0] &= 0xFF >> (8 - MSBits);
100 for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) ;
101 if (DB[i++] != 0x1) {
102 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED);
105 if (sLen >= 0 && (maskedDBLen - i) != sLen) {
106 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
109 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
110 || !EVP_DigestUpdate(ctx, zeroes, sizeof zeroes)
111 || !EVP_DigestUpdate(ctx, mHash, hLen))
113 if (maskedDBLen - i) {
114 if (!EVP_DigestUpdate(ctx, DB + i, maskedDBLen - i))
117 if (!EVP_DigestFinal_ex(ctx, H_, NULL))
119 if (memcmp(H_, H, hLen)) {
120 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE);
127 EVP_MD_CTX_free(ctx);
133 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
134 const unsigned char *mHash,
135 const EVP_MD *Hash, int sLen)
137 return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
140 int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
141 const unsigned char *mHash,
142 const EVP_MD *Hash, const EVP_MD *mgf1Hash,
147 int hLen, maskedDBLen, MSBits, emLen;
148 unsigned char *H, *salt = NULL, *p;
149 EVP_MD_CTX *ctx = NULL;
151 if (mgf1Hash == NULL)
154 hLen = EVP_MD_size(Hash);
158 * Negative sLen has special meanings:
160 * -2 salt length is maximized
167 else if (sLen < -2) {
168 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
172 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
173 emLen = RSA_size(rsa);
179 sLen = emLen - hLen - 2;
180 } else if (emLen < (hLen + sLen + 2)) {
181 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
182 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
186 salt = OPENSSL_malloc(sLen);
188 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
189 ERR_R_MALLOC_FAILURE);
192 if (RAND_bytes(salt, sLen) <= 0)
195 maskedDBLen = emLen - hLen - 1;
196 H = EM + maskedDBLen;
197 ctx = EVP_MD_CTX_new();
200 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
201 || !EVP_DigestUpdate(ctx, zeroes, sizeof zeroes)
202 || !EVP_DigestUpdate(ctx, mHash, hLen))
204 if (sLen && !EVP_DigestUpdate(ctx, salt, sLen))
206 if (!EVP_DigestFinal_ex(ctx, H, NULL))
209 /* Generate dbMask in place then perform XOR on it */
210 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash))
216 * Initial PS XORs with all zeroes which is a NOP so just update pointer.
217 * Note from a test above this value is guaranteed to be non-negative.
219 p += emLen - sLen - hLen - 2;
222 for (i = 0; i < sLen; i++)
226 EM[0] &= 0xFF >> (8 - MSBits);
228 /* H is already in place so just set final 0xbc */
230 EM[emLen - 1] = 0xbc;
235 EVP_MD_CTX_free(ctx);
242 #if defined(_MSC_VER)
243 # pragma optimize("",on)