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];
50 hLen = EVP_MD_size(Hash);
54 * Negative sLen has special meanings:
56 * -2 salt length is autorecovered from signature
59 if (sLen == RSA_PSS_SALTLEN_DIGEST)
61 else if (sLen < RSA_PSS_SALTLEN_MAX) {
62 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
66 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
67 emLen = RSA_size(rsa);
68 if (EM[0] & (0xFF << MSBits)) {
69 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID);
76 if (sLen == RSA_PSS_SALTLEN_MAX) {
77 sLen = emLen - hLen - 2;
78 } else if (emLen < (hLen + sLen + 2)) { /* sLen can be small negative */
79 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
82 if (EM[emLen - 1] != 0xbc) {
83 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID);
86 maskedDBLen = emLen - hLen - 1;
88 DB = OPENSSL_malloc(maskedDBLen);
90 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE);
93 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
95 for (i = 0; i < maskedDBLen; i++)
98 DB[0] &= 0xFF >> (8 - MSBits);
99 for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) ;
100 if (DB[i++] != 0x1) {
101 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED);
104 if (sLen != RSA_PSS_SALTLEN_AUTO && (maskedDBLen - i) != sLen) {
105 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
108 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
109 || !EVP_DigestUpdate(ctx, zeroes, sizeof zeroes)
110 || !EVP_DigestUpdate(ctx, mHash, hLen))
112 if (maskedDBLen - i) {
113 if (!EVP_DigestUpdate(ctx, DB + i, maskedDBLen - i))
116 if (!EVP_DigestFinal_ex(ctx, H_, NULL))
118 if (memcmp(H_, H, hLen)) {
119 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE);
126 EVP_MD_CTX_free(ctx);
132 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
133 const unsigned char *mHash,
134 const EVP_MD *Hash, int sLen)
136 return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
139 int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
140 const unsigned char *mHash,
141 const EVP_MD *Hash, const EVP_MD *mgf1Hash,
146 int hLen, maskedDBLen, MSBits, emLen;
147 unsigned char *H, *salt = NULL, *p;
148 EVP_MD_CTX *ctx = NULL;
150 if (mgf1Hash == NULL)
153 hLen = EVP_MD_size(Hash);
157 * Negative sLen has special meanings:
159 * -2 salt length is maximized
162 if (sLen == RSA_PSS_SALTLEN_DIGEST)
164 else if (sLen == RSA_PSS_SALTLEN_MAX_SIGN)
165 sLen = RSA_PSS_SALTLEN_MAX;
166 else if (sLen < RSA_PSS_SALTLEN_MAX) {
167 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
171 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
172 emLen = RSA_size(rsa);
177 if (sLen == RSA_PSS_SALTLEN_MAX) {
178 sLen = emLen - hLen - 2;
179 } else if (emLen < (hLen + sLen + 2)) {
180 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
181 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
185 salt = OPENSSL_malloc(sLen);
187 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
188 ERR_R_MALLOC_FAILURE);
191 if (RAND_bytes(salt, sLen) <= 0)
194 maskedDBLen = emLen - hLen - 1;
195 H = EM + maskedDBLen;
196 ctx = EVP_MD_CTX_new();
199 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
200 || !EVP_DigestUpdate(ctx, zeroes, sizeof zeroes)
201 || !EVP_DigestUpdate(ctx, mHash, hLen))
203 if (sLen && !EVP_DigestUpdate(ctx, salt, sLen))
205 if (!EVP_DigestFinal_ex(ctx, H, NULL))
208 /* Generate dbMask in place then perform XOR on it */
209 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash))
215 * Initial PS XORs with all zeroes which is a NOP so just update pointer.
216 * Note from a test above this value is guaranteed to be non-negative.
218 p += emLen - sLen - hLen - 2;
221 for (i = 0; i < sLen; i++)
225 EM[0] &= 0xFF >> (8 - MSBits);
227 /* H is already in place so just set final 0xbc */
229 EM[emLen - 1] = 0xbc;
234 EVP_MD_CTX_free(ctx);
241 #if defined(_MSC_VER)
242 # pragma optimize("",on)