2 * Copyright 2005-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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 * RSA low level APIs are deprecated for public use, but still ok for
14 #include "internal/deprecated.h"
17 #include "internal/cryptlib.h"
18 #include <openssl/bn.h>
19 #include <openssl/rsa.h>
20 #include <openssl/evp.h>
21 #include <openssl/rand.h>
22 #include <openssl/sha.h>
23 #include "rsa_local.h"
25 static const unsigned char zeroes[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
27 #if defined(_MSC_VER) && defined(_ARM_)
28 # pragma optimize("g", off)
31 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
32 const EVP_MD *Hash, const unsigned char *EM,
35 return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen);
38 int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash,
39 const EVP_MD *Hash, const EVP_MD *mgf1Hash,
40 const unsigned char *EM, int sLen)
44 int hLen, maskedDBLen, MSBits, emLen;
45 const unsigned char *H;
46 unsigned char *DB = NULL;
47 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
48 unsigned char H_[EVP_MAX_MD_SIZE];
56 hLen = EVP_MD_size(Hash);
60 * Negative sLen has special meanings:
62 * -2 salt length is autorecovered from signature
63 * -3 salt length is maximized
66 if (sLen == RSA_PSS_SALTLEN_DIGEST) {
68 } else if (sLen < RSA_PSS_SALTLEN_MAX) {
69 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
73 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
74 emLen = RSA_size(rsa);
75 if (EM[0] & (0xFF << MSBits)) {
76 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID);
83 if (emLen < hLen + 2) {
84 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
87 if (sLen == RSA_PSS_SALTLEN_MAX) {
88 sLen = emLen - hLen - 2;
89 } else if (sLen > emLen - hLen - 2) { /* sLen can be small negative */
90 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE);
93 if (EM[emLen - 1] != 0xbc) {
94 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID);
97 maskedDBLen = emLen - hLen - 1;
99 DB = OPENSSL_malloc(maskedDBLen);
101 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE);
104 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
106 for (i = 0; i < maskedDBLen; i++)
109 DB[0] &= 0xFF >> (8 - MSBits);
110 for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++) ;
111 if (DB[i++] != 0x1) {
112 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED);
115 if (sLen != RSA_PSS_SALTLEN_AUTO && (maskedDBLen - i) != sLen) {
116 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
119 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
120 || !EVP_DigestUpdate(ctx, zeroes, sizeof(zeroes))
121 || !EVP_DigestUpdate(ctx, mHash, hLen))
123 if (maskedDBLen - i) {
124 if (!EVP_DigestUpdate(ctx, DB + i, maskedDBLen - i))
127 if (!EVP_DigestFinal_ex(ctx, H_, NULL))
129 if (memcmp(H_, H, hLen)) {
130 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE);
138 EVP_MD_CTX_free(ctx);
144 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
145 const unsigned char *mHash,
146 const EVP_MD *Hash, int sLen)
148 return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
151 int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
152 const unsigned char *mHash,
153 const EVP_MD *Hash, const EVP_MD *mgf1Hash,
158 int hLen, maskedDBLen, MSBits, emLen;
159 unsigned char *H, *salt = NULL, *p;
160 EVP_MD_CTX *ctx = NULL;
162 if (mgf1Hash == NULL)
165 hLen = EVP_MD_size(Hash);
169 * Negative sLen has special meanings:
171 * -2 salt length is maximized
172 * -3 same as above (on signing)
175 if (sLen == RSA_PSS_SALTLEN_DIGEST) {
177 } else if (sLen == RSA_PSS_SALTLEN_MAX_SIGN) {
178 sLen = RSA_PSS_SALTLEN_MAX;
179 } else if (sLen < RSA_PSS_SALTLEN_MAX) {
180 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED);
184 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
185 emLen = RSA_size(rsa);
190 if (emLen < hLen + 2) {
191 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
192 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
195 if (sLen == RSA_PSS_SALTLEN_MAX) {
196 sLen = emLen - hLen - 2;
197 } else if (sLen > emLen - hLen - 2) {
198 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
199 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
203 salt = OPENSSL_malloc(sLen);
205 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,
206 ERR_R_MALLOC_FAILURE);
209 if (RAND_bytes(salt, sLen) <= 0)
212 maskedDBLen = emLen - hLen - 1;
213 H = EM + maskedDBLen;
214 ctx = EVP_MD_CTX_new();
217 if (!EVP_DigestInit_ex(ctx, Hash, NULL)
218 || !EVP_DigestUpdate(ctx, zeroes, sizeof(zeroes))
219 || !EVP_DigestUpdate(ctx, mHash, hLen))
221 if (sLen && !EVP_DigestUpdate(ctx, salt, sLen))
223 if (!EVP_DigestFinal_ex(ctx, H, NULL))
226 /* Generate dbMask in place then perform XOR on it */
227 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash))
233 * Initial PS XORs with all zeroes which is a NOP so just update pointer.
234 * Note from a test above this value is guaranteed to be non-negative.
236 p += emLen - sLen - hLen - 2;
239 for (i = 0; i < sLen; i++)
243 EM[0] &= 0xFF >> (8 - MSBits);
245 /* H is already in place so just set final 0xbc */
247 EM[emLen - 1] = 0xbc;
252 EVP_MD_CTX_free(ctx);
253 OPENSSL_clear_free(salt, (size_t)sLen); /* salt != NULL implies sLen > 0 */
259 #if defined(_MSC_VER)
260 # pragma optimize("",on)