2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
5 /* ====================================================================
6 * Copyright (c) 2005 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/evp.h>
64 #include <openssl/rand.h>
65 #include <openssl/sha.h>
67 const static unsigned char zeroes[] = {0,0,0,0,0,0,0,0};
69 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
70 const EVP_MD *Hash, const unsigned char *EM, int sLen)
74 int hLen, maskedDBLen, MSBits, emLen;
75 const unsigned char *H;
76 unsigned char *DB = NULL;
78 unsigned char H_[EVP_MAX_MD_SIZE];
79 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
80 emLen = RSA_size(rsa);
81 hLen = EVP_MD_size(Hash);
82 if (emLen < (hLen + sLen + 2))
84 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_DATA_TOO_LARGE);
87 if (EM[emLen - 1] != 0xbc)
89 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_LAST_OCTET_INVALID);
92 if (EM[0] & (0xFF << MSBits))
94 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_FIRST_OCTET_INVALID);
102 maskedDBLen = emLen - hLen - 1;
103 H = EM + maskedDBLen;
104 DB = OPENSSL_malloc(maskedDBLen);
107 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, ERR_R_MALLOC_FAILURE);
110 PKCS1_MGF1(DB, maskedDBLen, H, hLen, Hash);
111 for (i = 0; i < maskedDBLen; i++)
114 DB[0] &= 0xFF >> (8 - MSBits);
115 for (i = 0; i < (emLen - hLen - sLen - 2); i++)
119 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS,
120 RSA_R_ZERO_CHECK_FAILED);
126 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_ONE_CHECK_FAILED);
129 EVP_MD_CTX_init(&ctx);
130 EVP_DigestInit_ex(&ctx, Hash, NULL);
131 EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes);
132 EVP_DigestUpdate(&ctx, mHash, hLen);
134 EVP_DigestUpdate(&ctx, DB + maskedDBLen - sLen, sLen);
135 EVP_DigestFinal(&ctx, H_, NULL);
136 EVP_MD_CTX_cleanup(&ctx);
137 if (memcmp(H_, H, hLen))
139 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_BAD_SIGNATURE);
153 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
154 const unsigned char *mHash,
155 const EVP_MD *Hash, int sLen)
159 int hLen, maskedDBLen, MSBits, emLen;
160 unsigned char *H, *salt = NULL, *p;
162 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
163 emLen = RSA_size(rsa);
164 hLen = EVP_MD_size(Hash);
167 if (emLen < (hLen + sLen + 2))
169 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS,
170 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
180 salt = OPENSSL_malloc(sLen);
183 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS,
184 ERR_R_MALLOC_FAILURE);
187 if (!RAND_bytes(salt, sLen))
190 maskedDBLen = emLen - hLen - 1;
191 H = EM + maskedDBLen;
192 EVP_MD_CTX_init(&ctx);
193 EVP_DigestInit_ex(&ctx, Hash, NULL);
194 EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes);
195 EVP_DigestUpdate(&ctx, mHash, hLen);
197 EVP_DigestUpdate(&ctx, salt, sLen);
198 EVP_DigestFinal(&ctx, H, NULL);
199 EVP_MD_CTX_cleanup(&ctx);
201 /* Generate dbMask in place then perform XOR on it */
202 PKCS1_MGF1(EM, maskedDBLen, H, hLen, Hash);
206 /* Initial PS XORs with all zeroes which is a NOP so just update
207 * pointer. Note from a test above this value is guaranteed to
210 p += emLen - sLen - hLen - 2;
214 for (i = 0; i < sLen; i++)
218 EM[0] &= 0xFF >> (8 - MSBits);
220 /* H is already in place so just set final 0xbc */
222 EM[emLen - 1] = 0xbc;