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-rw-r--r--src/lib/libcrypto/rsa/rsa_oaep.c212
1 files changed, 0 insertions, 212 deletions
diff --git a/src/lib/libcrypto/rsa/rsa_oaep.c b/src/lib/libcrypto/rsa/rsa_oaep.c
deleted file mode 100644
index d43ecaca63..0000000000
--- a/src/lib/libcrypto/rsa/rsa_oaep.c
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1/* crypto/rsa/rsa_oaep.c */
2/* Written by Ulf Moeller. This software is distributed on an "AS IS"
3 basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. */
4
5/* EME-OAEP as defined in RFC 2437 (PKCS #1 v2.0) */
6
7/* See Victor Shoup, "OAEP reconsidered," Nov. 2000,
8 * <URL: http://www.shoup.net/papers/oaep.ps.Z>
9 * for problems with the security proof for the
10 * original OAEP scheme, which EME-OAEP is based on.
11 *
12 * A new proof can be found in E. Fujisaki, T. Okamoto,
13 * D. Pointcheval, J. Stern, "RSA-OEAP is Still Alive!",
14 * Dec. 2000, <URL: http://eprint.iacr.org/2000/061/>.
15 * The new proof has stronger requirements for the
16 * underlying permutation: "partial-one-wayness" instead
17 * of one-wayness. For the RSA function, this is
18 * an equivalent notion.
19 */
20
21
22#if !defined(OPENSSL_NO_SHA) && !defined(OPENSSL_NO_SHA1)
23#include <stdio.h>
24#include "cryptlib.h"
25#include <openssl/bn.h>
26#include <openssl/rsa.h>
27#include <openssl/evp.h>
28#include <openssl/rand.h>
29#include <openssl/sha.h>
30
31int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
32 const unsigned char *from, int flen,
33 const unsigned char *param, int plen)
34 {
35 int i, emlen = tlen - 1;
36 unsigned char *db, *seed;
37 unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH];
38
39 if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1)
40 {
41 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP,
42 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
43 return 0;
44 }
45
46 if (emlen < 2 * SHA_DIGEST_LENGTH + 1)
47 {
48 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL);
49 return 0;
50 }
51
52 dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH);
53 if (dbmask == NULL)
54 {
55 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
56 return 0;
57 }
58
59 to[0] = 0;
60 seed = to + 1;
61 db = to + SHA_DIGEST_LENGTH + 1;
62
63 EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL);
64 memset(db + SHA_DIGEST_LENGTH, 0,
65 emlen - flen - 2 * SHA_DIGEST_LENGTH - 1);
66 db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01;
67 memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen);
68 if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0)
69 return 0;
70#ifdef PKCS_TESTVECT
71 memcpy(seed,
72 "\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f",
73 20);
74#endif
75
76 PKCS1_MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH,
77 EVP_sha1());
78 for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++)
79 db[i] ^= dbmask[i];
80
81 PKCS1_MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH,
82 EVP_sha1());
83 for (i = 0; i < SHA_DIGEST_LENGTH; i++)
84 seed[i] ^= seedmask[i];
85
86 OPENSSL_free(dbmask);
87 return 1;
88 }
89
90int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
91 const unsigned char *from, int flen, int num,
92 const unsigned char *param, int plen)
93 {
94 int i, dblen, mlen = -1;
95 const unsigned char *maskeddb;
96 int lzero;
97 unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
98 int bad = 0;
99
100 if (--num < 2 * SHA_DIGEST_LENGTH + 1)
101 /* 'num' is the length of the modulus, i.e. does not depend on the
102 * particular ciphertext. */
103 goto decoding_err;
104
105 lzero = num - flen;
106 if (lzero < 0)
107 {
108 /* lzero == -1 */
109
110 /* signalling this error immediately after detection might allow
111 * for side-channel attacks (e.g. timing if 'plen' is huge
112 * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal
113 * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001),
114 * so we use a 'bad' flag */
115 bad = 1;
116 lzero = 0;
117 }
118 maskeddb = from - lzero + SHA_DIGEST_LENGTH;
119
120 dblen = num - SHA_DIGEST_LENGTH;
121 db = OPENSSL_malloc(dblen);
122 if (db == NULL)
123 {
124 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
125 return -1;
126 }
127
128 PKCS1_MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen, EVP_sha1());
129 for (i = lzero; i < SHA_DIGEST_LENGTH; i++)
130 seed[i] ^= from[i - lzero];
131
132 PKCS1_MGF1(db, dblen, seed, SHA_DIGEST_LENGTH, EVP_sha1());
133 for (i = 0; i < dblen; i++)
134 db[i] ^= maskeddb[i];
135
136 EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL);
137
138 if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad)
139 goto decoding_err;
140 else
141 {
142 for (i = SHA_DIGEST_LENGTH; i < dblen; i++)
143 if (db[i] != 0x00)
144 break;
145 if (db[i] != 0x01 || i++ >= dblen)
146 goto decoding_err;
147 else
148 {
149 /* everything looks OK */
150
151 mlen = dblen - i;
152 if (tlen < mlen)
153 {
154 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE);
155 mlen = -1;
156 }
157 else
158 memcpy(to, db + i, mlen);
159 }
160 }
161 OPENSSL_free(db);
162 return mlen;
163
164decoding_err:
165 /* to avoid chosen ciphertext attacks, the error message should not reveal
166 * which kind of decoding error happened */
167 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR);
168 if (db != NULL) OPENSSL_free(db);
169 return -1;
170 }
171
172int PKCS1_MGF1(unsigned char *mask, long len,
173 const unsigned char *seed, long seedlen, const EVP_MD *dgst)
174 {
175 long i, outlen = 0;
176 unsigned char cnt[4];
177 EVP_MD_CTX c;
178 unsigned char md[EVP_MAX_MD_SIZE];
179 int mdlen;
180
181 EVP_MD_CTX_init(&c);
182 mdlen = EVP_MD_size(dgst);
183 for (i = 0; outlen < len; i++)
184 {
185 cnt[0] = (unsigned char)((i >> 24) & 255);
186 cnt[1] = (unsigned char)((i >> 16) & 255);
187 cnt[2] = (unsigned char)((i >> 8)) & 255;
188 cnt[3] = (unsigned char)(i & 255);
189 EVP_DigestInit_ex(&c,dgst, NULL);
190 EVP_DigestUpdate(&c, seed, seedlen);
191 EVP_DigestUpdate(&c, cnt, 4);
192 if (outlen + mdlen <= len)
193 {
194 EVP_DigestFinal_ex(&c, mask + outlen, NULL);
195 outlen += mdlen;
196 }
197 else
198 {
199 EVP_DigestFinal_ex(&c, md, NULL);
200 memcpy(mask + outlen, md, len - outlen);
201 outlen = len;
202 }
203 }
204 EVP_MD_CTX_cleanup(&c);
205 return 0;
206 }
207
208int MGF1(unsigned char *mask, long len, const unsigned char *seed, long seedlen)
209 {
210 return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1());
211 }
212#endif
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