1 /* $OpenBSD: sshbuf-getput-crypto.c,v 1.2 2014/06/18 15:42:09 naddy Exp $ */
3 * Copyright (c) 2011 Damien Miller
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 #define SSHBUF_INTERNAL
21 #include <sys/types.h>
26 #include <openssl/bn.h>
27 #ifdef OPENSSL_HAS_ECC
28 # include <openssl/ec.h>
29 #endif /* OPENSSL_HAS_ECC */
35 sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v)
41 if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0)
43 /* Refuse negative (MSB set) bignums */
44 if ((len != 0 && (*d & 0x80) != 0))
45 return SSH_ERR_BIGNUM_IS_NEGATIVE;
46 /* Refuse overlong bignums, allow prepended \0 to avoid MSB set */
47 if (len > SSHBUF_MAX_BIGNUM + 1 ||
48 (len == SSHBUF_MAX_BIGNUM + 1 && *d != 0))
49 return SSH_ERR_BIGNUM_TOO_LARGE;
50 if (v != NULL && BN_bin2bn(d, len, v) == NULL)
51 return SSH_ERR_ALLOC_FAIL;
52 /* Consume the string */
53 if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) {
54 /* Shouldn't happen */
55 SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
57 return SSH_ERR_INTERNAL_ERROR;
63 sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v)
65 const u_char *d = sshbuf_ptr(buf);
70 if (sshbuf_len(buf) < 2)
71 return SSH_ERR_MESSAGE_INCOMPLETE;
72 len_bits = PEEK_U16(d);
73 len_bytes = (len_bits + 7) >> 3;
74 if (len_bytes > SSHBUF_MAX_BIGNUM)
75 return SSH_ERR_BIGNUM_TOO_LARGE;
76 if (sshbuf_len(buf) < 2 + len_bytes)
77 return SSH_ERR_MESSAGE_INCOMPLETE;
78 if (v != NULL && BN_bin2bn(d + 2, len_bytes, v) == NULL)
79 return SSH_ERR_ALLOC_FAIL;
80 if (sshbuf_consume(buf, 2 + len_bytes) != 0) {
81 SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
83 return SSH_ERR_INTERNAL_ERROR;
88 #ifdef OPENSSL_HAS_ECC
90 get_ec(const u_char *d, size_t len, EC_POINT *v, const EC_GROUP *g)
92 /* Refuse overlong bignums */
93 if (len == 0 || len > SSHBUF_MAX_ECPOINT)
94 return SSH_ERR_ECPOINT_TOO_LARGE;
95 /* Only handle uncompressed points */
96 if (*d != POINT_CONVERSION_UNCOMPRESSED)
97 return SSH_ERR_INVALID_FORMAT;
98 if (v != NULL && EC_POINT_oct2point(g, v, d, len, NULL) != 1)
99 return SSH_ERR_INVALID_FORMAT; /* XXX assumption */
104 sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g)
110 if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0)
112 if ((r = get_ec(d, len, v, g)) != 0)
115 if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) {
116 /* Shouldn't happen */
117 SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
119 return SSH_ERR_INTERNAL_ERROR;
125 sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v)
127 EC_POINT *pt = EC_POINT_new(EC_KEY_get0_group(v));
133 SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
134 return SSH_ERR_ALLOC_FAIL;
136 if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0) {
140 if ((r = get_ec(d, len, pt, EC_KEY_get0_group(v))) != 0) {
144 if (EC_KEY_set_public_key(v, pt) != 1) {
146 return SSH_ERR_ALLOC_FAIL; /* XXX assumption */
150 if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) {
151 /* Shouldn't happen */
152 SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
154 return SSH_ERR_INTERNAL_ERROR;
158 #endif /* OPENSSL_HAS_ECC */
161 sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v)
163 u_char d[SSHBUF_MAX_BIGNUM + 1];
164 int len = BN_num_bytes(v), prepend = 0, r;
166 if (len < 0 || len > SSHBUF_MAX_BIGNUM)
167 return SSH_ERR_INVALID_ARGUMENT;
169 if (BN_bn2bin(v, d + 1) != len)
170 return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */
171 /* If MSB is set, prepend a \0 */
172 if (len > 0 && (d[1] & 0x80) != 0)
174 if ((r = sshbuf_put_string(buf, d + 1 - prepend, len + prepend)) < 0) {
183 sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v)
185 int r, len_bits = BN_num_bits(v);
186 size_t len_bytes = (len_bits + 7) / 8;
187 u_char d[SSHBUF_MAX_BIGNUM], *dp;
189 if (len_bits < 0 || len_bytes > SSHBUF_MAX_BIGNUM)
190 return SSH_ERR_INVALID_ARGUMENT;
191 if (BN_bn2bin(v, d) != (int)len_bytes)
192 return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */
193 if ((r = sshbuf_reserve(buf, len_bytes + 2, &dp)) < 0) {
197 POKE_U16(dp, len_bits);
198 memcpy(dp + 2, d, len_bytes);
203 #ifdef OPENSSL_HAS_ECC
205 sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g)
207 u_char d[SSHBUF_MAX_ECPOINT];
212 if ((bn_ctx = BN_CTX_new()) == NULL)
213 return SSH_ERR_ALLOC_FAIL;
214 if ((len = EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED,
215 NULL, 0, bn_ctx)) > SSHBUF_MAX_ECPOINT) {
217 return SSH_ERR_INVALID_ARGUMENT;
219 if (EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED,
220 d, len, bn_ctx) != len) {
222 return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */
225 ret = sshbuf_put_string(buf, d, len);
231 sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v)
233 return sshbuf_put_ec(buf, EC_KEY_get0_public_key(v),
234 EC_KEY_get0_group(v));
236 #endif /* OPENSSL_HAS_ECC */