Annotation of src/usr.bin/ssh/ssh-ecdsa.c, Revision 1.22
1.22 ! djm 1: /* $OpenBSD: ssh-ecdsa.c,v 1.21 2022/10/28 00:41:17 djm Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
4: * Copyright (c) 2010 Damien Miller. All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: #include <sys/types.h>
28:
29: #include <openssl/bn.h>
30: #include <openssl/ec.h>
31: #include <openssl/ecdsa.h>
32: #include <openssl/evp.h>
33:
34: #include <string.h>
35:
1.11 djm 36: #include "sshbuf.h"
37: #include "ssherr.h"
1.8 djm 38: #include "digest.h"
1.11 djm 39: #define SSHKEY_INTERNAL
40: #include "sshkey.h"
1.1 djm 41:
1.17 djm 42: static u_int
43: ssh_ecdsa_size(const struct sshkey *key)
44: {
45: switch (key->ecdsa_nid) {
46: case NID_X9_62_prime256v1:
47: return 256;
48: case NID_secp384r1:
49: return 384;
50: case NID_secp521r1:
51: return 521;
52: default:
53: return 0;
54: }
55: }
56:
57: static void
58: ssh_ecdsa_cleanup(struct sshkey *k)
59: {
60: EC_KEY_free(k->ecdsa);
61: k->ecdsa = NULL;
62: }
63:
1.18 djm 64: static int
65: ssh_ecdsa_equal(const struct sshkey *a, const struct sshkey *b)
66: {
67: const EC_GROUP *grp_a, *grp_b;
68: const EC_POINT *pub_a, *pub_b;
69:
70: if (a->ecdsa == NULL || b->ecdsa == NULL)
71: return 0;
72: if ((grp_a = EC_KEY_get0_group(a->ecdsa)) == NULL ||
73: (grp_b = EC_KEY_get0_group(b->ecdsa)) == NULL)
74: return 0;
75: if ((pub_a = EC_KEY_get0_public_key(a->ecdsa)) == NULL ||
76: (pub_b = EC_KEY_get0_public_key(b->ecdsa)) == NULL)
77: return 0;
78: if (EC_GROUP_cmp(grp_a, grp_b, NULL) != 0)
79: return 0;
80: if (EC_POINT_cmp(grp_a, pub_a, pub_b, NULL) != 0)
81: return 0;
1.19 djm 82:
1.18 djm 83: return 1;
84: }
85:
1.19 djm 86: static int
87: ssh_ecdsa_serialize_public(const struct sshkey *key, struct sshbuf *b,
1.22 ! djm 88: enum sshkey_serialize_rep opts)
1.19 djm 89: {
90: int r;
91:
92: if (key->ecdsa == NULL)
93: return SSH_ERR_INVALID_ARGUMENT;
1.22 ! djm 94: if ((r = sshbuf_put_cstring(b,
1.19 djm 95: sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 ||
96: (r = sshbuf_put_eckey(b, key->ecdsa)) != 0)
97: return r;
98:
99: return 0;
100: }
101:
1.20 djm 102: static int
103: ssh_ecdsa_generate(struct sshkey *k, int bits)
104: {
105: EC_KEY *private;
106:
107: if ((k->ecdsa_nid = sshkey_ecdsa_bits_to_nid(bits)) == -1)
108: return SSH_ERR_KEY_LENGTH;
109: if ((private = EC_KEY_new_by_curve_name(k->ecdsa_nid)) == NULL)
110: return SSH_ERR_ALLOC_FAIL;
111: if (EC_KEY_generate_key(private) != 1) {
112: EC_KEY_free(private);
113: return SSH_ERR_LIBCRYPTO_ERROR;
114: }
115: EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE);
116: k->ecdsa = private;
117: return 0;
118: }
119:
1.21 djm 120: static int
121: ssh_ecdsa_copy_public(const struct sshkey *from, struct sshkey *to)
122: {
123: to->ecdsa_nid = from->ecdsa_nid;
124: if ((to->ecdsa = EC_KEY_new_by_curve_name(from->ecdsa_nid)) == NULL)
125: return SSH_ERR_ALLOC_FAIL;
126: if (EC_KEY_set_public_key(to->ecdsa,
127: EC_KEY_get0_public_key(from->ecdsa)) != 1)
128: return SSH_ERR_LIBCRYPTO_ERROR; /* caller will free k->ecdsa */
129: return 0;
130: }
131:
1.22 ! djm 132: static int
! 133: ssh_ecdsa_deserialize_public(const char *ktype, struct sshbuf *b,
! 134: struct sshkey *key)
! 135: {
! 136: int ret = SSH_ERR_INTERNAL_ERROR;
! 137: char *curve = NULL;
! 138: EC_POINT *q = NULL;
! 139:
! 140: key->ecdsa_nid = sshkey_ecdsa_nid_from_name(ktype);
! 141: if (sshbuf_get_cstring(b, &curve, NULL) != 0) {
! 142: ret = SSH_ERR_INVALID_FORMAT;
! 143: goto out;
! 144: }
! 145: if (key->ecdsa_nid != sshkey_curve_name_to_nid(curve)) {
! 146: ret = SSH_ERR_EC_CURVE_MISMATCH;
! 147: goto out;
! 148: }
! 149: EC_KEY_free(key->ecdsa);
! 150: if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid)) == NULL) {
! 151: ret = SSH_ERR_EC_CURVE_INVALID;
! 152: goto out;
! 153: }
! 154: if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) {
! 155: ret = SSH_ERR_ALLOC_FAIL;
! 156: goto out;
! 157: }
! 158: if (sshbuf_get_ec(b, q, EC_KEY_get0_group(key->ecdsa)) != 0) {
! 159: ret = SSH_ERR_INVALID_FORMAT;
! 160: goto out;
! 161: }
! 162: if (sshkey_ec_validate_public(EC_KEY_get0_group(key->ecdsa), q) != 0) {
! 163: ret = SSH_ERR_KEY_INVALID_EC_VALUE;
! 164: goto out;
! 165: }
! 166: if (EC_KEY_set_public_key(key->ecdsa, q) != 1) {
! 167: /* XXX assume it is a allocation error */
! 168: ret = SSH_ERR_ALLOC_FAIL;
! 169: goto out;
! 170: }
! 171: #ifdef DEBUG_PK
! 172: sshkey_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q);
! 173: #endif
! 174: /* success */
! 175: ret = 0;
! 176: out:
! 177: free(curve);
! 178: EC_POINT_free(q);
! 179: return ret;
! 180: }
! 181:
1.11 djm 182: /* ARGSUSED */
1.1 djm 183: int
1.11 djm 184: ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
185: const u_char *data, size_t datalen, u_int compat)
1.1 djm 186: {
1.11 djm 187: ECDSA_SIG *sig = NULL;
1.15 djm 188: const BIGNUM *sig_r, *sig_s;
1.8 djm 189: int hash_alg;
190: u_char digest[SSH_DIGEST_MAX_LENGTH];
1.11 djm 191: size_t len, dlen;
192: struct sshbuf *b = NULL, *bb = NULL;
193: int ret = SSH_ERR_INTERNAL_ERROR;
1.1 djm 194:
1.11 djm 195: if (lenp != NULL)
196: *lenp = 0;
197: if (sigp != NULL)
198: *sigp = NULL;
199:
200: if (key == NULL || key->ecdsa == NULL ||
201: sshkey_type_plain(key->type) != KEY_ECDSA)
202: return SSH_ERR_INVALID_ARGUMENT;
203:
204: if ((hash_alg = sshkey_ec_nid_to_hash_alg(key->ecdsa_nid)) == -1 ||
205: (dlen = ssh_digest_bytes(hash_alg)) == 0)
206: return SSH_ERR_INTERNAL_ERROR;
207: if ((ret = ssh_digest_memory(hash_alg, data, datalen,
208: digest, sizeof(digest))) != 0)
209: goto out;
210:
211: if ((sig = ECDSA_do_sign(digest, dlen, key->ecdsa)) == NULL) {
212: ret = SSH_ERR_LIBCRYPTO_ERROR;
213: goto out;
214: }
215:
216: if ((bb = sshbuf_new()) == NULL || (b = sshbuf_new()) == NULL) {
217: ret = SSH_ERR_ALLOC_FAIL;
218: goto out;
219: }
1.15 djm 220: ECDSA_SIG_get0(sig, &sig_r, &sig_s);
221: if ((ret = sshbuf_put_bignum2(bb, sig_r)) != 0 ||
222: (ret = sshbuf_put_bignum2(bb, sig_s)) != 0)
1.11 djm 223: goto out;
224: if ((ret = sshbuf_put_cstring(b, sshkey_ssh_name_plain(key))) != 0 ||
225: (ret = sshbuf_put_stringb(b, bb)) != 0)
226: goto out;
227: len = sshbuf_len(b);
228: if (sigp != NULL) {
229: if ((*sigp = malloc(len)) == NULL) {
230: ret = SSH_ERR_ALLOC_FAIL;
231: goto out;
232: }
233: memcpy(*sigp, sshbuf_ptr(b), len);
1.1 djm 234: }
235: if (lenp != NULL)
236: *lenp = len;
1.11 djm 237: ret = 0;
238: out:
239: explicit_bzero(digest, sizeof(digest));
1.12 mmcc 240: sshbuf_free(b);
241: sshbuf_free(bb);
1.14 jsing 242: ECDSA_SIG_free(sig);
1.11 djm 243: return ret;
244: }
1.1 djm 245:
1.11 djm 246: /* ARGSUSED */
1.1 djm 247: int
1.11 djm 248: ssh_ecdsa_verify(const struct sshkey *key,
249: const u_char *signature, size_t signaturelen,
250: const u_char *data, size_t datalen, u_int compat)
1.1 djm 251: {
1.11 djm 252: ECDSA_SIG *sig = NULL;
1.15 djm 253: BIGNUM *sig_r = NULL, *sig_s = NULL;
1.8 djm 254: int hash_alg;
1.11 djm 255: u_char digest[SSH_DIGEST_MAX_LENGTH];
256: size_t dlen;
257: int ret = SSH_ERR_INTERNAL_ERROR;
258: struct sshbuf *b = NULL, *sigbuf = NULL;
259: char *ktype = NULL;
260:
261: if (key == NULL || key->ecdsa == NULL ||
1.13 djm 262: sshkey_type_plain(key->type) != KEY_ECDSA ||
263: signature == NULL || signaturelen == 0)
1.11 djm 264: return SSH_ERR_INVALID_ARGUMENT;
265:
266: if ((hash_alg = sshkey_ec_nid_to_hash_alg(key->ecdsa_nid)) == -1 ||
267: (dlen = ssh_digest_bytes(hash_alg)) == 0)
268: return SSH_ERR_INTERNAL_ERROR;
1.7 djm 269:
1.1 djm 270: /* fetch signature */
1.11 djm 271: if ((b = sshbuf_from(signature, signaturelen)) == NULL)
272: return SSH_ERR_ALLOC_FAIL;
273: if (sshbuf_get_cstring(b, &ktype, NULL) != 0 ||
274: sshbuf_froms(b, &sigbuf) != 0) {
275: ret = SSH_ERR_INVALID_FORMAT;
276: goto out;
277: }
278: if (strcmp(sshkey_ssh_name_plain(key), ktype) != 0) {
279: ret = SSH_ERR_KEY_TYPE_MISMATCH;
280: goto out;
281: }
282: if (sshbuf_len(b) != 0) {
283: ret = SSH_ERR_UNEXPECTED_TRAILING_DATA;
284: goto out;
1.1 djm 285: }
286:
287: /* parse signature */
1.16 djm 288: if (sshbuf_get_bignum2(sigbuf, &sig_r) != 0 ||
289: sshbuf_get_bignum2(sigbuf, &sig_s) != 0) {
290: ret = SSH_ERR_INVALID_FORMAT;
1.11 djm 291: goto out;
292: }
1.16 djm 293: if ((sig = ECDSA_SIG_new()) == NULL) {
294: ret = SSH_ERR_ALLOC_FAIL;
1.11 djm 295: goto out;
296: }
1.15 djm 297: if (!ECDSA_SIG_set0(sig, sig_r, sig_s)) {
298: ret = SSH_ERR_LIBCRYPTO_ERROR;
299: goto out;
300: }
301: sig_r = sig_s = NULL; /* transferred */
302:
1.11 djm 303: if (sshbuf_len(sigbuf) != 0) {
304: ret = SSH_ERR_UNEXPECTED_TRAILING_DATA;
305: goto out;
306: }
307: if ((ret = ssh_digest_memory(hash_alg, data, datalen,
308: digest, sizeof(digest))) != 0)
309: goto out;
310:
311: switch (ECDSA_do_verify(digest, dlen, sig, key->ecdsa)) {
312: case 1:
313: ret = 0;
314: break;
315: case 0:
316: ret = SSH_ERR_SIGNATURE_INVALID;
317: goto out;
318: default:
319: ret = SSH_ERR_LIBCRYPTO_ERROR;
320: goto out;
1.8 djm 321: }
1.1 djm 322:
1.11 djm 323: out:
1.9 djm 324: explicit_bzero(digest, sizeof(digest));
1.12 mmcc 325: sshbuf_free(sigbuf);
326: sshbuf_free(b);
1.14 jsing 327: ECDSA_SIG_free(sig);
1.15 djm 328: BN_clear_free(sig_r);
329: BN_clear_free(sig_s);
1.11 djm 330: free(ktype);
1.1 djm 331: return ret;
332: }
1.17 djm 333:
1.18 djm 334: /* NB. not static; used by ECDSA-SK */
335: const struct sshkey_impl_funcs sshkey_ecdsa_funcs = {
1.17 djm 336: /* .size = */ ssh_ecdsa_size,
337: /* .alloc = */ NULL,
338: /* .cleanup = */ ssh_ecdsa_cleanup,
1.18 djm 339: /* .equal = */ ssh_ecdsa_equal,
1.19 djm 340: /* .ssh_serialize_public = */ ssh_ecdsa_serialize_public,
1.22 ! djm 341: /* .ssh_deserialize_public = */ ssh_ecdsa_deserialize_public,
1.20 djm 342: /* .generate = */ ssh_ecdsa_generate,
1.21 djm 343: /* .copy_public = */ ssh_ecdsa_copy_public,
1.17 djm 344: };
345:
346: const struct sshkey_impl sshkey_ecdsa_nistp256_impl = {
347: /* .name = */ "ecdsa-sha2-nistp256",
348: /* .shortname = */ "ECDSA",
349: /* .sigalg = */ NULL,
350: /* .type = */ KEY_ECDSA,
351: /* .nid = */ NID_X9_62_prime256v1,
352: /* .cert = */ 0,
353: /* .sigonly = */ 0,
354: /* .keybits = */ 0,
355: /* .funcs = */ &sshkey_ecdsa_funcs,
356: };
357:
358: const struct sshkey_impl sshkey_ecdsa_nistp256_cert_impl = {
359: /* .name = */ "ecdsa-sha2-nistp256-cert-v01@openssh.com",
360: /* .shortname = */ "ECDSA-CERT",
361: /* .sigalg = */ NULL,
362: /* .type = */ KEY_ECDSA_CERT,
363: /* .nid = */ NID_X9_62_prime256v1,
364: /* .cert = */ 1,
365: /* .sigonly = */ 0,
366: /* .keybits = */ 0,
367: /* .funcs = */ &sshkey_ecdsa_funcs,
368: };
369:
370: const struct sshkey_impl sshkey_ecdsa_nistp384_impl = {
371: /* .name = */ "ecdsa-sha2-nistp384",
372: /* .shortname = */ "ECDSA",
373: /* .sigalg = */ NULL,
374: /* .type = */ KEY_ECDSA,
375: /* .nid = */ NID_secp384r1,
376: /* .cert = */ 0,
377: /* .sigonly = */ 0,
378: /* .keybits = */ 0,
379: /* .funcs = */ &sshkey_ecdsa_funcs,
380: };
381:
382: const struct sshkey_impl sshkey_ecdsa_nistp384_cert_impl = {
383: /* .name = */ "ecdsa-sha2-nistp384-cert-v01@openssh.com",
384: /* .shortname = */ "ECDSA-CERT",
385: /* .sigalg = */ NULL,
386: /* .type = */ KEY_ECDSA_CERT,
387: /* .nid = */ NID_secp384r1,
388: /* .cert = */ 1,
389: /* .sigonly = */ 0,
390: /* .keybits = */ 0,
391: /* .funcs = */ &sshkey_ecdsa_funcs,
392: };
393:
394: const struct sshkey_impl sshkey_ecdsa_nistp521_impl = {
395: /* .name = */ "ecdsa-sha2-nistp521",
396: /* .shortname = */ "ECDSA",
397: /* .sigalg = */ NULL,
398: /* .type = */ KEY_ECDSA,
399: /* .nid = */ NID_secp521r1,
400: /* .cert = */ 0,
401: /* .sigonly = */ 0,
402: /* .keybits = */ 0,
403: /* .funcs = */ &sshkey_ecdsa_funcs,
404: };
405:
406: const struct sshkey_impl sshkey_ecdsa_nistp521_cert_impl = {
407: /* .name = */ "ecdsa-sha2-nistp521-cert-v01@openssh.com",
408: /* .shortname = */ "ECDSA-CERT",
409: /* .sigalg = */ NULL,
410: /* .type = */ KEY_ECDSA_CERT,
411: /* .nid = */ NID_secp521r1,
412: /* .cert = */ 1,
413: /* .sigonly = */ 0,
414: /* .keybits = */ 0,
415: /* .funcs = */ &sshkey_ecdsa_funcs,
416: };
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-ecdsa.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh