Annotation of src/usr.bin/ssh/cipher.c, Revision 1.118
1.118 ! dtucker 1: /* $OpenBSD: cipher.c,v 1.117 2020/04/03 04:27:03 djm Exp $ */
1.1 deraadt 2: /*
1.30 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.26 markus 6: *
1.30 deraadt 7: * As far as I am concerned, the code I have written for this software
8: * can be used freely for any purpose. Any derived versions of this
9: * software must be clearly marked as such, and if the derived work is
10: * incompatible with the protocol description in the RFC file, it must be
11: * called by a name other than "ssh" or "Secure Shell".
1.26 markus 12: *
13: *
1.30 deraadt 14: * Copyright (c) 1999 Niels Provos. All rights reserved.
1.46 markus 15: * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
1.26 markus 16: *
1.30 deraadt 17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
1.26 markus 25: *
1.30 deraadt 26: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.17 deraadt 36: */
1.1 deraadt 37:
1.81 deraadt 38: #include <sys/types.h>
1.1 deraadt 39:
1.80 stevesk 40: #include <string.h>
1.81 deraadt 41: #include <stdarg.h>
1.91 djm 42: #include <stdio.h>
1.80 stevesk 43:
1.99 djm 44: #include "cipher.h"
1.91 djm 45: #include "misc.h"
1.99 djm 46: #include "sshbuf.h"
47: #include "ssherr.h"
1.95 markus 48: #include "digest.h"
1.57 markus 49:
1.113 djm 50: #ifndef WITH_OPENSSL
51: #define EVP_CIPHER_CTX void
52: #endif
1.1 deraadt 53:
1.102 djm 54: struct sshcipher_ctx {
55: int plaintext;
56: int encrypt;
57: EVP_CIPHER_CTX *evp;
1.117 djm 58: struct chachapoly_ctx *cp_ctx;
1.102 djm 59: struct aesctr_ctx ac_ctx; /* XXX union with evp? */
60: const struct sshcipher *cipher;
61: };
62:
1.99 djm 63: struct sshcipher {
1.51 markus 64: char *name;
65: u_int block_size;
66: u_int key_len;
1.85 markus 67: u_int iv_len; /* defaults to block_size */
68: u_int auth_len;
1.91 djm 69: u_int flags;
70: #define CFLAG_CBC (1<<0)
71: #define CFLAG_CHACHAPOLY (1<<1)
1.98 markus 72: #define CFLAG_AESCTR (1<<2)
73: #define CFLAG_NONE (1<<3)
1.104 djm 74: #define CFLAG_INTERNAL CFLAG_NONE /* Don't use "none" for packets */
1.98 markus 75: #ifdef WITH_OPENSSL
1.56 markus 76: const EVP_CIPHER *(*evptype)(void);
1.98 markus 77: #else
78: void *ignored;
79: #endif
1.88 djm 80: };
81:
1.99 djm 82: static const struct sshcipher ciphers[] = {
1.98 markus 83: #ifdef WITH_OPENSSL
1.107 djm 84: { "3des-cbc", 8, 24, 0, 0, CFLAG_CBC, EVP_des_ede3_cbc },
85: { "aes128-cbc", 16, 16, 0, 0, CFLAG_CBC, EVP_aes_128_cbc },
86: { "aes192-cbc", 16, 24, 0, 0, CFLAG_CBC, EVP_aes_192_cbc },
87: { "aes256-cbc", 16, 32, 0, 0, CFLAG_CBC, EVP_aes_256_cbc },
88: { "aes128-ctr", 16, 16, 0, 0, 0, EVP_aes_128_ctr },
89: { "aes192-ctr", 16, 24, 0, 0, 0, EVP_aes_192_ctr },
90: { "aes256-ctr", 16, 32, 0, 0, 0, EVP_aes_256_ctr },
1.85 markus 91: { "aes128-gcm@openssh.com",
1.107 djm 92: 16, 16, 12, 16, 0, EVP_aes_128_gcm },
1.85 markus 93: { "aes256-gcm@openssh.com",
1.107 djm 94: 16, 32, 12, 16, 0, EVP_aes_256_gcm },
1.98 markus 95: #else
1.107 djm 96: { "aes128-ctr", 16, 16, 0, 0, CFLAG_AESCTR, NULL },
97: { "aes192-ctr", 16, 24, 0, 0, CFLAG_AESCTR, NULL },
98: { "aes256-ctr", 16, 32, 0, 0, CFLAG_AESCTR, NULL },
1.98 markus 99: #endif
1.91 djm 100: { "chacha20-poly1305@openssh.com",
1.107 djm 101: 8, 64, 0, 16, CFLAG_CHACHAPOLY, NULL },
102: { "none", 8, 0, 0, 0, CFLAG_NONE, NULL },
1.47 markus 103:
1.107 djm 104: { NULL, 0, 0, 0, 0, 0, NULL }
1.32 markus 105: };
106:
107: /*--*/
1.1 deraadt 108:
1.99 djm 109: /* Returns a comma-separated list of supported ciphers. */
1.88 djm 110: char *
1.91 djm 111: cipher_alg_list(char sep, int auth_only)
1.88 djm 112: {
1.99 djm 113: char *tmp, *ret = NULL;
1.88 djm 114: size_t nlen, rlen = 0;
1.99 djm 115: const struct sshcipher *c;
1.88 djm 116:
117: for (c = ciphers; c->name != NULL; c++) {
1.104 djm 118: if ((c->flags & CFLAG_INTERNAL) != 0)
1.88 djm 119: continue;
1.91 djm 120: if (auth_only && c->auth_len == 0)
121: continue;
1.88 djm 122: if (ret != NULL)
1.90 dtucker 123: ret[rlen++] = sep;
1.88 djm 124: nlen = strlen(c->name);
1.99 djm 125: if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
126: free(ret);
127: return NULL;
128: }
129: ret = tmp;
1.88 djm 130: memcpy(ret + rlen, c->name, nlen + 1);
131: rlen += nlen;
132: }
133: return ret;
1.114 dtucker 134: }
135:
136: const char *
137: compression_alg_list(int compression)
138: {
139: #ifdef WITH_ZLIB
140: return compression ? "zlib@openssh.com,zlib,none" :
141: "none,zlib@openssh.com,zlib";
142: #else
143: return "none";
144: #endif
1.88 djm 145: }
146:
1.54 markus 147: u_int
1.99 djm 148: cipher_blocksize(const struct sshcipher *c)
1.51 markus 149: {
150: return (c->block_size);
151: }
1.60 deraadt 152:
1.54 markus 153: u_int
1.99 djm 154: cipher_keylen(const struct sshcipher *c)
1.51 markus 155: {
156: return (c->key_len);
1.94 dtucker 157: }
158:
159: u_int
1.99 djm 160: cipher_seclen(const struct sshcipher *c)
1.94 dtucker 161: {
162: if (strcmp("3des-cbc", c->name) == 0)
163: return 14;
164: return cipher_keylen(c);
1.51 markus 165: }
1.60 deraadt 166:
1.54 markus 167: u_int
1.99 djm 168: cipher_authlen(const struct sshcipher *c)
1.85 markus 169: {
170: return (c->auth_len);
171: }
172:
173: u_int
1.99 djm 174: cipher_ivlen(const struct sshcipher *c)
1.85 markus 175: {
1.91 djm 176: /*
177: * Default is cipher block size, except for chacha20+poly1305 that
178: * needs no IV. XXX make iv_len == -1 default?
179: */
180: return (c->iv_len != 0 || (c->flags & CFLAG_CHACHAPOLY) != 0) ?
181: c->iv_len : c->block_size;
1.85 markus 182: }
183:
184: u_int
1.99 djm 185: cipher_is_cbc(const struct sshcipher *c)
1.82 markus 186: {
1.91 djm 187: return (c->flags & CFLAG_CBC) != 0;
1.53 markus 188: }
1.51 markus 189:
1.41 markus 190: u_int
1.102 djm 191: cipher_ctx_is_plaintext(struct sshcipher_ctx *cc)
192: {
193: return cc->plaintext;
194: }
195:
1.99 djm 196: const struct sshcipher *
1.32 markus 197: cipher_by_name(const char *name)
198: {
1.99 djm 199: const struct sshcipher *c;
1.32 markus 200: for (c = ciphers; c->name != NULL; c++)
1.73 djm 201: if (strcmp(c->name, name) == 0)
1.32 markus 202: return c;
203: return NULL;
204: }
205:
1.24 markus 206: #define CIPHER_SEP ","
207: int
208: ciphers_valid(const char *names)
209: {
1.99 djm 210: const struct sshcipher *c;
1.69 avsm 211: char *cipher_list, *cp;
1.24 markus 212: char *p;
213:
1.27 markus 214: if (names == NULL || strcmp(names, "") == 0)
1.24 markus 215: return 0;
1.99 djm 216: if ((cipher_list = cp = strdup(names)) == NULL)
217: return 0;
1.32 markus 218: for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1.48 deraadt 219: (p = strsep(&cp, CIPHER_SEP))) {
1.32 markus 220: c = cipher_by_name(p);
1.104 djm 221: if (c == NULL || (c->flags & CFLAG_INTERNAL) != 0) {
1.89 djm 222: free(cipher_list);
1.24 markus 223: return 0;
224: }
225: }
1.89 djm 226: free(cipher_list);
1.24 markus 227: return 1;
228: }
229:
1.99 djm 230: const char *
231: cipher_warning_message(const struct sshcipher_ctx *cc)
232: {
233: if (cc == NULL || cc->cipher == NULL)
234: return NULL;
1.104 djm 235: /* XXX repurpose for CBC warning */
1.99 djm 236: return NULL;
237: }
238:
239: int
1.102 djm 240: cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
1.52 markus 241: const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
1.69 avsm 242: int do_encrypt)
1.16 markus 243: {
1.102 djm 244: struct sshcipher_ctx *cc = NULL;
245: int ret = SSH_ERR_INTERNAL_ERROR;
1.98 markus 246: #ifdef WITH_OPENSSL
1.52 markus 247: const EVP_CIPHER *type;
248: int klen;
1.102 djm 249: #endif
250:
251: *ccp = NULL;
252: if ((cc = calloc(sizeof(*cc), 1)) == NULL)
253: return SSH_ERR_ALLOC_FAIL;
1.52 markus 254:
1.105 djm 255: cc->plaintext = (cipher->flags & CFLAG_NONE) != 0;
1.85 markus 256: cc->encrypt = do_encrypt;
1.52 markus 257:
1.99 djm 258: if (keylen < cipher->key_len ||
1.102 djm 259: (iv != NULL && ivlen < cipher_ivlen(cipher))) {
260: ret = SSH_ERR_INVALID_ARGUMENT;
261: goto out;
262: }
1.99 djm 263:
1.32 markus 264: cc->cipher = cipher;
1.91 djm 265: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
1.117 djm 266: cc->cp_ctx = chachapoly_new(key, keylen);
267: ret = cc->cp_ctx != NULL ? 0 : SSH_ERR_INVALID_ARGUMENT;
1.102 djm 268: goto out;
1.91 djm 269: }
1.104 djm 270: if ((cc->cipher->flags & CFLAG_NONE) != 0) {
271: ret = 0;
272: goto out;
273: }
1.98 markus 274: #ifndef WITH_OPENSSL
275: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
276: aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
277: aesctr_ivsetup(&cc->ac_ctx, iv);
1.102 djm 278: ret = 0;
279: goto out;
280: }
281: ret = SSH_ERR_INVALID_ARGUMENT;
282: goto out;
283: #else /* WITH_OPENSSL */
1.52 markus 284: type = (*cipher->evptype)();
1.102 djm 285: if ((cc->evp = EVP_CIPHER_CTX_new()) == NULL) {
286: ret = SSH_ERR_ALLOC_FAIL;
287: goto out;
288: }
289: if (EVP_CipherInit(cc->evp, type, NULL, (u_char *)iv,
1.99 djm 290: (do_encrypt == CIPHER_ENCRYPT)) == 0) {
291: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 292: goto out;
1.99 djm 293: }
1.85 markus 294: if (cipher_authlen(cipher) &&
1.102 djm 295: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
1.99 djm 296: -1, (u_char *)iv)) {
297: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 298: goto out;
1.99 djm 299: }
1.102 djm 300: klen = EVP_CIPHER_CTX_key_length(cc->evp);
1.76 djm 301: if (klen > 0 && keylen != (u_int)klen) {
1.102 djm 302: if (EVP_CIPHER_CTX_set_key_length(cc->evp, keylen) == 0) {
1.99 djm 303: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 304: goto out;
1.99 djm 305: }
306: }
1.102 djm 307: if (EVP_CipherInit(cc->evp, NULL, (u_char *)key, NULL, -1) == 0) {
1.99 djm 308: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 309: goto out;
1.99 djm 310: }
1.102 djm 311: ret = 0;
312: #endif /* WITH_OPENSSL */
313: out:
314: if (ret == 0) {
315: /* success */
316: *ccp = cc;
317: } else {
318: if (cc != NULL) {
319: #ifdef WITH_OPENSSL
1.109 jsing 320: EVP_CIPHER_CTX_free(cc->evp);
1.102 djm 321: #endif /* WITH_OPENSSL */
1.115 jsg 322: freezero(cc, sizeof(*cc));
1.99 djm 323: }
1.74 djm 324: }
1.102 djm 325: return ret;
1.1 deraadt 326: }
1.21 markus 327:
1.83 markus 328: /*
329: * cipher_crypt() operates as following:
330: * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
1.116 djm 331: * These bytes are treated as additional authenticated data for
1.83 markus 332: * authenticated encryption modes.
333: * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
1.85 markus 334: * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
335: * This tag is written on encryption and verified on decryption.
1.83 markus 336: * Both 'aadlen' and 'authlen' can be set to 0.
337: */
1.93 markus 338: int
1.99 djm 339: cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
340: const u_char *src, u_int len, u_int aadlen, u_int authlen)
1.32 markus 341: {
1.99 djm 342: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
1.117 djm 343: return chachapoly_crypt(cc->cp_ctx, seqnr, dest, src,
1.99 djm 344: len, aadlen, authlen, cc->encrypt);
345: }
1.104 djm 346: if ((cc->cipher->flags & CFLAG_NONE) != 0) {
347: memcpy(dest, src, aadlen + len);
348: return 0;
349: }
1.98 markus 350: #ifndef WITH_OPENSSL
351: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
352: if (aadlen)
353: memcpy(dest, src, aadlen);
354: aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen,
355: dest + aadlen, len);
356: return 0;
357: }
1.99 djm 358: return SSH_ERR_INVALID_ARGUMENT;
1.98 markus 359: #else
1.85 markus 360: if (authlen) {
361: u_char lastiv[1];
362:
363: if (authlen != cipher_authlen(cc->cipher))
1.99 djm 364: return SSH_ERR_INVALID_ARGUMENT;
1.85 markus 365: /* increment IV */
1.102 djm 366: if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
1.85 markus 367: 1, lastiv))
1.99 djm 368: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 369: /* set tag on decyption */
370: if (!cc->encrypt &&
1.102 djm 371: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_TAG,
1.85 markus 372: authlen, (u_char *)src + aadlen + len))
1.99 djm 373: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 374: }
375: if (aadlen) {
376: if (authlen &&
1.102 djm 377: EVP_Cipher(cc->evp, NULL, (u_char *)src, aadlen) < 0)
1.99 djm 378: return SSH_ERR_LIBCRYPTO_ERROR;
1.83 markus 379: memcpy(dest, src, aadlen);
1.85 markus 380: }
1.32 markus 381: if (len % cc->cipher->block_size)
1.99 djm 382: return SSH_ERR_INVALID_ARGUMENT;
1.102 djm 383: if (EVP_Cipher(cc->evp, dest + aadlen, (u_char *)src + aadlen,
1.83 markus 384: len) < 0)
1.99 djm 385: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 386: if (authlen) {
387: /* compute tag (on encrypt) or verify tag (on decrypt) */
1.102 djm 388: if (EVP_Cipher(cc->evp, NULL, NULL, 0) < 0)
1.99 djm 389: return cc->encrypt ?
390: SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID;
1.85 markus 391: if (cc->encrypt &&
1.102 djm 392: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_GET_TAG,
1.85 markus 393: authlen, dest + aadlen + len))
1.99 djm 394: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 395: }
1.93 markus 396: return 0;
1.98 markus 397: #endif
1.21 markus 398: }
399:
1.91 djm 400: /* Extract the packet length, including any decryption necessary beforehand */
401: int
1.99 djm 402: cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr,
1.91 djm 403: const u_char *cp, u_int len)
404: {
405: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
1.117 djm 406: return chachapoly_get_length(cc->cp_ctx, plenp, seqnr,
1.91 djm 407: cp, len);
408: if (len < 4)
1.99 djm 409: return SSH_ERR_MESSAGE_INCOMPLETE;
1.111 markus 410: *plenp = PEEK_U32(cp);
1.91 djm 411: return 0;
412: }
413:
1.102 djm 414: void
415: cipher_free(struct sshcipher_ctx *cc)
1.16 markus 416: {
1.102 djm 417: if (cc == NULL)
418: return;
1.117 djm 419: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
420: chachapoly_free(cc->cp_ctx);
421: cc->cp_ctx = NULL;
422: } else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
1.98 markus 423: explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx));
424: #ifdef WITH_OPENSSL
1.109 jsing 425: EVP_CIPHER_CTX_free(cc->evp);
426: cc->evp = NULL;
1.98 markus 427: #endif
1.115 jsg 428: freezero(cc, sizeof(*cc));
1.52 markus 429: }
1.53 markus 430:
1.54 markus 431: /*
1.99 djm 432: * Exports an IV from the sshcipher_ctx required to export the key
1.53 markus 433: * state back from the unprivileged child to the privileged parent
434: * process.
435: */
436: int
1.99 djm 437: cipher_get_keyiv_len(const struct sshcipher_ctx *cc)
1.53 markus 438: {
1.99 djm 439: const struct sshcipher *c = cc->cipher;
1.53 markus 440:
1.104 djm 441: if ((c->flags & CFLAG_CHACHAPOLY) != 0)
442: return 0;
443: else if ((c->flags & CFLAG_AESCTR) != 0)
444: return sizeof(cc->ac_ctx.ctr);
1.98 markus 445: #ifdef WITH_OPENSSL
1.104 djm 446: return EVP_CIPHER_CTX_iv_length(cc->evp);
447: #else
448: return 0;
449: #endif
1.53 markus 450: }
451:
1.99 djm 452: int
1.112 djm 453: cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, size_t len)
1.53 markus 454: {
1.108 djm 455: #ifdef WITH_OPENSSL
1.99 djm 456: const struct sshcipher *c = cc->cipher;
1.110 djm 457: int evplen;
1.98 markus 458: #endif
1.53 markus 459:
1.91 djm 460: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
461: if (len != 0)
1.99 djm 462: return SSH_ERR_INVALID_ARGUMENT;
1.100 djm 463: return 0;
464: }
465: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
466: if (len != sizeof(cc->ac_ctx.ctr))
467: return SSH_ERR_INVALID_ARGUMENT;
468: memcpy(iv, cc->ac_ctx.ctr, len);
1.99 djm 469: return 0;
1.91 djm 470: }
1.98 markus 471: if ((cc->cipher->flags & CFLAG_NONE) != 0)
1.99 djm 472: return 0;
1.91 djm 473:
1.98 markus 474: #ifdef WITH_OPENSSL
1.104 djm 475: evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
476: if (evplen == 0)
477: return 0;
478: else if (evplen < 0)
479: return SSH_ERR_LIBCRYPTO_ERROR;
1.112 djm 480: if ((size_t)evplen != len)
1.104 djm 481: return SSH_ERR_INVALID_ARGUMENT;
482: if (cipher_authlen(c)) {
483: if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
484: len, iv))
485: return SSH_ERR_LIBCRYPTO_ERROR;
1.112 djm 486: } else if (!EVP_CIPHER_CTX_get_iv(cc->evp, iv, len))
487: return SSH_ERR_LIBCRYPTO_ERROR;
1.98 markus 488: #endif
1.99 djm 489: return 0;
1.53 markus 490: }
491:
1.99 djm 492: int
1.112 djm 493: cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv, size_t len)
1.53 markus 494: {
1.108 djm 495: #ifdef WITH_OPENSSL
1.99 djm 496: const struct sshcipher *c = cc->cipher;
1.110 djm 497: int evplen = 0;
1.98 markus 498: #endif
1.91 djm 499:
500: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
1.99 djm 501: return 0;
1.98 markus 502: if ((cc->cipher->flags & CFLAG_NONE) != 0)
1.99 djm 503: return 0;
1.53 markus 504:
1.98 markus 505: #ifdef WITH_OPENSSL
1.104 djm 506: evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
507: if (evplen <= 0)
508: return SSH_ERR_LIBCRYPTO_ERROR;
1.112 djm 509: if ((size_t)evplen != len)
510: return SSH_ERR_INVALID_ARGUMENT;
1.104 djm 511: if (cipher_authlen(c)) {
512: /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
513: if (!EVP_CIPHER_CTX_ctrl(cc->evp,
514: EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv))
1.99 djm 515: return SSH_ERR_LIBCRYPTO_ERROR;
1.112 djm 516: } else if (!EVP_CIPHER_CTX_set_iv(cc->evp, iv, evplen))
517: return SSH_ERR_LIBCRYPTO_ERROR;
1.98 markus 518: #endif
1.99 djm 519: return 0;
1.53 markus 520: }
521:
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