Annotation of src/usr.bin/ssh/cipher.c, Revision 1.116
1.116 ! djm 1: /* $OpenBSD: cipher.c,v 1.115 2020/02/26 13:40:09 jsg 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;
58: struct chachapoly_ctx cp_ctx; /* XXX union with evp? */
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 },
1.57 markus 88: { "rijndael-cbc@lysator.liu.se",
1.107 djm 89: 16, 32, 0, 0, CFLAG_CBC, EVP_aes_256_cbc },
90: { "aes128-ctr", 16, 16, 0, 0, 0, EVP_aes_128_ctr },
91: { "aes192-ctr", 16, 24, 0, 0, 0, EVP_aes_192_ctr },
92: { "aes256-ctr", 16, 32, 0, 0, 0, EVP_aes_256_ctr },
1.85 markus 93: { "aes128-gcm@openssh.com",
1.107 djm 94: 16, 16, 12, 16, 0, EVP_aes_128_gcm },
1.85 markus 95: { "aes256-gcm@openssh.com",
1.107 djm 96: 16, 32, 12, 16, 0, EVP_aes_256_gcm },
1.98 markus 97: #else
1.107 djm 98: { "aes128-ctr", 16, 16, 0, 0, CFLAG_AESCTR, NULL },
99: { "aes192-ctr", 16, 24, 0, 0, CFLAG_AESCTR, NULL },
100: { "aes256-ctr", 16, 32, 0, 0, CFLAG_AESCTR, NULL },
1.98 markus 101: #endif
1.91 djm 102: { "chacha20-poly1305@openssh.com",
1.107 djm 103: 8, 64, 0, 16, CFLAG_CHACHAPOLY, NULL },
104: { "none", 8, 0, 0, 0, CFLAG_NONE, NULL },
1.47 markus 105:
1.107 djm 106: { NULL, 0, 0, 0, 0, 0, NULL }
1.32 markus 107: };
108:
109: /*--*/
1.1 deraadt 110:
1.99 djm 111: /* Returns a comma-separated list of supported ciphers. */
1.88 djm 112: char *
1.91 djm 113: cipher_alg_list(char sep, int auth_only)
1.88 djm 114: {
1.99 djm 115: char *tmp, *ret = NULL;
1.88 djm 116: size_t nlen, rlen = 0;
1.99 djm 117: const struct sshcipher *c;
1.88 djm 118:
119: for (c = ciphers; c->name != NULL; c++) {
1.104 djm 120: if ((c->flags & CFLAG_INTERNAL) != 0)
1.88 djm 121: continue;
1.91 djm 122: if (auth_only && c->auth_len == 0)
123: continue;
1.88 djm 124: if (ret != NULL)
1.90 dtucker 125: ret[rlen++] = sep;
1.88 djm 126: nlen = strlen(c->name);
1.99 djm 127: if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
128: free(ret);
129: return NULL;
130: }
131: ret = tmp;
1.88 djm 132: memcpy(ret + rlen, c->name, nlen + 1);
133: rlen += nlen;
134: }
135: return ret;
1.114 dtucker 136: }
137:
138: const char *
139: compression_alg_list(int compression)
140: {
141: #ifdef WITH_ZLIB
142: return compression ? "zlib@openssh.com,zlib,none" :
143: "none,zlib@openssh.com,zlib";
144: #else
145: return "none";
146: #endif
1.88 djm 147: }
148:
1.54 markus 149: u_int
1.99 djm 150: cipher_blocksize(const struct sshcipher *c)
1.51 markus 151: {
152: return (c->block_size);
153: }
1.60 deraadt 154:
1.54 markus 155: u_int
1.99 djm 156: cipher_keylen(const struct sshcipher *c)
1.51 markus 157: {
158: return (c->key_len);
1.94 dtucker 159: }
160:
161: u_int
1.99 djm 162: cipher_seclen(const struct sshcipher *c)
1.94 dtucker 163: {
164: if (strcmp("3des-cbc", c->name) == 0)
165: return 14;
166: return cipher_keylen(c);
1.51 markus 167: }
1.60 deraadt 168:
1.54 markus 169: u_int
1.99 djm 170: cipher_authlen(const struct sshcipher *c)
1.85 markus 171: {
172: return (c->auth_len);
173: }
174:
175: u_int
1.99 djm 176: cipher_ivlen(const struct sshcipher *c)
1.85 markus 177: {
1.91 djm 178: /*
179: * Default is cipher block size, except for chacha20+poly1305 that
180: * needs no IV. XXX make iv_len == -1 default?
181: */
182: return (c->iv_len != 0 || (c->flags & CFLAG_CHACHAPOLY) != 0) ?
183: c->iv_len : c->block_size;
1.85 markus 184: }
185:
186: u_int
1.99 djm 187: cipher_is_cbc(const struct sshcipher *c)
1.82 markus 188: {
1.91 djm 189: return (c->flags & CFLAG_CBC) != 0;
1.53 markus 190: }
1.51 markus 191:
1.41 markus 192: u_int
1.102 djm 193: cipher_ctx_is_plaintext(struct sshcipher_ctx *cc)
194: {
195: return cc->plaintext;
196: }
197:
1.99 djm 198: const struct sshcipher *
1.32 markus 199: cipher_by_name(const char *name)
200: {
1.99 djm 201: const struct sshcipher *c;
1.32 markus 202: for (c = ciphers; c->name != NULL; c++)
1.73 djm 203: if (strcmp(c->name, name) == 0)
1.32 markus 204: return c;
205: return NULL;
206: }
207:
1.24 markus 208: #define CIPHER_SEP ","
209: int
210: ciphers_valid(const char *names)
211: {
1.99 djm 212: const struct sshcipher *c;
1.69 avsm 213: char *cipher_list, *cp;
1.24 markus 214: char *p;
215:
1.27 markus 216: if (names == NULL || strcmp(names, "") == 0)
1.24 markus 217: return 0;
1.99 djm 218: if ((cipher_list = cp = strdup(names)) == NULL)
219: return 0;
1.32 markus 220: for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1.48 deraadt 221: (p = strsep(&cp, CIPHER_SEP))) {
1.32 markus 222: c = cipher_by_name(p);
1.104 djm 223: if (c == NULL || (c->flags & CFLAG_INTERNAL) != 0) {
1.89 djm 224: free(cipher_list);
1.24 markus 225: return 0;
226: }
227: }
1.89 djm 228: free(cipher_list);
1.24 markus 229: return 1;
230: }
231:
1.99 djm 232: const char *
233: cipher_warning_message(const struct sshcipher_ctx *cc)
234: {
235: if (cc == NULL || cc->cipher == NULL)
236: return NULL;
1.104 djm 237: /* XXX repurpose for CBC warning */
1.99 djm 238: return NULL;
239: }
240:
241: int
1.102 djm 242: cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
1.52 markus 243: const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
1.69 avsm 244: int do_encrypt)
1.16 markus 245: {
1.102 djm 246: struct sshcipher_ctx *cc = NULL;
247: int ret = SSH_ERR_INTERNAL_ERROR;
1.98 markus 248: #ifdef WITH_OPENSSL
1.52 markus 249: const EVP_CIPHER *type;
250: int klen;
1.102 djm 251: #endif
252:
253: *ccp = NULL;
254: if ((cc = calloc(sizeof(*cc), 1)) == NULL)
255: return SSH_ERR_ALLOC_FAIL;
1.52 markus 256:
1.105 djm 257: cc->plaintext = (cipher->flags & CFLAG_NONE) != 0;
1.85 markus 258: cc->encrypt = do_encrypt;
1.52 markus 259:
1.99 djm 260: if (keylen < cipher->key_len ||
1.102 djm 261: (iv != NULL && ivlen < cipher_ivlen(cipher))) {
262: ret = SSH_ERR_INVALID_ARGUMENT;
263: goto out;
264: }
1.99 djm 265:
1.32 markus 266: cc->cipher = cipher;
1.91 djm 267: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
1.102 djm 268: ret = chachapoly_init(&cc->cp_ctx, key, keylen);
269: goto out;
1.91 djm 270: }
1.104 djm 271: if ((cc->cipher->flags & CFLAG_NONE) != 0) {
272: ret = 0;
273: goto out;
274: }
1.98 markus 275: #ifndef WITH_OPENSSL
276: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
277: aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
278: aesctr_ivsetup(&cc->ac_ctx, iv);
1.102 djm 279: ret = 0;
280: goto out;
281: }
282: ret = SSH_ERR_INVALID_ARGUMENT;
283: goto out;
284: #else /* WITH_OPENSSL */
1.52 markus 285: type = (*cipher->evptype)();
1.102 djm 286: if ((cc->evp = EVP_CIPHER_CTX_new()) == NULL) {
287: ret = SSH_ERR_ALLOC_FAIL;
288: goto out;
289: }
290: if (EVP_CipherInit(cc->evp, type, NULL, (u_char *)iv,
1.99 djm 291: (do_encrypt == CIPHER_ENCRYPT)) == 0) {
292: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 293: goto out;
1.99 djm 294: }
1.85 markus 295: if (cipher_authlen(cipher) &&
1.102 djm 296: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
1.99 djm 297: -1, (u_char *)iv)) {
298: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 299: goto out;
1.99 djm 300: }
1.102 djm 301: klen = EVP_CIPHER_CTX_key_length(cc->evp);
1.76 djm 302: if (klen > 0 && keylen != (u_int)klen) {
1.102 djm 303: if (EVP_CIPHER_CTX_set_key_length(cc->evp, keylen) == 0) {
1.99 djm 304: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 305: goto out;
1.99 djm 306: }
307: }
1.102 djm 308: if (EVP_CipherInit(cc->evp, NULL, (u_char *)key, NULL, -1) == 0) {
1.99 djm 309: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 310: goto out;
1.99 djm 311: }
1.102 djm 312: ret = 0;
313: #endif /* WITH_OPENSSL */
314: out:
315: if (ret == 0) {
316: /* success */
317: *ccp = cc;
318: } else {
319: if (cc != NULL) {
320: #ifdef WITH_OPENSSL
1.109 jsing 321: EVP_CIPHER_CTX_free(cc->evp);
1.102 djm 322: #endif /* WITH_OPENSSL */
1.115 jsg 323: freezero(cc, sizeof(*cc));
1.99 djm 324: }
1.74 djm 325: }
1.102 djm 326: return ret;
1.1 deraadt 327: }
1.21 markus 328:
1.83 markus 329: /*
330: * cipher_crypt() operates as following:
331: * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
1.116 ! djm 332: * These bytes are treated as additional authenticated data for
1.83 markus 333: * authenticated encryption modes.
334: * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
1.85 markus 335: * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
336: * This tag is written on encryption and verified on decryption.
1.83 markus 337: * Both 'aadlen' and 'authlen' can be set to 0.
338: */
1.93 markus 339: int
1.99 djm 340: cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
341: const u_char *src, u_int len, u_int aadlen, u_int authlen)
1.32 markus 342: {
1.99 djm 343: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
344: return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src,
345: len, aadlen, authlen, cc->encrypt);
346: }
1.104 djm 347: if ((cc->cipher->flags & CFLAG_NONE) != 0) {
348: memcpy(dest, src, aadlen + len);
349: return 0;
350: }
1.98 markus 351: #ifndef WITH_OPENSSL
352: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
353: if (aadlen)
354: memcpy(dest, src, aadlen);
355: aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen,
356: dest + aadlen, len);
357: return 0;
358: }
1.99 djm 359: return SSH_ERR_INVALID_ARGUMENT;
1.98 markus 360: #else
1.85 markus 361: if (authlen) {
362: u_char lastiv[1];
363:
364: if (authlen != cipher_authlen(cc->cipher))
1.99 djm 365: return SSH_ERR_INVALID_ARGUMENT;
1.85 markus 366: /* increment IV */
1.102 djm 367: if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
1.85 markus 368: 1, lastiv))
1.99 djm 369: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 370: /* set tag on decyption */
371: if (!cc->encrypt &&
1.102 djm 372: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_TAG,
1.85 markus 373: authlen, (u_char *)src + aadlen + len))
1.99 djm 374: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 375: }
376: if (aadlen) {
377: if (authlen &&
1.102 djm 378: EVP_Cipher(cc->evp, NULL, (u_char *)src, aadlen) < 0)
1.99 djm 379: return SSH_ERR_LIBCRYPTO_ERROR;
1.83 markus 380: memcpy(dest, src, aadlen);
1.85 markus 381: }
1.32 markus 382: if (len % cc->cipher->block_size)
1.99 djm 383: return SSH_ERR_INVALID_ARGUMENT;
1.102 djm 384: if (EVP_Cipher(cc->evp, dest + aadlen, (u_char *)src + aadlen,
1.83 markus 385: len) < 0)
1.99 djm 386: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 387: if (authlen) {
388: /* compute tag (on encrypt) or verify tag (on decrypt) */
1.102 djm 389: if (EVP_Cipher(cc->evp, NULL, NULL, 0) < 0)
1.99 djm 390: return cc->encrypt ?
391: SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID;
1.85 markus 392: if (cc->encrypt &&
1.102 djm 393: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_GET_TAG,
1.85 markus 394: authlen, dest + aadlen + len))
1.99 djm 395: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 396: }
1.93 markus 397: return 0;
1.98 markus 398: #endif
1.21 markus 399: }
400:
1.91 djm 401: /* Extract the packet length, including any decryption necessary beforehand */
402: int
1.99 djm 403: cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr,
1.91 djm 404: const u_char *cp, u_int len)
405: {
406: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
407: return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr,
408: cp, len);
409: if (len < 4)
1.99 djm 410: return SSH_ERR_MESSAGE_INCOMPLETE;
1.111 markus 411: *plenp = PEEK_U32(cp);
1.91 djm 412: return 0;
413: }
414:
1.102 djm 415: void
416: cipher_free(struct sshcipher_ctx *cc)
1.16 markus 417: {
1.102 djm 418: if (cc == NULL)
419: return;
1.91 djm 420: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
1.96 djm 421: explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx));
1.98 markus 422: else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
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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