Annotation of src/usr.bin/ssh/cipher.c, Revision 1.106
1.106 ! djm 1: /* $OpenBSD: cipher.c,v 1.105 2017/05/01 00:03:18 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:
1.1 deraadt 50:
1.102 djm 51: struct sshcipher_ctx {
52: int plaintext;
53: int encrypt;
54: EVP_CIPHER_CTX *evp;
55: struct chachapoly_ctx cp_ctx; /* XXX union with evp? */
56: struct aesctr_ctx ac_ctx; /* XXX union with evp? */
57: const struct sshcipher *cipher;
58: };
59:
1.99 djm 60: struct sshcipher {
1.51 markus 61: char *name;
62: u_int block_size;
63: u_int key_len;
1.85 markus 64: u_int iv_len; /* defaults to block_size */
65: u_int auth_len;
1.74 djm 66: u_int discard_len;
1.91 djm 67: u_int flags;
68: #define CFLAG_CBC (1<<0)
69: #define CFLAG_CHACHAPOLY (1<<1)
1.98 markus 70: #define CFLAG_AESCTR (1<<2)
71: #define CFLAG_NONE (1<<3)
1.104 djm 72: #define CFLAG_INTERNAL CFLAG_NONE /* Don't use "none" for packets */
1.98 markus 73: #ifdef WITH_OPENSSL
1.56 markus 74: const EVP_CIPHER *(*evptype)(void);
1.98 markus 75: #else
76: void *ignored;
77: #endif
1.88 djm 78: };
79:
1.99 djm 80: static const struct sshcipher ciphers[] = {
1.98 markus 81: #ifdef WITH_OPENSSL
1.104 djm 82: { "3des-cbc", 8, 24, 0, 0, 0, 1, EVP_des_ede3_cbc },
83: { "blowfish-cbc", 8, 16, 0, 0, 0, 1, EVP_bf_cbc },
84: { "cast128-cbc", 8, 16, 0, 0, 0, 1, EVP_cast5_cbc },
85: { "arcfour", 8, 16, 0, 0, 0, 0, EVP_rc4 },
86: { "arcfour128", 8, 16, 0, 0, 1536, 0, EVP_rc4 },
87: { "arcfour256", 8, 32, 0, 0, 1536, 0, EVP_rc4 },
88: { "aes128-cbc", 16, 16, 0, 0, 0, 1, EVP_aes_128_cbc },
89: { "aes192-cbc", 16, 24, 0, 0, 0, 1, EVP_aes_192_cbc },
90: { "aes256-cbc", 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc },
1.57 markus 91: { "rijndael-cbc@lysator.liu.se",
1.104 djm 92: 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc },
93: { "aes128-ctr", 16, 16, 0, 0, 0, 0, EVP_aes_128_ctr },
94: { "aes192-ctr", 16, 24, 0, 0, 0, 0, EVP_aes_192_ctr },
95: { "aes256-ctr", 16, 32, 0, 0, 0, 0, EVP_aes_256_ctr },
1.85 markus 96: { "aes128-gcm@openssh.com",
1.104 djm 97: 16, 16, 12, 16, 0, 0, EVP_aes_128_gcm },
1.85 markus 98: { "aes256-gcm@openssh.com",
1.104 djm 99: 16, 32, 12, 16, 0, 0, EVP_aes_256_gcm },
1.98 markus 100: #else
1.104 djm 101: { "aes128-ctr", 16, 16, 0, 0, 0, CFLAG_AESCTR, NULL },
102: { "aes192-ctr", 16, 24, 0, 0, 0, CFLAG_AESCTR, NULL },
103: { "aes256-ctr", 16, 32, 0, 0, 0, CFLAG_AESCTR, NULL },
1.98 markus 104: #endif
1.91 djm 105: { "chacha20-poly1305@openssh.com",
1.104 djm 106: 8, 64, 0, 16, 0, CFLAG_CHACHAPOLY, NULL },
107: { "none", 8, 0, 0, 0, 0, CFLAG_NONE, NULL },
1.47 markus 108:
1.104 djm 109: { NULL, 0, 0, 0, 0, 0, 0, NULL }
1.32 markus 110: };
111:
112: /*--*/
1.1 deraadt 113:
1.99 djm 114: /* Returns a comma-separated list of supported ciphers. */
1.88 djm 115: char *
1.91 djm 116: cipher_alg_list(char sep, int auth_only)
1.88 djm 117: {
1.99 djm 118: char *tmp, *ret = NULL;
1.88 djm 119: size_t nlen, rlen = 0;
1.99 djm 120: const struct sshcipher *c;
1.88 djm 121:
122: for (c = ciphers; c->name != NULL; c++) {
1.104 djm 123: if ((c->flags & CFLAG_INTERNAL) != 0)
1.88 djm 124: continue;
1.91 djm 125: if (auth_only && c->auth_len == 0)
126: continue;
1.88 djm 127: if (ret != NULL)
1.90 dtucker 128: ret[rlen++] = sep;
1.88 djm 129: nlen = strlen(c->name);
1.99 djm 130: if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
131: free(ret);
132: return NULL;
133: }
134: ret = tmp;
1.88 djm 135: memcpy(ret + rlen, c->name, nlen + 1);
136: rlen += nlen;
137: }
138: return ret;
139: }
140:
1.54 markus 141: u_int
1.99 djm 142: cipher_blocksize(const struct sshcipher *c)
1.51 markus 143: {
144: return (c->block_size);
145: }
1.60 deraadt 146:
1.54 markus 147: u_int
1.99 djm 148: cipher_keylen(const struct sshcipher *c)
1.51 markus 149: {
150: return (c->key_len);
1.94 dtucker 151: }
152:
153: u_int
1.99 djm 154: cipher_seclen(const struct sshcipher *c)
1.94 dtucker 155: {
156: if (strcmp("3des-cbc", c->name) == 0)
157: return 14;
158: return cipher_keylen(c);
1.51 markus 159: }
1.60 deraadt 160:
1.54 markus 161: u_int
1.99 djm 162: cipher_authlen(const struct sshcipher *c)
1.85 markus 163: {
164: return (c->auth_len);
165: }
166:
167: u_int
1.99 djm 168: cipher_ivlen(const struct sshcipher *c)
1.85 markus 169: {
1.91 djm 170: /*
171: * Default is cipher block size, except for chacha20+poly1305 that
172: * needs no IV. XXX make iv_len == -1 default?
173: */
174: return (c->iv_len != 0 || (c->flags & CFLAG_CHACHAPOLY) != 0) ?
175: c->iv_len : c->block_size;
1.85 markus 176: }
177:
178: u_int
1.99 djm 179: cipher_is_cbc(const struct sshcipher *c)
1.82 markus 180: {
1.91 djm 181: return (c->flags & CFLAG_CBC) != 0;
1.53 markus 182: }
1.51 markus 183:
1.41 markus 184: u_int
1.102 djm 185: cipher_ctx_is_plaintext(struct sshcipher_ctx *cc)
186: {
187: return cc->plaintext;
188: }
189:
1.99 djm 190: const struct sshcipher *
1.32 markus 191: cipher_by_name(const char *name)
192: {
1.99 djm 193: const struct sshcipher *c;
1.32 markus 194: for (c = ciphers; c->name != NULL; c++)
1.73 djm 195: if (strcmp(c->name, name) == 0)
1.32 markus 196: return c;
197: return NULL;
198: }
199:
1.24 markus 200: #define CIPHER_SEP ","
201: int
202: ciphers_valid(const char *names)
203: {
1.99 djm 204: const struct sshcipher *c;
1.69 avsm 205: char *cipher_list, *cp;
1.24 markus 206: char *p;
207:
1.27 markus 208: if (names == NULL || strcmp(names, "") == 0)
1.24 markus 209: return 0;
1.99 djm 210: if ((cipher_list = cp = strdup(names)) == NULL)
211: return 0;
1.32 markus 212: for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1.48 deraadt 213: (p = strsep(&cp, CIPHER_SEP))) {
1.32 markus 214: c = cipher_by_name(p);
1.104 djm 215: if (c == NULL || (c->flags & CFLAG_INTERNAL) != 0) {
1.89 djm 216: free(cipher_list);
1.24 markus 217: return 0;
218: }
219: }
1.89 djm 220: free(cipher_list);
1.24 markus 221: return 1;
222: }
223:
1.99 djm 224: const char *
225: cipher_warning_message(const struct sshcipher_ctx *cc)
226: {
227: if (cc == NULL || cc->cipher == NULL)
228: return NULL;
1.104 djm 229: /* XXX repurpose for CBC warning */
1.99 djm 230: return NULL;
231: }
232:
233: int
1.102 djm 234: cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
1.52 markus 235: const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
1.69 avsm 236: int do_encrypt)
1.16 markus 237: {
1.102 djm 238: struct sshcipher_ctx *cc = NULL;
239: int ret = SSH_ERR_INTERNAL_ERROR;
1.98 markus 240: #ifdef WITH_OPENSSL
1.52 markus 241: const EVP_CIPHER *type;
242: int klen;
1.74 djm 243: u_char *junk, *discard;
1.102 djm 244: #endif
245:
246: *ccp = NULL;
247: if ((cc = calloc(sizeof(*cc), 1)) == NULL)
248: return SSH_ERR_ALLOC_FAIL;
1.52 markus 249:
1.105 djm 250: cc->plaintext = (cipher->flags & CFLAG_NONE) != 0;
1.85 markus 251: cc->encrypt = do_encrypt;
1.52 markus 252:
1.99 djm 253: if (keylen < cipher->key_len ||
1.102 djm 254: (iv != NULL && ivlen < cipher_ivlen(cipher))) {
255: ret = SSH_ERR_INVALID_ARGUMENT;
256: goto out;
257: }
1.99 djm 258:
1.32 markus 259: cc->cipher = cipher;
1.91 djm 260: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
1.102 djm 261: ret = chachapoly_init(&cc->cp_ctx, key, keylen);
262: goto out;
1.91 djm 263: }
1.104 djm 264: if ((cc->cipher->flags & CFLAG_NONE) != 0) {
265: ret = 0;
266: goto out;
267: }
1.98 markus 268: #ifndef WITH_OPENSSL
269: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
270: aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
271: aesctr_ivsetup(&cc->ac_ctx, iv);
1.102 djm 272: ret = 0;
273: goto out;
274: }
275: ret = SSH_ERR_INVALID_ARGUMENT;
276: goto out;
277: #else /* WITH_OPENSSL */
1.52 markus 278: type = (*cipher->evptype)();
1.102 djm 279: if ((cc->evp = EVP_CIPHER_CTX_new()) == NULL) {
280: ret = SSH_ERR_ALLOC_FAIL;
281: goto out;
282: }
283: if (EVP_CipherInit(cc->evp, type, NULL, (u_char *)iv,
1.99 djm 284: (do_encrypt == CIPHER_ENCRYPT)) == 0) {
285: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 286: goto out;
1.99 djm 287: }
1.85 markus 288: if (cipher_authlen(cipher) &&
1.102 djm 289: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
1.99 djm 290: -1, (u_char *)iv)) {
291: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 292: goto out;
1.99 djm 293: }
1.102 djm 294: klen = EVP_CIPHER_CTX_key_length(cc->evp);
1.76 djm 295: if (klen > 0 && keylen != (u_int)klen) {
1.102 djm 296: if (EVP_CIPHER_CTX_set_key_length(cc->evp, keylen) == 0) {
1.99 djm 297: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 298: goto out;
1.99 djm 299: }
300: }
1.102 djm 301: if (EVP_CipherInit(cc->evp, NULL, (u_char *)key, NULL, -1) == 0) {
1.99 djm 302: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 303: goto out;
1.99 djm 304: }
1.74 djm 305:
1.77 djm 306: if (cipher->discard_len > 0) {
1.99 djm 307: if ((junk = malloc(cipher->discard_len)) == NULL ||
308: (discard = malloc(cipher->discard_len)) == NULL) {
1.101 mmcc 309: free(junk);
1.99 djm 310: ret = SSH_ERR_ALLOC_FAIL;
1.102 djm 311: goto out;
1.99 djm 312: }
1.102 djm 313: ret = EVP_Cipher(cc->evp, discard, junk, cipher->discard_len);
1.96 djm 314: explicit_bzero(discard, cipher->discard_len);
1.89 djm 315: free(junk);
316: free(discard);
1.99 djm 317: if (ret != 1) {
318: ret = SSH_ERR_LIBCRYPTO_ERROR;
1.102 djm 319: goto out;
320: }
321: }
322: ret = 0;
323: #endif /* WITH_OPENSSL */
324: out:
325: if (ret == 0) {
326: /* success */
327: *ccp = cc;
328: } else {
329: if (cc != NULL) {
330: #ifdef WITH_OPENSSL
331: if (cc->evp != NULL)
332: EVP_CIPHER_CTX_free(cc->evp);
333: #endif /* WITH_OPENSSL */
334: explicit_bzero(cc, sizeof(*cc));
335: free(cc);
1.99 djm 336: }
1.74 djm 337: }
1.102 djm 338: return ret;
1.1 deraadt 339: }
1.21 markus 340:
1.83 markus 341: /*
342: * cipher_crypt() operates as following:
343: * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
344: * Theses bytes are treated as additional authenticated data for
345: * authenticated encryption modes.
346: * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
1.85 markus 347: * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
348: * This tag is written on encryption and verified on decryption.
1.83 markus 349: * Both 'aadlen' and 'authlen' can be set to 0.
350: */
1.93 markus 351: int
1.99 djm 352: cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
353: const u_char *src, u_int len, u_int aadlen, u_int authlen)
1.32 markus 354: {
1.99 djm 355: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
356: return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src,
357: len, aadlen, authlen, cc->encrypt);
358: }
1.104 djm 359: if ((cc->cipher->flags & CFLAG_NONE) != 0) {
360: memcpy(dest, src, aadlen + len);
361: return 0;
362: }
1.98 markus 363: #ifndef WITH_OPENSSL
364: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
365: if (aadlen)
366: memcpy(dest, src, aadlen);
367: aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen,
368: dest + aadlen, len);
369: return 0;
370: }
1.99 djm 371: return SSH_ERR_INVALID_ARGUMENT;
1.98 markus 372: #else
1.85 markus 373: if (authlen) {
374: u_char lastiv[1];
375:
376: if (authlen != cipher_authlen(cc->cipher))
1.99 djm 377: return SSH_ERR_INVALID_ARGUMENT;
1.85 markus 378: /* increment IV */
1.102 djm 379: if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
1.85 markus 380: 1, lastiv))
1.99 djm 381: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 382: /* set tag on decyption */
383: if (!cc->encrypt &&
1.102 djm 384: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_TAG,
1.85 markus 385: authlen, (u_char *)src + aadlen + len))
1.99 djm 386: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 387: }
388: if (aadlen) {
389: if (authlen &&
1.102 djm 390: EVP_Cipher(cc->evp, NULL, (u_char *)src, aadlen) < 0)
1.99 djm 391: return SSH_ERR_LIBCRYPTO_ERROR;
1.83 markus 392: memcpy(dest, src, aadlen);
1.85 markus 393: }
1.32 markus 394: if (len % cc->cipher->block_size)
1.99 djm 395: return SSH_ERR_INVALID_ARGUMENT;
1.102 djm 396: if (EVP_Cipher(cc->evp, dest + aadlen, (u_char *)src + aadlen,
1.83 markus 397: len) < 0)
1.99 djm 398: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 399: if (authlen) {
400: /* compute tag (on encrypt) or verify tag (on decrypt) */
1.102 djm 401: if (EVP_Cipher(cc->evp, NULL, NULL, 0) < 0)
1.99 djm 402: return cc->encrypt ?
403: SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID;
1.85 markus 404: if (cc->encrypt &&
1.102 djm 405: !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_GET_TAG,
1.85 markus 406: authlen, dest + aadlen + len))
1.99 djm 407: return SSH_ERR_LIBCRYPTO_ERROR;
1.85 markus 408: }
1.93 markus 409: return 0;
1.98 markus 410: #endif
1.21 markus 411: }
412:
1.91 djm 413: /* Extract the packet length, including any decryption necessary beforehand */
414: int
1.99 djm 415: cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr,
1.91 djm 416: const u_char *cp, u_int len)
417: {
418: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
419: return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr,
420: cp, len);
421: if (len < 4)
1.99 djm 422: return SSH_ERR_MESSAGE_INCOMPLETE;
1.91 djm 423: *plenp = get_u32(cp);
424: return 0;
425: }
426:
1.102 djm 427: void
428: cipher_free(struct sshcipher_ctx *cc)
1.16 markus 429: {
1.102 djm 430: if (cc == NULL)
431: return;
1.91 djm 432: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
1.96 djm 433: explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx));
1.98 markus 434: else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
435: explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx));
436: #ifdef WITH_OPENSSL
1.102 djm 437: if (cc->evp != NULL) {
438: EVP_CIPHER_CTX_free(cc->evp);
439: cc->evp = NULL;
440: }
1.98 markus 441: #endif
1.102 djm 442: explicit_bzero(cc, sizeof(*cc));
443: free(cc);
1.52 markus 444: }
1.53 markus 445:
1.54 markus 446: /*
1.99 djm 447: * Exports an IV from the sshcipher_ctx required to export the key
1.53 markus 448: * state back from the unprivileged child to the privileged parent
449: * process.
450: */
451: int
1.99 djm 452: cipher_get_keyiv_len(const struct sshcipher_ctx *cc)
1.53 markus 453: {
1.99 djm 454: const struct sshcipher *c = cc->cipher;
1.53 markus 455:
1.104 djm 456: if ((c->flags & CFLAG_CHACHAPOLY) != 0)
457: return 0;
458: else if ((c->flags & CFLAG_AESCTR) != 0)
459: return sizeof(cc->ac_ctx.ctr);
1.98 markus 460: #ifdef WITH_OPENSSL
1.104 djm 461: return EVP_CIPHER_CTX_iv_length(cc->evp);
462: #else
463: return 0;
464: #endif
1.53 markus 465: }
466:
1.99 djm 467: int
468: cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, u_int len)
1.53 markus 469: {
1.99 djm 470: const struct sshcipher *c = cc->cipher;
1.98 markus 471: #ifdef WITH_OPENSSL
1.99 djm 472: int evplen;
1.98 markus 473: #endif
1.53 markus 474:
1.91 djm 475: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
476: if (len != 0)
1.99 djm 477: return SSH_ERR_INVALID_ARGUMENT;
1.100 djm 478: return 0;
479: }
480: if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
481: if (len != sizeof(cc->ac_ctx.ctr))
482: return SSH_ERR_INVALID_ARGUMENT;
483: memcpy(iv, cc->ac_ctx.ctr, len);
1.99 djm 484: return 0;
1.91 djm 485: }
1.98 markus 486: if ((cc->cipher->flags & CFLAG_NONE) != 0)
1.99 djm 487: return 0;
1.91 djm 488:
1.98 markus 489: #ifdef WITH_OPENSSL
1.104 djm 490: evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
491: if (evplen == 0)
492: return 0;
493: else if (evplen < 0)
494: return SSH_ERR_LIBCRYPTO_ERROR;
495: if ((u_int)evplen != len)
496: return SSH_ERR_INVALID_ARGUMENT;
497: if (cipher_authlen(c)) {
498: if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
499: len, iv))
500: return SSH_ERR_LIBCRYPTO_ERROR;
501: } else
502: memcpy(iv, cc->evp->iv, len);
1.98 markus 503: #endif
1.99 djm 504: return 0;
1.53 markus 505: }
506:
1.99 djm 507: int
508: cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv)
1.53 markus 509: {
1.99 djm 510: const struct sshcipher *c = cc->cipher;
1.98 markus 511: #ifdef WITH_OPENSSL
1.99 djm 512: int evplen = 0;
1.98 markus 513: #endif
1.91 djm 514:
515: if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
1.99 djm 516: return 0;
1.98 markus 517: if ((cc->cipher->flags & CFLAG_NONE) != 0)
1.99 djm 518: return 0;
1.53 markus 519:
1.98 markus 520: #ifdef WITH_OPENSSL
1.104 djm 521: evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
522: if (evplen <= 0)
523: return SSH_ERR_LIBCRYPTO_ERROR;
524: if (cipher_authlen(c)) {
525: /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
526: if (!EVP_CIPHER_CTX_ctrl(cc->evp,
527: EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv))
1.99 djm 528: return SSH_ERR_LIBCRYPTO_ERROR;
1.104 djm 529: } else
530: memcpy(cc->evp->iv, iv, evplen);
1.98 markus 531: #endif
1.99 djm 532: return 0;
1.53 markus 533: }
534:
1.98 markus 535: #ifdef WITH_OPENSSL
1.102 djm 536: #define EVP_X_STATE(evp) (evp)->cipher_data
537: #define EVP_X_STATE_LEN(evp) (evp)->cipher->ctx_size
1.98 markus 538: #endif
1.53 markus 539:
540: int
1.99 djm 541: cipher_get_keycontext(const struct sshcipher_ctx *cc, u_char *dat)
1.53 markus 542: {
1.98 markus 543: #ifdef WITH_OPENSSL
1.99 djm 544: const struct sshcipher *c = cc->cipher;
1.59 markus 545: int plen = 0;
1.53 markus 546:
1.87 djm 547: if (c->evptype == EVP_rc4) {
1.59 markus 548: plen = EVP_X_STATE_LEN(cc->evp);
1.53 markus 549: if (dat == NULL)
1.59 markus 550: return (plen);
551: memcpy(dat, EVP_X_STATE(cc->evp), plen);
1.53 markus 552: }
553: return (plen);
1.98 markus 554: #else
1.99 djm 555: return 0;
1.98 markus 556: #endif
1.53 markus 557: }
558:
559: void
1.99 djm 560: cipher_set_keycontext(struct sshcipher_ctx *cc, const u_char *dat)
1.53 markus 561: {
1.98 markus 562: #ifdef WITH_OPENSSL
1.99 djm 563: const struct sshcipher *c = cc->cipher;
1.53 markus 564: int plen;
565:
1.87 djm 566: if (c->evptype == EVP_rc4) {
1.53 markus 567: plen = EVP_X_STATE_LEN(cc->evp);
568: memcpy(EVP_X_STATE(cc->evp), dat, plen);
569: }
1.98 markus 570: #endif
1.1 deraadt 571: }
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