Annotation of src/usr.bin/ssh/dh.c, Revision 1.73
1.73 ! dtucker 1: /* $OpenBSD: dh.c,v 1.72 2020/10/18 11:32:01 djm Exp $ */
1.1 provos 2: /*
3: * Copyright (c) 2000 Niels Provos. All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: *
14: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24: */
1.39 stevesk 25:
1.71 djm 26: #include <errno.h>
1.70 djm 27: #include <stdio.h>
28: #include <stdlib.h>
29: #include <string.h>
30: #include <limits.h>
1.1 provos 31:
32: #include <openssl/bn.h>
33: #include <openssl/dh.h>
1.38 stevesk 34:
1.1 provos 35: #include "dh.h"
1.5 markus 36: #include "pathnames.h"
1.6 markus 37: #include "log.h"
38: #include "misc.h"
1.54 markus 39: #include "ssherr.h"
1.1 provos 40:
1.73 ! dtucker 41: static const char *moduli_filename;
! 42:
! 43: void dh_set_moduli_file(const char *filename)
! 44: {
! 45: moduli_filename = filename;
! 46: }
! 47:
! 48: static const char * get_moduli_filename(void)
! 49: {
! 50: return moduli_filename ? moduli_filename : _PATH_DH_MODULI;
! 51: }
! 52:
1.17 itojun 53: static int
1.1 provos 54: parse_prime(int linenum, char *line, struct dhgroup *dhg)
55: {
56: char *cp, *arg;
57: char *strsize, *gen, *prime;
1.35 deraadt 58: const char *errstr = NULL;
1.47 djm 59: long long n;
1.1 provos 60:
1.51 markus 61: dhg->p = dhg->g = NULL;
1.1 provos 62: cp = line;
1.32 djm 63: if ((arg = strdelim(&cp)) == NULL)
64: return 0;
1.1 provos 65: /* Ignore leading whitespace */
66: if (*arg == '\0')
67: arg = strdelim(&cp);
1.22 markus 68: if (!arg || !*arg || *arg == '#')
1.1 provos 69: return 0;
70:
71: /* time */
72: if (cp == NULL || *arg == '\0')
1.50 djm 73: goto truncated;
1.1 provos 74: arg = strsep(&cp, " "); /* type */
75: if (cp == NULL || *arg == '\0')
1.50 djm 76: goto truncated;
1.47 djm 77: /* Ensure this is a safe prime */
78: n = strtonum(arg, 0, 5, &errstr);
1.50 djm 79: if (errstr != NULL || n != MODULI_TYPE_SAFE) {
80: error("moduli:%d: type is not %d", linenum, MODULI_TYPE_SAFE);
1.47 djm 81: goto fail;
1.50 djm 82: }
1.1 provos 83: arg = strsep(&cp, " "); /* tests */
84: if (cp == NULL || *arg == '\0')
1.50 djm 85: goto truncated;
1.47 djm 86: /* Ensure prime has been tested and is not composite */
87: n = strtonum(arg, 0, 0x1f, &errstr);
88: if (errstr != NULL ||
1.50 djm 89: (n & MODULI_TESTS_COMPOSITE) || !(n & ~MODULI_TESTS_COMPOSITE)) {
90: error("moduli:%d: invalid moduli tests flag", linenum);
1.47 djm 91: goto fail;
1.50 djm 92: }
1.1 provos 93: arg = strsep(&cp, " "); /* tries */
94: if (cp == NULL || *arg == '\0')
1.50 djm 95: goto truncated;
1.47 djm 96: n = strtonum(arg, 0, 1<<30, &errstr);
1.50 djm 97: if (errstr != NULL || n == 0) {
98: error("moduli:%d: invalid primality trial count", linenum);
1.1 provos 99: goto fail;
1.50 djm 100: }
1.1 provos 101: strsize = strsep(&cp, " "); /* size */
102: if (cp == NULL || *strsize == '\0' ||
1.48 grunk 103: (dhg->size = (int)strtonum(strsize, 0, 64*1024, &errstr)) == 0 ||
1.50 djm 104: errstr) {
105: error("moduli:%d: invalid prime length", linenum);
1.1 provos 106: goto fail;
1.50 djm 107: }
1.9 provos 108: /* The whole group is one bit larger */
109: dhg->size++;
1.1 provos 110: gen = strsep(&cp, " "); /* gen */
111: if (cp == NULL || *gen == '\0')
1.50 djm 112: goto truncated;
1.1 provos 113: prime = strsep(&cp, " "); /* prime */
1.50 djm 114: if (cp != NULL || *prime == '\0') {
115: truncated:
116: error("moduli:%d: truncated", linenum);
1.1 provos 117: goto fail;
1.50 djm 118: }
1.1 provos 119:
1.54 markus 120: if ((dhg->g = BN_new()) == NULL ||
121: (dhg->p = BN_new()) == NULL) {
122: error("parse_prime: BN_new failed");
123: goto fail;
124: }
1.50 djm 125: if (BN_hex2bn(&dhg->g, gen) == 0) {
126: error("moduli:%d: could not parse generator value", linenum);
127: goto fail;
128: }
129: if (BN_hex2bn(&dhg->p, prime) == 0) {
130: error("moduli:%d: could not parse prime value", linenum);
131: goto fail;
132: }
133: if (BN_num_bits(dhg->p) != dhg->size) {
134: error("moduli:%d: prime has wrong size: actual %d listed %d",
135: linenum, BN_num_bits(dhg->p), dhg->size - 1);
136: goto fail;
137: }
138: if (BN_cmp(dhg->g, BN_value_one()) <= 0) {
139: error("moduli:%d: generator is invalid", linenum);
140: goto fail;
141: }
142: return 1;
1.10 provos 143:
1.1 provos 144: fail:
1.63 jsing 145: BN_clear_free(dhg->g);
146: BN_clear_free(dhg->p);
1.50 djm 147: dhg->g = dhg->p = NULL;
148: return 0;
1.1 provos 149: }
150:
151: DH *
1.9 provos 152: choose_dh(int min, int wantbits, int max)
1.1 provos 153: {
154: FILE *f;
1.64 markus 155: char *line = NULL;
156: size_t linesize = 0;
157: int best, bestcount, which, linenum;
1.1 provos 158: struct dhgroup dhg;
159:
1.73 ! dtucker 160: if ((f = fopen(get_moduli_filename(), "r")) == NULL) {
1.62 dtucker 161: logit("WARNING: could not open %s (%s), using fixed modulus",
1.73 ! dtucker 162: get_moduli_filename(), strerror(errno));
1.57 dtucker 163: return (dh_new_group_fallback(max));
1.1 provos 164: }
165:
166: linenum = 0;
167: best = bestcount = 0;
1.64 markus 168: while (getline(&line, &linesize, f) != -1) {
1.1 provos 169: linenum++;
170: if (!parse_prime(linenum, line, &dhg))
171: continue;
1.19 markus 172: BN_clear_free(dhg.g);
173: BN_clear_free(dhg.p);
1.1 provos 174:
1.9 provos 175: if (dhg.size > max || dhg.size < min)
176: continue;
177:
178: if ((dhg.size > wantbits && dhg.size < best) ||
179: (dhg.size > best && best < wantbits)) {
1.1 provos 180: best = dhg.size;
181: bestcount = 0;
182: }
183: if (dhg.size == best)
184: bestcount++;
185: }
1.64 markus 186: free(line);
187: line = NULL;
188: linesize = 0;
1.16 provos 189: rewind(f);
1.1 provos 190:
191: if (bestcount == 0) {
1.16 provos 192: fclose(f);
1.73 ! dtucker 193: logit("WARNING: no suitable primes in %s",
! 194: get_moduli_filename());
1.57 dtucker 195: return (dh_new_group_fallback(max));
1.1 provos 196: }
1.68 millert 197: which = arc4random_uniform(bestcount);
1.1 provos 198:
199: linenum = 0;
1.68 millert 200: bestcount = 0;
1.64 markus 201: while (getline(&line, &linesize, f) != -1) {
1.68 millert 202: linenum++;
1.1 provos 203: if (!parse_prime(linenum, line, &dhg))
1.9 provos 204: continue;
1.13 markus 205: if ((dhg.size > max || dhg.size < min) ||
206: dhg.size != best ||
1.68 millert 207: bestcount++ != which) {
1.19 markus 208: BN_clear_free(dhg.g);
209: BN_clear_free(dhg.p);
1.1 provos 210: continue;
211: }
212: break;
213: }
1.64 markus 214: free(line);
215: line = NULL;
1.1 provos 216: fclose(f);
1.68 millert 217: if (bestcount != which + 1) {
218: logit("WARNING: selected prime disappeared in %s, giving up",
1.73 ! dtucker 219: get_moduli_filename());
1.57 dtucker 220: return (dh_new_group_fallback(max));
1.54 markus 221: }
1.1 provos 222:
223: return (dh_new_group(dhg.g, dhg.p));
1.11 markus 224: }
225:
1.30 djm 226: /* diffie-hellman-groupN-sha1 */
1.11 markus 227:
228: int
1.67 djm 229: dh_pub_is_valid(const DH *dh, const BIGNUM *dh_pub)
1.11 markus 230: {
231: int i;
232: int n = BN_num_bits(dh_pub);
233: int bits_set = 0;
1.36 djm 234: BIGNUM *tmp;
1.67 djm 235: const BIGNUM *dh_p;
1.11 markus 236:
1.67 djm 237: DH_get0_pqg(dh, &dh_p, NULL, NULL);
238:
239: if (BN_is_negative(dh_pub)) {
1.45 ray 240: logit("invalid public DH value: negative");
1.11 markus 241: return 0;
242: }
1.36 djm 243: if (BN_cmp(dh_pub, BN_value_one()) != 1) { /* pub_exp <= 1 */
244: logit("invalid public DH value: <= 1");
245: return 0;
246: }
247:
1.45 ray 248: if ((tmp = BN_new()) == NULL) {
1.72 djm 249: error_f("BN_new failed");
1.45 ray 250: return 0;
251: }
1.67 djm 252: if (!BN_sub(tmp, dh_p, BN_value_one()) ||
1.36 djm 253: BN_cmp(dh_pub, tmp) != -1) { /* pub_exp > p-2 */
254: BN_clear_free(tmp);
255: logit("invalid public DH value: >= p-1");
256: return 0;
257: }
258: BN_clear_free(tmp);
259:
1.11 markus 260: for (i = 0; i <= n; i++)
261: if (BN_is_bit_set(dh_pub, i))
262: bits_set++;
1.67 djm 263: debug2("bits set: %d/%d", bits_set, BN_num_bits(dh_p));
1.11 markus 264:
1.58 djm 265: /*
266: * if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial
267: */
268: if (bits_set < 4) {
269: logit("invalid public DH value (%d/%d)",
1.67 djm 270: bits_set, BN_num_bits(dh_p));
1.58 djm 271: return 0;
272: }
273: return 1;
1.11 markus 274: }
275:
1.54 markus 276: int
1.11 markus 277: dh_gen_key(DH *dh, int need)
278: {
1.53 djm 279: int pbits;
1.67 djm 280: const BIGNUM *dh_p, *pub_key;
281:
282: DH_get0_pqg(dh, &dh_p, NULL, NULL);
1.11 markus 283:
1.67 djm 284: if (need < 0 || dh_p == NULL ||
285: (pbits = BN_num_bits(dh_p)) <= 0 ||
1.56 djm 286: need > INT_MAX / 2 || 2 * need > pbits)
1.54 markus 287: return SSH_ERR_INVALID_ARGUMENT;
1.58 djm 288: if (need < 256)
289: need = 256;
290: /*
291: * Pollard Rho, Big step/Little Step attacks are O(sqrt(n)),
292: * so double requested need here.
293: */
1.67 djm 294: if (!DH_set_length(dh, MINIMUM(need * 2, pbits - 1)))
295: return SSH_ERR_LIBCRYPTO_ERROR;
296:
297: if (DH_generate_key(dh) == 0)
1.54 markus 298: return SSH_ERR_LIBCRYPTO_ERROR;
1.67 djm 299: DH_get0_key(dh, &pub_key, NULL);
300: if (!dh_pub_is_valid(dh, pub_key))
301: return SSH_ERR_INVALID_FORMAT;
1.54 markus 302: return 0;
1.11 markus 303: }
304:
305: DH *
306: dh_new_group_asc(const char *gen, const char *modulus)
307: {
308: DH *dh;
1.67 djm 309: BIGNUM *dh_p = NULL, *dh_g = NULL;
1.11 markus 310:
1.18 markus 311: if ((dh = DH_new()) == NULL)
1.54 markus 312: return NULL;
1.67 djm 313: if (BN_hex2bn(&dh_p, modulus) == 0 ||
314: BN_hex2bn(&dh_g, gen) == 0)
315: goto fail;
316: if (!DH_set0_pqg(dh, dh_p, NULL, dh_g))
317: goto fail;
318: return dh;
319: fail:
320: DH_free(dh);
321: BN_clear_free(dh_p);
322: BN_clear_free(dh_g);
323: return NULL;
1.11 markus 324: }
325:
326: /*
327: * This just returns the group, we still need to generate the exchange
328: * value.
329: */
330: DH *
331: dh_new_group(BIGNUM *gen, BIGNUM *modulus)
332: {
333: DH *dh;
334:
1.18 markus 335: if ((dh = DH_new()) == NULL)
1.54 markus 336: return NULL;
1.67 djm 337: if (!DH_set0_pqg(dh, modulus, NULL, gen)) {
338: DH_free(dh);
339: return NULL;
340: }
1.11 markus 341:
1.67 djm 342: return dh;
1.11 markus 343: }
344:
1.60 djm 345: /* rfc2409 "Second Oakley Group" (1024 bits) */
1.11 markus 346: DH *
347: dh_new_group1(void)
348: {
349: static char *gen = "2", *group1 =
350: "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
351: "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
352: "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
353: "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
354: "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
355: "FFFFFFFF" "FFFFFFFF";
356:
357: return (dh_new_group_asc(gen, group1));
1.30 djm 358: }
359:
1.60 djm 360: /* rfc3526 group 14 "2048-bit MODP Group" */
1.30 djm 361: DH *
362: dh_new_group14(void)
363: {
364: static char *gen = "2", *group14 =
365: "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
366: "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
367: "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
368: "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
369: "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D"
370: "C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F"
371: "83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D"
372: "670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B"
373: "E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9"
374: "DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510"
375: "15728E5A" "8AACAA68" "FFFFFFFF" "FFFFFFFF";
376:
377: return (dh_new_group_asc(gen, group14));
1.57 dtucker 378: }
379:
1.60 djm 380: /* rfc3526 group 16 "4096-bit MODP Group" */
1.57 dtucker 381: DH *
1.60 djm 382: dh_new_group16(void)
1.57 dtucker 383: {
384: static char *gen = "2", *group16 =
385: "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
386: "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
387: "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
388: "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
389: "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D"
390: "C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F"
391: "83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D"
392: "670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B"
393: "E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9"
394: "DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510"
395: "15728E5A" "8AAAC42D" "AD33170D" "04507A33" "A85521AB" "DF1CBA64"
396: "ECFB8504" "58DBEF0A" "8AEA7157" "5D060C7D" "B3970F85" "A6E1E4C7"
397: "ABF5AE8C" "DB0933D7" "1E8C94E0" "4A25619D" "CEE3D226" "1AD2EE6B"
398: "F12FFA06" "D98A0864" "D8760273" "3EC86A64" "521F2B18" "177B200C"
399: "BBE11757" "7A615D6C" "770988C0" "BAD946E2" "08E24FA0" "74E5AB31"
400: "43DB5BFC" "E0FD108E" "4B82D120" "A9210801" "1A723C12" "A787E6D7"
401: "88719A10" "BDBA5B26" "99C32718" "6AF4E23C" "1A946834" "B6150BDA"
402: "2583E9CA" "2AD44CE8" "DBBBC2DB" "04DE8EF9" "2E8EFC14" "1FBECAA6"
403: "287C5947" "4E6BC05D" "99B2964F" "A090C3A2" "233BA186" "515BE7ED"
404: "1F612970" "CEE2D7AF" "B81BDD76" "2170481C" "D0069127" "D5B05AA9"
405: "93B4EA98" "8D8FDDC1" "86FFB7DC" "90A6C08F" "4DF435C9" "34063199"
406: "FFFFFFFF" "FFFFFFFF";
407:
1.60 djm 408: return (dh_new_group_asc(gen, group16));
409: }
410:
411: /* rfc3526 group 18 "8192-bit MODP Group" */
412: DH *
413: dh_new_group18(void)
414: {
1.69 djm 415: static char *gen = "2", *group18 =
1.60 djm 416: "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
417: "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
418: "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
419: "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
420: "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D"
421: "C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F"
422: "83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D"
423: "670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B"
424: "E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9"
425: "DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510"
426: "15728E5A" "8AAAC42D" "AD33170D" "04507A33" "A85521AB" "DF1CBA64"
427: "ECFB8504" "58DBEF0A" "8AEA7157" "5D060C7D" "B3970F85" "A6E1E4C7"
428: "ABF5AE8C" "DB0933D7" "1E8C94E0" "4A25619D" "CEE3D226" "1AD2EE6B"
429: "F12FFA06" "D98A0864" "D8760273" "3EC86A64" "521F2B18" "177B200C"
430: "BBE11757" "7A615D6C" "770988C0" "BAD946E2" "08E24FA0" "74E5AB31"
431: "43DB5BFC" "E0FD108E" "4B82D120" "A9210801" "1A723C12" "A787E6D7"
432: "88719A10" "BDBA5B26" "99C32718" "6AF4E23C" "1A946834" "B6150BDA"
433: "2583E9CA" "2AD44CE8" "DBBBC2DB" "04DE8EF9" "2E8EFC14" "1FBECAA6"
434: "287C5947" "4E6BC05D" "99B2964F" "A090C3A2" "233BA186" "515BE7ED"
435: "1F612970" "CEE2D7AF" "B81BDD76" "2170481C" "D0069127" "D5B05AA9"
436: "93B4EA98" "8D8FDDC1" "86FFB7DC" "90A6C08F" "4DF435C9" "34028492"
437: "36C3FAB4" "D27C7026" "C1D4DCB2" "602646DE" "C9751E76" "3DBA37BD"
438: "F8FF9406" "AD9E530E" "E5DB382F" "413001AE" "B06A53ED" "9027D831"
439: "179727B0" "865A8918" "DA3EDBEB" "CF9B14ED" "44CE6CBA" "CED4BB1B"
440: "DB7F1447" "E6CC254B" "33205151" "2BD7AF42" "6FB8F401" "378CD2BF"
441: "5983CA01" "C64B92EC" "F032EA15" "D1721D03" "F482D7CE" "6E74FEF6"
442: "D55E702F" "46980C82" "B5A84031" "900B1C9E" "59E7C97F" "BEC7E8F3"
443: "23A97A7E" "36CC88BE" "0F1D45B7" "FF585AC5" "4BD407B2" "2B4154AA"
444: "CC8F6D7E" "BF48E1D8" "14CC5ED2" "0F8037E0" "A79715EE" "F29BE328"
445: "06A1D58B" "B7C5DA76" "F550AA3D" "8A1FBFF0" "EB19CCB1" "A313D55C"
446: "DA56C9EC" "2EF29632" "387FE8D7" "6E3C0468" "043E8F66" "3F4860EE"
447: "12BF2D5B" "0B7474D6" "E694F91E" "6DBE1159" "74A3926F" "12FEE5E4"
448: "38777CB6" "A932DF8C" "D8BEC4D0" "73B931BA" "3BC832B6" "8D9DD300"
449: "741FA7BF" "8AFC47ED" "2576F693" "6BA42466" "3AAB639C" "5AE4F568"
450: "3423B474" "2BF1C978" "238F16CB" "E39D652D" "E3FDB8BE" "FC848AD9"
451: "22222E04" "A4037C07" "13EB57A8" "1A23F0C7" "3473FC64" "6CEA306B"
452: "4BCBC886" "2F8385DD" "FA9D4B7F" "A2C087E8" "79683303" "ED5BDD3A"
453: "062B3CF5" "B3A278A6" "6D2A13F8" "3F44F82D" "DF310EE0" "74AB6A36"
454: "4597E899" "A0255DC1" "64F31CC5" "0846851D" "F9AB4819" "5DED7EA1"
455: "B1D510BD" "7EE74D73" "FAF36BC3" "1ECFA268" "359046F4" "EB879F92"
456: "4009438B" "481C6CD7" "889A002E" "D5EE382B" "C9190DA6" "FC026E47"
457: "9558E447" "5677E9AA" "9E3050E2" "765694DF" "C81F56E8" "80B96E71"
458: "60C980DD" "98EDD3DF" "FFFFFFFF" "FFFFFFFF";
459:
1.69 djm 460: return (dh_new_group_asc(gen, group18));
1.60 djm 461: }
462:
463: /* Select fallback group used by DH-GEX if moduli file cannot be read. */
464: DH *
465: dh_new_group_fallback(int max)
466: {
1.72 djm 467: debug3_f("requested max size %d", max);
1.60 djm 468: if (max < 3072) {
469: debug3("using 2k bit group 14");
1.57 dtucker 470: return dh_new_group14();
1.60 djm 471: } else if (max < 6144) {
472: debug3("using 4k bit group 16");
473: return dh_new_group16();
1.57 dtucker 474: }
1.60 djm 475: debug3("using 8k bit group 18");
476: return dh_new_group18();
1.12 markus 477: }
478:
479: /*
480: * Estimates the group order for a Diffie-Hellman group that has an
1.52 dtucker 481: * attack complexity approximately the same as O(2**bits).
482: * Values from NIST Special Publication 800-57: Recommendation for Key
483: * Management Part 1 (rev 3) limited by the recommended maximum value
484: * from RFC4419 section 3.
1.12 markus 485: */
1.54 markus 486: u_int
1.12 markus 487: dh_estimate(int bits)
488: {
1.52 dtucker 489: if (bits <= 112)
490: return 2048;
1.26 markus 491: if (bits <= 128)
1.52 dtucker 492: return 3072;
1.26 markus 493: if (bits <= 192)
1.52 dtucker 494: return 7680;
495: return 8192;
1.1 provos 496: }