X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/35efb24c5aeaf14bc6e2dac993d6e6f1778cd9bb..e45da4d6928b5f35b9add90897665eaec43ac108:/dh.c diff --git a/dh.c b/dh.c index 1be51953..044d869f 100644 --- a/dh.c +++ b/dh.c @@ -23,7 +23,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: dh.c,v 1.23 2002/11/21 22:22:50 markus Exp $"); +RCSID("$OpenBSD: dh.c,v 1.31 2004/08/04 10:37:52 djm Exp $"); #include "xmalloc.h" @@ -91,6 +91,9 @@ parse_prime(int linenum, char *line, struct dhgroup *dhg) if (BN_num_bits(dhg->p) != dhg->size) goto failclean; + if (BN_is_zero(dhg->g) || BN_is_one(dhg->g)) + goto failclean; + return (1); failclean: @@ -105,15 +108,16 @@ DH * choose_dh(int min, int wantbits, int max) { FILE *f; - char line[2048]; + char line[4096]; int best, bestcount, which; int linenum; struct dhgroup dhg; if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL && (f = fopen(_PATH_DH_PRIMES, "r")) == NULL) { - log("WARNING: %s does not exist, using old modulus", _PATH_DH_MODULI); - return (dh_new_group1()); + logit("WARNING: %s does not exist, using fixed modulus", + _PATH_DH_MODULI); + return (dh_new_group14()); } linenum = 0; @@ -140,8 +144,8 @@ choose_dh(int min, int wantbits, int max) if (bestcount == 0) { fclose(f); - log("WARNING: no suitable primes in %s", _PATH_DH_PRIMES); - return (NULL); + logit("WARNING: no suitable primes in %s", _PATH_DH_PRIMES); + return (dh_new_group14()); } linenum = 0; @@ -166,7 +170,7 @@ choose_dh(int min, int wantbits, int max) return (dh_new_group(dhg.g, dhg.p)); } -/* diffie-hellman-group1-sha1 */ +/* diffie-hellman-groupN-sha1 */ int dh_pub_is_valid(DH *dh, BIGNUM *dh_pub) @@ -176,7 +180,7 @@ dh_pub_is_valid(DH *dh, BIGNUM *dh_pub) int bits_set = 0; if (dh_pub->neg) { - log("invalid public DH value: negativ"); + logit("invalid public DH value: negativ"); return 0; } for (i = 0; i <= n; i++) @@ -187,18 +191,18 @@ dh_pub_is_valid(DH *dh, BIGNUM *dh_pub) /* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */ if (bits_set > 1 && (BN_cmp(dh_pub, dh->p) == -1)) return 1; - log("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p)); + logit("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p)); return 0; } void dh_gen_key(DH *dh, int need) { - int i, bits_set = 0, tries = 0; + int i, bits_set, tries = 0; if (dh->p == NULL) fatal("dh_gen_key: dh->p == NULL"); - if (2*need >= BN_num_bits(dh->p)) + if (need > INT_MAX / 2 || 2 * need >= BN_num_bits(dh->p)) fatal("dh_gen_key: group too small: %d (2*need %d)", BN_num_bits(dh->p), 2*need); do { @@ -211,7 +215,7 @@ dh_gen_key(DH *dh, int need) fatal("dh_gen_key: BN_rand failed"); if (DH_generate_key(dh) == 0) fatal("DH_generate_key"); - for (i = 0; i <= BN_num_bits(dh->priv_key); i++) + for (i = 0, bits_set = 0; i <= BN_num_bits(dh->priv_key); i++) if (BN_is_bit_set(dh->priv_key, i)) bits_set++; debug2("dh_gen_key: priv key bits set: %d/%d", @@ -269,6 +273,25 @@ dh_new_group1(void) return (dh_new_group_asc(gen, group1)); } +DH * +dh_new_group14(void) +{ + static char *gen = "2", *group14 = + "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1" + "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD" + "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245" + "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED" + "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D" + "C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F" + "83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D" + "670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B" + "E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9" + "DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510" + "15728E5A" "8AACAA68" "FFFFFFFF" "FFFFFFFF"; + + return (dh_new_group_asc(gen, group14)); +} + /* * Estimates the group order for a Diffie-Hellman group that has an * attack complexity approximately the same as O(2**bits). Estimate @@ -279,11 +302,9 @@ int dh_estimate(int bits) { - if (bits < 64) - return (512); /* O(2**63) */ - if (bits < 128) + if (bits <= 128) return (1024); /* O(2**86) */ - if (bits < 192) + if (bits <= 192) return (2048); /* O(2**116) */ return (4096); /* O(2**156) */ }