src/usr.bin/ssh/dh.c - diff

Return to dh.c CVS log

Up to [local] / src / usr.bin / ssh

Diff for /src/usr.bin/ssh/dh.c between version 1.10 and 1.11

-version 1.10, 2001/03/28 22:04:57
+version 1.11, 2001/03/29 21:17:39
 Line 166
 Line 166
 Line 166
          return (dh_new_group(dhg.g, dhg.p));
  }
+ /* diffie-hellman-group1-sha1 */
+ int
+ dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
+ {
+         int i;
+         int n = BN_num_bits(dh_pub);
+         int bits_set = 0;
+         if (dh_pub->neg) {
+                 log("invalid public DH value: negativ");
+                 return 0;
+         }
+         for (i = 0; i <= n; i++)
+                 if (BN_is_bit_set(dh_pub, i))
+                         bits_set++;
+         debug("bits set: %d/%d", bits_set, BN_num_bits(dh->p));
+         /* 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));
+         return 0;
+ }
+ void
+ dh_gen_key(DH *dh, int need)
+ {
+         int i, bits_set = 0, tries = 0;
+         if (dh->p == NULL)
+                 fatal("dh_gen_key: dh->p == NULL");
+         if (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 {
+                 if (dh->priv_key != NULL)
+                         BN_free(dh->priv_key);
+                 dh->priv_key = BN_new();
+                 if (dh->priv_key == NULL)
+                         fatal("dh_gen_key: BN_new failed");
+                 /* generate a 2*need bits random private exponent */
+                 if (!BN_rand(dh->priv_key, 2*need, 0, 0))
+                         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++)
+                         if (BN_is_bit_set(dh->priv_key, i))
+                                 bits_set++;
+                 debug("dh_gen_key: priv key bits set: %d/%d",
+                     bits_set, BN_num_bits(dh->priv_key));
+                 if (tries++ > 10)
+                         fatal("dh_gen_key: too many bad keys: giving up");
+         } while (!dh_pub_is_valid(dh, dh->pub_key));
+ }
+ DH *
+ dh_new_group_asc(const char *gen, const char *modulus)
+ {
+         DH *dh;
+         int ret;
+         dh = DH_new();
+         if (dh == NULL)
+                 fatal("DH_new");
+         if ((ret = BN_hex2bn(&dh->p, modulus)) < 0)
+                 fatal("BN_hex2bn p");
+         if ((ret = BN_hex2bn(&dh->g, gen)) < 0)
+                 fatal("BN_hex2bn g");
+         return (dh);
+ }
+ /*
+  * This just returns the group, we still need to generate the exchange
+  * value.
+  */
+ DH *
+ dh_new_group(BIGNUM *gen, BIGNUM *modulus)
+ {
+         DH *dh;
+         dh = DH_new();
+         if (dh == NULL)
+                 fatal("DH_new");
+         dh->p = modulus;
+         dh->g = gen;
+         return (dh);
+ }
+ DH *
+ dh_new_group1(void)
+ {
+         static char *gen = "2", *group1 =
+             "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" "ECE65381"
+             "FFFFFFFF" "FFFFFFFF";
+         return (dh_new_group_asc(gen, group1));
+ }