packetstorm sync

1 files changed, 294 insertions, 0 deletions

diff --git a/other/ssharp/dh.c b/other/ssharp/dh.c
new file mode 100644
index 0000000..575522d
--- /dev/null
+++ b/other/ssharp/dh.c
@@ -0,0 +1,294 @@
+/*
+ * Copyright (c) 2000 Niels Provos.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: dh.c,v 1.14 2001/04/15 08:43:45 markus Exp $");
+
+#include "xmalloc.h"
+
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+#include <openssl/evp.h>
+
+#include "buffer.h"
+#include "cipher.h"
+#include "kex.h"
+#include "dh.h"
+#include "pathnames.h"
+#include "log.h"
+#include "misc.h"
+
+int
+parse_prime(int linenum, char *line, struct dhgroup *dhg)
+{
+        char *cp, *arg;
+        char *strsize, *gen, *prime;
+
+        cp = line;
+        arg = strdelim(&cp);
+        /* Ignore leading whitespace */
+        if (*arg == '\0')
+                arg = strdelim(&cp);
+        if (!*arg || *arg == '#')
+                return 0;
+
+        /* time */
+        if (cp == NULL || *arg == '\0')
+                goto fail;
+        arg = strsep(&cp, " "); /* type */
+        if (cp == NULL || *arg == '\0')
+                goto fail;
+        arg = strsep(&cp, " "); /* tests */
+        if (cp == NULL || *arg == '\0')
+                goto fail;
+        arg = strsep(&cp, " "); /* tries */
+        if (cp == NULL || *arg == '\0')
+                goto fail;
+        strsize = strsep(&cp, " "); /* size */
+        if (cp == NULL || *strsize == '\0' ||
+            (dhg->size = atoi(strsize)) == 0)
+                goto fail;
+        /* The whole group is one bit larger */
+        dhg->size++;
+        gen = strsep(&cp, " "); /* gen */
+        if (cp == NULL || *gen == '\0')
+                goto fail;
+        prime = strsep(&cp, " "); /* prime */
+        if (cp != NULL || *prime == '\0')
+                goto fail;
+
+        dhg->g = BN_new();
+        dhg->p = BN_new();
+        if (BN_hex2bn(&dhg->g, gen) == 0)
+                goto failclean;
+
+        if (BN_hex2bn(&dhg->p, prime) == 0)
+                goto failclean;
+
+        if (BN_num_bits(dhg->p) != dhg->size)
+                goto failclean;
+
+        return (1);
+
+ failclean:
+        BN_free(dhg->g);
+        BN_free(dhg->p);
+ fail:
+        error("Bad prime description in line %d", linenum);
+        return (0);
+}
+
+DH *
+choose_dh(int min, int wantbits, int max)
+{
+        FILE *f;
+        char line[1024];
+        int best, bestcount, which;
+        int linenum;
+        struct dhgroup dhg;
+
+        f = fopen(_PATH_DH_PRIMES, "r");
+        if (!f) {
+                log("WARNING: %s does not exist, using old prime", _PATH_DH_PRIMES);
+                return (dh_new_group1());
+        }
+
+        linenum = 0;
+        best = bestcount = 0;
+        while (fgets(line, sizeof(line), f)) {
+                linenum++;
+                if (!parse_prime(linenum, line, &dhg))
+                        continue;
+                BN_free(dhg.g);
+                BN_free(dhg.p);
+
+                if (dhg.size > max || dhg.size < min)
+                        continue;
+
+                if ((dhg.size > wantbits && dhg.size < best) ||
+                    (dhg.size > best && best < wantbits)) {
+                        best = dhg.size;
+                        bestcount = 0;
+                }
+                if (dhg.size == best)
+                        bestcount++;
+        }
+        fclose (f);
+
+        if (bestcount == 0) {
+                log("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
+                return (NULL);
+        }
+
+        f = fopen(_PATH_DH_PRIMES, "r");
+        if (!f) {
+                fatal("WARNING: %s disappeared, giving up", _PATH_DH_PRIMES);
+        }
+
+        linenum = 0;
+        which = arc4random() % bestcount;
+        while (fgets(line, sizeof(line), f)) {
+                if (!parse_prime(linenum, line, &dhg))
+                        continue;
+                if ((dhg.size > max || dhg.size < min) ||
+                    dhg.size != best ||
+                    linenum++ != which) {
+                        BN_free(dhg.g);
+                        BN_free(dhg.p);
+                        continue;
+                }
+                break;
+        }
+        fclose(f);
+        if (linenum != which+1)
+                fatal("WARNING: line %d disappeared in %s, giving up",
+                    which, _PATH_DH_PRIMES);
+
+        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;
+
+        dh = DH_new();
+        if (dh == NULL)
+                fatal("DH_new");
+
+        if (BN_hex2bn(&dh->p, modulus) == 0)
+                fatal("BN_hex2bn p");
+        if (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));
+}
+
+/*
+ * Estimates the group order for a Diffie-Hellman group that has an
+ * attack complexity approximately the same as O(2**bits).  Estimate
+ * with:  O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
+ */
+
+int
+dh_estimate(int bits)
+{
+
+        if (bits < 64)
+                return (512);   /* O(2**63) */
+        if (bits < 128)
+                return (1024);  /* O(2**86) */
+        if (bits < 192)
+                return (2048);  /* O(2**116) */
+        return (4096);          /* O(2**156) */
+}