- djm@cvs.openbsd.org 2009/03/05 07:18:19

     [auth2-jpake.c jpake.c jpake.h monitor_wrap.c monitor_wrap.h schnorr.c]
     [sshconnect2.c]
     refactor the (disabled) Schnorr proof code to make it a little more
     generally useful

1 files changed, 13 insertions, 168 deletions

diff --git a/jpake.c b/jpake.c
index 565f2e255..130661069 100644
--- a/jpake.c
+++ b/jpake.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: jpake.c,v 1.1 2008/11/04 08:22:12 djm Exp $ */
+/* $OpenBSD: jpake.c,v 1.2 2009/03/05 07:18:19 djm Exp $ */
 /*
  * Copyright (c) 2008 Damien Miller.  All rights reserved.
  *
@@ -47,6 +47,7 @@
 #include "log.h"
 
 #include "jpake.h"
+#include "schnorr.h"
 
 #ifdef JPAKE
 
@@ -60,165 +61,10 @@
         "98DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB" \
         "9ED529077096966D670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF"
 
-struct jpake_group *
+struct modp_group *
 jpake_default_group(void)
 {
-        struct jpake_group *ret;
-
-        ret = xmalloc(sizeof(*ret));
-        ret->p = ret->q = ret->g = NULL;
-        if (BN_hex2bn(&ret->p, JPAKE_GROUP_P) == 0 ||
-            BN_hex2bn(&ret->g, JPAKE_GROUP_G) == 0)
-                fatal("%s: BN_hex2bn", __func__);
-        /* Subgroup order is p/2 (p is a safe prime) */
-        if ((ret->q = BN_new()) == NULL)
-                fatal("%s: BN_new", __func__);
-        if (BN_rshift1(ret->q, ret->p) != 1)
-                fatal("%s: BN_rshift1", __func__);
-
-        return ret;
-}
-
-/*
- * Generate uniformly distributed random number in range (1, high).
- * Return number on success, NULL on failure.
- */
-BIGNUM *
-bn_rand_range_gt_one(const BIGNUM *high)
-{
-        BIGNUM *r, *tmp;
-        int success = -1;
-
-        if ((tmp = BN_new()) == NULL) {
-                error("%s: BN_new", __func__);
-                return NULL;
-        }
-        if ((r = BN_new()) == NULL) {
-                error("%s: BN_new failed", __func__);
-                goto out;
-        }
-        if (BN_set_word(tmp, 2) != 1) {
-                error("%s: BN_set_word(tmp, 2)", __func__);
-                goto out;
-        }
-        if (BN_sub(tmp, high, tmp) == -1) {
-                error("%s: BN_sub failed (tmp = high - 2)", __func__);
-                goto out;
-        }
-        if (BN_rand_range(r, tmp) == -1) {
-                error("%s: BN_rand_range failed", __func__);
-                goto out;
-        }
-        if (BN_set_word(tmp, 2) != 1) {
-                error("%s: BN_set_word(tmp, 2)", __func__);
-                goto out;
-        }
-        if (BN_add(r, r, tmp) == -1) {
-                error("%s: BN_add failed (r = r + 2)", __func__);
-                goto out;
-        }
-        success = 0;
- out:
-        BN_clear_free(tmp);
-        if (success == 0)
-                return r;
-        BN_clear_free(r);
-        return NULL;
-}
-
-/*
- * Hash contents of buffer 'b' with hash 'md'. Returns 0 on success,
- * with digest via 'digestp' (caller to free) and length via 'lenp'.
- * Returns -1 on failure.
- */
-int
-hash_buffer(const u_char *buf, u_int len, const EVP_MD *md,
-    u_char **digestp, u_int *lenp)
-{
-        u_char digest[EVP_MAX_MD_SIZE];
-        u_int digest_len;
-        EVP_MD_CTX evp_md_ctx;
-        int success = -1;
-
-        EVP_MD_CTX_init(&evp_md_ctx);
-
-        if (EVP_DigestInit_ex(&evp_md_ctx, md, NULL) != 1) {
-                error("%s: EVP_DigestInit_ex", __func__);
-                goto out;
-        }
-        if (EVP_DigestUpdate(&evp_md_ctx, buf, len) != 1) {
-                error("%s: EVP_DigestUpdate", __func__);
-                goto out;
-        }
-        if (EVP_DigestFinal_ex(&evp_md_ctx, digest, &digest_len) != 1) {
-                error("%s: EVP_DigestFinal_ex", __func__);
-                goto out;
-        }
-        *digestp = xmalloc(digest_len);
-        *lenp = digest_len;
-        memcpy(*digestp, digest, *lenp);
-        success = 0;
- out:
-        EVP_MD_CTX_cleanup(&evp_md_ctx);
-        bzero(digest, sizeof(digest));
-        digest_len = 0;
-        return success;
-}
-
-/* print formatted string followed by bignum */
-void
-jpake_debug3_bn(const BIGNUM *n, const char *fmt, ...)
-{
-        char *out, *h;
-        va_list args;
-
-        out = NULL;
-        va_start(args, fmt);
-        vasprintf(&out, fmt, args);
-        va_end(args);
-        if (out == NULL)
-                fatal("%s: vasprintf failed", __func__);
-
-        if (n == NULL)
-                debug3("%s(null)", out);
-        else {
-                h = BN_bn2hex(n);
-                debug3("%s0x%s", out, h);
-                free(h);
-        }
-        free(out);
-}
-
-/* print formatted string followed by buffer contents in hex */
-void
-jpake_debug3_buf(const u_char *buf, u_int len, const char *fmt, ...)
-{
-        char *out, h[65];
-        u_int i, j;
-        va_list args;
-
-        out = NULL;
-        va_start(args, fmt);
-        vasprintf(&out, fmt, args);
-        va_end(args);
-        if (out == NULL)
-                fatal("%s: vasprintf failed", __func__);
-
-        debug3("%s length %u%s", out, len, buf == NULL ? " (null)" : "");
-        free(out);
-        if (buf == NULL)
-                return;
-
-        *h = '\0';
-        for (i = j = 0; i < len; i++) {
-                snprintf(h + j, sizeof(h) - j, "%02x", buf[i]);
-                j += 2;
-                if (j >= sizeof(h) - 1 || i == len - 1) {
-                        debug3("    %s", h);
-                        *h = '\0';
-                        j = 0;
-                }
-        }
+        return modp_group_from_g_and_safe_p(JPAKE_GROUP_G, JPAKE_GROUP_P);
 }
 
 struct jpake_ctx *
@@ -243,7 +89,6 @@ jpake_new(void)
         return ret;
 }
 
-
 void
 jpake_free(struct jpake_ctx *pctx)
 {
@@ -344,7 +189,7 @@ jpake_dump(struct jpake_ctx *pctx, const char *fmt, ...)
 
 /* Shared parts of step 1 exchange calculation */
 void
-jpake_step1(struct jpake_group *grp,
+jpake_step1(struct modp_group *grp,
     u_char **id, u_int *id_len,
     BIGNUM **priv1, BIGNUM **priv2, BIGNUM **g_priv1, BIGNUM **g_priv2,
     u_char **priv1_proof, u_int *priv1_proof_len,
@@ -383,11 +228,11 @@ jpake_step1(struct jpake_group *grp,
                 fatal("%s: BN_mod_exp", __func__);
 
         /* Generate proofs for holding x1/x3 and x2/x4 */
-        if (schnorr_sign(grp->p, grp->q, grp->g,
+        if (schnorr_sign_buf(grp->p, grp->q, grp->g,
             *priv1, *g_priv1, *id, *id_len,
             priv1_proof, priv1_proof_len) != 0)
                 fatal("%s: schnorr_sign", __func__);
-        if (schnorr_sign(grp->p, grp->q, grp->g,
+        if (schnorr_sign_buf(grp->p, grp->q, grp->g,
             *priv2, *g_priv2, *id, *id_len,
             priv2_proof, priv2_proof_len) != 0)
                 fatal("%s: schnorr_sign", __func__);
@@ -397,7 +242,7 @@ jpake_step1(struct jpake_group *grp,
 
 /* Shared parts of step 2 exchange calculation */
 void
-jpake_step2(struct jpake_group *grp, BIGNUM *s,
+jpake_step2(struct modp_group *grp, BIGNUM *s,
     BIGNUM *mypub1, BIGNUM *theirpub1, BIGNUM *theirpub2, BIGNUM *mypriv2,
     const u_char *theirid, u_int theirid_len,
     const u_char *myid, u_int myid_len,
@@ -415,10 +260,10 @@ jpake_step2(struct jpake_group *grp, BIGNUM *s,
         if (BN_cmp(theirpub2, BN_value_one()) <= 0)
                 fatal("%s: theirpub2 <= 1", __func__);
 
-        if (schnorr_verify(grp->p, grp->q, grp->g, theirpub1,
+        if (schnorr_verify_buf(grp->p, grp->q, grp->g, theirpub1,
             theirid, theirid_len, theirpub1_proof, theirpub1_proof_len) != 1)
                 fatal("%s: schnorr_verify theirpub1 failed", __func__);
-        if (schnorr_verify(grp->p, grp->q, grp->g, theirpub2,
+        if (schnorr_verify_buf(grp->p, grp->q, grp->g, theirpub2,
             theirid, theirid_len, theirpub2_proof, theirpub2_proof_len) != 1)
                 fatal("%s: schnorr_verify theirpub2 failed", __func__);
 
@@ -459,7 +304,7 @@ jpake_step2(struct jpake_group *grp, BIGNUM *s,
         JPAKE_DEBUG_BN((exponent, "%s: exponent = ", __func__));
 
         /* Note the generator here is 'tmp', not g */
-        if (schnorr_sign(grp->p, grp->q, tmp, exponent, *newpub,
+        if (schnorr_sign_buf(grp->p, grp->q, tmp, exponent, *newpub,
             myid, myid_len,
             newpub_exponent_proof, newpub_exponent_proof_len) != 0)
                 fatal("%s: schnorr_sign newpub", __func__);
@@ -496,7 +341,7 @@ jpake_confirm_hash(const BIGNUM *k,
 
 /* Shared parts of key derivation and confirmation calculation */
 void
-jpake_key_confirm(struct jpake_group *grp, BIGNUM *s, BIGNUM *step2_val,
+jpake_key_confirm(struct modp_group *grp, BIGNUM *s, BIGNUM *step2_val,
     BIGNUM *mypriv2, BIGNUM *mypub1, BIGNUM *mypub2,
     BIGNUM *theirpub1, BIGNUM *theirpub2,
     const u_char *my_id, u_int my_id_len,
@@ -531,7 +376,7 @@ jpake_key_confirm(struct jpake_group *grp, BIGNUM *s, BIGNUM *step2_val,
 
         JPAKE_DEBUG_BN((tmp, "%s: tmp = ", __func__));
 
-        if (schnorr_verify(grp->p, grp->q, tmp, step2_val, 
+        if (schnorr_verify_buf(grp->p, grp->q, tmp, step2_val, 
             their_id, their_id_len,
             theirpriv2_s_proof, theirpriv2_s_proof_len) != 1)
                 fatal("%s: schnorr_verify theirpriv2_s_proof failed", __func__);