add GssapiCredentialsPath option for sshd_config as requested in

[gssapi-openssh.git] / openssh / kex.c

diff --git a/openssh/kex.c b/openssh/kex.c
index 8cd851d232af2873578b85334528f293fa8c711c..ac74079fcdd0060f45996ca022950ef54a72d188 100644 (file)
--- a/openssh/kex.c
+++ b/openssh/kex.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: kex.c,v 1.76 2006/08/03 03:34:42 deraadt Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
@@ -23,19 +24,25 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: kex.c,v 1.64 2005/07/25 11:59:39 markus Exp $");
+
+#include <sys/param.h>
+
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include <openssl/crypto.h>
 
-#include "ssh2.h"
 #include "xmalloc.h"
+#include "ssh2.h"
 #include "buffer.h"
-#include "bufaux.h"
 #include "packet.h"
 #include "compat.h"
 #include "cipher.h"
-#include "kex.h"
 #include "key.h"
+#include "kex.h"
 #include "log.h"
 #include "mac.h"
 #include "match.h"
@@ -48,12 +55,20 @@ RCSID("$OpenBSD: kex.c,v 1.64 2005/07/25 11:59:39 markus Exp $");
 
 #define KEX_COOKIE_LEN 16
 
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L
+# if defined(HAVE_EVP_SHA256)
+# define evp_ssh_sha256 EVP_sha256
+# else
+extern const EVP_MD *evp_ssh_sha256(void);
+# endif
+#endif
+
 /* prototype */
 static void kex_kexinit_finish(Kex *);
 static void kex_choose_conf(Kex *);
 
 /* put algorithm proposal into buffer */
-static void
+void
 kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
 {
        u_int i;
@@ -79,7 +94,7 @@ kex_buf2prop(Buffer *raw, int *first_kex_follows)
        int i;
        char **proposal;
 
-       proposal = xmalloc(PROPOSAL_MAX * sizeof(char *));
+       proposal = xcalloc(PROPOSAL_MAX, sizeof(char *));
 
        buffer_init(&b);
        buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
@@ -214,8 +229,7 @@ kex_setup(char *proposal[PROPOSAL_MAX])
 {
        Kex *kex;
 
-       kex = xmalloc(sizeof(*kex));
-       memset(kex, 0, sizeof(*kex));
+       kex = xcalloc(1, sizeof(*kex));
        buffer_init(&kex->peer);
        buffer_init(&kex->my);
        kex_prop2buf(&kex->my, proposal);
@@ -258,6 +272,7 @@ choose_enc(Enc *enc, char *client, char *server)
        enc->key_len = cipher_keylen(enc->cipher);
        enc->block_size = cipher_blocksize(enc->cipher);
 }
+
 static void
 choose_mac(Mac *mac, char *client, char *server)
 {
@@ -273,6 +288,7 @@ choose_mac(Mac *mac, char *client, char *server)
        mac->key = NULL;
        mac->enabled = 0;
 }
+
 static void
 choose_comp(Comp *comp, char *client, char *server)
 {
@@ -290,6 +306,7 @@ choose_comp(Comp *comp, char *client, char *server)
        }
        comp->name = name;
 }
+
 static void
 choose_kex(Kex *k, char *client, char *server)
 {
@@ -298,21 +315,36 @@ choose_kex(Kex *k, char *client, char *server)
                fatal("no kex alg");
        if (strcmp(k->name, KEX_DH1) == 0) {
                k->kex_type = KEX_DH_GRP1_SHA1;
+               k->evp_md = EVP_sha1();
        } else if (strcmp(k->name, KEX_DH14) == 0) {
                k->kex_type = KEX_DH_GRP14_SHA1;
-       } else if (strcmp(k->name, KEX_DHGEX) == 0) {
+               k->evp_md = EVP_sha1();
+       } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
                k->kex_type = KEX_DH_GEX_SHA1;
+               k->evp_md = EVP_sha1();
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L
+       } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) {
+               k->kex_type = KEX_DH_GEX_SHA256;
+               k->evp_md = evp_ssh_sha256();
+#endif
 #ifdef GSSAPI
        } else if (strncmp(k->name, KEX_GSS_GEX_SHA1_ID,
-           sizeof(KEX_GSS_GEX_SHA1_ID)-1) == 0) {
+           sizeof(KEX_GSS_GEX_SHA1_ID) - 1) == 0) {
                k->kex_type = KEX_GSS_GEX_SHA1;
-       } else if (strncmp(k->name, KEX_GSS_GRP1_SHA1_ID, 
-           sizeof(KEX_GSS_GRP1_SHA1_ID)-1) == 0) {
+               k->evp_md = EVP_sha1();
+       } else if (strncmp(k->name, KEX_GSS_GRP1_SHA1_ID,
+           sizeof(KEX_GSS_GRP1_SHA1_ID) - 1) == 0) {
                k->kex_type = KEX_GSS_GRP1_SHA1;
+               k->evp_md = EVP_sha1();
+       } else if (strncmp(k->name, KEX_GSS_GRP14_SHA1_ID,
+           sizeof(KEX_GSS_GRP14_SHA1_ID) - 1) == 0) {
+               k->kex_type = KEX_GSS_GRP14_SHA1;
+               k->evp_md = EVP_sha1();
 #endif
        } else
                fatal("bad kex alg %s", k->name);
 }
+
 static void
 choose_hostkeyalg(Kex *k, char *client, char *server)
 {
@@ -372,8 +404,7 @@ kex_choose_conf(Kex *kex)
 
        /* Algorithm Negotiation */
        for (mode = 0; mode < MODE_MAX; mode++) {
-               newkeys = xmalloc(sizeof(*newkeys));
-               memset(newkeys, 0, sizeof(*newkeys));
+               newkeys = xcalloc(1, sizeof(*newkeys));
                kex->newkeys[mode] = newkeys;
                ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
                nenc  = ctos ? PROPOSAL_ENC_ALGS_CTOS  : PROPOSAL_ENC_ALGS_STOC;
@@ -416,28 +447,28 @@ kex_choose_conf(Kex *kex)
 }
 
 static u_char *
-derive_key(Kex *kex, int id, u_int need, u_char *hash, BIGNUM *shared_secret)
+derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
+    BIGNUM *shared_secret)
 {
        Buffer b;
-       const EVP_MD *evp_md = EVP_sha1();
        EVP_MD_CTX md;
        char c = id;
        u_int have;
-       int mdsz = EVP_MD_size(evp_md);
+       int mdsz;
        u_char *digest;
 
-       if (mdsz < 0)
-               fatal("derive_key: mdsz < 0");
+       if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
+               fatal("bad kex md size %d", mdsz);
        digest = xmalloc(roundup(need, mdsz));
 
        buffer_init(&b);
        buffer_put_bignum2(&b, shared_secret);
 
        /* K1 = HASH(K || H || "A" || session_id) */
-       EVP_DigestInit(&md, evp_md);
+       EVP_DigestInit(&md, kex->evp_md);
        if (!(datafellows & SSH_BUG_DERIVEKEY))
                EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
-       EVP_DigestUpdate(&md, hash, mdsz);
+       EVP_DigestUpdate(&md, hash, hashlen);
        EVP_DigestUpdate(&md, &c, 1);
        EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
        EVP_DigestFinal(&md, digest, NULL);
@@ -448,10 +479,10 @@ derive_key(Kex *kex, int id, u_int need, u_char *hash, BIGNUM *shared_secret)
         * Key = K1 || K2 || ... || Kn
         */
        for (have = mdsz; need > have; have += mdsz) {
-               EVP_DigestInit(&md, evp_md);
+               EVP_DigestInit(&md, kex->evp_md);
                if (!(datafellows & SSH_BUG_DERIVEKEY))
                        EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
-               EVP_DigestUpdate(&md, hash, mdsz);
+               EVP_DigestUpdate(&md, hash, hashlen);
                EVP_DigestUpdate(&md, digest, have);
                EVP_DigestFinal(&md, digest + have, NULL);
        }
@@ -467,19 +498,22 @@ Newkeys *current_keys[MODE_MAX];
 
 #define NKEYS  6
 void
-kex_derive_keys(Kex *kex, u_char *hash, BIGNUM *shared_secret)
+kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
 {
        u_char *keys[NKEYS];
        u_int i, mode, ctos;
 
-       for (i = 0; i < NKEYS; i++)
-               keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, shared_secret);
+       for (i = 0; i < NKEYS; i++) {
+               keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
+                   shared_secret);
+       }
 
        debug2("kex_derive_keys");
        for (mode = 0; mode < MODE_MAX; mode++) {
                current_keys[mode] = kex->newkeys[mode];
                kex->newkeys[mode] = NULL;
-               ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
+               ctos = (!kex->server && mode == MODE_OUT) ||
+                   (kex->server && mode == MODE_IN);
                current_keys[mode]->enc.iv  = keys[ctos ? 0 : 1];
                current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
                current_keys[mode]->mac.key = keys[ctos ? 4 : 5];