crypto: Change the type of server_pubkey to ssh_key

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>

include/libssh/crypto.h

@@ -109,8 +109,7 @@ struct ssh_crypto_struct {
     struct ssh_cipher_struct *in_cipher, *out_cipher; /* the cipher structures/objects */
     enum ssh_hmac_e in_hmac, out_hmac; /* the MAC algorithms used */
 
-    ssh_string server_pubkey;
-    const char *server_pubkey_type;
+    ssh_key server_pubkey;
     int do_compress_out; /* idem */
     int do_compress_in; /* don't set them, set the option instead */
     int delayed_compress_in; /* Use of zlib@openssh.org */

include/libssh/dh.h

@@ -37,11 +37,21 @@ ssh_string ssh_dh_get_e(ssh_session session);
 ssh_string ssh_dh_get_f(ssh_session session);
 int ssh_dh_import_f(ssh_session session,ssh_string f_string);
 int ssh_dh_import_e(ssh_session session, ssh_string e_string);
-void ssh_dh_import_pubkey(ssh_session session,ssh_string pubkey_string);
+
+int ssh_dh_import_pubkey_blob(ssh_session session, ssh_string pubkey_blob);
+int ssh_dh_import_next_pubkey_blob(ssh_session session, ssh_string pubkey_blob);
+
 int ssh_dh_build_k(ssh_session session);
 int ssh_client_dh_init(ssh_session session);
 int ssh_client_dh_reply(ssh_session session, ssh_buffer packet);
 
+ssh_key ssh_dh_get_current_server_publickey(ssh_session session);
+int ssh_dh_get_current_server_publickey_blob(ssh_session session,
+                                             ssh_string *pubkey_blob);
+ssh_key ssh_dh_get_next_server_publickey(ssh_session session);
+int ssh_dh_get_next_server_publickey_blob(ssh_session session,
+                                          ssh_string *pubkey_blob);
+
 int ssh_make_sessionid(ssh_session session);
 /* add data for the final cookie */
 int ssh_hashbufin_add_cookie(ssh_session session, unsigned char *cookie);

src/curve25519.c

@@ -118,17 +118,24 @@ static int ssh_curve25519_build_k(ssh_session session) {
  */
 int ssh_client_curve25519_reply(ssh_session session, ssh_buffer packet){
   ssh_string q_s_string = NULL;
-  ssh_string pubkey = NULL;
+  ssh_string pubkey_blob = NULL;
   ssh_string signature = NULL;
   int rc;
-  pubkey = ssh_buffer_get_ssh_string(packet);
-  if (pubkey == NULL){
+
+  pubkey_blob = ssh_buffer_get_ssh_string(packet);
+  if (pubkey_blob == NULL) {
     ssh_set_error(session,SSH_FATAL, "No public key in packet");
     goto error;
   }
-  /* this is the server host key */
-  session->next_crypto->server_pubkey = pubkey;
-  pubkey = NULL;
+
+  rc = ssh_dh_import_next_pubkey_blob(session, pubkey_blob);
+  ssh_string_free(pubkey_blob);
+  if (rc != 0) {
+      ssh_set_error(session,
+                    SSH_FATAL,
+                    "Failed to import next public key");
+      goto error;
+  }
 
   q_s_string = ssh_buffer_get_ssh_string(packet);
   if (q_s_string == NULL) {
@@ -178,6 +185,7 @@ int ssh_server_curve25519_init(ssh_session session, ssh_buffer packet){
     /* ECDH keys */
     ssh_string q_c_string;
     ssh_string q_s_string;
+    ssh_string server_pubkey_blob = NULL;
 
     /* SSH host keys (rsa,dsa,ecdsa) */
     ssh_key privkey;
@@ -236,9 +244,16 @@ int ssh_server_curve25519_init(ssh_session session, ssh_buffer packet){
         goto error;
     }
 
+    rc = ssh_dh_get_next_server_publickey_blob(session, &server_pubkey_blob);
+    if (rc != 0) {
+        ssh_set_error(session, SSH_FATAL, "Could not export server public key");
+        goto error;
+    }
+
     /* add host's public key */
     rc = ssh_buffer_add_ssh_string(session->out_buffer,
-                               session->next_crypto->server_pubkey);
+                                   server_pubkey_blob);
+    ssh_string_free(server_pubkey_blob);
     if (rc < 0) {
         ssh_set_error_oom(session);
         goto error;

src/dh.c

@@ -387,8 +387,17 @@ ssh_string ssh_dh_get_f(ssh_session session) {
   return ssh_make_bignum_string(session->next_crypto->f);
 }
 
-void ssh_dh_import_pubkey(ssh_session session, ssh_string pubkey_string) {
-  session->next_crypto->server_pubkey = pubkey_string;
+int ssh_dh_import_pubkey_blob(ssh_session session, ssh_string pubkey_blob)
+{
+    return ssh_pki_import_pubkey_blob(pubkey_blob,
+                                      &session->current_crypto->server_pubkey);
+}
+
+int ssh_dh_import_next_pubkey_blob(ssh_session session, ssh_string pubkey_blob)
+{
+    return ssh_pki_import_pubkey_blob(pubkey_blob,
+                                      &session->next_crypto->server_pubkey);
+
 }
 
 int ssh_dh_import_f(ssh_session session, ssh_string f_string) {
@@ -517,15 +526,21 @@ int ssh_client_dh_init(ssh_session session){
 
 int ssh_client_dh_reply(ssh_session session, ssh_buffer packet){
   ssh_string f;
-  ssh_string pubkey = NULL;
+  ssh_string pubkey_blob = NULL;
   ssh_string signature = NULL;
   int rc;
-  pubkey = ssh_buffer_get_ssh_string(packet);
-  if (pubkey == NULL){
+
+  pubkey_blob = ssh_buffer_get_ssh_string(packet);
+  if (pubkey_blob == NULL){
     ssh_set_error(session,SSH_FATAL, "No public key in packet");
     goto error;
   }
-  ssh_dh_import_pubkey(session, pubkey);
+
+  rc = ssh_dh_import_next_pubkey_blob(session, pubkey_blob);
+  ssh_string_free(pubkey_blob);
+  if (rc != 0) {
+      goto error;
+  }
 
   f = ssh_buffer_get_ssh_string(packet);
   if (f == NULL) {
@@ -569,6 +584,7 @@ int ssh_make_sessionid(ssh_session session) {
     ssh_buffer server_hash = NULL;
     ssh_buffer client_hash = NULL;
     ssh_buffer buf = NULL;
+    ssh_string server_pubkey_blob = NULL;
     int rc = SSH_ERROR;
 
     buf = ssh_buffer_new();
@@ -619,6 +635,11 @@ int ssh_make_sessionid(ssh_session session) {
         }
     }
 
+    rc = ssh_dh_get_next_server_publickey_blob(session, &server_pubkey_blob);
+    if (rc != SSH_OK) {
+        goto error;
+    }
+
     rc = ssh_buffer_pack(buf,
                          "dPdPS",
                          ssh_buffer_get_len(client_hash),
@@ -627,8 +648,8 @@ int ssh_make_sessionid(ssh_session session) {
                          ssh_buffer_get_len(server_hash),
                          ssh_buffer_get_len(server_hash),
                          ssh_buffer_get(server_hash),
-                         session->next_crypto->server_pubkey);
-
+                         server_pubkey_blob);
+    ssh_string_free(server_pubkey_blob);
     if(rc != SSH_OK){
         goto error;
     }
@@ -959,9 +980,11 @@ error:
  * @deprecated Use ssh_get_publickey_hash()
  */
 int ssh_get_pubkey_hash(ssh_session session, unsigned char **hash) {
-  ssh_string pubkey;
+  ssh_key pubkey = NULL;
+  ssh_string pubkey_blob = NULL;
   MD5CTX ctx;
   unsigned char *h;
+  int rc;
 
   if (session == NULL || hash == NULL) {
     return SSH_ERROR;
@@ -984,9 +1007,19 @@ int ssh_get_pubkey_hash(ssh_session session, unsigned char **hash) {
     return SSH_ERROR;
   }
 
-  pubkey = session->current_crypto->server_pubkey;
+  rc = ssh_get_server_publickey(session, &pubkey);
+  if (rc != 0) {
+    SAFE_FREE(h);
+    return SSH_ERROR;
+  }
 
-  md5_update(ctx, ssh_string_data(pubkey), ssh_string_len(pubkey));
+  rc = ssh_pki_export_pubkey_blob(pubkey,
+                                  &pubkey_blob);
+  ssh_key_free(pubkey);
+  if (rc != 0) {
+  }
+  md5_update(ctx, ssh_string_data(pubkey_blob), ssh_string_len(pubkey_blob));
+  ssh_string_free(pubkey_blob);
   md5_final(h, ctx);
 
   *hash = h;
@@ -1023,14 +1056,49 @@ void ssh_clean_pubkey_hash(unsigned char **hash) {
  */
 int ssh_get_server_publickey(ssh_session session, ssh_key *key)
 {
-    if (session==NULL ||
-        session->current_crypto ==NULL ||
+    ssh_key pubkey = NULL;
+
+    if (session == NULL ||
+        session->current_crypto == NULL ||
         session->current_crypto->server_pubkey == NULL) {
         return SSH_ERROR;
     }
 
-    return ssh_pki_import_pubkey_blob(session->current_crypto->server_pubkey,
-                                      key);
+    pubkey = ssh_key_dup(session->current_crypto->server_pubkey);
+    if (pubkey == NULL) {
+        return SSH_ERROR;
+    }
+
+    *key = pubkey;
+    return SSH_OK;
+}
+
+ssh_key ssh_dh_get_current_server_publickey(ssh_session session)
+{
+    return session->current_crypto->server_pubkey;
+}
+
+/* Caller need to free the blob */
+int ssh_dh_get_current_server_publickey_blob(ssh_session session,
+                                     ssh_string *pubkey_blob)
+{
+    const ssh_key pubkey = ssh_dh_get_current_server_publickey(session);
+
+    return ssh_pki_export_pubkey_blob(pubkey, pubkey_blob);
+}
+
+ssh_key ssh_dh_get_next_server_publickey(ssh_session session)
+{
+    return session->next_crypto->server_pubkey;
+}
+
+/* Caller need to free the blob */
+int ssh_dh_get_next_server_publickey_blob(ssh_session session,
+                                          ssh_string *pubkey_blob)
+{
+    const ssh_key pubkey = ssh_dh_get_next_server_publickey(session);
+
+    return ssh_pki_export_pubkey_blob(pubkey, pubkey_blob);
 }
 
 /**

src/ecdh.c

@@ -30,25 +30,27 @@
 
 #ifdef HAVE_ECDH
 
-static void ecdh_import_pubkey(ssh_session session, ssh_string pubkey_string) {
-  session->next_crypto->server_pubkey = pubkey_string;
-}
-
 /** @internal
  * @brief parses a SSH_MSG_KEX_ECDH_REPLY packet and sends back
  * a SSH_MSG_NEWKEYS
  */
 int ssh_client_ecdh_reply(ssh_session session, ssh_buffer packet){
   ssh_string q_s_string = NULL;
-  ssh_string pubkey = NULL;
+  ssh_string pubkey_blob = NULL;
   ssh_string signature = NULL;
   int rc;
-  pubkey = ssh_buffer_get_ssh_string(packet);
-  if (pubkey == NULL){
+
+  pubkey_blob = ssh_buffer_get_ssh_string(packet);
+  if (pubkey_blob == NULL) {
     ssh_set_error(session,SSH_FATAL, "No public key in packet");
     goto error;
   }
-  ecdh_import_pubkey(session, pubkey);
+
+  rc = ssh_dh_import_next_pubkey_blob(session, pubkey_blob);
+  ssh_string_free(pubkey_blob);
+  if (rc != 0) {
+      goto error;
+  }
 
   q_s_string = ssh_buffer_get_ssh_string(packet);
   if (q_s_string == NULL) {

src/known_hosts.c

@@ -32,6 +32,7 @@
 #include "libssh/session.h"
 #include "libssh/buffer.h"
 #include "libssh/misc.h"
+#include "libssh/dh.h"
 #include "libssh/pki.h"
 #include "libssh/options.h"
 #include "libssh/knownhosts.h"
@@ -188,9 +189,10 @@ static char **ssh_get_knownhost_line(FILE **file, const char *filename,
  *                      on error.
  */
 static int check_public_key(ssh_session session, char **tokens) {
-  ssh_string pubkey = session->current_crypto->server_pubkey;
+  ssh_string pubkey_blob = NULL;
   ssh_buffer pubkey_buffer;
   char *pubkey_64;
+  int rc;
 
   /* ok we found some public key in known hosts file. now un-base64it */
   if (alldigits(tokens[1])) {
@@ -270,18 +272,26 @@ static int check_public_key(ssh_session session, char **tokens) {
     return -1;
   }
 
-  if (ssh_buffer_get_len(pubkey_buffer) != ssh_string_len(pubkey)) {
+  rc = ssh_dh_get_current_server_publickey_blob(session, &pubkey_blob);
+  if (rc != 0) {
+      return -1;
+  }
+
+  if (ssh_buffer_get_len(pubkey_buffer) != ssh_string_len(pubkey_blob)) {
+    ssh_string_free(pubkey_blob);
     ssh_buffer_free(pubkey_buffer);
     return 0;
   }
 
   /* now test that they are identical */
-  if (memcmp(ssh_buffer_get(pubkey_buffer), ssh_string_data(pubkey),
+  if (memcmp(ssh_buffer_get(pubkey_buffer), ssh_string_data(pubkey_blob),
         ssh_buffer_get_len(pubkey_buffer)) != 0) {
+    ssh_string_free(pubkey_blob);
     ssh_buffer_free(pubkey_buffer);
     return 0;
   }
 
+  ssh_string_free(pubkey_blob);
   ssh_buffer_free(pubkey_buffer);
   return 1;
 }
@@ -485,12 +495,21 @@ int ssh_is_server_known(ssh_session session) {
       match = match_hashed_host(hostport, tokens[0]);
     }
     if (match) {
+      ssh_key pubkey = ssh_dh_get_current_server_publickey(session);
+      const char *pubkey_type = NULL;
+
+      if (ssh_key_type(pubkey) == SSH_KEYTYPE_ECDSA) {
+          pubkey_type = ssh_pki_key_ecdsa_name(pubkey);
+      } else {
+        pubkey_type = ssh_key_type_to_char(ssh_key_type(pubkey));
+      }
+
       /* We got a match. Now check the key type */
-      if (strcmp(session->current_crypto->server_pubkey_type, type) != 0) {
+      if (strcmp(pubkey_type, type) != 0) {
           SSH_LOG(SSH_LOG_PACKET,
                   "ssh_is_server_known: server type [%s] doesn't match the "
                   "type [%s] in known_hosts file",
-                  session->current_crypto->server_pubkey_type,
+                  pubkey_type,
                   type);
         /* Different type. We don't override the known_changed error which is
          * more important */
@@ -545,8 +564,7 @@ int ssh_is_server_known(ssh_session session) {
  * @return              string on success, NULL on error.
  */
 char * ssh_dump_knownhost(ssh_session session) {
-    ssh_string pubkey_s;
-    ssh_key key;
+    ssh_key server_pubkey = NULL;
     char *host;
     char *hostport;
     size_t len = 4096;
@@ -578,40 +596,31 @@ char * ssh_dump_knownhost(ssh_session session) {
         return NULL;
     }
 
-    pubkey_s = session->current_crypto->server_pubkey;
-    if (pubkey_s == NULL){
+    server_pubkey = ssh_dh_get_current_server_publickey(session);
+    if (server_pubkey == NULL){
         ssh_set_error(session, SSH_FATAL, "No public key present");
         SAFE_FREE(host);
         return NULL;
     }
 
-    rc = ssh_pki_import_pubkey_blob(pubkey_s, &key);
-    if (rc < 0) {
-        SAFE_FREE(host);
-        return NULL;
-    }
-
     buffer = calloc (1, 4096);
     if (!buffer) {
-        ssh_key_free(key);
         SAFE_FREE(host);
         return NULL;
     }
 
-    if (strcmp(session->current_crypto->server_pubkey_type, "ssh-rsa1") == 0) {
+    if (ssh_key_type(server_pubkey) == SSH_KEYTYPE_RSA1) {
         /* openssh uses a different format for ssh-rsa1 keys.
            Be compatible --kv */
-        rc = ssh_pki_export_pubkey_rsa1(key, host, buffer, len);
-        ssh_key_free(key);
+        rc = ssh_pki_export_pubkey_rsa1(server_pubkey, host, buffer, len);
         SAFE_FREE(host);
         if (rc < 0) {
             SAFE_FREE(buffer);
             return NULL;
         }
     } else {
-        rc = ssh_pki_export_pubkey_base64(key, &b64_key);
+        rc = ssh_pki_export_pubkey_base64(server_pubkey, &b64_key);
         if (rc < 0) {
-            ssh_key_free(key);
             SAFE_FREE(buffer);
             SAFE_FREE(host);
             return NULL;
@@ -620,10 +629,9 @@ char * ssh_dump_knownhost(ssh_session session) {
         snprintf(buffer, len,
                 "%s %s %s\n",
                 host,
-                key->type_c,
+                server_pubkey->type_c,
                 b64_key);
 
-        ssh_key_free(key);
         SAFE_FREE(host);
         SAFE_FREE(b64_key);
     }

src/legacy.c

@@ -33,6 +33,7 @@
 #include <libssh/session.h>
 #include <libssh/server.h>
 #include <libssh/buffer.h>
+#include <libssh/dh.h>
 #include <libssh/pki.h>
 #include "libssh/pki_priv.h"
 #include <libssh/misc.h>
@@ -701,12 +702,24 @@ int ssh_try_publickey_from_file(ssh_session session,
     return 0;
 }
 
-ssh_string ssh_get_pubkey(ssh_session session){
-	if(session==NULL || session->current_crypto ==NULL ||
-      session->current_crypto->server_pubkey==NULL)
-    return NULL;
-	else
-    return ssh_string_copy(session->current_crypto->server_pubkey);
+ssh_string ssh_get_pubkey(ssh_session session)
+{
+    ssh_string pubkey_blob = NULL;
+    int rc;
+
+    if (session == NULL ||
+        session->current_crypto == NULL ||
+        session->current_crypto->server_pubkey == NULL) {
+        return NULL;
+    }
+
+    rc = ssh_dh_get_current_server_publickey_blob(session,
+                                                  &pubkey_blob);
+    if (rc != 0) {
+        return NULL;
+    }
+
+    return pubkey_blob;
 }
 
 /****************************************************************************

src/packet_cb.c

@@ -154,7 +154,8 @@ SSH_PACKET_CALLBACK(ssh_packet_newkeys){
     /* server things are done in server.c */
     session->dh_handshake_state=DH_STATE_FINISHED;
   } else {
-    ssh_key key;
+    ssh_key server_key;
+
     /* client */
     rc = ssh_make_sessionid(session);
     if (rc != SSH_OK) {
@@ -178,7 +179,7 @@ SSH_PACKET_CALLBACK(ssh_packet_newkeys){
     session->next_crypto->dh_server_signature = NULL;
 
     /* get the server public key */
-    rc = ssh_pki_import_pubkey_blob(session->next_crypto->server_pubkey, &key);
+    server_key = ssh_dh_get_next_server_publickey(session);
     if (rc < 0) {
         return SSH_ERROR;
     }
@@ -186,27 +187,22 @@ SSH_PACKET_CALLBACK(ssh_packet_newkeys){
     /* check if public key from server matches user preferences */
     if (session->opts.wanted_methods[SSH_HOSTKEYS]) {
         if(!ssh_match_group(session->opts.wanted_methods[SSH_HOSTKEYS],
-                            key->type_c)) {
+                            server_key->type_c)) {
             ssh_set_error(session,
                           SSH_FATAL,
                           "Public key from server (%s) doesn't match user "
                           "preference (%s)",
-                          key->type_c,
+                          server_key->type_c,
                           session->opts.wanted_methods[SSH_HOSTKEYS]);
-            ssh_key_free(key);
             return -1;
         }
     }
 
     rc = ssh_pki_signature_verify_blob(session,
                                        sig_blob,
-                                       key,
+                                       server_key,
                                        session->next_crypto->secret_hash,
                                        session->next_crypto->digest_len);
-    /* Set the server public key type for known host checking */
-    session->next_crypto->server_pubkey_type = key->type_c;
-
-    ssh_key_free(key);
     ssh_string_burn(sig_blob);
     ssh_string_free(sig_blob);
     sig_blob = NULL;

src/server.c

@@ -277,7 +277,14 @@ int ssh_get_key_params(ssh_session session, ssh_key *privkey){
       return -1;
     }
 
-    ssh_dh_import_pubkey(session, pubkey_blob);
+    rc = ssh_dh_import_pubkey_blob(session, pubkey_blob);
+    if (rc != 0) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Could not import server public key");
+        return -1;
+    }
+
     return SSH_OK;
 }