Revert "kex: server fix for first_kex_packet_follows"

The patch breaks the client with ECDSA.

This reverts commit 5865b9436fda96ac9fc7c18e4dffe5fb12dcc515.

1 files changed, 171 insertions, 187 deletions

diff --git a/src/dh.c b/src/dh.c
index 3255ac75..ca2c2bf9 100644
--- a/src/dh.c
+++ b/src/dh.c
@@ -587,234 +587,218 @@ error:
   return SSH_ERROR;
 }
 
+
+/*
+static void sha_add(ssh_string str,SHACTX ctx){
+    sha1_update(ctx,str,string_len(str)+4);
+#ifdef DEBUG_CRYPTO
+    ssh_print_hexa("partial hashed sessionid",str,string_len(str)+4);
+#endif
+}
+*/
+
 int make_sessionid(ssh_session session) {
-    ssh_string num = NULL;
-    ssh_string str = NULL;
-    ssh_buffer server_hash = NULL;
-    ssh_buffer client_hash = NULL;
-    ssh_buffer buf = NULL;
-    uint32_t len;
-    int rc = SSH_ERROR;
-
-    buf = ssh_buffer_new();
-    if (buf == NULL) {
-        return rc;
-    }
+  ssh_string num = NULL;
+  ssh_string str = NULL;
+  ssh_buffer server_hash = NULL;
+  ssh_buffer client_hash = NULL;
+  ssh_buffer buf = NULL;
+  uint32_t len;
+  int rc = SSH_ERROR;
+
+  buf = ssh_buffer_new();
+  if (buf == NULL) {
+    return rc;
+  }
 
-    str = ssh_string_from_char(session->clientbanner);
-    if (str == NULL) {
-        goto error;
-    }
+  str = ssh_string_from_char(session->clientbanner);
+  if (str == NULL) {
+    goto error;
+  }
 
-    rc = buffer_add_ssh_string(buf, str);
-    if (rc < 0) {
-        goto error;
-    }
-    ssh_string_free(str);
+  if (buffer_add_ssh_string(buf, str) < 0) {
+    goto error;
+  }
+  ssh_string_free(str);
 
-    str = ssh_string_from_char(session->serverbanner);
-    if (str == NULL) {
-        goto error;
-    }
+  str = ssh_string_from_char(session->serverbanner);
+  if (str == NULL) {
+    goto error;
+  }
 
-    rc = buffer_add_ssh_string(buf, str);
-    if (rc < 0) {
-        goto error;
-    }
+  if (buffer_add_ssh_string(buf, str) < 0) {
+    goto error;
+  }
 
-    if (session->client) {
-        server_hash = session->in_hashbuf;
-        client_hash = session->out_hashbuf;
-    } else {
-        server_hash = session->out_hashbuf;
-        client_hash = session->in_hashbuf;
-    }
+  if (session->client) {
+    server_hash = session->in_hashbuf;
+    client_hash = session->out_hashbuf;
+  } else {
+    server_hash = session->out_hashbuf;
+    client_hash = session->in_hashbuf;
+  }
 
-    /*
-     * Handle the two final fields for the KEXINIT message (RFC 4253 7.1):
-     *
-     *      boolean      first_kex_packet_follows
-     *      uint32       0 (reserved for future extension)
-     */
-    rc = buffer_add_u8(server_hash, 0);
-    if (rc < 0) {
-        goto error;
-    }
-    rc = buffer_add_u32(server_hash, 0);
-    if (rc < 0) {
-        goto error;
+  if (buffer_add_u32(server_hash, 0) < 0) {
+    goto error;
+  }
+  if (buffer_add_u8(server_hash, 0) < 0) {
+    goto error;
+  }
+  if (buffer_add_u32(client_hash, 0) < 0) {
+    goto error;
+  }
+  if (buffer_add_u8(client_hash, 0) < 0) {
+    goto error;
+  }
+
+  len = ntohl(buffer_get_rest_len(client_hash));
+  if (buffer_add_u32(buf,len) < 0) {
+    goto error;
+  }
+  if (ssh_buffer_add_data(buf, buffer_get_rest(client_hash),
+        buffer_get_rest_len(client_hash)) < 0) {
+    goto error;
+  }
+
+  len = ntohl(buffer_get_rest_len(server_hash));
+  if (buffer_add_u32(buf, len) < 0) {
+    goto error;
+  }
+  if (ssh_buffer_add_data(buf, buffer_get_rest(server_hash),
+        buffer_get_rest_len(server_hash)) < 0) {
+    goto error;
+  }
+
+  len = ssh_string_len(session->next_crypto->server_pubkey) + 4;
+  if (ssh_buffer_add_data(buf, session->next_crypto->server_pubkey, len) < 0) {
+    goto error;
+  }
+  if(session->next_crypto->kex_type == SSH_KEX_DH_GROUP1_SHA1 ||
+     session->next_crypto->kex_type == SSH_KEX_DH_GROUP14_SHA1) {
+
+    num = make_bignum_string(session->next_crypto->e);
+    if (num == NULL) {
+      goto error;
     }
 
-    /* These fields are handled for the server case in ssh_packet_kexinit. */
-    if (session->client) {
-        rc = buffer_add_u8(client_hash, 0);
-        if (rc < 0) {
-            goto error;
-        }
-        rc = buffer_add_u32(client_hash, 0);
-        if (rc < 0) {
-            goto error;
-        }
+    len = ssh_string_len(num) + 4;
+    if (ssh_buffer_add_data(buf, num, len) < 0) {
+      goto error;
     }
 
-    len = ntohl(buffer_get_rest_len(client_hash));
-    rc = buffer_add_u32(buf,len);
-    if (rc < 0) {
-        goto error;
+    ssh_string_free(num);
+    num = make_bignum_string(session->next_crypto->f);
+    if (num == NULL) {
+      goto error;
     }
-    rc = ssh_buffer_add_data(buf, buffer_get_rest(client_hash),
-                              buffer_get_rest_len(client_hash));
-    if (rc < 0) {
-        goto error;
+
+    len = ssh_string_len(num) + 4;
+    if (ssh_buffer_add_data(buf, num, len) < 0) {
+      goto error;
     }
 
-    len = ntohl(buffer_get_rest_len(server_hash));
-    rc = buffer_add_u32(buf, len);
-    if (rc < 0) {
+    ssh_string_free(num);
+#ifdef HAVE_ECDH
+  } else if (session->next_crypto->kex_type == SSH_KEX_ECDH_SHA2_NISTP256){
+    if(session->next_crypto->ecdh_client_pubkey == NULL ||
+            session->next_crypto->ecdh_server_pubkey == NULL){
+        SSH_LOG(SSH_LOG_WARNING, "ECDH parameted missing");
         goto error;
     }
-    rc = ssh_buffer_add_data(buf, buffer_get_rest(server_hash),
-                                  buffer_get_rest_len(server_hash));
+    rc = buffer_add_ssh_string(buf,session->next_crypto->ecdh_client_pubkey);
     if (rc < 0) {
         goto error;
     }
-
-    len = ssh_string_len(session->next_crypto->server_pubkey) + 4;
-    rc = ssh_buffer_add_data(buf, session->next_crypto->server_pubkey, len);
+    rc = buffer_add_ssh_string(buf,session->next_crypto->ecdh_server_pubkey);
     if (rc < 0) {
         goto error;
     }
-
-    if (session->next_crypto->kex_type == SSH_KEX_DH_GROUP1_SHA1 ||
-        session->next_crypto->kex_type == SSH_KEX_DH_GROUP14_SHA1) {
-
-        num = make_bignum_string(session->next_crypto->e);
-        if (num == NULL) {
-            goto error;
-        }
-
-        len = ssh_string_len(num) + 4;
-        rc = ssh_buffer_add_data(buf, num, len);
-        if (rc < 0) {
-            goto error;
-        }
-
-        ssh_string_free(num);
-        num = make_bignum_string(session->next_crypto->f);
-        if (num == NULL) {
-            goto error;
-        }
-
-        len = ssh_string_len(num) + 4;
-        rc = ssh_buffer_add_data(buf, num, len);
-        if (rc < 0) {
-          goto error;
-        }
-
-        ssh_string_free(num);
-#ifdef HAVE_ECDH
-    } else if (session->next_crypto->kex_type == SSH_KEX_ECDH_SHA2_NISTP256) {
-        if (session->next_crypto->ecdh_client_pubkey == NULL ||
-            session->next_crypto->ecdh_server_pubkey == NULL) {
-            SSH_LOG(SSH_LOG_WARNING, "ECDH parameted missing");
-            goto error;
-        }
-        rc = buffer_add_ssh_string(buf,session->next_crypto->ecdh_client_pubkey);
-        if (rc < 0) {
-            goto error;
-        }
-        rc = buffer_add_ssh_string(buf,session->next_crypto->ecdh_server_pubkey);
-        if (rc < 0) {
-            goto error;
-        }
 #endif
 #ifdef HAVE_CURVE25519
-    } else if (session->next_crypto->kex_type == SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG) {
-        rc = buffer_add_u32(buf, htonl(CURVE25519_PUBKEY_SIZE));
-        rc += ssh_buffer_add_data(buf, session->next_crypto->curve25519_client_pubkey,
-                                       CURVE25519_PUBKEY_SIZE);
-        rc += buffer_add_u32(buf, htonl(CURVE25519_PUBKEY_SIZE));
-        rc += ssh_buffer_add_data(buf, session->next_crypto->curve25519_server_pubkey,
-                                       CURVE25519_PUBKEY_SIZE);
-        if (rc != SSH_OK) {
-                goto error;
-        }
+  } else if(session->next_crypto->kex_type == SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG){
+	  rc = buffer_add_u32(buf, htonl(CURVE25519_PUBKEY_SIZE));
+	  rc += ssh_buffer_add_data(buf, session->next_crypto->curve25519_client_pubkey,
+			  CURVE25519_PUBKEY_SIZE);
+	  rc += buffer_add_u32(buf, htonl(CURVE25519_PUBKEY_SIZE));
+	  rc += ssh_buffer_add_data(buf, session->next_crypto->curve25519_server_pubkey,
+			  CURVE25519_PUBKEY_SIZE);
+	  if (rc != SSH_OK) {
+		  goto error;
+      }
 #endif
-    }
-
-    num = make_bignum_string(session->next_crypto->k);
-    if (num == NULL) {
-        goto error;
-    }
+  }
+  num = make_bignum_string(session->next_crypto->k);
+  if (num == NULL) {
+    goto error;
+  }
 
-    len = ssh_string_len(num) + 4;
-    rc = ssh_buffer_add_data(buf, num, len);
-    if (rc < 0) {
-        goto error;
-    }
+  len = ssh_string_len(num) + 4;
+  if (ssh_buffer_add_data(buf, num, len) < 0) {
+    goto error;
+  }
 
 #ifdef DEBUG_CRYPTO
-    ssh_print_hexa("hash buffer", ssh_buffer_get_begin(buf), ssh_buffer_get_len(buf));
+  ssh_print_hexa("hash buffer", ssh_buffer_get_begin(buf), ssh_buffer_get_len(buf));
 #endif
 
-    switch (session->next_crypto->kex_type) {
+  switch(session->next_crypto->kex_type){
     case SSH_KEX_DH_GROUP1_SHA1:
     case SSH_KEX_DH_GROUP14_SHA1:
-        session->next_crypto->digest_len = SHA_DIGEST_LENGTH;
-        session->next_crypto->mac_type = SSH_MAC_SHA1;
-        session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
-        if (session->next_crypto->secret_hash == NULL) {
-            ssh_set_error_oom(session);
-            goto error;
-        }
-        sha1(buffer_get_rest(buf), buffer_get_rest_len(buf),
-                                   session->next_crypto->secret_hash);
-        break;
+      session->next_crypto->digest_len = SHA_DIGEST_LENGTH;
+      session->next_crypto->mac_type = SSH_MAC_SHA1;
+      session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
+      if(session->next_crypto->secret_hash == NULL){
+        ssh_set_error_oom(session);
+        goto error;
+      }
+      sha1(buffer_get_rest(buf), buffer_get_rest_len(buf),
+                session->next_crypto->secret_hash);
+      break;
     case SSH_KEX_ECDH_SHA2_NISTP256:
     case SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG:
-        session->next_crypto->digest_len = SHA256_DIGEST_LENGTH;
-        session->next_crypto->mac_type = SSH_MAC_SHA256;
-        session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
-        if (session->next_crypto->secret_hash == NULL) {
-            ssh_set_error_oom(session);
-            goto error;
-        }
-        sha256(buffer_get_rest(buf), buffer_get_rest_len(buf),
-                                     session->next_crypto->secret_hash);
-        break;
-    }
-    /* During the first kex, secret hash and session ID are equal. However, after
-     * a key re-exchange, a new secret hash is calculated. This hash will not replace
-     * but complement existing session id.
-     */
-    if (!session->next_crypto->session_id) {
-        session->next_crypto->session_id = malloc(session->next_crypto->digest_len);
-        if (session->next_crypto->session_id == NULL) {
-            ssh_set_error_oom(session);
-            goto error;
-        }
-        memcpy(session->next_crypto->session_id, session->next_crypto->secret_hash,
-                session->next_crypto->digest_len);
-    }
+      session->next_crypto->digest_len = SHA256_DIGEST_LENGTH;
+      session->next_crypto->mac_type = SSH_MAC_SHA256;
+      session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
+      if(session->next_crypto->secret_hash == NULL){
+        ssh_set_error_oom(session);
+        goto error;
+      }
+      sha256(buffer_get_rest(buf), buffer_get_rest_len(buf),
+          session->next_crypto->secret_hash);
+      break;
+  }
+  /* During the first kex, secret hash and session ID are equal. However, after
+   * a key re-exchange, a new secret hash is calculated. This hash will not replace
+   * but complement existing session id.
+   */
+  if (!session->next_crypto->session_id){
+      session->next_crypto->session_id = malloc(session->next_crypto->digest_len);
+      if (session->next_crypto->session_id == NULL){
+          ssh_set_error_oom(session);
+          goto error;
+      }
+      memcpy(session->next_crypto->session_id, session->next_crypto->secret_hash,
+              session->next_crypto->digest_len);
+  }
 #ifdef DEBUG_CRYPTO
-    printf("Session hash: \n");
-    ssh_print_hexa("secret hash", session->next_crypto->secret_hash, session->next_crypto->digest_len);
-    ssh_print_hexa("session id", session->next_crypto->session_id, session->next_crypto->digest_len);
+  printf("Session hash: \n");
+  ssh_print_hexa("secret hash", session->next_crypto->secret_hash, session->next_crypto->digest_len);
+  ssh_print_hexa("session id", session->next_crypto->session_id, session->next_crypto->digest_len);
 #endif
 
-    rc = SSH_OK;
+  rc = SSH_OK;
 error:
-    ssh_buffer_free(buf);
-    ssh_buffer_free(client_hash);
-    ssh_buffer_free(server_hash);
+  ssh_buffer_free(buf);
+  ssh_buffer_free(client_hash);
+  ssh_buffer_free(server_hash);
 
-    session->in_hashbuf = NULL;
-    session->out_hashbuf = NULL;
+  session->in_hashbuf = NULL;
+  session->out_hashbuf = NULL;
 
-    ssh_string_free(str);
-    ssh_string_free(num);
+  ssh_string_free(str);
+  ssh_string_free(num);
 
-    return rc;
+  return rc;
 }
 
 int hashbufout_add_cookie(ssh_session session) {