+void
+set_newkeys(int mode)
+{
+ Enc *enc;
+ Mac *mac;
+ Comp *comp;
+ CipherContext *cc;
+ u_int64_t *max_blocks;
+ int crypt_type;
+
+ debug2("set_newkeys: mode %d", mode);
+
+ if (mode == MODE_OUT) {
+ cc = &send_context;
+ crypt_type = CIPHER_ENCRYPT;
+ p_send.packets = p_send.blocks = 0;
+ max_blocks = &max_blocks_out;
+ } else {
+ cc = &receive_context;
+ crypt_type = CIPHER_DECRYPT;
+ p_read.packets = p_read.blocks = 0;
+ max_blocks = &max_blocks_in;
+ }
+ if (newkeys[mode] != NULL) {
+ debug("set_newkeys: rekeying");
+ cipher_cleanup(cc);
+ enc = &newkeys[mode]->enc;
+ mac = &newkeys[mode]->mac;
+ comp = &newkeys[mode]->comp;
+ memset(mac->key, 0, mac->key_len);
+ xfree(enc->name);
+ xfree(enc->iv);
+ xfree(enc->key);
+ xfree(mac->name);
+ xfree(mac->key);
+ xfree(comp->name);
+ xfree(newkeys[mode]);
+ }
+ newkeys[mode] = kex_get_newkeys(mode);
+ if (newkeys[mode] == NULL)
+ fatal("newkeys: no keys for mode %d", mode);
+ enc = &newkeys[mode]->enc;
+ mac = &newkeys[mode]->mac;
+ comp = &newkeys[mode]->comp;
+ if (mac->md != NULL)
+ mac->enabled = 1;
+ DBG(debug("cipher_init_context: %d", mode));
+ cipher_init(cc, enc->cipher, enc->key, enc->key_len,
+ enc->iv, enc->block_size, crypt_type);
+ /* Deleting the keys does not gain extra security */
+ /* memset(enc->iv, 0, enc->block_size);
+ memset(enc->key, 0, enc->key_len); */
+ if ((comp->type == COMP_ZLIB ||
+ (comp->type == COMP_DELAYED && after_authentication)) &&
+ comp->enabled == 0) {
+ packet_init_compression();
+ if (mode == MODE_OUT)
+ buffer_compress_init_send(6);
+ else
+ buffer_compress_init_recv();
+ comp->enabled = 1;
+ }
+ /*
+ * The 2^(blocksize*2) limit is too expensive for 3DES,
+ * blowfish, etc, so enforce a 1GB limit for small blocksizes.
+ */
+ if (enc->block_size >= 16)
+ *max_blocks = (u_int64_t)1 << (enc->block_size*2);
+ else
+ *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
+ if (rekey_limit)
+ *max_blocks = MIN(*max_blocks, rekey_limit / enc->block_size);
+}
+
+/*
+ * Delayed compression for SSH2 is enabled after authentication:
+ * This happans on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
+ * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
+ */
+static void
+packet_enable_delayed_compress(void)
+{
+ Comp *comp = NULL;
+ int mode;
+
+ /*
+ * Remember that we are past the authentication step, so rekeying
+ * with COMP_DELAYED will turn on compression immediately.
+ */
+ after_authentication = 1;
+ for (mode = 0; mode < MODE_MAX; mode++) {
+ comp = &newkeys[mode]->comp;
+ if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
+ packet_init_compression();
+ if (mode == MODE_OUT)
+ buffer_compress_init_send(6);
+ else
+ buffer_compress_init_recv();
+ comp->enabled = 1;
+ }
+ }
+}
+