stcp: ed25519 pubkey exchange in handshake, fix instance destroy segfault, fix chat_tcp_test

- u_async.c: process immediate_queue BEFORE epoll_wait in uasync_poll
- stcp_link.c: defensive NULL etcp_conn/etcp_link in stcp_link_close
- utun_instance.c: move stcp_server_list_destroy_all to Phase J (before ETCP),
  add deferred drain in both Phase J and L
- stcp.h/c: STCP_HS_ENC_CLIENT 6→38, STCP_HS_ENC_SERVER 7→39,
  exchange ed25519_pubkey in both handshake directions
- etcp_connections.c: copy peer_ed25519 from STCP to ETCP_CONN in
  etcp_link_enter_ready_tcp; guard link->etcp in tcp_link_close_cb
- chat_sync.c: fix lk->conn NULL dereference for TCP links
- test_stcp.c: update stcp_server_create/stcp_client_connect callsites
- tools/chat_tcp_test: change transport udp→tcp

tinycrypt/lib/source/ctr_mode.c

@@ -0,0 +1,85 @@
+/* ctr_mode.c - TinyCrypt CTR mode implementation */
+
+/*
+ *  Copyright (C) 2017 by Intel Corporation, All Rights Reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *
+ *    - Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *
+ *    - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ *    - Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <tinycrypt/constants.h>
+#include <tinycrypt/ctr_mode.h>
+#include <tinycrypt/utils.h>
+
+int tc_ctr_mode(uint8_t *out, unsigned int outlen, const uint8_t *in,
+		unsigned int inlen, uint8_t *ctr, const TCAesKeySched_t sched)
+{
+
+	uint8_t buffer[TC_AES_BLOCK_SIZE];
+	uint8_t nonce[TC_AES_BLOCK_SIZE];
+	unsigned int block_num;
+	unsigned int i;
+
+	/* input sanity check: */
+	if (out == (uint8_t *) 0 ||
+	    in == (uint8_t *) 0 ||
+	    ctr == (uint8_t *) 0 ||
+	    sched == (TCAesKeySched_t) 0 ||
+	    inlen == 0 ||
+	    outlen == 0 ||
+	    outlen != inlen) {
+		return TC_CRYPTO_FAIL;
+	}
+
+	/* copy the ctr to the nonce */
+	(void)_copy(nonce, sizeof(nonce), ctr, sizeof(nonce));
+
+	/* select the last 4 bytes of the nonce to be incremented */
+	block_num = (nonce[12] << 24) | (nonce[13] << 16) |
+		    (nonce[14] << 8) | (nonce[15]);
+	for (i = 0; i < inlen; ++i) {
+		if ((i % (TC_AES_BLOCK_SIZE)) == 0) {
+			/* encrypt data using the current nonce */
+			if (tc_aes_encrypt(buffer, nonce, sched)) {
+				block_num++;
+				nonce[12] = (uint8_t)(block_num >> 24);
+				nonce[13] = (uint8_t)(block_num >> 16);
+				nonce[14] = (uint8_t)(block_num >> 8);
+				nonce[15] = (uint8_t)(block_num);
+			} else {
+				return TC_CRYPTO_FAIL;
+			}
+		}
+		/* update the output */
+		*out++ = buffer[i%(TC_AES_BLOCK_SIZE)] ^ *in++;
+	}
+
+	/* update the counter */
+	ctr[12] = nonce[12]; ctr[13] = nonce[13];
+	ctr[14] = nonce[14]; ctr[15] = nonce[15];
+
+	return TC_CRYPTO_SUCCESS;
+}