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c8ba23bce

Denys Vlasenko

2017-01-18

SUCCESS Duration: 190s

Subject

tls: massage writing for encryption support; finer-grained debug

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

networking/tls.c +38 -31

networking/tls.c+38 -31

@@ -25,7 +25,9 @@

	#include "tls.h"

-	#define TLS_DEBUG 2
+	#define TLS_DEBUG 1
+	#define TLS_DEBUG_HASH 0
+	#define TLS_DEBUG_DER 0

	#if TLS_DEBUG
	# define dbg(...) fprintf(stderr, __VA_ARGS__)
@@ -33,6 +35,12 @@
	# define dbg(...) ((void)0)
	#endif

+	#if TLS_DEBUG_DER
+	# define dbg_der(...) fprintf(stderr, __VA_ARGS__)
+	#else
+	# define dbg_der(...) ((void)0)
+	#endif
+
	#define RECORD_TYPE_CHANGE_CIPHER_SPEC 20
	#define RECORD_TYPE_ALERT 21
	#define RECORD_TYPE_HANDSHAKE 22
@@ -269,7 +277,7 @@ static void sha256_peek(sha256_ctx_t ctx, void buffer)
	sha256_end(&ctx_copy, buffer);
	}

-	#if TLS_DEBUG >= 2
+	#if TLS_DEBUG_HASH
	static void sha256_hash_dbg(const char fmt, sha256_ctx_t ctx, const void *buffer, size_t len)
	{
	uint8_t h[SHA256_OUTSIZE];
@@ -283,7 +291,7 @@ static void sha256_hash_dbg(const char fmt, sha256_ctx_t ctx, const void *buff
	#else
	# define sha256_hash_dbg(fmt, ctx, buffer, len) \
	sha256_hash(ctx, buffer, len)
-	#endif /* not TLS_DEBUG >= 2 */
+	#endif

	// RFC 2104
	// HMAC(key, text) based on a hash H (say, sha256) is:
@@ -424,8 +432,7 @@ static void prf_hmac_sha256(
	#undef SEED
	}

-	static
-	tls_state_t *new_tls_state(void)
+	static tls_state_t *new_tls_state(void)
	{
	tls_state_t tls = xzalloc(sizeof(tls));
	tls->fd = -1;
@@ -488,31 +495,31 @@ static void xwrite_and_hash(tls_state_t tls, /const/ void buf, unsigned size
	uint8_t mac_hash[SHA256_OUTSIZE];
	struct record_hdr *xhdr = buf;

-	if (tls->encrypt_on_write) {
+	if (!tls->encrypt_on_write) {
+	xwrite(tls->fd, buf, size);
+	dbg("wrote %u bytes\n", size);
+	/* Handshake hash does not include record headers */
+	if (size > 5 && xhdr->type == RECORD_TYPE_HANDSHAKE) {
+	sha256_hash_dbg(">> sha256:%s", &tls->handshake_sha256_ctx, (uint8_t*)buf + 5, size - 5);
+	}
+	return;
+	}
+
	//TODO: convert hmac_sha256 to precomputed
-	hmac_sha256(mac_hash,
+	hmac_sha256(mac_hash,
	tls->client_write_MAC_key, sizeof(tls->client_write_MAC_key),
	&tls->write_seq64_be, sizeof(tls->write_seq64_be),
	buf, size,
-	NULL);
-	tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
-	/* Temporarily change for writing */
-	xhdr->len16_lo += SHA256_OUTSIZE;
-	}
+	NULL);
+	tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));

+	xhdr->len16_lo += SHA256_OUTSIZE;
	xwrite(tls->fd, buf, size);
+	xhdr->len16_lo -= SHA256_OUTSIZE;
	dbg("wrote %u bytes\n", size);

-	if (tls->encrypt_on_write) {
-	xwrite(tls->fd, mac_hash, sizeof(mac_hash));
-	dbg("wrote %u bytes of hash\n", (int)sizeof(mac_hash));
-	xhdr->len16_lo -= SHA256_OUTSIZE;
-	}
-
-	/* Handshake hash does not include record headers */
-	if (size > 5 && xhdr->type == RECORD_TYPE_HANDSHAKE) {
-	sha256_hash_dbg(">> sha256:%s", &tls->handshake_sha256_ctx, (uint8_t*)buf + 5, size - 5);
-	}
+	xwrite(tls->fd, mac_hash, sizeof(mac_hash));
+	dbg("wrote %u bytes of hash\n", (int)sizeof(mac_hash));
	}

	static int xread_tls_block(tls_state_t *tls)
@@ -611,7 +618,7 @@ static uint8_t enter_der_item(uint8_t der, uint8_t **endp)
	{
	uint8_t *new_der;
	unsigned len = get_der_len(&new_der, der, *endp);
-	dbg("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
+	dbg_der("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
	/* Move "end" position to cover only this item */
	*endp = new_der + len;
	return new_der;
@@ -623,7 +630,7 @@ static uint8_t skip_der_item(uint8_t der, uint8_t *end)
	unsigned len = get_der_len(&new_der, der, end);
	/* Skip body */
	new_der += len;
-	dbg("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
+	dbg_der("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
	return new_der;
	}

@@ -632,7 +639,7 @@ static void der_binary_to_pstm(pstm_int pstm_n, uint8_t der, uint8_t *end)
	uint8_t *bin_ptr;
	unsigned len = get_der_len(&bin_ptr, der, end);

-	dbg("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
+	dbg_der("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
	pstm_init_for_read_unsigned_bin(/pool:/ NULL, pstm_n, len);
	pstm_read_unsigned_bin(pstm_n, bin_ptr, len);
	//return bin + len;
@@ -854,7 +861,7 @@ static void send_client_hello(tls_state_t *tls)
	/* record.comprtypes[0] = 0; */

	//dbg (make it repeatable): memset(record.rand32, 0x11, sizeof(record.rand32));
-	dbg(">> HANDSHAKE_CLIENT_HELLO\n");
+	dbg(">> CLIENT_HELLO\n");
	xwrite_and_hash(tls, &record, sizeof(record));
	memcpy(tls->client_and_server_rand32, record.rand32, sizeof(record.rand32));
	}
@@ -988,7 +995,7 @@ static void send_client_key_exchange(tls_state_t *tls)
	record.xhdr.len16_hi = len >> 8;
	record.xhdr.len16_lo = len & 0xff;

-	dbg(">> HANDSHAKE_CLIENT_KEY_EXCHANGE\n");
+	dbg(">> CLIENT_KEY_EXCHANGE\n");
	xwrite_and_hash(tls, &record, sizeof(record.xhdr) + len);

	// RFC 5246
@@ -1114,13 +1121,13 @@ static void send_change_cipher_spec(tls_state_t *tls)
	// includes all existing cipher suites.
	static void send_client_finished(tls_state_t *tls)
	{
-	struct client_finished {
+	struct finished {
	struct record_hdr xhdr;
	uint8_t type;
	uint8_t len24_hi, len24_mid, len24_lo;
	uint8_t prf_result[12];
	};
-	struct client_finished record;
+	struct finished record;
	uint8_t handshake_hash[SHA256_OUTSIZE];

	fill_handshake_record_hdr(&record.xhdr, sizeof(record));
@@ -1134,13 +1141,13 @@ static void send_client_finished(tls_state_t *tls)
	);
	dump_hex("from secret: %s\n", tls->master_secret, sizeof(tls->master_secret));
	dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1);
-	dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
+	dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
	dump_hex("=> digest: %s\n", record.prf_result, sizeof(record.prf_result));

	//(1) TODO: well, this should be encrypted on send, really.
	//(2) do we really need to also hash it?

-	dbg(">> HANDSHAKE_FINISHED\n");
+	dbg(">> FINISHED\n");
	xwrite_and_hash(tls, &record, sizeof(record));
	}