X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_key.c;h=0890755e57db2ccf6aa54d500670fe5e8558140c;hb=d93d4f9dbd09bc5e53a9b5eeb1cc94939fee32bc;hp=a957780b3633dfbef6d51748745dad8795520298;hpb=3a149f7521dfff67e6a790c1a830afc649ae083e;p=tinc

diff --git a/src/protocol_key.c b/src/protocol_key.c
index a957780b..0890755e 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -32,10 +32,12 @@
 #include "sptps.h"
 #include "utils.h"
 #include "compression.h"
+#include "random.h"
+#include "xalloc.h"
 
 void send_key_changed(void) {
 #ifndef DISABLE_LEGACY
-	send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+	send_request(everyone, "%d %x %s", KEY_CHANGED, prng(UINT32_MAX), myself->name);
 
 	/* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
 
@@ -102,9 +104,9 @@ static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data
 	(void)type;
 	node_t *to = handle;
 	to->sptps.send_data = send_sptps_data_myself;
-	char buf[len * 4 / 3 + 5];
 
-	b64encode(data, buf, len);
+	char *buf = alloca(B64_SIZE(len));
+	b64encode_tinc(data, buf, len);
 
 	return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_KEY, buf);
 }
@@ -117,14 +119,16 @@ bool send_req_key(node_t *to) {
 			return true;
 		}
 
-		char label[25 + strlen(myself->name) + strlen(to->name)];
-		snprintf(label, sizeof(label), "tinc UDP key expansion %s %s", myself->name, to->name);
+		const size_t labellen = 25 + strlen(myself->name) + strlen(to->name);
+		char *label = alloca(labellen);
+		snprintf(label, labellen, "tinc UDP key expansion %s %s", myself->name, to->name);
+
 		sptps_stop(&to->sptps);
 		to->status.validkey = false;
 		to->status.waitingforkey = true;
 		to->last_req_key = now.tv_sec;
 		to->incompression = myself->incompression;
-		return sptps_start(&to->sptps, to, true, true, myself->connection->ecdsa, to->ecdsa, label, sizeof(label), send_initial_sptps_data, receive_sptps_record);
+		return sptps_start(&to->sptps, to, true, true, myself->connection->ecdsa, to->ecdsa, label, labellen, send_initial_sptps_data, receive_sptps_record);
 	}
 
 	return send_request(to->nexthop->connection, "%d %s %s", REQ_KEY, myself->name, to->name);
@@ -148,7 +152,7 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, no
 		char buf[MAX_STRING_SIZE];
 		size_t len;
 
-		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) {
+		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode_tinc(buf, buf, strlen(buf)))) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s) to %s (%s): %s", "SPTPS_PACKET", from->name, from->hostname, to->name, to->hostname, "invalid SPTPS data");
 			return true;
 		}
@@ -233,18 +237,19 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, no
 		char buf[MAX_STRING_SIZE];
 		size_t len;
 
-		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) {
+		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode_tinc(buf, buf, strlen(buf)))) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_SPTPS_START", from->name, from->hostname, "invalid SPTPS data");
 			return true;
 		}
 
-		char label[25 + strlen(from->name) + strlen(myself->name)];
-		snprintf(label, sizeof(label), "tinc UDP key expansion %s %s", from->name, myself->name);
+		const size_t labellen = 25 + strlen(from->name) + strlen(myself->name);
+		char *label = alloca(labellen);
+		snprintf(label, labellen, "tinc UDP key expansion %s %s", from->name, myself->name);
 		sptps_stop(&from->sptps);
 		from->status.validkey = false;
 		from->status.waitingforkey = true;
 		from->last_req_key = now.tv_sec;
-		sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof(label), send_sptps_data_myself, receive_sptps_record);
+		sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, labellen, send_sptps_data_myself, receive_sptps_record);
 		sptps_receive_data(&from->sptps, buf, len);
 		send_mtu_info(myself, from, MTU);
 		return true;
@@ -336,17 +341,21 @@ bool send_ans_key(node_t *to) {
 	return false;
 #else
 	size_t keylen = myself->incipher ? cipher_keylength(myself->incipher) : 1;
-	char key[keylen * 2 + 1];
+	size_t keyhexlen = HEX_SIZE(keylen);
+	char *key = alloca(keyhexlen);
 
 	randomize(key, keylen);
 
-	cipher_close(to->incipher);
-	digest_close(to->indigest);
+	cipher_free(to->incipher);
+	to->incipher = NULL;
+
+	digest_free(to->indigest);
+	to->indigest = NULL;
 
 	if(myself->incipher) {
-		to->incipher = cipher_open_by_nid(cipher_get_nid(myself->incipher));
+		to->incipher = cipher_alloc();
 
-		if(!to->incipher) {
+		if(!cipher_open_by_nid(to->incipher, cipher_get_nid(myself->incipher))) {
 			abort();
 		}
 
@@ -356,10 +365,11 @@ bool send_ans_key(node_t *to) {
 	}
 
 	if(myself->indigest) {
-		to->indigest = digest_open_by_nid(digest_get_nid(myself->indigest),
-		                                  digest_length(myself->indigest));
+		to->indigest = digest_alloc();
 
-		if(!to->indigest) {
+		if(!digest_open_by_nid(to->indigest,
+		                       digest_get_nid(myself->indigest),
+		                       digest_length(myself->indigest))) {
 			abort();
 		}
 
@@ -382,12 +392,16 @@ bool send_ans_key(node_t *to) {
 
 	to->status.validkey_in = true;
 
-	return send_request(to->nexthop->connection, "%d %s %s %s %d %d %zu %d", ANS_KEY,
-	                    myself->name, to->name, key,
-	                    cipher_get_nid(to->incipher),
-	                    digest_get_nid(to->indigest),
-	                    digest_length(to->indigest),
-	                    to->incompression);
+	bool sent = send_request(to->nexthop->connection, "%d %s %s %s %d %d %lu %d", ANS_KEY,
+	                         myself->name, to->name, key,
+	                         cipher_get_nid(to->incipher),
+	                         digest_get_nid(to->indigest),
+	                         (unsigned long)digest_length(to->indigest),
+	                         to->incompression);
+
+	memzero(key, keyhexlen);
+
+	return sent;
 #endif
 }
 
@@ -398,11 +412,11 @@ bool ans_key_h(connection_t *c, const char *request) {
 	char address[MAX_STRING_SIZE] = "";
 	char port[MAX_STRING_SIZE] = "";
 	int cipher, digest;
-	size_t maclength;
+	unsigned long maclength;
 	int compression;
 	node_t *from, *to;
 
-	if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %zu %d "MAX_STRING" "MAX_STRING,
+	if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %lu %d "MAX_STRING" "MAX_STRING,
 	                from_name, to_name, key, &cipher, &digest, &maclength,
 	                &compression, address, port) < 7) {
 		logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
@@ -459,8 +473,11 @@ bool ans_key_h(connection_t *c, const char *request) {
 
 #ifndef DISABLE_LEGACY
 	/* Don't use key material until every check has passed. */
-	cipher_close(from->outcipher);
-	digest_close(from->outdigest);
+	cipher_free(from->outcipher);
+	from->outcipher = NULL;
+
+	digest_free(from->outdigest);
+	from->outdigest = NULL;
 #endif
 
 	if(!from->status.sptps) {
@@ -518,8 +535,9 @@ bool ans_key_h(connection_t *c, const char *request) {
 	/* SPTPS or old-style key exchange? */
 
 	if(from->status.sptps) {
-		uint8_t buf[strlen(key)];
-		size_t len = b64decode(key, buf, strlen(key));
+		const size_t buflen = strlen(key);
+		uint8_t *buf = alloca(buflen);
+		size_t len = b64decode_tinc(key, buf, buflen);
 
 		if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
 			/* Uh-oh. It might be that the tunnel is stuck in some corrupted state,
@@ -555,7 +573,11 @@ bool ans_key_h(connection_t *c, const char *request) {
 	/* Check and lookup cipher and digest algorithms */
 
 	if(cipher) {
-		if(!(from->outcipher = cipher_open_by_nid(cipher))) {
+		from->outcipher = cipher_alloc();
+
+		if(!cipher_open_by_nid(from->outcipher, cipher)) {
+			cipher_free(from->outcipher);
+			from->outcipher = NULL;
 			logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
 			return false;
 		}
@@ -564,7 +586,11 @@ bool ans_key_h(connection_t *c, const char *request) {
 	}
 
 	if(digest) {
-		if(!(from->outdigest = digest_open_by_nid(digest, maclength))) {
+		from->outdigest = digest_alloc();
+
+		if(!digest_open_by_nid(from->outdigest, digest, maclength)) {
+			digest_free(from->outdigest);
+			from->outdigest = NULL;
 			logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
 			return false;
 		}