Improve broker generated client ids for the non-Linux case.

Removes libuuid dependency.

ChangeLog.txt

@@ -1,6 +1,10 @@
 1.6 - 2018xxxx
 ==============
 
+Broker features:
+- Improved general support for broker generated client ids. Removed libuuid
+  dependency.
+
 Client library features:
 - Add mosquitto_subscribe_multiple() for sending subscriptions to multiple
   topics in one command.

compiling.txt

@@ -3,7 +3,6 @@ are optional.
 
 * openssl
 * c-ares (for DNS-SRV support, disabled by default)
-* libuuid (from util-linux, can be disabled)
 * tcp-wrappers (optional, package name libwrap0-dev)
 * libwebsockets (optional, disabled by default, version 1.3 and above)
 * On Windows, a pthreads library is required if threading support is to be

config.mk

@@ -64,10 +64,6 @@ WITH_SYSTEMD:=no
 # Build with SRV lookup support.
 WITH_SRV:=no
 
-# Build using libuuid for clientid generation (Linux only - please report if
-# supported on your platform).
-WITH_UUID:=yes
-
 # Build with websockets support on the broker.
 WITH_WEBSOCKETS:=no
 
@@ -209,13 +205,6 @@ ifeq ($(WITH_SOCKS),yes)
 	CLIENT_CFLAGS:=$(CLIENT_CFLAGS) -DWITH_SOCKS
 endif
 
-ifeq ($(WITH_UUID),yes)
-	ifeq ($(UNAME),Linux)
-		BROKER_CFLAGS:=$(BROKER_CFLAGS) -DWITH_UUID
-		BROKER_LIBS:=$(BROKER_LIBS) -luuid
-	endif
-endif
-
 ifeq ($(WITH_BRIDGE),yes)
 	BROKER_CFLAGS:=$(BROKER_CFLAGS) -DWITH_BRIDGE
 endif

readme.md

@@ -66,7 +66,6 @@ already be built. Use `make binary` to skip building the man pages, or install
 ### Build Dependencies
 
 * c-ares (libc-ares-dev on Debian based systems) - disable with `make WITH_SRV=no`
-* libuuid (uuid-dev) - disable with `make WITH_UUID=no`
 * libwebsockets (libwebsockets-dev) - enable with `make WITH_WEBSOCKETS=yes`
 * openssl (libssl-dev on Debian based systems) - disable with `make WITH_TLS=no`
 * xsltproc (xsltproc and docbook-xsl on Debian based systems) - only needed when building from git sources - disable with `make WITH_DOCS=no`

snap/snapcraft.yaml

@@ -51,14 +51,12 @@ parts:
 
     build-packages:
       - libssl-dev
-      - uuid-dev
       - xsltproc
       - docbook-xsl
       - gcc
       - g++
     stage-packages:
       - libssl1.0.0
-      - libuuid1
     prime:
       - usr/sbin/mosquitto
       - usr/bin/mosquitto_pub
@@ -66,7 +64,6 @@ parts:
       - usr/lib/libmosquitto.so*
       - lib/*-linux-gnu/libcrypto.so*
       - lib/*-linux-gnu/libssl.so*
-      - lib/*-linux-gnu/libuuid.so*
 
   lws:
     plugin: cmake

src/CMakeLists.txt

@@ -160,15 +160,6 @@ if (${WITH_WEBSOCKETS} STREQUAL ON)
 	endif (${STATIC_WEBSOCKETS} STREQUAL ON)
 endif (${WITH_WEBSOCKETS} STREQUAL ON)
 
-# Simple detect libuuid
-if(NOT APPLE)
-	FIND_PATH(UUID_HEADER uuid/uuid.h)
-	if (UUID_HEADER)
-		add_definitions(-DWITH_UUID)
-		set (MOSQ_LIBS ${MOSQ_LIBS} uuid)
-	endif (UUID_HEADER)
-endif(NOT APPLE)
-
 add_executable(mosquitto ${MOSQ_SRCS})
 target_link_libraries(mosquitto ${MOSQ_LIBS})
 

src/handle_connect.c

@@ -30,28 +30,75 @@ Contributors:
 #include "tls_mosq.h"
 #include "util_mosq.h"
 
-#ifdef WITH_UUID
-#  include <uuid/uuid.h>
+#ifdef WITH_TLS
+#  include <openssl/rand.h>
+#endif
+
+#ifdef __linux__
+#  include <sys/random.h>
 #endif
 
 #ifdef WITH_WEBSOCKETS
 #  include <libwebsockets.h>
 #endif
 
+
+static int random_16_bytes(uint8_t *bytes)
+{
+	int rc = MOSQ_ERR_UNKNOWN;
+
+#ifdef WITH_TLS
+	if(RAND_bytes(bytes, 16) == 1){
+		rc = MOSQ_ERR_SUCCESS;
+	}
+#else
+#  ifdef __GLIBC__
+	if(getrandom(bytes, 16, 0) == 0){
+		rc = MOSQ_ERR_SUCCESS;
+	}
+#  elif defined(WIN32)
+	HRYPTPROV provider;
+
+	if(!CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)){
+		return MOSQ_ERR_UNKNOWN;
+	}
+
+	if(CryptGenRandom(provider, 16, bytes)){
+		rc = MOSQ_ERR_SUCCESS;
+	}
+
+	CryptReleaseContext(provider, 0);
+#  else
+	int i;
+
+	for(i=0; i<16; i++){
+		bytes[i] = (uint8_t )(random()&0xFF);
+	}
+	rc = MOSQ_ERR_SUCCESS;
+#  endif
+#endif
+	return rc;
+}
+
+static char nibble_to_hex(uint8_t value)
+{
+	if(value < 0x0A){
+		return '0'+value;
+	}else{
+		return 'A'+value-0x0A;
+	}
+}
+
 static char *client_id_gen(struct mosquitto_db *db, int *idlen, const char *auto_id_prefix, int auto_id_prefix_len)
 {
 	char *client_id;
-#ifdef WITH_UUID
-	uuid_t uuid;
-#else
+	uint8_t rnd[16];
 	int i;
-#endif
+	int pos;
+
+	if(random_16_bytes(rnd)) return NULL;
 
-#ifdef WITH_UUID
 	*idlen = 36 + auto_id_prefix_len;
-#else
-	*idlen = 64 + auto_id_prefix_len;
-#endif
 
 	client_id = (char *)mosquitto__calloc((*idlen) + 1, sizeof(char));
 	if(!client_id){
@@ -61,16 +108,17 @@ static char *client_id_gen(struct mosquitto_db *db, int *idlen, const char *auto
 		memcpy(client_id, auto_id_prefix, auto_id_prefix_len);
 	}
 
-
-#ifdef WITH_UUID
-	uuid_generate_random(uuid);
-	uuid_unparse_lower(uuid, &client_id[auto_id_prefix_len]);
-#else
-	for(i=0; i<64; i++){
-		client_id[i+auto_id_prefix_len] = (rand()%73)+48;
+	pos = 0;
+	for(i=0; i<16; i++){
+		client_id[auto_id_prefix_len + pos + 0] = nibble_to_hex(rnd[i] & 0x0F);
+		client_id[auto_id_prefix_len + pos + 1] = nibble_to_hex((rnd[i] >> 4) & 0x0F);
+		pos += 2;
+		if(pos == 8 || pos == 13 || pos == 18 || pos == 23){
+			client_id[auto_id_prefix_len + pos] = '-';
+			pos++;
+		}
 	}
-	client_id[i] = '\0';
-#endif
+
 	return client_id;
 }
 

travis-install.sh

@@ -3,7 +3,7 @@
 
 if [ "$TRAVIS_OS_NAME" == "linux" ]; then
 	sudo apt-get update -qq
-	sudo apt-get install -y debhelper libc-ares-dev libssl-dev libwrap0-dev python-all python3-all uthash-dev uuid-dev libuuid1 xsltproc docbook-xsl libcunit1-dev
+	sudo apt-get install -y debhelper libc-ares-dev libssl-dev libwrap0-dev python-all python3-all uthash-dev xsltproc docbook-xsl libcunit1-dev
 fi
 
 if [ "$TRAVIS_OS_NAME" == "osx" ]; then