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authorKim Alvefur <zash@zash.se>2016-02-22 18:44:43 +0100
committerKim Alvefur <zash@zash.se>2016-02-22 18:44:43 +0100
commited8199402ff2a84e57f256818ebc2c505c2ac41d (patch)
tree212768ff3b1d64b64c32583515751108b54d7b31 /util-src
parent11ebf4f1dc56644712e12e451e9b37c472c69238 (diff)
downloadprosody-ed8199402ff2a84e57f256818ebc2c505c2ac41d.tar.gz
prosody-ed8199402ff2a84e57f256818ebc2c505c2ac41d.zip
util.crand: C binding to one of OpenSSL, Linux getrandom() or OpenBSD arc4random() CSPRNG
Diffstat (limited to 'util-src')
-rw-r--r--util-src/Makefile9
-rw-r--r--util-src/crand.c156
2 files changed, 164 insertions, 1 deletions
diff --git a/util-src/Makefile b/util-src/Makefile
index 85b190b9..9c6c377c 100644
--- a/util-src/Makefile
+++ b/util-src/Makefile
@@ -8,6 +8,10 @@ TARGET?=../util/
ALL=encodings.so hashes.so net.so pposix.so signal.so table.so ringbuffer.so
+ifdef RANDOM
+ALL+=crand.so
+endif
+
.PHONY: all install clean
.SUFFIXES: .c .o .so
@@ -17,11 +21,14 @@ install: $(ALL)
$(INSTALL_DATA) $^ $(TARGET)
clean:
- rm -f $(ALL)
+ rm -f $(ALL) $(patsubst %.so,%.o,$(ALL))
encodings.so: LDLIBS+=$(IDNA_LIBS)
hashes.so: LDLIBS+=$(OPENSSL_LIBS)
+crand.o: CFLAGS+=-DWITH_$(RANDOM)
+crand.so: LDLIBS+=$(RANDOM_LIBS)
+
%.so: %.o
$(LD) $(LDFLAGS) -o $@ $^ $(LDLIBS)
diff --git a/util-src/crand.c b/util-src/crand.c
new file mode 100644
index 00000000..9a45f10f
--- /dev/null
+++ b/util-src/crand.c
@@ -0,0 +1,156 @@
+/* Prosody IM
+-- Copyright (C) 2008-2016 Matthew Wild
+-- Copyright (C) 2008-2016 Waqas Hussain
+-- Copyright (C) 2016 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+*/
+
+/*
+* crand.c
+* C PRNG interface
+*/
+
+#include "lualib.h"
+#include "lauxlib.h"
+
+#include <string.h>
+#include <errno.h>
+
+/*
+ * TODO: Decide on fixed size or dynamically allocated buffer
+ */
+#if 1
+#include <malloc.h>
+#else
+#define BUFLEN 256
+#endif
+
+#if defined(WITH_GETRANDOM)
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <linux/random.h>
+
+#ifndef SYS_getrandom
+#error getrandom() requires Linux 3.17 or later
+#endif
+
+/* Was this not supposed to be a function? */
+int getrandom(char *buf, size_t len, int flags) {
+ return syscall(SYS_getrandom, buf, len, flags);
+}
+
+#elif defined(WITH_ARC4RANDOM)
+#include <stdlib.h>
+#elif defined(WITH_OPENSSL)
+#include <openssl/rand.h>
+#else
+#error util.crand compiled without a random source
+#endif
+
+int Lrandom(lua_State *L) {
+#ifdef BUFLEN
+ unsigned char buf[BUFLEN];
+#else
+ unsigned char *buf;
+#endif
+ int ret = 0;
+ size_t len = (size_t)luaL_checkint(L, 1);
+#ifdef BUFLEN
+ len = len > BUFLEN ? BUFLEN : len;
+#else
+ buf = malloc(len);
+
+ if(buf == NULL) {
+ lua_pushnil(L);
+ lua_pushstring(L, "out of memory");
+ /* or it migth be better to
+ * return lua_error(L);
+ */
+ return 2;
+ }
+#endif
+
+#if defined(WITH_GETRANDOM)
+ ret = getrandom(buf, len, 0);
+
+ if(ret < 0) {
+#ifndef BUFLEN
+ free(buf);
+#endif
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ lua_pushinteger(L, errno);
+ return 3;
+ }
+
+#elif defined(WITH_ARC4RANDOM)
+ arc4random_buf(buf, len);
+ ret = len;
+#elif defined(WITH_OPENSSL)
+ ret = RAND_bytes(buf, len);
+
+ if(ret == 1) {
+ ret = len;
+ } else {
+#ifndef BUFLEN
+ free(buf);
+#endif
+ lua_pushnil(L);
+ lua_pushstring(L, "failed");
+ /* lua_pushinteger(L, ERR_get_error()); */
+ return 2;
+ }
+
+#endif
+
+ lua_pushlstring(L, buf, ret);
+#ifndef BUFLEN
+ free(buf);
+#endif
+ return 1;
+}
+
+#ifdef ENABLE_SEEDING
+int Lseed(lua_State *L) {
+ size_t len;
+ const char *seed = lua_tolstring(L, 1, &len);
+
+#if defined(WITH_OPENSSL)
+ RAND_add(seed, len, len);
+ return 0;
+#else
+ lua_pushnil(L);
+ lua_pushliteral(L, "not-supported");
+ return 2;
+#endif
+}
+#endif
+
+int luaopen_util_crand(lua_State *L) {
+ lua_newtable(L);
+ lua_pushcfunction(L, Lrandom);
+ lua_setfield(L, -2, "bytes");
+#ifdef ENABLE_SEEDING
+ lua_pushcfunction(L, Lseed);
+ lua_setfield(L, -2, "seed");
+#endif
+
+#if defined(WITH_GETRANDOM)
+ lua_pushstring(L, "Linux");
+#elif defined(WITH_ARC4RANDOM)
+ lua_pushstring(L, "arc4random()");
+#elif defined(WITH_OPENSSL)
+ lua_pushstring(L, "OpenSSL");
+#endif
+ lua_setfield(L, -2, "_source");
+
+#if defined(WITH_OPENSSL) && defined(_WIN32)
+ /* Do we need to seed this on Windows? */
+#endif
+
+ return 1;
+}
+