Software /
code /
prosody
File
util-src/crand.c @ 12047:81858fd6f198
mod_smacks: Flag both sessions to prevent duplicating queue on resumption
I have no idea what is going on in this code, which session is which?
Something has one of the sessions as an upvalue which is where the
filter checks for it.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Tue, 14 Dec 2021 12:59:38 +0100 |
parent | 8451:770f79a9635c |
child | 12470:80f3123053e2 |
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/* Prosody IM -- Copyright (C) 2008-2017 Matthew Wild -- Copyright (C) 2008-2017 Waqas Hussain -- Copyright (C) 2016-2017 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 * * The purpose of this module is to provide access to a PRNG in * environments without /dev/urandom * * Caution! This has not been extensively tested. * */ #define _DEFAULT_SOURCE #include <stdlib.h> #include <string.h> #include <errno.h> #include "lualib.h" #include "lauxlib.h" #if defined(WITH_GETRANDOM) #ifndef __GLIBC_PREREQ /* Not compiled with glibc at all */ #define __GLIBC_PREREQ(a,b) 0 #endif #if ! __GLIBC_PREREQ(2,25) /* Not compiled with a glibc that provides getrandom() */ #include <unistd.h> #include <sys/syscall.h> #ifndef SYS_getrandom #error getrandom() requires Linux 3.17 or later #endif /* This wasn't present before glibc 2.25 */ int getrandom(void *buf, size_t buflen, unsigned int flags) { return syscall(SYS_getrandom, buf, buflen, flags); } #else #include <sys/random.h> #endif #elif defined(WITH_OPENSSL) #include <openssl/rand.h> #elif defined(WITH_ARC4RANDOM) #ifdef __linux__ #include <bsd/stdlib.h> #endif #else #error util.crand compiled without a random source #endif #ifndef SMALLBUFSIZ #define SMALLBUFSIZ 32 #endif int Lrandom(lua_State *L) { char smallbuf[SMALLBUFSIZ]; char *buf = &smallbuf[0]; const lua_Integer l = luaL_checkinteger(L, 1); const size_t len = l; luaL_argcheck(L, l >= 0, 1, "must be > 0"); if(len == 0) { lua_pushliteral(L, ""); return 1; } if(len > SMALLBUFSIZ) { buf = lua_newuserdata(L, len); } #if defined(WITH_GETRANDOM) /* * This acts like a read from /dev/urandom with the exception that it * *does* block if the entropy pool is not yet initialized. */ int left = len; char *p = buf; do { int ret = getrandom(p, left, 0); if(ret < 0) { lua_pushstring(L, strerror(errno)); return lua_error(L); } p += ret; left -= ret; } while(left > 0); #elif defined(WITH_ARC4RANDOM) arc4random_buf(buf, len); #elif defined(WITH_OPENSSL) if(!RAND_status()) { lua_pushliteral(L, "OpenSSL PRNG not seeded"); return lua_error(L); } if(RAND_bytes((unsigned char *)buf, len) != 1) { /* TODO ERR_get_error() */ lua_pushstring(L, "RAND_bytes() failed"); return lua_error(L); } #endif lua_pushlstring(L, buf, len); return 1; } int luaopen_util_crand(lua_State *L) { #if (LUA_VERSION_NUM > 501) luaL_checkversion(L); #endif lua_createtable(L, 0, 2); lua_pushcfunction(L, Lrandom); lua_setfield(L, -2, "bytes"); #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"); return 1; }