diff options
-rw-r--r-- | Makefile | 3 | ||||
-rw-r--r-- | README | 17 | ||||
-rw-r--r-- | luascrypt.c | 39 |
3 files changed, 51 insertions, 8 deletions
@@ -100,11 +100,10 @@ LIBCRYPT_C := lib/crypto/crypto_aesctr.c \ lib/crypto/crypto_scrypt-ref.c \ lib/crypto/sha256.c -CFLAGS ?= -O2 -Wall INSTALL := /usr/bin/install SCRYPT_LIBS := -lscrypt -CFLAGS := $(CFLAGS) -fPIC +override CFLAGS := $(CFLAGS) -O2 -Wall -fPIC all: lua-5.1-try lua-5.2-try @@ -6,11 +6,26 @@ verification library. lua-scrypt uses the [libscrypt][] library and provides a simple interface for hashing and verifying passwords. local scrypt = require "scrypt" - + local hash = scrypt.hash_password("Hello world") assert(scrypt.verify_password(hash, "Hello world")) +Installation +============ + +To compile lua-scrypt, on platforms with libscrypt 1.21 or later run, + + $ make CFLAGS+=-DTRUST_LIBSCRYPT_SALT_GEN + +for platforms with older versions (earlier than 1.21) of libscrypt run, + + $ make + +To install lua-scrypt, run, + + $ make install + Thanks ====== diff --git a/luascrypt.c b/luascrypt.c index 181f1e8..11ae799 100644 --- a/luascrypt.c +++ b/luascrypt.c @@ -26,7 +26,9 @@ static void luascrypt_salt_gen(char *salt, int saltlen) { int fd; - /* We'd go with libscrypt's implementation, but since libscrypt's salt + /* Following comment applies to libscrypt prior to 1.21: + * + * We'd go with libscrypt's implementation, but since libscrypt's salt * generation is time based, we cannot fully trust it to generate * unique salts so to improve our chances we assume we have urandom * and fall back to libscrypt's implementation if we don't. Since the @@ -34,11 +36,31 @@ luascrypt_salt_gen(char *salt, int saltlen) * if we can... */ libscrypt_salt_gen(salt, saltlen); - + fd = open("/dev/urandom", O_RDONLY); if (fd >= 0) { - read(fd, salt, saltlen); /* Ignore errors in these two calls */ - close(fd); /* Since we have our fallback. */ + size_t total = 0; + ssize_t n; + + while (total < saltlen) { + n = read(fd, salt + total, saltlen - total); + if (n == 0) { + break; + } + + if (n == -1) { + if (errno == EINTR) { + continue; /* just try again */ + } + + /* Ignore all other errors, since we have our fallback. */ + break; + } + + total += n; + } + + close(fd); } } @@ -70,8 +92,15 @@ luascrypt_hash_password(lua_State *L) return luaL_error(L, "Unable to generate password hash: %s", "N is too large (limited to 2^15)"); } - + +#ifdef TRUST_LIBSCRYPT_SALT_GEN + /* Modern versions of libscrypt generate sufficiently random salts + * and take a uint8_t * instead of char * + */ + libscrypt_salt_gen((uint8_t *) salt, sizeof(salt)); +#else luascrypt_salt_gen(salt, sizeof(salt)); +#endif if (libscrypt_scrypt((uint8_t*)passwd, passwd_len, (uint8_t*)salt, sizeof(salt), |