From 57fea029cc3d6faf5a8b9ad4b17b543359fe7ccb Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 20 Apr 2022 15:40:40 +0200 Subject: seedrng: compress format strings with %s arguments - Avoid an xstrdup call with seed_dir. - Compress format strings with %s arguments. - Open /dev/urandom for add entropy ioctl rather than /dev/random, so that /dev/random is only used for the already-sightly-flawed poll() check for creditability. function old new delta seedrng_main 948 958 +10 seed_from_file_if_exists 410 417 +7 .rodata 108338 108206 -132 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/1 up/down: 17/-132) Total: -115 bytes text data bss dec hex filename 975829 4227 1816 981872 efb70 busybox_old 975714 4227 1816 981757 efafd busybox_unstripped Signed-off-by: Jason A. Donenfeld Signed-off-by: Bernhard Reutner-Fischer --- util-linux/seedrng.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) (limited to 'util-linux') diff --git a/util-linux/seedrng.c b/util-linux/seedrng.c index 5735dc059..5a41addf0 100644 --- a/util-linux/seedrng.c +++ b/util-linux/seedrng.c @@ -129,7 +129,7 @@ static int seed_rng(uint8_t *seed, size_t len, bool credit) } memcpy(req.buffer, seed, len); - random_fd = open("/dev/random", O_RDONLY); + random_fd = open("/dev/urandom", O_RDONLY); if (random_fd < 0) return -1; ret = ioctl(random_fd, RNDADDENTROPY, &req); @@ -150,11 +150,11 @@ static int seed_from_file_if_exists(const char *filename, int dfd, bool credit, if (seed_len < 0) { if (errno == ENOENT) return 0; - bb_simple_perror_msg("unable to read seed file"); + bb_perror_msg("unable to%s seed", " read"); return -1; } if ((unlink(filename) < 0 || fsync(dfd) < 0) && seed_len) { - bb_simple_perror_msg("unable to remove seed, so not seeding"); + bb_perror_msg("unable to%s seed", " remove"); return -1; } else if (!seed_len) return 0; @@ -164,7 +164,7 @@ static int seed_from_file_if_exists(const char *filename, int dfd, bool credit, printf("Seeding %zd bits %s crediting\n", seed_len * 8, credit ? "and" : "without"); if (seed_rng(seed, seed_len, credit) < 0) { - bb_simple_perror_msg("unable to seed"); + bb_perror_msg("unable to%s seed", ""); return -1; } return 0; @@ -173,7 +173,7 @@ static int seed_from_file_if_exists(const char *filename, int dfd, bool credit, int seedrng_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE; int seedrng_main(int argc UNUSED_PARAM, char *argv[]) { - char *seed_dir, *creditable_seed, *non_creditable_seed; + const char *seed_dir = DEFAULT_SEED_DIR, *creditable_seed, *non_creditable_seed; int ret, fd = -1, dfd = -1, program_ret = 0; uint8_t new_seed[MAX_SEED_LEN]; size_t new_seed_len; @@ -195,8 +195,6 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) #endif opt = getopt32long(argv, "d:n", longopts, &seed_dir); - if (!(opt & OPT_d) || !seed_dir) - seed_dir = xstrdup(DEFAULT_SEED_DIR); skip_credit = opt & OPT_n; creditable_seed = concat_path_file(seed_dir, CREDITABLE_SEED_NAME); non_creditable_seed = concat_path_file(seed_dir, NON_CREDITABLE_SEED_NAME); @@ -206,11 +204,11 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) bb_simple_error_msg_and_die(bb_msg_you_must_be_root); if (mkdir(seed_dir, 0700) < 0 && errno != EEXIST) - bb_simple_perror_msg_and_die("unable to create seed directory"); + bb_perror_msg_and_die("unable to %s seed directory", "create"); dfd = open(seed_dir, O_DIRECTORY | O_RDONLY); if (dfd < 0 || flock(dfd, LOCK_EX) < 0) { - bb_simple_perror_msg("unable to lock seed directory"); + bb_perror_msg("unable to %s seed directory", "lock"); program_ret = 1; goto out; } @@ -232,7 +230,7 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) new_seed_len = determine_optimal_seed_len(); ret = read_new_seed(new_seed, new_seed_len, &new_seed_creditable); if (ret < 0) { - bb_simple_perror_msg("unable to read new seed"); + bb_perror_msg("unable to%s seed", " read new"); new_seed_len = SHA256_OUTSIZE; memset(new_seed, 0, SHA256_OUTSIZE); program_ret |= 1 << 3; @@ -241,10 +239,10 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) sha256_hash(&hash, new_seed, new_seed_len); sha256_end(&hash, new_seed + new_seed_len - SHA256_OUTSIZE); - printf("Saving %zu bits of %s seed for next boot\n", new_seed_len * 8, new_seed_creditable ? "creditable" : "non-creditable"); + printf("Saving %zu bits of %screditable seed for next boot\n", new_seed_len * 8, new_seed_creditable ? "" : "non-"); fd = open(non_creditable_seed, O_WRONLY | O_CREAT | O_TRUNC, 0400); if (fd < 0 || full_write(fd, new_seed, new_seed_len) != (ssize_t)new_seed_len || fsync(fd) < 0) { - bb_simple_perror_msg("unable to write seed file"); + bb_perror_msg("unable to%s seed", " write"); program_ret |= 1 << 4; goto out; } -- cgit v1.2.3