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398bb3861

Jason A. Donenfeld
Jason A. Donenfeld
2022-04-20
SUCCESS Duration: 153s

Subject

seedrng: further reduce size

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

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Commit Diff GitHub →

util-linux/seedrng.c +22 -55
util-linux/seedrng.c+22 -55
@@ -21,7 +21,7 @@
*/
//config:config SEEDRNG
-//config: bool "seedrng (2.4 kb)"
+//config: bool "seedrng (2.1 kb)"
//config: default y
//config: help
//config: Seed the kernel RNG from seed files, meant to be called
@@ -33,12 +33,11 @@
//kbuild:lib-$(CONFIG_SEEDRNG) += seedrng.o
//usage:#define seedrng_trivial_usage
-//usage: "[-d SEED_DIRECTORY] [-l LOCK_FILE] [-n]"
+//usage: "[-d SEED_DIRECTORY] [-n]"
//usage:#define seedrng_full_usage "\n\n"
//usage: "Seed the kernel RNG from seed files."
//usage: "\n"
//usage: "\n -d, --seed-dir DIR Use seed files from specified directory (default: /var/lib/seedrng)"
-//usage: "\n -l, --lock-file FILE Use file as exclusive lock (default: /var/run/seedrng.lock)"
//usage: "\n -n, --skip-credit Skip crediting seeds, even if creditable"
#include "libbb.h"
@@ -65,14 +64,7 @@
#define GRND_INSECURE 0x0004 /* Apparently some headers don't ship with this yet. */
#endif
-#if ENABLE_PID_FILE_PATH
-#define PID_FILE_PATH CONFIG_PID_FILE_PATH
-#else
-#define PID_FILE_PATH "/var/run"
-#endif
-
#define DEFAULT_SEED_DIR "/var/lib/seedrng"
-#define DEFAULT_LOCK_FILE PID_FILE_PATH "/seedrng.lock"
#define CREDITABLE_SEED_NAME "seed.credit"
#define NON_CREDITABLE_SEED_NAME "seed.no-credit"
@@ -116,8 +108,6 @@ static int read_new_seed(uint8_t *seed, size_t len, bool *is_creditable)
return 0;
if (open_read_close("/dev/urandom", seed, len) == (ssize_t)len)
return 0;
- if (!errno)
- errno = EIO;
return -1;
}
@@ -155,34 +145,29 @@ static int seed_from_file_if_exists(const char *filename, int dfd, bool credit,
{
uint8_t seed[MAX_SEED_LEN];
ssize_t seed_len;
- int ret = 0;
seed_len = open_read_close(filename, seed, sizeof(seed));
if (seed_len < 0) {
- if (errno != ENOENT) {
- ret = -errno;
- bb_simple_perror_msg("unable to read seed file");
- }
- goto out;
+ if (errno == ENOENT)
+ return 0;
+ bb_simple_perror_msg("unable to read seed file");
+ return -1;
}
if ((unlink(filename) < 0 || fsync(dfd) < 0) && seed_len) {
- ret = -errno;
bb_simple_perror_msg("unable to remove seed after reading, so not seeding");
- goto out;
- }
- if (!seed_len)
- goto out;
+ return -1;
+ } else if (!seed_len)
+ return 0;
sha256_hash(hash, &seed_len, sizeof(seed_len));
sha256_hash(hash, seed, seed_len);
printf("Seeding %zd bits %s crediting\n", seed_len * 8, credit ? "and" : "without");
- ret = seed_rng(seed, seed_len, credit);
- if (ret < 0)
+ if (seed_rng(seed, seed_len, credit) < 0) {
bb_simple_perror_msg("unable to seed");
-out:
- errno = -ret;
- return ret ? -1 : 0;
+ return -1;
+ }
+ return 0;
}
int seedrng_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
@@ -190,8 +175,8 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
{
static const char seedrng_prefix[] = "SeedRNG v1 Old+New Prefix";
static const char seedrng_failure[] = "SeedRNG v1 No New Seed Failure";
- char *seed_dir, *lock_file, *creditable_seed, *non_creditable_seed;
- int ret, fd = -1, dfd = -1, lock, program_ret = 0;
+ char *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;
bool new_seed_creditable;
@@ -202,22 +187,18 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
int opt;
enum {
OPT_d = (1 << 0),
- OPT_l = (1 << 1),
- OPT_n = (1 << 2)
+ OPT_n = (1 << 1)
};
#if ENABLE_LONG_OPTS
static const char longopts[] ALIGN1 =
"seed-dir\0" Required_argument "d"
- "lock-file\0" Required_argument "l"
"skip-credit\0" No_argument "n"
;
#endif
- opt = getopt32long(argv, "d:l:n", longopts, &seed_dir, &lock_file);
+ opt = getopt32long(argv, "d:n", longopts, &seed_dir);
if (!(opt & OPT_d) || !seed_dir)
seed_dir = xstrdup(DEFAULT_SEED_DIR);
- if (!(opt & OPT_l) || !lock_file)
- lock_file = xstrdup(DEFAULT_LOCK_FILE);
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);
@@ -229,16 +210,9 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
if (mkdir(seed_dir, 0700) < 0 && errno != EEXIST)
bb_simple_perror_msg_and_die("unable to create seed directory");
- lock = open(lock_file, O_WRONLY | O_CREAT, 0000);
- if (lock < 0 || flock(lock, LOCK_EX) < 0) {
- bb_simple_perror_msg("unable to open lock file");
- program_ret = 1;
- goto out;
- }
-
dfd = open(seed_dir, O_DIRECTORY | O_RDONLY);
- if (dfd < 0) {
- bb_simple_perror_msg("unable to open seed directory");
+ if (dfd < 0 || flock(dfd, LOCK_EX) < 0) {
+ bb_simple_perror_msg("unable to open and lock seed directory");
program_ret = 1;
goto out;
}
@@ -271,26 +245,19 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
printf("Saving %zu bits of %s seed for next boot\n", new_seed_len * 8, new_seed_creditable ? "creditable" : "non-creditable");
fd = open(non_creditable_seed, O_WRONLY | O_CREAT | O_TRUNC, 0400);
- if (fd < 0) {
- bb_simple_perror_msg("unable to open seed file for writing");
- program_ret |= 1 << 4;
- goto out;
- }
- if (write(fd, new_seed, new_seed_len) != (ssize_t)new_seed_len || fsync(fd) < 0) {
+ 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");
- program_ret |= 1 << 5;
+ program_ret |= 1 << 4;
goto out;
}
if (new_seed_creditable && rename(non_creditable_seed, creditable_seed) < 0) {
bb_simple_perror_msg("unable to make new seed creditable");
- program_ret |= 1 << 6;
+ program_ret |= 1 << 5;
}
out:
if (ENABLE_FEATURE_CLEAN_UP && fd >= 0)
close(fd);
if (ENABLE_FEATURE_CLEAN_UP && dfd >= 0)
close(dfd);
- if (ENABLE_FEATURE_CLEAN_UP && lock >= 0)
- close(lock);
return program_ret;
}