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| author | Junio C Hamano <gitster@pobox.com> | 2025-01-21 08:44:53 -0800 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2025-01-21 08:44:53 -0800 |
| commit | cb441e1ec3f3cf475d9037a4ce74e8fccd6be7d8 (patch) | |
| tree | 235fe13d72cc2897e498dbdd5d7a9ab0ad7c5415 | |
| parent | 57ebdd5af4031ddd0e012e68c5e423fd0671ed8c (diff) | |
| parent | 0b4f8afef6b744d5aa92883c5a6c1985be67cc7c (diff) | |
| download | git-cb441e1ec3f3cf475d9037a4ce74e8fccd6be7d8.tar.gz | |
Merge branch 'ps/reftable-get-random-fix'
The code to compute "unique" name used git_rand() which can fail or
get stuck; the callsite does not require cryptographic security.
Introduce the "insecure" mode and use it appropriately.
* ps/reftable-get-random-fix:
reftable/stack: accept insecure random bytes
wrapper: allow generating insecure random bytes
| -rw-r--r-- | builtin/gc.c | 2 | ||||
| -rw-r--r-- | reftable/stack.c | 4 | ||||
| -rw-r--r-- | t/helper/test-csprng.c | 2 | ||||
| -rw-r--r-- | t/unit-tests/t-reftable-readwrite.c | 6 | ||||
| -rw-r--r-- | wrapper.c | 24 | ||||
| -rw-r--r-- | wrapper.h | 16 |
6 files changed, 33 insertions, 21 deletions
diff --git a/builtin/gc.c b/builtin/gc.c index a9b1c36de2..3e754f25bb 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -1909,7 +1909,7 @@ static int get_random_minute(void) if (getenv("GIT_TEST_MAINT_SCHEDULER")) return 13; - return git_rand() % 60; + return git_rand(0) % 60; } static int is_launchctl_available(void) diff --git a/reftable/stack.c b/reftable/stack.c index 531660a49f..572a74e00f 100644 --- a/reftable/stack.c +++ b/reftable/stack.c @@ -493,7 +493,7 @@ static int reftable_stack_reload_maybe_reuse(struct reftable_stack *st, close(fd); fd = -1; - delay = delay + (delay * rand()) / RAND_MAX + 1; + delay = delay + (delay * git_rand(CSPRNG_BYTES_INSECURE)) / UINT32_MAX + 1; sleep_millisec(delay); } @@ -659,7 +659,7 @@ int reftable_stack_add(struct reftable_stack *st, static int format_name(struct reftable_buf *dest, uint64_t min, uint64_t max) { char buf[100]; - uint32_t rnd = (uint32_t)git_rand(); + uint32_t rnd = git_rand(CSPRNG_BYTES_INSECURE); snprintf(buf, sizeof(buf), "0x%012" PRIx64 "-0x%012" PRIx64 "-%08x", min, max, rnd); reftable_buf_reset(dest); diff --git a/t/helper/test-csprng.c b/t/helper/test-csprng.c index a4a0aca617..c86dcc4870 100644 --- a/t/helper/test-csprng.c +++ b/t/helper/test-csprng.c @@ -15,7 +15,7 @@ int cmd__csprng(int argc, const char **argv) while (count) { unsigned long chunk = count < sizeof(buf) ? count : sizeof(buf); - if (csprng_bytes(buf, chunk) < 0) { + if (csprng_bytes(buf, chunk, 0) < 0) { perror("failed to read"); return 5; } diff --git a/t/unit-tests/t-reftable-readwrite.c b/t/unit-tests/t-reftable-readwrite.c index 6b75a419b9..f22b977563 100644 --- a/t/unit-tests/t-reftable-readwrite.c +++ b/t/unit-tests/t-reftable-readwrite.c @@ -108,8 +108,8 @@ static void t_log_buffer_size(void) hash, to ensure that the compressed part is larger than the original. */ for (i = 0; i < REFTABLE_HASH_SIZE_SHA1; i++) { - log.value.update.old_hash[i] = (uint8_t)(git_rand() % 256); - log.value.update.new_hash[i] = (uint8_t)(git_rand() % 256); + log.value.update.old_hash[i] = (uint8_t)(git_rand(0) % 256); + log.value.update.new_hash[i] = (uint8_t)(git_rand(0) % 256); } reftable_writer_set_limits(w, update_index, update_index); err = reftable_writer_add_log(w, &log); @@ -325,7 +325,7 @@ static void t_log_zlib_corruption(void) }; for (i = 0; i < sizeof(message) - 1; i++) - message[i] = (uint8_t)(git_rand() % 64 + ' '); + message[i] = (uint8_t)(git_rand(0) % 64 + ' '); reftable_writer_set_limits(w, 1, 1); @@ -479,7 +479,7 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode) for (count = 0; count < TMP_MAX; ++count) { int i; uint64_t v; - if (csprng_bytes(&v, sizeof(v)) < 0) + if (csprng_bytes(&v, sizeof(v), 0) < 0) return error_errno("unable to get random bytes for temporary file"); /* Fill in the random bits. */ @@ -750,7 +750,7 @@ int open_nofollow(const char *path, int flags) #endif } -int csprng_bytes(void *buf, size_t len) +int csprng_bytes(void *buf, size_t len, MAYBE_UNUSED unsigned flags) { #if defined(HAVE_ARC4RANDOM) || defined(HAVE_ARC4RANDOM_LIBBSD) /* This function never returns an error. */ @@ -785,14 +785,18 @@ int csprng_bytes(void *buf, size_t len) return -1; return 0; #elif defined(HAVE_OPENSSL_CSPRNG) - int res = RAND_bytes(buf, len); - if (res == 1) + switch (RAND_pseudo_bytes(buf, len)) { + case 1: return 0; - if (res == -1) - errno = ENOTSUP; - else + case 0: + if (flags & CSPRNG_BYTES_INSECURE) + return 0; errno = EIO; - return -1; + return -1; + default: + errno = ENOTSUP; + return -1; + } #else ssize_t res; char *p = buf; @@ -816,11 +820,11 @@ int csprng_bytes(void *buf, size_t len) #endif } -uint32_t git_rand(void) +uint32_t git_rand(unsigned flags) { uint32_t result; - if (csprng_bytes(&result, sizeof(result)) < 0) + if (csprng_bytes(&result, sizeof(result), flags) < 0) die(_("unable to get random bytes")); return result; @@ -127,18 +127,26 @@ int open_nofollow(const char *path, int flags); void sleep_millisec(int millisec); +enum { + /* + * Accept insecure bytes, which some CSPRNG implementations may return + * in case the entropy pool has been exhausted. + */ + CSPRNG_BYTES_INSECURE = (1 << 0), +}; + /* * Generate len bytes from the system cryptographically secure PRNG. * Returns 0 on success and -1 on error, setting errno. The inability to - * satisfy the full request is an error. + * satisfy the full request is an error. Accepts CSPRNG flags. */ -int csprng_bytes(void *buf, size_t len); +int csprng_bytes(void *buf, size_t len, unsigned flags); /* * Returns a random uint32_t, uniformly distributed across all possible - * values. + * values. Accepts CSPRNG flags. */ -uint32_t git_rand(void); +uint32_t git_rand(unsigned flags); /* Provide log2 of the given `size_t`. */ static inline unsigned log2u(uintmax_t sz) |