diff options
author | Pauli <ppzgs1@gmail.com> | 2021-02-12 12:44:21 +1000 |
---|---|---|
committer | Pauli <ppzgs1@gmail.com> | 2021-02-17 13:10:49 +1000 |
commit | 9ed185a926cc1b8527bba8efa28a6b15392484ce (patch) | |
tree | cc2e501cf9ea895cf3756aa25f0176b21842e354 | |
parent | 381289f6c7bd0e782cfd97d21c80656e470064d7 (diff) |
RNG seed: add get_entropy hook for seeding.
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/14162)
-rw-r--r-- | providers/implementations/rands/seed_src.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/providers/implementations/rands/seed_src.c b/providers/implementations/rands/seed_src.c index 60088b2779..c93036cb60 100644 --- a/providers/implementations/rands/seed_src.c +++ b/providers/implementations/rands/seed_src.c @@ -34,6 +34,8 @@ static OSSL_FUNC_rand_verify_zeroization_fn seed_src_verify_zeroization; static OSSL_FUNC_rand_enable_locking_fn seed_src_enable_locking; static OSSL_FUNC_rand_lock_fn seed_src_lock; static OSSL_FUNC_rand_unlock_fn seed_src_unlock; +static OSSL_FUNC_rand_get_seed_fn seed_get_seed; +static OSSL_FUNC_rand_clear_seed_fn seed_clear_seed; typedef struct { void *provctx; @@ -170,6 +172,47 @@ static int seed_src_verify_zeroization(ossl_unused void *vseed) return 1; } +static size_t seed_get_seed(void *vseed, unsigned char **pout, + int entropy, size_t min_len, size_t max_len, + int prediction_resistance, + const unsigned char *adin, size_t adin_len) +{ + size_t bytes_needed; + unsigned char *p; + + /* + * Figure out how many bytes we need. + * This assumes that the seed sources provide eight bits of entropy + * per byte. For lower quality sources, the formula will need to be + * different. + */ + bytes_needed = entropy >= 0 ? (entropy + 7) / 8 : 0; + if (bytes_needed < min_len) + bytes_needed = min_len; + if (bytes_needed > max_len) { + ERR_raise(ERR_LIB_PROV, PROV_R_ENTROPY_SOURCE_STRENGTH_TOO_WEAK); + return 0; + } + + p = OPENSSL_secure_malloc(bytes_needed); + if (p == NULL) { + ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); + return 0; + } + *pout = p; + if (seed_src_generate(vseed, p, bytes_needed, 0, prediction_resistance, + adin, adin_len) != 0) + return bytes_needed; + OPENSSL_secure_clear_free(p, bytes_needed); + return 0; +} + +static void seed_clear_seed(ossl_unused void *vdrbg, + unsigned char *out, size_t outlen) +{ + OPENSSL_secure_clear_free(out, outlen); +} + static int seed_src_enable_locking(ossl_unused void *vseed) { return 1; @@ -201,5 +244,7 @@ const OSSL_DISPATCH ossl_seed_src_functions[] = { { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))seed_src_get_ctx_params }, { OSSL_FUNC_RAND_VERIFY_ZEROIZATION, (void(*)(void))seed_src_verify_zeroization }, + { OSSL_FUNC_RAND_GET_SEED, (void(*)(void))seed_get_seed }, + { OSSL_FUNC_RAND_CLEAR_SEED, (void(*)(void))seed_clear_seed }, { 0, NULL } }; |