rand: fix recursive locking issue.

The calls to query the DRBG strength, state and maximum output size all used
nested locks.  This removes the nesting.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/12321)
This commit is contained in:
Pauli 2020-06-30 09:36:47 +10:00
parent 8c1cbc7210
commit 132abb21f9

View File

@ -194,6 +194,7 @@ static void *evp_rand_from_dispatch(int name_id,
if (rand->get_ctx_params != NULL)
break;
rand->get_ctx_params = OSSL_FUNC_rand_get_ctx_params(fns);
fnctxcnt++;
break;
case OSSL_FUNC_RAND_SET_CTX_PARAMS:
if (rand->set_ctx_params != NULL)
@ -220,7 +221,7 @@ static void *evp_rand_from_dispatch(int name_id,
* locking functions.
*/
if (fnrandcnt != 3
|| fnctxcnt != 2
|| fnctxcnt != 3
|| (fnlockcnt != 0 && fnlockcnt != 3)
#ifdef FIPS_MODULE
|| fnzeroizecnt != 1
@ -340,14 +341,12 @@ EVP_RAND *EVP_RAND_CTX_rand(EVP_RAND_CTX *ctx)
int EVP_RAND_get_ctx_params(EVP_RAND_CTX *ctx, OSSL_PARAM params[])
{
int res = 1;
int res;
if (ctx->meth->get_ctx_params != NULL) {
if (!evp_rand_lock(ctx))
return 0;
res = ctx->meth->get_ctx_params(ctx->data, params);
evp_rand_unlock(ctx);
}
if (!evp_rand_lock(ctx))
return 0;
res = ctx->meth->get_ctx_params(ctx->data, params);
evp_rand_unlock(ctx);
return res;
}
@ -440,7 +439,8 @@ int EVP_RAND_generate(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen,
params[0] = OSSL_PARAM_construct_size_t(OSSL_DRBG_PARAM_MAX_REQUEST,
&chunk);
params[1] = OSSL_PARAM_construct_end();
if (!EVP_RAND_get_ctx_params(ctx, params) || chunk == 0) {
/* Cannot call EVP_RAND_get_ctx_params() since we have the lock */
if (!ctx->meth->get_ctx_params(ctx->data, params) || chunk == 0) {
EVPerr(0, EVP_R_UNABLE_TO_GET_MAXIMUM_REQUEST_SIZE);
goto err;
}
@ -497,19 +497,15 @@ int EVP_RAND_nonce(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen)
unsigned int EVP_RAND_strength(EVP_RAND_CTX *ctx)
{
OSSL_PARAM params[2];
unsigned int t;
int res;
if (ctx->strength == 0) {
params[0] = OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH, &t);
params[0] = OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH,
&ctx->strength);
params[1] = OSSL_PARAM_construct_end();
if (!evp_rand_lock(ctx))
return 0;
res = EVP_RAND_get_ctx_params(ctx, params);
evp_rand_unlock(ctx);
if (!res)
return 0;
ctx->strength = t;
}
return ctx->strength;
}
@ -521,10 +517,7 @@ int EVP_RAND_state(EVP_RAND_CTX *ctx)
params[0] = OSSL_PARAM_construct_int(OSSL_RAND_PARAM_STATE,
&status);
if (!evp_rand_lock(ctx))
return 0;
res = EVP_RAND_get_ctx_params(ctx, params);
evp_rand_unlock(ctx);
if (!res)
status = EVP_RAND_STATE_ERROR;
return status;