From 87975cfa91c3f06a52f2550ed2ef632644be6dde Mon Sep 17 00:00:00 2001 From: Richard Levitte Date: Thu, 6 Apr 2017 11:30:03 +0200 Subject: [PATCH] Make getting and setting the RAND default method thread safe Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/3137) --- crypto/rand/rand_lib.c | 37 +++++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c index ad452504e6..dc629022c3 100644 --- a/crypto/rand/rand_lib.c +++ b/crypto/rand/rand_lib.c @@ -12,27 +12,50 @@ #include "internal/cryptlib.h" #include #include "internal/rand.h" - #include +#include "internal/thread_once.h" #ifndef OPENSSL_NO_ENGINE /* non-NULL if default_RAND_meth is ENGINE-provided */ static ENGINE *funct_ref = NULL; +static CRYPTO_RWLOCK *rand_engine_lock = NULL; #endif static const RAND_METHOD *default_RAND_meth = NULL; +static CRYPTO_RWLOCK *rand_meth_lock = NULL; +static CRYPTO_ONCE rand_lock_init = CRYPTO_ONCE_STATIC_INIT; + +DEFINE_RUN_ONCE_STATIC(do_rand_lock_init) +{ +#ifndef OPENSSL_NO_ENGINE + rand_engine_lock = CRYPTO_THREAD_lock_new(); +#endif + rand_meth_lock = CRYPTO_THREAD_lock_new(); + return rand_engine_lock != NULL && rand_meth_lock != NULL; +} int RAND_set_rand_method(const RAND_METHOD *meth) { + if (!RUN_ONCE(&rand_lock_init, do_rand_lock_init)) + return 0; + + CRYPTO_THREAD_write_lock(rand_meth_lock); #ifndef OPENSSL_NO_ENGINE ENGINE_finish(funct_ref); funct_ref = NULL; #endif default_RAND_meth = meth; + CRYPTO_THREAD_unlock(rand_meth_lock); return 1; } const RAND_METHOD *RAND_get_rand_method(void) { + const RAND_METHOD *tmp_meth = NULL; + + if (!RUN_ONCE(&rand_lock_init, do_rand_lock_init)) + return NULL; + + CRYPTO_THREAD_write_lock(rand_meth_lock); if (!default_RAND_meth) { #ifndef OPENSSL_NO_ENGINE ENGINE *e = ENGINE_get_default_RAND(); @@ -49,13 +72,19 @@ const RAND_METHOD *RAND_get_rand_method(void) #endif default_RAND_meth = RAND_OpenSSL(); } - return default_RAND_meth; + tmp_meth = default_RAND_meth; + CRYPTO_THREAD_unlock(rand_meth_lock); + return tmp_meth; } #ifndef OPENSSL_NO_ENGINE int RAND_set_rand_engine(ENGINE *engine) { const RAND_METHOD *tmp_meth = NULL; + + if (!RUN_ONCE(&rand_lock_init, do_rand_lock_init)) + return 0; + if (engine) { if (!ENGINE_init(engine)) return 0; @@ -65,9 +94,11 @@ int RAND_set_rand_engine(ENGINE *engine) return 0; } } + CRYPTO_THREAD_write_lock(rand_engine_lock); /* This function releases any prior ENGINE so call it first */ RAND_set_rand_method(tmp_meth); funct_ref = engine; + CRYPTO_THREAD_unlock(rand_engine_lock); return 1; } #endif @@ -78,6 +109,8 @@ void rand_cleanup_int(void) if (meth && meth->cleanup) meth->cleanup(); RAND_set_rand_method(NULL); + CRYPTO_THREAD_lock_free(rand_meth_lock); + CRYPTO_THREAD_lock_free(rand_engine_lock); } void RAND_seed(const void *buf, int num) -- 2.25.1