diff --git a/changes/bug10402 b/changes/bug10402 new file mode 100644 index 000000000..eac00bdc6 --- /dev/null +++ b/changes/bug10402 @@ -0,0 +1,11 @@ + o Major bugfixes: + - Do not allow OpenSSL engines to replace the PRNG, even when + HardwareAccel is set. The only default builtin PRNG engine uses + the Intel RDRAND instruction to replace the entire PRNG, and + ignores all attempts to seed it with more entropy. That's + cryptographically stupid: the right response to a new alleged + entropy source is never to discard all previously used entropy + sources. Fixes bug 10402; works around behavior introduced in + OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman" + and "rl1987". + diff --git a/src/common/crypto.c b/src/common/crypto.c index 0ababeaea..940a756f6 100644 --- a/src/common/crypto.c +++ b/src/common/crypto.c @@ -169,8 +169,8 @@ log_engine(const char *fn, ENGINE *e) const char *name, *id; name = ENGINE_get_name(e); id = ENGINE_get_id(e); - log_notice(LD_CRYPTO, "Using OpenSSL engine %s [%s] for %s", - name?name:"?", id?id:"?", fn); + log_notice(LD_CRYPTO, "Default OpenSSL engine for %s is %s [%s]", + fn, name?name:"?", id?id:"?"); } else { log_info(LD_CRYPTO, "Using default implementation for %s", fn); } @@ -288,7 +288,7 @@ crypto_global_init(int useAccel, const char *accelName, const char *accelDir) } log_engine("RSA", ENGINE_get_default_RSA()); log_engine("DH", ENGINE_get_default_DH()); - log_engine("RAND", ENGINE_get_default_RAND()); + log_engine("RAND (which we will not use)", ENGINE_get_default_RAND()); log_engine("SHA1", ENGINE_get_digest_engine(NID_sha1)); log_engine("3DES", ENGINE_get_cipher_engine(NID_des_ede3_ecb)); log_engine("AES", ENGINE_get_cipher_engine(NID_aes_128_ecb)); @@ -297,6 +297,13 @@ crypto_global_init(int useAccel, const char *accelName, const char *accelDir) log_info(LD_CRYPTO, "NOT using OpenSSL engine support."); } + if (RAND_get_rand_method() != RAND_SSLeay()) { + log_notice(LD_CRYPTO, "It appears that one of our engines has provided " + "a replacement the OpenSSL RNG. Resetting it to the default " + "implementation."); + RAND_set_rand_method(RAND_SSLeay()); + } + evaluate_evp_for_aes(-1); evaluate_ctr_for_aes();