diff options
| author | Ted Unangst <tedu@cvs.openbsd.org> | 2014-12-29 16:13:00 +0000 |
|---|---|---|
| committer | Ted Unangst <tedu@cvs.openbsd.org> | 2014-12-29 16:13:00 +0000 |
| commit | 128992068667afb8ad28f7bc105cfdc6e49f30d5 (patch) | |
| tree | 27bc3cd77a6193e61c00f9d44d5bbfdf87ebc93a | |
| parent | 041e47b9f433e7aa0a8c9570d49d2f07939eb5bb (diff) | |
don't leak timing info about padding errors by generating a fake key
afterwards. openssl has a more complicated fix, but it's less intrusive
for now to simply hoist the expensive part (fake key generation) up without
sweating a branch or two.
ok bcook jsing
| -rw-r--r-- | lib/libssl/src/ssl/s3_srvr.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/lib/libssl/src/ssl/s3_srvr.c b/lib/libssl/src/ssl/s3_srvr.c index 5e4a605c605..fd8f9aababf 100644 --- a/lib/libssl/src/ssl/s3_srvr.c +++ b/lib/libssl/src/ssl/s3_srvr.c @@ -1,4 +1,4 @@ -/* $OpenBSD: s3_srvr.c,v 1.95 2014/12/15 00:46:53 doug Exp $ */ +/* $OpenBSD: s3_srvr.c,v 1.96 2014/12/29 16:12:59 tedu Exp $ */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * @@ -1822,6 +1822,12 @@ ssl3_get_client_key_exchange(SSL *s) alg_k = s->s3->tmp.new_cipher->algorithm_mkey; if (alg_k & SSL_kRSA) { + char fakekey[SSL_MAX_MASTER_KEY_LENGTH]; + + arc4random_buf(fakekey, sizeof(fakekey)); + fakekey[0] = s->client_version >> 8; + fakekey[1] = s->client_version & 0xff; + pkey = s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey; if ((pkey == NULL) || (pkey->type != EVP_PKEY_RSA) || (pkey->pkey.rsa == NULL)) { @@ -1851,6 +1857,8 @@ ssl3_get_client_key_exchange(SSL *s) i = RSA_private_decrypt((int)n, p, p, rsa, RSA_PKCS1_PADDING); + ERR_clear_error(); + al = -1; if (i != SSL_MAX_MASTER_KEY_LENGTH) { @@ -1902,11 +1910,8 @@ ssl3_get_client_key_exchange(SSL *s) * on PKCS #1 v1.5 RSA padding (see RFC 2246, * section 7.4.7.1). */ - ERR_clear_error(); i = SSL_MAX_MASTER_KEY_LENGTH; - p[0] = s->client_version >> 8; - p[1] = s->client_version & 0xff; - arc4random_buf(p + 2, i - 2); + p = fakekey; } s->session->master_key_length = |