From 3c64a236dfecbe396766ec0e8d326443358d4ab3 Mon Sep 17 00:00:00 2001 From: Andreas Schneider Date: Mon, 4 Nov 2019 17:01:50 +0100 Subject: [PATCH 192/208] lib:crypto: Add samba_gnutls_weak_crypto() Signed-off-by: Andreas Schneider --- lib/crypto/gnutls_helpers.h | 7 +++++ lib/crypto/gnutls_weak_crypto.c | 48 +++++++++++++++++++++++++++++++++ lib/crypto/wscript_build | 1 + 3 files changed, 56 insertions(+) create mode 100644 lib/crypto/gnutls_weak_crypto.c diff --git a/lib/crypto/gnutls_helpers.h b/lib/crypto/gnutls_helpers.h index d6000c7b316..a985c028e9d 100644 --- a/lib/crypto/gnutls_helpers.h +++ b/lib/crypto/gnutls_helpers.h @@ -92,4 +92,11 @@ int samba_gnutls_arcfour_confounded_md5(const DATA_BLOB *key_input1, DATA_BLOB *data, enum samba_gnutls_direction encrypt); +/** + * @brief Check if weak crypto is allowed. + * + * @return true if weak crypo is allowed, false otherwise. + */ +bool samba_gnutls_weak_crypto_allowed(void); + #endif /* _GNUTLS_HELPERS_H */ diff --git a/lib/crypto/gnutls_weak_crypto.c b/lib/crypto/gnutls_weak_crypto.c new file mode 100644 index 00000000000..68ce588243f --- /dev/null +++ b/lib/crypto/gnutls_weak_crypto.c @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2019 Andreas Schneider + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include "includes.h" +#include "lib/crypto/gnutls_helpers.h" + +#include +#include + +bool samba_gnutls_weak_crypto_allowed(void) +{ + gnutls_cipher_hd_t cipher_hnd = NULL; + gnutls_datum_t key = { + .data = discard_const_p(unsigned char, "SystemLibraryDTC"), + .size = 16, + }; + int rc; + + /* + * If RC4 is not allowed to be initialzed then weak crypto is not + * allowed. + */ + rc = gnutls_cipher_init(&cipher_hnd, + GNUTLS_CIPHER_ARCFOUR_128, + &key, + NULL); + if (rc == GNUTLS_E_UNWANTED_ALGORITHM) { + return false; + } + + gnutls_cipher_deinit(cipher_hnd); + + return true; +} diff --git a/lib/crypto/wscript_build b/lib/crypto/wscript_build index eb67af63f26..e5766042541 100644 --- a/lib/crypto/wscript_build +++ b/lib/crypto/wscript_build @@ -10,6 +10,7 @@ bld.SAMBA_SUBSYSTEM('GNUTLS_HELPERS', source=''' gnutls_error.c gnutls_arcfour_confounded_md5.c + gnutls_weak_crypto.c ''', deps='gnutls samba-errors'); -- 2.23.0