Adding upstream version 7.94+git20230807.3be01efb1+dfsg.upstream/7.94+git20230807.3be01efb1+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 278 insertions, 0 deletions

diff --git a/nsock/src/nsock_ssl.c b/nsock/src/nsock_ssl.c
new file mode 100644
index 0000000..096ce72
--- /dev/null
+++ b/nsock/src/nsock_ssl.c
@@ -0,0 +1,278 @@
+/***************************************************************************
+ * nsock_ssl.c -- This contains functions that relate somewhat exclusively *
+ * to SSL (over TCP) support in nsock.  Where SSL support is incidental,   *
+ * it is often in other files where code can be more easily shared between *
+ * the SSL and NonSSL paths.                                               *
+ *                                                                         *
+ ***********************IMPORTANT NSOCK LICENSE TERMS***********************
+ *
+ * The nsock parallel socket event library is (C) 1999-2023 Nmap Software LLC
+ * This library is free software; you may redistribute and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation; Version 2. This guarantees your right to use, modify, and
+ * redistribute this software under certain conditions. If this license is
+ * unacceptable to you, Nmap Software LLC may be willing to sell alternative
+ * licenses (contact sales@nmap.com ).
+ *
+ * As a special exception to the GPL terms, Nmap Software LLC grants permission
+ * to link the code of this program with any version of the OpenSSL library
+ * which is distributed under a license identical to that listed in the included
+ * docs/licenses/OpenSSL.txt file, and distribute linked combinations including
+ * the two. You must obey the GNU GPL in all respects for all of the code used
+ * other than OpenSSL. If you modify this file, you may extend this exception to
+ * your version of the file, but you are not obligated to do so.
+ *
+ * If you received these files with a written license agreement stating terms
+ * other than the (GPL) terms above, then that alternative license agreement
+ * takes precedence over this comment.
+ *
+ * Source is provided to this software because we believe users have a right to
+ * know exactly what a program is going to do before they run it. This also
+ * allows you to audit the software for security holes.
+ *
+ * Source code also allows you to port Nmap to new platforms, fix bugs, and add
+ * new features. You are highly encouraged to send your changes to the
+ * dev@nmap.org mailing list for possible incorporation into the main
+ * distribution. By sending these changes to Fyodor or one of the Insecure.Org
+ * development mailing lists, or checking them into the Nmap source code
+ * repository, it is understood (unless you specify otherwise) that you are
+ * offering the Nmap Project (Nmap Software LLC) the unlimited, non-exclusive
+ * right to reuse, modify, and relicense the code. Nmap will always be available
+ * Open Source, but this is important because the inability to relicense code
+ * has caused devastating problems for other Free Software projects (such as KDE
+ * and NASM). We also occasionally relicense the code to third parties as
+ * discussed above. If you wish to specify special license conditions of your
+ * contributions, just say so when you send them.
+ *
+ * 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 v2.0 for more
+ * details (http://www.gnu.org/licenses/gpl-2.0.html).
+ *
+ ***************************************************************************/
+
+/* $Id$ */
+
+
+#include "nsock.h"
+#include "nsock_internal.h"
+#include "nsock_log.h"
+#include "nsock_ssl.h"
+#include "netutils.h"
+
+#if HAVE_OPENSSL
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+#include <openssl/provider.h>
+#endif
+
+/* Disallow anonymous ciphers (Diffie-Hellman key agreement), low bit-strength
+ * ciphers, export-crippled ciphers, and MD5. Prefer ciphers in decreasing order
+ * of key size. The cipher list is taken from the book Network Security with
+ *  OpenSSL. To see exactly what ciphers are enabled, use the command
+ *   openssl ciphers -v '...'
+ * where ... is the string below. */
+#define CIPHERS_SECURE "ALL:!aNULL:!eNULL:!LOW:!EXP:!RC4:!MD5:@STRENGTH"
+
+/* This list of ciphers is for speed and compatibility, not security. Any cipher
+ *  is accepted, and the list is sorted by speed based on Brian Hatch's
+ *  (bri@ifokr.org) tests on an Pentium 686 against the ciphers listed. */
+#define CIPHERS_FAST "RC4-SHA:RC4-MD5:NULL-SHA:EXP-DES-CBC-SHA:EXP-EDH-RSA-DES-CBC-SHA:EXP-RC4-MD5:NULL-MD5:EDH-RSA-DES-CBC-SHA:EXP-RC2-CBC-MD5:EDH-RSA-DES-CBC3-SHA:EXP-ADH-RC4-MD5:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:EXP-ADH-DES-CBC-SHA:ADH-AES256-SHA:ADH-DES-CBC-SHA:ADH-RC4-MD5:AES256-SHA:DES-CBC-SHA:DES-CBC3-SHA:ADH-DES-CBC3-SHA:AES128-SHA:ADH-AES128-SHA:eNULL:ALL"
+
+extern struct timeval nsock_tod;
+#define NSOCK_SSL_STATE_UNINITIALIZED -1
+#define NSOCK_SSL_STATE_INITIALIZED 1
+#define NSOCK_SSL_STATE_ATEXIT 0
+static int nsock_ssl_state = NSOCK_SSL_STATE_UNINITIALIZED;
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined LIBRESSL_VERSION_NUMBER
+static void nsock_ssl_atexit(void)
+{
+  nsock_ssl_state = NSOCK_SSL_STATE_ATEXIT;
+}
+#endif
+void nsp_ssl_cleanup(struct npool *nsp)
+{
+  if (nsock_ssl_state != NSOCK_SSL_STATE_ATEXIT)
+  {
+    if (nsp->sslctx != NULL)
+      SSL_CTX_free(nsp->sslctx);
+#ifdef HAVE_DTLS_CLIENT_METHOD
+    if (nsp->dtlsctx != NULL)
+      SSL_CTX_free(nsp->dtlsctx);
+#endif
+  }
+  nsp->sslctx = NULL;
+#ifdef HAVE_DTLS_CLIENT_METHOD
+  nsp->dtlsctx = NULL;
+#endif
+}
+
+static SSL_CTX *ssl_init_helper(const SSL_METHOD *method) {
+  SSL_CTX *ctx;
+
+  if (nsock_ssl_state == NSOCK_SSL_STATE_UNINITIALIZED)
+  {
+    nsock_ssl_state = NSOCK_SSL_STATE_INITIALIZED;
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined LIBRESSL_VERSION_NUMBER
+    SSL_load_error_strings();
+    SSL_library_init();
+#else
+    OPENSSL_atexit(nsock_ssl_atexit);
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+    if (NULL == OSSL_PROVIDER_load(NULL, "legacy"))
+    {
+      nsock_log_info("OpenSSL legacy provider failed to load: %s",
+          ERR_error_string(ERR_get_error(), NULL));
+    }
+    if (NULL == OSSL_PROVIDER_load(NULL, "default"))
+    {
+      nsock_log_error("OpenSSL default provider failed to load: %s",
+          ERR_error_string(ERR_get_error(), NULL));
+    }
+#endif
+#endif
+  }
+
+  ctx = SSL_CTX_new(method);
+  if (!ctx) {
+    fatal("OpenSSL failed to create a new SSL_CTX: %s",
+          ERR_error_string(ERR_get_error(), NULL));
+  }
+
+  /* Our SSL* will always have the SSL_SESSION* inside it, so we neither need to
+   * use nor waste memory for the session cache.  (Use '1' because '0' means
+   * 'infinite'.)   */
+  SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF|SSL_SESS_CACHE_NO_AUTO_CLEAR);
+  SSL_CTX_sess_set_cache_size(ctx, 1);
+  SSL_CTX_set_timeout(ctx, 3600); /* pretty unnecessary */
+
+  return ctx;
+}
+
+/* Create an SSL_CTX and do initialization that is common to all init modes. */
+static SSL_CTX *ssl_init_common() {
+  return ssl_init_helper(SSLv23_client_method());
+}
+
+/* Initializes an Nsock pool to create SSL connections. This sets an internal
+ * SSL_CTX, which is like a template that sets options for all connections that
+ * are made from it. The connections made from this context will use only secure
+ * ciphers but no server certificate verification is done. Returns the SSL_CTX
+ * so you can set your own options. */
+static nsock_ssl_ctx nsock_pool_ssl_init_helper(SSL_CTX *ctx, int flags) {
+  char rndbuf[128];
+
+  /* Get_random_bytes may or may not provide high-quality randomness. Add it to
+   * the entropy pool without increasing the entropy estimate (third argument of
+   * RAND_add is 0). We rely on OpenSSL's entropy gathering, called implicitly
+   * by RAND_status, to give us what we need, or else bail out if it fails. */
+  get_random_bytes(rndbuf, sizeof(rndbuf));
+  RAND_add(rndbuf, sizeof(rndbuf), 0);
+
+  if (!(flags & NSOCK_SSL_MAX_SPEED)) {
+    if (!RAND_status())
+      fatal("%s: Failed to seed OpenSSL PRNG"
+            " (RAND_status returned false).", __func__);
+  }
+
+  /* SSL_OP_ALL sets bug-compatibility for pretty much everything.
+   * SSL_OP_NO_SSLv2 disables the less-secure SSLv2 while allowing us to use the
+   * SSLv2-compatible SSLv23_client_method. */
+  SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+  SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2);
+  SSL_CTX_set_options(ctx, flags & NSOCK_SSL_MAX_SPEED ?
+                                  SSL_OP_ALL : SSL_OP_ALL|SSL_OP_NO_SSLv2);
+
+  if (!SSL_CTX_set_cipher_list(ctx, flags & NSOCK_SSL_MAX_SPEED ?
+                                           CIPHERS_FAST : CIPHERS_SECURE))
+    fatal("Unable to set OpenSSL cipher list: %s",
+          ERR_error_string(ERR_get_error(), NULL));
+
+  return ctx;
+}
+
+nsock_ssl_ctx nsock_pool_ssl_init(nsock_pool ms_pool, int flags) {
+  struct npool *ms = (struct npool *)ms_pool;
+
+  if (ms->sslctx == NULL)
+    ms->sslctx = ssl_init_common();
+  return nsock_pool_ssl_init_helper(ms->sslctx, flags);
+}
+
+#ifdef HAVE_DTLS_CLIENT_METHOD
+
+/* Create an SSL_CTX and do initialisation, creating a DTLS client */
+static SSL_CTX *dtls_init_common() {
+  return ssl_init_helper(DTLS_client_method());
+}
+
+/* Initializes an Nsock pool to create DTLS connections. Very much similar to
+ * nsock_pool_ssl_init, just with DTLS. */
+nsock_ssl_ctx nsock_pool_dtls_init(nsock_pool ms_pool, int flags) {
+  SSL_CTX *dtls_ctx = NULL;
+  struct npool *ms = (struct npool *)ms_pool;
+
+  if (ms->dtlsctx == NULL)
+    ms->dtlsctx = dtls_init_common();
+  dtls_ctx = (SSL_CTX *) nsock_pool_ssl_init_helper(ms->dtlsctx, flags);
+
+  /* Don't add padding or the ClientHello will fragment and not connect properly. */
+  SSL_CTX_clear_options(dtls_ctx, SSL_OP_TLSEXT_PADDING);
+
+  if (!SSL_CTX_set_cipher_list(dtls_ctx, "DEFAULT"))
+    fatal("Unable to set OpenSSL cipher list: %s",
+          ERR_error_string(ERR_get_error(), NULL));
+
+  return dtls_ctx;
+}
+
+#else /* OpenSSL Version does not support DTLS */
+
+nsock_ssl_ctx nsock_pool_dtls_init(nsock_pool ms_pool, int flags) {
+  fatal("%s called with no OpenSSL DTLS support", __func__);
+}
+
+#endif
+
+/* Check server certificate verification, after a connection is established. We
+ * check first that a certificate was even offered, then call
+ * SSL_get_verify_result to get the overall status of verification. (Just
+ * calling SSL_get_verify_result is not enough because that function returns
+ * X509_V_OK when 0 certificates are presented.) If the verification mode of the
+ * SSL object is SSL_VERIFY_NONE, or if OpenSSL is disabled, this function
+ * always returns true. */
+int nsi_ssl_post_connect_verify(const nsock_iod nsockiod) {
+  struct niod *iod = (struct niod *)nsockiod;
+
+  assert(iod->ssl != NULL);
+  if (SSL_get_verify_mode(iod->ssl) != SSL_VERIFY_NONE) {
+    X509 *cert;
+
+    cert = SSL_get_peer_certificate(iod->ssl);
+    if (cert == NULL)
+      /* No certificate presented. */
+      return 0;
+
+    X509_free(cert);
+
+    if (SSL_get_verify_result(iod->ssl) != X509_V_OK)
+      /* Something wrong with verification. */
+      return 0;
+  }
+  return 1;
+}
+
+#else /* NOT HAVE_OPENSSL */
+
+nsock_ssl_ctx nsock_pool_ssl_init(nsock_pool ms_pool, int flags) {
+  fatal("%s called with no OpenSSL support", __func__);
+}
+
+nsock_ssl_ctx nsock_pool_dtls_init(nsock_pool ms_pool, int flags) {
+  fatal("%s called with no OpenSSL support", __func__);
+}
+
+int nsi_ssl_post_connect_verify(const nsock_iod nsockiod) {
+  return 1;
+}
+
+#endif