X-Git-Url: http://sjero.net/git/?p=wget;a=blobdiff_plain;f=src%2Fopenssl.c;h=b725a065f8336aec2d15a3a923fb624f379e1793;hp=91552dee674da286b78a48bfc7678b784cd1c9ea;hb=38a7829dcb4eb5dba28dbf0f05c6a80fea9217f8;hpb=8f935cf74ce95a631788fb8a4cce4114df935a78
diff --git a/src/openssl.c b/src/openssl.c
index 91552dee..b725a065 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -1,12 +1,13 @@
/* SSL support via OpenSSL library.
- Copyright (C) 2000-2005 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+ 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
Originally contributed by Christian Fraenkel.
This file is part of GNU Wget.
GNU Wget 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 2 of the License, or
+the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
GNU Wget is distributed in the hope that it will be useful,
@@ -15,53 +16,43 @@ 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 Wget; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+along with Wget. If not, see .
-In addition, as a special exception, the Free Software Foundation
-gives permission to link the code of its release of Wget with the
-OpenSSL project's "OpenSSL" library (or with modified versions of it
-that use the same license as the "OpenSSL" library), and distribute
-the linked executables. You must obey the GNU General Public License
-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 do not wish to do
-so, delete this exception statement from your version. */
+Additional permission under GNU GPL version 3 section 7
-#include
+If you modify this program, or any covered work, by linking or
+combining it with the OpenSSL project's OpenSSL library (or a
+modified version of that library), containing parts covered by the
+terms of the OpenSSL or SSLeay licenses, the Free Software Foundation
+grants you additional permission to convey the resulting work.
+Corresponding Source for a non-source form of such a combination
+shall include the source code for the parts of OpenSSL used as well
+as that of the covered work. */
+
+#include "wget.h"
#include
#include
-#ifdef HAVE_UNISTD_H
-# include
-#endif
-#ifdef HAVE_STRING_H
-# include
-#else
-# include
-#endif
+#include
+#include
-#include
-#include
-#include
#include
+#include
#include
-#include
#include
-#include "wget.h"
#include "utils.h"
#include "connect.h"
#include "url.h"
#include "ssl.h"
-#ifndef errno
-extern int errno;
+#ifdef WINDOWS
+# include
#endif
/* Application-wide SSL context. This is common to all SSL
connections. */
-SSL_CTX *ssl_ctx;
+static SSL_CTX *ssl_ctx;
/* Initialize the SSL's PRNG using various methods. */
@@ -125,48 +116,21 @@ init_prng (void)
while (RAND_status () == 0 && maxrand-- > 0)
{
- unsigned char rnd = random_number (256);
- RAND_seed (&rnd, sizeof (rnd));
+ unsigned char rnd = random_number (256);
+ RAND_seed (&rnd, sizeof (rnd));
}
}
#endif
}
-/* #### Someone should audit and document this. */
-
-static int
-verify_callback (int ok, X509_STORE_CTX *ctx)
-{
- char buf[256];
- /* #### Why are we not using the result of this call? */
- X509_NAME_oneline (X509_get_subject_name (ctx->current_cert),
- buf, sizeof (buf));
- if (ok == 0)
- {
- switch (ctx->error)
- {
- case X509_V_ERR_CERT_NOT_YET_VALID:
- case X509_V_ERR_CERT_HAS_EXPIRED:
- /* This mean the CERT is not valid !!! */
- ok = 0;
- break;
- case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
- /* Unsure if we should handle that this way */
- ok = 1;
- break;
- }
- }
- return ok;
-}
-
/* Print errors in the OpenSSL error stack. */
static void
-print_errors (void)
+print_errors (void)
{
- unsigned long curerr = 0;
- while ((curerr = ERR_get_error ()) != 0)
- logprintf (LOG_NOTQUIET, "OpenSSL: %s\n", ERR_error_string (curerr, NULL));
+ unsigned long err;
+ while ((err = ERR_get_error ()) != 0)
+ logprintf (LOG_NOTQUIET, "OpenSSL: %s\n", ERR_error_string (err, NULL));
}
/* Convert keyfile type as used by options.h to a type as accepted by
@@ -192,23 +156,23 @@ key_type_to_ssl_type (enum keyfile_type type)
/* Create an SSL Context and set default paths etc. Called the first
time an HTTP download is attempted.
- Returns 0 on success, non-zero otherwise. */
+ Returns true on success, false otherwise. */
-int
-ssl_init ()
+bool
+ssl_init (void)
{
- SSL_METHOD *meth;
+ SSL_METHOD const *meth;
if (ssl_ctx)
/* The SSL has already been initialized. */
- return 1;
+ return true;
/* Init the PRNG. If that fails, bail out. */
init_prng ();
if (RAND_status () != 1)
{
logprintf (LOG_NOTQUIET,
- _("Could not seed PRNG; consider using --random-file.\n"));
+ _("Could not seed PRNG; consider using --random-file.\n"));
goto error;
}
@@ -222,12 +186,15 @@ ssl_init ()
case secure_protocol_auto:
meth = SSLv23_client_method ();
break;
+#ifndef OPENSSL_NO_SSL2
case secure_protocol_sslv2:
meth = SSLv2_client_method ();
break;
+#endif
case secure_protocol_sslv3:
meth = SSLv3_client_method ();
break;
+ case secure_protocol_pfs:
case secure_protocol_tlsv1:
meth = TLSv1_client_method ();
break;
@@ -235,137 +202,585 @@ ssl_init ()
abort ();
}
- ssl_ctx = SSL_CTX_new (meth);
+ /* The type cast below accommodates older OpenSSL versions (0.9.8)
+ where SSL_CTX_new() is declared without a "const" argument. */
+ ssl_ctx = SSL_CTX_new ((SSL_METHOD *)meth);
if (!ssl_ctx)
goto error;
+ /* OpenSSL ciphers: https://www.openssl.org/docs/apps/ciphers.html
+ * Since we want a good protection, we also use HIGH (that excludes MD4 ciphers and some more)
+ */
+ if (opt.secure_protocol == secure_protocol_pfs)
+ SSL_CTX_set_cipher_list (ssl_ctx, "HIGH:MEDIUM:!RC4:!SRP:!PSK:!RSA:!aNULL@STRENGTH");
+
SSL_CTX_set_default_verify_paths (ssl_ctx);
SSL_CTX_load_verify_locations (ssl_ctx, opt.ca_cert, opt.ca_directory);
- SSL_CTX_set_verify (ssl_ctx,
- opt.check_cert ? SSL_VERIFY_PEER : SSL_VERIFY_NONE,
- verify_callback);
+
+ /* SSL_VERIFY_NONE instructs OpenSSL not to abort SSL_connect if the
+ certificate is invalid. We verify the certificate separately in
+ ssl_check_certificate, which provides much better diagnostics
+ than examining the error stack after a failed SSL_connect. */
+ SSL_CTX_set_verify (ssl_ctx, SSL_VERIFY_NONE, NULL);
+
+ /* Use the private key from the cert file unless otherwise specified. */
+ if (opt.cert_file && !opt.private_key)
+ {
+ opt.private_key = opt.cert_file;
+ opt.private_key_type = opt.cert_type;
+ }
if (opt.cert_file)
if (SSL_CTX_use_certificate_file (ssl_ctx, opt.cert_file,
- key_type_to_ssl_type (opt.cert_type))
- != 1)
+ key_type_to_ssl_type (opt.cert_type))
+ != 1)
goto error;
if (opt.private_key)
if (SSL_CTX_use_PrivateKey_file (ssl_ctx, opt.private_key,
- key_type_to_ssl_type (opt.private_key_type))
- != 1)
+ key_type_to_ssl_type (opt.private_key_type))
+ != 1)
goto error;
- return 1;
+ /* Since fd_write unconditionally assumes partial writes (and
+ handles them correctly), allow them in OpenSSL. */
+ SSL_CTX_set_mode (ssl_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
+
+ /* The OpenSSL library can handle renegotiations automatically, so
+ tell it to do so. */
+ SSL_CTX_set_mode (ssl_ctx, SSL_MODE_AUTO_RETRY);
+
+ return true;
error:
if (ssl_ctx)
SSL_CTX_free (ssl_ctx);
print_errors ();
- return 0;
+ return false;
}
-static int
-openssl_read (int fd, char *buf, int bufsize, void *ctx)
+struct openssl_transport_context
+{
+ SSL *conn; /* SSL connection handle */
+ char *last_error; /* last error printed with openssl_errstr */
+};
+
+struct openssl_read_args
{
+ int fd;
+ struct openssl_transport_context *ctx;
+ char *buf;
+ int bufsize;
+ int retval;
+};
+
+static void openssl_read_callback(void *arg)
+{
+ struct openssl_read_args *args = (struct openssl_read_args *) arg;
+ struct openssl_transport_context *ctx = args->ctx;
+ SSL *conn = ctx->conn;
+ char *buf = args->buf;
+ int bufsize = args->bufsize;
int ret;
- SSL *ssl = (SSL *) ctx;
+
do
- ret = SSL_read (ssl, buf, bufsize);
- while (ret == -1
- && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
- && errno == EINTR);
- return ret;
+ ret = SSL_read (conn, buf, bufsize);
+ while (ret == -1 && SSL_get_error (conn, ret) == SSL_ERROR_SYSCALL
+ && errno == EINTR);
+ args->retval = ret;
+}
+
+static int
+openssl_read (int fd, char *buf, int bufsize, void *arg)
+{
+ struct openssl_read_args args;
+ args.fd = fd;
+ args.buf = buf;
+ args.bufsize = bufsize;
+ args.ctx = (struct openssl_transport_context*) arg;
+
+ if (run_with_timeout(opt.read_timeout, openssl_read_callback, &args)) {
+ return -1;
+ }
+ return args.retval;
}
static int
-openssl_write (int fd, char *buf, int bufsize, void *ctx)
+openssl_write (int fd _GL_UNUSED, char *buf, int bufsize, void *arg)
{
int ret = 0;
- SSL *ssl = (SSL *) ctx;
+ struct openssl_transport_context *ctx = arg;
+ SSL *conn = ctx->conn;
do
- ret = SSL_write (ssl, buf, bufsize);
+ ret = SSL_write (conn, buf, bufsize);
while (ret == -1
- && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
- && errno == EINTR);
+ && SSL_get_error (conn, ret) == SSL_ERROR_SYSCALL
+ && errno == EINTR);
return ret;
}
static int
-openssl_poll (int fd, double timeout, int wait_for, void *ctx)
+openssl_poll (int fd, double timeout, int wait_for, void *arg)
{
- SSL *ssl = (SSL *) ctx;
- if (timeout == 0)
+ struct openssl_transport_context *ctx = arg;
+ SSL *conn = ctx->conn;
+ if (SSL_pending (conn))
return 1;
- if (SSL_pending (ssl))
+ if (timeout == 0)
return 1;
return select_fd (fd, timeout, wait_for);
}
static int
-openssl_peek (int fd, char *buf, int bufsize, void *ctx)
+openssl_peek (int fd, char *buf, int bufsize, void *arg)
{
int ret;
- SSL *ssl = (SSL *) ctx;
+ struct openssl_transport_context *ctx = arg;
+ SSL *conn = ctx->conn;
+ if (! openssl_poll (fd, 0.0, WAIT_FOR_READ, arg))
+ return 0;
do
- ret = SSL_peek (ssl, buf, bufsize);
+ ret = SSL_peek (conn, buf, bufsize);
while (ret == -1
- && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
- && errno == EINTR);
+ && SSL_get_error (conn, ret) == SSL_ERROR_SYSCALL
+ && errno == EINTR);
return ret;
}
+static const char *
+openssl_errstr (int fd _GL_UNUSED, void *arg)
+{
+ struct openssl_transport_context *ctx = arg;
+ unsigned long errcode;
+ char *errmsg = NULL;
+ int msglen = 0;
+
+ /* If there are no SSL-specific errors, just return NULL. */
+ if ((errcode = ERR_get_error ()) == 0)
+ return NULL;
+
+ /* Get rid of previous contents of ctx->last_error, if any. */
+ xfree_null (ctx->last_error);
+
+ /* Iterate over OpenSSL's error stack and accumulate errors in the
+ last_error buffer, separated by "; ". This is better than using
+ a static buffer, which *always* takes up space (and has to be
+ large, to fit more than one error message), whereas these
+ allocations are only performed when there is an actual error. */
+
+ for (;;)
+ {
+ const char *str = ERR_error_string (errcode, NULL);
+ int len = strlen (str);
+
+ /* Allocate space for the existing message, plus two more chars
+ for the "; " separator and one for the terminating \0. */
+ errmsg = xrealloc (errmsg, msglen + len + 2 + 1);
+ memcpy (errmsg + msglen, str, len);
+ msglen += len;
+
+ /* Get next error and bail out if there are no more. */
+ errcode = ERR_get_error ();
+ if (errcode == 0)
+ break;
+
+ errmsg[msglen++] = ';';
+ errmsg[msglen++] = ' ';
+ }
+ errmsg[msglen] = '\0';
+
+ /* Store the error in ctx->last_error where openssl_close will
+ eventually find it and free it. */
+ ctx->last_error = errmsg;
+
+ return errmsg;
+}
+
static void
-openssl_close (int fd, void *ctx)
+openssl_close (int fd, void *arg)
{
- SSL *ssl = (SSL *) ctx;
- SSL_shutdown (ssl);
- SSL_free (ssl);
+ struct openssl_transport_context *ctx = arg;
+ SSL *conn = ctx->conn;
+
+ SSL_shutdown (conn);
+ SSL_free (conn);
+ xfree_null (ctx->last_error);
+ xfree (ctx);
-#ifdef WINDOWS
- closesocket (fd);
-#else
close (fd);
-#endif
- DEBUGP (("Closed %d/SSL 0x%0lx\n", fd, (unsigned long) ssl));
+ DEBUGP (("Closed %d/SSL 0x%0*lx\n", fd, PTR_FORMAT (conn)));
}
-/* Sets up a SSL structure and performs the handshake on fd. The
- resulting SSL structure is registered with the file descriptor FD
- using fd_register_transport. That way subsequent calls to xread,
- xwrite, etc., will use the appropriate SSL functions.
+/* openssl_transport is the singleton that describes the SSL transport
+ methods provided by this file. */
- Returns 1 on success, 0 on failure. */
+static struct transport_implementation openssl_transport = {
+ openssl_read, openssl_write, openssl_poll,
+ openssl_peek, openssl_errstr, openssl_close
+};
-int
-ssl_connect (int fd)
+struct scwt_context
{
SSL *ssl;
+ int result;
+};
+
+static void
+ssl_connect_with_timeout_callback(void *arg)
+{
+ struct scwt_context *ctx = (struct scwt_context *)arg;
+ ctx->result = SSL_connect(ctx->ssl);
+}
+
+/* Perform the SSL handshake on file descriptor FD, which is assumed
+ to be connected to an SSL server. The SSL handle provided by
+ OpenSSL is registered with the file descriptor FD using
+ fd_register_transport, so that subsequent calls to fd_read,
+ fd_write, etc., will use the corresponding SSL functions.
+
+ Returns true on success, false on failure. */
+
+bool
+ssl_connect_wget (int fd, const char *hostname)
+{
+ SSL *conn;
+ struct scwt_context scwt_ctx;
+ struct openssl_transport_context *ctx;
+
+ DEBUGP (("Initiating SSL handshake.\n"));
assert (ssl_ctx != NULL);
- ssl = SSL_new (ssl_ctx);
- if (!ssl)
- goto err;
- if (!SSL_set_fd (ssl, fd))
- goto err;
- SSL_set_connect_state (ssl);
- if (SSL_connect (ssl) <= 0 || ssl->state != SSL_ST_OK)
- goto err;
-
- /* Register FD with Wget's transport layer, i.e. arrange that
- SSL-enabled functions are used for reading, writing, and polling.
- That way the rest of Wget can keep using fd_read, fd_write, and
- friends and not care what happens underneath. */
- fd_register_transport (fd, openssl_read, openssl_write, openssl_poll,
- openssl_peek, openssl_close, ssl);
- DEBUGP (("Connected %d to SSL 0x%0*lx\n", fd, 2 * sizeof (void *),
- (unsigned long) ssl));
- return 1;
-
- err:
+ conn = SSL_new (ssl_ctx);
+ if (!conn)
+ goto error;
+#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
+ /* If the SSL library was build with support for ServerNameIndication
+ then use it whenever we have a hostname. If not, don't, ever. */
+ if (! is_valid_ip_address (hostname))
+ {
+ if (! SSL_set_tlsext_host_name (conn, hostname))
+ {
+ DEBUGP (("Failed to set TLS server-name indication."));
+ goto error;
+ }
+ }
+#endif
+
+#ifndef FD_TO_SOCKET
+# define FD_TO_SOCKET(X) (X)
+#endif
+ if (!SSL_set_fd (conn, FD_TO_SOCKET (fd)))
+ goto error;
+ SSL_set_connect_state (conn);
+
+ scwt_ctx.ssl = conn;
+ if (run_with_timeout(opt.read_timeout, ssl_connect_with_timeout_callback,
+ &scwt_ctx)) {
+ DEBUGP (("SSL handshake timed out.\n"));
+ goto timeout;
+ }
+ if (scwt_ctx.result <= 0 || conn->state != SSL_ST_OK)
+ goto error;
+
+ ctx = xnew0 (struct openssl_transport_context);
+ ctx->conn = conn;
+
+ /* Register FD with Wget's transport layer, i.e. arrange that our
+ functions are used for reading, writing, and polling. */
+ fd_register_transport (fd, &openssl_transport, ctx);
+ DEBUGP (("Handshake successful; connected socket %d to SSL handle 0x%0*lx\n",
+ fd, PTR_FORMAT (conn)));
+ return true;
+
+ error:
+ DEBUGP (("SSL handshake failed.\n"));
print_errors ();
- if (ssl)
- SSL_free (ssl);
- return 0;
+ timeout:
+ if (conn)
+ SSL_free (conn);
+ return false;
+}
+
+#define ASTERISK_EXCLUDES_DOT /* mandated by rfc2818 */
+
+/* Return true is STRING (case-insensitively) matches PATTERN, false
+ otherwise. The recognized wildcard character is "*", which matches
+ any character in STRING except ".". Any number of the "*" wildcard
+ may be present in the pattern.
+
+ This is used to match of hosts as indicated in rfc2818: "Names may
+ contain the wildcard character * which is considered to match any
+ single domain name component or component fragment. E.g., *.a.com
+ matches foo.a.com but not bar.foo.a.com. f*.com matches foo.com but
+ not bar.com [or foo.bar.com]."
+
+ If the pattern contain no wildcards, pattern_match(a, b) is
+ equivalent to !strcasecmp(a, b). */
+
+static bool
+pattern_match (const char *pattern, const char *string)
+{
+ const char *p = pattern, *n = string;
+ char c;
+ for (; (c = c_tolower (*p++)) != '\0'; n++)
+ if (c == '*')
+ {
+ for (c = c_tolower (*p); c == '*'; c = c_tolower (*++p))
+ ;
+ for (; *n != '\0'; n++)
+ if (c_tolower (*n) == c && pattern_match (p, n))
+ return true;
+#ifdef ASTERISK_EXCLUDES_DOT
+ else if (*n == '.')
+ return false;
+#endif
+ return c == '\0';
+ }
+ else
+ {
+ if (c != c_tolower (*n))
+ return false;
+ }
+ return *n == '\0';
}
+
+/* Verify the validity of the certificate presented by the server.
+ Also check that the "common name" of the server, as presented by
+ its certificate, corresponds to HOST. (HOST typically comes from
+ the URL and is what the user thinks he's connecting to.)
+
+ This assumes that ssl_connect_wget has successfully finished, i.e. that
+ the SSL handshake has been performed and that FD is connected to an
+ SSL handle.
+
+ If opt.check_cert is true (the default), this returns 1 if the
+ certificate is valid, 0 otherwise. If opt.check_cert is 0, the
+ function always returns 1, but should still be called because it
+ warns the user about any problems with the certificate. */
+
+bool
+ssl_check_certificate (int fd, const char *host)
+{
+ X509 *cert;
+ GENERAL_NAMES *subjectAltNames;
+ char common_name[256];
+ long vresult;
+ bool success = true;
+ bool alt_name_checked = false;
+
+ /* If the user has specified --no-check-cert, we still want to warn
+ him about problems with the server's certificate. */
+ const char *severity = opt.check_cert ? _("ERROR") : _("WARNING");
+
+ struct openssl_transport_context *ctx = fd_transport_context (fd);
+ SSL *conn = ctx->conn;
+ assert (conn != NULL);
+
+ cert = SSL_get_peer_certificate (conn);
+ if (!cert)
+ {
+ logprintf (LOG_NOTQUIET, _("%s: No certificate presented by %s.\n"),
+ severity, quotearg_style (escape_quoting_style, host));
+ success = false;
+ goto no_cert; /* must bail out since CERT is NULL */
+ }
+
+ IF_DEBUG
+ {
+ char *subject = X509_NAME_oneline (X509_get_subject_name (cert), 0, 0);
+ char *issuer = X509_NAME_oneline (X509_get_issuer_name (cert), 0, 0);
+ DEBUGP (("certificate:\n subject: %s\n issuer: %s\n",
+ quotearg_n_style (0, escape_quoting_style, subject),
+ quotearg_n_style (1, escape_quoting_style, issuer)));
+ OPENSSL_free (subject);
+ OPENSSL_free (issuer);
+ }
+
+ vresult = SSL_get_verify_result (conn);
+ if (vresult != X509_V_OK)
+ {
+ char *issuer = X509_NAME_oneline (X509_get_issuer_name (cert), 0, 0);
+ logprintf (LOG_NOTQUIET,
+ _("%s: cannot verify %s's certificate, issued by %s:\n"),
+ severity, quotearg_n_style (0, escape_quoting_style, host),
+ quote_n (1, issuer));
+ /* Try to print more user-friendly (and translated) messages for
+ the frequent verification errors. */
+ switch (vresult)
+ {
+ case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
+ logprintf (LOG_NOTQUIET,
+ _(" Unable to locally verify the issuer's authority.\n"));
+ break;
+ case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
+ case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
+ logprintf (LOG_NOTQUIET,
+ _(" Self-signed certificate encountered.\n"));
+ break;
+ case X509_V_ERR_CERT_NOT_YET_VALID:
+ logprintf (LOG_NOTQUIET, _(" Issued certificate not yet valid.\n"));
+ break;
+ case X509_V_ERR_CERT_HAS_EXPIRED:
+ logprintf (LOG_NOTQUIET, _(" Issued certificate has expired.\n"));
+ break;
+ default:
+ /* For the less frequent error strings, simply provide the
+ OpenSSL error message. */
+ logprintf (LOG_NOTQUIET, " %s\n",
+ X509_verify_cert_error_string (vresult));
+ }
+ success = false;
+ /* Fall through, so that the user is warned about *all* issues
+ with the cert (important with --no-check-certificate.) */
+ }
+
+ /* Check that HOST matches the common name in the certificate.
+ #### The following remains to be done:
+
+ - When matching against common names, it should loop over all
+ common names and choose the most specific one, i.e. the last
+ one, not the first one, which the current code picks.
+
+ - Ensure that ASN1 strings from the certificate are encoded as
+ UTF-8 which can be meaningfully compared to HOST. */
+
+ subjectAltNames = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
+
+ if (subjectAltNames)
+ {
+ /* Test subject alternative names */
+
+ /* Do we want to check for dNSNAmes or ipAddresses (see RFC 2818)?
+ * Signal it by host_in_octet_string. */
+ ASN1_OCTET_STRING *host_in_octet_string = a2i_IPADDRESS (host);
+
+ int numaltnames = sk_GENERAL_NAME_num (subjectAltNames);
+ int i;
+ for (i=0; i < numaltnames; i++)
+ {
+ const GENERAL_NAME *name =
+ sk_GENERAL_NAME_value (subjectAltNames, i);
+ if (name)
+ {
+ if (host_in_octet_string)
+ {
+ if (name->type == GEN_IPADD)
+ {
+ /* Check for ipAddress */
+ /* TODO: Should we convert between IPv4-mapped IPv6
+ * addresses and IPv4 addresses? */
+ alt_name_checked = true;
+ if (!ASN1_STRING_cmp (host_in_octet_string,
+ name->d.iPAddress))
+ break;
+ }
+ }
+ else if (name->type == GEN_DNS)
+ {
+ /* dNSName should be IA5String (i.e. ASCII), however who
+ * does trust CA? Convert it into UTF-8 for sure. */
+ unsigned char *name_in_utf8 = NULL;
+
+ /* Check for dNSName */
+ alt_name_checked = true;
+
+ if (0 <= ASN1_STRING_to_UTF8 (&name_in_utf8, name->d.dNSName))
+ {
+ /* Compare and check for NULL attack in ASN1_STRING */
+ if (pattern_match ((char *)name_in_utf8, host) &&
+ (strlen ((char *)name_in_utf8) ==
+ (size_t) ASN1_STRING_length (name->d.dNSName)))
+ {
+ OPENSSL_free (name_in_utf8);
+ break;
+ }
+ OPENSSL_free (name_in_utf8);
+ }
+ }
+ }
+ }
+ sk_GENERAL_NAME_free (subjectAltNames);
+ if (host_in_octet_string)
+ ASN1_OCTET_STRING_free(host_in_octet_string);
+
+ if (alt_name_checked == true && i >= numaltnames)
+ {
+ logprintf (LOG_NOTQUIET,
+ _("%s: no certificate subject alternative name matches\n"
+ "\trequested host name %s.\n"),
+ severity, quote_n (1, host));
+ success = false;
+ }
+ }
+
+ if (alt_name_checked == false)
+ {
+ /* Test commomName */
+ X509_NAME *xname = X509_get_subject_name(cert);
+ common_name[0] = '\0';
+ X509_NAME_get_text_by_NID (xname, NID_commonName, common_name,
+ sizeof (common_name));
+
+ if (!pattern_match (common_name, host))
+ {
+ logprintf (LOG_NOTQUIET, _("\
+ %s: certificate common name %s doesn't match requested host name %s.\n"),
+ severity, quote_n (0, common_name), quote_n (1, host));
+ success = false;
+ }
+ else
+ {
+ /* We now determine the length of the ASN1 string. If it
+ * differs from common_name's length, then there is a \0
+ * before the string terminates. This can be an instance of a
+ * null-prefix attack.
+ *
+ * https://www.blackhat.com/html/bh-usa-09/bh-usa-09-archives.html#Marlinspike
+ * */
+
+ int i = -1, j;
+ X509_NAME_ENTRY *xentry;
+ ASN1_STRING *sdata;
+
+ if (xname) {
+ for (;;)
+ {
+ j = X509_NAME_get_index_by_NID (xname, NID_commonName, i);
+ if (j == -1) break;
+ i = j;
+ }
+ }
+
+ xentry = X509_NAME_get_entry(xname,i);
+ sdata = X509_NAME_ENTRY_get_data(xentry);
+ if (strlen (common_name) != (size_t) ASN1_STRING_length (sdata))
+ {
+ logprintf (LOG_NOTQUIET, _("\
+ %s: certificate common name is invalid (contains a NUL character).\n\
+ This may be an indication that the host is not who it claims to be\n\
+ (that is, it is not the real %s).\n"),
+ severity, quote (host));
+ success = false;
+ }
+ }
+ }
+
+
+ if (success)
+ DEBUGP (("X509 certificate successfully verified and matches host %s\n",
+ quotearg_style (escape_quoting_style, host)));
+ X509_free (cert);
+
+ no_cert:
+ if (opt.check_cert && !success)
+ logprintf (LOG_NOTQUIET, _("\
+To connect to %s insecurely, use `--no-check-certificate'.\n"),
+ quotearg_style (escape_quoting_style, host));
+
+ /* Allow --no-check-cert to disable certificate checking. */
+ return opt.check_cert ? success : true;
+}
+
+/*
+ * vim: tabstop=2 shiftwidth=2 softtabstop=2
+ */