1 /* SSL support via OpenSSL library.
2 Copyright (C) 2000-2005 Free Software Foundation, Inc.
3 Originally contributed by Christian Fraenkel.
5 This file is part of GNU Wget.
7 GNU Wget is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 GNU Wget is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with Wget; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 In addition, as a special exception, the Free Software Foundation
22 gives permission to link the code of its release of Wget with the
23 OpenSSL project's "OpenSSL" library (or with modified versions of it
24 that use the same license as the "OpenSSL" library), and distribute
25 the linked executables. You must obey the GNU General Public License
26 in all respects for all of the code used other than "OpenSSL". If you
27 modify this file, you may extend this exception to your version of the
28 file, but you are not obligated to do so. If you do not wish to do
29 so, delete this exception statement from your version. */
44 #include <openssl/bio.h>
45 #include <openssl/crypto.h>
46 #include <openssl/x509.h>
47 #include <openssl/ssl.h>
48 #include <openssl/err.h>
49 #include <openssl/pem.h>
50 #include <openssl/rand.h>
62 /* Application-wide SSL context. This is common to all SSL
66 /* Initialize the SSL's PRNG using various methods. */
72 const char *random_file;
75 /* The PRNG has been seeded; no further action is necessary. */
78 /* Seed from a file specified by the user. This will be the file
79 specified with --random-file, $RANDFILE, if set, or ~/.rnd, if it
82 random_file = opt.random_file;
85 /* Get the random file name using RAND_file_name. */
87 random_file = RAND_file_name (namebuf, sizeof (namebuf));
90 if (random_file && *random_file)
91 /* Seed at most 16k (apparently arbitrary value borrowed from
92 curl) from random file. */
93 RAND_load_file (random_file, 16384);
98 /* Get random data from EGD if opt.egd_file was used. */
99 if (opt.egd_file && *opt.egd_file)
100 RAND_egd (opt.egd_file);
106 /* Under Windows, we can try to seed the PRNG using screen content.
107 This may or may not work, depending on whether we'll calling Wget
115 #if 0 /* don't do this by default */
119 /* Still not random enough, presumably because neither /dev/random
120 nor EGD were available. Try to seed OpenSSL's PRNG with libc
121 PRNG. This is cryptographically weak and defeats the purpose
122 of using OpenSSL, which is why it is highly discouraged. */
124 logprintf (LOG_NOTQUIET, _("WARNING: using a weak random seed.\n"));
126 while (RAND_status () == 0 && maxrand-- > 0)
128 unsigned char rnd = random_number (256);
129 RAND_seed (&rnd, sizeof (rnd));
135 /* #### Someone should audit and document this. */
138 verify_callback (int ok, X509_STORE_CTX *ctx)
141 /* #### Why are we not using the result of this call? */
142 X509_NAME_oneline (X509_get_subject_name (ctx->current_cert),
148 case X509_V_ERR_CERT_NOT_YET_VALID:
149 case X509_V_ERR_CERT_HAS_EXPIRED:
150 /* This mean the CERT is not valid !!! */
153 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
154 /* Unsure if we should handle that this way */
162 /* Print errors in the OpenSSL error stack. */
167 unsigned long curerr = 0;
168 while ((curerr = ERR_get_error ()) != 0)
169 logprintf (LOG_NOTQUIET, "OpenSSL: %s\n", ERR_error_string (curerr, NULL));
172 /* Convert keyfile type as used by options.h to a type as accepted by
173 SSL_CTX_use_certificate_file and SSL_CTX_use_PrivateKey_file.
175 (options.h intentionally doesn't use values from openssl/ssl.h so
176 it doesn't depend specifically on OpenSSL for SSL functionality.) */
179 key_type_to_ssl_type (enum keyfile_type type)
184 return SSL_FILETYPE_PEM;
186 return SSL_FILETYPE_ASN1;
192 /* Create an SSL Context and set default paths etc. Called the first
193 time an HTTP download is attempted.
195 Returns 0 on success, non-zero otherwise. */
203 /* The SSL has already been initialized. */
206 /* Init the PRNG. If that fails, bail out. */
208 if (RAND_status () != 1)
210 logprintf (LOG_NOTQUIET,
211 _("Could not seed PRNG; consider using --random-file.\n"));
216 SSL_load_error_strings ();
217 SSLeay_add_all_algorithms ();
218 SSLeay_add_ssl_algorithms ();
220 switch (opt.secure_protocol)
222 case secure_protocol_auto:
223 meth = SSLv23_client_method ();
225 case secure_protocol_sslv2:
226 meth = SSLv2_client_method ();
228 case secure_protocol_sslv3:
229 meth = SSLv3_client_method ();
231 case secure_protocol_tlsv1:
232 meth = TLSv1_client_method ();
238 ssl_ctx = SSL_CTX_new (meth);
242 SSL_CTX_set_default_verify_paths (ssl_ctx);
243 SSL_CTX_load_verify_locations (ssl_ctx, opt.ca_cert, opt.ca_directory);
244 SSL_CTX_set_verify (ssl_ctx,
245 opt.check_cert ? SSL_VERIFY_PEER : SSL_VERIFY_NONE,
249 if (SSL_CTX_use_certificate_file (ssl_ctx, opt.cert_file,
250 key_type_to_ssl_type (opt.cert_type))
254 if (SSL_CTX_use_PrivateKey_file (ssl_ctx, opt.private_key,
255 key_type_to_ssl_type (opt.private_key_type))
263 SSL_CTX_free (ssl_ctx);
269 openssl_read (int fd, char *buf, int bufsize, void *ctx)
272 SSL *ssl = (SSL *) ctx;
274 ret = SSL_read (ssl, buf, bufsize);
276 && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
282 openssl_write (int fd, char *buf, int bufsize, void *ctx)
285 SSL *ssl = (SSL *) ctx;
287 ret = SSL_write (ssl, buf, bufsize);
289 && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
295 openssl_poll (int fd, double timeout, int wait_for, void *ctx)
297 SSL *ssl = (SSL *) ctx;
300 if (SSL_pending (ssl))
302 return select_fd (fd, timeout, wait_for);
306 openssl_peek (int fd, char *buf, int bufsize, void *ctx)
309 SSL *ssl = (SSL *) ctx;
311 ret = SSL_peek (ssl, buf, bufsize);
313 && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
319 openssl_close (int fd, void *ctx)
321 SSL *ssl = (SSL *) ctx;
331 DEBUGP (("Closed %d/SSL 0x%0lx\n", fd, (unsigned long) ssl));
334 /* Sets up a SSL structure and performs the handshake on fd. The
335 resulting SSL structure is registered with the file descriptor FD
336 using fd_register_transport. That way subsequent calls to xread,
337 xwrite, etc., will use the appropriate SSL functions.
339 Returns 1 on success, 0 on failure. */
346 assert (ssl_ctx != NULL);
347 ssl = SSL_new (ssl_ctx);
350 if (!SSL_set_fd (ssl, fd))
352 SSL_set_connect_state (ssl);
353 if (SSL_connect (ssl) <= 0 || ssl->state != SSL_ST_OK)
356 /* Register FD with Wget's transport layer, i.e. arrange that
357 SSL-enabled functions are used for reading, writing, and polling.
358 That way the rest of Wget can keep using fd_read, fd_write, and
359 friends and not care what happens underneath. */
360 fd_register_transport (fd, openssl_read, openssl_write, openssl_poll,
361 openssl_peek, openssl_close, ssl);
362 DEBUGP (("Connected %d to SSL 0x%0*lx\n", fd, 2 * sizeof (void *),
363 (unsigned long) ssl));