+/* SSL support via OpenSSL library.
+ Copyright (C) 2000-2005 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
+(at your option) any later version.
+
+GNU Wget 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 Wget; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+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. */
+
+#include <config.h>
+
+#include <assert.h>
+#include <errno.h>
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#ifdef HAVE_STRING_H
+# include <string.h>
+#else
+# include <strings.h>
+#endif
+
+#include <openssl/bio.h>
+#include <openssl/crypto.h>
+#include <openssl/x509.h>
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#include <openssl/rand.h>
+
+#include "wget.h"
+#include "utils.h"
+#include "connect.h"
+#include "url.h"
+#include "ssl.h"
+
+#ifndef errno
+extern int errno;
+#endif
+
+SSL_CTX *ssl_ctx;
+
+static void
+ssl_init_prng (void)
+{
+ /* It is likely that older versions of OpenSSL will fail on
+ non-Linux machines because this code is unable to seed the PRNG
+ on older versions of the library. */
+
+#if SSLEAY_VERSION_NUMBER >= 0x00905100
+ char rand_file[256];
+
+ /* First, seed from a file specified by the user. This will be
+ $RANDFILE, if set, or ~/.rnd. */
+ RAND_file_name (rand_file, sizeof (rand_file));
+ if (rand_file)
+ /* Seed at most 16k (value borrowed from curl) from random file. */
+ RAND_load_file (rand_file, 16384);
+
+ if (RAND_status ())
+ return;
+
+ /* Get random data from EGD if opt.egd_file was set. */
+ if (opt.egd_file && *opt.egd_file)
+ RAND_egd (opt.egd_file);
+
+ if (RAND_status ())
+ return;
+
+#ifdef WINDOWS
+ /* Under Windows, we can try to seed the PRNG using screen content.
+ This may or may not work, depending on whether we'll calling Wget
+ interactively. */
+
+ RAND_screen ();
+ if (RAND_status ())
+ return;
+#endif
+
+#if 0 /* don't do this by default */
+ {
+ int maxrand = 500;
+
+ /* Still not random enough, presumably because neither /dev/random
+ nor EGD were available. Try to seed OpenSSL's PRNG with libc
+ PRNG. This is cryptographically weak and defeats the purpose
+ of using OpenSSL, which is why it is highly discouraged. */
+
+ logprintf (LOG_VERBOSE, _("WARNING: using a weak random seed.\n"));
+
+ while (RAND_status () == 0 && maxrand-- > 0)
+ {
+ unsigned char rnd = random_number (256);
+ RAND_seed (&rnd, sizeof (rnd));
+ }
+ }
+#endif
+
+#endif /* SSLEAY_VERSION_NUMBER >= 0x00905100 */
+}
+
+static int
+verify_callback (int ok, X509_STORE_CTX *ctx)
+{
+ char *s, buf[256];
+ s = 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 SSL errors. */
+
+static void
+ssl_print_errors (void)
+{
+ unsigned long curerr = 0;
+ while ((curerr = ERR_get_error ()) != 0)
+ logprintf (LOG_NOTQUIET, "OpenSSL: %s\n", ERR_error_string (curerr, NULL));
+}
+
+/* Creates a SSL Context and sets some defaults for it */
+uerr_t
+ssl_init ()
+{
+ SSL_METHOD *meth = NULL;
+
+ if (ssl_ctx)
+ return 0;
+
+ /* Init the PRNG. If that fails, bail out. */
+ ssl_init_prng ();
+ if (RAND_status () == 0)
+ {
+ logprintf (LOG_NOTQUIET,
+ _("Could not seed OpenSSL PRNG; disabling SSL.\n"));
+ scheme_disable (SCHEME_HTTPS);
+ return SSLERRCTXCREATE;
+ }
+
+ SSL_library_init ();
+ SSL_load_error_strings ();
+ SSLeay_add_all_algorithms ();
+ SSLeay_add_ssl_algorithms ();
+ switch (opt.secure_protocol)
+ {
+ case secure_protocol_auto:
+ meth = SSLv23_client_method ();
+ break;
+ case secure_protocol_sslv2:
+ meth = SSLv2_client_method ();
+ break;
+ case secure_protocol_sslv3:
+ meth = SSLv3_client_method ();
+ break;
+ case secure_protocol_tlsv1:
+ meth = TLSv1_client_method ();
+ break;
+ }
+ if (meth == NULL)
+ {
+ ssl_print_errors ();
+ return SSLERRCTXCREATE;
+ }
+
+ ssl_ctx = SSL_CTX_new (meth);
+ if (meth == NULL)
+ {
+ ssl_print_errors ();
+ return SSLERRCTXCREATE;
+ }
+
+ 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);
+
+ if (opt.cert_file != NULL || opt.cert_key != NULL)
+ {
+ int ssl_cert_type = SSL_FILETYPE_PEM;
+ switch (opt.cert_type)
+ {
+ case cert_type_pem:
+ ssl_cert_type = SSL_FILETYPE_PEM;
+ break;
+ case cert_type_asn1:
+ ssl_cert_type = SSL_FILETYPE_ASN1;
+ break;
+ }
+
+#if 0 /* what was this supposed to achieve? */
+ if (opt.cert_key == NULL)
+ opt.cert_key = opt.cert_file;
+ if (opt.cert_file == NULL)
+ opt.cert_file = opt.cert_key;
+#endif
+
+ if (SSL_CTX_use_certificate_file (ssl_ctx, opt.cert_file,
+ ssl_cert_type) != 1)
+ {
+ ssl_print_errors ();
+ return SSLERRCERTFILE;
+ }
+ if (SSL_CTX_use_PrivateKey_file (ssl_ctx, opt.cert_key,
+ ssl_cert_type) != 1)
+ {
+ ssl_print_errors ();
+ return SSLERRCERTKEY;
+ }
+ }
+
+ return 0; /* Succeded */
+}
+
+static int
+ssl_read (int fd, char *buf, int bufsize, void *ctx)
+{
+ 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;
+}
+
+static int
+ssl_write (int fd, char *buf, int bufsize, void *ctx)
+{
+ int ret = 0;
+ SSL *ssl = (SSL *) ctx;
+ do
+ ret = SSL_write (ssl, buf, bufsize);
+ while (ret == -1
+ && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
+ && errno == EINTR);
+ return ret;
+}
+
+static int
+ssl_poll (int fd, double timeout, int wait_for, void *ctx)
+{
+ SSL *ssl = (SSL *) ctx;
+ if (timeout == 0)
+ return 1;
+ if (SSL_pending (ssl))
+ return 1;
+ return select_fd (fd, timeout, wait_for);
+}
+
+static int
+ssl_peek (int fd, char *buf, int bufsize, void *ctx)
+{
+ int ret;
+ SSL *ssl = (SSL *) ctx;
+ do
+ ret = SSL_peek (ssl, buf, bufsize);
+ while (ret == -1
+ && SSL_get_error (ssl, ret) == SSL_ERROR_SYSCALL
+ && errno == EINTR);
+ return ret;
+}
+
+static void
+ssl_close (int fd, void *ctx)
+{
+ SSL *ssl = (SSL *) ctx;
+ SSL_shutdown (ssl);
+ SSL_free (ssl);
+
+#ifdef WINDOWS
+ closesocket (fd);
+#else
+ close (fd);
+#endif
+
+ DEBUGP (("Closed %d/SSL 0x%0lx\n", fd, (unsigned long) ssl));
+}
+
+/* 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.
+
+ Returns 1 on success, 0 on failure. */
+
+int
+ssl_connect (int fd)
+{
+ SSL *ssl;
+
+ 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 xread, xwrite, and
+ friends and not care what happens underneath. */
+ fd_register_transport (fd, ssl_read, ssl_write, ssl_poll, ssl_peek,
+ ssl_close, ssl);
+ DEBUGP (("Connected %d to SSL 0x%0*lx\n", fd, 2 * sizeof (void *),
+ (unsigned long) ssl));
+ return 1;
+
+ err:
+ ssl_print_errors ();
+ if (ssl)
+ SSL_free (ssl);
+ return 0;
+}