X-Git-Url: http://sjero.net/git/?p=wget;a=blobdiff_plain;f=src%2Fopenssl.c;h=b55ca8bfb5add32195151d9b35b6b1ce41414ad7;hp=f617f79b4eb51ecbedf18cb53d70c4fddf1bfbd9;hb=34b1a7ad5d8d09cb9c9c8015b09a1298c301321c;hpb=debec8216fc7126c80a322edb3acbaa1287ae6b7 diff --git a/src/openssl.c b/src/openssl.c index f617f79b..b55ca8bf 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 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, @@ -15,20 +16,20 @@ 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., -51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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 @@ -42,7 +43,6 @@ so, delete this exception statement from your version. */ #include #include -#include "wget.h" #include "utils.h" #include "connect.h" #include "url.h" @@ -114,8 +114,8 @@ 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 @@ -124,7 +124,7 @@ init_prng (void) /* Print errors in the OpenSSL error stack. */ static void -print_errors (void) +print_errors (void) { unsigned long err; while ((err = ERR_get_error ()) != 0) @@ -170,7 +170,7 @@ ssl_init () 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; } @@ -210,21 +210,32 @@ ssl_init () 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; /* 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: @@ -234,104 +245,132 @@ ssl_init () return false; } +struct openssl_transport_context { + SSL *conn; /* SSL connection handle */ + char *last_error; /* last error printed with openssl_errstr */ +}; + static int -openssl_read (int fd, char *buf, int bufsize, void *ctx) +openssl_read (int fd, char *buf, int bufsize, void *arg) { int ret; - SSL *ssl = ctx; + struct openssl_transport_context *ctx = arg; + SSL *conn = ctx->conn; do - ret = SSL_read (ssl, buf, bufsize); + ret = SSL_read (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_write (int fd, char *buf, int bufsize, void *ctx) +openssl_write (int fd, char *buf, int bufsize, void *arg) { int ret = 0; - 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 = ctx; + struct openssl_transport_context *ctx = arg; + SSL *conn = ctx->conn; if (timeout == 0) return 1; - if (SSL_pending (ssl)) + if (SSL_pending (conn)) 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 = ctx; + struct openssl_transport_context *ctx = arg; + SSL *conn = ctx->conn; 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, void *ctx) +openssl_errstr (int fd, void *arg) { - /* Unfortunately we cannot use ERR_error_string's internal buffer - because we must be prepared to print more than one error. */ - static char errbuf[512]; - char *p = errbuf, *end = errbuf + sizeof errbuf; - unsigned long err; + struct openssl_transport_context *ctx = arg; + unsigned long errcode; + char *errmsg = NULL; + int msglen = 0; - if ((err = ERR_get_error ()) == 0) - /* Inform the caller that there have been no errors */ + /* If there are no SSL-specific errors, just return NULL. */ + if ((errcode = ERR_get_error ()) == 0) return NULL; - /* Iterate over OpenSSL's error stack and print errors to ERRBUF, - separated by "; ", while being careful not to overrun ERRBUF. */ - do + /* 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 (;;) { - ERR_error_string_n (err, p, end - p); - p = strchr (p, '\0'); - err = ERR_get_error (); - if (err == 0) - break; - if (p < end) *p++ = ';'; - if (p < end) *p++ = ' '; + 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++] = ' '; } - while (p < end); + errmsg[msglen] = '\0'; - if (p < end) - *p++ = '\0'; - else - end[-1] = '\0'; - return errbuf; + /* 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 = ctx; - SSL_shutdown (ssl); - SSL_free (ssl); + struct openssl_transport_context *ctx = arg; + SSL *conn = ctx->conn; -#ifdef WINDOWS + SSL_shutdown (conn); + SSL_free (conn); + xfree_null (ctx->last_error); + xfree (ctx); + +#if defined(WINDOWS) || defined(USE_WATT32) 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))); } /* openssl_transport is the singleton that describes the SSL transport @@ -351,38 +390,42 @@ static struct transport_implementation openssl_transport = { Returns true on success, false on failure. */ bool -ssl_connect (int fd) +ssl_connect_wget (int fd) { - SSL *ssl; + SSL *conn; + struct openssl_transport_context *ctx; DEBUGP (("Initiating SSL handshake.\n")); assert (ssl_ctx != NULL); - ssl = SSL_new (ssl_ctx); - if (!ssl) + conn = SSL_new (ssl_ctx); + if (!conn) goto error; - if (!SSL_set_fd (ssl, fd)) + if (!SSL_set_fd (conn, fd)) goto error; - SSL_set_connect_state (ssl); - if (SSL_connect (ssl) <= 0 || ssl->state != SSL_ST_OK) + SSL_set_connect_state (conn); + if (SSL_connect (conn) <= 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, ssl); + fd_register_transport (fd, &openssl_transport, ctx); DEBUGP (("Handshake successful; connected socket %d to SSL handle 0x%0*lx\n", - fd, PTR_FORMAT (ssl))); + fd, PTR_FORMAT (conn))); return true; error: DEBUGP (("SSL handshake failed.\n")); print_errors (); - if (ssl) - SSL_free (ssl); + if (conn) + SSL_free (conn); return false; } -#define ASTERISK_EXCLUDES_DOT /* mandated by rfc2818 */ +#define ASTERISK_EXCLUDES_DOT /* mandated by rfc2818 */ /* Return true is STRING (case-insensitively) matches PATTERN, false otherwise. The recognized wildcard character is "*", which matches @@ -403,24 +446,24 @@ pattern_match (const char *pattern, const char *string) { const char *p = pattern, *n = string; char c; - for (; (c = TOLOWER (*p++)) != '\0'; n++) + for (; (c = c_tolower (*p++)) != '\0'; n++) if (c == '*') { - for (c = TOLOWER (*p); c == '*'; c = TOLOWER (*++p)) - ; - for (; *n != '\0'; n++) - if (TOLOWER (*n) == c && pattern_match (p, n)) - return true; + 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; + else if (*n == '.') + return false; #endif - return c == '\0'; + return c == '\0'; } else { - if (c != TOLOWER (*n)) - return false; + if (c != c_tolower (*n)) + return false; } return *n == '\0'; } @@ -430,7 +473,7 @@ pattern_match (const char *pattern, const char *string) 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 has successfully finished, i.e. that + 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. @@ -451,16 +494,17 @@ ssl_check_certificate (int fd, const char *host) him about problems with the server's certificate. */ const char *severity = opt.check_cert ? _("ERROR") : _("WARNING"); - SSL *ssl = (SSL *) fd_transport_context (fd); - assert (ssl != NULL); + struct openssl_transport_context *ctx = fd_transport_context (fd); + SSL *conn = ctx->conn; + assert (conn != NULL); - cert = SSL_get_peer_certificate (ssl); + cert = SSL_get_peer_certificate (conn); if (!cert) { logprintf (LOG_NOTQUIET, _("%s: No certificate presented by %s.\n"), - severity, escnonprint (host)); + severity, quotearg_style (escape_quoting_style, host)); success = false; - goto no_cert; /* must bail out since CERT is NULL */ + goto no_cert; /* must bail out since CERT is NULL */ } IF_DEBUG @@ -468,30 +512,47 @@ ssl_check_certificate (int fd, const char *host) 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", - escnonprint (subject), escnonprint (issuer))); + 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 (ssl); + vresult = SSL_get_verify_result (conn); if (vresult != X509_V_OK) { - /* #### We might want to print saner (and translatable) error - messages for several frequently encountered errors. The - candidates would include - X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY, - X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN, - X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT, - X509_V_ERR_CERT_NOT_YET_VALID, X509_V_ERR_CERT_HAS_EXPIRED, - and possibly others. The current approach would still be - used for the less frequent failure cases. */ + char *issuer = X509_NAME_oneline (X509_get_issuer_name (cert), 0, 0); logprintf (LOG_NOTQUIET, - _("%s: Certificate verification error for %s: %s\n"), - severity, escnonprint (host), - X509_verify_cert_error_string (vresult)); + _("%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.) */ + with the cert (important with --no-check-certificate.) */ } /* Check that HOST matches the common name in the certificate. @@ -508,27 +569,64 @@ ssl_check_certificate (int fd, const char *host) - Ensure that ASN1 strings from the certificate are encoded as UTF-8 which can be meaningfully compared to HOST. */ + X509_NAME *xname = X509_get_subject_name(cert); common_name[0] = '\0'; - X509_NAME_get_text_by_NID (X509_get_subject_name (cert), - NID_commonName, common_name, sizeof (common_name)); + 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, escnonprint (common_name), escnonprint (host)); +%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) != 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", - escnonprint (host))); + 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"), - escnonprint (host)); + quotearg_style (escape_quoting_style, host)); /* Allow --no-check-cert to disable certificate checking. */ return opt.check_cert ? success : true;