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50c10aa5bf
curl/lib/gtls.c
Daniel Stenberg 50c10aa5bf Patrick Monnerat and I modified libcurl so that now it *copies* all strings 
passed to it with curl_easy_setopt()! Previously it has always just refered
to the data, forcing the user to keep the data around until libcurl is done
with it. That is now history and libcurl will instead clone the given
strings and keep private copies.
2007-08-01 21:20:01 +00:00

698 lines
21 KiB
C
Raw Blame History

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* $Id$
***************************************************************************/
/*
* Source file for all GnuTLS-specific code for the TLS/SSL layer. No code
* but sslgen.c should ever call or use these functions.
*
* Note: don't use the GnuTLS' *_t variable type names in this source code,
* since they were not present in 1.0.X.
*/
#include "setup.h"
#ifdef USE_GNUTLS
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include "urldata.h"
#include "sendf.h"
#include "gtls.h"
#include "sslgen.h"
#include "parsedate.h"
#include "connect.h" /* for the connect timeout */
#include "select.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "memory.h"
/* The last #include file should be: */
#include "memdebug.h"
/* Enable GnuTLS debugging by defining GTLSDEBUG */
/*#define GTLSDEBUG */
#ifdef GTLSDEBUG
static void tls_log_func(int level, const char *str)
{
fprintf(stderr, "|<%d>| %s", level, str);
}
#endif
static bool gtls_inited = FALSE;
/*
* Custom push and pull callback functions used by GNU TLS to read and write
* to the socket. These functions are simple wrappers to send() and recv()
* (although here using the sread/swrite macros as defined by setup_once.h).
* We use custom functions rather than the GNU TLS defaults because it allows
* us to get specific about the fourth "flags" argument, and to use arbitrary
* private data with gnutls_transport_set_ptr if we wish.
*/
static ssize_t Curl_gtls_push(void *s, const void *buf, size_t len)
{
return swrite(s, buf, len);
}
static ssize_t Curl_gtls_pull(void *s, void *buf, size_t len)
{
return sread(s, buf, len);
}
/* Global GnuTLS init, called from Curl_ssl_init() */
int Curl_gtls_init(void)
{
/* Unfortunately we can not init here, things like curl --version will
* fail to work if there is no egd socket available because libgcrypt
* will EXIT the application!!
* By doing the actual init later (before actually trying to use GnuTLS),
* we can at least provide basic info etc.
*/
return 1;
}
static int _Curl_gtls_init(void)
{
int ret = 1;
if (!gtls_inited) {
ret = gnutls_global_init()?0:1;
#ifdef GTLSDEBUG
gnutls_global_set_log_function(tls_log_func);
gnutls_global_set_log_level(2);
#endif
gtls_inited = TRUE;
}
return ret;
}
int Curl_gtls_cleanup(void)
{
if (gtls_inited)
gnutls_global_deinit();
return 1;
}
static void showtime(struct SessionHandle *data,
const char *text,
time_t stamp)
{
struct tm *tm;
#ifdef HAVE_GMTIME_R
struct tm buffer;
tm = (struct tm *)gmtime_r(&stamp, &buffer);
#else
tm = gmtime(&stamp);
#endif
snprintf(data->state.buffer,
BUFSIZE,
"\t %s: %s, %02d %s %4d %02d:%02d:%02d GMT\n",
text,
Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
tm->tm_mday,
Curl_month[tm->tm_mon],
tm->tm_year + 1900,
tm->tm_hour,
tm->tm_min,
tm->tm_sec);
infof(data, "%s", data->state.buffer);
}
/* this function does a BLOCKING SSL/TLS (re-)handshake */
static CURLcode handshake(struct connectdata *conn,
gnutls_session session,
int sockindex,
bool duringconnect)
{
struct SessionHandle *data = conn->data;
int rc;
if (!gtls_inited)
_Curl_gtls_init();
do {
rc = gnutls_handshake(session);
if((rc == GNUTLS_E_AGAIN) || (rc == GNUTLS_E_INTERRUPTED)) {
long timeout_ms = DEFAULT_CONNECT_TIMEOUT;
long has_passed;
if(duringconnect && data->set.connecttimeout)
timeout_ms = data->set.connecttimeout;
if(data->set.timeout) {
/* get the strictest timeout of the ones converted to milliseconds */
if(data->set.timeout < timeout_ms)
timeout_ms = data->set.timeout;
}
/* Evaluate in milliseconds how much time that has passed */
has_passed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle);
/* subtract the passed time */
timeout_ms -= has_passed;
if(timeout_ms < 0) {
/* a precaution, no need to continue if time already is up */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEOUTED;
}
rc = Curl_socket_ready(conn->sock[sockindex],
conn->sock[sockindex], (int)timeout_ms);
if(rc > 0)
/* reabable or writable, go loop*/
continue;
else if(0 == rc) {
/* timeout */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
else {
/* anything that gets here is fatally bad */
failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
return CURLE_SSL_CONNECT_ERROR;
}
}
else
break;
} while(1);
if (rc < 0) {
failf(data, "gnutls_handshake() failed: %s", gnutls_strerror(rc));
return CURLE_SSL_CONNECT_ERROR;
}
return CURLE_OK;
}
static gnutls_x509_crt_fmt do_file_type(const char *type)
{
if(!type || !type[0])
return GNUTLS_X509_FMT_PEM;
if(curl_strequal(type, "PEM"))
return GNUTLS_X509_FMT_PEM;
if(curl_strequal(type, "DER"))
return GNUTLS_X509_FMT_DER;
return -1;
}
/*
* This function is called after the TCP connect has completed. Setup the TLS
* layer and do all necessary magic.
*/
CURLcode
Curl_gtls_connect(struct connectdata *conn,
int sockindex)
{
static const int cert_type_priority[] = { GNUTLS_CRT_X509, 0 };
struct SessionHandle *data = conn->data;
gnutls_session session;
int rc;
unsigned int cert_list_size;
const gnutls_datum *chainp;
unsigned int verify_status;
gnutls_x509_crt x509_cert;
char certbuf[256]; /* big enough? */
size_t size;
unsigned int algo;
unsigned int bits;
time_t clock;
const char *ptr;
void *ssl_sessionid;
size_t ssl_idsize;
if (!gtls_inited) _Curl_gtls_init();
/* GnuTLS only supports TLSv1 (and SSLv3?) */
if(data->set.ssl.version == CURL_SSLVERSION_SSLv2) {
failf(data, "GnuTLS does not support SSLv2");
return CURLE_SSL_CONNECT_ERROR;
}
/* allocate a cred struct */
rc = gnutls_certificate_allocate_credentials(&conn->ssl[sockindex].cred);
if(rc < 0) {
failf(data, "gnutls_cert_all_cred() failed: %s", gnutls_strerror(rc));
return CURLE_SSL_CONNECT_ERROR;
}
if(data->set.ssl.CAfile) {
/* set the trusted CA cert bundle file */
gnutls_certificate_set_verify_flags(conn->ssl[sockindex].cred,
GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
rc = gnutls_certificate_set_x509_trust_file(conn->ssl[sockindex].cred,
data->set.ssl.CAfile,
GNUTLS_X509_FMT_PEM);
if(rc < 0) {
infof(data, "error reading ca cert file %s (%s)\n",
data->set.ssl.CAfile, gnutls_strerror(rc));
if (data->set.ssl.verifypeer)
return CURLE_SSL_CACERT_BADFILE;
}
else
infof(data, "found %d certificates in %s\n",
rc, data->set.ssl.CAfile);
}
/* Initialize TLS session as a client */
rc = gnutls_init(&conn->ssl[sockindex].session, GNUTLS_CLIENT);
if(rc) {
failf(data, "gnutls_init() failed: %d", rc);
return CURLE_SSL_CONNECT_ERROR;
}
/* convenient assign */
session = conn->ssl[sockindex].session;
/* Use default priorities */
rc = gnutls_set_default_priority(session);
if(rc < 0)
return CURLE_SSL_CONNECT_ERROR;
/* Sets the priority on the certificate types supported by gnutls. Priority
is higher for types specified before others. After specifying the types
you want, you must append a 0. */
rc = gnutls_certificate_type_set_priority(session, cert_type_priority);
if(rc < 0)
return CURLE_SSL_CONNECT_ERROR;
if(data->set.str[STRING_CERT]) {
if( gnutls_certificate_set_x509_key_file(
conn->ssl[sockindex].cred,
data->set.str[STRING_CERT],
data->set.str[STRING_KEY] ?
data->set.str[STRING_KEY] : data->set.str[STRING_CERT],
do_file_type(data->set.str[STRING_CERT_TYPE]) ) ) {
failf(data, "error reading X.509 key or certificate file");
return CURLE_SSL_CONNECT_ERROR;
}
}
/* put the credentials to the current session */
rc = gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE,
conn->ssl[sockindex].cred);
/* set the connection handle (file descriptor for the socket) */
gnutls_transport_set_ptr(session,
(gnutls_transport_ptr)conn->sock[sockindex]);
/* register callback functions to send and receive data. */
gnutls_transport_set_push_function(session, Curl_gtls_push);
gnutls_transport_set_pull_function(session, Curl_gtls_pull);
/* lowat must be set to zero when using custom push and pull functions. */
gnutls_transport_set_lowat(session, 0);
/* This might be a reconnect, so we check for a session ID in the cache
to speed up things */
if(!Curl_ssl_getsessionid(conn, &ssl_sessionid, &ssl_idsize)) {
/* we got a session id, use it! */
gnutls_session_set_data(session, ssl_sessionid, ssl_idsize);
/* Informational message */
infof (data, "SSL re-using session ID\n");
}
rc = handshake(conn, session, sockindex, TRUE);
if(rc)
/* handshake() sets its own error message with failf() */
return rc;
/* This function will return the peer's raw certificate (chain) as sent by
the peer. These certificates are in raw format (DER encoded for
X.509). In case of a X.509 then a certificate list may be present. The
first certificate in the list is the peer's certificate, following the
issuer's certificate, then the issuer's issuer etc. */
chainp = gnutls_certificate_get_peers(session, &cert_list_size);
if(!chainp) {
if(data->set.ssl.verifyhost) {
failf(data, "failed to get server cert");
return CURLE_SSL_PEER_CERTIFICATE;
}
infof(data, "\t common name: WARNING couldn't obtain\n");
}
/* This function will try to verify the peer's certificate and return its
status (trusted, invalid etc.). The value of status should be one or more
of the gnutls_certificate_status_t enumerated elements bitwise or'd. To
avoid denial of service attacks some default upper limits regarding the
certificate key size and chain size are set. To override them use
gnutls_certificate_set_verify_limits(). */
rc = gnutls_certificate_verify_peers2(session, &verify_status);
if (rc < 0) {
failf(data, "server cert verify failed: %d", rc);
return CURLE_SSL_CONNECT_ERROR;
}
/* verify_status is a bitmask of gnutls_certificate_status bits */
if(verify_status & GNUTLS_CERT_INVALID) {
if (data->set.ssl.verifypeer) {
failf(data, "server certificate verification failed. CAfile: %s",
data->set.ssl.CAfile?data->set.ssl.CAfile:"none");
return CURLE_SSL_CACERT;
}
else
infof(data, "\t server certificate verification FAILED\n");
}
else
infof(data, "\t server certificate verification OK\n");
/* initialize an X.509 certificate structure. */
gnutls_x509_crt_init(&x509_cert);
/* convert the given DER or PEM encoded Certificate to the native
gnutls_x509_crt_t format */
gnutls_x509_crt_import(x509_cert, chainp, GNUTLS_X509_FMT_DER);
size=sizeof(certbuf);
rc = gnutls_x509_crt_get_dn_by_oid(x509_cert, GNUTLS_OID_X520_COMMON_NAME,
0, /* the first and only one */
FALSE,
certbuf,
&size);
if(rc) {
infof(data, "error fetching CN from cert:%s\n",
gnutls_strerror(rc));
}
/* This function will check if the given certificate's subject matches the
given hostname. This is a basic implementation of the matching described
in RFC2818 (HTTPS), which takes into account wildcards, and the subject
alternative name PKIX extension. Returns non zero on success, and zero on
failure. */
rc = gnutls_x509_crt_check_hostname(x509_cert, conn->host.name);
if(!rc) {
if (data->set.ssl.verifyhost > 1) {
failf(data, "SSL: certificate subject name (%s) does not match "
"target host name '%s'", certbuf, conn->host.dispname);
gnutls_x509_crt_deinit(x509_cert);
return CURLE_SSL_PEER_CERTIFICATE;
}
else
infof(data, "\t common name: %s (does not match '%s')\n",
certbuf, conn->host.dispname);
}
else
infof(data, "\t common name: %s (matched)\n", certbuf);
/* Check for time-based validity */
clock = gnutls_x509_crt_get_expiration_time(x509_cert);
if(clock == (time_t)-1) {
failf(data, "server cert expiration date verify failed");
return CURLE_SSL_CONNECT_ERROR;
}
if(clock < time(NULL)) {
if (data->set.ssl.verifypeer) {
failf(data, "server certificate expiration date has passed.");
return CURLE_SSL_PEER_CERTIFICATE;
}
else
infof(data, "\t server certificate expiration date FAILED\n");
}
else
infof(data, "\t server certificate expiration date OK\n");
clock = gnutls_x509_crt_get_activation_time(x509_cert);
if(clock == (time_t)-1) {
failf(data, "server cert activation date verify failed");
return CURLE_SSL_CONNECT_ERROR;
}
if(clock > time(NULL)) {
if (data->set.ssl.verifypeer) {
failf(data, "server certificate not activated yet.");
return CURLE_SSL_PEER_CERTIFICATE;
}
else
infof(data, "\t server certificate activation date FAILED\n");
}
else
infof(data, "\t server certificate activation date OK\n");
/* Show:
- ciphers used
- subject
- start date
- expire date
- common name
- issuer
*/
/* public key algorithm's parameters */
algo = gnutls_x509_crt_get_pk_algorithm(x509_cert, &bits);
infof(data, "\t certificate public key: %s\n",
gnutls_pk_algorithm_get_name(algo));
/* version of the X.509 certificate. */
infof(data, "\t certificate version: #%d\n",
gnutls_x509_crt_get_version(x509_cert));
size = sizeof(certbuf);
gnutls_x509_crt_get_dn(x509_cert, certbuf, &size);
infof(data, "\t subject: %s\n", certbuf);
clock = gnutls_x509_crt_get_activation_time(x509_cert);
showtime(data, "start date", clock);
clock = gnutls_x509_crt_get_expiration_time(x509_cert);
showtime(data, "expire date", clock);
size = sizeof(certbuf);
gnutls_x509_crt_get_issuer_dn(x509_cert, certbuf, &size);
infof(data, "\t issuer: %s\n", certbuf);
gnutls_x509_crt_deinit(x509_cert);
/* compression algorithm (if any) */
ptr = gnutls_compression_get_name(gnutls_compression_get(session));
/* the *_get_name() says "NULL" if GNUTLS_COMP_NULL is returned */
infof(data, "\t compression: %s\n", ptr);
/* the name of the cipher used. ie 3DES. */
ptr = gnutls_cipher_get_name(gnutls_cipher_get(session));
infof(data, "\t cipher: %s\n", ptr);
/* the MAC algorithms name. ie SHA1 */
ptr = gnutls_mac_get_name(gnutls_mac_get(session));
infof(data, "\t MAC: %s\n", ptr);
if(!ssl_sessionid) {
/* this session was not previously in the cache, add it now */
/* get the session ID data size */
gnutls_session_get_data(session, NULL, &ssl_idsize);
ssl_sessionid = malloc(ssl_idsize); /* get a buffer for it */
if(ssl_sessionid) {
/* extract session ID to the allocated buffer */
gnutls_session_get_data(session, ssl_sessionid, &ssl_idsize);
/* store this session id */
return Curl_ssl_addsessionid(conn, ssl_sessionid, ssl_idsize);
}
}
return CURLE_OK;
}
/* return number of sent (non-SSL) bytes */
ssize_t Curl_gtls_send(struct connectdata *conn,
int sockindex,
void *mem,
size_t len)
{
ssize_t rc = gnutls_record_send(conn->ssl[sockindex].session, mem, len);
if(rc < 0 ) {
if(rc == GNUTLS_E_AGAIN)
return 0; /* EWOULDBLOCK equivalent */
rc = -1; /* generic error code for send failure */
}
return rc;
}
void Curl_gtls_close_all(struct SessionHandle *data)
{
/* FIX: make the OpenSSL code more generic and use parts of it here */
(void)data;
}
static void close_one(struct connectdata *conn,
int index)
{
if(conn->ssl[index].session) {
gnutls_bye(conn->ssl[index].session, GNUTLS_SHUT_RDWR);
gnutls_deinit(conn->ssl[index].session);
conn->ssl[index].session = NULL;
}
if(conn->ssl[index].cred) {
gnutls_certificate_free_credentials(conn->ssl[index].cred);
conn->ssl[index].cred = NULL;
}
}
void Curl_gtls_close(struct connectdata *conn, int sockindex)
{
close_one(conn, sockindex);
}
/*
* This function is called to shut down the SSL layer but keep the
* socket open (CCC - Clear Command Channel)
*/
int Curl_gtls_shutdown(struct connectdata *conn, int sockindex)
{
int result;
int retval = 0;
struct SessionHandle *data = conn->data;
int done = 0;
char buf[120];
/* This has only been tested on the proftpd server, and the mod_tls code
sends a close notify alert without waiting for a close notify alert in
response. Thus we wait for a close notify alert from the server, but
we do not send one. Let's hope other servers do the same... */
if(data->set.ftp_ccc == CURLFTPSSL_CCC_ACTIVE)
gnutls_bye(conn->ssl[sockindex].session, GNUTLS_SHUT_WR);
if(conn->ssl[sockindex].session) {
while(!done) {
int what = Curl_socket_ready(conn->sock[sockindex],
CURL_SOCKET_BAD, SSL_SHUTDOWN_TIMEOUT);
if(what > 0) {
/* Something to read, let's do it and hope that it is the close
notify alert from the server */
result = gnutls_record_recv(conn->ssl[sockindex].session,
buf, sizeof(buf));
switch(result) {
case 0:
/* This is the expected response. There was no data but only
the close notify alert */
done = 1;
break;
case GNUTLS_E_AGAIN:
case GNUTLS_E_INTERRUPTED:
infof(data, "GNUTLS_E_AGAIN || GNUTLS_E_INTERRUPTED\n");
break;
default:
retval = -1;
done = 1;
break;
}
}
else if(0 == what) {
/* timeout */
failf(data, "SSL shutdown timeout");
done = 1;
break;
}
else {
/* anything that gets here is fatally bad */
failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
retval = -1;
done = 1;
}
}
gnutls_deinit(conn->ssl[sockindex].session);
}
gnutls_certificate_free_credentials(conn->ssl[sockindex].cred);
conn->ssl[sockindex].cred = NULL;
conn->ssl[sockindex].session = NULL;
return retval;
}
/*
* If the read would block we return -1 and set 'wouldblock' to TRUE.
* Otherwise we return the amount of data read. Other errors should return -1
* and set 'wouldblock' to FALSE.
*/
ssize_t Curl_gtls_recv(struct connectdata *conn, /* connection data */
int num, /* socketindex */
char *buf, /* store read data here */
size_t buffersize, /* max amount to read */
bool *wouldblock)
{
ssize_t ret;
ret = gnutls_record_recv(conn->ssl[num].session, buf, buffersize);
if((ret == GNUTLS_E_AGAIN) || (ret == GNUTLS_E_INTERRUPTED)) {
*wouldblock = TRUE;
return -1;
}
if(ret == GNUTLS_E_REHANDSHAKE) {
/* BLOCKING call, this is bad but a work-around for now. Fixing this "the
proper way" takes a whole lot of work. */
CURLcode rc = handshake(conn, conn->ssl[num].session, num, FALSE);
if(rc)
/* handshake() writes error message on its own */
return rc;
*wouldblock = TRUE; /* then return as if this was a wouldblock */
return -1;
}
*wouldblock = FALSE;
if (!ret) {
failf(conn->data, "Peer closed the TLS connection");
return -1;
}
if (ret < 0) {
failf(conn->data, "GnuTLS recv error (%d): %s",
(int)ret, gnutls_strerror(ret));
return -1;
}
return ret;
}
void Curl_gtls_session_free(void *ptr)
{
free(ptr);
}
size_t Curl_gtls_version(char *buffer, size_t size)
{
return snprintf(buffer, size, " GnuTLS/%s", gnutls_check_version(NULL));
}
#endif /* USE_GNUTLS */
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