/
gnutls.c
2950 lines (2611 loc) · 82.3 KB
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/*
* OpenConnect (SSL + DTLS) VPN client
*
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* Copyright © 2008-2015 Intel Corporation.
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*
* Author: David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1, as published by the Free Software Foundation.
*
* This program 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
* Lesser General Public License for more details.
*/
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#include <config.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
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#ifndef HAVE_GNUTLS_CERTIFICATE_SET_KEY
/* Shut up about gnutls_sign_callback_set() being deprecated. We only use it
in the GnuTLS 2.12 case, and there just isn't another way of doing it. */
#define GNUTLS_INTERNAL_BUILD 1
#endif
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#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include <gnutls/crypto.h>
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#include <gnutls/pkcs12.h>
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#include <gnutls/abstract.h>
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#ifdef HAVE_TROUSERS
#include <trousers/tss.h>
#include <trousers/trousers.h>
#endif
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#ifdef HAVE_P11KIT
#include <p11-kit/p11-kit.h>
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#include <p11-kit/pkcs11.h>
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#include <p11-kit/pin.h>
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#endif
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#if defined(HAVE_P11KIT) || defined(HAVE_GNUTLS_SYSTEM_KEYS)
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static int gnutls_pin_callback(void *priv, int attempt, const char *uri,
const char *token_label, unsigned int flags,
char *pin, size_t pin_max);
#ifndef HAVE_GNUTLS_X509_CRT_SET_PIN_FUNCTION
/* If we don't have this (3.1.0+) then we'll use p11-kit callbacks instead
* because the old GnuTLS callback was global rather than context-specific,
* which makes it basically unusable from libopenconnect. The p11-kit
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* callback function is a simple wrapper around the GnuTLS native version. */
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typedef enum {
GNUTLS_PIN_USER = (1 << 0),
GNUTLS_PIN_SO = (1 << 1),
GNUTLS_PIN_FINAL_TRY = (1 << 2),
GNUTLS_PIN_COUNT_LOW = (1 << 3),
GNUTLS_PIN_CONTEXT_SPECIFIC = (1 << 4),
GNUTLS_PIN_WRONG = (1 << 5)
} gnutls_pin_flag_t;
static P11KitPin *p11kit_pin_callback(const char *pin_source, P11KitUri *pin_uri,
const char *pin_description,
P11KitPinFlags flags,
void *_vpninfo);
#endif /* !HAVE_GNUTLS_X509_CRT_SET_PIN_FUNCTION */
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#endif /* HAVE_P11KIT || HAVE_GNUTLS_SYSTEM_KEYS */
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#include "gnutls.h"
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#include "openconnect-internal.h"
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/* GnuTLS 2.x lacked this. But GNUTLS_E_UNEXPECTED_PACKET_LENGTH basically
* does the same thing.
* http://lists.infradead.org/pipermail/openconnect-devel/2014-March/001726.html
*/
#ifndef GNUTLS_E_PREMATURE_TERMINATION
#define GNUTLS_E_PREMATURE_TERMINATION GNUTLS_E_UNEXPECTED_PACKET_LENGTH
#endif
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/* Compile-time optimisable GnuTLS version check. We should never be
* run against a version of GnuTLS which is *older* than the one we
* were built again, but we might be run against a version which is
* newer. So some ancient compatibility code *can* be dropped at
* compile time. Likewise, if building against GnuTLS 2.x then we
* can never be running agsinst a 3.x library — the soname changed. */
#define gtls_ver(a,b,c) ( GNUTLS_VERSION_MAJOR >= (a) && \
(GNUTLS_VERSION_NUMBER >= ( ((a) << 16) + ((b) << 8) + (c) ) || \
gnutls_check_version(#a "." #b "." #c)))
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/* Helper functions for reading/writing lines over SSL. */
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static int _openconnect_gnutls_write(gnutls_session_t ses, int fd, struct openconnect_info *vpninfo, char *buf, size_t len)
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{
size_t orig_len = len;
while (len) {
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int done = gnutls_record_send(ses, buf, len);
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if (done > 0)
len -= done;
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else if (done == GNUTLS_E_AGAIN || done == GNUTLS_E_INTERRUPTED) {
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/* Wait for something to happen on the socket, or on cmd_fd */
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fd_set wr_set, rd_set;
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int maxfd = fd;
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FD_ZERO(&wr_set);
FD_ZERO(&rd_set);
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if (gnutls_record_get_direction(ses))
FD_SET(fd, &wr_set);
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else
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FD_SET(fd, &rd_set);
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cmd_fd_set(vpninfo, &rd_set, &maxfd);
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select(maxfd + 1, &rd_set, &wr_set, NULL, NULL);
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if (is_cancel_pending(vpninfo, &rd_set)) {
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vpn_progress(vpninfo, PRG_ERR, _("SSL write cancelled\n"));
return -EINTR;
}
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} else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to write to SSL socket: %s\n"),
gnutls_strerror(done));
return -EIO;
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}
}
return orig_len;
}
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static int openconnect_gnutls_write(struct openconnect_info *vpninfo, char *buf, size_t len)
{
return _openconnect_gnutls_write(vpninfo->https_sess, vpninfo->ssl_fd, vpninfo, buf, len);
}
int openconnect_dtls_write(struct openconnect_info *vpninfo, void *buf, size_t len)
{
return _openconnect_gnutls_write(vpninfo->dtls_ssl, vpninfo->dtls_fd, vpninfo, buf, len);
}
static int _openconnect_gnutls_read(gnutls_session_t ses, int fd, struct openconnect_info *vpninfo, char *buf, size_t len, unsigned ms)
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{
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int done, ret;
struct timeval timeout, *tv = NULL;
if (ms) {
timeout.tv_sec = ms/1000;
timeout.tv_usec = (ms%1000)*1000;
tv = &timeout;
}
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while ((done = gnutls_record_recv(ses, buf, len)) < 0) {
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if (done == GNUTLS_E_AGAIN || done == GNUTLS_E_INTERRUPTED) {
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/* Wait for something to happen on the socket, or on cmd_fd */
fd_set wr_set, rd_set;
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int maxfd = fd;
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FD_ZERO(&wr_set);
FD_ZERO(&rd_set);
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if (gnutls_record_get_direction(ses))
FD_SET(fd, &wr_set);
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else
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FD_SET(fd, &rd_set);
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cmd_fd_set(vpninfo, &rd_set, &maxfd);
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ret = select(maxfd + 1, &rd_set, &wr_set, NULL, tv);
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if (is_cancel_pending(vpninfo, &rd_set)) {
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vpn_progress(vpninfo, PRG_ERR, _("SSL read cancelled\n"));
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done = -EINTR;
goto cleanup;
}
if (ret == 0) {
done = -ETIMEDOUT;
goto cleanup;
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}
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} else if (done == GNUTLS_E_PREMATURE_TERMINATION) {
/* We've seen this with HTTP 1.0 responses followed by abrupt
socket closure and no clean SSL shutdown.
https://bugs.launchpad.net/bugs/1225276 */
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vpn_progress(vpninfo, PRG_DEBUG, _("SSL socket closed uncleanly\n"));
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done = 0;
goto cleanup;
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} else if (done == GNUTLS_E_REHANDSHAKE) {
int ret = cstp_handshake(vpninfo, 0);
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if (ret) {
done = ret;
goto cleanup;
}
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} else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to read from SSL socket: %s\n"),
gnutls_strerror(done));
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if (done == GNUTLS_E_TIMEDOUT) {
done = -ETIMEDOUT;
goto cleanup;
} else {
done = -EIO;
goto cleanup;
}
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}
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}
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cleanup:
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return done;
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}
static int openconnect_gnutls_read(struct openconnect_info *vpninfo, char *buf, size_t len)
{
return _openconnect_gnutls_read(vpninfo->https_sess, vpninfo->ssl_fd, vpninfo, buf, len, 0);
}
int openconnect_dtls_read(struct openconnect_info *vpninfo, void *buf, size_t len, unsigned ms)
{
return _openconnect_gnutls_read(vpninfo->dtls_ssl, vpninfo->dtls_fd, vpninfo, buf, len, ms);
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}
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static int openconnect_gnutls_gets(struct openconnect_info *vpninfo, char *buf, size_t len)
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{
int i = 0;
int ret;
if (len < 2)
return -EINVAL;
while (1) {
ret = gnutls_record_recv(vpninfo->https_sess, buf + i, 1);
if (ret == 1) {
if (buf[i] == '\n') {
buf[i] = 0;
if (i && buf[i-1] == '\r') {
buf[i-1] = 0;
i--;
}
return i;
}
i++;
if (i >= len - 1) {
buf[i] = 0;
return i;
}
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} else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED) {
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/* Wait for something to happen on the socket, or on cmd_fd */
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fd_set rd_set, wr_set;
int maxfd = vpninfo->ssl_fd;
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FD_ZERO(&rd_set);
FD_ZERO(&wr_set);
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if (gnutls_record_get_direction(vpninfo->https_sess))
FD_SET(vpninfo->ssl_fd, &wr_set);
else
FD_SET(vpninfo->ssl_fd, &rd_set);
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cmd_fd_set(vpninfo, &rd_set, &maxfd);
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select(maxfd + 1, &rd_set, &wr_set, NULL, NULL);
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if (is_cancel_pending(vpninfo, &rd_set)) {
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vpn_progress(vpninfo, PRG_ERR, _("SSL read cancelled\n"));
ret = -EINTR;
break;
}
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} else if (ret == GNUTLS_E_REHANDSHAKE) {
ret = cstp_handshake(vpninfo, 0);
if (ret)
return ret;
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} else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to read from SSL socket: %s\n"),
gnutls_strerror(ret));
ret = -EIO;
break;
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}
}
buf[i] = 0;
return i ?: ret;
}
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int ssl_nonblock_read(struct openconnect_info *vpninfo, void *buf, int maxlen)
{
int ret;
ret = gnutls_record_recv(vpninfo->https_sess, buf, maxlen);
if (ret > 0)
return ret;
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if (ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED) {
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vpn_progress(vpninfo, PRG_ERR,
_("SSL read error: %s; reconnecting.\n"),
gnutls_strerror(ret));
return -EIO;
}
return 0;
}
int ssl_nonblock_write(struct openconnect_info *vpninfo, void *buf, int buflen)
{
int ret;
ret = gnutls_record_send(vpninfo->https_sess, buf, buflen);
if (ret > 0)
return ret;
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if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED) {
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/*
* Before 3.3.13, GnuTLS could return zero instead of one,
* indicating that it was waiting for a read when in fact
* it was waiting for a write. That caused us to block for
* ever, waiting for the read that it said it wanted.
*
* So instead, just *assume* it actually wants a write.
* Which is true most of the time, and on the rare occasion
* that it *isn't* true, the failure mode will just be that
* we keep waking up and calling GnuTLS again until the read
* that it's waiting for does arrive.
*/
if (GNUTLS_VERSION_NUMBER < 0x03030d ||
gnutls_record_get_direction(vpninfo->https_sess)) {
/* Waiting for the socket to become writable — it's
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probably stalled, and/or the buffers are full */
monitor_write_fd(vpninfo, ssl);
}
return 0;
}
vpn_progress(vpninfo, PRG_ERR, _("SSL send failed: %s\n"),
gnutls_strerror(ret));
return -1;
}
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static int check_certificate_expiry(struct openconnect_info *vpninfo, gnutls_x509_crt_t cert)
{
const char *reason = NULL;
time_t expires = gnutls_x509_crt_get_expiration_time(cert);
time_t now = time(NULL);
if (expires == -1) {
vpn_progress(vpninfo, PRG_ERR,
_("Could not extract expiration time of certificate\n"));
return -EINVAL;
}
if (expires < now)
reason = _("Client certificate has expired at");
else if (expires < now + vpninfo->cert_expire_warning)
reason = _("Client certificate expires soon at");
if (reason) {
char buf[80];
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#ifdef _WIN32
/*
* Windows doesn't have gmtime_r but apparently its gmtime()
* *is* thread-safe because it uses a per-thread static buffer.
* cf. http://sourceforge.net/p/mingw/bugs/1625/
*
* We also explicitly say 'GMT' because %Z would give us the
* Microsoft stupidity "GMT Standard Time". Which is not only
* silly, but also ambiguous because Windows actually says that
* even when it means British Summer Time (GMT+1). And having
* used gmtime() we really *are* giving the time in GMT.
*/
struct tm *tm = gmtime(&expires);
strftime(buf, 80, "%a, %d %b %Y %H:%M:%S GMT", tm);
#else
struct tm tm;
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gmtime_r(&expires, &tm);
strftime(buf, 80, "%a, %d %b %Y %T %Z", &tm);
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#endif
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vpn_progress(vpninfo, PRG_ERR, "%s: %s\n", reason, buf);
}
return 0;
}
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static int load_datum(struct openconnect_info *vpninfo,
gnutls_datum_t *datum, const char *fname)
{
struct stat st;
int fd, err;
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#ifdef ANDROID_KEYSTORE
if (!strncmp(fname, "keystore:", 9)) {
int len;
const char *p = fname + 9;
/* Skip first two slashes if the user has given it as
keystore://foo ... */
if (*p == '/')
p++;
if (*p == '/')
p++;
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len = keystore_fetch(p, &datum->data);
if (len <= 0) {
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vpn_progress(vpninfo, PRG_ERR,
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_("Failed to load item '%s' from keystore: %s\n"),
p, keystore_strerror(len));
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return -EINVAL;
}
datum->size = len;
return 0;
}
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#endif /* ANDROID_KEYSTORE */
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fd = openconnect_open_utf8(vpninfo, fname, O_RDONLY|O_CLOEXEC|O_BINARY);
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if (fd == -1) {
err = errno;
vpn_progress(vpninfo, PRG_ERR,
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_("Failed to open key/certificate file %s: %s\n"),
fname, strerror(err));
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return -ENOENT;
}
if (fstat(fd, &st)) {
err = errno;
vpn_progress(vpninfo, PRG_ERR,
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_("Failed to stat key/certificate file %s: %s\n"),
fname, strerror(err));
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close(fd);
return -EIO;
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}
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datum->size = st.st_size;
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datum->data = gnutls_malloc(st.st_size + 1);
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if (!datum->data) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to allocate certificate buffer\n"));
close(fd);
return -ENOMEM;
}
errno = EAGAIN;
if (read(fd, datum->data, datum->size) != datum->size) {
err = errno;
vpn_progress(vpninfo, PRG_ERR,
_("Failed to read certificate into memory: %s\n"),
strerror(err));
close(fd);
gnutls_free(datum->data);
return -EIO;
}
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datum->data[st.st_size] = 0;
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close(fd);
return 0;
}
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/* A non-zero, non-error return to make load_certificate() continue and
interpreting the file as other types */
#define NOT_PKCS12 1
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static int load_pkcs12_certificate(struct openconnect_info *vpninfo,
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gnutls_datum_t *datum,
gnutls_x509_privkey_t *key,
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gnutls_x509_crt_t **chain,
unsigned int *chain_len,
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gnutls_x509_crt_t **extra_certs,
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unsigned int *extra_certs_len,
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gnutls_x509_crl_t *crl)
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{
gnutls_pkcs12_t p12;
char *pass;
int err;
err = gnutls_pkcs12_init(&p12);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to setup PKCS#12 data structure: %s\n"),
gnutls_strerror(err));
return -EIO;
}
err = gnutls_pkcs12_import(p12, datum, GNUTLS_X509_FMT_DER, 0);
if (err) {
gnutls_pkcs12_deinit(p12);
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return NOT_PKCS12;
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}
pass = vpninfo->cert_password;
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while ((err = gnutls_pkcs12_verify_mac(p12, pass)) == GNUTLS_E_MAC_VERIFY_FAILED) {
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if (!pass) {
/* OpenSSL's PKCS12_parse() code will try both NULL and "" automatically,
* but GnuTLS requires two separate attempts. */
err = gnutls_pkcs12_verify_mac(p12, "");
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if (!err) {
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pass = strdup("");
break;
}
} else
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vpn_progress(vpninfo, PRG_ERR,
_("Failed to decrypt PKCS#12 certificate file\n"));
free(pass);
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vpninfo->cert_password = NULL;
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err = request_passphrase(vpninfo, "openconnect_pkcs12", &pass,
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_("Enter PKCS#12 pass phrase:"));
if (err) {
gnutls_pkcs12_deinit(p12);
return -EINVAL;
}
}
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/* If it wasn't GNUTLS_E_MAC_VERIFY_FAILED, then the problem wasn't just a
bad password. Give up. */
if (err) {
int level = PRG_ERR;
int ret = -EINVAL;
gnutls_pkcs12_deinit(p12);
/* If the first attempt, and we didn't know for sure it was PKCS#12
anyway, bail out and try loading it as something different. */
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if (pass == vpninfo->cert_password) {
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/* Make it non-fatal... */
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level = PRG_DEBUG;
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ret = NOT_PKCS12;
}
vpn_progress(vpninfo, level,
_("Failed to process PKCS#12 file: %s\n"),
gnutls_strerror(err));
return ret;
}
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err = gnutls_pkcs12_simple_parse(p12, pass, key, chain, chain_len,
extra_certs, extra_certs_len, crl, 0);
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free(pass);
vpninfo->cert_password = NULL;
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gnutls_pkcs12_deinit(p12);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to load PKCS#12 certificate: %s\n"),
gnutls_strerror(err));
return -EINVAL;
}
return 0;
}
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/* Older versions of GnuTLS didn't actually bother to check this, so we'll
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do it for them. Is there a bug reference for this? Or just the git commit
reference (c1ef7efb in master, 5196786c in gnutls_3_0_x-2)? */
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static int check_issuer_sanity(gnutls_x509_crt_t cert, gnutls_x509_crt_t issuer)
{
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#if GNUTLS_VERSION_NUMBER > 0x030014
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return 0;
#else
unsigned char id1[512], id2[512];
size_t id1_size = 512, id2_size = 512;
int err;
err = gnutls_x509_crt_get_authority_key_id(cert, id1, &id1_size, NULL);
if (err)
return 0;
err = gnutls_x509_crt_get_subject_key_id(issuer, id2, &id2_size, NULL);
if (err)
return 0;
if (id1_size == id2_size && !memcmp(id1, id2, id1_size))
return 0;
/* EEP! */
return -EIO;
#endif
}
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static int count_x509_certificates(gnutls_datum_t *datum)
{
int count = 0;
char *p = (char *)datum->data;
while (p) {
p = strstr(p, "-----BEGIN ");
if (!p)
break;
p += 11;
if (!strncmp(p, "CERTIFICATE", 11) ||
!strncmp(p, "X509 CERTIFICATE", 16))
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count++;
579
580
581
582
}
return count;
}
583
584
585
586
587
588
589
590
591
592
593
594
static int get_cert_name(gnutls_x509_crt_t cert, char *name, size_t namelen)
{
if (gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME,
0, 0, name, &namelen) &&
gnutls_x509_crt_get_dn(cert, name, &namelen)) {
name[namelen-1] = 0;
snprintf(name, namelen-1, "<unknown>");
return -EINVAL;
}
return 0;
}
595
#if defined(HAVE_P11KIT) || defined(HAVE_TROUSERS) || defined (HAVE_GNUTLS_SYSTEM_KEYS)
596
#ifndef HAVE_GNUTLS_CERTIFICATE_SET_KEY
597
598
599
600
601
602
603
604
/* For GnuTLS 2.12 even if we *have* a privkey (as we do for PKCS#11), we
can't register it. So we have to use the cert_callback function. This
just hands out the certificate chain we prepared in load_certificate().
If we have a pkey then return that too; otherwise leave the key NULL —
we'll also have registered a sign_callback for the session, which will
handle that. */
static int gtls_cert_cb(gnutls_session_t sess, const gnutls_datum_t *req_ca_dn,
int nreqs, const gnutls_pk_algorithm_t *pk_algos,
605
int pk_algos_length, gnutls_retr2_st *st) {
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
struct openconnect_info *vpninfo = gnutls_session_get_ptr(sess);
int algo = GNUTLS_PK_RSA; /* TPM */
int i;
#ifdef HAVE_P11KIT
if (vpninfo->my_p11key) {
st->key_type = GNUTLS_PRIVKEY_PKCS11;
st->key.pkcs11 = vpninfo->my_p11key;
algo = gnutls_pkcs11_privkey_get_pk_algorithm(vpninfo->my_p11key, NULL);
};
#endif
for (i = 0; i < pk_algos_length; i++) {
if (algo == pk_algos[i])
break;
}
if (i == pk_algos_length)
return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
st->cert_type = GNUTLS_CRT_X509;
st->cert.x509 = vpninfo->my_certs;
st->ncerts = vpninfo->nr_my_certs;
st->deinit_all = 0;
return 0;
}
632
633
634
635
636
637
638
639
640
641
/* For GnuTLS 2.12, this has to set the cert_callback to the function
above, which will return the pkey and certs on demand. Or in the
case of TPM we can't make a suitable pkey, so we have to set a
sign_callback too (which is done in openconnect_open_https() since
it has to be done on the *session*). */
static int assign_privkey(struct openconnect_info *vpninfo,
gnutls_privkey_t pkey,
gnutls_x509_crt_t *certs,
unsigned int nr_certs,
642
uint8_t *free_certs)
643
644
645
646
647
{
vpninfo->my_certs = gnutls_calloc(nr_certs, sizeof(*certs));
if (!vpninfo->my_certs)
return GNUTLS_E_MEMORY_ERROR;
648
vpninfo->free_my_certs = gnutls_malloc(nr_certs);
649
if (!vpninfo->free_my_certs) {
650
651
652
653
654
655
gnutls_free(vpninfo->my_certs);
vpninfo->my_certs = NULL;
return GNUTLS_E_MEMORY_ERROR;
}
memcpy(vpninfo->free_my_certs, free_certs, nr_certs);
656
657
658
memcpy(vpninfo->my_certs, certs, nr_certs * sizeof(*certs));
vpninfo->nr_my_certs = nr_certs;
659
660
/* We are *keeping* the certs, unlike in GnuTLS 3 where our caller
can free them after gnutls_certificate_set_key() has been called.
661
662
So wipe the 'free_certs' array. */
memset(free_certs, 0, nr_certs);
663
664
665
666
667
668
669
gnutls_certificate_set_retrieve_function(vpninfo->https_cred,
gtls_cert_cb);
vpninfo->my_pkey = pkey;
return 0;
}
670
#else /* !SET_KEY */
671
672
673
674
675
676
677
678
679
/* For GnuTLS 3+ this is saner than the GnuTLS 2.12 version. But still we
have to convert the array of X509 certificates to gnutls_pcert_st for
ourselves. There's no function that takes a gnutls_privkey_t as the key
and gnutls_x509_crt_t certificates. */
static int assign_privkey(struct openconnect_info *vpninfo,
gnutls_privkey_t pkey,
gnutls_x509_crt_t *certs,
unsigned int nr_certs,
680
uint8_t *free_certs)
681
682
683
684
685
686
687
{
gnutls_pcert_st *pcerts = calloc(nr_certs, sizeof(*pcerts));
int i, err;
if (!pcerts)
return GNUTLS_E_MEMORY_ERROR;
688
for (i = 0 ; i < nr_certs; i++) {
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
err = gnutls_pcert_import_x509(pcerts + i, certs[i], 0);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Importing X509 certificate failed: %s\n"),
gnutls_strerror(err));
goto free_pcerts;
}
}
err = gnutls_certificate_set_key(vpninfo->https_cred, NULL, 0,
pcerts, nr_certs, pkey);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Setting PKCS#11 certificate failed: %s\n"),
gnutls_strerror(err));
free_pcerts:
705
for (i = 0 ; i < nr_certs; i++)
706
gnutls_pcert_deinit(pcerts + i);
707
free(pcerts);
708
709
710
711
}
return err;
}
#endif /* !SET_KEY */
712
713
714
715
static int verify_signed_data(gnutls_pubkey_t pubkey, gnutls_privkey_t privkey,
const gnutls_datum_t *data, const gnutls_datum_t *sig)
{
716
#ifdef HAVE_GNUTLS_PK_TO_SIGN
717
718
719
720
721
722
723
724
725
726
727
gnutls_sign_algorithm_t algo = GNUTLS_SIGN_RSA_SHA1; /* TPM keys */
if (privkey != OPENCONNECT_TPM_PKEY)
algo = gnutls_pk_to_sign(gnutls_privkey_get_pk_algorithm(privkey, NULL),
GNUTLS_DIG_SHA1);
return gnutls_pubkey_verify_data2(pubkey, algo, 0, data, sig);
#else
return gnutls_pubkey_verify_data(pubkey, 0, data, sig);
#endif
}
728
#endif /* (P11KIT || TROUSERS || SYSTEM_KEYS) */
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
static int openssl_hash_password(struct openconnect_info *vpninfo, char *pass,
gnutls_datum_t *key, gnutls_datum_t *salt)
{
unsigned char md5[16];
gnutls_hash_hd_t hash;
int count = 0;
int err;
while (count < key->size) {
err = gnutls_hash_init(&hash, GNUTLS_DIG_MD5);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Could not initialise MD5 hash: %s\n"),
gnutls_strerror(err));
return -EIO;
}
if (count) {
err = gnutls_hash(hash, md5, sizeof(md5));
if (err) {
hash_err:
gnutls_hash_deinit(hash, NULL);
vpn_progress(vpninfo, PRG_ERR,
_("MD5 hash error: %s\n"),
gnutls_strerror(err));
return -EIO;
}
}
if (pass) {
err = gnutls_hash(hash, pass, strlen(pass));
if (err)
goto hash_err;
}
762
763
/* We only use the first 8 bytes of the salt for this */
err = gnutls_hash(hash, salt->data, 8);
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
if (err)
goto hash_err;
gnutls_hash_deinit(hash, md5);
if (key->size - count <= sizeof(md5)) {
memcpy(&key->data[count], md5, key->size - count);
break;
}
memcpy(&key->data[count], md5, sizeof(md5));
count += sizeof(md5);
}
return 0;
}
static int import_openssl_pem(struct openconnect_info *vpninfo,
gnutls_x509_privkey_t key,
char type, char *pem_header, size_t pem_size)
{
gnutls_cipher_hd_t handle;
gnutls_cipher_algorithm_t cipher;
gnutls_datum_t constructed_pem;
gnutls_datum_t b64_data;
gnutls_datum_t salt, enc_key;
unsigned char *key_data;
const char *begin;
792
char *pass, *p;
793
char *pem_start = pem_header;
794
int ret, err, i;
795
796
797
798
799
800
if (type == 'E')
begin = "EC PRIVATE KEY";
else if (type == 'R')
begin = "RSA PRIVATE KEY";
else if (type == 'D')
801
begin = "DSA PRIVATE KEY";
802
803
804
805
806
807
808
809
810
811
812
813
else
return -EINVAL;
while (*pem_header == '\r' || *pem_header == '\n')
pem_header++;
if (strncmp(pem_header, "DEK-Info: ", 10)) {
vpn_progress(vpninfo, PRG_ERR,
_("Missing DEK-Info: header from OpenSSL encrypted key\n"));
return -EIO;
}
pem_header += 10;
814
815
816
817
818
p = strchr(pem_header, ',');
if (!p) {
vpn_progress(vpninfo, PRG_ERR,
_("Cannot determine PEM encryption type\n"));
return -EINVAL;
819
}
820
821
822
823
824
825
826
827
828
*p = 0;
cipher = gnutls_cipher_get_id(pem_header);
/* GnuTLS calls this '3DES-CBC' but all other names match */
if (cipher == GNUTLS_CIPHER_UNKNOWN &&
!strcmp(pem_header, "DES-EDE3-CBC"))
cipher = GNUTLS_CIPHER_3DES_CBC;
if (cipher == GNUTLS_CIPHER_UNKNOWN) {
829
830
831
832
833
vpn_progress(vpninfo, PRG_ERR,
_("Unsupported PEM encryption type: %s\n"),
pem_header);
return -EINVAL;
}
834
835
836
837
838
pem_header = p + 1;
/* No supported algorithms have an IV larger than this, and dynamically
allocating it would be painful. */
salt.size = 64;
839
840
841
842
843
844
845
846
847
848
849
salt.data = malloc(salt.size);
if (!salt.data)
return -ENOMEM;
for (i = 0; i < salt.size * 2; i++) {
unsigned char x;
char *c = &pem_header[i];
if (*c >= '0' && *c <= '9')
x = (*c) - '0';
else if (*c >= 'A' && *c <= 'F')
x = (*c) - 'A' + 10;
850
851
852
853
else if ((*c == '\r' || *c == '\n') && i >= 16 && !(i % 16)) {
salt.size = i / 2;
break;
} else {
854
855
856
857
858
859
860
861
862
863
864
865
866
867
vpn_progress(vpninfo, PRG_ERR,
_("Invalid salt in encrypted PEM file\n"));
ret = -EINVAL;
goto out_salt;
}
if (i & 1)
salt.data[i/2] |= x;
else
salt.data[i/2] = x << 4;
}
pem_header += salt.size * 2;
if (*pem_header != '\r' && *pem_header != '\n') {
vpn_progress(vpninfo, PRG_ERR,
868
_("Invalid salt in encrypted PEM file\n"));
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
ret = -EINVAL;
goto out_salt;
}
while (*pem_header == '\n' || *pem_header == '\r')
pem_header++;
/* pem_header should now point to the start of the base64 content.
Put a -----BEGIN banner in place before it, so that we can use
gnutls_pem_base64_decode_alloc(). The banner has to match the
-----END banner, so make sure we get it right... */
pem_header -= 6;
memcpy(pem_header, "-----\n", 6);
pem_header -= strlen(begin);
memcpy(pem_header, begin, strlen(begin));
pem_header -= 11;
memcpy(pem_header, "-----BEGIN ", 11);
constructed_pem.data = (void *)pem_header;
constructed_pem.size = pem_size - (pem_header - pem_start);
err = gnutls_pem_base64_decode_alloc(begin, &constructed_pem, &b64_data);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Error base64-decoding encrypted PEM file: %s\n"),
gnutls_strerror(err));
ret = -EINVAL;
goto out_salt;
}
if (b64_data.size < 16) {
/* Just to be sure our parsing is OK */
vpn_progress(vpninfo, PRG_ERR,
_("Encrypted PEM file too short\n"));
ret = -EINVAL;
goto out_b64;
}
ret = -ENOMEM;
enc_key.size = gnutls_cipher_get_key_size(cipher);
enc_key.data = malloc(enc_key.size);
if (!enc_key.data)
goto out_b64;
key_data = malloc(b64_data.size);
if (!key_data)
goto out_enc_key;
pass = vpninfo->cert_password;
vpninfo->cert_password = NULL;
while (1) {
memcpy(key_data, b64_data.data, b64_data.size);
ret = openssl_hash_password(vpninfo, pass, &enc_key, &salt);
if (ret)
goto out;
err = gnutls_cipher_init(&handle, cipher, &enc_key, &salt);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to initialise cipher for decrypting PEM file: %s\n"),
gnutls_strerror(err));
gnutls_cipher_deinit(handle);
ret = -EIO;
goto out;
}
err = gnutls_cipher_decrypt(handle, key_data, b64_data.size);
gnutls_cipher_deinit(handle);
if (err) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to decrypt PEM key: %s\n"),
gnutls_strerror(err));
ret = -EIO;
goto out;
}
/* We have to strip any padding for GnuTLS to accept it.
So a bit more ASN.1 parsing for us.
FIXME: Consolidate with similar code in gnutls_tpm.c */
if (key_data[0] == 0x30) {
gnutls_datum_t key_datum;
int blocksize = gnutls_cipher_get_block_size(cipher);
int keylen = key_data[1];
int ofs = 2;
if (keylen & 0x80) {
int lenlen = keylen & 0x7f;
keylen = 0;
if (lenlen > 3)
goto fail;
while (lenlen) {
keylen <<= 8;
keylen |= key_data[ofs++];
lenlen--;
}
}
keylen += ofs;
969
970
/* If there appears to be more or less padding than required, fail */
if (b64_data.size - keylen > blocksize || b64_data.size < keylen + 1)
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
goto fail;
/* If the padding bytes aren't all equal to the amount of padding, fail */
ofs = keylen;
while (ofs < b64_data.size) {
if (key_data[ofs] != b64_data.size - keylen)
goto fail;
ofs++;
}
key_datum.data = key_data;
key_datum.size = keylen;
err = gnutls_x509_privkey_import(key, &key_datum, GNUTLS_X509_FMT_DER);
if (!err) {
ret = 0;
goto out;
}
}
fail:
if (pass) {
vpn_progress(vpninfo, PRG_ERR, _("Decrypting PEM key failed\n"));
free(pass);
993
pass = NULL;
994
995
996
997
998
999
1000
}
err = request_passphrase(vpninfo, "openconnect_pem",
&pass, _("Enter PEM pass phrase:"));
if (err) {
ret = -EINVAL;
goto out;
}