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gnutls.c
2702 lines (2382 loc) · 74.5 KB
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gnutls.c
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/*
* OpenConnect (SSL + DTLS) VPN client
*
* Copyright © 2008-2015 Intel Corporation.
*
* 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.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include <gnutls/crypto.h>
#include <gnutls/pkcs12.h>
#include <gnutls/abstract.h>
#ifdef HAVE_P11KIT
#include <p11-kit/p11-kit.h>
#include <p11-kit/pkcs11.h>
#include <p11-kit/pin.h>
#endif
#if defined(HAVE_P11KIT) || defined(HAVE_GNUTLS_SYSTEM_KEYS)
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);
#endif /* HAVE_P11KIT || HAVE_GNUTLS_SYSTEM_KEYS */
#include "gnutls.h"
#include "openconnect-internal.h"
/* 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
/* GnuTLS 3.5.0 added this flag to send a client cert, even if its issuer is
* mismatched to the list of issuers requested by the server. OpenSSL does
* this by default.
* https://github.com/curl/curl/issues/1411
*/
#ifndef GNUTLS_FORCE_CLIENT_CERT
#define GNUTLS_FORCE_CLIENT_CERT 0
#endif
static char tls_library_version[32] = "";
const char *openconnect_get_tls_library_version()
{
if (!*tls_library_version) {
snprintf(tls_library_version, sizeof(tls_library_version), "GnuTLS %s",
gnutls_check_version(NULL));
}
return tls_library_version;
}
int can_enable_insecure_crypto()
{
int ret = 0;
if (setenv("GNUTLS_SYSTEM_PRIORITY_FILE", DEVNULL, 1) < 0)
return -errno;
gnutls_global_deinit();
ret = openconnect_init_ssl();
if (ret)
return ret;
/* XX: As of GnuTLS 3.6.13, no released version has (yet) removed 3DES/RC4 from default builds,
* but like OpenSSL (removed in 1.1.0) it may happen. */
if (gnutls_cipher_get_id("3DES-CBC") == GNUTLS_CIPHER_UNKNOWN ||
gnutls_cipher_get_id("ARCFOUR-128") == GNUTLS_CIPHER_UNKNOWN)
ret = -ENOENT;
return ret;
}
/* Helper functions for reading/writing lines over TLS/DTLS. */
static int _openconnect_gnutls_write(gnutls_session_t ses, int fd, struct openconnect_info *vpninfo, char *buf, size_t len)
{
size_t orig_len = len;
while (len) {
int done = gnutls_record_send(ses, buf, len);
if (done > 0)
len -= done;
else if (done == GNUTLS_E_AGAIN || done == GNUTLS_E_INTERRUPTED) {
/* Wait for something to happen on the socket, or on cmd_fd */
fd_set wr_set, rd_set;
int maxfd = fd;
FD_ZERO(&wr_set);
FD_ZERO(&rd_set);
if (gnutls_record_get_direction(ses))
FD_SET(fd, &wr_set);
else
FD_SET(fd, &rd_set);
cmd_fd_set(vpninfo, &rd_set, &maxfd);
if (select(maxfd + 1, &rd_set, &wr_set, NULL, NULL) < 0 &&
errno != EINTR) {
vpn_perror(vpninfo, _("Failed select() for TLS"));
return -EIO;
}
if (is_cancel_pending(vpninfo, &rd_set)) {
vpn_progress(vpninfo, PRG_ERR, _("TLS/DTLS write cancelled\n"));
return -EINTR;
}
} else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to write to TLS/DTLS socket: %s\n"),
gnutls_strerror(done));
return -EIO;
}
}
return orig_len;
}
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)
{
int done, ret;
struct timeval timeout, *tv = NULL;
if (ms) {
timeout.tv_sec = ms/1000;
timeout.tv_usec = (ms%1000)*1000;
tv = &timeout;
}
while ((done = gnutls_record_recv(ses, buf, len)) < 0) {
if (done == GNUTLS_E_AGAIN || done == GNUTLS_E_INTERRUPTED) {
/* Wait for something to happen on the socket, or on cmd_fd */
fd_set wr_set, rd_set;
int maxfd = fd;
FD_ZERO(&wr_set);
FD_ZERO(&rd_set);
if (gnutls_record_get_direction(ses))
FD_SET(fd, &wr_set);
else
FD_SET(fd, &rd_set);
cmd_fd_set(vpninfo, &rd_set, &maxfd);
ret = select(maxfd + 1, &rd_set, &wr_set, NULL, tv);
if (ret < 0 && errno != EINTR) {
vpn_perror(vpninfo, _("Failed select() for TLS/DTLS"));
return -EIO;
}
if (is_cancel_pending(vpninfo, &rd_set)) {
vpn_progress(vpninfo, PRG_ERR, _("TLS/DTLS read cancelled\n"));
done = -EINTR;
goto cleanup;
}
if (ret == 0) {
done = -ETIMEDOUT;
goto cleanup;
}
} 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 */
vpn_progress(vpninfo, PRG_DEBUG, _("TLS/DTLS socket closed uncleanly\n"));
done = 0;
goto cleanup;
} else if (done == GNUTLS_E_REHANDSHAKE) {
int ret = cstp_handshake(vpninfo, 0);
if (ret) {
done = ret;
goto cleanup;
}
} else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to read from TLS/DTLS socket: %s\n"),
gnutls_strerror(done));
if (done == GNUTLS_E_TIMEDOUT) {
done = -ETIMEDOUT;
goto cleanup;
} else {
done = -EIO;
goto cleanup;
}
}
}
cleanup:
return done;
}
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);
}
static int openconnect_gnutls_gets(struct openconnect_info *vpninfo, char *buf, size_t len)
{
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;
}
} else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED) {
/* Wait for something to happen on the socket, or on cmd_fd */
fd_set rd_set, wr_set;
int maxfd = vpninfo->ssl_fd;
FD_ZERO(&rd_set);
FD_ZERO(&wr_set);
if (gnutls_record_get_direction(vpninfo->https_sess))
FD_SET(vpninfo->ssl_fd, &wr_set);
else
FD_SET(vpninfo->ssl_fd, &rd_set);
cmd_fd_set(vpninfo, &rd_set, &maxfd);
if (select(maxfd + 1, &rd_set, &wr_set, NULL, NULL) < 0 &&
errno != EINTR) {
vpn_perror(vpninfo, _("Failed select() for TLS"));
return -EIO;
}
if (is_cancel_pending(vpninfo, &rd_set)) {
vpn_progress(vpninfo, PRG_ERR, _("TLS/DTLS read cancelled\n"));
ret = -EINTR;
break;
}
} else if (ret == GNUTLS_E_REHANDSHAKE) {
ret = cstp_handshake(vpninfo, 0);
if (ret)
return ret;
} else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to read from TLS/DTLS socket: %s\n"),
gnutls_strerror(ret));
ret = -EIO;
break;
}
}
buf[i] = 0;
return i ?: ret;
}
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;
if (ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED) {
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;
if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED) {
/*
* 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
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;
}
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];
#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;
gmtime_r(&expires, &tm);
strftime(buf, 80, "%a, %d %b %Y %T %Z", &tm);
#endif
vpn_progress(vpninfo, PRG_ERR, "%s: %s\n", reason, buf);
}
return 0;
}
static int load_datum(struct openconnect_info *vpninfo,
gnutls_datum_t *datum, const char *fname)
{
struct stat st;
int fd, err;
#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++;
len = keystore_fetch(p, &datum->data);
if (len <= 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to load item '%s' from keystore: %s\n"),
p, keystore_strerror(len));
return -EINVAL;
}
datum->size = len;
return 0;
}
#endif /* ANDROID_KEYSTORE */
fd = openconnect_open_utf8(vpninfo, fname, O_RDONLY|O_CLOEXEC|O_BINARY);
if (fd == -1) {
err = errno;
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open key/certificate file %s: %s\n"),
fname, strerror(err));
return -ENOENT;
}
if (fstat(fd, &st)) {
err = errno;
vpn_progress(vpninfo, PRG_ERR,
_("Failed to stat key/certificate file %s: %s\n"),
fname, strerror(err));
close(fd);
return -EIO;
}
datum->size = st.st_size;
datum->data = gnutls_malloc(st.st_size + 1);
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;
}
datum->data[st.st_size] = 0;
close(fd);
return 0;
}
/* A non-zero, non-error return to make load_certificate() continue and
interpreting the file as other types */
#define NOT_PKCS12 1
static int load_pkcs12_certificate(struct openconnect_info *vpninfo,
gnutls_datum_t *datum,
gnutls_x509_privkey_t *key,
gnutls_x509_crt_t **chain,
unsigned int *chain_len,
gnutls_x509_crt_t **extra_certs,
unsigned int *extra_certs_len,
gnutls_x509_crl_t *crl)
{
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);
return NOT_PKCS12;
}
pass = vpninfo->cert_password;
while ((err = gnutls_pkcs12_verify_mac(p12, pass)) == GNUTLS_E_MAC_VERIFY_FAILED) {
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, "");
if (!err) {
pass = strdup("");
break;
}
} else
vpn_progress(vpninfo, PRG_ERR,
_("Failed to decrypt PKCS#12 certificate file\n"));
free_pass(&pass);
vpninfo->cert_password = NULL;
err = request_passphrase(vpninfo, "openconnect_pkcs12", &pass,
_("Enter PKCS#12 pass phrase:"));
if (err) {
gnutls_pkcs12_deinit(p12);
return -EINVAL;
}
}
/* 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. */
if (pass == vpninfo->cert_password) {
/* Make it non-fatal... */
level = PRG_DEBUG;
ret = NOT_PKCS12;
}
vpn_progress(vpninfo, level,
_("Failed to process PKCS#12 file: %s\n"),
gnutls_strerror(err));
return ret;
}
err = gnutls_pkcs12_simple_parse(p12, pass, key, chain, chain_len,
extra_certs, extra_certs_len, crl, 0);
free_pass(&pass);
vpninfo->cert_password = NULL;
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;
}
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))
count++;
}
return count;
}
static int get_cert_name(gnutls_x509_crt_t cert, char *name, size_t namelen)
{
/* When the name buffer is not big enough, gnutls_x509_crt_get_dn*() will
* update the length argument to the required size, and return
* GNUTLS_E_SHORT_MEMORY_BUFFER. We need to avoid clobbering the original
* length variable. */
size_t nl = namelen;
if (gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME,
0, 0, name, &nl)) {
nl = namelen;
if (gnutls_x509_crt_get_dn(cert, name, &nl)) {
name[namelen-1] = 0;
snprintf(name, namelen-1, "<unknown>");
return -EINVAL;
}
}
return 0;
}
#if defined(HAVE_P11KIT) || defined(HAVE_TROUSERS) || defined(HAVE_TSS2) || defined (HAVE_GNUTLS_SYSTEM_KEYS)
/* 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,
uint8_t *free_certs)
{
gnutls_pcert_st *pcerts = gnutls_calloc(nr_certs, sizeof(*pcerts));
unsigned int i;
int err;
if (!pcerts)
return GNUTLS_E_MEMORY_ERROR;
for (i = 0 ; i < nr_certs; i++) {
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:
for (i = 0 ; i < nr_certs; i++)
gnutls_pcert_deinit(pcerts + i);
}
free(pcerts);
return err;
}
static int verify_signed_data(gnutls_pubkey_t pubkey, gnutls_privkey_t privkey,
gnutls_digest_algorithm_t dig,
const gnutls_datum_t *data, const gnutls_datum_t *sig)
{
gnutls_sign_algorithm_t algo;
unsigned flags = 0;
#ifdef GNUTLS_VERIFY_ALLOW_BROKEN
flags |= GNUTLS_VERIFY_ALLOW_BROKEN;
#endif
algo = gnutls_pk_to_sign(gnutls_privkey_get_pk_algorithm(privkey, NULL),
dig);
return gnutls_pubkey_verify_data2(pubkey, algo, flags, data, sig);
}
#endif /* (P11KIT || TROUSERS || TSS2 || SYSTEM_KEYS) */
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;
}
/* We only use the first 8 bytes of the salt for this */
err = gnutls_hash(hash, salt->data, 8);
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;
char *pass, *p;
char *pem_start = pem_header;
int ret, err, i;
if (type == 'E')
begin = "EC PRIVATE KEY";
else if (type == 'R')
begin = "RSA PRIVATE KEY";
else if (type == 'D')
begin = "DSA PRIVATE KEY";
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;
p = strchr(pem_header, ',');
if (!p) {
vpn_progress(vpninfo, PRG_ERR,
_("Cannot determine PEM encryption type\n"));
return -EINVAL;
}
*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) {
vpn_progress(vpninfo, PRG_ERR,
_("Unsupported PEM encryption type: %s\n"),
pem_header);
return -EINVAL;
}
pem_header = p + 1;
/* No supported algorithms have an IV larger than this, and dynamically
allocating it would be painful. */
salt.size = 64;
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;
else if ((*c == '\r' || *c == '\n') && i >= 16 && !(i % 16)) {
salt.size = i / 2;
break;
} else {
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,
_("Invalid salt in encrypted PEM file\n"));
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;
/* If there appears to be more or less padding than required, fail */
if (b64_data.size - keylen > blocksize || b64_data.size < keylen + 1)
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(&pass);
}
err = request_passphrase(vpninfo, "openconnect_pem",
&pass, _("Enter PEM pass phrase:"));
if (err) {
ret = -EINVAL;
goto out;
}
}
out:
free(key_data);
free_pass(&pass);
out_enc_key:
free(enc_key.data);
out_b64:
free(b64_data.data);
out_salt:
free(salt.data);
return ret;
}
static void fill_token_info(char *buf, size_t s, unsigned char *dst, size_t dstlen)
{
if (s && !gtls_ver(3,6,0))
s--;
if (s > dstlen)
s = dstlen;
memcpy(dst, buf, s);
if (s < dstlen)
memset(dst + s, ' ', dstlen - s);
}
static int load_certificate(struct openconnect_info *vpninfo)
{
gnutls_datum_t fdata;
gnutls_x509_privkey_t key = NULL;
#if defined(HAVE_P11KIT) || defined(HAVE_TROUSERS) || defined(HAVE_TSS2) || defined(HAVE_GNUTLS_SYSTEM_KEYS)
gnutls_privkey_t pkey = NULL;
gnutls_datum_t pkey_sig = {NULL, 0};
void *dummy_hash_data = &load_certificate;
#endif
#if defined(HAVE_P11KIT) || defined(HAVE_GNUTLS_SYSTEM_KEYS)
char *cert_url = (char *)vpninfo->cert;
#endif
#ifdef HAVE_P11KIT
char *key_url = (char *)vpninfo->sslkey;
gnutls_pkcs11_privkey_t p11key = NULL;
#endif
char *pem_header;
gnutls_x509_crl_t crl = NULL;
gnutls_x509_crt_t last_cert, cert = NULL;
gnutls_x509_crt_t *extra_certs = NULL, *supporting_certs = NULL;
unsigned int nr_supporting_certs = 0, nr_extra_certs = 0;
uint8_t *free_supporting_certs = NULL;
int err; /* GnuTLS error */
int ret;
int i;
int cert_is_p11 = 0, key_is_p11 = 0;
int cert_is_sys = 0, key_is_sys = 0;
unsigned char key_id[20];
size_t key_id_size = sizeof(key_id);
char name[80];
fdata.data = NULL;
key_is_p11 = !strncmp(vpninfo->sslkey, "pkcs11:", 7);
cert_is_p11 = !strncmp(vpninfo->cert, "pkcs11:", 7);
/* GnuTLS returns true for pkcs11:, tpmkey:, system:, and custom URLs. */
key_is_sys = !key_is_p11 && gnutls_url_is_supported(vpninfo->sslkey);
cert_is_sys = !cert_is_p11 && gnutls_url_is_supported(vpninfo->cert);
#ifndef HAVE_GNUTLS_SYSTEM_KEYS
if (key_is_sys || cert_is_sys) {
vpn_progress(vpninfo, PRG_ERR,
_("This binary built without system key support\n"));
return -EINVAL;
}
#endif
#ifndef HAVE_P11KIT
if (key_is_p11 || cert_is_p11) {
vpn_progress(vpninfo, PRG_ERR,
_("This binary built without PKCS#11 support\n"));
return -EINVAL;
}
#else
/* Install PIN handler if either certificate or key are coming from PKCS#11 */
if (key_is_p11 || cert_is_p11) {
CK_OBJECT_CLASS class;
CK_ATTRIBUTE attr;
P11KitUri *uri;
uri = p11_kit_uri_new();
attr.type = CKA_CLASS;