/
openssl.c
1508 lines (1307 loc) · 38.2 KB
/
openssl.c
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/*
* OpenConnect (SSL + DTLS) VPN client
*
* Copyright © 2008-2012 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.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to:
*
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/engine.h>
#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/pkcs12.h>
#include <openssl/x509v3.h>
#include <openssl/x509.h>
#include <openssl/bio.h>
#include "openconnect-internal.h"
int openconnect_sha1(unsigned char *result, void *data, int len)
{
EVP_MD_CTX c;
EVP_MD_CTX_init(&c);
EVP_Digest(data, len, result, NULL, EVP_sha1(), NULL);
EVP_MD_CTX_cleanup(&c);
return 0;
}
int openconnect_get_cert_DER(struct openconnect_info *vpninfo,
OPENCONNECT_X509 *cert, unsigned char **buf)
{
BIO *bp = BIO_new(BIO_s_mem());
BUF_MEM *certinfo;
size_t l;
if (!i2d_X509_bio(bp, cert)) {
BIO_free(bp);
return -EIO;
}
BIO_get_mem_ptr(bp, &certinfo);
l = certinfo->length;
*buf = malloc(l);
if (!*buf) {
BIO_free(bp);
return -ENOMEM;
}
memcpy(*buf, certinfo->data, l);
BIO_free(bp);
return l;
}
int openconnect_random(void *bytes, int len)
{
if (RAND_bytes(bytes, len) != 1)
return -EIO;
return 0;
}
/* Helper functions for reading/writing lines over SSL.
We could use cURL for the HTTP stuff, but it's overkill */
int openconnect_SSL_write(struct openconnect_info *vpninfo, char *buf, size_t len)
{
size_t orig_len = len;
while (len) {
int done = SSL_write(vpninfo->https_ssl, buf, len);
if (done > 0)
len -= done;
else {
int err = SSL_get_error(vpninfo->https_ssl, done);
fd_set wr_set, rd_set;
int maxfd = vpninfo->ssl_fd;
FD_ZERO(&wr_set);
FD_ZERO(&rd_set);
if (err == SSL_ERROR_WANT_READ)
FD_SET(vpninfo->ssl_fd, &rd_set);
else if (err == SSL_ERROR_WANT_WRITE)
FD_SET(vpninfo->ssl_fd, &wr_set);
else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to write to SSL socket\n"));
openconnect_report_ssl_errors(vpninfo);
return -EIO;
}
if (vpninfo->cancel_fd != -1) {
FD_SET(vpninfo->cancel_fd, &rd_set);
if (vpninfo->cancel_fd > vpninfo->ssl_fd)
maxfd = vpninfo->cancel_fd;
}
select(maxfd + 1, &rd_set, &wr_set, NULL, NULL);
if (vpninfo->cancel_fd != -1 &&
FD_ISSET(vpninfo->cancel_fd, &rd_set)) {
vpn_progress(vpninfo, PRG_ERR, _("SSL write cancelled\n"));
return -EINTR;
}
}
}
return orig_len;
}
int openconnect_SSL_read(struct openconnect_info *vpninfo, char *buf, size_t len)
{
int done;
while ((done = SSL_read(vpninfo->https_ssl, buf, len)) == -1) {
int err = SSL_get_error(vpninfo->https_ssl, done);
fd_set wr_set, rd_set;
int maxfd = vpninfo->ssl_fd;
FD_ZERO(&wr_set);
FD_ZERO(&rd_set);
if (err == SSL_ERROR_WANT_READ)
FD_SET(vpninfo->ssl_fd, &rd_set);
else if (err == SSL_ERROR_WANT_WRITE)
FD_SET(vpninfo->ssl_fd, &wr_set);
else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to read from SSL socket\n"));
openconnect_report_ssl_errors(vpninfo);
return -EIO;
}
if (vpninfo->cancel_fd != -1) {
FD_SET(vpninfo->cancel_fd, &rd_set);
if (vpninfo->cancel_fd > vpninfo->ssl_fd)
maxfd = vpninfo->cancel_fd;
}
select(maxfd + 1, &rd_set, &wr_set, NULL, NULL);
if (vpninfo->cancel_fd != -1 &&
FD_ISSET(vpninfo->cancel_fd, &rd_set)) {
vpn_progress(vpninfo, PRG_ERR, _("SSL read cancelled\n"));
return -EINTR;
}
}
return done;
}
int openconnect_SSL_gets(struct openconnect_info *vpninfo, char *buf, size_t len)
{
int i = 0;
int ret;
if (len < 2)
return -EINVAL;
while (1) {
ret = SSL_read(vpninfo->https_ssl, 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 {
fd_set rd_set, wr_set;
int maxfd = vpninfo->ssl_fd;
FD_ZERO(&rd_set);
FD_ZERO(&wr_set);
ret = SSL_get_error(vpninfo->https_ssl, ret);
if (ret == SSL_ERROR_WANT_READ)
FD_SET(vpninfo->ssl_fd, &rd_set);
else if (ret == SSL_ERROR_WANT_WRITE)
FD_SET(vpninfo->ssl_fd, &wr_set);
else {
vpn_progress(vpninfo, PRG_ERR, _("Failed to read from SSL socket\n"));
openconnect_report_ssl_errors(vpninfo);
ret = -EIO;
break;
}
if (vpninfo->cancel_fd != -1) {
FD_SET(vpninfo->cancel_fd, &rd_set);
if (vpninfo->cancel_fd > vpninfo->ssl_fd)
maxfd = vpninfo->cancel_fd;
}
select(maxfd + 1, &rd_set, &wr_set, NULL, NULL);
if (vpninfo->cancel_fd != -1 &&
FD_ISSET(vpninfo->cancel_fd, &rd_set)) {
vpn_progress(vpninfo, PRG_ERR, _("SSL read cancelled\n"));
ret = -EINTR;
break;
}
}
}
buf[i] = 0;
return i ?: ret;
}
/* UI handling. All this just to handle the PIN callback from the TPM ENGINE,
and turn it into a call to our ->process_auth_form function */
struct ui_data {
struct openconnect_info *vpninfo;
struct oc_form_opt **last_opt;
struct oc_auth_form form;
};
struct ui_form_opt {
struct oc_form_opt opt;
UI_STRING *uis;
};
/* Ick. But there is no way to pass this sanely through OpenSSL */
static struct openconnect_info *ui_vpninfo;
static int ui_open(UI *ui)
{
struct openconnect_info *vpninfo = ui_vpninfo; /* Ick */
struct ui_data *ui_data;
if (!vpninfo || !vpninfo->process_auth_form)
return 0;
ui_data = malloc(sizeof(*ui_data));
if (!ui_data)
return 0;
memset(ui_data, 0, sizeof(*ui_data));
ui_data->last_opt = &ui_data->form.opts;
ui_data->vpninfo = vpninfo;
ui_data->form.auth_id = (char *)"openssl_ui";
UI_add_user_data(ui, ui_data);
return 1;
}
static int ui_write(UI *ui, UI_STRING *uis)
{
struct ui_data *ui_data = UI_get0_user_data(ui);
struct ui_form_opt *opt;
switch(UI_get_string_type(uis)) {
case UIT_ERROR:
ui_data->form.error = (char *)UI_get0_output_string(uis);
break;
case UIT_INFO:
ui_data->form.message = (char *)UI_get0_output_string(uis);
break;
case UIT_PROMPT:
opt = malloc(sizeof(*opt));
if (!opt)
return 1;
memset(opt, 0, sizeof(*opt));
opt->uis = uis;
opt->opt.label = opt->opt.name = (char *)UI_get0_output_string(uis);
if (UI_get_input_flags(uis) & UI_INPUT_FLAG_ECHO)
opt->opt.type = OC_FORM_OPT_TEXT;
else
opt->opt.type = OC_FORM_OPT_PASSWORD;
*(ui_data->last_opt) = &opt->opt;
ui_data->last_opt = &opt->opt.next;
break;
default:
fprintf(stderr, "Unhandled SSL UI request type %d\n",
UI_get_string_type(uis));
return 0;
}
return 1;
}
static int ui_flush(UI *ui)
{
struct ui_data *ui_data = UI_get0_user_data(ui);
struct openconnect_info *vpninfo = ui_data->vpninfo;
struct ui_form_opt *opt;
int ret;
ret = vpninfo->process_auth_form(vpninfo->cbdata, &ui_data->form);
if (ret)
return 0;
for (opt = (struct ui_form_opt *)ui_data->form.opts; opt;
opt = (struct ui_form_opt *)opt->opt.next) {
if (opt->opt.value && opt->uis)
UI_set_result(ui, opt->uis, opt->opt.value);
}
return 1;
}
static int ui_close(UI *ui)
{
struct ui_data *ui_data = UI_get0_user_data(ui);
struct ui_form_opt *opt, *next_opt;
opt = (struct ui_form_opt *)ui_data->form.opts;
while (opt) {
next_opt = (struct ui_form_opt *)opt->opt.next;
if (opt->opt.value)
free(opt->opt.value);
free(opt);
opt = next_opt;
}
free(ui_data);
UI_add_user_data(ui, NULL);
return 1;
}
static UI_METHOD *create_openssl_ui(struct openconnect_info *vpninfo)
{
UI_METHOD *ui_method = UI_create_method((char *)"AnyConnect VPN UI");
/* There is a race condition here because of the use of the
static ui_vpninfo pointer. This sucks, but it's OpenSSL's
fault and in practice it's *never* going to hurt us.
This UI is only used for loading certificates from a TPM; for
PKCS#12 and PEM files we hook the passphrase request differently.
The ui_vpninfo variable is set here, and is used from ui_open()
when the TPM ENGINE decides it needs to ask the user for a PIN.
The race condition exists because theoretically, there
could be more than one thread using libopenconnect and
trying to authenticate to a VPN server, within the *same*
process. And if *both* are using certificates from the TPM,
and *both* manage to be within that short window of time
between setting ui_vpninfo and invoking ui_open() to fetch
the PIN, then one connection's ->process_auth_form() could
get a PIN request for the *other* connection.
However, the only thing that ever does run libopenconnect more
than once from the same process is KDE's NetworkManager support,
and NetworkManager doesn't *support* having more than one VPN
connected anyway, so first that would have to be fixed and then
you'd have to connect to two VPNs simultaneously by clicking
'connect' on both at *exactly* the same time and then getting
*really* unlucky.
Oh, and the KDE support won't be using OpenSSL anyway because of
licensing conflicts... so although this sucks, I'm not going to
lose sleep over it.
*/
ui_vpninfo = vpninfo;
/* Set up a UI method of our own for password/passphrase requests */
UI_method_set_opener(ui_method, ui_open);
UI_method_set_writer(ui_method, ui_write);
UI_method_set_flusher(ui_method, ui_flush);
UI_method_set_closer(ui_method, ui_close);
return ui_method;
}
static int pem_pw_cb(char *buf, int len, int w, void *v)
{
struct openconnect_info *vpninfo = v;
char *pass = NULL;
int plen;
if (vpninfo->cert_password) {
pass = vpninfo->cert_password;
vpninfo->cert_password = NULL;
} else if (request_passphrase(vpninfo, "openconnect_pem",
&pass, _("Enter PEM pass phrase:")))
return -1;
plen = strlen(pass);
if (len <= plen) {
vpn_progress(vpninfo, PRG_ERR,
_("PEM password too long (%d >= %d)\n"),
plen, len);
free(pass);
return -1;
}
memcpy(buf, pass, plen+1);
free(pass);
return plen;
}
static int load_pkcs12_certificate(struct openconnect_info *vpninfo, PKCS12 *p12)
{
EVP_PKEY *pkey = NULL;
X509 *cert = NULL;
STACK_OF(X509) *ca;
int ret = 0;
char *pass;
pass = vpninfo->cert_password;
vpninfo->cert_password = NULL;
retrypass:
/* We do this every time round the loop, to work around a bug in
OpenSSL < 1.0.0-beta2 -- where the stack at *ca will be freed
when PKCS12_parse() returns an error, but *ca is left pointing
to the freed memory. */
ca = NULL;
if (!pass && request_passphrase(vpninfo, "openconnect_pkcs12", &pass,
_("Enter PKCS#12 pass phrase:")) < 0) {
PKCS12_free(p12);
return -EINVAL;
}
if (!PKCS12_parse(p12, pass, &pkey, &cert, &ca)) {
unsigned long err = ERR_peek_error();
openconnect_report_ssl_errors(vpninfo);
if (ERR_GET_LIB(err) == ERR_LIB_PKCS12 &&
ERR_GET_FUNC(err) == PKCS12_F_PKCS12_PARSE &&
ERR_GET_REASON(err) == PKCS12_R_MAC_VERIFY_FAILURE) {
vpn_progress(vpninfo, PRG_ERR,
_("Parse PKCS#12 failed (wrong passphrase?)\n"));
free(pass);
pass = NULL;
goto retrypass;
}
vpn_progress(vpninfo, PRG_ERR,
_("Parse PKCS#12 failed (see above errors)\n"));
PKCS12_free(p12);
free(pass);
return -EINVAL;
}
free(pass);
if (cert) {
char buf[200];
vpninfo->cert_x509 = cert;
SSL_CTX_use_certificate(vpninfo->https_ctx, cert);
X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf));
vpn_progress(vpninfo, PRG_INFO,
_("Using client certificate '%s'\n"), buf);
} else {
vpn_progress(vpninfo, PRG_ERR,
_("PKCS#12 contained no certificate!"));
ret = -EINVAL;
}
if (pkey) {
SSL_CTX_use_PrivateKey(vpninfo->https_ctx, pkey);
EVP_PKEY_free(pkey);
} else {
vpn_progress(vpninfo, PRG_ERR,
_("PKCS#12 contained no private key!"));
ret = -EINVAL;
}
/* Only include supporting certificates which are actually necessary */
if (ca) {
int i;
next:
for (i = 0; i < sk_X509_num(ca); i++) {
X509 *cert2 = sk_X509_value(ca, i);
if (X509_check_issued(cert2, cert) == X509_V_OK) {
char buf[200];
if (cert2 == cert)
break;
if (X509_check_issued(cert2, cert2) == X509_V_OK)
break;
X509_NAME_oneline(X509_get_subject_name(cert2),
buf, sizeof(buf));
vpn_progress(vpninfo, PRG_DEBUG,
_("Extra cert from PKCS#12: '%s'\n"), buf);
CRYPTO_add(&cert2->references, 1, CRYPTO_LOCK_X509);
SSL_CTX_add_extra_chain_cert(vpninfo->https_ctx, cert2);
cert = cert2;
goto next;
}
}
sk_X509_pop_free(ca, X509_free);
}
PKCS12_free(p12);
return ret;
}
#ifdef HAVE_ENGINE
static int load_tpm_certificate(struct openconnect_info *vpninfo)
{
ENGINE *e;
EVP_PKEY *key;
UI_METHOD *meth = NULL;
int ret = 0;
ENGINE_load_builtin_engines();
e = ENGINE_by_id("tpm");
if (!e) {
vpn_progress(vpninfo, PRG_ERR, _("Can't load TPM engine.\n"));
openconnect_report_ssl_errors(vpninfo);
return -EINVAL;
}
if (!ENGINE_init(e) || !ENGINE_set_default_RSA(e) ||
!ENGINE_set_default_RAND(e)) {
vpn_progress(vpninfo, PRG_ERR, _("Failed to init TPM engine\n"));
openconnect_report_ssl_errors(vpninfo);
ENGINE_free(e);
return -EINVAL;
}
if (vpninfo->cert_password) {
if (!ENGINE_ctrl_cmd(e, "PIN", strlen(vpninfo->cert_password),
vpninfo->cert_password, NULL, 0)) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to set TPM SRK password\n"));
openconnect_report_ssl_errors(vpninfo);
}
vpninfo->cert_password = NULL;
free(vpninfo->cert_password);
} else {
/* Provide our own UI method to handle the PIN callback. */
meth = create_openssl_ui(vpninfo);
}
key = ENGINE_load_private_key(e, vpninfo->sslkey, meth, NULL);
if (meth)
UI_destroy_method(meth);
if (!key) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to load TPM private key\n"));
openconnect_report_ssl_errors(vpninfo);
ret = -EINVAL;
goto out;
}
if (!SSL_CTX_use_PrivateKey(vpninfo->https_ctx, key)) {
vpn_progress(vpninfo, PRG_ERR, _("Add key from TPM failed\n"));
openconnect_report_ssl_errors(vpninfo);
ret = -EINVAL;
}
EVP_PKEY_free(key);
out:
ENGINE_finish(e);
ENGINE_free(e);
return ret;
}
#else
static int load_tpm_certificate(struct openconnect_info *vpninfo)
{
vpn_progress(vpninfo, PRG_ERR,
_("This version of OpenConnect was built without TPM support\n"));
return -EINVAL;
}
#endif
static int reload_pem_cert(struct openconnect_info *vpninfo)
{
BIO *b = BIO_new(BIO_s_file_internal());
char buf[200];
if (!b)
return -ENOMEM;
if (BIO_read_filename(b, vpninfo->cert) <= 0) {
err:
BIO_free(b);
vpn_progress(vpninfo, PRG_ERR,
_("Failed to reload X509 cert for expiry check\n"));
openconnect_report_ssl_errors(vpninfo);
return -EIO;
}
vpninfo->cert_x509 = PEM_read_bio_X509_AUX(b, NULL, NULL, NULL);
BIO_free(b);
if (!vpninfo->cert_x509)
goto err;
X509_NAME_oneline(X509_get_subject_name(vpninfo->cert_x509), buf, sizeof(buf));
vpn_progress(vpninfo, PRG_INFO,
_("Using client certificate '%s'\n"), buf);
return 0;
}
#ifdef ANDROID_KEYSTORE
static BIO *BIO_from_keystore(struct openconnect_info *vpninfo, const char *item)
{
unsigned char *content;
BIO *b;
int len;
const char *p = item + 9;
/* Skip first two slashes if the user has given it as
keystore://foo ... */
if (*p == '/')
p++;
if (*p == '/')
p++;
len = keystore_fetch(p, &content);
if (len < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to load item '%s' from keystore: %s\n"),
p, keystore_strerror(len));
return NULL;
}
if (!(b = BIO_new(BIO_s_mem())) || BIO_write(b, content, len) != len) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to create BIO for keystore item '%s'\n"),
p);
free(content);
BIO_free(b);
return NULL;
}
free(content);
return b;
}
#endif
static int is_pem_password_error(struct openconnect_info *vpninfo)
{
unsigned long err = ERR_peek_error();
openconnect_report_ssl_errors(vpninfo);
#ifndef EVP_F_EVP_DECRYPTFINAL_EX
#define EVP_F_EVP_DECRYPTFINAL_EX EVP_F_EVP_DECRYPTFINAL
#endif
/* If the user fat-fingered the passphrase, try again */
if (ERR_GET_LIB(err) == ERR_LIB_EVP &&
ERR_GET_FUNC(err) == EVP_F_EVP_DECRYPTFINAL_EX &&
ERR_GET_REASON(err) == EVP_R_BAD_DECRYPT) {
vpn_progress(vpninfo, PRG_ERR,
_("Loading private key failed (wrong passphrase?)\n"));
ERR_clear_error();
return 1;
}
vpn_progress(vpninfo, PRG_ERR,
_("Loading private key failed (see above errors)\n"));
return 0;
}
static int load_certificate(struct openconnect_info *vpninfo)
{
if (!strncmp(vpninfo->sslkey, "pkcs11:", 7) ||
!strncmp(vpninfo->cert, "pkcs11:", 7)) {
vpn_progress(vpninfo, PRG_ERR,
_("This binary built without PKCS#11 support\n"));
return -EINVAL;
}
vpn_progress(vpninfo, PRG_TRACE,
_("Using certificate file %s\n"), vpninfo->cert);
if (strncmp(vpninfo->cert, "keystore:", 9) &&
(vpninfo->cert_type == CERT_TYPE_PKCS12 ||
vpninfo->cert_type == CERT_TYPE_UNKNOWN)) {
FILE *f;
PKCS12 *p12;
f = fopen(vpninfo->cert, "r");
if (!f) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open certificate file %s: %s\n"),
vpninfo->cert, strerror(errno));
return -ENOENT;
}
p12 = d2i_PKCS12_fp(f, NULL);
fclose(f);
if (p12)
return load_pkcs12_certificate(vpninfo, p12);
/* Not PKCS#12 */
if (vpninfo->cert_type == CERT_TYPE_PKCS12) {
vpn_progress(vpninfo, PRG_ERR, _("Read PKCS#12 failed\n"));
openconnect_report_ssl_errors(vpninfo);
return -EINVAL;
}
/* Clear error and fall through to see if it's a PEM file... */
ERR_clear_error();
}
/* It's PEM or TPM now, and either way we need to load the plain cert: */
#ifdef ANDROID_KEYSTORE
if (!strncmp(vpninfo->cert, "keystore:", 9)) {
BIO *b = BIO_from_keystore(vpninfo, vpninfo->cert);
if (!b)
return -EINVAL;
vpninfo->cert_x509 = PEM_read_bio_X509_AUX(b, NULL, pem_pw_cb, vpninfo);
BIO_free(b);
if (!vpninfo->cert_x509) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to load X509 certificate from keystore\n"));
openconnect_report_ssl_errors(vpninfo);
return -EINVAL;
}
if (!SSL_CTX_use_certificate(vpninfo->https_ctx, vpninfo->cert_x509)) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to use X509 certificate from keystore\n"));
openconnect_report_ssl_errors(vpninfo);
X509_free(vpninfo->cert_x509);
vpninfo->cert_x509 = NULL;
return -EINVAL;
}
} else
#endif /* ANDROID_KEYSTORE */
{
if (!SSL_CTX_use_certificate_chain_file(vpninfo->https_ctx,
vpninfo->cert)) {
vpn_progress(vpninfo, PRG_ERR,
_("Loading certificate failed\n"));
openconnect_report_ssl_errors(vpninfo);
return -EINVAL;
}
/* Ew, we can't get it back from the OpenSSL CTX in any sane fashion */
reload_pem_cert(vpninfo);
}
#ifdef ANDROID_KEYSTORE
if (!strncmp(vpninfo->sslkey, "keystore:", 9)) {
EVP_PKEY *key;
BIO *b;
again_android:
b = BIO_from_keystore(vpninfo, vpninfo->sslkey);
if (!b)
return -EINVAL;
key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb, vpninfo);
BIO_free(b);
if (!key) {
if (is_pem_password_error(vpninfo))
goto again_android;
return -EINVAL;
}
if (!SSL_CTX_use_PrivateKey(vpninfo->https_ctx, key)) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to use private key from keystore\n"));
EVP_PKEY_free(key);
X509_free(vpninfo->cert_x509);
vpninfo->cert_x509 = NULL;
return -EINVAL;
}
return 0;
}
#endif /* ANDROID */
if (vpninfo->cert_type == CERT_TYPE_UNKNOWN) {
FILE *f = fopen(vpninfo->sslkey, "r");
char buf[256];
if (!f) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open private key file %s: %s\n"),
vpninfo->cert, strerror(errno));
return -ENOENT;
}
buf[255] = 0;
while (fgets(buf, 255, f)) {
if (!strcmp(buf, "-----BEGIN TSS KEY BLOB-----\n")) {
vpninfo->cert_type = CERT_TYPE_TPM;
break;
} else if (!strcmp(buf, "-----BEGIN RSA PRIVATE KEY-----\n") ||
!strcmp(buf, "-----BEGIN DSA PRIVATE KEY-----\n") ||
!strcmp(buf, "-----BEGIN ENCRYPTED PRIVATE KEY-----\n")) {
vpninfo->cert_type = CERT_TYPE_PEM;
break;
}
}
fclose(f);
if (vpninfo->cert_type == CERT_TYPE_UNKNOWN) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to identify private key type in '%s'\n"),
vpninfo->sslkey);
return -EINVAL;
}
}
if (vpninfo->cert_type == CERT_TYPE_TPM)
return load_tpm_certificate(vpninfo);
/* Standard PEM certificate */
SSL_CTX_set_default_passwd_cb(vpninfo->https_ctx, pem_pw_cb);
SSL_CTX_set_default_passwd_cb_userdata(vpninfo->https_ctx, vpninfo);
again:
if (!SSL_CTX_use_RSAPrivateKey_file(vpninfo->https_ctx, vpninfo->sslkey,
SSL_FILETYPE_PEM)) {
if (is_pem_password_error(vpninfo))
goto again;
return -EINVAL;
}
return 0;
}
static int get_cert_fingerprint(struct openconnect_info *vpninfo,
OPENCONNECT_X509 *cert, const EVP_MD *type,
char *buf)
{
unsigned char md[EVP_MAX_MD_SIZE];
unsigned int i, n;
if (!X509_digest(cert, type, md, &n))
return -ENOMEM;
for (i=0; i < n; i++)
sprintf(&buf[i*2], "%02X", md[i]);
return 0;
}
int get_cert_md5_fingerprint(struct openconnect_info *vpninfo,
OPENCONNECT_X509 *cert, char *buf)
{
return get_cert_fingerprint(vpninfo, cert, EVP_md5(), buf);
}
int openconnect_get_cert_sha1(struct openconnect_info *vpninfo,
OPENCONNECT_X509 *cert, char *buf)
{
return get_cert_fingerprint(vpninfo, cert, EVP_sha1(), buf);
}
static int check_server_cert(struct openconnect_info *vpninfo, X509 *cert)
{
char fingerprint[EVP_MAX_MD_SIZE * 2 + 1];
int ret;
ret = openconnect_get_cert_sha1(vpninfo, cert, fingerprint);
if (ret)
return ret;
if (strcasecmp(vpninfo->servercert, fingerprint)) {
vpn_progress(vpninfo, PRG_ERR,
_("Server SSL certificate didn't match: %s\n"), fingerprint);
return -EINVAL;
}
return 0;
}
static int match_hostname_elem(const char *hostname, int helem_len,
const char *match, int melem_len)
{
if (!helem_len && !melem_len)
return 0;
if (!helem_len || !melem_len)
return -1;
if (match[0] == '*') {
int i;
for (i = 1 ; i <= helem_len; i++) {
if (!match_hostname_elem(hostname + i, helem_len - i,
match + 1, melem_len - 1))
return 0;
}
return -1;
}
/* From the NetBSD (5.1) man page for ctype(3):
Values of type char or signed char must first be cast to unsigned char,
to ensure that the values are within the correct range. The result
should then be cast to int to avoid warnings from some compilers.
We do indeed get warning "array subscript has type 'char'" without
the casts. Ick. */
if (toupper((int)(unsigned char)hostname[0]) ==
toupper((int)(unsigned char)match[0]))
return match_hostname_elem(hostname + 1, helem_len - 1,
match + 1, melem_len - 1);
return -1;
}
static int match_hostname(const char *hostname, const char *match)
{
while (*match) {
const char *h_dot, *m_dot;
int helem_len, melem_len;
h_dot = strchr(hostname, '.');
m_dot = strchr(match, '.');
if (h_dot && m_dot) {
helem_len = h_dot - hostname + 1;
melem_len = m_dot - match + 1;
} else if (!h_dot && !m_dot) {
helem_len = strlen(hostname);
melem_len = strlen(match);
} else
return -1;
if (match_hostname_elem(hostname, helem_len,
match, melem_len))
return -1;
hostname += helem_len;
match += melem_len;
}
if (*hostname)
return -1;
return 0;
}
/* cf. RFC2818 and RFC2459 */
static int match_cert_hostname(struct openconnect_info *vpninfo, X509 *peer_cert)
{
STACK_OF(GENERAL_NAME) *altnames;
X509_NAME *subjname;
ASN1_STRING *subjasn1;
char *subjstr = NULL;
int addrlen = 0;
int i, altdns = 0;
char addrbuf[sizeof(struct in6_addr)];
int ret;
/* Allow GEN_IP in the certificate only if we actually connected
by IP address rather than by name. */
if (inet_pton(AF_INET, vpninfo->hostname, addrbuf) > 0)
addrlen = 4;
else if (inet_pton(AF_INET6, vpninfo->hostname, addrbuf) > 0)
addrlen = 16;
else if (vpninfo->hostname[0] == '[' &&
vpninfo->hostname[strlen(vpninfo->hostname)-1] == ']') {
char *p = &vpninfo->hostname[strlen(vpninfo->hostname)-1];
*p = 0;
if (inet_pton(AF_INET6, vpninfo->hostname + 1, addrbuf) > 0)
addrlen = 16;
*p = ']';
}
altnames = X509_get_ext_d2i(peer_cert, NID_subject_alt_name,
NULL, NULL);
for (i = 0; i < sk_GENERAL_NAME_num(altnames); i++) {
const GENERAL_NAME *this = sk_GENERAL_NAME_value(altnames, i);
if (this->type == GEN_DNS) {
char *str;
int len = ASN1_STRING_to_UTF8((void *)&str, this->d.ia5);
if (len < 0)
continue;
altdns = 1;
/* We don't like names with embedded NUL */
if (strlen(str) != len)
continue;
if (!match_hostname(vpninfo->hostname, str)) {
vpn_progress(vpninfo, PRG_TRACE,
_("Matched DNS altname '%s'\n"),
str);
GENERAL_NAMES_free(altnames);
OPENSSL_free(str);
return 0;
} else {
vpn_progress(vpninfo, PRG_TRACE,
_("No match for altname '%s'\n"),
str);
}
OPENSSL_free(str);
} else if (this->type == GEN_IPADD && addrlen) {
char host[80];
int family;
if (this->d.ip->length == 4) {
family = AF_INET;
} else if (this->d.ip->length == 16) {
family = AF_INET6;
} else {
vpn_progress(vpninfo, PRG_ERR,
_("Certificate has GEN_IPADD altname with bogus length %d\n"),
this->d.ip->length);
continue;
}
/* We only do this for the debug messages */