blob: c906ebb4b49b27e302886aa1c3088879d84f2659 [file] [log] [blame]
/*
* Copyright 2008 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#if HAVE_OPENSSL_SSL_H
#include "webrtc/base/openssladapter.h"
#if defined(WEBRTC_POSIX)
#include <unistd.h>
#endif
// Must be included first before openssl headers.
#include "webrtc/base/win32.h" // NOLINT
#include <openssl/bio.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/opensslv.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#if HAVE_CONFIG_H
#include "config.h"
#endif // HAVE_CONFIG_H
#include "webrtc/base/common.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/openssl.h"
#include "webrtc/base/safe_conversions.h"
#include "webrtc/base/sslroots.h"
#include "webrtc/base/stringutils.h"
#include "webrtc/base/thread.h"
#ifndef OPENSSL_IS_BORINGSSL
// TODO: Use a nicer abstraction for mutex.
#if defined(WEBRTC_WIN)
#define MUTEX_TYPE HANDLE
#define MUTEX_SETUP(x) (x) = CreateMutex(NULL, FALSE, NULL)
#define MUTEX_CLEANUP(x) CloseHandle(x)
#define MUTEX_LOCK(x) WaitForSingleObject((x), INFINITE)
#define MUTEX_UNLOCK(x) ReleaseMutex(x)
#define THREAD_ID GetCurrentThreadId()
#elif defined(WEBRTC_POSIX)
#define MUTEX_TYPE pthread_mutex_t
#define MUTEX_SETUP(x) pthread_mutex_init(&(x), NULL)
#define MUTEX_CLEANUP(x) pthread_mutex_destroy(&(x))
#define MUTEX_LOCK(x) pthread_mutex_lock(&(x))
#define MUTEX_UNLOCK(x) pthread_mutex_unlock(&(x))
#define THREAD_ID pthread_self()
#else
#error You must define mutex operations appropriate for your platform!
#endif
struct CRYPTO_dynlock_value {
MUTEX_TYPE mutex;
};
#endif // #ifndef OPENSSL_IS_BORINGSSL
//////////////////////////////////////////////////////////////////////
// SocketBIO
//////////////////////////////////////////////////////////////////////
static int socket_write(BIO* h, const char* buf, int num);
static int socket_read(BIO* h, char* buf, int size);
static int socket_puts(BIO* h, const char* str);
static long socket_ctrl(BIO* h, int cmd, long arg1, void* arg2);
static int socket_new(BIO* h);
static int socket_free(BIO* data);
// TODO(davidben): This should be const once BoringSSL is assumed.
static BIO_METHOD methods_socket = {
BIO_TYPE_BIO,
"socket",
socket_write,
socket_read,
socket_puts,
0,
socket_ctrl,
socket_new,
socket_free,
NULL,
};
static BIO_METHOD* BIO_s_socket2() { return(&methods_socket); }
static BIO* BIO_new_socket(rtc::AsyncSocket* socket) {
BIO* ret = BIO_new(BIO_s_socket2());
if (ret == NULL) {
return NULL;
}
ret->ptr = socket;
return ret;
}
static int socket_new(BIO* b) {
b->shutdown = 0;
b->init = 1;
b->num = 0; // 1 means socket closed
b->ptr = 0;
return 1;
}
static int socket_free(BIO* b) {
if (b == NULL)
return 0;
return 1;
}
static int socket_read(BIO* b, char* out, int outl) {
if (!out)
return -1;
rtc::AsyncSocket* socket = static_cast<rtc::AsyncSocket*>(b->ptr);
BIO_clear_retry_flags(b);
int result = socket->Recv(out, outl);
if (result > 0) {
return result;
} else if (result == 0) {
b->num = 1;
} else if (socket->IsBlocking()) {
BIO_set_retry_read(b);
}
return -1;
}
static int socket_write(BIO* b, const char* in, int inl) {
if (!in)
return -1;
rtc::AsyncSocket* socket = static_cast<rtc::AsyncSocket*>(b->ptr);
BIO_clear_retry_flags(b);
int result = socket->Send(in, inl);
if (result > 0) {
return result;
} else if (socket->IsBlocking()) {
BIO_set_retry_write(b);
}
return -1;
}
static int socket_puts(BIO* b, const char* str) {
return socket_write(b, str, rtc::checked_cast<int>(strlen(str)));
}
static long socket_ctrl(BIO* b, int cmd, long num, void* ptr) {
RTC_UNUSED(num);
RTC_UNUSED(ptr);
switch (cmd) {
case BIO_CTRL_RESET:
return 0;
case BIO_CTRL_EOF:
return b->num;
case BIO_CTRL_WPENDING:
case BIO_CTRL_PENDING:
return 0;
case BIO_CTRL_FLUSH:
return 1;
default:
return 0;
}
}
/////////////////////////////////////////////////////////////////////////////
// OpenSSLAdapter
/////////////////////////////////////////////////////////////////////////////
namespace rtc {
#ifndef OPENSSL_IS_BORINGSSL
// This array will store all of the mutexes available to OpenSSL.
static MUTEX_TYPE* mutex_buf = NULL;
static void locking_function(int mode, int n, const char * file, int line) {
if (mode & CRYPTO_LOCK) {
MUTEX_LOCK(mutex_buf[n]);
} else {
MUTEX_UNLOCK(mutex_buf[n]);
}
}
static unsigned long id_function() { // NOLINT
// Use old-style C cast because THREAD_ID's type varies with the platform,
// in some cases requiring static_cast, and in others requiring
// reinterpret_cast.
return (unsigned long)THREAD_ID; // NOLINT
}
static CRYPTO_dynlock_value* dyn_create_function(const char* file, int line) {
CRYPTO_dynlock_value* value = new CRYPTO_dynlock_value;
if (!value)
return NULL;
MUTEX_SETUP(value->mutex);
return value;
}
static void dyn_lock_function(int mode, CRYPTO_dynlock_value* l,
const char* file, int line) {
if (mode & CRYPTO_LOCK) {
MUTEX_LOCK(l->mutex);
} else {
MUTEX_UNLOCK(l->mutex);
}
}
static void dyn_destroy_function(CRYPTO_dynlock_value* l,
const char* file, int line) {
MUTEX_CLEANUP(l->mutex);
delete l;
}
#endif // #ifndef OPENSSL_IS_BORINGSSL
VerificationCallback OpenSSLAdapter::custom_verify_callback_ = NULL;
bool OpenSSLAdapter::InitializeSSL(VerificationCallback callback) {
if (!InitializeSSLThread() || !SSL_library_init())
return false;
#if !defined(ADDRESS_SANITIZER) || !defined(WEBRTC_MAC) || defined(WEBRTC_IOS)
// Loading the error strings crashes mac_asan. Omit this debugging aid there.
SSL_load_error_strings();
#endif
ERR_load_BIO_strings();
OpenSSL_add_all_algorithms();
RAND_poll();
custom_verify_callback_ = callback;
return true;
}
bool OpenSSLAdapter::InitializeSSLThread() {
// BoringSSL is doing the locking internally, so the callbacks are not used
// in this case (and are no-ops anyways).
#ifndef OPENSSL_IS_BORINGSSL
mutex_buf = new MUTEX_TYPE[CRYPTO_num_locks()];
if (!mutex_buf)
return false;
for (int i = 0; i < CRYPTO_num_locks(); ++i)
MUTEX_SETUP(mutex_buf[i]);
// we need to cast our id_function to return an unsigned long -- pthread_t is
// a pointer
CRYPTO_set_id_callback(id_function);
CRYPTO_set_locking_callback(locking_function);
CRYPTO_set_dynlock_create_callback(dyn_create_function);
CRYPTO_set_dynlock_lock_callback(dyn_lock_function);
CRYPTO_set_dynlock_destroy_callback(dyn_destroy_function);
#endif // #ifndef OPENSSL_IS_BORINGSSL
return true;
}
bool OpenSSLAdapter::CleanupSSL() {
#ifndef OPENSSL_IS_BORINGSSL
if (!mutex_buf)
return false;
CRYPTO_set_id_callback(NULL);
CRYPTO_set_locking_callback(NULL);
CRYPTO_set_dynlock_create_callback(NULL);
CRYPTO_set_dynlock_lock_callback(NULL);
CRYPTO_set_dynlock_destroy_callback(NULL);
for (int i = 0; i < CRYPTO_num_locks(); ++i)
MUTEX_CLEANUP(mutex_buf[i]);
delete [] mutex_buf;
mutex_buf = NULL;
#endif // #ifndef OPENSSL_IS_BORINGSSL
return true;
}
OpenSSLAdapter::OpenSSLAdapter(AsyncSocket* socket)
: SSLAdapter(socket),
state_(SSL_NONE),
ssl_read_needs_write_(false),
ssl_write_needs_read_(false),
restartable_(false),
ssl_(NULL), ssl_ctx_(NULL),
ssl_mode_(SSL_MODE_TLS),
custom_verification_succeeded_(false) {
}
OpenSSLAdapter::~OpenSSLAdapter() {
Cleanup();
}
void
OpenSSLAdapter::SetMode(SSLMode mode) {
ASSERT(state_ == SSL_NONE);
ssl_mode_ = mode;
}
int
OpenSSLAdapter::StartSSL(const char* hostname, bool restartable) {
if (state_ != SSL_NONE)
return -1;
ssl_host_name_ = hostname;
restartable_ = restartable;
if (socket_->GetState() != Socket::CS_CONNECTED) {
state_ = SSL_WAIT;
return 0;
}
state_ = SSL_CONNECTING;
if (int err = BeginSSL()) {
Error("BeginSSL", err, false);
return err;
}
return 0;
}
int
OpenSSLAdapter::BeginSSL() {
LOG(LS_INFO) << "BeginSSL: " << ssl_host_name_;
ASSERT(state_ == SSL_CONNECTING);
int err = 0;
BIO* bio = NULL;
// First set up the context
if (!ssl_ctx_)
ssl_ctx_ = SetupSSLContext();
if (!ssl_ctx_) {
err = -1;
goto ssl_error;
}
bio = BIO_new_socket(static_cast<AsyncSocketAdapter*>(socket_));
if (!bio) {
err = -1;
goto ssl_error;
}
ssl_ = SSL_new(ssl_ctx_);
if (!ssl_) {
err = -1;
goto ssl_error;
}
SSL_set_app_data(ssl_, this);
SSL_set_bio(ssl_, bio, bio);
SSL_set_mode(ssl_, SSL_MODE_ENABLE_PARTIAL_WRITE |
SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
// the SSL object owns the bio now
bio = NULL;
// Do the connect
err = ContinueSSL();
if (err != 0)
goto ssl_error;
return err;
ssl_error:
Cleanup();
if (bio)
BIO_free(bio);
return err;
}
int
OpenSSLAdapter::ContinueSSL() {
ASSERT(state_ == SSL_CONNECTING);
// Clear the DTLS timer
Thread::Current()->Clear(this, MSG_TIMEOUT);
int code = SSL_connect(ssl_);
switch (SSL_get_error(ssl_, code)) {
case SSL_ERROR_NONE:
if (!SSLPostConnectionCheck(ssl_, ssl_host_name_.c_str())) {
LOG(LS_ERROR) << "TLS post connection check failed";
// make sure we close the socket
Cleanup();
// The connect failed so return -1 to shut down the socket
return -1;
}
state_ = SSL_CONNECTED;
AsyncSocketAdapter::OnConnectEvent(this);
#if 0 // TODO: worry about this
// Don't let ourselves go away during the callbacks
PRefPtr<OpenSSLAdapter> lock(this);
LOG(LS_INFO) << " -- onStreamReadable";
AsyncSocketAdapter::OnReadEvent(this);
LOG(LS_INFO) << " -- onStreamWriteable";
AsyncSocketAdapter::OnWriteEvent(this);
#endif
break;
case SSL_ERROR_WANT_READ:
LOG(LS_VERBOSE) << " -- error want read";
struct timeval timeout;
if (DTLSv1_get_timeout(ssl_, &timeout)) {
int delay = timeout.tv_sec * 1000 + timeout.tv_usec/1000;
Thread::Current()->PostDelayed(delay, this, MSG_TIMEOUT, 0);
}
break;
case SSL_ERROR_WANT_WRITE:
break;
case SSL_ERROR_ZERO_RETURN:
default:
LOG(LS_WARNING) << "ContinueSSL -- error " << code;
return (code != 0) ? code : -1;
}
return 0;
}
void
OpenSSLAdapter::Error(const char* context, int err, bool signal) {
LOG(LS_WARNING) << "OpenSSLAdapter::Error("
<< context << ", " << err << ")";
state_ = SSL_ERROR;
SetError(err);
if (signal)
AsyncSocketAdapter::OnCloseEvent(this, err);
}
void
OpenSSLAdapter::Cleanup() {
LOG(LS_INFO) << "Cleanup";
state_ = SSL_NONE;
ssl_read_needs_write_ = false;
ssl_write_needs_read_ = false;
custom_verification_succeeded_ = false;
if (ssl_) {
SSL_free(ssl_);
ssl_ = NULL;
}
if (ssl_ctx_) {
SSL_CTX_free(ssl_ctx_);
ssl_ctx_ = NULL;
}
// Clear the DTLS timer
Thread::Current()->Clear(this, MSG_TIMEOUT);
}
//
// AsyncSocket Implementation
//
int
OpenSSLAdapter::Send(const void* pv, size_t cb) {
//LOG(LS_INFO) << "OpenSSLAdapter::Send(" << cb << ")";
switch (state_) {
case SSL_NONE:
return AsyncSocketAdapter::Send(pv, cb);
case SSL_WAIT:
case SSL_CONNECTING:
SetError(EWOULDBLOCK);
return SOCKET_ERROR;
case SSL_CONNECTED:
break;
case SSL_ERROR:
default:
return SOCKET_ERROR;
}
// OpenSSL will return an error if we try to write zero bytes
if (cb == 0)
return 0;
ssl_write_needs_read_ = false;
int code = SSL_write(ssl_, pv, checked_cast<int>(cb));
switch (SSL_get_error(ssl_, code)) {
case SSL_ERROR_NONE:
//LOG(LS_INFO) << " -- success";
return code;
case SSL_ERROR_WANT_READ:
//LOG(LS_INFO) << " -- error want read";
ssl_write_needs_read_ = true;
SetError(EWOULDBLOCK);
break;
case SSL_ERROR_WANT_WRITE:
//LOG(LS_INFO) << " -- error want write";
SetError(EWOULDBLOCK);
break;
case SSL_ERROR_ZERO_RETURN:
//LOG(LS_INFO) << " -- remote side closed";
SetError(EWOULDBLOCK);
// do we need to signal closure?
break;
default:
//LOG(LS_INFO) << " -- error " << code;
Error("SSL_write", (code ? code : -1), false);
break;
}
return SOCKET_ERROR;
}
int
OpenSSLAdapter::SendTo(const void* pv, size_t cb, const SocketAddress& addr) {
if (socket_->GetState() == Socket::CS_CONNECTED &&
addr == socket_->GetRemoteAddress()) {
return Send(pv, cb);
}
SetError(ENOTCONN);
return SOCKET_ERROR;
}
int
OpenSSLAdapter::Recv(void* pv, size_t cb) {
//LOG(LS_INFO) << "OpenSSLAdapter::Recv(" << cb << ")";
switch (state_) {
case SSL_NONE:
return AsyncSocketAdapter::Recv(pv, cb);
case SSL_WAIT:
case SSL_CONNECTING:
SetError(EWOULDBLOCK);
return SOCKET_ERROR;
case SSL_CONNECTED:
break;
case SSL_ERROR:
default:
return SOCKET_ERROR;
}
// Don't trust OpenSSL with zero byte reads
if (cb == 0)
return 0;
ssl_read_needs_write_ = false;
int code = SSL_read(ssl_, pv, checked_cast<int>(cb));
switch (SSL_get_error(ssl_, code)) {
case SSL_ERROR_NONE:
//LOG(LS_INFO) << " -- success";
return code;
case SSL_ERROR_WANT_READ:
//LOG(LS_INFO) << " -- error want read";
SetError(EWOULDBLOCK);
break;
case SSL_ERROR_WANT_WRITE:
//LOG(LS_INFO) << " -- error want write";
ssl_read_needs_write_ = true;
SetError(EWOULDBLOCK);
break;
case SSL_ERROR_ZERO_RETURN:
//LOG(LS_INFO) << " -- remote side closed";
SetError(EWOULDBLOCK);
// do we need to signal closure?
break;
default:
//LOG(LS_INFO) << " -- error " << code;
Error("SSL_read", (code ? code : -1), false);
break;
}
return SOCKET_ERROR;
}
int
OpenSSLAdapter::RecvFrom(void* pv, size_t cb, SocketAddress* paddr) {
if (socket_->GetState() == Socket::CS_CONNECTED) {
int ret = Recv(pv, cb);
*paddr = GetRemoteAddress();
return ret;
}
SetError(ENOTCONN);
return SOCKET_ERROR;
}
int
OpenSSLAdapter::Close() {
Cleanup();
state_ = restartable_ ? SSL_WAIT : SSL_NONE;
return AsyncSocketAdapter::Close();
}
Socket::ConnState
OpenSSLAdapter::GetState() const {
//if (signal_close_)
// return CS_CONNECTED;
ConnState state = socket_->GetState();
if ((state == CS_CONNECTED)
&& ((state_ == SSL_WAIT) || (state_ == SSL_CONNECTING)))
state = CS_CONNECTING;
return state;
}
void
OpenSSLAdapter::OnMessage(Message* msg) {
if (MSG_TIMEOUT == msg->message_id) {
LOG(LS_INFO) << "DTLS timeout expired";
DTLSv1_handle_timeout(ssl_);
ContinueSSL();
}
}
void
OpenSSLAdapter::OnConnectEvent(AsyncSocket* socket) {
LOG(LS_INFO) << "OpenSSLAdapter::OnConnectEvent";
if (state_ != SSL_WAIT) {
ASSERT(state_ == SSL_NONE);
AsyncSocketAdapter::OnConnectEvent(socket);
return;
}
state_ = SSL_CONNECTING;
if (int err = BeginSSL()) {
AsyncSocketAdapter::OnCloseEvent(socket, err);
}
}
void
OpenSSLAdapter::OnReadEvent(AsyncSocket* socket) {
//LOG(LS_INFO) << "OpenSSLAdapter::OnReadEvent";
if (state_ == SSL_NONE) {
AsyncSocketAdapter::OnReadEvent(socket);
return;
}
if (state_ == SSL_CONNECTING) {
if (int err = ContinueSSL()) {
Error("ContinueSSL", err);
}
return;
}
if (state_ != SSL_CONNECTED)
return;
// Don't let ourselves go away during the callbacks
//PRefPtr<OpenSSLAdapter> lock(this); // TODO: fix this
if (ssl_write_needs_read_) {
//LOG(LS_INFO) << " -- onStreamWriteable";
AsyncSocketAdapter::OnWriteEvent(socket);
}
//LOG(LS_INFO) << " -- onStreamReadable";
AsyncSocketAdapter::OnReadEvent(socket);
}
void
OpenSSLAdapter::OnWriteEvent(AsyncSocket* socket) {
//LOG(LS_INFO) << "OpenSSLAdapter::OnWriteEvent";
if (state_ == SSL_NONE) {
AsyncSocketAdapter::OnWriteEvent(socket);
return;
}
if (state_ == SSL_CONNECTING) {
if (int err = ContinueSSL()) {
Error("ContinueSSL", err);
}
return;
}
if (state_ != SSL_CONNECTED)
return;
// Don't let ourselves go away during the callbacks
//PRefPtr<OpenSSLAdapter> lock(this); // TODO: fix this
if (ssl_read_needs_write_) {
//LOG(LS_INFO) << " -- onStreamReadable";
AsyncSocketAdapter::OnReadEvent(socket);
}
//LOG(LS_INFO) << " -- onStreamWriteable";
AsyncSocketAdapter::OnWriteEvent(socket);
}
void
OpenSSLAdapter::OnCloseEvent(AsyncSocket* socket, int err) {
LOG(LS_INFO) << "OpenSSLAdapter::OnCloseEvent(" << err << ")";
AsyncSocketAdapter::OnCloseEvent(socket, err);
}
// This code is taken from the "Network Security with OpenSSL"
// sample in chapter 5
bool OpenSSLAdapter::VerifyServerName(SSL* ssl, const char* host,
bool ignore_bad_cert) {
if (!host)
return false;
// Checking the return from SSL_get_peer_certificate here is not strictly
// necessary. With our setup, it is not possible for it to return
// NULL. However, it is good form to check the return.
X509* certificate = SSL_get_peer_certificate(ssl);
if (!certificate)
return false;
// Logging certificates is extremely verbose. So it is disabled by default.
#ifdef LOG_CERTIFICATES
{
LOG(LS_INFO) << "Certificate from server:";
BIO* mem = BIO_new(BIO_s_mem());
X509_print_ex(mem, certificate, XN_FLAG_SEP_CPLUS_SPC, X509_FLAG_NO_HEADER);
BIO_write(mem, "\0", 1);
char* buffer;
BIO_get_mem_data(mem, &buffer);
LOG(LS_INFO) << buffer;
BIO_free(mem);
char* cipher_description =
SSL_CIPHER_description(SSL_get_current_cipher(ssl), NULL, 128);
LOG(LS_INFO) << "Cipher: " << cipher_description;
OPENSSL_free(cipher_description);
}
#endif
bool ok = false;
int extension_count = X509_get_ext_count(certificate);
for (int i = 0; i < extension_count; ++i) {
X509_EXTENSION* extension = X509_get_ext(certificate, i);
int extension_nid = OBJ_obj2nid(X509_EXTENSION_get_object(extension));
if (extension_nid == NID_subject_alt_name) {
const X509V3_EXT_METHOD* meth = X509V3_EXT_get(extension);
if (!meth)
break;
void* ext_str = NULL;
// We assign this to a local variable, instead of passing the address
// directly to ASN1_item_d2i.
// See http://readlist.com/lists/openssl.org/openssl-users/0/4761.html.
unsigned char* ext_value_data = extension->value->data;
const unsigned char **ext_value_data_ptr =
(const_cast<const unsigned char **>(&ext_value_data));
if (meth->it) {
ext_str = ASN1_item_d2i(NULL, ext_value_data_ptr,
extension->value->length,
ASN1_ITEM_ptr(meth->it));
} else {
ext_str = meth->d2i(NULL, ext_value_data_ptr, extension->value->length);
}
STACK_OF(CONF_VALUE)* value = meth->i2v(meth, ext_str, NULL);
// Cast to size_t to be compilable for both OpenSSL and BoringSSL.
for (size_t j = 0; j < static_cast<size_t>(sk_CONF_VALUE_num(value));
++j) {
CONF_VALUE* nval = sk_CONF_VALUE_value(value, j);
// The value for nval can contain wildcards
if (!strcmp(nval->name, "DNS") && string_match(host, nval->value)) {
ok = true;
break;
}
}
sk_CONF_VALUE_pop_free(value, X509V3_conf_free);
value = NULL;
if (meth->it) {
ASN1_item_free(reinterpret_cast<ASN1_VALUE*>(ext_str),
ASN1_ITEM_ptr(meth->it));
} else {
meth->ext_free(ext_str);
}
ext_str = NULL;
}
if (ok)
break;
}
char data[256];
X509_NAME* subject;
if (!ok
&& ((subject = X509_get_subject_name(certificate)) != NULL)
&& (X509_NAME_get_text_by_NID(subject, NID_commonName,
data, sizeof(data)) > 0)) {
data[sizeof(data)-1] = 0;
if (_stricmp(data, host) == 0)
ok = true;
}
X509_free(certificate);
// This should only ever be turned on for debugging and development.
if (!ok && ignore_bad_cert) {
LOG(LS_WARNING) << "TLS certificate check FAILED. "
<< "Allowing connection anyway.";
ok = true;
}
return ok;
}
bool OpenSSLAdapter::SSLPostConnectionCheck(SSL* ssl, const char* host) {
bool ok = VerifyServerName(ssl, host, ignore_bad_cert());
if (ok) {
ok = (SSL_get_verify_result(ssl) == X509_V_OK ||
custom_verification_succeeded_);
}
if (!ok && ignore_bad_cert()) {
LOG(LS_INFO) << "Other TLS post connection checks failed.";
ok = true;
}
return ok;
}
#if _DEBUG
// We only use this for tracing and so it is only needed in debug mode
void
OpenSSLAdapter::SSLInfoCallback(const SSL* s, int where, int ret) {
const char* str = "undefined";
int w = where & ~SSL_ST_MASK;
if (w & SSL_ST_CONNECT) {
str = "SSL_connect";
} else if (w & SSL_ST_ACCEPT) {
str = "SSL_accept";
}
if (where & SSL_CB_LOOP) {
LOG(LS_INFO) << str << ":" << SSL_state_string_long(s);
} else if (where & SSL_CB_ALERT) {
str = (where & SSL_CB_READ) ? "read" : "write";
LOG(LS_INFO) << "SSL3 alert " << str
<< ":" << SSL_alert_type_string_long(ret)
<< ":" << SSL_alert_desc_string_long(ret);
} else if (where & SSL_CB_EXIT) {
if (ret == 0) {
LOG(LS_INFO) << str << ":failed in " << SSL_state_string_long(s);
} else if (ret < 0) {
LOG(LS_INFO) << str << ":error in " << SSL_state_string_long(s);
}
}
}
#endif // _DEBUG
int
OpenSSLAdapter::SSLVerifyCallback(int ok, X509_STORE_CTX* store) {
#if _DEBUG
if (!ok) {
char data[256];
X509* cert = X509_STORE_CTX_get_current_cert(store);
int depth = X509_STORE_CTX_get_error_depth(store);
int err = X509_STORE_CTX_get_error(store);
LOG(LS_INFO) << "Error with certificate at depth: " << depth;
X509_NAME_oneline(X509_get_issuer_name(cert), data, sizeof(data));
LOG(LS_INFO) << " issuer = " << data;
X509_NAME_oneline(X509_get_subject_name(cert), data, sizeof(data));
LOG(LS_INFO) << " subject = " << data;
LOG(LS_INFO) << " err = " << err
<< ":" << X509_verify_cert_error_string(err);
}
#endif
// Get our stream pointer from the store
SSL* ssl = reinterpret_cast<SSL*>(
X509_STORE_CTX_get_ex_data(store,
SSL_get_ex_data_X509_STORE_CTX_idx()));
OpenSSLAdapter* stream =
reinterpret_cast<OpenSSLAdapter*>(SSL_get_app_data(ssl));
if (!ok && custom_verify_callback_) {
void* cert =
reinterpret_cast<void*>(X509_STORE_CTX_get_current_cert(store));
if (custom_verify_callback_(cert)) {
stream->custom_verification_succeeded_ = true;
LOG(LS_INFO) << "validated certificate using custom callback";
ok = true;
}
}
// Should only be used for debugging and development.
if (!ok && stream->ignore_bad_cert()) {
LOG(LS_WARNING) << "Ignoring cert error while verifying cert chain";
ok = 1;
}
return ok;
}
bool OpenSSLAdapter::ConfigureTrustedRootCertificates(SSL_CTX* ctx) {
// Add the root cert that we care about to the SSL context
int count_of_added_certs = 0;
for (int i = 0; i < ARRAY_SIZE(kSSLCertCertificateList); i++) {
const unsigned char* cert_buffer = kSSLCertCertificateList[i];
size_t cert_buffer_len = kSSLCertCertificateSizeList[i];
X509* cert = d2i_X509(NULL, &cert_buffer,
checked_cast<long>(cert_buffer_len));
if (cert) {
int return_value = X509_STORE_add_cert(SSL_CTX_get_cert_store(ctx), cert);
if (return_value == 0) {
LOG(LS_WARNING) << "Unable to add certificate.";
} else {
count_of_added_certs++;
}
X509_free(cert);
}
}
return count_of_added_certs > 0;
}
SSL_CTX*
OpenSSLAdapter::SetupSSLContext() {
SSL_CTX* ctx = SSL_CTX_new(ssl_mode_ == SSL_MODE_DTLS ?
DTLSv1_client_method() : TLSv1_client_method());
if (ctx == NULL) {
unsigned long error = ERR_get_error(); // NOLINT: type used by OpenSSL.
LOG(LS_WARNING) << "SSL_CTX creation failed: "
<< '"' << ERR_reason_error_string(error) << "\" "
<< "(error=" << error << ')';
return NULL;
}
if (!ConfigureTrustedRootCertificates(ctx)) {
SSL_CTX_free(ctx);
return NULL;
}
#ifdef _DEBUG
SSL_CTX_set_info_callback(ctx, SSLInfoCallback);
#endif
SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, SSLVerifyCallback);
SSL_CTX_set_verify_depth(ctx, 4);
SSL_CTX_set_cipher_list(ctx, "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH");
if (ssl_mode_ == SSL_MODE_DTLS) {
SSL_CTX_set_read_ahead(ctx, 1);
}
return ctx;
}
} // namespace rtc
#endif // HAVE_OPENSSL_SSL_H