// Copyright (c) 2008-2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/socket/ssl_client_socket_mac.h"
#include <CoreServices/CoreServices.h>
#include "base/scoped_cftyperef.h"
#include "base/singleton.h"
#include "base/string_util.h"
#include "net/base/cert_verifier.h"
#include "net/base/io_buffer.h"
#include "net/base/load_log.h"
#include "net/base/net_errors.h"
#include "net/base/ssl_info.h"
// Welcome to Mac SSL. We've been waiting for you.
//
// The Mac SSL implementation is, like the Windows and NSS implementations, a
// giant state machine. This design constraint is due to the asynchronous nature
// of our underlying transport mechanism. We can call down to read/write on the
// network, but what happens is that either it completes immediately or returns
// saying that we'll get a callback sometime in the future. In that case, we
// have to return to our caller but pick up where we left off when we
// resume. Thus the fun.
//
// On Windows, we use Security Contexts, which are driven by us. We fetch data
// from the network, we call the context to decrypt the data, and so on. On the
// Mac, however, we provide Secure Transport with callbacks to get data from the
// network, and it calls us back to fetch the data from the network for
// it. Therefore, there are different sets of states in our respective state
// machines, fewer on the Mac because Secure Transport keeps a lot of its own
// state. The discussion about what each of the states means lives in comments
// in the DoLoop() function.
//
// Secure Transport is designed for use by either blocking or non-blocking
// network I/O. If, for example, you called SSLRead() to fetch data, Secure
// Transport will, unless it has some cached data, issue a read to your network
// callback read function to fetch it some more encrypted data. It's expecting
// one of two things. If your function is hooked up to a blocking source, then
// it'll block pending receipt of the data from the other end. That's fine, as
// when you return with the data, Secure Transport will do its thing. On the
// other hand, suppose that your socket is non-blocking and tells your function
// that it would block. Then you let Secure Transport know, and it'll tell the
// original caller that it would have blocked and that they need to call it
// "later."
//
// When's "later," though? We have fully-asynchronous networking, so we get a
// callback when our data's ready. But Secure Transport has no way for us to
// tell it that data has arrived, so we must re-execute the call that triggered
// the I/O (we rely on our state machine to do this). When we do so Secure
// Transport will ask once again for the data. Chances are that it'll be the
// same request as the previous time, but that's not actually guaranteed. But as
// long as we buffer what we have and keep track of where we were, it works
// quite well.
//
// Except for network writes. They shoot this plan straight to hell.
//
// Faking a blocking connection with an asynchronous connection (theoretically
// more powerful) simply doesn't work for writing. Suppose that Secure Transport
// requests a write of data to the network. With blocking I/O, we'd just block
// until the write completed, and with non-blocking I/O we'd know how many bytes
// we wrote before we would have blocked. But with the asynchronous I/O, the
// transport underneath us can tell us that it'll let us know sometime "later"
// whether or not things succeeded, and how many bytes were written. What do we
// return to Secure Transport? We can't return a byte count, but we can't return
// "later" as we're not guaranteed to be called in the future with the same data
// to write.
//
// So, like in any good relationship, we're forced to lie. Whenever Secure
// Transport asks for data to be written, we take it all and lie about it always
// being written. We spin in a loop (see SSLWriteCallback() and
// OnTransportWriteComplete()) independent of the main state machine writing
// the data to the network, and get the data out. The main consequence of this
// independence from the state machine is that we require a full-duplex
// transport underneath us since we can't use it to keep our reading and
// writing straight. Fortunately, the NSS implementation also has this issue
// to deal with, so we share the same Libevent-based full-duplex TCP socket.
//
// A side comment on return values might be in order. Those who haven't taken
// the time to read the documentation (ahem, header comments) in our various
// files might be a bit surprised to see result values being treated as both
// lengths and errors. Like Shimmer, they are both. In both the case of
// immediate results as well as results returned in callbacks, a negative return
// value indicates an error, a zero return value indicates end-of-stream (for
// reads), and a positive return value indicates the number of bytes read or
// written. Thus, many functions start off with |if (result < 0) return
// result;|. That gets the error condition out of the way, and from that point
// forward the result can be treated as a length.
namespace net {
namespace {
// Declarations needed to call the 10.5.7 and later SSLSetSessionOption()
// function when building with the 10.5.0 SDK.
typedef enum {
kSSLSessionOptionBreakOnServerAuthFlag
} SSLSetSessionOptionType;
enum {
errSSLServerAuthCompletedFlag = -9841
};
// When compiled against the Mac OS X 10.5 SDK, define symbolic constants for
// cipher suites added in Mac OS X 10.6.
#if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_5
enum {
// ECC cipher suites from RFC 4492.
TLS_ECDH_ECDSA_WITH_NULL_SHA = 0xC001,
TLS_ECDH_ECDSA_WITH_RC4_128_SHA = 0xC002,
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA = 0xC003,
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA = 0xC004,
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA = 0xC005,
TLS_ECDHE_ECDSA_WITH_NULL_SHA = 0xC006,
TLS_ECDHE_ECDSA_WITH_RC4_128_SHA = 0xC007,
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA = 0xC008,
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA = 0xC009,
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA = 0xC00A,
TLS_ECDH_RSA_WITH_NULL_SHA = 0xC00B,
TLS_ECDH_RSA_WITH_RC4_128_SHA = 0xC00C,
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA = 0xC00D,
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA = 0xC00E,
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA = 0xC00F,
TLS_ECDHE_RSA_WITH_NULL_SHA = 0xC010,
TLS_ECDHE_RSA_WITH_RC4_128_SHA = 0xC011,
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA = 0xC012,
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA = 0xC013,
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA = 0xC014,
TLS_ECDH_anon_WITH_NULL_SHA = 0xC015,
TLS_ECDH_anon_WITH_RC4_128_SHA = 0xC016,
TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA = 0xC017,
TLS_ECDH_anon_WITH_AES_128_CBC_SHA = 0xC018,
TLS_ECDH_anon_WITH_AES_256_CBC_SHA = 0xC019,
};
#endif
typedef OSStatus (*SSLSetSessionOptionFuncPtr)(SSLContextRef,
SSLSetSessionOptionType,
Boolean);
// For an explanation of the Mac OS X error codes, please refer to:
// http://developer.apple.com/mac/library/documentation/Security/Reference/secureTransportRef/Reference/reference.html
int NetErrorFromOSStatus(OSStatus status) {
switch (status) {
case errSSLWouldBlock:
return ERR_IO_PENDING;
case errSSLBadCipherSuite:
case errSSLBadConfiguration:
return ERR_INVALID_ARGUMENT;
case errSSLClosedNoNotify:
return ERR_CONNECTION_RESET;
case errSSLClosedAbort:
return ERR_CONNECTION_ABORTED;
case errSSLInternal:
return ERR_UNEXPECTED;
case errSSLCrypto:
case errSSLFatalAlert:
case errSSLIllegalParam: // Received an illegal_parameter alert.
case errSSLPeerUnexpectedMsg: // Received an unexpected_message alert.
case errSSLProtocol:
case errSSLPeerHandshakeFail: // Received a handshake_failure alert.
case errSSLConnectionRefused:
return ERR_SSL_PROTOCOL_ERROR;
case errSSLHostNameMismatch:
return ERR_CERT_COMMON_NAME_INVALID;
case errSSLCertExpired:
case errSSLCertNotYetValid:
return ERR_CERT_DATE_INVALID;
case errSSLNoRootCert:
case errSSLUnknownRootCert:
return ERR_CERT_AUTHORITY_INVALID;
case errSSLXCertChainInvalid:
case errSSLBadCert:
return ERR_CERT_INVALID;
case errSSLPeerCertRevoked:
return ERR_CERT_REVOKED;
case errSSLClosedGraceful:
case noErr:
return OK;
case errSSLBadRecordMac:
case errSSLBufferOverflow:
case errSSLDecryptionFail:
case errSSLModuleAttach:
case errSSLNegotiation:
case errSSLRecordOverflow:
case errSSLSessionNotFound:
default:
LOG(WARNING) << "Unknown error " << status <<
" mapped to net::ERR_FAILED";
return ERR_FAILED;
}
}
OSStatus OSStatusFromNetError(int net_error) {
switch (net_error) {
case ERR_IO_PENDING:
return errSSLWouldBlock;
case ERR_INTERNET_DISCONNECTED:
case ERR_TIMED_OUT:
case ERR_CONNECTION_ABORTED:
case ERR_CONNECTION_RESET:
case ERR_CONNECTION_REFUSED:
case ERR_ADDRESS_UNREACHABLE:
case ERR_ADDRESS_INVALID:
return errSSLClosedAbort;
case ERR_UNEXPECTED:
return errSSLInternal;
case ERR_INVALID_ARGUMENT:
return paramErr;
case OK:
return noErr;
default:
LOG(WARNING) << "Unknown error " << net_error <<
" mapped to paramErr";
return paramErr;
}
}
// Converts from a cipher suite to its key size. If the suite is marked with a
// **, it's not actually implemented in Secure Transport and won't be returned
// (but we'll code for it anyway). The reference here is
// http://www.opensource.apple.com/darwinsource/10.5.5/libsecurity_ssl-32463/lib/cipherSpecs.c
// Seriously, though, there has to be an API for this, but I can't find one.
// Anybody?
int KeySizeOfCipherSuite(SSLCipherSuite suite) {
switch (suite) {
// SSL 2 only
case SSL_RSA_WITH_DES_CBC_MD5:
return 56;
case SSL_RSA_WITH_3DES_EDE_CBC_MD5:
return 112;
case SSL_RSA_WITH_RC2_CBC_MD5:
case SSL_RSA_WITH_IDEA_CBC_MD5: // **
return 128;
case SSL_NO_SUCH_CIPHERSUITE: // **
return 0;
// SSL 2, 3, TLS
case SSL_NULL_WITH_NULL_NULL:
case SSL_RSA_WITH_NULL_MD5:
case SSL_RSA_WITH_NULL_SHA: // **
case SSL_FORTEZZA_DMS_WITH_NULL_SHA: // **
case TLS_ECDH_ECDSA_WITH_NULL_SHA:
case TLS_ECDHE_ECDSA_WITH_NULL_SHA:
case TLS_ECDH_RSA_WITH_NULL_SHA:
case TLS_ECDHE_RSA_WITH_NULL_SHA:
case TLS_ECDH_anon_WITH_NULL_SHA:
return 0;
case SSL_RSA_EXPORT_WITH_RC4_40_MD5:
case SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5:
case SSL_RSA_EXPORT_WITH_DES40_CBC_SHA:
case SSL_DH_DSS_EXPORT_WITH_DES40_CBC_SHA: // **
case SSL_DH_RSA_EXPORT_WITH_DES40_CBC_SHA: // **
case SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA:
case SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA:
case SSL_DH_anon_EXPORT_WITH_RC4_40_MD5:
case SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA:
return 40;
case SSL_RSA_WITH_DES_CBC_SHA:
case SSL_DH_DSS_WITH_DES_CBC_SHA: // **
case SSL_DH_RSA_WITH_DES_CBC_SHA: // **
case SSL_DHE_DSS_WITH_DES_CBC_SHA:
case SSL_DHE_RSA_WITH_DES_CBC_SHA:
case SSL_DH_anon_WITH_DES_CBC_SHA:
return 56;
case SSL_FORTEZZA_DMS_WITH_FORTEZZA_CBC_SHA: // **
return 80;
case SSL_RSA_WITH_3DES_EDE_CBC_SHA:
case SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA: // **
case SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA: // **
case SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA:
case SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA:
case SSL_DH_anon_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA:
return 112;
case SSL_RSA_WITH_RC4_128_MD5:
case SSL_RSA_WITH_RC4_128_SHA:
case SSL_RSA_WITH_IDEA_CBC_SHA: // **
case SSL_DH_anon_WITH_RC4_128_MD5:
case TLS_ECDH_ECDSA_WITH_RC4_128_SHA:
case TLS_ECDHE_ECDSA_WITH_RC4_128_SHA:
case TLS_ECDH_RSA_WITH_RC4_128_SHA:
case TLS_ECDHE_RSA_WITH_RC4_128_SHA:
case TLS_ECDH_anon_WITH_RC4_128_SHA:
return 128;
// TLS AES options (see RFC 3268 and RFC 4492)
case TLS_RSA_WITH_AES_128_CBC_SHA:
case TLS_DH_DSS_WITH_AES_128_CBC_SHA: // **
case TLS_DH_RSA_WITH_AES_128_CBC_SHA: // **
case TLS_DHE_DSS_WITH_AES_128_CBC_SHA:
case TLS_DHE_RSA_WITH_AES_128_CBC_SHA:
case TLS_DH_anon_WITH_AES_128_CBC_SHA:
case TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA:
case TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA:
case TLS_ECDH_RSA_WITH_AES_128_CBC_SHA:
case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:
case TLS_ECDH_anon_WITH_AES_128_CBC_SHA:
return 128;
case TLS_RSA_WITH_AES_256_CBC_SHA:
case TLS_DH_DSS_WITH_AES_256_CBC_SHA: // **
case TLS_DH_RSA_WITH_AES_256_CBC_SHA: // **
case TLS_DHE_DSS_WITH_AES_256_CBC_SHA:
case TLS_DHE_RSA_WITH_AES_256_CBC_SHA:
case TLS_DH_anon_WITH_AES_256_CBC_SHA:
case TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA:
case TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA:
case TLS_ECDH_RSA_WITH_AES_256_CBC_SHA:
case TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
case TLS_ECDH_anon_WITH_AES_256_CBC_SHA:
return 256;
default:
return -1;
}
}
// Whitelist the cipher suites we want to enable. We disable the following
// cipher suites.
// - Null encryption cipher suites.
// - Weak cipher suites: < 80 bits of security strength.
// - FORTEZZA cipher suites (obsolete).
// - IDEA cipher suites (RFC 5469 explains why).
// - Anonymous cipher suites.
//
// Why don't we use a blacklist? A blacklist that isn't updated for a new
// Mac OS X release is a potential security issue because the new release
// may have new null encryption or anonymous cipher suites, whereas a
// whitelist that isn't updated for a new Mac OS X release just means we
// won't support any new cipher suites in that release.
bool ShouldEnableCipherSuite(SSLCipherSuite suite) {
switch (suite) {
case SSL_RSA_WITH_3DES_EDE_CBC_MD5:
case SSL_RSA_WITH_RC2_CBC_MD5:
case SSL_RSA_WITH_3DES_EDE_CBC_SHA:
case SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA: // **
case SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA: // **
case SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA:
case SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA:
case TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA:
case SSL_RSA_WITH_RC4_128_MD5:
case SSL_RSA_WITH_RC4_128_SHA:
case TLS_ECDH_ECDSA_WITH_RC4_128_SHA:
case TLS_ECDHE_ECDSA_WITH_RC4_128_SHA:
case TLS_ECDH_RSA_WITH_RC4_128_SHA:
case TLS_ECDHE_RSA_WITH_RC4_128_SHA:
case TLS_RSA_WITH_AES_128_CBC_SHA:
case TLS_DH_DSS_WITH_AES_128_CBC_SHA: // **
case TLS_DH_RSA_WITH_AES_128_CBC_SHA: // **
case TLS_DHE_DSS_WITH_AES_128_CBC_SHA:
case TLS_DHE_RSA_WITH_AES_128_CBC_SHA:
case TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA:
case TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA:
case TLS_ECDH_RSA_WITH_AES_128_CBC_SHA:
case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:
case TLS_RSA_WITH_AES_256_CBC_SHA:
case TLS_DH_DSS_WITH_AES_256_CBC_SHA: // **
case TLS_DH_RSA_WITH_AES_256_CBC_SHA: // **
case TLS_DHE_DSS_WITH_AES_256_CBC_SHA:
case TLS_DHE_RSA_WITH_AES_256_CBC_SHA:
case TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA:
case TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA:
case TLS_ECDH_RSA_WITH_AES_256_CBC_SHA:
case TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
return true;
default:
return false;
}
}
// Returns the server's certificate. The caller must release a reference
// to the return value when done. Returns NULL on failure.
X509Certificate* GetServerCert(SSLContextRef ssl_context) {
CFArrayRef certs;
OSStatus status = SSLCopyPeerCertificates(ssl_context, &certs);
// SSLCopyPeerCertificates may succeed but return a null |certs|
// (if we're using an anonymous cipher suite or if we call it
// before the certificate message has arrived and been parsed).
if (status != noErr || !certs)
return NULL;
scoped_cftyperef<CFArrayRef> scoped_certs(certs);
DCHECK_GT(CFArrayGetCount(certs), 0);
SecCertificateRef server_cert = static_cast<SecCertificateRef>(
const_cast<void*>(CFArrayGetValueAtIndex(certs, 0)));
CFRetain(server_cert);
X509Certificate *x509_cert = X509Certificate::CreateFromHandle(
server_cert, X509Certificate::SOURCE_FROM_NETWORK);
if (!x509_cert)
return NULL;
// Add each of the intermediate certificates in the server's chain to the
// server's X509Certificate object. This makes them available to
// X509Certificate::Verify() for chain building.
// TODO(wtc): Since X509Certificate::CreateFromHandle may return a cached
// X509Certificate object, we may be adding intermediate CA certificates to
// it repeatedly!
CFIndex certs_length = CFArrayGetCount(certs);
for (CFIndex i = 1; i < certs_length; ++i) {
SecCertificateRef cert_ref = reinterpret_cast<SecCertificateRef>(
const_cast<void*>(CFArrayGetValueAtIndex(certs, i)));
CFRetain(cert_ref);
x509_cert->AddIntermediateCertificate(cert_ref);
}
return x509_cert;
}
// A class that wraps an array of enabled cipher suites that can be passed to
// SSLSetEnabledCiphers.
//
// Used as a singleton.
class EnabledCipherSuites {
public:
EnabledCipherSuites();
const SSLCipherSuite* ciphers() const {
return ciphers_.empty() ? NULL : &ciphers_[0];
}
size_t num_ciphers() const { return ciphers_.size(); }
private:
std::vector<SSLCipherSuite> ciphers_;
DISALLOW_COPY_AND_ASSIGN(EnabledCipherSuites);
};
EnabledCipherSuites::EnabledCipherSuites() {
SSLContextRef ssl_context;
OSStatus status = SSLNewContext(false, &ssl_context);
if (status != noErr)
return;
size_t num_supported_ciphers;
status = SSLGetNumberSupportedCiphers(ssl_context, &num_supported_ciphers);
if (status != noErr) {
SSLDisposeContext(ssl_context);
return;
}
DCHECK_NE(num_supported_ciphers, 0U);
std::vector<SSLCipherSuite> supported_ciphers(num_supported_ciphers);
status = SSLGetSupportedCiphers(ssl_context, &supported_ciphers[0],
&num_supported_ciphers);
SSLDisposeContext(ssl_context);
if (status != noErr)
return;
for (size_t i = 0; i < num_supported_ciphers; ++i) {
if (ShouldEnableCipherSuite(supported_ciphers[i]))
ciphers_.push_back(supported_ciphers[i]);
}
}
} // namespace
//-----------------------------------------------------------------------------
SSLClientSocketMac::SSLClientSocketMac(ClientSocket* transport_socket,
const std::string& hostname,
const SSLConfig& ssl_config)
: handshake_io_callback_(this, &SSLClientSocketMac::OnHandshakeIOComplete),
transport_read_callback_(this,
&SSLClientSocketMac::OnTransportReadComplete),
transport_write_callback_(this,
&SSLClientSocketMac::OnTransportWriteComplete),
transport_(transport_socket),
hostname_(hostname),
ssl_config_(ssl_config),
user_connect_callback_(NULL),
user_read_callback_(NULL),
user_write_callback_(NULL),
user_read_buf_len_(0),
user_write_buf_len_(0),
next_handshake_state_(STATE_NONE),
completed_handshake_(false),
handshake_interrupted_(false),
ssl_context_(NULL),
pending_send_error_(OK) {
}
SSLClientSocketMac::~SSLClientSocketMac() {
Disconnect();
}
int SSLClientSocketMac::Connect(CompletionCallback* callback,
LoadLog* load_log) {
DCHECK(transport_.get());
DCHECK(next_handshake_state_ == STATE_NONE);
DCHECK(!user_connect_callback_);
LoadLog::BeginEvent(load_log, LoadLog::TYPE_SSL_CONNECT);
int rv = InitializeSSLContext();
if (rv != OK) {
LoadLog::EndEvent(load_log, LoadLog::TYPE_SSL_CONNECT);
return rv;
}
next_handshake_state_ = STATE_HANDSHAKE_START;
rv = DoHandshakeLoop(OK);
if (rv == ERR_IO_PENDING) {
load_log_ = load_log;
user_connect_callback_ = callback;
} else {
LoadLog::EndEvent(load_log, LoadLog::TYPE_SSL_CONNECT);
}
return rv;
}
void SSLClientSocketMac::Disconnect() {
completed_handshake_ = false;
if (ssl_context_) {
SSLClose(ssl_context_);
SSLDisposeContext(ssl_context_);
ssl_context_ = NULL;
}
// Shut down anything that may call us back.
verifier_.reset();
transport_->Disconnect();
}
bool SSLClientSocketMac::IsConnected() const {
// Ideally, we should also check if we have received the close_notify alert
// message from the server, and return false in that case. We're not doing
// that, so this function may return a false positive. Since the upper
// layer (HttpNetworkTransaction) needs to handle a persistent connection
// closed by the server when we send a request anyway, a false positive in
// exchange for simpler code is a good trade-off.
return completed_handshake_ && transport_->IsConnected();
}
bool SSLClientSocketMac::IsConnectedAndIdle() const {
// Unlike IsConnected, this method doesn't return a false positive.
//
// Strictly speaking, we should check if we have received the close_notify
// alert message from the server, and return false in that case. Although
// the close_notify alert message means EOF in the SSL layer, it is just
// bytes to the transport layer below, so transport_->IsConnectedAndIdle()
// returns the desired false when we receive close_notify.
return completed_handshake_ && transport_->IsConnectedAndIdle();
}
int SSLClientSocketMac::GetPeerName(struct sockaddr* name, socklen_t* namelen) {
return transport_->GetPeerName(name, namelen);
}
int SSLClientSocketMac::Read(IOBuffer* buf, int buf_len,
CompletionCallback* callback) {
DCHECK(completed_handshake_);
DCHECK(!user_read_callback_);
DCHECK(!user_read_buf_);
user_read_buf_ = buf;
user_read_buf_len_ = buf_len;
int rv = DoPayloadRead();
if (rv == ERR_IO_PENDING) {
user_read_callback_ = callback;
} else {
user_read_buf_ = NULL;
user_read_buf_len_ = 0;
}
return rv;
}
int SSLClientSocketMac::Write(IOBuffer* buf, int buf_len,
CompletionCallback* callback) {
DCHECK(completed_handshake_);
DCHECK(!user_write_callback_);
DCHECK(!user_write_buf_);
user_write_buf_ = buf;
user_write_buf_len_ = buf_len;
int rv = DoPayloadWrite();
if (rv == ERR_IO_PENDING) {
user_write_callback_ = callback;
} else {
user_write_buf_ = NULL;
user_write_buf_len_ = 0;
}
return rv;
}
bool SSLClientSocketMac::SetReceiveBufferSize(int32 size) {
return transport_->SetReceiveBufferSize(size);
}
bool SSLClientSocketMac::SetSendBufferSize(int32 size) {
return transport_->SetSendBufferSize(size);
}
void SSLClientSocketMac::GetSSLInfo(SSLInfo* ssl_info) {
ssl_info->Reset();
if (!server_cert_) {
NOTREACHED();
return;
}
// set cert
ssl_info->cert = server_cert_;
// update status
ssl_info->cert_status = server_cert_verify_result_.cert_status;
// security info
SSLCipherSuite suite;
OSStatus status = SSLGetNegotiatedCipher(ssl_context_, &suite);
if (!status)
ssl_info->security_bits = KeySizeOfCipherSuite(suite);
}
void SSLClientSocketMac::GetSSLCertRequestInfo(
SSLCertRequestInfo* cert_request_info) {
// TODO(wtc): implement this.
}
SSLClientSocket::NextProtoStatus
SSLClientSocketMac::GetNextProto(std::string* proto) {
proto->clear();
return kNextProtoUnsupported;
}
int SSLClientSocketMac::InitializeSSLContext() {
OSStatus status = noErr;
status = SSLNewContext(false, &ssl_context_);
if (status)
return NetErrorFromOSStatus(status);
status = SSLSetProtocolVersionEnabled(ssl_context_,
kSSLProtocol2,
ssl_config_.ssl2_enabled);
if (status)
return NetErrorFromOSStatus(status);
status = SSLSetProtocolVersionEnabled(ssl_context_,
kSSLProtocol3,
ssl_config_.ssl3_enabled);
if (status)
return NetErrorFromOSStatus(status);
status = SSLSetProtocolVersionEnabled(ssl_context_,
kTLSProtocol1,
ssl_config_.tls1_enabled);
if (status)
return NetErrorFromOSStatus(status);
const EnabledCipherSuites* enabled_ciphers =
Singleton<EnabledCipherSuites>::get();
status = SSLSetEnabledCiphers(ssl_context_, enabled_ciphers->ciphers(),
enabled_ciphers->num_ciphers());
if (status)
return NetErrorFromOSStatus(status);
status = SSLSetIOFuncs(ssl_context_, SSLReadCallback, SSLWriteCallback);
if (status)
return NetErrorFromOSStatus(status);
status = SSLSetConnection(ssl_context_, this);
if (status)
return NetErrorFromOSStatus(status);
// Disable certificate verification within Secure Transport; we'll
// be handling that ourselves.
status = SSLSetEnableCertVerify(ssl_context_, false);
if (status)
return NetErrorFromOSStatus(status);
// SSLSetSessionOption() was introduced in Mac OS X 10.5.7. It allows us
// to perform certificate validation during the handshake, which is
// required in order to properly enable session resumption.
//
// With the kSSLSessionOptionBreakOnServerAuth option set, SSLHandshake()
// will return errSSLServerAuthCompleted after receiving the server's
// Certificate during the handshake. That gives us an opportunity to verify
// the server certificate and then re-enter that handshake (assuming the
// certificate successfully validated).
//
// If SSLSetSessionOption() is not present, we do not enable session
// resumption, because in that case we are verifying the server's certificate
// after the handshake completes (but before any application data is
// exchanged). If we were to enable session resumption in this situation,
// the session would be cached before we verified the certificate, leaving
// the potential for a session in which the certificate failed to validate
// to still be able to be resumed.
CFBundleRef bundle =
CFBundleGetBundleWithIdentifier(CFSTR("com.apple.security"));
if (bundle) {
SSLSetSessionOptionFuncPtr ssl_set_session_options =
reinterpret_cast<SSLSetSessionOptionFuncPtr>(
CFBundleGetFunctionPointerForName(bundle,
CFSTR("SSLSetSessionOption")));
if (ssl_set_session_options) {
status = ssl_set_session_options(ssl_context_,
kSSLSessionOptionBreakOnServerAuthFlag,
true);
if (status)
return NetErrorFromOSStatus(status);
// Concatenate the hostname and peer address to use as the peer ID. To
// resume a session, we must connect to the same server on the same port
// using the same hostname (i.e., localhost and 127.0.0.1 are considered
// different peers, which puts us through certificate validation again
// and catches hostname/certificate name mismatches.
struct sockaddr_storage addr;
socklen_t addr_length = sizeof(struct sockaddr_storage);
memset(&addr, 0, sizeof(addr));
if (!transport_->GetPeerName(reinterpret_cast<struct sockaddr*>(&addr),
&addr_length)) {
// Assemble the socket hostname and address into a single buffer.
std::vector<char> peer_id(hostname_.begin(), hostname_.end());
peer_id.insert(peer_id.end(), reinterpret_cast<char*>(&addr),
reinterpret_cast<char*>(&addr) + addr_length);
// SSLSetPeerID() treats peer_id as a binary blob, and makes its
// own copy.
status = SSLSetPeerID(ssl_context_, &peer_id[0], peer_id.size());
if (status)
return NetErrorFromOSStatus(status);
}
}
}
return OK;
}
void SSLClientSocketMac::DoConnectCallback(int rv) {
DCHECK(rv != ERR_IO_PENDING);
DCHECK(user_connect_callback_);
DCHECK(next_handshake_state_ == STATE_NONE);
CompletionCallback* c = user_connect_callback_;
user_connect_callback_ = NULL;
c->Run(rv > OK ? OK : rv);
}
void SSLClientSocketMac::DoReadCallback(int rv) {
DCHECK(rv != ERR_IO_PENDING);
DCHECK(user_read_callback_);
// Since Run may result in Read being called, clear user_read_callback_ up
// front.
CompletionCallback* c = user_read_callback_;
user_read_callback_ = NULL;
user_read_buf_ = NULL;
user_read_buf_len_ = 0;
c->Run(rv);
}
void SSLClientSocketMac::DoWriteCallback(int rv) {
DCHECK(rv != ERR_IO_PENDING);
DCHECK(user_write_callback_);
// Since Run may result in Write being called, clear user_write_callback_ up
// front.
CompletionCallback* c = user_write_callback_;
user_write_callback_ = NULL;
user_write_buf_ = NULL;
user_write_buf_len_ = 0;
c->Run(rv);
}
void SSLClientSocketMac::OnHandshakeIOComplete(int result) {
DCHECK(next_handshake_state_ != STATE_NONE);
int rv = DoHandshakeLoop(result);
if (rv != ERR_IO_PENDING) {
LoadLog::EndEvent(load_log_, LoadLog::TYPE_SSL_CONNECT);
load_log_ = NULL;
DoConnectCallback(rv);
}
}
void SSLClientSocketMac::OnTransportReadComplete(int result) {
if (result > 0) {
recv_buffer_.insert(recv_buffer_.end(),
read_io_buf_->data(),
read_io_buf_->data() + result);
}
read_io_buf_ = NULL;
if (next_handshake_state_ != STATE_NONE) {
int rv = DoHandshakeLoop(result);
if (rv != ERR_IO_PENDING) {
LoadLog::EndEvent(load_log_, LoadLog::TYPE_SSL_CONNECT);
load_log_ = NULL;
DoConnectCallback(rv);
}
return;
}
if (user_read_buf_) {
if (result < 0) {
DoReadCallback(result);
return;
}
int rv = DoPayloadRead();
if (rv != ERR_IO_PENDING)
DoReadCallback(rv);
}
}
void SSLClientSocketMac::OnTransportWriteComplete(int result) {
write_io_buf_ = NULL;
if (result < 0) {
pending_send_error_ = result;
return;
}
send_buffer_.erase(send_buffer_.begin(),
send_buffer_.begin() + result);
if (!send_buffer_.empty())
SSLWriteCallback(this, NULL, NULL);
// Since SSLWriteCallback() lies to return noErr even if transport_->Write()
// returns ERR_IO_PENDING, we don't need to call any callbacks here.
}
// This is the main loop driving the state machine. Most calls coming from the
// outside just set up a few variables and jump into here.
int SSLClientSocketMac::DoHandshakeLoop(int last_io_result) {
DCHECK(next_handshake_state_ != STATE_NONE);
int rv = last_io_result;
do {
State state = next_handshake_state_;
next_handshake_state_ = STATE_NONE;
switch (state) {
case STATE_HANDSHAKE_START:
// Do the SSL/TLS handshake, up to the server certificate message.
rv = DoHandshakeStart();
break;
case STATE_VERIFY_CERT:
// Kick off server certificate validation.
rv = DoVerifyCert();
break;
case STATE_VERIFY_CERT_COMPLETE:
// Check the results of the server certificate validation.
rv = DoVerifyCertComplete(rv);
break;
case STATE_HANDSHAKE_FINISH:
// Do the SSL/TLS handshake, after the server certificate message.
rv = DoHandshakeFinish();
break;
default:
rv = ERR_UNEXPECTED;
NOTREACHED() << "unexpected state";
break;
}
} while (rv != ERR_IO_PENDING && next_handshake_state_ != STATE_NONE);
return rv;
}
int SSLClientSocketMac::DoHandshakeStart() {
OSStatus status = SSLHandshake(ssl_context_);
if (status == errSSLWouldBlock)
next_handshake_state_ = STATE_HANDSHAKE_START;
if (status == noErr || status == errSSLServerAuthCompletedFlag) {
// TODO(hawk): we verify the certificate chain even on resumed sessions
// so that we have the certificate status (valid, expired but overridden
// by the user, EV, etc.) available. Eliminate this step once we have
// a certificate validation result cache.
next_handshake_state_ = STATE_VERIFY_CERT;
if (status == errSSLServerAuthCompletedFlag) {
// Override errSSLServerAuthCompletedFlag as it's not actually an error,
// but rather an indication that we're only half way through the
// handshake.
handshake_interrupted_ = true;
status = noErr;
}
}
if (status == errSSLClosedGraceful) {
// The server unexpectedly closed on us.
return ERR_SSL_PROTOCOL_ERROR;
}
int net_error = NetErrorFromOSStatus(status);
if (status == noErr || IsCertificateError(net_error)) {
server_cert_ = GetServerCert(ssl_context_);
if (!server_cert_)
return ERR_UNEXPECTED;
}
return net_error;
}
int SSLClientSocketMac::DoVerifyCert() {
next_handshake_state_ = STATE_VERIFY_CERT_COMPLETE;
if (!server_cert_)
return ERR_UNEXPECTED;
int flags = 0;
if (ssl_config_.rev_checking_enabled)
flags |= X509Certificate::VERIFY_REV_CHECKING_ENABLED;
if (ssl_config_.verify_ev_cert)
flags |= X509Certificate::VERIFY_EV_CERT;
verifier_.reset(new CertVerifier);
return verifier_->Verify(server_cert_, hostname_, flags,
&server_cert_verify_result_,
&handshake_io_callback_);
}
int SSLClientSocketMac::DoVerifyCertComplete(int result) {
DCHECK(verifier_.get());
verifier_.reset();
if (IsCertificateError(result) && ssl_config_.IsAllowedBadCert(server_cert_))
result = OK;
if (handshake_interrupted_) {
// With session resumption enabled the full handshake (i.e., the handshake
// in a non-resumed session) occurs in two steps. Continue on to the second
// step if the certificate is OK.
if (result == OK)
next_handshake_state_ = STATE_HANDSHAKE_FINISH;
} else {
// If the session was resumed or session resumption was disabled, we're
// done with the handshake.
completed_handshake_ = true;
DCHECK(next_handshake_state_ == STATE_NONE);
}
return result;
}
int SSLClientSocketMac::DoHandshakeFinish() {
OSStatus status = SSLHandshake(ssl_context_);
if (status == errSSLWouldBlock)
next_handshake_state_ = STATE_HANDSHAKE_FINISH;
if (status == errSSLClosedGraceful)
return ERR_SSL_PROTOCOL_ERROR;
if (status == noErr) {
completed_handshake_ = true;
DCHECK(next_handshake_state_ == STATE_NONE);
}
return NetErrorFromOSStatus(status);
}
int SSLClientSocketMac::DoPayloadRead() {
size_t processed = 0;
OSStatus status = SSLRead(ssl_context_,
user_read_buf_->data(),
user_read_buf_len_,
&processed);
// There's a subtle difference here in semantics of the "would block" errors.
// In our code, ERR_IO_PENDING means the whole operation is async, while
// errSSLWouldBlock means that the stream isn't ending (and is often returned
// along with partial data). So even though "would block" is returned, if we
// have data, let's just return it.
if (processed > 0)
return processed;
if (status == errSSLClosedNoNotify) {
// TODO(wtc): Unless we have received the close_notify alert, we need to
// return an error code indicating that the SSL connection ended
// uncleanly, a potential truncation attack. See http://crbug.com/18586.
return OK;
}
return NetErrorFromOSStatus(status);
}
int SSLClientSocketMac::DoPayloadWrite() {
size_t processed = 0;
OSStatus status = SSLWrite(ssl_context_,
user_write_buf_->data(),
user_write_buf_len_,
&processed);
if (processed > 0)
return processed;
return NetErrorFromOSStatus(status);
}
// static
OSStatus SSLClientSocketMac::SSLReadCallback(SSLConnectionRef connection,
void* data,
size_t* data_length) {
DCHECK(data);
DCHECK(data_length);
SSLClientSocketMac* us =
const_cast<SSLClientSocketMac*>(
static_cast<const SSLClientSocketMac*>(connection));
if (us->read_io_buf_) {
// We have I/O in flight; promise we'll get back to them and use the
// existing callback to do so.
*data_length = 0;
return errSSLWouldBlock;
}
size_t total_read = us->recv_buffer_.size();
int rv = 1; // any old value to spin the loop below
while (rv > 0 && total_read < *data_length) {
us->read_io_buf_ = new IOBuffer(*data_length - total_read);
rv = us->transport_->Read(us->read_io_buf_,
*data_length - total_read,
&us->transport_read_callback_);
if (rv >= 0) {
us->recv_buffer_.insert(us->recv_buffer_.end(),
us->read_io_buf_->data(),
us->read_io_buf_->data() + rv);
us->read_io_buf_ = NULL;
total_read += rv;
}
}
*data_length = total_read;
if (total_read) {
memcpy(data, &us->recv_buffer_[0], total_read);
us->recv_buffer_.clear();
}
if (rv != ERR_IO_PENDING)
us->read_io_buf_ = NULL;
if (rv < 0)
return OSStatusFromNetError(rv);
else if (rv == 0) // stream closed
return errSSLClosedGraceful;
else
return noErr;
}
// static
OSStatus SSLClientSocketMac::SSLWriteCallback(SSLConnectionRef connection,
const void* data,
size_t* data_length) {
SSLClientSocketMac* us =
const_cast<SSLClientSocketMac*>(
static_cast<const SSLClientSocketMac*>(connection));
if (us->pending_send_error_ != OK) {
OSStatus status = OSStatusFromNetError(us->pending_send_error_);
us->pending_send_error_ = OK;
return status;
}
if (data)
us->send_buffer_.insert(us->send_buffer_.end(),
static_cast<const char*>(data),
static_cast<const char*>(data) + *data_length);
if (us->write_io_buf_) {
// If we have I/O in flight, just add the data to the end of the buffer and
// return to our caller. The existing callback will trigger the write of the
// new data when it sees that data remains in the buffer after removing the
// sent data. As always, lie to our caller.
return noErr;
}
int rv;
do {
us->write_io_buf_ = new IOBuffer(us->send_buffer_.size());
memcpy(us->write_io_buf_->data(), &us->send_buffer_[0],
us->send_buffer_.size());
rv = us->transport_->Write(us->write_io_buf_,
us->send_buffer_.size(),
&us->transport_write_callback_);
if (rv > 0) {
us->send_buffer_.erase(us->send_buffer_.begin(),
us->send_buffer_.begin() + rv);
us->write_io_buf_ = NULL;
}
} while (rv > 0 && !us->send_buffer_.empty());
if (rv < 0 && rv != ERR_IO_PENDING) {
us->write_io_buf_ = NULL;
return OSStatusFromNetError(rv);
}
// always lie to our caller
return noErr;
}
} // namespace net