Revert of purge nss files and dependencies

webrtc/base/nssstreamadapter.cc

+/*
+ *  Copyright 2004 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.
+ */
+
+#include <vector>
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif  // HAVE_CONFIG_H
+
+#if HAVE_NSS_SSL_H
+
+#include "webrtc/base/nssstreamadapter.h"
+
+#include "keyhi.h"
+#include "nspr.h"
+#include "nss.h"
+#include "pk11pub.h"
+#include "secerr.h"
+
+#ifdef NSS_SSL_RELATIVE_PATH
+#include "ssl.h"
+#include "sslerr.h"
+#include "sslproto.h"
+#else
+#include "net/third_party/nss/ssl/ssl.h"
+#include "net/third_party/nss/ssl/sslerr.h"
+#include "net/third_party/nss/ssl/sslproto.h"
+#endif
+
+#include "webrtc/base/nssidentity.h"
+#include "webrtc/base/safe_conversions.h"
+#include "webrtc/base/thread.h"
+
+namespace rtc {
+
+PRDescIdentity NSSStreamAdapter::nspr_layer_identity = PR_INVALID_IO_LAYER;
+
+#define UNIMPLEMENTED \
+  PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0); \
+  LOG(LS_ERROR) \
+  << "Call to unimplemented function "<< __FUNCTION__; ASSERT(false)
+
+#ifdef SRTP_AES128_CM_HMAC_SHA1_80
+#define HAVE_DTLS_SRTP
+#endif
+
+#ifdef HAVE_DTLS_SRTP
+// SRTP cipher suite table
+struct SrtpCipherMapEntry {
+  const char* external_name;
+  PRUint16 cipher_id;
+};
+
+// This isn't elegant, but it's better than an external reference
+static const SrtpCipherMapEntry kSrtpCipherMap[] = {
+  {"AES_CM_128_HMAC_SHA1_80", SRTP_AES128_CM_HMAC_SHA1_80 },
+  {"AES_CM_128_HMAC_SHA1_32", SRTP_AES128_CM_HMAC_SHA1_32 },
+  {NULL, 0}
+};
+#endif
+
+// Ciphers to enable to get ECDHE encryption with endpoints that support it.
+static const uint32_t kEnabledCiphers[] = {
+    TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+    TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+    TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+    TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256};
+
+// Default cipher used between NSS stream adapters.
+// This needs to be updated when the default of the SSL library changes.
+static const char kDefaultSslCipher10[] =
+    "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA";
+static const char kDefaultSslCipher12[] =
+    "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256";
+static const char kDefaultSslEcCipher10[] =
+    "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA";
+static const char kDefaultSslEcCipher12[] =
+    "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256";
+
+// Implementation of NSPR methods
+static PRStatus StreamClose(PRFileDesc *socket) {
+  ASSERT(!socket->lower);
+  socket->dtor(socket);
+  return PR_SUCCESS;
+}
+
+static PRInt32 StreamRead(PRFileDesc *socket, void *buf, PRInt32 length) {
+  StreamInterface *stream = reinterpret_cast<StreamInterface *>(socket->secret);
+  size_t read;
+  int error;
+  StreamResult result = stream->Read(buf, length, &read, &error);
+  if (result == SR_SUCCESS) {
+    return checked_cast<PRInt32>(read);
+  }
+
+  if (result == SR_EOS) {
+    return 0;
+  }
+
+  if (result == SR_BLOCK) {
+    PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
+    return -1;
+  }
+
+  PR_SetError(PR_UNKNOWN_ERROR, error);
+  return -1;
+}
+
+static PRInt32 StreamWrite(PRFileDesc *socket, const void *buf,
+                           PRInt32 length) {
+  StreamInterface *stream = reinterpret_cast<StreamInterface *>(socket->secret);
+  size_t written;
+  int error;
+  StreamResult result = stream->Write(buf, length, &written, &error);
+  if (result == SR_SUCCESS) {
+    return checked_cast<PRInt32>(written);
+  }
+
+  if (result == SR_BLOCK) {
+    LOG(LS_INFO) <<
+        "NSSStreamAdapter: write to underlying transport would block";
+    PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
+    return -1;
+  }
+
+  LOG(LS_ERROR) << "Write error";
+  PR_SetError(PR_UNKNOWN_ERROR, error);
+  return -1;
+}
+
+static PRInt32 StreamAvailable(PRFileDesc *socket) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+PRInt64 StreamAvailable64(PRFileDesc *socket) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRStatus StreamSync(PRFileDesc *socket) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PROffset32 StreamSeek(PRFileDesc *socket, PROffset32 offset,
+                             PRSeekWhence how) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PROffset64 StreamSeek64(PRFileDesc *socket, PROffset64 offset,
+                               PRSeekWhence how) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRStatus StreamFileInfo(PRFileDesc *socket, PRFileInfo *info) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRStatus StreamFileInfo64(PRFileDesc *socket, PRFileInfo64 *info) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRInt32 StreamWritev(PRFileDesc *socket, const PRIOVec *iov,
+                     PRInt32 iov_size, PRIntervalTime timeout) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRStatus StreamConnect(PRFileDesc *socket, const PRNetAddr *addr,
+                              PRIntervalTime timeout) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRFileDesc *StreamAccept(PRFileDesc *sd, PRNetAddr *addr,
+                                PRIntervalTime timeout) {
+  UNIMPLEMENTED;
+  return NULL;
+}
+
+static PRStatus StreamBind(PRFileDesc *socket, const PRNetAddr *addr) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRStatus StreamListen(PRFileDesc *socket, PRIntn depth) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRStatus StreamShutdown(PRFileDesc *socket, PRIntn how) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+// Note: this is always nonblocking and ignores the timeout.
+// TODO(ekr@rtfm.com): In future verify that the socket is
+// actually in non-blocking mode.
+// This function does not support peek.
+static PRInt32 StreamRecv(PRFileDesc *socket, void *buf, PRInt32 amount,
+                   PRIntn flags, PRIntervalTime to) {
+  ASSERT(flags == 0);
+
+  if (flags != 0) {
+    PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
+    return -1;
+  }
+
+  return StreamRead(socket, buf, amount);
+}
+
+// Note: this is always nonblocking and assumes a zero timeout.
+// This function does not support peek.
+static PRInt32 StreamSend(PRFileDesc *socket, const void *buf,
+                          PRInt32 amount, PRIntn flags,
+                          PRIntervalTime to) {
+  ASSERT(flags == 0);
+
+  return StreamWrite(socket, buf, amount);
+}
+
+static PRInt32 StreamRecvfrom(PRFileDesc *socket, void *buf,
+                              PRInt32 amount, PRIntn flags,
+                              PRNetAddr *addr, PRIntervalTime to) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRInt32 StreamSendto(PRFileDesc *socket, const void *buf,
+                            PRInt32 amount, PRIntn flags,
+                            const PRNetAddr *addr, PRIntervalTime to) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRInt16 StreamPoll(PRFileDesc *socket, PRInt16 in_flags,
+                          PRInt16 *out_flags) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRInt32 StreamAcceptRead(PRFileDesc *sd, PRFileDesc **nd,
+                                PRNetAddr **raddr,
+                                void *buf, PRInt32 amount, PRIntervalTime t) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRInt32 StreamTransmitFile(PRFileDesc *sd, PRFileDesc *socket,
+                                  const void *headers, PRInt32 hlen,
+                                  PRTransmitFileFlags flags, PRIntervalTime t) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRStatus StreamGetPeerName(PRFileDesc *socket, PRNetAddr *addr) {
+  // TODO(ekr@rtfm.com): Modify to return unique names for each channel
+  // somehow, as opposed to always the same static address. The current
+  // implementation messes up the session cache, which is why it's off
+  // elsewhere
+  addr->inet.family = PR_AF_INET;
+  addr->inet.port = 0;
+  addr->inet.ip = 0;
+
+  return PR_SUCCESS;
+}
+
+static PRStatus StreamGetSockName(PRFileDesc *socket, PRNetAddr *addr) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRStatus StreamGetSockOption(PRFileDesc *socket, PRSocketOptionData *opt) {
+  switch (opt->option) {
+    case PR_SockOpt_Nonblocking:
+      opt->value.non_blocking = PR_TRUE;
+      return PR_SUCCESS;
+    default:
+      UNIMPLEMENTED;
+      break;
+  }
+
+  return PR_FAILURE;
+}
+
+// Imitate setting socket options. These are mostly noops.
+static PRStatus StreamSetSockOption(PRFileDesc *socket,
+                                    const PRSocketOptionData *opt) {
+  switch (opt->option) {
+    case PR_SockOpt_Nonblocking:
+      return PR_SUCCESS;
+    case PR_SockOpt_NoDelay:
+      return PR_SUCCESS;
+    default:
+      UNIMPLEMENTED;
+      break;
+  }
+
+  return PR_FAILURE;
+}
+
+static PRInt32 StreamSendfile(PRFileDesc *out, PRSendFileData *in,
+                              PRTransmitFileFlags flags, PRIntervalTime to) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static PRStatus StreamConnectContinue(PRFileDesc *socket, PRInt16 flags) {
+  UNIMPLEMENTED;
+  return PR_FAILURE;
+}
+
+static PRIntn StreamReserved(PRFileDesc *socket) {
+  UNIMPLEMENTED;
+  return -1;
+}
+
+static const struct PRIOMethods nss_methods = {
+  PR_DESC_LAYERED,
+  StreamClose,
+  StreamRead,
+  StreamWrite,
+  StreamAvailable,
+  StreamAvailable64,
+  StreamSync,
+  StreamSeek,
+  StreamSeek64,
+  StreamFileInfo,
+  StreamFileInfo64,
+  StreamWritev,
+  StreamConnect,
+  StreamAccept,
+  StreamBind,
+  StreamListen,
+  StreamShutdown,
+  StreamRecv,
+  StreamSend,
+  StreamRecvfrom,
+  StreamSendto,
+  StreamPoll,
+  StreamAcceptRead,
+  StreamTransmitFile,
+  StreamGetSockName,
+  StreamGetPeerName,
+  StreamReserved,
+  StreamReserved,
+  StreamGetSockOption,
+  StreamSetSockOption,
+  StreamSendfile,
+  StreamConnectContinue,
+  StreamReserved,
+  StreamReserved,
+  StreamReserved,
+  StreamReserved
+};
+
+NSSStreamAdapter::NSSStreamAdapter(StreamInterface *stream)
+    : SSLStreamAdapterHelper(stream),
+      ssl_fd_(NULL),
+      cert_ok_(false) {
+}
+
+bool NSSStreamAdapter::Init() {
+  if (nspr_layer_identity == PR_INVALID_IO_LAYER) {
+    nspr_layer_identity = PR_GetUniqueIdentity("nssstreamadapter");
+  }
+  PRFileDesc *pr_fd = PR_CreateIOLayerStub(nspr_layer_identity, &nss_methods);
+  if (!pr_fd)
+    return false;
+  pr_fd->secret = reinterpret_cast<PRFilePrivate *>(stream());
+
+  PRFileDesc *ssl_fd;
+  if (ssl_mode_ == SSL_MODE_DTLS) {
+    ssl_fd = DTLS_ImportFD(NULL, pr_fd);
+  } else {
+    ssl_fd = SSL_ImportFD(NULL, pr_fd);
+  }
+  ASSERT(ssl_fd != NULL);  // This should never happen
+  if (!ssl_fd) {
+    PR_Close(pr_fd);
+    return false;
+  }
+
+  SECStatus rv;
+  // Turn on security.
+  rv = SSL_OptionSet(ssl_fd, SSL_SECURITY, PR_TRUE);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error enabling security on SSL Socket";
+    return false;
+  }
+
+  // Disable SSLv2.
+  rv = SSL_OptionSet(ssl_fd, SSL_ENABLE_SSL2, PR_FALSE);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error disabling SSL2";
+    return false;
+  }
+
+  // Disable caching.
+  // TODO(ekr@rtfm.com): restore this when I have the caching
+  // identity set.
+  rv = SSL_OptionSet(ssl_fd, SSL_NO_CACHE, PR_TRUE);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error disabling cache";
+    return false;
+  }
+
+  // Disable session tickets.
+  rv = SSL_OptionSet(ssl_fd, SSL_ENABLE_SESSION_TICKETS, PR_FALSE);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error enabling tickets";
+    return false;
+  }
+
+  // Disable renegotiation.
+  rv = SSL_OptionSet(ssl_fd, SSL_ENABLE_RENEGOTIATION,
+                     SSL_RENEGOTIATE_NEVER);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error disabling renegotiation";
+    return false;
+  }
+
+  // Disable false start.
+  rv = SSL_OptionSet(ssl_fd, SSL_ENABLE_FALSE_START, PR_FALSE);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error disabling false start";
+    return false;
+  }
+
+  // Disable reusing of ECDHE keys. By default NSS, when in server mode, uses
+  // the same key for multiple connections, so disable this behaviour to get
+  // ephemeral keys.
+  rv = SSL_OptionSet(ssl_fd, SSL_REUSE_SERVER_ECDHE_KEY, PR_FALSE);
+  if (rv != SECSuccess) {
+    LOG(LS_ERROR) << "Error disabling ECDHE key reuse";
+    return false;
+  }
+
+  ssl_fd_ = ssl_fd;
+
+  return true;
+}
+
+NSSStreamAdapter::~NSSStreamAdapter() {
+  if (ssl_fd_)
+    PR_Close(ssl_fd_);
+};
+
+
+int NSSStreamAdapter::BeginSSL() {
+  SECStatus rv;
+
+  if (!Init()) {
+    Error("Init", -1, false);
+    return -1;
+  }
+
+  ASSERT(state_ == SSL_CONNECTING);
+  // The underlying stream has been opened. If we are in peer-to-peer mode
+  // then a peer certificate must have been specified by now.
+  ASSERT(!ssl_server_name_.empty() ||
+         peer_certificate_.get() != NULL ||
+         !peer_certificate_digest_algorithm_.empty());
+  LOG(LS_INFO) << "BeginSSL: "
+               << (!ssl_server_name_.empty() ? ssl_server_name_ :
+                                               "with peer");
+
+  if (role_ == SSL_CLIENT) {
+    LOG(LS_INFO) << "BeginSSL: as client";
+
+    rv = SSL_GetClientAuthDataHook(ssl_fd_, GetClientAuthDataHook,
+                                   this);
+    if (rv != SECSuccess) {
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+  } else {
+    LOG(LS_INFO) << "BeginSSL: as server";
+    NSSIdentity *identity;
+
+    if (identity_.get()) {
+      identity = static_cast<NSSIdentity *>(identity_.get());
+    } else {
+      LOG(LS_ERROR) << "Can't be an SSL server without an identity";
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+    rv = SSL_ConfigSecureServer(ssl_fd_, identity->certificate().certificate(),
+                                identity->keypair()->privkey(),
+                                identity->keypair()->ssl_kea_type());
+    if (rv != SECSuccess) {
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+
+    // Insist on a certificate from the client
+    rv = SSL_OptionSet(ssl_fd_, SSL_REQUEST_CERTIFICATE, PR_TRUE);
+    if (rv != SECSuccess) {
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+
+    // TODO(juberti): Check for client_auth_enabled()
+
+    rv = SSL_OptionSet(ssl_fd_, SSL_REQUIRE_CERTIFICATE, PR_TRUE);
+    if (rv != SECSuccess) {
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+  }
+
+  // Set the version range.
+  SSLVersionRange vrange;
+  if (ssl_mode_ == SSL_MODE_DTLS) {
+    vrange.min = SSL_LIBRARY_VERSION_TLS_1_1;
+    switch (ssl_max_version_) {
+      case SSL_PROTOCOL_DTLS_10:
+        vrange.max = SSL_LIBRARY_VERSION_TLS_1_1;
+        break;
+      case SSL_PROTOCOL_DTLS_12:
+      default:
+        vrange.max = SSL_LIBRARY_VERSION_TLS_1_2;
+        break;
+    }
+  } else {
+    // SSL_MODE_TLS
+    vrange.min = SSL_LIBRARY_VERSION_TLS_1_0;
+    switch (ssl_max_version_) {
+      case SSL_PROTOCOL_TLS_10:
+        vrange.max = SSL_LIBRARY_VERSION_TLS_1_0;
+        break;
+      case SSL_PROTOCOL_TLS_11:
+        vrange.max = SSL_LIBRARY_VERSION_TLS_1_1;
+        break;
+      case SSL_PROTOCOL_TLS_12:
+      default:
+        vrange.max = SSL_LIBRARY_VERSION_TLS_1_2;
+        break;
+    }
+  }
+
+  rv = SSL_VersionRangeSet(ssl_fd_, &vrange);
+  if (rv != SECSuccess) {
+    Error("BeginSSL", -1, false);
+    return -1;
+  }
+
+  // SRTP
+#ifdef HAVE_DTLS_SRTP
+  if (!srtp_ciphers_.empty()) {
+    rv = SSL_SetSRTPCiphers(
+        ssl_fd_, &srtp_ciphers_[0],
+        checked_cast<unsigned int>(srtp_ciphers_.size()));
+    if (rv != SECSuccess) {
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+  }
+#endif
+
+  // Enable additional ciphers.
+  for (size_t i = 0; i < ARRAY_SIZE(kEnabledCiphers); i++) {
+    rv = SSL_CipherPrefSet(ssl_fd_, kEnabledCiphers[i], PR_TRUE);
+    if (rv != SECSuccess) {
+      Error("BeginSSL", -1, false);
+      return -1;
+    }
+  }
+
+  // Certificate validation
+  rv = SSL_AuthCertificateHook(ssl_fd_, AuthCertificateHook, this);
+  if (rv != SECSuccess) {
+    Error("BeginSSL", -1, false);
+    return -1;
+  }
+
+  // Now start the handshake
+  rv = SSL_ResetHandshake(ssl_fd_, role_ == SSL_SERVER ? PR_TRUE : PR_FALSE);
+  if (rv != SECSuccess) {
+    Error("BeginSSL", -1, false);
+    return -1;
+  }
+
+  return ContinueSSL();
+}
+
+int NSSStreamAdapter::ContinueSSL() {
+  LOG(LS_INFO) << "ContinueSSL";
+  ASSERT(state_ == SSL_CONNECTING);
+
+  // Clear the DTLS timer
+  Thread::Current()->Clear(this, MSG_DTLS_TIMEOUT);
+
+  SECStatus rv = SSL_ForceHandshake(ssl_fd_);
+
+  if (rv == SECSuccess) {
+    LOG(LS_INFO) << "Handshake complete";
+
+    ASSERT(cert_ok_);
+    if (!cert_ok_) {
+      Error("ContinueSSL", -1, true);
+      return -1;
+    }
+
+    state_ = SSL_CONNECTED;
+    StreamAdapterInterface::OnEvent(stream(), SE_OPEN|SE_READ|SE_WRITE, 0);
+    return 0;
+  }
+
+  PRInt32 err = PR_GetError();
+  switch (err) {
+    case SSL_ERROR_RX_MALFORMED_HANDSHAKE:
+      if (ssl_mode_ != SSL_MODE_DTLS) {
+        Error("ContinueSSL", -1, true);
+        return -1;
+      } else {
+        LOG(LS_INFO) << "Malformed DTLS message. Ignoring.";
+        FALLTHROUGH();  // Fall through
+      }
+    case PR_WOULD_BLOCK_ERROR:
+      LOG(LS_INFO) << "Would have blocked";
+      if (ssl_mode_ == SSL_MODE_DTLS) {
+        PRIntervalTime timeout;
+
+        SECStatus rv = DTLS_GetHandshakeTimeout(ssl_fd_, &timeout);
+        if (rv == SECSuccess) {
+          LOG(LS_INFO) << "Timeout is " << timeout << " ms";
+          Thread::Current()->PostDelayed(PR_IntervalToMilliseconds(timeout),
+                                         this, MSG_DTLS_TIMEOUT, 0);
+        }
+      }
+
+      return 0;
+    default:
+      LOG(LS_INFO) << "Error " << err;
+      break;
+  }
+
+  Error("ContinueSSL", -1, true);
+  return -1;
+}
+
+void NSSStreamAdapter::Cleanup() {
+  if (state_ != SSL_ERROR) {
+    state_ = SSL_CLOSED;
+  }
+
+  if (ssl_fd_) {
+    PR_Close(ssl_fd_);
+    ssl_fd_ = NULL;
+  }
+
+  identity_.reset();
+  peer_certificate_.reset();
+
+  Thread::Current()->Clear(this, MSG_DTLS_TIMEOUT);
+}
+
+bool NSSStreamAdapter::GetDigestLength(const std::string& algorithm,
+                                       size_t* length) {
+  return NSSCertificate::GetDigestLength(algorithm, length);
+}
+
+StreamResult NSSStreamAdapter::Read(void* data, size_t data_len,
+                                    size_t* read, int* error) {
+  // SSL_CONNECTED sanity check.
+  switch (state_) {
+    case SSL_NONE:
+    case SSL_WAIT:
+    case SSL_CONNECTING:
+      return SR_BLOCK;
+
+    case SSL_CONNECTED:
+      break;
+
+    case SSL_CLOSED:
+      return SR_EOS;
+
+    case SSL_ERROR:
+    default:
+      if (error)
+        *error = ssl_error_code_;
+      return SR_ERROR;
+  }
+
+  PRInt32 rv = PR_Read(ssl_fd_, data, checked_cast<PRInt32>(data_len));
+
+  if (rv == 0) {
+    return SR_EOS;
+  }
+
+  // Error
+  if (rv < 0) {
+    PRInt32 err = PR_GetError();
+
+    switch (err) {
+      case PR_WOULD_BLOCK_ERROR:
+        return SR_BLOCK;
+      default:
+        Error("Read", -1, false);
+        *error = err;  // libjingle semantics are that this is impl-specific
+        return SR_ERROR;
+    }
+  }
+
+  // Success
+  *read = rv;
+
+  return SR_SUCCESS;
+}
+
+StreamResult NSSStreamAdapter::Write(const void* data, size_t data_len,
+                                     size_t* written, int* error) {
+  // SSL_CONNECTED sanity check.
+  switch (state_) {
+    case SSL_NONE:
+    case SSL_WAIT:
+    case SSL_CONNECTING:
+      return SR_BLOCK;
+
+    case SSL_CONNECTED:
+      break;
+
+    case SSL_ERROR:
+    case SSL_CLOSED:
+    default:
+      if (error)
+        *error = ssl_error_code_;
+      return SR_ERROR;
+  }
+
+  PRInt32 rv = PR_Write(ssl_fd_, data, checked_cast<PRInt32>(data_len));
+
+  // Error
+  if (rv < 0) {
+    PRInt32 err = PR_GetError();
+
+    switch (err) {
+      case PR_WOULD_BLOCK_ERROR:
+        return SR_BLOCK;
+      default:
+        Error("Write", -1, false);
+        *error = err;  // libjingle semantics are that this is impl-specific
+        return SR_ERROR;
+    }
+  }
+
+  // Success
+  *written = rv;
+
+  return SR_SUCCESS;
+}
+
+void NSSStreamAdapter::OnEvent(StreamInterface* stream, int events,
+                               int err) {
+  int events_to_signal = 0;
+  int signal_error = 0;
+  ASSERT(stream == this->stream());
+  if ((events & SE_OPEN)) {
+    LOG(LS_INFO) << "NSSStreamAdapter::OnEvent SE_OPEN";
+    if (state_ != SSL_WAIT) {
+      ASSERT(state_ == SSL_NONE);
+      events_to_signal |= SE_OPEN;
+    } else {
+      state_ = SSL_CONNECTING;
+      if (int err = BeginSSL()) {
+        Error("BeginSSL", err, true);
+        return;
+      }
+    }
+  }
+  if ((events & (SE_READ|SE_WRITE))) {
+    LOG(LS_INFO) << "NSSStreamAdapter::OnEvent"
+                 << ((events & SE_READ) ? " SE_READ" : "")
+                 << ((events & SE_WRITE) ? " SE_WRITE" : "");
+    if (state_ == SSL_NONE) {
+      events_to_signal |= events & (SE_READ|SE_WRITE);
+    } else if (state_ == SSL_CONNECTING) {
+      if (int err = ContinueSSL()) {
+        Error("ContinueSSL", err, true);
+        return;
+      }
+    } else if (state_ == SSL_CONNECTED) {
+      if (events & SE_WRITE) {
+        LOG(LS_INFO) << " -- onStreamWriteable";
+        events_to_signal |= SE_WRITE;
+      }
+      if (events & SE_READ) {
+        LOG(LS_INFO) << " -- onStreamReadable";
+        events_to_signal |= SE_READ;
+      }
+    }
+  }
+  if ((events & SE_CLOSE)) {
+    LOG(LS_INFO) << "NSSStreamAdapter::OnEvent(SE_CLOSE, " << err << ")";
+    Cleanup();
+    events_to_signal |= SE_CLOSE;
+    // SE_CLOSE is the only event that uses the final parameter to OnEvent().
+    ASSERT(signal_error == 0);
+    signal_error = err;
+  }
+  if (events_to_signal)
+    StreamAdapterInterface::OnEvent(stream, events_to_signal, signal_error);
+}
+
+void NSSStreamAdapter::OnMessage(Message* msg) {
+  // Process our own messages and then pass others to the superclass
+  if (MSG_DTLS_TIMEOUT == msg->message_id) {
+    LOG(LS_INFO) << "DTLS timeout expired";
+    ContinueSSL();
+  } else {
+    StreamInterface::OnMessage(msg);
+  }
+}
+
+// Certificate verification callback. Called to check any certificate
+SECStatus NSSStreamAdapter::AuthCertificateHook(void *arg,
+                                                PRFileDesc *fd,
+                                                PRBool checksig,
+                                                PRBool isServer) {
+  LOG(LS_INFO) << "NSSStreamAdapter::AuthCertificateHook";
+  // SSL_PeerCertificate returns a pointer that is owned by the caller, and
+  // the NSSCertificate constructor copies its argument, so |raw_peer_cert|
+  // must be destroyed in this function.
+  CERTCertificate* raw_peer_cert = SSL_PeerCertificate(fd);
+  NSSCertificate peer_cert(raw_peer_cert);
+  CERT_DestroyCertificate(raw_peer_cert);
+
+  NSSStreamAdapter *stream = reinterpret_cast<NSSStreamAdapter *>(arg);
+  stream->cert_ok_ = false;
+
+  // Read the peer's certificate chain.
+  CERTCertList* cert_list = SSL_PeerCertificateChain(fd);
+  ASSERT(cert_list != NULL);
+
+  // If the peer provided multiple certificates, check that they form a valid
+  // chain as defined by RFC 5246 Section 7.4.2: "Each following certificate
+  // MUST directly certify the one preceding it.".  This check does NOT
+  // verify other requirements, such as whether the chain reaches a trusted
+  // root, self-signed certificates have valid signatures, certificates are not
+  // expired, etc.
+  // Even if the chain is valid, the leaf certificate must still match a
+  // provided certificate or digest.
+  if (!NSSCertificate::IsValidChain(cert_list)) {
+    CERT_DestroyCertList(cert_list);
+    PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
+    return SECFailure;
+  }
+
+  if (stream->peer_certificate_.get()) {
+    LOG(LS_INFO) << "Checking against specified certificate";
+
+    // The peer certificate was specified
+    if (reinterpret_cast<NSSCertificate *>(stream->peer_certificate_.get())->
+        Equals(&peer_cert)) {
+      LOG(LS_INFO) << "Accepted peer certificate";
+      stream->cert_ok_ = true;
+    }
+  } else if (!stream->peer_certificate_digest_algorithm_.empty()) {
+    LOG(LS_INFO) << "Checking against specified digest";
+    // The peer certificate digest was specified
+    unsigned char digest[64];  // Maximum size
+    size_t digest_length;
+
+    if (!peer_cert.ComputeDigest(
+            stream->peer_certificate_digest_algorithm_,
+            digest, sizeof(digest), &digest_length)) {
+      LOG(LS_ERROR) << "Digest computation failed";
+    } else {
+      Buffer computed_digest(digest, digest_length);
+      if (computed_digest == stream->peer_certificate_digest_value_) {
+        LOG(LS_INFO) << "Accepted peer certificate";
+        stream->cert_ok_ = true;
+      }
+    }
+  } else {
+    // Other modes, but we haven't implemented yet
+    // TODO(ekr@rtfm.com): Implement real certificate validation
+    UNIMPLEMENTED;
+  }
+
+  if (!stream->cert_ok_ && stream->ignore_bad_cert()) {
+    LOG(LS_WARNING) << "Ignoring cert error while verifying cert chain";
+    stream->cert_ok_ = true;
+  }
+
+  if (stream->cert_ok_)
+    stream->peer_certificate_.reset(new NSSCertificate(cert_list));
+
+  CERT_DestroyCertList(cert_list);
+
+  if (stream->cert_ok_)
+    return SECSuccess;
+
+  PORT_SetError(SEC_ERROR_UNTRUSTED_CERT);
+  return SECFailure;
+}
+
+
+SECStatus NSSStreamAdapter::GetClientAuthDataHook(void *arg, PRFileDesc *fd,
+                                                  CERTDistNames *caNames,
+                                                  CERTCertificate **pRetCert,
+                                                  SECKEYPrivateKey **pRetKey) {
+  LOG(LS_INFO) << "Client cert requested";
+  NSSStreamAdapter *stream = reinterpret_cast<NSSStreamAdapter *>(arg);
+
+  if (!stream->identity_.get()) {
+    LOG(LS_ERROR) << "No identity available";
+    return SECFailure;
+  }
+
+  NSSIdentity *identity = static_cast<NSSIdentity *>(stream->identity_.get());
+  // Destroyed internally by NSS
+  *pRetCert = CERT_DupCertificate(identity->certificate().certificate());
+  *pRetKey = SECKEY_CopyPrivateKey(identity->keypair()->privkey());
+
+  return SECSuccess;
+}
+
+bool NSSStreamAdapter::GetSslCipher(std::string* cipher) {
+  ASSERT(state_ == SSL_CONNECTED);
+  if (state_ != SSL_CONNECTED)
+    return false;
+
+  SSLChannelInfo channel_info;
+  SECStatus rv = SSL_GetChannelInfo(ssl_fd_, &channel_info,
+                                    sizeof(channel_info));
+  if (rv == SECFailure)
+    return false;
+
+  SSLCipherSuiteInfo ciphersuite_info;
+  rv = SSL_GetCipherSuiteInfo(channel_info.cipherSuite, &ciphersuite_info,
+                              sizeof(ciphersuite_info));
+  if (rv == SECFailure)
+    return false;
+
+  *cipher = ciphersuite_info.cipherSuiteName;
+  return true;
+}
+
+// RFC 5705 Key Exporter
+bool NSSStreamAdapter::ExportKeyingMaterial(const std::string& label,
+                                            const uint8* context,
+                                            size_t context_len,
+                                            bool use_context,
+                                            uint8* result,
+                                            size_t result_len) {
+  SECStatus rv = SSL_ExportKeyingMaterial(
+      ssl_fd_,
+      label.c_str(),
+      checked_cast<unsigned int>(label.size()),
+      use_context,
+      context,
+      checked_cast<unsigned int>(context_len),
+      result,
+      checked_cast<unsigned int>(result_len));
+
+  return rv == SECSuccess;
+}
+
+bool NSSStreamAdapter::SetDtlsSrtpCiphers(
+    const std::vector<std::string>& ciphers) {
+#ifdef HAVE_DTLS_SRTP
+  std::vector<PRUint16> internal_ciphers;
+  if (state_ != SSL_NONE)
+    return false;
+
+  for (std::vector<std::string>::const_iterator cipher = ciphers.begin();
+       cipher != ciphers.end(); ++cipher) {
+    bool found = false;
+    for (const SrtpCipherMapEntry *entry = kSrtpCipherMap; entry->cipher_id;
+         ++entry) {
+      if (*cipher == entry->external_name) {
+        found = true;
+        internal_ciphers.push_back(entry->cipher_id);
+        break;
+      }
+    }
+
+    if (!found) {
+      LOG(LS_ERROR) << "Could not find cipher: " << *cipher;
+      return false;
+    }
+  }
+
+  if (internal_ciphers.empty())
+    return false;
+
+  srtp_ciphers_ = internal_ciphers;
+
+  return true;
+#else
+  return false;
+#endif
+}
+
+bool NSSStreamAdapter::GetDtlsSrtpCipher(std::string* cipher) {
+#ifdef HAVE_DTLS_SRTP
+  ASSERT(state_ == SSL_CONNECTED);
+  if (state_ != SSL_CONNECTED)
+    return false;
+
+  PRUint16 selected_cipher;
+
+  SECStatus rv = SSL_GetSRTPCipher(ssl_fd_, &selected_cipher);
+  if (rv == SECFailure)
+    return false;
+
+  for (const SrtpCipherMapEntry *entry = kSrtpCipherMap;
+       entry->cipher_id; ++entry) {
+    if (selected_cipher == entry->cipher_id) {
+      *cipher = entry->external_name;
+      return true;
+    }
+  }
+
+  ASSERT(false);  // This should never happen
+#endif
+  return false;
+}
+
+
+GlobalLockPod NSSContext::lock;
+NSSContext *NSSContext::global_nss_context;
+
+// Static initialization and shutdown
+NSSContext *NSSContext::Instance() {
+  lock.Lock();
+  if (!global_nss_context) {
+    scoped_ptr<NSSContext> new_ctx(new NSSContext(PK11_GetInternalSlot()));
+    if (new_ctx->slot_)
+      global_nss_context = new_ctx.release();
+  }
+  lock.Unlock();
+
+  return global_nss_context;
+}
+
+bool NSSContext::InitializeSSL(VerificationCallback callback) {
+  ASSERT(!callback);
+
+  static bool initialized = false;
+
+  if (!initialized) {
+    SECStatus rv;
+
+    rv = NSS_NoDB_Init(NULL);
+    if (rv != SECSuccess) {
+      LOG(LS_ERROR) << "Couldn't initialize NSS error=" <<
+          PORT_GetError();
+      return false;
+    }
+
+    NSS_SetDomesticPolicy();
+
+    initialized = true;
+  }
+
+  return true;
+}
+
+bool NSSContext::InitializeSSLThread() {
+  // Not needed
+  return true;
+}
+
+bool NSSContext::CleanupSSL() {
+  // Not needed
+  return true;
+}
+
+bool NSSStreamAdapter::HaveDtls() {
+  return true;
+}
+
+bool NSSStreamAdapter::HaveDtlsSrtp() {
+#ifdef HAVE_DTLS_SRTP
+  return true;
+#else
+  return false;
+#endif
+}
+
+bool NSSStreamAdapter::HaveExporter() {
+  return true;
+}
+
+std::string NSSStreamAdapter::GetDefaultSslCipher(SSLProtocolVersion version,
+                                                  KeyType key_type) {
+  if (key_type == KT_RSA) {
+    switch (version) {
+      case SSL_PROTOCOL_TLS_10:
+      case SSL_PROTOCOL_TLS_11:
+        return kDefaultSslCipher10;
+      case SSL_PROTOCOL_TLS_12:
+      default:
+        return kDefaultSslCipher12;
+    }
+  } else if (key_type == KT_ECDSA) {
+    switch (version) {
+      case SSL_PROTOCOL_TLS_10:
+      case SSL_PROTOCOL_TLS_11:
+        return kDefaultSslEcCipher10;
+      case SSL_PROTOCOL_TLS_12:
+      default:
+        return kDefaultSslEcCipher12;
+    }
+  } else {
+    return std::string();
+  }
+}
+
+}  // namespace rtc
+
+#endif  // HAVE_NSS_SSL_H