curl_darwinssl.c

   * SSLSetConnection() will not copy that address. I've found that
   * conn->sock[sockindex] may change on its own. */
  connssl->ssl_sockfd = sockfd;
  err = SSLSetConnection(connssl->ssl_ctx, connssl);
  if(err != noErr) {
    failf(data, "SSL: SSLSetConnection() failed: %d", err);
    return CURLE_SSL_CONNECT_ERROR;
  }

  connssl->connecting_state = ssl_connect_2;
  return CURLE_OK;
}

static CURLcode
darwinssl_connect_step2(struct connectdata *conn, int sockindex)
{
  struct SessionHandle *data = conn->data;
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  OSStatus err;
  SSLCipherSuite cipher;
  SSLProtocol protocol = 0;

  DEBUGASSERT(ssl_connect_2 == connssl->connecting_state
              || ssl_connect_2_reading == connssl->connecting_state
              || ssl_connect_2_writing == connssl->connecting_state);

  /* Here goes nothing: */
  err = SSLHandshake(connssl->ssl_ctx);

  if(err != noErr) {
    switch (err) {
      case errSSLWouldBlock:  /* they're not done with us yet */
        connssl->connecting_state = connssl->ssl_direction ?
            ssl_connect_2_writing : ssl_connect_2_reading;
        return CURLE_OK;

      /* The below is errSSLServerAuthCompleted; it's not defined in
        Leopard's headers */
      case -9841:
        /* the documentation says we need to call SSLHandshake() again */
        return darwinssl_connect_step2(conn, sockindex);

      /* These are all certificate problems with the server: */
      case errSSLXCertChainInvalid:
        failf(data, "SSL certificate problem: Invalid certificate chain");
        return CURLE_SSL_CACERT;
      case errSSLUnknownRootCert:
        failf(data, "SSL certificate problem: Untrusted root certificate");
        return CURLE_SSL_CACERT;
      case errSSLNoRootCert:
        failf(data, "SSL certificate problem: No root certificate");
        return CURLE_SSL_CACERT;
      case errSSLCertExpired:
        failf(data, "SSL certificate problem: Certificate chain had an "
              "expired certificate");
        return CURLE_SSL_CACERT;
      case errSSLBadCert:
        failf(data, "SSL certificate problem: Couldn't understand the server "
              "certificate format");
        return CURLE_SSL_CONNECT_ERROR;

      /* This error is raised if the server's cert didn't match the server's
         host name: */
      case errSSLHostNameMismatch:
        failf(data, "SSL certificate peer verification failed, the "
              "certificate did not match \"%s\"\n", conn->host.dispname);
        return CURLE_PEER_FAILED_VERIFICATION;

      /* Generic handshake errors: */
      case errSSLConnectionRefused:
        failf(data, "Server dropped the connection during the SSL handshake");
        return CURLE_SSL_CONNECT_ERROR;
      case errSSLClosedAbort:
        failf(data, "Server aborted the SSL handshake");
        return CURLE_SSL_CONNECT_ERROR;
      case errSSLNegotiation:
        failf(data, "Could not negotiate an SSL cipher suite with the server");
        return CURLE_SSL_CONNECT_ERROR;
      /* Sometimes paramErr happens with buggy ciphers: */
      case paramErr: case errSSLInternal:
        failf(data, "Internal SSL engine error encountered during the "
              "SSL handshake");
        return CURLE_SSL_CONNECT_ERROR;
      case errSSLFatalAlert:
        failf(data, "Fatal SSL engine error encountered during the SSL "
              "handshake");
        return CURLE_SSL_CONNECT_ERROR;
      default:
        failf(data, "Unknown SSL protocol error in connection to %s:%d",
              conn->host.name, err);
        return CURLE_SSL_CONNECT_ERROR;
    }
  }
  else {
    /* we have been connected fine, we're not waiting for anything else. */
    connssl->connecting_state = ssl_connect_3;

    /* Informational message */
    (void)SSLGetNegotiatedCipher(connssl->ssl_ctx, &cipher);
    (void)SSLGetNegotiatedProtocolVersion(connssl->ssl_ctx, &protocol);
    switch (protocol) {
      case kSSLProtocol2:
        infof(data, "SSL 2.0 connection using %s\n",
              SSLCipherNameForNumber(cipher));
        break;
      case kSSLProtocol3:
        infof(data, "SSL 3.0 connection using %s\n",
              SSLCipherNameForNumber(cipher));
        break;
      case kTLSProtocol1:
        infof(data, "TLS 1.0 connection using %s\n",
              TLSCipherNameForNumber(cipher));
        break;
#if defined(__MAC_10_8) || defined(__IPHONE_5_0)
      case kTLSProtocol11:
        infof(data, "TLS 1.1 connection using %s\n",
              TLSCipherNameForNumber(cipher));
        break;
      case kTLSProtocol12:
        infof(data, "TLS 1.2 connection using %s\n",
              TLSCipherNameForNumber(cipher));
        break;
#endif
      default:
        infof(data, "Unknown protocol connection\n");
        break;
    }

    return CURLE_OK;
  }
}

static CURLcode
darwinssl_connect_step3(struct connectdata *conn,
                        int sockindex)
{
  struct SessionHandle *data = conn->data;
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  CFStringRef server_cert_summary;
  char server_cert_summary_c[128];
  CFArrayRef server_certs;
  SecCertificateRef server_cert;
  OSStatus err;
  CFIndex i, count;
  SecTrustRef trust;

  /* There is no step 3!
   * Well, okay, if verbose mode is on, let's print the details of the
   * server certificates. */
#if defined(__MAC_10_7) || defined(__IPHONE_5_0)
#if (TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)
#pragma unused(server_certs)
  err = SSLCopyPeerTrust(connssl->ssl_ctx, &trust);
  if(err == noErr) {
    count = SecTrustGetCertificateCount(trust);
    for(i = 0L ; i < count ; i++) {
      server_cert = SecTrustGetCertificateAtIndex(trust, i);
      server_cert_summary = CopyCertSubject(server_cert);
      memset(server_cert_summary_c, 0, 128);
      if(CFStringGetCString(server_cert_summary,
                            server_cert_summary_c,
                            128,
                            kCFStringEncodingUTF8)) {
        infof(data, "Server certificate: %s\n", server_cert_summary_c);
      }
      CFRelease(server_cert_summary);
    }
    CFRelease(trust);
  }
#else
  /* SSLCopyPeerCertificates() is deprecated as of Mountain Lion.
     The function SecTrustGetCertificateAtIndex() is officially present
     in Lion, but it is unfortunately also present in Snow Leopard as
     private API and doesn't work as expected. So we have to look for
     a different symbol to make sure this code is only executed under
     Lion or later. */
  if(SecTrustEvaluateAsync != NULL) {
#pragma unused(server_certs)
    err = SSLCopyPeerTrust(connssl->ssl_ctx, &trust);
    if(err == noErr) {
      count = SecTrustGetCertificateCount(trust);
      for(i = 0L ; i < count ; i++) {
        server_cert = SecTrustGetCertificateAtIndex(trust, i);
        server_cert_summary = CopyCertSubject(server_cert);
        memset(server_cert_summary_c, 0, 128);
        if(CFStringGetCString(server_cert_summary,
                              server_cert_summary_c,
                              128,
                              kCFStringEncodingUTF8)) {
          infof(data, "Server certificate: %s\n", server_cert_summary_c);
        }
        CFRelease(server_cert_summary);
      }
      CFRelease(trust);
    }
  }
  else {
    err = SSLCopyPeerCertificates(connssl->ssl_ctx, &server_certs);
    if(err == noErr) {
      count = CFArrayGetCount(server_certs);
      for(i = 0L ; i < count ; i++) {
        server_cert = (SecCertificateRef)CFArrayGetValueAtIndex(server_certs,
                                                                i);

        server_cert_summary = CopyCertSubject(server_cert);
        memset(server_cert_summary_c, 0, 128);
        if(CFStringGetCString(server_cert_summary,
                              server_cert_summary_c,
                              128,
                              kCFStringEncodingUTF8)) {
          infof(data, "Server certificate: %s\n", server_cert_summary_c);
        }
        CFRelease(server_cert_summary);
      }
      CFRelease(server_certs);
    }
  }
#endif /* (TARGET_OS_EMBEDDED || TARGET_OS_IPHONE) */
#else
#pragma unused(trust)
  err = SSLCopyPeerCertificates(connssl->ssl_ctx, &server_certs);
  if(err == noErr) {
    count = CFArrayGetCount(server_certs);
    for(i = 0L ; i < count ; i++) {
      server_cert = (SecCertificateRef)CFArrayGetValueAtIndex(server_certs, i);
      server_cert_summary = CopyCertSubject(server_cert);
      memset(server_cert_summary_c, 0, 128);
      if(CFStringGetCString(server_cert_summary,
                            server_cert_summary_c,
                            128,
                            kCFStringEncodingUTF8)) {
        infof(data, "Server certificate: %s\n", server_cert_summary_c);
      }
      CFRelease(server_cert_summary);
    }
    CFRelease(server_certs);
  }
#endif /* defined(__MAC_10_7) || defined(__IPHONE_5_0) */

  connssl->connecting_state = ssl_connect_done;
  return CURLE_OK;
}

static Curl_recv darwinssl_recv;
static Curl_send darwinssl_send;

static CURLcode
darwinssl_connect_common(struct connectdata *conn,
                         int sockindex,
                         bool nonblocking,
                         bool *done)
{
  CURLcode retcode;
  struct SessionHandle *data = conn->data;
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  curl_socket_t sockfd = conn->sock[sockindex];
  long timeout_ms;
  int what;

  /* check if the connection has already been established */
  if(ssl_connection_complete == connssl->state) {
    *done = TRUE;
    return CURLE_OK;
  }

  if(ssl_connect_1==connssl->connecting_state) {
    /* Find out how much more time we're allowed */
    timeout_ms = Curl_timeleft(data, NULL, TRUE);

    if(timeout_ms < 0) {
      /* no need to continue if time already is up */
      failf(data, "SSL connection timeout");
      return CURLE_OPERATION_TIMEDOUT;
    }
    retcode = darwinssl_connect_step1(conn, sockindex);
    if(retcode)
      return retcode;
  }

  while(ssl_connect_2 == connssl->connecting_state ||
        ssl_connect_2_reading == connssl->connecting_state ||
        ssl_connect_2_writing == connssl->connecting_state) {

    /* check allowed time left */
    timeout_ms = Curl_timeleft(data, NULL, TRUE);

    if(timeout_ms < 0) {
      /* no need to continue if time already is up */
      failf(data, "SSL connection timeout");
      return CURLE_OPERATION_TIMEDOUT;
    }

    /* if ssl is expecting something, check if it's available. */
    if(connssl->connecting_state == ssl_connect_2_reading
       || connssl->connecting_state == ssl_connect_2_writing) {

      curl_socket_t writefd = ssl_connect_2_writing ==
      connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
      curl_socket_t readfd = ssl_connect_2_reading ==
      connssl->connecting_state?sockfd:CURL_SOCKET_BAD;

      what = Curl_socket_ready(readfd, writefd, nonblocking?0:timeout_ms);
      if(what < 0) {
        /* fatal error */
        failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
        return CURLE_SSL_CONNECT_ERROR;
      }
      else if(0 == what) {
        if(nonblocking) {
          *done = FALSE;
          return CURLE_OK;
        }
        else {
          /* timeout */
          failf(data, "SSL connection timeout");
          return CURLE_OPERATION_TIMEDOUT;
        }
      }
      /* socket is readable or writable */
    }

    /* Run transaction, and return to the caller if it failed or if this
     * connection is done nonblocking and this loop would execute again. This
     * permits the owner of a multi handle to abort a connection attempt
     * before step2 has completed while ensuring that a client using select()
     * or epoll() will always have a valid fdset to wait on.
     */
    retcode = darwinssl_connect_step2(conn, sockindex);
    if(retcode || (nonblocking &&
                   (ssl_connect_2 == connssl->connecting_state ||
                    ssl_connect_2_reading == connssl->connecting_state ||
                    ssl_connect_2_writing == connssl->connecting_state)))
      return retcode;

  } /* repeat step2 until all transactions are done. */


  if(ssl_connect_3==connssl->connecting_state) {
    retcode = darwinssl_connect_step3(conn, sockindex);
    if(retcode)
      return retcode;
  }

  if(ssl_connect_done==connssl->connecting_state) {
    connssl->state = ssl_connection_complete;
    conn->recv[sockindex] = darwinssl_recv;
    conn->send[sockindex] = darwinssl_send;
    *done = TRUE;
  }
  else
    *done = FALSE;

  /* Reset our connect state machine */
  connssl->connecting_state = ssl_connect_1;

  return CURLE_OK;
}

CURLcode
Curl_darwinssl_connect_nonblocking(struct connectdata *conn,
                                   int sockindex,
                                   bool *done)
{
  return darwinssl_connect_common(conn, sockindex, TRUE, done);
}

CURLcode
Curl_darwinssl_connect(struct connectdata *conn,
                       int sockindex)
{
  CURLcode retcode;
  bool done = FALSE;

  retcode = darwinssl_connect_common(conn, sockindex, FALSE, &done);

  if(retcode)
    return retcode;

  DEBUGASSERT(done);

  return CURLE_OK;
}

void Curl_darwinssl_close(struct connectdata *conn, int sockindex)
{
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];

  if(connssl->ssl_ctx) {
    (void)SSLClose(connssl->ssl_ctx);
#if defined(__MAC_10_8) || defined(__IPHONE_5_0)
    if(SSLCreateContext != NULL)
      CFRelease(connssl->ssl_ctx);
#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
    else
      (void)SSLDisposeContext(connssl->ssl_ctx);
#endif  /* (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)) */
#else
    (void)SSLDisposeContext(connssl->ssl_ctx);
#endif /* defined(__MAC_10_8) || defined(__IPHONE_5_0) */
    connssl->ssl_ctx = NULL;
  }
  connssl->ssl_sockfd = 0;
}

void Curl_darwinssl_close_all(struct SessionHandle *data)
{
  /* SecureTransport doesn't separate sessions from contexts, so... */
  (void)data;
}

int Curl_darwinssl_shutdown(struct connectdata *conn, int sockindex)
{
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  struct SessionHandle *data = conn->data;
  ssize_t nread;
  int what;
  int rc;
  char buf[120];

  if(!connssl->ssl_ctx)
    return 0;

  if(data->set.ftp_ccc != CURLFTPSSL_CCC_ACTIVE)
    return 0;

  Curl_darwinssl_close(conn, sockindex);

  rc = 0;

  what = Curl_socket_ready(conn->sock[sockindex],
                           CURL_SOCKET_BAD, SSL_SHUTDOWN_TIMEOUT);

  for(;;) {
    if(what < 0) {
      /* anything that gets here is fatally bad */
      failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
      rc = -1;
      break;
    }

    if(!what) {                                /* timeout */
      failf(data, "SSL shutdown timeout");
      break;
    }

    /* Something to read, let's do it and hope that it is the close
     notify alert from the server. No way to SSL_Read now, so use read(). */

    nread = read(conn->sock[sockindex], buf, sizeof(buf));

    if(nread < 0) {
      failf(data, "read: %s", strerror(errno));
      rc = -1;
    }

    if(nread <= 0)
      break;

    what = Curl_socket_ready(conn->sock[sockindex], CURL_SOCKET_BAD, 0);
  }

  return rc;
}

size_t Curl_darwinssl_version(char *buffer, size_t size)
{
  return snprintf(buffer, size, "SecureTransport");
}

/*
 * This function uses SSLGetSessionState to determine connection status.
 *
 * Return codes:
 *     1 means the connection is still in place
 *     0 means the connection has been closed
 *    -1 means the connection status is unknown
 */
int Curl_darwinssl_check_cxn(struct connectdata *conn)
{
  struct ssl_connect_data *connssl = &conn->ssl[FIRSTSOCKET];
  OSStatus err;
  SSLSessionState state;

  if(connssl->ssl_ctx) {
    err = SSLGetSessionState(connssl->ssl_ctx, &state);
    if(err == noErr)
      return state == kSSLConnected || state == kSSLHandshake;
    return -1;
  }
  return 0;
}

bool Curl_darwinssl_data_pending(const struct connectdata *conn,
                                 int connindex)
{
  const struct ssl_connect_data *connssl = &conn->ssl[connindex];
  OSStatus err;
  size_t buffer;

  if(connssl->ssl_ctx) {  /* SSL is in use */
    err = SSLGetBufferedReadSize(connssl->ssl_ctx, &buffer);
    if(err == noErr)
      return buffer > 0UL;
    return false;
  }
  else
    return false;
}

void Curl_darwinssl_random(struct SessionHandle *data,
                           unsigned char *entropy,
                           size_t length)
{
  /* arc4random_buf() isn't available on cats older than Lion, so let's
     do this manually for the benefit of the older cats. */
  size_t i;
  u_int32_t random_number = 0;

  for(i = 0 ; i < length ; i++) {
    if(i % sizeof(u_int32_t) == 0)
      random_number = arc4random();
    entropy[i] = random_number & 0xFF;
    random_number >>= 8;
  }
  i = random_number = 0;
  (void)data;
}

void Curl_darwinssl_md5sum(unsigned char *tmp, /* input */
                           size_t tmplen,
                           unsigned char *md5sum, /* output */
                           size_t md5len)
{
  (void)md5len;
  (void)CC_MD5(tmp, (CC_LONG)tmplen, md5sum);
}

static ssize_t darwinssl_send(struct connectdata *conn,
                              int sockindex,
                              const void *mem,
                              size_t len,
                              CURLcode *curlcode)
{
  /*struct SessionHandle *data = conn->data;*/
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  size_t processed = 0UL;
  OSStatus err;

  /* The SSLWrite() function works a little differently than expected. The
     fourth argument (processed) is currently documented in Apple's
     documentation as: "On return, the length, in bytes, of the data actually
     written."

     Now, one could interpret that as "written to the socket," but actually,
     it returns the amount of data that was written to a buffer internal to
     the SSLContextRef instead. So it's possible for SSLWrite() to return
     errSSLWouldBlock and a number of bytes "written" because those bytes were
     encrypted and written to a buffer, not to the socket.

     So if this happens, then we need to keep calling SSLWrite() over and
     over again with no new data until it quits returning errSSLWouldBlock. */

  /* Do we have buffered data to write from the last time we were called? */
  if(connssl->ssl_write_buffered_length) {
    /* Write the buffered data: */
    err = SSLWrite(connssl->ssl_ctx, NULL, 0UL, &processed);
    switch (err) {
      case noErr:
        /* processed is always going to be 0 because we didn't write to
           the buffer, so return how much was written to the socket */
        processed = connssl->ssl_write_buffered_length;
        connssl->ssl_write_buffered_length = 0UL;
        break;
      case errSSLWouldBlock: /* argh, try again */
        *curlcode = CURLE_AGAIN;
        return -1L;
      default:
        failf(conn->data, "SSLWrite() returned error %d", err);
        *curlcode = CURLE_SEND_ERROR;
        return -1L;
    }
  }
  else {
    /* We've got new data to write: */
    err = SSLWrite(connssl->ssl_ctx, mem, len, &processed);
    if(err != noErr) {
      switch (err) {
        case errSSLWouldBlock:
          /* Data was buffered but not sent, we have to tell the caller
             to try sending again, and remember how much was buffered */
          connssl->ssl_write_buffered_length = len;
          *curlcode = CURLE_AGAIN;
          return -1L;
        default:
          failf(conn->data, "SSLWrite() returned error %d", err);
          *curlcode = CURLE_SEND_ERROR;
          return -1L;
      }
    }
  }
  return (ssize_t)processed;
}

static ssize_t darwinssl_recv(struct connectdata *conn,
                              int num,
                              char *buf,
                              size_t buffersize,
                              CURLcode *curlcode)
{
  /*struct SessionHandle *data = conn->data;*/
  struct ssl_connect_data *connssl = &conn->ssl[num];
  size_t processed = 0UL;
  OSStatus err = SSLRead(connssl->ssl_ctx, buf, buffersize, &processed);

  if(err != noErr) {
    switch (err) {
      case errSSLWouldBlock:  /* return how much we read (if anything) */
        if(processed)
          return (ssize_t)processed;
        *curlcode = CURLE_AGAIN;
        return -1L;
        break;

      /* errSSLClosedGraceful - server gracefully shut down the SSL session
         errSSLClosedNoNotify - server hung up on us instead of sending a
           closure alert notice, read() is returning 0
         Either way, inform the caller that the server disconnected. */
      case errSSLClosedGraceful:
      case errSSLClosedNoNotify:
        *curlcode = CURLE_OK;
        return -1L;
        break;

      default:
        failf(conn->data, "SSLRead() return error %d", err);
        *curlcode = CURLE_RECV_ERROR;
        return -1L;
        break;
    }
  }
  return (ssize_t)processed;
}

#endif /* USE_DARWINSSL */