Working With HTTP Headers

The plugin checks all client request headers for the Proxy-Authorization MIME field, which should contain the user name and password. The plugin’s continuation handler, auth-plugin, calls handle_dns to check the Proxy-Authorization field. The handle_dns routine uses TSHttpTxnClientReqGet and TSMimeHdrFieldFind to obtain the Proxy-Authorization field:

  1. {
  2.     TSMBuffer bufp;
  3.     TSMLoc hdr_loc;
  4.     TSMLoc field_loc;
  5.     const char *val;
  6.     char *user, *password;
  8.     if (!TSHttpTxnClientReqGet (txnp, &bufp, &hdr_loc)) {
  9.         TSError ("[basic_authorization] Couldn't retrieve client request header");
  10.         goto done;
  11.     }
  13.     field_loc = TSMimeHdrFieldFind (bufp, hdr_loc,
  14.             TS_MIME_FIELD_PROXY_AUTHORIZATION);

If the Proxy-Authorization field is present, then the plugin checks that the authentication type is “Basic”, and the user name and password are present and valid:

  1. val = TSMimeHdrFieldValueStringGet (bufp, hdr_loc, field_loc, -1, &authval_length);
  2. if (!val) {
  3.     TSError ("[basic_authorization] No value in Proxy-Authorization field");
  4.     TSHandleMLocRelease (bufp, hdr_loc, field_loc);
  5.     TSHandleMLocRelease (bufp, TS_NULL_MLOC, hdr_loc);
  6.     goto done;
  7. }
  9. if (strncmp (val, "Basic", 5) != 0) {
  10.     TSError ("[basic_authorization] No Basic auth type in Proxy-Authorization");
  11.     TSHandleMLocRelease (bufp, hdr_loc, field_loc);
  12.     TSHandleMLocRelease (bufp, TS_NULL_MLOC, hdr_loc);
  13.     goto done;
  14. }
  16. val += 5;
  17. while ((*val == ' ') || (*val == '\t')) {
  18.     val += 1;
  19. }
  21. user = base64_decode (val);
  22. password = strchr (user, ':');
  23. if (!password) {
  24.     TSError ("[basic_authorization] No password in authorization information");
  25.     TSfree (user);
  26.     TSHandleMLocRelease (bufp, hdr_loc, field_loc);
  27.     TSHandleMLocRelease (bufp, TS_NULL_MLOC, hdr_loc);
  28.     goto done;
  29. }
  30. *password = '\0';
  31. password += 1;
  33. if (!authorized (user, password)) {
  34.     TSError ("[basic_authorization] %s:%s not authorized", user, password);
  35.     TSfree (user);
  36.     TSHandleMLocRelease (bufp, hdr_loc, field_loc);
  37.     TSHandleMLocRelease (bufp, TS_NULL_MLOC, hdr_loc);
  38.     goto done;
  39. }
  41. TSfree (user);
  42. TSHandleMLocRelease (bufp, hdr_loc, field_loc);
  43. TSHandleMLocRelease (bufp, TS_NULL_MLOC, hdr_loc);
  44. TSHttpTxnReenable (txnp, TS_EVENT_HTTP_CONTINUE);
  45. return;