/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"

#include "safe-memset.h"

#include "sasl-server-protected.h"

static void

mech_plain_auth_continue(struct sasl_server_mech_request *request,

       const unsigned char *data, size_t data_size)

{

  const char *authid, *authenid;

  char *pass;

  size_t i, len;

  int count;

  /* authorization ID \0 authentication ID \0 pass. */

  authid = (const char *) data;

  authenid = NULL; pass = NULL;

  count = 0;

  for (i = 0; i < data_size; i++) {

    if (data[i] == '\0') {

      if (++count == 1)

        authenid = (const char *) data + i+1;

      else if (count == 2) {

        i++;

        len = data_size - i;

        pass = p_strndup(unsafe_data_stack_pool,

             data+i, len);

      }

      else

        break;

    }

  }

  if (count == 2 && authenid != NULL && strcmp(authid, authenid) == 0) {

    /* the login username isn't different */

    authid = "";

  }

  if (count != 2) {

    /* invalid input */

    e_info(request->event, "invalid input");

    sasl_server_request_failure(request);

  } else if (!sasl_server_request_set_authid(

      request, SASL_SERVER_AUTHID_TYPE_USERNAME, authenid)) {

    /* invalid username */

    sasl_server_request_failure(request);

  } else if (*authid != '\0' &&

       !sasl_server_request_set_authzid(request, authid)) {

    /* invalid login username */

    sasl_server_request_failure(request);

  } else {

    sasl_server_request_verify_plain(

      request, pass, sasl_server_mech_plain_verify_callback);

  }

  /* make sure it's cleared */

  if (pass != NULL)

    safe_memset(pass, 0, strlen(pass));

}

static const struct sasl_server_mech_funcs mech_plain_funcs = {

  .auth_initial = sasl_server_mech_generic_auth_initial,

  .auth_continue = mech_plain_auth_continue,

};

static const struct sasl_server_mech_def mech_plain = {

  .name = SASL_MECH_NAME_PLAIN,

  .flags = SASL_MECH_SEC_PLAINTEXT | SASL_MECH_SEC_ALLOW_NULS,

  .passdb_need = SASL_MECH_PASSDB_NEED_VERIFY_PLAIN,

  .funcs = &mech_plain_funcs,

};

void sasl_server_mech_register_plain(struct sasl_server_instance *sinst)

{

  sasl_server_mech_register(sinst, &mech_plain, NULL);

}