/* ldap-misc.c - Miscellaneous helpers for LDAP functions
 * Copyright (C) 2015, 2021 g10 Code GmbH
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses/>.
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

#include <config.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "dirmngr-err.h"
#include "../common/util.h"
#include "ldap-misc.h"


/* Convert an LDAP error to a GPG error.  */
gpg_err_code_t
ldap_err_to_gpg_err (int code)
{
  gpg_err_code_t ec;

  switch (code)
    {
#ifdef LDAP_X_CONNECTING
    case LDAP_X_CONNECTING: ec = GPG_ERR_LDAP_X_CONNECTING; break;
#endif

    case LDAP_REFERRAL_LIMIT_EXCEEDED: ec = GPG_ERR_LDAP_REFERRAL_LIMIT; break;
    case LDAP_CLIENT_LOOP: ec = GPG_ERR_LDAP_CLIENT_LOOP; break;
    case LDAP_NO_RESULTS_RETURNED: ec = GPG_ERR_LDAP_NO_RESULTS; break;
    case LDAP_CONTROL_NOT_FOUND: ec = GPG_ERR_LDAP_CONTROL_NOT_FOUND; break;
    case LDAP_NOT_SUPPORTED: ec = GPG_ERR_LDAP_NOT_SUPPORTED; break;
    case LDAP_CONNECT_ERROR: ec = GPG_ERR_LDAP_CONNECT; break;
    case LDAP_NO_MEMORY: ec = GPG_ERR_LDAP_NO_MEMORY; break;
    case LDAP_PARAM_ERROR: ec = GPG_ERR_LDAP_PARAM; break;
    case LDAP_USER_CANCELLED: ec = GPG_ERR_LDAP_USER_CANCELLED; break;
    case LDAP_FILTER_ERROR: ec = GPG_ERR_LDAP_FILTER; break;
    case LDAP_AUTH_UNKNOWN: ec = GPG_ERR_LDAP_AUTH_UNKNOWN; break;
    case LDAP_TIMEOUT: ec = GPG_ERR_LDAP_TIMEOUT; break;
    case LDAP_DECODING_ERROR: ec = GPG_ERR_LDAP_DECODING; break;
    case LDAP_ENCODING_ERROR: ec = GPG_ERR_LDAP_ENCODING; break;
    case LDAP_LOCAL_ERROR: ec = GPG_ERR_LDAP_LOCAL; break;
    case LDAP_SERVER_DOWN: ec = GPG_ERR_LDAP_SERVER_DOWN; break;

    case LDAP_SUCCESS: ec = GPG_ERR_LDAP_SUCCESS; break;

    case LDAP_OPERATIONS_ERROR: ec = GPG_ERR_LDAP_OPERATIONS; break;
    case LDAP_PROTOCOL_ERROR: ec = GPG_ERR_LDAP_PROTOCOL; break;
    case LDAP_TIMELIMIT_EXCEEDED: ec = GPG_ERR_LDAP_TIMELIMIT; break;
    case LDAP_SIZELIMIT_EXCEEDED: ec = GPG_ERR_LDAP_SIZELIMIT; break;
    case LDAP_COMPARE_FALSE: ec = GPG_ERR_LDAP_COMPARE_FALSE; break;
    case LDAP_COMPARE_TRUE: ec = GPG_ERR_LDAP_COMPARE_TRUE; break;
    case LDAP_AUTH_METHOD_NOT_SUPPORTED: ec=GPG_ERR_LDAP_UNSUPPORTED_AUTH;break;
    case LDAP_STRONG_AUTH_REQUIRED: ec = GPG_ERR_LDAP_STRONG_AUTH_RQRD; break;
    case LDAP_PARTIAL_RESULTS: ec = GPG_ERR_LDAP_PARTIAL_RESULTS; break;
    case LDAP_REFERRAL: ec = GPG_ERR_LDAP_REFERRAL; break;

#ifdef LDAP_ADMINLIMIT_EXCEEDED
    case LDAP_ADMINLIMIT_EXCEEDED: ec = GPG_ERR_LDAP_ADMINLIMIT; break;
#endif

#ifdef LDAP_UNAVAILABLE_CRITICAL_EXTENSION
    case LDAP_UNAVAILABLE_CRITICAL_EXTENSION:
                               ec = GPG_ERR_LDAP_UNAVAIL_CRIT_EXTN; break;
#endif

    case LDAP_CONFIDENTIALITY_REQUIRED: ec = GPG_ERR_LDAP_CONFIDENT_RQRD; break;
    case LDAP_SASL_BIND_IN_PROGRESS: ec = GPG_ERR_LDAP_SASL_BIND_INPROG; break;
    case LDAP_NO_SUCH_ATTRIBUTE: ec = GPG_ERR_LDAP_NO_SUCH_ATTRIBUTE; break;
    case LDAP_UNDEFINED_TYPE: ec = GPG_ERR_LDAP_UNDEFINED_TYPE; break;
    case LDAP_INAPPROPRIATE_MATCHING: ec = GPG_ERR_LDAP_BAD_MATCHING; break;
    case LDAP_CONSTRAINT_VIOLATION: ec = GPG_ERR_LDAP_CONST_VIOLATION; break;

#ifdef LDAP_TYPE_OR_VALUE_EXISTS
    case LDAP_TYPE_OR_VALUE_EXISTS: ec = GPG_ERR_LDAP_TYPE_VALUE_EXISTS; break;
#endif

    case LDAP_INVALID_SYNTAX: ec = GPG_ERR_LDAP_INV_SYNTAX; break;
    case LDAP_NO_SUCH_OBJECT: ec = GPG_ERR_LDAP_NO_SUCH_OBJ; break;
    case LDAP_ALIAS_PROBLEM: ec = GPG_ERR_LDAP_ALIAS_PROBLEM; break;
    case LDAP_INVALID_DN_SYNTAX: ec = GPG_ERR_LDAP_INV_DN_SYNTAX; break;
    case LDAP_IS_LEAF: ec = GPG_ERR_LDAP_IS_LEAF; break;
    case LDAP_ALIAS_DEREF_PROBLEM: ec = GPG_ERR_LDAP_ALIAS_DEREF; break;

#ifdef LDAP_X_PROXY_AUTHZ_FAILURE
    case LDAP_X_PROXY_AUTHZ_FAILURE: ec = GPG_ERR_LDAP_X_PROXY_AUTH_FAIL; break;
#endif

    case LDAP_INAPPROPRIATE_AUTH: ec = GPG_ERR_LDAP_BAD_AUTH; break;
    case LDAP_INVALID_CREDENTIALS: ec = GPG_ERR_LDAP_INV_CREDENTIALS; break;

#ifdef LDAP_INSUFFICIENT_ACCESS
    case LDAP_INSUFFICIENT_ACCESS: ec = GPG_ERR_LDAP_INSUFFICIENT_ACC; break;
#endif

    case LDAP_BUSY: ec = GPG_ERR_LDAP_BUSY; break;
    case LDAP_UNAVAILABLE: ec = GPG_ERR_LDAP_UNAVAILABLE; break;
    case LDAP_UNWILLING_TO_PERFORM: ec = GPG_ERR_LDAP_UNWILL_TO_PERFORM; break;
    case LDAP_LOOP_DETECT: ec = GPG_ERR_LDAP_LOOP_DETECT; break;
    case LDAP_NAMING_VIOLATION: ec = GPG_ERR_LDAP_NAMING_VIOLATION; break;
    case LDAP_OBJECT_CLASS_VIOLATION: ec = GPG_ERR_LDAP_OBJ_CLS_VIOLATION; break;
    case LDAP_NOT_ALLOWED_ON_NONLEAF: ec=GPG_ERR_LDAP_NOT_ALLOW_NONLEAF;break;
    case LDAP_NOT_ALLOWED_ON_RDN: ec = GPG_ERR_LDAP_NOT_ALLOW_ON_RDN; break;
    case LDAP_ALREADY_EXISTS: ec = GPG_ERR_LDAP_ALREADY_EXISTS; break;
    case LDAP_NO_OBJECT_CLASS_MODS: ec = GPG_ERR_LDAP_NO_OBJ_CLASS_MODS; break;
    case LDAP_RESULTS_TOO_LARGE: ec = GPG_ERR_LDAP_RESULTS_TOO_LARGE; break;
    case LDAP_AFFECTS_MULTIPLE_DSAS: ec = GPG_ERR_LDAP_AFFECTS_MULT_DSAS; break;

#ifdef LDAP_VLV_ERROR
    case LDAP_VLV_ERROR: ec = GPG_ERR_LDAP_VLV; break;
#endif

    case LDAP_OTHER: ec = GPG_ERR_LDAP_OTHER; break;

#ifdef LDAP_CUP_RESOURCES_EXHAUSTED
    case LDAP_CUP_RESOURCES_EXHAUSTED: ec=GPG_ERR_LDAP_CUP_RESOURCE_LIMIT;break;
    case LDAP_CUP_SECURITY_VIOLATION: ec=GPG_ERR_LDAP_CUP_SEC_VIOLATION; break;
    case LDAP_CUP_INVALID_DATA: ec = GPG_ERR_LDAP_CUP_INV_DATA; break;
    case LDAP_CUP_UNSUPPORTED_SCHEME: ec = GPG_ERR_LDAP_CUP_UNSUP_SCHEME; break;
    case LDAP_CUP_RELOAD_REQUIRED: ec = GPG_ERR_LDAP_CUP_RELOAD; break;
#endif

#ifdef LDAP_CANCELLED
    case LDAP_CANCELLED: ec = GPG_ERR_LDAP_CANCELLED; break;
#endif

#ifdef LDAP_NO_SUCH_OPERATION
    case LDAP_NO_SUCH_OPERATION: ec = GPG_ERR_LDAP_NO_SUCH_OPERATION; break;
#endif

#ifdef LDAP_TOO_LATE
    case LDAP_TOO_LATE: ec = GPG_ERR_LDAP_TOO_LATE; break;
#endif

#ifdef LDAP_CANNOT_CANCEL
    case LDAP_CANNOT_CANCEL: ec = GPG_ERR_LDAP_CANNOT_CANCEL; break;
#endif

#ifdef LDAP_ASSERTION_FAILED
    case LDAP_ASSERTION_FAILED: ec = GPG_ERR_LDAP_ASSERTION_FAILED; break;
#endif

#ifdef LDAP_PROXIED_AUTHORIZATION_DENIED
    case LDAP_PROXIED_AUTHORIZATION_DENIED:
                                      ec = GPG_ERR_LDAP_PROX_AUTH_DENIED; break;
#endif

    default:
#if defined(LDAP_E_ERROR) && defined(LDAP_X_ERROR)
      if (LDAP_E_ERROR (code))
        ec = GPG_ERR_LDAP_E_GENERAL;
      else if (LDAP_X_ERROR (code))
        ec = GPG_ERR_LDAP_X_GENERAL;
      else
#endif
        ec = GPG_ERR_LDAP_GENERAL;
      break;
    }

  return ec;
}


/* Retrieve an LDAP error and return it's GPG equivalent.  */
gpg_err_code_t
ldap_to_gpg_err (LDAP *ld)
{
#if defined(HAVE_LDAP_GET_OPTION) && defined(LDAP_OPT_ERROR_NUMBER)
  int err;

  if (ldap_get_option (ld, LDAP_OPT_ERROR_NUMBER, &err) == 0)
    return ldap_err_to_gpg_err (err);
  else
    return GPG_ERR_GENERAL;
#elif defined(HAVE_LDAP_LD_ERRNO)
  return ldap_err_to_gpg_err (ld->ld_errno);
#else
  /* We should never get here since the LDAP library should always
     have either ldap_get_option or ld_errno, but just in case... */
  return GPG_ERR_INTERNAL;
#endif
}



/* Parse an extended filter syntax as used by dirmngr_ldap.c
 * For example:
 *
 *   ^CN=foo, OU=My Users&(objectClasses=*)
 *
 * Uses "CN=foo, OU=My Users" as base DN and "(objectClasses=*)" as
 * filter.  If the base prefix includes an ampersand, it needs to be
 * doubled.  The usual escaping rules for DNs (for the base) and
 * filters apply.  Other examples:
 *
 *  ^CN=foo, OU=My Users&
 *
 * Use just the base DN.
 *
 *  ^CN=foo, OU=My Users&SCOPE&
 *
 * Specify the scope which is "base", "one", or "sub".  May of course
 * also be followed by a filter.
 *
 *  ^&SCOPE&(objectClasses=*)
 *
 * Give a scope and a filter.  Note that R_SCOPE is only changed if a
 * STRING has scope parameter.  Setting this initally to -1 allows to
 * detect this case.
 */
gpg_error_t
ldap_parse_extfilter (const char *string, int silent,
                      char **r_base, int *r_scope, char **r_filter)
{
  gpg_error_t err = 0;
  char *base = NULL;
  char *filter = NULL;
  const char *s;
  char *p;

  if (r_base)
    *r_base = NULL;
  if (r_filter)
    *r_filter = NULL;

  if (*string == '^')
    {
      string++;
      base = xtrymalloc (strlen (string)+1);
      if (!base)
        {
          err = gpg_error_from_syserror ();
          goto leave;
        }
      for (s=string, p=base; *s; s++)
        {
          *p++ = *s;
          if (*s == '&' && s[1] == '&')
            s++;  /* Skip quoted ampersand.  */
          else if (*s == '&')
            {
              p--;
              break;
            }
        }
      *p = 0;
      if (!*s)
        {
          if (!silent)
            log_info ("LDAP extended filter is not terminated\n");
          err = gpg_error (GPG_ERR_SYNTAX);
          goto leave;
        }
      string = s + 1;
    }

  if (!*string)
    goto leave; /* ready.  */

  if (!strncmp (string, "base&", 5))
    {
      string += 5;
      if (r_scope)
        *r_scope = LDAP_SCOPE_BASE;
    }
  else if (!strncmp (string, "one&", 4))
    {
      string += 4;
      if (r_scope)
        *r_scope = LDAP_SCOPE_ONELEVEL;
    }
  else if (!strncmp (string, "sub&", 4))
    {
      string += 4;
      if (r_scope)
        *r_scope = LDAP_SCOPE_SUBTREE;
    }

  if (!*string)
    goto leave; /* ready.  */

  if (*string != '(')
    {
      if (!silent)
        log_info ("LDAP filter does not start with a left parentheses\n");
      return gpg_error (GPG_ERR_SYNTAX);
    }
  if (string[strlen(string)-1] != ')')
    {
      if (!silent)
        log_info ("LDAP filter does not end with a right parentheses\n");
      return gpg_error (GPG_ERR_SYNTAX);
    }

  filter = xtrystrdup (string);
  if (!filter)
    err = gpg_error_from_syserror ();

 leave:
  if (err)
    {
      xfree (base);
      xfree (filter);
    }
  else
    {
      if (r_base)
        *r_base = base;
      else
        xfree (base);
      if (r_filter)
        *r_filter = filter;
      else
        xfree (filter);
    }
  return err;
}



/* Scan an ISO timestamp and return a Generalized Time according to
 * RFC-4517.  The only supported format is "yyyymmddThhmmss[Z]"
 * delimited by white space, nul, a colon or a comma.  Returns a
 * malloced string or NULL for an invalid string or on memory
 * error.  */
char *
isotime2rfc4517 (const char *string)
{
  int year, month, day, hour, minu, sec;

  if (!isotime_p (string))
    {
      errno = 0;
      return NULL;
    }

  year  = atoi_4 (string);
  month = atoi_2 (string + 4);
  day   = atoi_2 (string + 6);
  hour  = atoi_2 (string + 9);
  minu  = atoi_2 (string + 11);
  sec   = atoi_2 (string + 13);

  /* Basic checks (1600 due to the LDAP time format base)  */
  if (year < 1600 || month < 1 || month > 12 || day < 1 || day > 31
      || hour > 23 || minu > 59 || sec > 61 )
    {
      errno = 0;
      return NULL;
    }

  return gpgrt_bsprintf ("%04d%02d%02d%02d%02d%02d.0Z",
                         year, month, day, hour, minu, sec);
}


/* Parse an LDAP Generalized Time string and update the provided
 * isotime buffer.  On error return and error code.  */
gpg_error_t
rfc4517toisotime (gnupg_isotime_t timebuf, const char *string)
{
  int i;
  int year, month, day, hour, minu, sec;
  const char *s;

  /* Sample value: "20230823141623Z";  */
  for (i=0, s=string; i < 10; i++, s++)  /* Need yyyymmddhh  */
    if (!digitp (s))
      return gpg_error (GPG_ERR_INV_TIME);
  year  = atoi_4 (string);
  month = atoi_2 (string + 4);
  day   = atoi_2 (string + 6);
  hour  = atoi_2 (string + 8);
  minu = 0;
  sec = 0;
  if (digitp (s) && digitp (s+1))
    {
      minu = atoi_2 (s);
      s += 2;
      if (digitp (s) && digitp (s+1))
        {
          sec = atoi_2 (s);
          s += 2;
        }
    }
  if (*s == '.' || *s == ',')
    {
      s++;
      if (!digitp (s))  /* At least one digit of the fraction required.  */
        return gpg_error (GPG_ERR_INV_TIME);
      s++;
      while (digitp (s))
        s++;
    }
  if (*s == 'Z' && (!s[1] || spacep (s+1)))
    ; /* stop here.  */
  else if (*s == '-' || *s == '+')
    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);  /* FIXME */
  else
    return gpg_error (GPG_ERR_INV_TIME);

  snprintf (timebuf, sizeof (gnupg_isotime_t), "%04d%02d%02dT%02d%02d%02d",
            year, month, day, hour, minu, sec);
  return 0;
}