/* 

   Unix SMB/CIFS implementation.

   Samba utility functions

   Copyright (C) Andrew Tridgell 2009

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009

   This program 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.

   This program 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 <http://www.gnu.org/licenses/>.

*/

#include "includes.h"

#include "dsdb/samdb/samdb.h"

#include <ldb_module.h>

#include "librpc/ndr/libndr.h"

#include "libcli/security/dom_sid.h"

#include "lib/util/smb_strtox.h"

enum dsdb_dn_format dsdb_dn_oid_to_format(const char *oid) 

{

  if (strcmp(oid, LDB_SYNTAX_DN) == 0) {

    return DSDB_NORMAL_DN;

  } else if (strcmp(oid, DSDB_SYNTAX_BINARY_DN) == 0) {

    return DSDB_BINARY_DN;

  } else if (strcmp(oid, DSDB_SYNTAX_STRING_DN) == 0) {

    return DSDB_STRING_DN;

  } else if (strcmp(oid, DSDB_SYNTAX_OR_NAME) == 0) {

    return DSDB_NORMAL_DN;

  } else {

    return DSDB_INVALID_DN;

  }

}

static struct dsdb_dn *dsdb_dn_construct_internal(TALLOC_CTX *mem_ctx, 

              struct ldb_dn *dn, 

              DATA_BLOB extra_part, 

              enum dsdb_dn_format dn_format, 

              const char *oid) 

{

  struct dsdb_dn *dsdb_dn = NULL;

  switch (dn_format) {

  case DSDB_BINARY_DN:

  case DSDB_STRING_DN:

    break;

  case DSDB_NORMAL_DN:

    if (extra_part.length != 0) {

      errno = EINVAL;

      return NULL;

    }

    break;

  case DSDB_INVALID_DN:

  default:

    errno = EINVAL;

    return NULL;

  }

  dsdb_dn = talloc(mem_ctx, struct dsdb_dn);

  if (!dsdb_dn) {

    errno = ENOMEM;

    return NULL;

  }

  dsdb_dn->dn = talloc_steal(dsdb_dn, dn);

  dsdb_dn->extra_part = extra_part;

  dsdb_dn->dn_format = dn_format;

  dsdb_dn->oid = oid;

  talloc_steal(dsdb_dn, extra_part.data);

  return dsdb_dn;

}

struct dsdb_dn *dsdb_dn_construct(TALLOC_CTX *mem_ctx, struct ldb_dn *dn, DATA_BLOB extra_part, 

          const char *oid) 

{

  enum dsdb_dn_format dn_format = dsdb_dn_oid_to_format(oid);

  return dsdb_dn_construct_internal(mem_ctx, dn, extra_part, dn_format, oid);

}

struct dsdb_dn *dsdb_dn_parse_trusted(TALLOC_CTX *mem_ctx, struct ldb_context *ldb, 

              const struct ldb_val *dn_blob, const char *dn_oid)

{

  struct dsdb_dn *dsdb_dn;

  struct ldb_dn *dn;

  size_t len;

  TALLOC_CTX *tmp_ctx;

  char *p1;

  char *p2;

  uint32_t blen;

  struct ldb_val bval;

  struct ldb_val dval;

  char *dn_str;

  int error = 0;

  enum dsdb_dn_format dn_format = dsdb_dn_oid_to_format(dn_oid);

  if (dn_blob == NULL || dn_blob->data == NULL || dn_blob->length == 0) {

    return NULL;

  }

  switch (dn_format) {

  case DSDB_INVALID_DN:

    return NULL;

  case DSDB_NORMAL_DN:

  {

    dn = ldb_dn_from_ldb_val(mem_ctx, ldb, dn_blob);

    if (!dn) {

      talloc_free(dn);

      return NULL;

    }

    return dsdb_dn_construct_internal(mem_ctx, dn, data_blob_null, dn_format, dn_oid);

  }

  case DSDB_BINARY_DN:

    if (dn_blob->length < 2 || dn_blob->data[0] != 'B' || dn_blob->data[1] != ':') {

      return NULL;

    }

    break;

  case DSDB_STRING_DN:

    if (dn_blob->length < 2 || dn_blob->data[0] != 'S' || dn_blob->data[1] != ':') {

      return NULL;

    }

    break;

  default:

    return NULL;

  }

  if (strlen((const char*)dn_blob->data) != dn_blob->length) {

    /* The RDN must not contain a character with value 0x0 */

    return NULL;

  }

  tmp_ctx = talloc_new(mem_ctx);

  if (tmp_ctx == NULL) {

    return NULL;

  }

  len = dn_blob->length - 2;

  p1 = talloc_strndup(tmp_ctx, (const char *)dn_blob->data + 2, len);

  if (!p1) {

    goto failed;

  }

  errno = 0;

  blen = smb_strtoul(p1, &p2, 10, &error, SMB_STR_STANDARD);

  if (error != 0) {

    DEBUG(10, (__location__ ": failed\n"));

    goto failed;

  }

  if (p2 == NULL) {

    DEBUG(10, (__location__ ": failed\n"));

    goto failed;

  }

  if (p2[0] != ':') {

    DEBUG(10, (__location__ ": failed\n"));

    goto failed;

  }

  len -= PTR_DIFF(p2,p1);//???

  p1 = p2+1;

  len--;

  if (blen >= len) {

    DEBUG(10, (__location__ ": blen=%u len=%u\n", (unsigned)blen, (unsigned)len));

    goto failed;

  }

  p2 = p1 + blen;

  if (p2[0] != ':') {

    DEBUG(10, (__location__ ": %s", p2));

    goto failed;

  }

  dn_str = p2+1;

  switch (dn_format) {

  case DSDB_BINARY_DN:

    if ((blen % 2 != 0)) {

      DEBUG(10, (__location__ ": blen=%u - not an even number\n", (unsigned)blen));

      goto failed;

    }

    if (blen >= 2) {

      bval.length = (blen/2)+1;

      bval.data = talloc_size(tmp_ctx, bval.length);

      if (bval.data == NULL) {

        DEBUG(10, (__location__ ": err\n"));

        goto failed;

      }

      bval.data[bval.length-1] = 0;

      bval.length = strhex_to_str((char *)bval.data, bval.length,

                p1, blen);

      if (bval.length != (blen / 2)) {

        DEBUG(10, (__location__ ": non hexadecimal characters found in binary prefix\n"));

        goto failed;

      }

    } else {

      bval = data_blob_null;

    }

    break;

  case DSDB_STRING_DN:

    bval = data_blob(p1, blen);

    break;

  default:

    /* never reached */

    return NULL;

  }

  dval.data = (uint8_t *)dn_str;

  dval.length = strlen(dn_str);

  dn = ldb_dn_from_ldb_val(tmp_ctx, ldb, &dval);

  if (!dn) {

    DEBUG(10, (__location__ ": err\n"));

    goto failed;

  }

  dsdb_dn = dsdb_dn_construct(mem_ctx, dn, bval, dn_oid);

  talloc_free(tmp_ctx);

  return dsdb_dn;

failed:

  talloc_free(tmp_ctx);

  return NULL;

}

struct dsdb_dn *dsdb_dn_parse(TALLOC_CTX *mem_ctx, struct ldb_context *ldb, 

            const struct ldb_val *dn_blob, const char *dn_oid)

{

  struct dsdb_dn *dsdb_dn = dsdb_dn_parse_trusted(mem_ctx, ldb,

              dn_blob, dn_oid);

  if (dsdb_dn == NULL) {

    return NULL;

  }

  if (ldb_dn_validate(dsdb_dn->dn) == false) {

    DEBUG(10, ("could not parse %.*s as a %s DN\n",

         (int)dn_blob->length, dn_blob->data,

         dn_oid));

    return NULL;

  }

  return dsdb_dn;

}

static char *dsdb_dn_get_with_postfix(TALLOC_CTX *mem_ctx, 

             struct dsdb_dn *dsdb_dn,

             const char *postfix)

{

  if (!postfix) {

    return NULL;

  }

  switch (dsdb_dn->dn_format) {

  case DSDB_NORMAL_DN:

  {

    return talloc_strdup(mem_ctx, postfix);

  }

  case DSDB_BINARY_DN:

  {

    char *hexstr = data_blob_hex_string_upper(mem_ctx, &dsdb_dn->extra_part);

    char *p = talloc_asprintf(mem_ctx, "B:%u:%s:%s", (unsigned)(dsdb_dn->extra_part.length*2), hexstr, 

            postfix);

    talloc_free(hexstr);

    return p;

  }

  case DSDB_STRING_DN:

  {

    return talloc_asprintf(mem_ctx, "S:%u:%*.*s:%s", 

            (unsigned)(dsdb_dn->extra_part.length), 

            (int)(dsdb_dn->extra_part.length), 

            (int)(dsdb_dn->extra_part.length), 

            (const char *)dsdb_dn->extra_part.data, 

            postfix);

  }

  default:

    return NULL;

  }

}

char *dsdb_dn_get_linearized(TALLOC_CTX *mem_ctx, 

            struct dsdb_dn *dsdb_dn)

{

  const char *postfix = ldb_dn_get_linearized(dsdb_dn->dn);

  return dsdb_dn_get_with_postfix(mem_ctx, dsdb_dn, postfix);

}

char *dsdb_dn_get_casefold(TALLOC_CTX *mem_ctx, 

         struct dsdb_dn *dsdb_dn) 

{

  const char *postfix = ldb_dn_get_casefold(dsdb_dn->dn);

  return dsdb_dn_get_with_postfix(mem_ctx, dsdb_dn, postfix);

}

char *dsdb_dn_get_extended_linearized(TALLOC_CTX *mem_ctx, 

              struct dsdb_dn *dsdb_dn,

              int mode)

{

  char *postfix = ldb_dn_get_extended_linearized(mem_ctx, dsdb_dn->dn, mode);

  char *ret = dsdb_dn_get_with_postfix(mem_ctx, dsdb_dn, postfix);

  talloc_free(postfix);

  return ret;

}

int dsdb_dn_binary_canonicalise(struct ldb_context *ldb, void *mem_ctx,

        const struct ldb_val *in, struct ldb_val *out)

{

  struct dsdb_dn *dsdb_dn = dsdb_dn_parse(mem_ctx, ldb, in, DSDB_SYNTAX_BINARY_DN);

  if (!dsdb_dn) {

    return -1;

  }

  *out = data_blob_string_const(dsdb_dn_get_casefold(mem_ctx, dsdb_dn));

  talloc_free(dsdb_dn);

  if (!out->data) {

    return -1;

  }

  return 0;

}

int dsdb_dn_binary_comparison(struct ldb_context *ldb, void *mem_ctx,

             const struct ldb_val *v1,

             const struct ldb_val *v2)

{

  return ldb_any_comparison(ldb, mem_ctx, dsdb_dn_binary_canonicalise, v1, v2);

}

int dsdb_dn_string_canonicalise(struct ldb_context *ldb, void *mem_ctx,

        const struct ldb_val *in, struct ldb_val *out)

{

  struct dsdb_dn *dsdb_dn = dsdb_dn_parse(mem_ctx, ldb, in, DSDB_SYNTAX_STRING_DN);

  if (!dsdb_dn) {

    return -1;

  }

  *out = data_blob_string_const(dsdb_dn_get_casefold(mem_ctx, dsdb_dn));

  talloc_free(dsdb_dn);

  if (!out->data) {

    return -1;

  }

  return 0;

}

int dsdb_dn_string_comparison(struct ldb_context *ldb, void *mem_ctx,

             const struct ldb_val *v1,

             const struct ldb_val *v2)

{

  return ldb_any_comparison(ldb, mem_ctx, dsdb_dn_string_canonicalise, v1, v2);

}

/*

 * format a drsuapi_DsReplicaObjectIdentifier naming context as a string for debugging

 *

 * When forming a DN for DB access you must use drs_ObjectIdentifier_to_dn()

 */

char *drs_ObjectIdentifier_to_debug_string(TALLOC_CTX *mem_ctx,

             struct drsuapi_DsReplicaObjectIdentifier *nc)

{

  char *ret = NULL;

  TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);

  if (!GUID_all_zero(&nc->guid)) {

    char *guid = GUID_string(tmp_ctx, &nc->guid);

    if (guid) {

      ret = talloc_asprintf_append(ret, "<GUID=%s>;", guid);

    }

  }

  if (nc->__ndr_size_sid != 0 && nc->sid.sid_rev_num != 0) {

    const char *sid = dom_sid_string(tmp_ctx, &nc->sid);

    if (sid) {

      ret = talloc_asprintf_append(ret, "<SID=%s>;", sid);

    }

  }

  if (nc->__ndr_size_dn != 0 && nc->dn) {

    ret = talloc_asprintf_append(ret, "%s", nc->dn);

  }

  talloc_free(tmp_ctx);

  talloc_steal(mem_ctx, ret);

  return ret;

}

/*

 * Safely convert a drsuapi_DsReplicaObjectIdentifier into an LDB DN

 *

 * We need to have GUID and SID priority and not allow extended

 * components in the DN.

 *

 * We must also totally honour the priority even if the string DN is not valid or able to parse as a DN.

 */

static struct ldb_dn *drs_ObjectIdentifier_to_dn(TALLOC_CTX *mem_ctx,

             struct ldb_context *ldb,

             struct drsuapi_DsReplicaObjectIdentifier *nc)

{

  struct ldb_dn *new_dn = NULL;

  if (!GUID_all_zero(&nc->guid)) {

    struct GUID_txt_buf buf;

    char *guid = GUID_buf_string(&nc->guid, &buf);

    new_dn = ldb_dn_new_fmt(mem_ctx,

          ldb,

          "<GUID=%s>",

          guid);

    if (new_dn == NULL) {

      DBG_ERR("Failed to prepare drs_ObjectIdentifier "

        "GUID %s into a DN\n",

        guid);

      return NULL;

    }

    return new_dn;

  }

  if (nc->__ndr_size_sid != 0 && nc->sid.sid_rev_num != 0) {

    struct dom_sid_buf buf;

    char *sid = dom_sid_str_buf(&nc->sid, &buf);

    new_dn = ldb_dn_new_fmt(mem_ctx,

          ldb,

          "<SID=%s>",

          sid);

    if (new_dn == NULL) {

      DBG_ERR("Failed to prepare drs_ObjectIdentifier "

        "SID %s into a DN\n",

        sid);

      return NULL;

    }

    return new_dn;

  }

  if (nc->__ndr_size_dn != 0 && nc->dn) {

    int dn_comp_num = 0;

    bool new_dn_valid = false;

    new_dn = ldb_dn_new(mem_ctx, ldb, nc->dn);

    if (new_dn == NULL) {

      /* Set to WARNING as this is user-controlled, don't print the value into the logs */

      DBG_WARNING("Failed to parse string DN in "

            "drs_ObjectIdentifier into an LDB DN\n");

      return NULL;

    }

    new_dn_valid = ldb_dn_validate(new_dn);

    if (!new_dn_valid) {

      /*

       * Set to WARNING as this is user-controlled,

       * but can print the value into the logs as it

       * parsed a bit

       */

      DBG_WARNING("Failed to validate string DN [%s] in "

            "drs_ObjectIdentifier as an LDB DN\n",

            ldb_dn_get_linearized(new_dn));

      return NULL;

    }

    dn_comp_num = ldb_dn_get_comp_num(new_dn);

    if (dn_comp_num <= 0) {

      /*

       * Set to WARNING as this is user-controlled,

       * but can print the value into the logs as it

       * parsed a bit

       */

      DBG_WARNING("DN [%s] in drs_ObjectIdentifier "

            "must have 1 or more components\n",

            ldb_dn_get_linearized(new_dn));

      return NULL;

    }

    if (ldb_dn_is_special(new_dn)) {

      /*

       * Set to WARNING as this is user-controlled,

       * but can print the value into the logs as it

       * parsed a bit

       */

      DBG_WARNING("New string DN [%s] in "

            "drs_ObjectIdentifier is a "

            "special LDB DN\n",

            ldb_dn_get_linearized(new_dn));

      return NULL;

    }

    /*

     * We want this just to be a string DN, extended

     * components are manually handled above

     */

    if (ldb_dn_has_extended(new_dn)) {

      /*

       * Set to WARNING as this is user-controlled,

       * but can print the value into the logs as it

       * parsed a bit

       */

      DBG_WARNING("Refusing to parse New string DN [%s] in "

            "drs_ObjectIdentifier as an "

            "extended LDB DN "

            "(GUIDs and SIDs should be in the "

            ".guid and .sid IDL elements, "

            "not in the string\n",

            ldb_dn_get_extended_linearized(mem_ctx,

                   new_dn,

                   1));

      return NULL;

    }

    return new_dn;

  }

  DBG_WARNING("Refusing to parse empty string DN "

        "(and no GUID or SID) "

        "drs_ObjectIdentifier into a empty "

        "(eg RootDSE) LDB DN\n");

  return NULL;

}

/*

 * Safely convert a drsuapi_DsReplicaObjectIdentifier into a validated

 * LDB DN of an existing DB entry, and/or find the NC root

 *

 * We need to have GUID and SID priority and not allow extended

 * components in the DN.

 *

 * We must also totally honour the priority even if the string DN is

 * not valid or able to parse as a DN.

 *

 * Finally, we must return the DN as found in the DB, as otherwise a

 * subsequent ldb_dn_compare(dn, nc_root) will fail (as this is based

 * on the string components).

 */

int drs_ObjectIdentifier_to_dn_and_nc_root(TALLOC_CTX *mem_ctx,

             struct ldb_context *ldb,

             struct drsuapi_DsReplicaObjectIdentifier *nc,

             struct ldb_dn **normalised_dn,

             struct ldb_dn **nc_root)

{

  int ret;

  struct ldb_dn *new_dn = NULL;

  new_dn = drs_ObjectIdentifier_to_dn(mem_ctx,

              ldb,

              nc);

  if (new_dn == NULL) {

    return LDB_ERR_INVALID_DN_SYNTAX;

  }

  ret = dsdb_normalise_dn_and_find_nc_root(ldb,

             mem_ctx,

             new_dn,

             normalised_dn,

             nc_root);

  if (ret != LDB_SUCCESS) {

    /*

     * dsdb_normalise_dn_and_find_nc_root() sets LDB error

     * strings, and the functions it calls do also

     */

    DBG_NOTICE("Failed to find DN \"%s\" -> \"%s\" for normalisation: %s (%s)\n",

         drs_ObjectIdentifier_to_debug_string(mem_ctx, nc),

         ldb_dn_get_extended_linearized(mem_ctx, new_dn, 1),

         ldb_errstring(ldb),

         ldb_strerror(ret));

  }

  TALLOC_FREE(new_dn);

  return ret;

}