/src/postgres/src/backend/libpq/hba.c

Source
/*-------------------------------------------------------------------------
 *
 * hba.c
 *    Routines to handle host based authentication (that's the scheme
 *    wherein you authenticate a user by seeing what IP address the system
 *    says he comes from and choosing authentication method based on it).
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/libpq/hba.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include <ctype.h>
#include <pwd.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#include "catalog/pg_collation.h"
#include "common/ip.h"
#include "common/string.h"
#include "libpq/hba.h"
#include "libpq/ifaddr.h"
#include "libpq/libpq-be.h"
#include "libpq/oauth.h"
#include "postmaster/postmaster.h"
#include "regex/regex.h"
#include "replication/walsender.h"
#include "storage/fd.h"
#include "utils/acl.h"
#include "utils/conffiles.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/varlena.h"

#ifdef USE_LDAP
#ifdef WIN32
#include <winldap.h>
#else
#include <ldap.h>
#endif
#endif


/* callback data for check_network_callback */
typedef struct check_network_data
{
  IPCompareMethod method;   /* test method */
  SockAddr   *raddr;      /* client's actual address */
  bool    result;     /* set to true if match */
} check_network_data;

typedef struct
{
  const char *filename;
  int     linenum;
} tokenize_error_callback_arg;

#define token_has_regexp(t) (t->regex != NULL)
#define token_is_member_check(t)  (!t->quoted && t->string[0] == '+')
#define token_is_keyword(t, k)  (!t->quoted && strcmp(t->string, k) == 0)
#define token_matches(t, k)  (strcmp(t->string, k) == 0)
#define token_matches_insensitive(t,k) (pg_strcasecmp(t->string, k) == 0)

/*
 * Memory context holding the list of TokenizedAuthLines when parsing
 * HBA or ident configuration files.  This is created when opening the first
 * file (depth of CONF_FILE_START_DEPTH).
 */
static MemoryContext tokenize_context = NULL;

/*
 * pre-parsed content of HBA config file: list of HbaLine structs.
 * parsed_hba_context is the memory context where it lives.
 */
static List *parsed_hba_lines = NIL;
static MemoryContext parsed_hba_context = NULL;

/*
 * pre-parsed content of ident mapping file: list of IdentLine structs.
 * parsed_ident_context is the memory context where it lives.
 */
static List *parsed_ident_lines = NIL;
static MemoryContext parsed_ident_context = NULL;

/*
 * The following character array represents the names of the authentication
 * methods that are supported by PostgreSQL.
 *
 * Note: keep this in sync with the UserAuth enum in hba.h.
 */
static const char *const UserAuthName[] =
{
  "reject",
  "implicit reject",      /* Not a user-visible option */
  "trust",
  "ident",
  "password",
  "md5",
  "scram-sha-256",
  "gss",
  "sspi",
  "pam",
  "bsd",
  "ldap",
  "cert",
  "peer",
  "oauth",
};

/*
 * Make sure UserAuthName[] tracks additions to the UserAuth enum
 */
StaticAssertDecl(lengthof(UserAuthName) == USER_AUTH_LAST + 1,
         "UserAuthName[] must match the UserAuth enum");


static List *tokenize_expand_file(List *tokens, const char *outer_filename,
                  const char *inc_filename, int elevel,
                  int depth, char **err_msg);
static bool parse_hba_auth_opt(char *name, char *val, HbaLine *hbaline,
                 int elevel, char **err_msg);
static int  regcomp_auth_token(AuthToken *token, char *filename, int line_num,
                 char **err_msg, int elevel);
static int  regexec_auth_token(const char *match, AuthToken *token,
                 size_t nmatch, regmatch_t pmatch[]);
static void tokenize_error_callback(void *arg);


static bool
pg_isblank(const char c)
{
  /* don't accept non-ASCII data */
  return (!IS_HIGHBIT_SET(c) && isblank(c));
}


/*
 * Grab one token out of the string pointed to by *lineptr.
 *
 * Tokens are strings of non-blank characters bounded by blank characters,
 * commas, beginning of line, and end of line.  Blank means space or tab.
 *
 * Tokens can be delimited by double quotes (this allows the inclusion of
 * commas, blanks, and '#', but not newlines).  As in SQL, write two
 * double-quotes to represent a double quote.
 *
 * Comments (started by an unquoted '#') are skipped, i.e. the remainder
 * of the line is ignored.
 *
 * (Note that line continuation processing happens before tokenization.
 * Thus, if a continuation occurs within quoted text or a comment, the
 * quoted text or comment is considered to continue to the next line.)
 *
 * The token, if any, is returned into buf (replacing any previous
 * contents), and *lineptr is advanced past the token.
 *
 * Also, we set *initial_quote to indicate whether there was quoting before
 * the first character.  (We use that to prevent "@x" from being treated
 * as a file inclusion request.  Note that @"x" should be so treated;
 * we want to allow that to support embedded spaces in file paths.)
 *
 * We set *terminating_comma to indicate whether the token is terminated by a
 * comma (which is not returned, nor advanced over).
 *
 * The only possible error condition is lack of terminating quote, but we
 * currently do not detect that, but just return the rest of the line.
 *
 * If successful: store dequoted token in buf and return true.
 * If no more tokens on line: set buf to empty and return false.
 */
static bool
next_token(char **lineptr, StringInfo buf,
       bool *initial_quote, bool *terminating_comma)
{
  int     c;
  bool    in_quote = false;
  bool    was_quote = false;
  bool    saw_quote = false;

  /* Initialize output parameters */
  resetStringInfo(buf);
  *initial_quote = false;
  *terminating_comma = false;

  /* Move over any whitespace and commas preceding the next token */
  while ((c = (*(*lineptr)++)) != '\0' && (pg_isblank(c) || c == ','))
    ;

  /*
   * Build a token in buf of next characters up to EOL, unquoted comma, or
   * unquoted whitespace.
   */
  while (c != '\0' &&
       (!pg_isblank(c) || in_quote))
  {
    /* skip comments to EOL */
    if (c == '#' && !in_quote)
    {
      while ((c = (*(*lineptr)++)) != '\0')
        ;
      break;
    }

    /* we do not pass back a terminating comma in the token */
    if (c == ',' && !in_quote)
    {
      *terminating_comma = true;
      break;
    }

    if (c != '"' || was_quote)
      appendStringInfoChar(buf, c);

    /* Literal double-quote is two double-quotes */
    if (in_quote && c == '"')
      was_quote = !was_quote;
    else
      was_quote = false;

    if (c == '"')
    {
      in_quote = !in_quote;
      saw_quote = true;
      if (buf->len == 0)
        *initial_quote = true;
    }

    c = *(*lineptr)++;
  }

  /*
   * Un-eat the char right after the token (critical in case it is '\0',
   * else next call will read past end of string).
   */
  (*lineptr)--;

  return (saw_quote || buf->len > 0);
}

/*
 * Construct a palloc'd AuthToken struct, copying the given string.
 */
static AuthToken *
make_auth_token(const char *token, bool quoted)
{
  AuthToken  *authtoken;
  int     toklen;

  toklen = strlen(token);
  /* we copy string into same palloc block as the struct */
  authtoken = (AuthToken *) palloc0(sizeof(AuthToken) + toklen + 1);
  authtoken->string = (char *) authtoken + sizeof(AuthToken);
  authtoken->quoted = quoted;
  authtoken->regex = NULL;
  memcpy(authtoken->string, token, toklen + 1);

  return authtoken;
}

/*
 * Free an AuthToken, that may include a regular expression that needs
 * to be cleaned up explicitly.
 */
static void
free_auth_token(AuthToken *token)
{
  if (token_has_regexp(token))
    pg_regfree(token->regex);
}

/*
 * Copy a AuthToken struct into freshly palloc'd memory.
 */
static AuthToken *
copy_auth_token(AuthToken *in)
{
  AuthToken  *out = make_auth_token(in->string, in->quoted);

  return out;
}

/*
 * Compile the regular expression and store it in the AuthToken given in
 * input.  Returns the result of pg_regcomp().  On error, the details are
 * stored in "err_msg".
 */
static int
regcomp_auth_token(AuthToken *token, char *filename, int line_num,
           char **err_msg, int elevel)
{
  pg_wchar   *wstr;
  int     wlen;
  int     rc;

  Assert(token->regex == NULL);

  if (token->string[0] != '/')
    return 0;       /* nothing to compile */

  token->regex = palloc0_object(regex_t);
  wstr = palloc((strlen(token->string + 1) + 1) * sizeof(pg_wchar));
  wlen = pg_mb2wchar_with_len(token->string + 1,
                wstr, strlen(token->string + 1));

  rc = pg_regcomp(token->regex, wstr, wlen, REG_ADVANCED, C_COLLATION_OID);

  if (rc)
  {
    char    errstr[100];

    pg_regerror(rc, token->regex, errstr, sizeof(errstr));
    ereport(elevel,
        (errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
         errmsg("invalid regular expression \"%s\": %s",
            token->string + 1, errstr),
         errcontext("line %d of configuration file \"%s\"",
              line_num, filename)));

    *err_msg = psprintf("invalid regular expression \"%s\": %s",
              token->string + 1, errstr);
  }

  pfree(wstr);
  return rc;
}

/*
 * Execute a regular expression computed in an AuthToken, checking for a match
 * with the string specified in "match".  The caller may optionally give an
 * array to store the matches.  Returns the result of pg_regexec().
 */
static int
regexec_auth_token(const char *match, AuthToken *token, size_t nmatch,
           regmatch_t pmatch[])
{
  pg_wchar   *wmatchstr;
  int     wmatchlen;
  int     r;

  Assert(token->string[0] == '/' && token->regex);

  wmatchstr = palloc((strlen(match) + 1) * sizeof(pg_wchar));
  wmatchlen = pg_mb2wchar_with_len(match, wmatchstr, strlen(match));

  r = pg_regexec(token->regex, wmatchstr, wmatchlen, 0, NULL, nmatch, pmatch, 0);

  pfree(wmatchstr);
  return r;
}

/*
 * Tokenize one HBA field from a line, handling file inclusion and comma lists.
 *
 * filename: current file's pathname (needed to resolve relative pathnames)
 * *lineptr: current line pointer, which will be advanced past field
 *
 * In event of an error, log a message at ereport level elevel, and also
 * set *err_msg to a string describing the error.  Note that the result
 * may be non-NIL anyway, so *err_msg must be tested to determine whether
 * there was an error.
 *
 * The result is a List of AuthToken structs, one for each token in the field,
 * or NIL if we reached EOL.
 */
static List *
next_field_expand(const char *filename, char **lineptr,
          int elevel, int depth, char **err_msg)
{
  StringInfoData buf;
  bool    trailing_comma;
  bool    initial_quote;
  List     *tokens = NIL;

  initStringInfo(&buf);

  do
  {
    if (!next_token(lineptr, &buf,
            &initial_quote, &trailing_comma))
      break;

    /* Is this referencing a file? */
    if (!initial_quote && buf.len > 1 && buf.data[0] == '@')
      tokens = tokenize_expand_file(tokens, filename, buf.data + 1,
                      elevel, depth + 1, err_msg);
    else
    {
      MemoryContext oldcxt;

      /*
       * lappend() may do its own allocations, so move to the context
       * for the list of tokens.
       */
      oldcxt = MemoryContextSwitchTo(tokenize_context);
      tokens = lappend(tokens, make_auth_token(buf.data, initial_quote));
      MemoryContextSwitchTo(oldcxt);
    }
  } while (trailing_comma && (*err_msg == NULL));

  pfree(buf.data);

  return tokens;
}

/*
 * tokenize_include_file
 *    Include a file from another file into an hba "field".
 *
 * Opens and tokenises a file included from another authentication file
 * with one of the include records ("include", "include_if_exists" or
 * "include_dir"), and assign all values found to an existing list of
 * list of AuthTokens.
 *
 * All new tokens are allocated in the memory context dedicated to the
 * tokenization, aka tokenize_context.
 *
 * If missing_ok is true, ignore a missing file.
 *
 * In event of an error, log a message at ereport level elevel, and also
 * set *err_msg to a string describing the error.  Note that the result
 * may be non-NIL anyway, so *err_msg must be tested to determine whether
 * there was an error.
 */
static void
tokenize_include_file(const char *outer_filename,
            const char *inc_filename,
            List **tok_lines,
            int elevel,
            int depth,
            bool missing_ok,
            char **err_msg)
{
  char     *inc_fullname;
  FILE     *inc_file;

  inc_fullname = AbsoluteConfigLocation(inc_filename, outer_filename);
  inc_file = open_auth_file(inc_fullname, elevel, depth, err_msg);

  if (!inc_file)
  {
    if (errno == ENOENT && missing_ok)
    {
      ereport(elevel,
          (errmsg("skipping missing authentication file \"%s\"",
              inc_fullname)));
      *err_msg = NULL;
      pfree(inc_fullname);
      return;
    }

    /* error in err_msg, so leave and report */
    pfree(inc_fullname);
    Assert(err_msg);
    return;
  }

  tokenize_auth_file(inc_fullname, inc_file, tok_lines, elevel,
             depth);
  free_auth_file(inc_file, depth);
  pfree(inc_fullname);
}

/*
 * tokenize_expand_file
 *    Expand a file included from another file into an hba "field"
 *
 * Opens and tokenises a file included from another HBA config file with @,
 * and returns all values found therein as a flat list of AuthTokens.  If a
 * @-token or include record is found, recursively expand it.  The newly
 * read tokens are appended to "tokens" (so that foo,bar,@baz does what you
 * expect).  All new tokens are allocated in the memory context dedicated
 * to the list of TokenizedAuthLines, aka tokenize_context.
 *
 * In event of an error, log a message at ereport level elevel, and also
 * set *err_msg to a string describing the error.  Note that the result
 * may be non-NIL anyway, so *err_msg must be tested to determine whether
 * there was an error.
 */
static List *
tokenize_expand_file(List *tokens,
           const char *outer_filename,
           const char *inc_filename,
           int elevel,
           int depth,
           char **err_msg)
{
  char     *inc_fullname;
  FILE     *inc_file;
  List     *inc_lines = NIL;
  ListCell   *inc_line;

  inc_fullname = AbsoluteConfigLocation(inc_filename, outer_filename);
  inc_file = open_auth_file(inc_fullname, elevel, depth, err_msg);

  if (inc_file == NULL)
  {
    /* error already logged */
    pfree(inc_fullname);
    return tokens;
  }

  /*
   * There is possible recursion here if the file contains @ or an include
   * record.
   */
  tokenize_auth_file(inc_fullname, inc_file, &inc_lines, elevel,
             depth);

  pfree(inc_fullname);

  /*
   * Move all the tokens found in the file to the tokens list.  These are
   * already saved in tokenize_context.
   */
  foreach(inc_line, inc_lines)
  {
    TokenizedAuthLine *tok_line = (TokenizedAuthLine *) lfirst(inc_line);
    ListCell   *inc_field;

    /* If any line has an error, propagate that up to caller */
    if (tok_line->err_msg)
    {
      *err_msg = pstrdup(tok_line->err_msg);
      break;
    }

    foreach(inc_field, tok_line->fields)
    {
      List     *inc_tokens = lfirst(inc_field);
      ListCell   *inc_token;

      foreach(inc_token, inc_tokens)
      {
        AuthToken  *token = lfirst(inc_token);
        MemoryContext oldcxt;

        /*
         * lappend() may do its own allocations, so move to the
         * context for the list of tokens.
         */
        oldcxt = MemoryContextSwitchTo(tokenize_context);
        tokens = lappend(tokens, token);
        MemoryContextSwitchTo(oldcxt);
      }
    }
  }

  free_auth_file(inc_file, depth);
  return tokens;
}

/*
 * free_auth_file
 *    Free a file opened by open_auth_file().
 */
void
free_auth_file(FILE *file, int depth)
{
  FreeFile(file);

  /* If this is the last cleanup, remove the tokenization context */
  if (depth == CONF_FILE_START_DEPTH)
  {
    MemoryContextDelete(tokenize_context);
    tokenize_context = NULL;
  }
}

/*
 * open_auth_file
 *    Open the given file.
 *
 * filename: the absolute path to the target file
 * elevel: message logging level
 * depth: recursion level when opening the file
 * err_msg: details about the error
 *
 * Return value is the opened file.  On error, returns NULL with details
 * about the error stored in "err_msg".
 */
FILE *
open_auth_file(const char *filename, int elevel, int depth,
         char **err_msg)
{
  FILE     *file;

  /*
   * Reject too-deep include nesting depth.  This is just a safety check to
   * avoid dumping core due to stack overflow if an include file loops back
   * to itself.  The maximum nesting depth is pretty arbitrary.
   */
  if (depth > CONF_FILE_MAX_DEPTH)
  {
    ereport(elevel,
        (errcode_for_file_access(),
         errmsg("could not open file \"%s\": maximum nesting depth exceeded",
            filename)));
    if (err_msg)
      *err_msg = psprintf("could not open file \"%s\": maximum nesting depth exceeded",
                filename);
    return NULL;
  }

  file = AllocateFile(filename, "r");
  if (file == NULL)
  {
    int     save_errno = errno;

    ereport(elevel,
        (errcode_for_file_access(),
         errmsg("could not open file \"%s\": %m",
            filename)));
    if (err_msg)
    {
      errno = save_errno;
      *err_msg = psprintf("could not open file \"%s\": %m",
                filename);
    }
    /* the caller may care about some specific errno */
    errno = save_errno;
    return NULL;
  }

  /*
   * When opening the top-level file, create the memory context used for the
   * tokenization.  This will be closed with this file when coming back to
   * this level of cleanup.
   */
  if (depth == CONF_FILE_START_DEPTH)
  {
    /*
     * A context may be present, but assume that it has been eliminated
     * already.
     */
    tokenize_context = AllocSetContextCreate(CurrentMemoryContext,
                         "tokenize_context",
                         ALLOCSET_START_SMALL_SIZES);
  }

  return file;
}

/*
 * error context callback for tokenize_auth_file()
 */
static void
tokenize_error_callback(void *arg)
{
  tokenize_error_callback_arg *callback_arg = (tokenize_error_callback_arg *) arg;

  errcontext("line %d of configuration file \"%s\"",
         callback_arg->linenum, callback_arg->filename);
}

/*
 * tokenize_auth_file
 *    Tokenize the given file.
 *
 * The output is a list of TokenizedAuthLine structs; see the struct definition
 * in libpq/hba.h.  This is the central piece in charge of parsing the
 * authentication files.  All the operations of this function happen in its own
 * local memory context, easing the cleanup of anything allocated here.  This
 * matters a lot when reloading authentication files in the postmaster.
 *
 * filename: the absolute path to the target file
 * file: the already-opened target file
 * tok_lines: receives output list, saved into tokenize_context
 * elevel: message logging level
 * depth: level of recursion when tokenizing the target file
 *
 * Errors are reported by logging messages at ereport level elevel and by
 * adding TokenizedAuthLine structs containing non-null err_msg fields to the
 * output list.
 */
void
tokenize_auth_file(const char *filename, FILE *file, List **tok_lines,
           int elevel, int depth)
{
  int     line_number = 1;
  StringInfoData buf;
  MemoryContext linecxt;
  MemoryContext funccxt;    /* context of this function's caller */
  ErrorContextCallback tokenerrcontext;
  tokenize_error_callback_arg callback_arg;

  Assert(tokenize_context);

  callback_arg.filename = filename;
  callback_arg.linenum = line_number;

  tokenerrcontext.callback = tokenize_error_callback;
  tokenerrcontext.arg = &callback_arg;
  tokenerrcontext.previous = error_context_stack;
  error_context_stack = &tokenerrcontext;

  /*
   * Do all the local tokenization in its own context, to ease the cleanup
   * of any memory allocated while tokenizing.
   */
  linecxt = AllocSetContextCreate(CurrentMemoryContext,
                  "tokenize_auth_file",
                  ALLOCSET_SMALL_SIZES);
  funccxt = MemoryContextSwitchTo(linecxt);

  initStringInfo(&buf);

  if (depth == CONF_FILE_START_DEPTH)
    *tok_lines = NIL;

  while (!feof(file) && !ferror(file))
  {
    TokenizedAuthLine *tok_line;
    MemoryContext oldcxt;
    char     *lineptr;
    List     *current_line = NIL;
    char     *err_msg = NULL;
    int     last_backslash_buflen = 0;
    int     continuations = 0;

    /* Collect the next input line, handling backslash continuations */
    resetStringInfo(&buf);

    while (pg_get_line_append(file, &buf, NULL))
    {
      /* Strip trailing newline, including \r in case we're on Windows */
      buf.len = pg_strip_crlf(buf.data);

      /*
       * Check for backslash continuation.  The backslash must be after
       * the last place we found a continuation, else two backslashes
       * followed by two \n's would behave surprisingly.
       */
      if (buf.len > last_backslash_buflen &&
        buf.data[buf.len - 1] == '\\')
      {
        /* Continuation, so strip it and keep reading */
        buf.data[--buf.len] = '\0';
        last_backslash_buflen = buf.len;
        continuations++;
        continue;
      }

      /* Nope, so we have the whole line */
      break;
    }

    if (ferror(file))
    {
      /* I/O error! */
      int     save_errno = errno;

      ereport(elevel,
          (errcode_for_file_access(),
           errmsg("could not read file \"%s\": %m", filename)));
      errno = save_errno;
      err_msg = psprintf("could not read file \"%s\": %m",
                 filename);
      break;
    }

    /* Parse fields */
    lineptr = buf.data;
    while (*lineptr && err_msg == NULL)
    {
      List     *current_field;

      current_field = next_field_expand(filename, &lineptr,
                        elevel, depth, &err_msg);
      /* add field to line, unless we are at EOL or comment start */
      if (current_field != NIL)
      {
        /*
         * lappend() may do its own allocations, so move to the
         * context for the list of tokens.
         */
        oldcxt = MemoryContextSwitchTo(tokenize_context);
        current_line = lappend(current_line, current_field);
        MemoryContextSwitchTo(oldcxt);
      }
    }

    /*
     * Reached EOL; no need to emit line to TokenizedAuthLine list if it's
     * boring.
     */
    if (current_line == NIL && err_msg == NULL)
      goto next_line;

    /* If the line is valid, check if that's an include directive */
    if (err_msg == NULL && list_length(current_line) == 2)
    {
      AuthToken  *first,
             *second;

      first = linitial(linitial_node(List, current_line));
      second = linitial(lsecond_node(List, current_line));

      if (strcmp(first->string, "include") == 0)
      {
        tokenize_include_file(filename, second->string, tok_lines,
                    elevel, depth + 1, false, &err_msg);

        if (err_msg)
          goto process_line;

        /*
         * tokenize_auth_file() has taken care of creating the
         * TokenizedAuthLines.
         */
        goto next_line;
      }
      else if (strcmp(first->string, "include_dir") == 0)
      {
        char    **filenames;
        char     *dir_name = second->string;
        int     num_filenames;
        StringInfoData err_buf;

        filenames = GetConfFilesInDir(dir_name, filename, elevel,
                        &num_filenames, &err_msg);

        if (!filenames)
        {
          /* the error is in err_msg, so create an entry */
          goto process_line;
        }

        initStringInfo(&err_buf);
        for (int i = 0; i < num_filenames; i++)
        {
          tokenize_include_file(filename, filenames[i], tok_lines,
                      elevel, depth + 1, false, &err_msg);
          /* cumulate errors if any */
          if (err_msg)
          {
            if (err_buf.len > 0)
              appendStringInfoChar(&err_buf, '\n');
            appendStringInfoString(&err_buf, err_msg);
          }
        }

        /* clean up things */
        for (int i = 0; i < num_filenames; i++)
          pfree(filenames[i]);
        pfree(filenames);

        /*
         * If there were no errors, the line is fully processed,
         * bypass the general TokenizedAuthLine processing.
         */
        if (err_buf.len == 0)
          goto next_line;

        /* Otherwise, process the cumulated errors, if any. */
        err_msg = err_buf.data;
        goto process_line;
      }
      else if (strcmp(first->string, "include_if_exists") == 0)
      {

        tokenize_include_file(filename, second->string, tok_lines,
                    elevel, depth + 1, true, &err_msg);
        if (err_msg)
          goto process_line;

        /*
         * tokenize_auth_file() has taken care of creating the
         * TokenizedAuthLines.
         */
        goto next_line;
      }
    }

process_line:

    /*
     * General processing: report the error if any and emit line to the
     * TokenizedAuthLine.  This is saved in the memory context dedicated
     * to this list.
     */
    oldcxt = MemoryContextSwitchTo(tokenize_context);
    tok_line = palloc0_object(TokenizedAuthLine);
    tok_line->fields = current_line;
    tok_line->file_name = pstrdup(filename);
    tok_line->line_num = line_number;
    tok_line->raw_line = pstrdup(buf.data);
    tok_line->err_msg = err_msg ? pstrdup(err_msg) : NULL;
    *tok_lines = lappend(*tok_lines, tok_line);
    MemoryContextSwitchTo(oldcxt);

next_line:
    line_number += continuations + 1;
    callback_arg.linenum = line_number;
  }

  MemoryContextSwitchTo(funccxt);
  MemoryContextDelete(linecxt);

  error_context_stack = tokenerrcontext.previous;
}


/*
 * Does user belong to role?
 *
 * userid is the OID of the role given as the attempted login identifier.
 * We check to see if it is a member of the specified role name.
 */
static bool
is_member(Oid userid, const char *role)
{
  Oid     roleid;

  if (!OidIsValid(userid))
    return false;     /* if user not exist, say "no" */

  roleid = get_role_oid(role, true);

  if (!OidIsValid(roleid))
    return false;     /* if target role not exist, say "no" */

  /*
   * See if user is directly or indirectly a member of role. For this
   * purpose, a superuser is not considered to be automatically a member of
   * the role, so group auth only applies to explicit membership.
   */
  return is_member_of_role_nosuper(userid, roleid);
}

/*
 * Check AuthToken list for a match to role, allowing group names.
 *
 * Each AuthToken listed is checked one-by-one.  Keywords are processed
 * first (these cannot have regular expressions), followed by regular
 * expressions (if any), the case-insensitive match (if requested) and
 * the exact match.
 */
static bool
check_role(const char *role, Oid roleid, List *tokens, bool case_insensitive)
{
  ListCell   *cell;
  AuthToken  *tok;

  foreach(cell, tokens)
  {
    tok = lfirst(cell);
    if (token_is_member_check(tok))
    {
      if (is_member(roleid, tok->string + 1))
        return true;
    }
    else if (token_is_keyword(tok, "all"))
      return true;
    else if (token_has_regexp(tok))
    {
      if (regexec_auth_token(role, tok, 0, NULL) == REG_OKAY)
        return true;
    }
    else if (case_insensitive)
    {
      if (token_matches_insensitive(tok, role))
        return true;
    }
    else if (token_matches(tok, role))
      return true;
  }
  return false;
}

/*
 * Check to see if db/role combination matches AuthToken list.
 *
 * Each AuthToken listed is checked one-by-one.  Keywords are checked
 * first (these cannot have regular expressions), followed by regular
 * expressions (if any) and the exact match.
 */
static bool
check_db(const char *dbname, const char *role, Oid roleid, List *tokens)
{
  ListCell   *cell;
  AuthToken  *tok;

  foreach(cell, tokens)
  {
    tok = lfirst(cell);
    if (am_walsender && !am_db_walsender)
    {
      /*
       * physical replication walsender connections can only match
       * replication keyword
       */
      if (token_is_keyword(tok, "replication"))
        return true;
    }
    else if (token_is_keyword(tok, "all"))
      return true;
    else if (token_is_keyword(tok, "sameuser"))
    {
      if (strcmp(dbname, role) == 0)
        return true;
    }
    else if (token_is_keyword(tok, "samegroup") ||
         token_is_keyword(tok, "samerole"))
    {
      if (is_member(roleid, dbname))
        return true;
    }
    else if (token_is_keyword(tok, "replication"))
      continue;     /* never match this if not walsender */
    else if (token_has_regexp(tok))
    {
      if (regexec_auth_token(dbname, tok, 0, NULL) == REG_OKAY)
        return true;
    }
    else if (token_matches(tok, dbname))
      return true;
  }
  return false;
}

static bool
ipv4eq(struct sockaddr_in *a, struct sockaddr_in *b)
{
  return (a->sin_addr.s_addr == b->sin_addr.s_addr);
}

static bool
ipv6eq(struct sockaddr_in6 *a, struct sockaddr_in6 *b)
{
  int     i;

  for (i = 0; i < 16; i++)
    if (a->sin6_addr.s6_addr[i] != b->sin6_addr.s6_addr[i])
      return false;

  return true;
}

/*
 * Check whether host name matches pattern.
 */
static bool
hostname_match(const char *pattern, const char *actual_hostname)
{
  if (pattern[0] == '.')   /* suffix match */
  {
    size_t    plen = strlen(pattern);
    size_t    hlen = strlen(actual_hostname);

    if (hlen < plen)
      return false;

    return (pg_strcasecmp(pattern, actual_hostname + (hlen - plen)) == 0);
  }
  else
    return (pg_strcasecmp(pattern, actual_hostname) == 0);
}

/*
 * Check to see if a connecting IP matches a given host name.
 */
static bool
check_hostname(Port *port, const char *hostname)
{
  struct addrinfo *gai_result,
         *gai;
  int     ret;
  bool    found;

  /* Quick out if remote host name already known bad */
  if (port->remote_hostname_resolv < 0)
    return false;

  /* Lookup remote host name if not already done */
  if (!port->remote_hostname)
  {
    char    remote_hostname[NI_MAXHOST];

    ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
                 remote_hostname, sizeof(remote_hostname),
                 NULL, 0,
                 NI_NAMEREQD);
    if (ret != 0)
    {
      /* remember failure; don't complain in the postmaster log yet */
      port->remote_hostname_resolv = -2;
      port->remote_hostname_errcode = ret;
      return false;
    }

    port->remote_hostname = pstrdup(remote_hostname);
  }

  /* Now see if remote host name matches this pg_hba line */
  if (!hostname_match(hostname, port->remote_hostname))
    return false;

  /* If we already verified the forward lookup, we're done */
  if (port->remote_hostname_resolv == +1)
    return true;

  /* Lookup IP from host name and check against original IP */
  ret = getaddrinfo(port->remote_hostname, NULL, NULL, &gai_result);
  if (ret != 0)
  {
    /* remember failure; don't complain in the postmaster log yet */
    port->remote_hostname_resolv = -2;
    port->remote_hostname_errcode = ret;
    return false;
  }

  found = false;
  for (gai = gai_result; gai; gai = gai->ai_next)
  {
    if (gai->ai_addr->sa_family == port->raddr.addr.ss_family)
    {
      if (gai->ai_addr->sa_family == AF_INET)
      {
        if (ipv4eq((struct sockaddr_in *) gai->ai_addr,
               (struct sockaddr_in *) &port->raddr.addr))
        {
          found = true;
          break;
        }
      }
      else if (gai->ai_addr->sa_family == AF_INET6)
      {
        if (ipv6eq((struct sockaddr_in6 *) gai->ai_addr,
               (struct sockaddr_in6 *) &port->raddr.addr))
        {
          found = true;
          break;
        }
      }
    }
  }

  if (gai_result)
    freeaddrinfo(gai_result);

  if (!found)
    elog(DEBUG2, "pg_hba.conf host name \"%s\" rejected because address resolution did not return a match with IP address of client",
       hostname);

  port->remote_hostname_resolv = found ? +1 : -1;

  return found;
}

/*
 * Check to see if a connecting IP matches the given address and netmask.
 */
static bool
check_ip(SockAddr *raddr, struct sockaddr *addr, struct sockaddr *mask)
{
  if (raddr->addr.ss_family == addr->sa_family &&
    pg_range_sockaddr(&raddr->addr,
              (struct sockaddr_storage *) addr,
              (struct sockaddr_storage *) mask))
    return true;
  return false;
}

/*
 * pg_foreach_ifaddr callback: does client addr match this machine interface?
 */
static void
check_network_callback(struct sockaddr *addr, struct sockaddr *netmask,
             void *cb_data)
{
  check_network_data *cn = (check_network_data *) cb_data;
  struct sockaddr_storage mask;

  /* Already found a match? */
  if (cn->result)
    return;

  if (cn->method == ipCmpSameHost)
  {
    /* Make an all-ones netmask of appropriate length for family */
    pg_sockaddr_cidr_mask(&mask, NULL, addr->sa_family);
    cn->result = check_ip(cn->raddr, addr, (struct sockaddr *) &mask);
  }
  else
  {
    /* Use the netmask of the interface itself */
    cn->result = check_ip(cn->raddr, addr, netmask);
  }
}

/*
 * Use pg_foreach_ifaddr to check a samehost or samenet match
 */
static bool
check_same_host_or_net(SockAddr *raddr, IPCompareMethod method)
{
  check_network_data cn;

  cn.method = method;
  cn.raddr = raddr;
  cn.result = false;

  errno = 0;
  if (pg_foreach_ifaddr(check_network_callback, &cn) < 0)
  {
    ereport(LOG,
        (errmsg("error enumerating network interfaces: %m")));
    return false;
  }

  return cn.result;
}


/*
 * Macros used to check and report on invalid configuration options.
 * On error: log a message at level elevel, set *err_msg, and exit the function.
 * These macros are not as general-purpose as they look, because they know
 * what the calling function's error-exit value is.
 *
 * INVALID_AUTH_OPTION = reports when an option is specified for a method where it's
 *             not supported.
 * REQUIRE_AUTH_OPTION = same as INVALID_AUTH_OPTION, except it also checks if the
 *             method is actually the one specified. Used as a shortcut when
 *             the option is only valid for one authentication method.
 * MANDATORY_AUTH_ARG  = check if a required option is set for an authentication method,
 *             reporting error if it's not.
 */
#define INVALID_AUTH_OPTION(optname, validmethods) \
do { \
  ereport(elevel, \
      (errcode(ERRCODE_CONFIG_FILE_ERROR), \
       /* translator: the second %s is a list of auth methods */ \
       errmsg("authentication option \"%s\" is only valid for authentication methods %s", \
          optname, _(validmethods)), \
       errcontext("line %d of configuration file \"%s\"", \
          line_num, file_name))); \
  *err_msg = psprintf("authentication option \"%s\" is only valid for authentication methods %s", \
            optname, validmethods); \
  return false; \
} while (0)

#define REQUIRE_AUTH_OPTION(methodval, optname, validmethods) \
do { \
  if (hbaline->auth_method != methodval) \
    INVALID_AUTH_OPTION(optname, validmethods); \
} while (0)

#define MANDATORY_AUTH_ARG(argvar, argname, authname) \
do { \
  if (argvar == NULL) { \
    ereport(elevel, \
        (errcode(ERRCODE_CONFIG_FILE_ERROR), \
         errmsg("authentication method \"%s\" requires argument \"%s\" to be set", \
            authname, argname), \
         errcontext("line %d of configuration file \"%s\"", \
            line_num, file_name))); \
    *err_msg = psprintf("authentication method \"%s\" requires argument \"%s\" to be set", \
              authname, argname); \
    return NULL; \
  } \
} while (0)

/*
 * Macros for handling pg_ident problems, similar as above.
 *
 * IDENT_FIELD_ABSENT:
 * Reports when the given ident field ListCell is not populated.
 *
 * IDENT_MULTI_VALUE:
 * Reports when the given ident token List has more than one element.
 */
#define IDENT_FIELD_ABSENT(field) \
do { \
  if (!field) { \
    ereport(elevel, \
        (errcode(ERRCODE_CONFIG_FILE_ERROR), \
         errmsg("missing entry at end of line"), \
         errcontext("line %d of configuration file \"%s\"", \
              line_num, file_name))); \
    *err_msg = pstrdup("missing entry at end of line"); \
    return NULL; \
  } \
} while (0)

#define IDENT_MULTI_VALUE(tokens) \
do { \
  if (tokens->length > 1) { \
    ereport(elevel, \
        (errcode(ERRCODE_CONFIG_FILE_ERROR), \
         errmsg("multiple values in ident field"), \
         errcontext("line %d of configuration file \"%s\"", \
              line_num, file_name))); \
    *err_msg = pstrdup("multiple values in ident field"); \
    return NULL; \
  } \
} while (0)


/*
 * Parse one tokenised line from the hba config file and store the result in a
 * HbaLine structure.
 *
 * If parsing fails, log a message at ereport level elevel, store an error
 * string in tok_line->err_msg, and return NULL.  (Some non-error conditions
 * can also result in such messages.)
 *
 * Note: this function leaks memory when an error occurs.  Caller is expected
 * to have set a memory context that will be reset if this function returns
 * NULL.
 */
HbaLine *
parse_hba_line(TokenizedAuthLine *tok_line, int elevel)
{
  int     line_num = tok_line->line_num;
  char     *file_name = tok_line->file_name;
  char    **err_msg = &tok_line->err_msg;
  char     *str;
  struct addrinfo *gai_result;
  struct addrinfo hints;
  int     ret;
  char     *cidr_slash;
  char     *unsupauth;
  ListCell   *field;
  List     *tokens;
  ListCell   *tokencell;
  AuthToken  *token;
  HbaLine    *parsedline;

  parsedline = palloc0_object(HbaLine);
  parsedline->sourcefile = pstrdup(file_name);
  parsedline->linenumber = line_num;
  parsedline->rawline = pstrdup(tok_line->raw_line);

  /* Check the record type. */
  Assert(tok_line->fields != NIL);
  field = list_head(tok_line->fields);
  tokens = lfirst(field);
  if (tokens->length > 1)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("multiple values specified for connection type"),
         errhint("Specify exactly one connection type per line."),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "multiple values specified for connection type";
    return NULL;
  }
  token = linitial(tokens);
  if (strcmp(token->string, "local") == 0)
  {
    parsedline->conntype = ctLocal;
  }
  else if (strcmp(token->string, "host") == 0 ||
       strcmp(token->string, "hostssl") == 0 ||
       strcmp(token->string, "hostnossl") == 0 ||
       strcmp(token->string, "hostgssenc") == 0 ||
       strcmp(token->string, "hostnogssenc") == 0)
  {

    if (token->string[4] == 's') /* "hostssl" */
    {
      parsedline->conntype = ctHostSSL;
      /* Log a warning if SSL support is not active */
#ifdef USE_SSL
      if (!EnableSSL)
      {
        ereport(elevel,
            (errcode(ERRCODE_CONFIG_FILE_ERROR),
             errmsg("hostssl record cannot match because SSL is disabled"),
             errhint("Set \"ssl = on\" in postgresql.conf."),
             errcontext("line %d of configuration file \"%s\"",
                  line_num, file_name)));
        *err_msg = "hostssl record cannot match because SSL is disabled";
      }
#else
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("hostssl record cannot match because SSL is not supported by this build"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "hostssl record cannot match because SSL is not supported by this build";
#endif
    }
    else if (token->string[4] == 'g') /* "hostgssenc" */
    {
      parsedline->conntype = ctHostGSS;
#ifndef ENABLE_GSS
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("hostgssenc record cannot match because GSSAPI is not supported by this build"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "hostgssenc record cannot match because GSSAPI is not supported by this build";
#endif
    }
    else if (token->string[4] == 'n' && token->string[6] == 's')
      parsedline->conntype = ctHostNoSSL;
    else if (token->string[4] == 'n' && token->string[6] == 'g')
      parsedline->conntype = ctHostNoGSS;
    else
    {
      /* "host" */
      parsedline->conntype = ctHost;
    }
  }             /* record type */
  else
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("invalid connection type \"%s\"",
            token->string),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = psprintf("invalid connection type \"%s\"", token->string);
    return NULL;
  }

  /* Get the databases. */
  field = lnext(tok_line->fields, field);
  if (!field)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("end-of-line before database specification"),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "end-of-line before database specification";
    return NULL;
  }
  parsedline->databases = NIL;
  tokens = lfirst(field);
  foreach(tokencell, tokens)
  {
    AuthToken  *tok = copy_auth_token(lfirst(tokencell));

    /* Compile a regexp for the database token, if necessary */
    if (regcomp_auth_token(tok, file_name, line_num, err_msg, elevel))
      return NULL;

    parsedline->databases = lappend(parsedline->databases, tok);
  }

  /* Get the roles. */
  field = lnext(tok_line->fields, field);
  if (!field)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("end-of-line before role specification"),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "end-of-line before role specification";
    return NULL;
  }
  parsedline->roles = NIL;
  tokens = lfirst(field);
  foreach(tokencell, tokens)
  {
    AuthToken  *tok = copy_auth_token(lfirst(tokencell));

    /* Compile a regexp from the role token, if necessary */
    if (regcomp_auth_token(tok, file_name, line_num, err_msg, elevel))
      return NULL;

    parsedline->roles = lappend(parsedline->roles, tok);
  }

  if (parsedline->conntype != ctLocal)
  {
    /* Read the IP address field. (with or without CIDR netmask) */
    field = lnext(tok_line->fields, field);
    if (!field)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("end-of-line before IP address specification"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "end-of-line before IP address specification";
      return NULL;
    }
    tokens = lfirst(field);
    if (tokens->length > 1)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("multiple values specified for host address"),
           errhint("Specify one address range per line."),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "multiple values specified for host address";
      return NULL;
    }
    token = linitial(tokens);

    if (token_is_keyword(token, "all"))
    {
      parsedline->ip_cmp_method = ipCmpAll;
    }
    else if (token_is_keyword(token, "samehost"))
    {
      /* Any IP on this host is allowed to connect */
      parsedline->ip_cmp_method = ipCmpSameHost;
    }
    else if (token_is_keyword(token, "samenet"))
    {
      /* Any IP on the host's subnets is allowed to connect */
      parsedline->ip_cmp_method = ipCmpSameNet;
    }
    else
    {
      /* IP and netmask are specified */
      parsedline->ip_cmp_method = ipCmpMask;

      /* need a modifiable copy of token */
      str = pstrdup(token->string);

      /* Check if it has a CIDR suffix and if so isolate it */
      cidr_slash = strchr(str, '/');
      if (cidr_slash)
        *cidr_slash = '\0';

      /* Get the IP address either way */
      hints.ai_flags = AI_NUMERICHOST;
      hints.ai_family = AF_UNSPEC;
      hints.ai_socktype = 0;
      hints.ai_protocol = 0;
      hints.ai_addrlen = 0;
      hints.ai_canonname = NULL;
      hints.ai_addr = NULL;
      hints.ai_next = NULL;

      ret = pg_getaddrinfo_all(str, NULL, &hints, &gai_result);
      if (ret == 0 && gai_result)
      {
        memcpy(&parsedline->addr, gai_result->ai_addr,
             gai_result->ai_addrlen);
        parsedline->addrlen = gai_result->ai_addrlen;
      }
      else if (ret == EAI_NONAME)
        parsedline->hostname = str;
      else
      {
        ereport(elevel,
            (errcode(ERRCODE_CONFIG_FILE_ERROR),
             errmsg("invalid IP address \"%s\": %s",
                str, gai_strerror(ret)),
             errcontext("line %d of configuration file \"%s\"",
                  line_num, file_name)));
        *err_msg = psprintf("invalid IP address \"%s\": %s",
                  str, gai_strerror(ret));
        if (gai_result)
          pg_freeaddrinfo_all(hints.ai_family, gai_result);
        return NULL;
      }

      pg_freeaddrinfo_all(hints.ai_family, gai_result);

      /* Get the netmask */
      if (cidr_slash)
      {
        if (parsedline->hostname)
        {
          ereport(elevel,
              (errcode(ERRCODE_CONFIG_FILE_ERROR),
               errmsg("specifying both host name and CIDR mask is invalid: \"%s\"",
                  token->string),
               errcontext("line %d of configuration file \"%s\"",
                    line_num, file_name)));
          *err_msg = psprintf("specifying both host name and CIDR mask is invalid: \"%s\"",
                    token->string);
          return NULL;
        }

        if (pg_sockaddr_cidr_mask(&parsedline->mask, cidr_slash + 1,
                      parsedline->addr.ss_family) < 0)
        {
          ereport(elevel,
              (errcode(ERRCODE_CONFIG_FILE_ERROR),
               errmsg("invalid CIDR mask in address \"%s\"",
                  token->string),
               errcontext("line %d of configuration file \"%s\"",
                    line_num, file_name)));
          *err_msg = psprintf("invalid CIDR mask in address \"%s\"",
                    token->string);
          return NULL;
        }
        parsedline->masklen = parsedline->addrlen;
        pfree(str);
      }
      else if (!parsedline->hostname)
      {
        /* Read the mask field. */
        pfree(str);
        field = lnext(tok_line->fields, field);
        if (!field)
        {
          ereport(elevel,
              (errcode(ERRCODE_CONFIG_FILE_ERROR),
               errmsg("end-of-line before netmask specification"),
               errhint("Specify an address range in CIDR notation, or provide a separate netmask."),
               errcontext("line %d of configuration file \"%s\"",
                    line_num, file_name)));
          *err_msg = "end-of-line before netmask specification";
          return NULL;
        }
        tokens = lfirst(field);
        if (tokens->length > 1)
        {
          ereport(elevel,
              (errcode(ERRCODE_CONFIG_FILE_ERROR),
               errmsg("multiple values specified for netmask"),
               errcontext("line %d of configuration file \"%s\"",
                    line_num, file_name)));
          *err_msg = "multiple values specified for netmask";
          return NULL;
        }
        token = linitial(tokens);

        ret = pg_getaddrinfo_all(token->string, NULL,
                     &hints, &gai_result);
        if (ret || !gai_result)
        {
          ereport(elevel,
              (errcode(ERRCODE_CONFIG_FILE_ERROR),
               errmsg("invalid IP mask \"%s\": %s",
                  token->string, gai_strerror(ret)),
               errcontext("line %d of configuration file \"%s\"",
                    line_num, file_name)));
          *err_msg = psprintf("invalid IP mask \"%s\": %s",
                    token->string, gai_strerror(ret));
          if (gai_result)
            pg_freeaddrinfo_all(hints.ai_family, gai_result);
          return NULL;
        }

        memcpy(&parsedline->mask, gai_result->ai_addr,
             gai_result->ai_addrlen);
        parsedline->masklen = gai_result->ai_addrlen;
        pg_freeaddrinfo_all(hints.ai_family, gai_result);

        if (parsedline->addr.ss_family != parsedline->mask.ss_family)
        {
          ereport(elevel,
              (errcode(ERRCODE_CONFIG_FILE_ERROR),
               errmsg("IP address and mask do not match"),
               errcontext("line %d of configuration file \"%s\"",
                    line_num, file_name)));
          *err_msg = "IP address and mask do not match";
          return NULL;
        }
      }
    }
  }             /* != ctLocal */

  /* Get the authentication method */
  field = lnext(tok_line->fields, field);
  if (!field)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("end-of-line before authentication method"),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "end-of-line before authentication method";
    return NULL;
  }
  tokens = lfirst(field);
  if (tokens->length > 1)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("multiple values specified for authentication type"),
         errhint("Specify exactly one authentication type per line."),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "multiple values specified for authentication type";
    return NULL;
  }
  token = linitial(tokens);

  unsupauth = NULL;
  if (strcmp(token->string, "trust") == 0)
    parsedline->auth_method = uaTrust;
  else if (strcmp(token->string, "ident") == 0)
    parsedline->auth_method = uaIdent;
  else if (strcmp(token->string, "peer") == 0)
    parsedline->auth_method = uaPeer;
  else if (strcmp(token->string, "password") == 0)
    parsedline->auth_method = uaPassword;
  else if (strcmp(token->string, "gss") == 0)
#ifdef ENABLE_GSS
    parsedline->auth_method = uaGSS;
#else
    unsupauth = "gss";
#endif
  else if (strcmp(token->string, "sspi") == 0)
#ifdef ENABLE_SSPI
    parsedline->auth_method = uaSSPI;
#else
    unsupauth = "sspi";
#endif
  else if (strcmp(token->string, "reject") == 0)
    parsedline->auth_method = uaReject;
  else if (strcmp(token->string, "md5") == 0)
    parsedline->auth_method = uaMD5;
  else if (strcmp(token->string, "scram-sha-256") == 0)
    parsedline->auth_method = uaSCRAM;
  else if (strcmp(token->string, "pam") == 0)
#ifdef USE_PAM
    parsedline->auth_method = uaPAM;
#else
    unsupauth = "pam";
#endif
  else if (strcmp(token->string, "bsd") == 0)
#ifdef USE_BSD_AUTH
    parsedline->auth_method = uaBSD;
#else
    unsupauth = "bsd";
#endif
  else if (strcmp(token->string, "ldap") == 0)
#ifdef USE_LDAP
    parsedline->auth_method = uaLDAP;
#else
    unsupauth = "ldap";
#endif
  else if (strcmp(token->string, "cert") == 0)
#ifdef USE_SSL
    parsedline->auth_method = uaCert;
#else
    unsupauth = "cert";
#endif
  else if (strcmp(token->string, "oauth") == 0)
    parsedline->auth_method = uaOAuth;
  else
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("invalid authentication method \"%s\"",
            token->string),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = psprintf("invalid authentication method \"%s\"",
              token->string);
    return NULL;
  }

  if (unsupauth)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("invalid authentication method \"%s\": not supported by this build",
            token->string),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = psprintf("invalid authentication method \"%s\": not supported by this build",
              token->string);
    return NULL;
  }

  /*
   * XXX: When using ident on local connections, change it to peer, for
   * backwards compatibility.
   */
  if (parsedline->conntype == ctLocal &&
    parsedline->auth_method == uaIdent)
    parsedline->auth_method = uaPeer;

  /* Invalid authentication combinations */
  if (parsedline->conntype == ctLocal &&
    parsedline->auth_method == uaGSS)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("gssapi authentication is not supported on local sockets"),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "gssapi authentication is not supported on local sockets";
    return NULL;
  }

  if (parsedline->conntype != ctLocal &&
    parsedline->auth_method == uaPeer)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("peer authentication is only supported on local sockets"),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "peer authentication is only supported on local sockets";
    return NULL;
  }

  /*
   * SSPI authentication can never be enabled on ctLocal connections,
   * because it's only supported on Windows, where ctLocal isn't supported.
   */


  if (parsedline->conntype != ctHostSSL &&
    parsedline->auth_method == uaCert)
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("cert authentication is only supported on hostssl connections"),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = "cert authentication is only supported on hostssl connections";
    return NULL;
  }

  /*
   * For GSS and SSPI, set the default value of include_realm to true.
   * Having include_realm set to false is dangerous in multi-realm
   * situations and is generally considered bad practice.  We keep the
   * capability around for backwards compatibility, but we might want to
   * remove it at some point in the future.  Users who still need to strip
   * the realm off would be better served by using an appropriate regex in a
   * pg_ident.conf mapping.
   */
  if (parsedline->auth_method == uaGSS ||
    parsedline->auth_method == uaSSPI)
    parsedline->include_realm = true;

  /*
   * For SSPI, include_realm defaults to the SAM-compatible domain (aka
   * NetBIOS name) and user names instead of the Kerberos principal name for
   * compatibility.
   */
  if (parsedline->auth_method == uaSSPI)
  {
    parsedline->compat_realm = true;
    parsedline->upn_username = false;
  }

  /* Parse remaining arguments */
  while ((field = lnext(tok_line->fields, field)) != NULL)
  {
    tokens = lfirst(field);
    foreach(tokencell, tokens)
    {
      char     *val;

      token = lfirst(tokencell);

      str = pstrdup(token->string);
      val = strchr(str, '=');
      if (val == NULL)
      {
        /*
         * Got something that's not a name=value pair.
         */
        ereport(elevel,
            (errcode(ERRCODE_CONFIG_FILE_ERROR),
             errmsg("authentication option not in name=value format: %s", token->string),
             errcontext("line %d of configuration file \"%s\"",
                  line_num, file_name)));
        *err_msg = psprintf("authentication option not in name=value format: %s",
                  token->string);
        return NULL;
      }

      *val++ = '\0';    /* str now holds "name", val holds "value" */
      if (!parse_hba_auth_opt(str, val, parsedline, elevel, err_msg))
        /* parse_hba_auth_opt already logged the error message */
        return NULL;
      pfree(str);
    }
  }

  /*
   * Check if the selected authentication method has any mandatory arguments
   * that are not set.
   */
  if (parsedline->auth_method == uaLDAP)
  {
#ifndef HAVE_LDAP_INITIALIZE
    /* Not mandatory for OpenLDAP, because it can use DNS SRV records */
    MANDATORY_AUTH_ARG(parsedline->ldapserver, "ldapserver", "ldap");
#endif

    /*
     * LDAP can operate in two modes: either with a direct bind, using
     * ldapprefix and ldapsuffix, or using a search+bind, using
     * ldapbasedn, ldapbinddn, ldapbindpasswd and one of
     * ldapsearchattribute or ldapsearchfilter.  Disallow mixing these
     * parameters.
     */
    if (parsedline->ldapprefix || parsedline->ldapsuffix)
    {
      if (parsedline->ldapbasedn ||
        parsedline->ldapbinddn ||
        parsedline->ldapbindpasswd ||
        parsedline->ldapsearchattribute ||
        parsedline->ldapsearchfilter)
      {
        ereport(elevel,
            (errcode(ERRCODE_CONFIG_FILE_ERROR),
             errmsg("cannot mix options for simple bind and search+bind modes"),
             errcontext("line %d of configuration file \"%s\"",
                  line_num, file_name)));
        *err_msg = "cannot mix options for simple bind and search+bind modes";
        return NULL;
      }
    }
    else if (!parsedline->ldapbasedn)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("authentication method \"ldap\" requires argument \"ldapbasedn\", \"ldapprefix\", or \"ldapsuffix\" to be set"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "authentication method \"ldap\" requires argument \"ldapbasedn\", \"ldapprefix\", or \"ldapsuffix\" to be set";
      return NULL;
    }

    /*
     * When using search+bind, you can either use a simple attribute
     * (defaulting to "uid") or a fully custom search filter.  You can't
     * do both.
     */
    if (parsedline->ldapsearchattribute && parsedline->ldapsearchfilter)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("cannot use ldapsearchattribute together with ldapsearchfilter"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "cannot use ldapsearchattribute together with ldapsearchfilter";
      return NULL;
    }
  }

  /*
   * Enforce any parameters implied by other settings.
   */
  if (parsedline->auth_method == uaCert)
  {
    /*
     * For auth method cert, client certificate validation is mandatory,
     * and it implies the level of verify-full.
     */
    parsedline->clientcert = clientCertFull;
  }

  /*
   * Enforce proper configuration of OAuth authentication.
   */
  if (parsedline->auth_method == uaOAuth)
  {
    MANDATORY_AUTH_ARG(parsedline->oauth_scope, "scope", "oauth");
    MANDATORY_AUTH_ARG(parsedline->oauth_issuer, "issuer", "oauth");

    /* Ensure a validator library is set and permitted by the config. */
    if (!check_oauth_validator(parsedline, elevel, err_msg))
      return NULL;

    /*
     * Supplying a usermap combined with the option to skip usermapping is
     * nonsensical and indicates a configuration error.
     */
    if (parsedline->oauth_skip_usermap && parsedline->usermap != NULL)
    {
      ereport(elevel,
          errcode(ERRCODE_CONFIG_FILE_ERROR),
      /* translator: strings are replaced with hba options */
          errmsg("%s cannot be used in combination with %s",
               "map", "delegate_ident_mapping"),
          errcontext("line %d of configuration file \"%s\"",
                 line_num, file_name));
      *err_msg = "map cannot be used in combination with delegate_ident_mapping";
      return NULL;
    }
  }

  return parsedline;
}


/*
 * Parse one name-value pair as an authentication option into the given
 * HbaLine.  Return true if we successfully parse the option, false if we
 * encounter an error.  In the event of an error, also log a message at
 * ereport level elevel, and store a message string into *err_msg.
 */
static bool
parse_hba_auth_opt(char *name, char *val, HbaLine *hbaline,
           int elevel, char **err_msg)
{
  int     line_num = hbaline->linenumber;
  char     *file_name = hbaline->sourcefile;

#ifdef USE_LDAP
  hbaline->ldapscope = LDAP_SCOPE_SUBTREE;
#endif

  if (strcmp(name, "map") == 0)
  {
    if (hbaline->auth_method != uaIdent &&
      hbaline->auth_method != uaPeer &&
      hbaline->auth_method != uaGSS &&
      hbaline->auth_method != uaSSPI &&
      hbaline->auth_method != uaCert &&
      hbaline->auth_method != uaOAuth)
      INVALID_AUTH_OPTION("map", gettext_noop("ident, peer, gssapi, sspi, cert, and oauth"));
    hbaline->usermap = pstrdup(val);
  }
  else if (strcmp(name, "clientcert") == 0)
  {
    if (hbaline->conntype != ctHostSSL)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("clientcert can only be configured for \"hostssl\" rows"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "clientcert can only be configured for \"hostssl\" rows";
      return false;
    }

    if (strcmp(val, "verify-full") == 0)
    {
      hbaline->clientcert = clientCertFull;
    }
    else if (strcmp(val, "verify-ca") == 0)
    {
      if (hbaline->auth_method == uaCert)
      {
        ereport(elevel,
            (errcode(ERRCODE_CONFIG_FILE_ERROR),
             errmsg("clientcert only accepts \"verify-full\" when using \"cert\" authentication"),
             errcontext("line %d of configuration file \"%s\"",
                  line_num, file_name)));
        *err_msg = "clientcert can only be set to \"verify-full\" when using \"cert\" authentication";
        return false;
      }

      hbaline->clientcert = clientCertCA;
    }
    else
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("invalid value for clientcert: \"%s\"", val),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      return false;
    }
  }
  else if (strcmp(name, "clientname") == 0)
  {
    if (hbaline->conntype != ctHostSSL)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("clientname can only be configured for \"hostssl\" rows"),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = "clientname can only be configured for \"hostssl\" rows";
      return false;
    }

    if (strcmp(val, "CN") == 0)
    {
      hbaline->clientcertname = clientCertCN;
    }
    else if (strcmp(val, "DN") == 0)
    {
      hbaline->clientcertname = clientCertDN;
    }
    else
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("invalid value for clientname: \"%s\"", val),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      return false;
    }
  }
  else if (strcmp(name, "pamservice") == 0)
  {
    REQUIRE_AUTH_OPTION(uaPAM, "pamservice", "pam");
    hbaline->pamservice = pstrdup(val);
  }
  else if (strcmp(name, "pam_use_hostname") == 0)
  {
    REQUIRE_AUTH_OPTION(uaPAM, "pam_use_hostname", "pam");
    if (strcmp(val, "1") == 0)
      hbaline->pam_use_hostname = true;
    else
      hbaline->pam_use_hostname = false;
  }
  else if (strcmp(name, "ldapurl") == 0)
  {
#ifdef LDAP_API_FEATURE_X_OPENLDAP
    LDAPURLDesc *urldata;
    int     rc;
#endif

    REQUIRE_AUTH_OPTION(uaLDAP, "ldapurl", "ldap");
#ifdef LDAP_API_FEATURE_X_OPENLDAP
    rc = ldap_url_parse(val, &urldata);
    if (rc != LDAP_SUCCESS)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("could not parse LDAP URL \"%s\": %s", val, ldap_err2string(rc))));
      *err_msg = psprintf("could not parse LDAP URL \"%s\": %s",
                val, ldap_err2string(rc));
      return false;
    }

    if (strcmp(urldata->lud_scheme, "ldap") != 0 &&
      strcmp(urldata->lud_scheme, "ldaps") != 0)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("unsupported LDAP URL scheme: %s", urldata->lud_scheme)));
      *err_msg = psprintf("unsupported LDAP URL scheme: %s",
                urldata->lud_scheme);
      ldap_free_urldesc(urldata);
      return false;
    }

    if (urldata->lud_scheme)
      hbaline->ldapscheme = pstrdup(urldata->lud_scheme);
    if (urldata->lud_host)
      hbaline->ldapserver = pstrdup(urldata->lud_host);
    hbaline->ldapport = urldata->lud_port;
    if (urldata->lud_dn)
      hbaline->ldapbasedn = pstrdup(urldata->lud_dn);

    if (urldata->lud_attrs)
      hbaline->ldapsearchattribute = pstrdup(urldata->lud_attrs[0]);  /* only use first one */
    hbaline->ldapscope = urldata->lud_scope;
    if (urldata->lud_filter)
      hbaline->ldapsearchfilter = pstrdup(urldata->lud_filter);
    ldap_free_urldesc(urldata);
#else             /* not OpenLDAP */
    ereport(elevel,
        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
         errmsg("LDAP URLs not supported on this platform")));
    *err_msg = "LDAP URLs not supported on this platform";
#endif              /* not OpenLDAP */
  }
  else if (strcmp(name, "ldaptls") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldaptls", "ldap");
    if (strcmp(val, "1") == 0)
      hbaline->ldaptls = true;
    else
      hbaline->ldaptls = false;
  }
  else if (strcmp(name, "ldapscheme") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapscheme", "ldap");
    if (strcmp(val, "ldap") != 0 && strcmp(val, "ldaps") != 0)
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("invalid ldapscheme value: \"%s\"", val),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
    hbaline->ldapscheme = pstrdup(val);
  }
  else if (strcmp(name, "ldapserver") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapserver", "ldap");
    hbaline->ldapserver = pstrdup(val);
  }
  else if (strcmp(name, "ldapport") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapport", "ldap");
    hbaline->ldapport = atoi(val);
    if (hbaline->ldapport == 0)
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("invalid LDAP port number: \"%s\"", val),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      *err_msg = psprintf("invalid LDAP port number: \"%s\"", val);
      return false;
    }
  }
  else if (strcmp(name, "ldapbinddn") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapbinddn", "ldap");
    hbaline->ldapbinddn = pstrdup(val);
  }
  else if (strcmp(name, "ldapbindpasswd") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapbindpasswd", "ldap");
    hbaline->ldapbindpasswd = pstrdup(val);
  }
  else if (strcmp(name, "ldapsearchattribute") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapsearchattribute", "ldap");
    hbaline->ldapsearchattribute = pstrdup(val);
  }
  else if (strcmp(name, "ldapsearchfilter") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapsearchfilter", "ldap");
    hbaline->ldapsearchfilter = pstrdup(val);
  }
  else if (strcmp(name, "ldapbasedn") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapbasedn", "ldap");
    hbaline->ldapbasedn = pstrdup(val);
  }
  else if (strcmp(name, "ldapprefix") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapprefix", "ldap");
    hbaline->ldapprefix = pstrdup(val);
  }
  else if (strcmp(name, "ldapsuffix") == 0)
  {
    REQUIRE_AUTH_OPTION(uaLDAP, "ldapsuffix", "ldap");
    hbaline->ldapsuffix = pstrdup(val);
  }
  else if (strcmp(name, "krb_realm") == 0)
  {
    if (hbaline->auth_method != uaGSS &&
      hbaline->auth_method != uaSSPI)
      INVALID_AUTH_OPTION("krb_realm", gettext_noop("gssapi and sspi"));
    hbaline->krb_realm = pstrdup(val);
  }
  else if (strcmp(name, "include_realm") == 0)
  {
    if (hbaline->auth_method != uaGSS &&
      hbaline->auth_method != uaSSPI)
      INVALID_AUTH_OPTION("include_realm", gettext_noop("gssapi and sspi"));
    if (strcmp(val, "1") == 0)
      hbaline->include_realm = true;
    else
      hbaline->include_realm = false;
  }
  else if (strcmp(name, "compat_realm") == 0)
  {
    if (hbaline->auth_method != uaSSPI)
      INVALID_AUTH_OPTION("compat_realm", gettext_noop("sspi"));
    if (strcmp(val, "1") == 0)
      hbaline->compat_realm = true;
    else
      hbaline->compat_realm = false;
  }
  else if (strcmp(name, "upn_username") == 0)
  {
    if (hbaline->auth_method != uaSSPI)
      INVALID_AUTH_OPTION("upn_username", gettext_noop("sspi"));
    if (strcmp(val, "1") == 0)
      hbaline->upn_username = true;
    else
      hbaline->upn_username = false;
  }
  else if (strcmp(name, "issuer") == 0)
  {
    REQUIRE_AUTH_OPTION(uaOAuth, "issuer", "oauth");
    hbaline->oauth_issuer = pstrdup(val);
  }
  else if (strcmp(name, "scope") == 0)
  {
    REQUIRE_AUTH_OPTION(uaOAuth, "scope", "oauth");
    hbaline->oauth_scope = pstrdup(val);
  }
  else if (strcmp(name, "validator") == 0)
  {
    REQUIRE_AUTH_OPTION(uaOAuth, "validator", "oauth");
    hbaline->oauth_validator = pstrdup(val);
  }
  else if (strncmp(name, "validator.", strlen("validator.")) == 0)
  {
    const char *key = name + strlen("validator.");

    REQUIRE_AUTH_OPTION(uaOAuth, name, "oauth");

    /*
     * Validator modules may register their own per-HBA-line options.
     * Unfortunately, since we don't want to require these modules to be
     * loaded into the postmaster, we don't know if the options are valid
     * yet and must store them for later. Perform only a basic syntax
     * check here.
     */
    if (!valid_oauth_hba_option_name(key))
    {
      ereport(elevel,
          (errcode(ERRCODE_CONFIG_FILE_ERROR),
           errmsg("invalid OAuth validator option name: \"%s\"", name),
           errcontext("line %d of configuration file \"%s\"",
                line_num, file_name)));
      return false;
    }

    hbaline->oauth_opt_keys = lappend(hbaline->oauth_opt_keys, pstrdup(key));
    hbaline->oauth_opt_vals = lappend(hbaline->oauth_opt_vals, pstrdup(val));
  }
  else if (strcmp(name, "delegate_ident_mapping") == 0)
  {
    REQUIRE_AUTH_OPTION(uaOAuth, "delegate_ident_mapping", "oauth");
    if (strcmp(val, "1") == 0)
      hbaline->oauth_skip_usermap = true;
    else
      hbaline->oauth_skip_usermap = false;
  }
  else
  {
    ereport(elevel,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("unrecognized authentication option name: \"%s\"",
            name),
         errcontext("line %d of configuration file \"%s\"",
              line_num, file_name)));
    *err_msg = psprintf("unrecognized authentication option name: \"%s\"",
              name);
    return false;
  }
  return true;
}

/*
 *  Scan the pre-parsed hba file, looking for a match to the port's connection
 *  request.
 */
static void
check_hba(Port *port)
{
  Oid     roleid;
  ListCell   *line;
  HbaLine    *hba;

  /* Get the target role's OID.  Note we do not error out for bad role. */
  roleid = get_role_oid(port->user_name, true);

  foreach(line, parsed_hba_lines)
  {
    hba = (HbaLine *) lfirst(line);

    /* Check connection type */
    if (hba->conntype == ctLocal)
    {
      if (port->raddr.addr.ss_family != AF_UNIX)
        continue;
    }
    else
    {
      if (port->raddr.addr.ss_family == AF_UNIX)
        continue;

      /* Check SSL state */
      if (port->ssl_in_use)
      {
        /* Connection is SSL, match both "host" and "hostssl" */
        if (hba->conntype == ctHostNoSSL)
          continue;
      }
      else
      {
        /* Connection is not SSL, match both "host" and "hostnossl" */
        if (hba->conntype == ctHostSSL)
          continue;
      }

      /* Check GSSAPI state */
#ifdef ENABLE_GSS
      if (port->gss && port->gss->enc &&
        hba->conntype == ctHostNoGSS)
        continue;
      else if (!(port->gss && port->gss->enc) &&
           hba->conntype == ctHostGSS)
        continue;
#else
      if (hba->conntype == ctHostGSS)
        continue;
#endif

      /* Check IP address */
      switch (hba->ip_cmp_method)
      {
        case ipCmpMask:
          if (hba->hostname)
          {
            if (!check_hostname(port,
                      hba->hostname))
              continue;
          }
          else
          {
            if (!check_ip(&port->raddr,
                    (struct sockaddr *) &hba->addr,
                    (struct sockaddr *) &hba->mask))
              continue;
          }
          break;
        case ipCmpAll:
          break;
        case ipCmpSameHost:
        case ipCmpSameNet:
          if (!check_same_host_or_net(&port->raddr,
                        hba->ip_cmp_method))
            continue;
          break;
        default:
          /* shouldn't get here, but deem it no-match if so */
          continue;
      }
    }           /* != ctLocal */

    /* Check database and role */
    if (!check_db(port->database_name, port->user_name, roleid,
            hba->databases))
      continue;

    if (!check_role(port->user_name, roleid, hba->roles, false))
      continue;

    /* Found a record that matched! */
    port->hba = hba;
    return;
  }

  /* If no matching entry was found, then implicitly reject. */
  hba = palloc0_object(HbaLine);
  hba->auth_method = uaImplicitReject;
  port->hba = hba;
}

/*
 * Read the config file and create a List of HbaLine records for the contents.
 *
 * The configuration is read into a temporary list, and if any parse error
 * occurs the old list is kept in place and false is returned.  Only if the
 * whole file parses OK is the list replaced, and the function returns true.
 *
 * On a false result, caller will take care of reporting a FATAL error in case
 * this is the initial startup.  If it happens on reload, we just keep running
 * with the old data.
 */
bool
load_hba(void)
{
  FILE     *file;
  List     *hba_lines = NIL;
  ListCell   *line;
  List     *new_parsed_lines = NIL;
  bool    ok = true;
  MemoryContext oldcxt;
  MemoryContext hbacxt;

  file = open_auth_file(HbaFileName, LOG, 0, NULL);
  if (file == NULL)
  {
    /* error already logged */
    return false;
  }

  tokenize_auth_file(HbaFileName, file, &hba_lines, LOG, 0);

  /* Now parse all the lines */
  Assert(PostmasterContext);
  hbacxt = AllocSetContextCreate(PostmasterContext,
                   "hba parser context",
                   ALLOCSET_SMALL_SIZES);
  oldcxt = MemoryContextSwitchTo(hbacxt);
  foreach(line, hba_lines)
  {
    TokenizedAuthLine *tok_line = (TokenizedAuthLine *) lfirst(line);
    HbaLine    *newline;

    /* don't parse lines that already have errors */
    if (tok_line->err_msg != NULL)
    {
      ok = false;
      continue;
    }

    if ((newline = parse_hba_line(tok_line, LOG)) == NULL)
    {
      /* Parse error; remember there's trouble */
      ok = false;

      /*
       * Keep parsing the rest of the file so we can report errors on
       * more than the first line.  Error has already been logged, no
       * need for more chatter here.
       */
      continue;
    }

    new_parsed_lines = lappend(new_parsed_lines, newline);
  }

  /*
   * A valid HBA file must have at least one entry; else there's no way to
   * connect to the postmaster.  But only complain about this if we didn't
   * already have parsing errors.
   */
  if (ok && new_parsed_lines == NIL)
  {
    ereport(LOG,
        (errcode(ERRCODE_CONFIG_FILE_ERROR),
         errmsg("configuration file \"%s\" contains no entries",
            HbaFileName)));
    ok = false;
  }

  /* Free tokenizer memory */
  free_auth_file(file, 0);
  MemoryContextSwitchTo(oldcxt);

  if (!ok)
  {
    /*
     * File contained one or more errors, so bail out. MemoryContextDelete
     * is enough to clean up everything, including regexes.
     */
    MemoryContextDelete(hbacxt);
    return false;
  }

  /* Loaded new file successfully, replace the one we use */
  if (parsed_hba_context != NULL)
    MemoryContextDelete(parsed_hba_context);
  parsed_hba_context = hbacxt;
  parsed_hba_lines = new_parsed_lines;

  return true;
}


/*
 * Parse one tokenised line from the ident config file and store the result in
 * an IdentLine structure.
 *
 * If parsing fails, log a message at ereport level elevel, store an error
 * string in tok_line->err_msg and return NULL.
 *
 * If ident_user is a regular expression (ie. begins with a slash), it is
 * compiled and stored in IdentLine structure.
 *
 * Note: this function leaks memory when an error occurs.  Caller is expected
 * to have set a memory context that will be reset if this function returns
 * NULL.
 */
IdentLine *
parse_ident_line(TokenizedAuthLine *tok_line, int elevel)
{
  int     line_num = tok_line->line_num;
  char     *file_name = tok_line->file_name;
  char    **err_msg = &tok_line->err_msg;
  ListCell   *field;
  List     *tokens;
  AuthToken  *token;
  IdentLine  *parsedline;

  Assert(tok_line->fields != NIL);
  field = list_head(tok_line->fields);

  parsedline = palloc0_object(IdentLine);
  parsedline->linenumber = line_num;

  /* Get the map token (must exist) */
  tokens = lfirst(field);
  IDENT_MULTI_VALUE(tokens);
  token = linitial(tokens);
  parsedline->usermap = pstrdup(token->string);

  /* Get the ident user token */
  field = lnext(tok_line->fields, field);
  IDENT_FIELD_ABSENT(field);
  tokens = lfirst(field);
  IDENT_MULTI_VALUE(tokens);
  token = linitial(tokens);

  /* Copy the ident user token */
  parsedline->system_user = copy_auth_token(token);

  /* Get the PG rolename token */
  field = lnext(tok_line->fields, field);
  IDENT_FIELD_ABSENT(field);
  tokens = lfirst(field);
  IDENT_MULTI_VALUE(tokens);
  token = linitial(tokens);
  parsedline->pg_user = copy_auth_token(token);

  /*
   * Now that the field validation is done, compile a regex from the user
   * tokens, if necessary.
   */
  if (regcomp_auth_token(parsedline->system_user, file_name, line_num,
               err_msg, elevel))
  {
    /* err_msg includes the error to report */
    return NULL;
  }

  if (regcomp_auth_token(parsedline->pg_user, file_name, line_num,
               err_msg, elevel))
  {
    /* err_msg includes the error to report */
    return NULL;
  }

  return parsedline;
}

/*
 *  Process one line from the parsed ident config lines.
 *
 *  Compare input parsed ident line to the needed map, pg_user and system_user.
 *  *found_p and *error_p are set according to our results.
 */
static void
check_ident_usermap(IdentLine *identLine, const char *usermap_name,
          const char *pg_user, const char *system_user,
          bool case_insensitive, bool *found_p, bool *error_p)
{
  Oid     roleid;

  *found_p = false;
  *error_p = false;

  if (strcmp(identLine->usermap, usermap_name) != 0)
    /* Line does not match the map name we're looking for, so just abort */
    return;

  /* Get the target role's OID.  Note we do not error out for bad role. */
  roleid = get_role_oid(pg_user, true);

  /* Match? */
  if (token_has_regexp(identLine->system_user))
  {
    /*
     * Process the system username as a regular expression that returns
     * exactly one match. This is replaced for \1 in the database username
     * string, if present.
     */
    int     r;
    regmatch_t  matches[2];
    char     *ofs;
    AuthToken  *expanded_pg_user_token;
    bool    created_temporary_token = false;

    r = regexec_auth_token(system_user, identLine->system_user, 2, matches);
    if (r)
    {
      char    errstr[100];

      if (r != REG_NOMATCH)
      {
        /* REG_NOMATCH is not an error, everything else is */
        pg_regerror(r, identLine->system_user->regex, errstr, sizeof(errstr));
        ereport(LOG,
            (errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
             errmsg("regular expression match for \"%s\" failed: %s",
                identLine->system_user->string + 1, errstr)));
        *error_p = true;
      }
      return;
    }

    /*
     * Replace \1 with the first captured group unless the field already
     * has some special meaning, like a group membership or a regexp-based
     * check.
     */
    if (!token_is_member_check(identLine->pg_user) &&
      !token_has_regexp(identLine->pg_user) &&
      (ofs = strstr(identLine->pg_user->string, "\\1")) != NULL)
    {
      const char *repl_str;
      size_t    repl_len;
      char     *old_pg_user;
      char     *expanded_pg_user;
      size_t    offset;

      /* substitution of the first argument requested */
      if (matches[1].rm_so < 0)
      {
        ereport(LOG,
            (errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
             errmsg("regular expression \"%s\" has no subexpressions as requested by backreference in \"%s\"",
                identLine->system_user->string + 1, identLine->pg_user->string)));
        *error_p = true;
        return;
      }
      repl_str = system_user + matches[1].rm_so;
      repl_len = matches[1].rm_eo - matches[1].rm_so;

      /*
       * It's allowed to have more than one \1 in the string, and we'll
       * replace them all.  But that's pretty unusual so we optimize on
       * the assumption of only one occurrence, which motivates doing
       * repeated replacements instead of making two passes over the
       * string to determine the final length right away.
       */
      old_pg_user = identLine->pg_user->string;
      do
      {
        /*
         * length: current length minus length of \1 plus length of
         * replacement plus null terminator
         */
        expanded_pg_user = palloc(strlen(old_pg_user) - 2 + repl_len + 1);
        /* ofs points into the old_pg_user string at this point */
        offset = ofs - old_pg_user;
        memcpy(expanded_pg_user, old_pg_user, offset);
        memcpy(expanded_pg_user + offset, repl_str, repl_len);
        strcpy(expanded_pg_user + offset + repl_len, ofs + 2);
        if (old_pg_user != identLine->pg_user->string)
          pfree(old_pg_user);
        old_pg_user = expanded_pg_user;
      } while ((ofs = strstr(old_pg_user + offset + repl_len, "\\1")) != NULL);

      /*
       * Mark the token as quoted, so it will only be compared literally
       * and not for some special meaning, such as "all" or a group
       * membership check.
       */
      expanded_pg_user_token = make_auth_token(expanded_pg_user, true);
      created_temporary_token = true;
      pfree(expanded_pg_user);
    }
    else
    {
      expanded_pg_user_token = identLine->pg_user;
    }

    /* check the Postgres user */
    *found_p = check_role(pg_user, roleid,
                list_make1(expanded_pg_user_token),
                case_insensitive);

    if (created_temporary_token)
      free_auth_token(expanded_pg_user_token);

    return;
  }
  else
  {
    /*
     * Not a regular expression, so make a complete match.  If the system
     * user does not match, just leave.
     */
    if (case_insensitive)
    {
      if (!token_matches_insensitive(identLine->system_user,
                       system_user))
        return;
    }
    else
    {
      if (!token_matches(identLine->system_user, system_user))
        return;
    }

    /* check the Postgres user */
    *found_p = check_role(pg_user, roleid,
                list_make1(identLine->pg_user),
                case_insensitive);
  }
}


/*
 *  Scan the (pre-parsed) ident usermap file line by line, looking for a match
 *
 *  See if the system user with ident username "system_user" is allowed to act as
 *  Postgres user "pg_user" according to usermap "usermap_name".
 *
 *  Special case: Usermap NULL, equivalent to what was previously called
 *  "sameuser" or "samerole", means don't look in the usermap file.
 *  That's an implied map wherein "pg_user" must be identical to
 *  "system_user" in order to be authorized.
 *
 *  Iff authorized, return STATUS_OK, otherwise return STATUS_ERROR.
 */
int
check_usermap(const char *usermap_name,
        const char *pg_user,
        const char *system_user,
        bool case_insensitive)
{
  bool    found_entry = false,
        error = false;

  if (usermap_name == NULL || usermap_name[0] == '\0')
  {
    if (case_insensitive)
    {
      if (pg_strcasecmp(pg_user, system_user) == 0)
        return STATUS_OK;
    }
    else
    {
      if (strcmp(pg_user, system_user) == 0)
        return STATUS_OK;
    }
    ereport(LOG,
        (errmsg("provided user name (%s) and authenticated user name (%s) do not match",
            pg_user, system_user)));
    return STATUS_ERROR;
  }
  else
  {
    ListCell   *line_cell;

    foreach(line_cell, parsed_ident_lines)
    {
      check_ident_usermap(lfirst(line_cell), usermap_name,
                pg_user, system_user, case_insensitive,
                &found_entry, &error);
      if (found_entry || error)
        break;
    }
  }
  if (!found_entry && !error)
  {
    ereport(LOG,
        (errmsg("no match in usermap \"%s\" for user \"%s\" authenticated as \"%s\"",
            usermap_name, pg_user, system_user)));
  }
  return found_entry ? STATUS_OK : STATUS_ERROR;
}


/*
 * Read the ident config file and create a List of IdentLine records for
 * the contents.
 *
 * This works the same as load_hba(), but for the user config file.
 */
bool
load_ident(void)
{
  FILE     *file;
  List     *ident_lines = NIL;
  ListCell   *line_cell;
  List     *new_parsed_lines = NIL;
  bool    ok = true;
  MemoryContext oldcxt;
  MemoryContext ident_context;
  IdentLine  *newline;

  /* not FATAL ... we just won't do any special ident maps */
  file = open_auth_file(IdentFileName, LOG, 0, NULL);
  if (file == NULL)
  {
    /* error already logged */
    return false;
  }

  tokenize_auth_file(IdentFileName, file, &ident_lines, LOG, 0);

  /* Now parse all the lines */
  Assert(PostmasterContext);
  ident_context = AllocSetContextCreate(PostmasterContext,
                      "ident parser context",
                      ALLOCSET_SMALL_SIZES);
  oldcxt = MemoryContextSwitchTo(ident_context);
  foreach(line_cell, ident_lines)
  {
    TokenizedAuthLine *tok_line = (TokenizedAuthLine *) lfirst(line_cell);

    /* don't parse lines that already have errors */
    if (tok_line->err_msg != NULL)
    {
      ok = false;
      continue;
    }

    if ((newline = parse_ident_line(tok_line, LOG)) == NULL)
    {
      /* Parse error; remember there's trouble */
      ok = false;

      /*
       * Keep parsing the rest of the file so we can report errors on
       * more than the first line.  Error has already been logged, no
       * need for more chatter here.
       */
      continue;
    }

    new_parsed_lines = lappend(new_parsed_lines, newline);
  }

  /* Free tokenizer memory */
  free_auth_file(file, 0);
  MemoryContextSwitchTo(oldcxt);

  if (!ok)
  {
    /*
     * File contained one or more errors, so bail out. MemoryContextDelete
     * is enough to clean up everything, including regexes.
     */
    MemoryContextDelete(ident_context);
    return false;
  }

  /* Loaded new file successfully, replace the one we use */
  if (parsed_ident_context != NULL)
    MemoryContextDelete(parsed_ident_context);

  parsed_ident_context = ident_context;
  parsed_ident_lines = new_parsed_lines;

  return true;
}



/*
 *  Determine what authentication method should be used when accessing database
 *  "database" from frontend "raddr", user "user".  Return the method and
 *  an optional argument (stored in fields of *port), and STATUS_OK.
 *
 *  If the file does not contain any entry matching the request, we return
 *  method = uaImplicitReject.
 */
void
hba_getauthmethod(Port *port)
{
  check_hba(port);
}


/*
 * Return the name of the auth method in use ("gss", "md5", "trust", etc.).
 *
 * The return value is statically allocated (see the UserAuthName array) and
 * should not be freed.
 */
const char *
hba_authname(UserAuth auth_method)
{
  return UserAuthName[auth_method];
}

Coverage Report

Created: 2026-08-14 06:37