postgres/src/bin/scripts/dropuser.c
Tom Lane 67a472d71c Remove arbitrary restrictions on password length.
This patch started out with the goal of harmonizing various arbitrary
limits on password length, but after awhile a better idea emerged:
let's just get rid of those fixed limits.

recv_password_packet() has an arbitrary limit on the packet size,
which we don't really need, so just drop it.  (Note that this doesn't
really affect anything for MD5 or SCRAM password verification, since
those will hash the user's password to something shorter anyway.
It does matter for auth methods that require a cleartext password.)

Likewise remove the arbitrary error condition in pg_saslprep().

The remaining limits are mostly in client-side code that prompts
for passwords.  To improve those, refactor simple_prompt() so that
it allocates its own result buffer that can be made as big as
necessary.  Actually, it proves best to make a separate routine
pg_get_line() that has essentially the semantics of fgets(), except
that it allocates a suitable result buffer and hence will never
return a truncated line.  (pg_get_line has a lot of potential
applications to replace randomly-sized fgets buffers elsewhere,
but I'll leave that for another patch.)

I built pg_get_line() atop stringinfo.c, which requires moving
that code to src/common/; but that seems fine since it was a poor
fit for src/port/ anyway.

This patch is mostly mine, but it owes a good deal to Nathan Bossart
who pressed for a solution to the password length problem and
created a predecessor patch.  Also thanks to Peter Eisentraut and
Stephen Frost for ideas and discussion.

Discussion: https://postgr.es/m/09512C4F-8CB9-4021-B455-EF4C4F0D55A0@amazon.com
2020-09-03 20:09:18 -04:00

179 lines
4.5 KiB
C

/*-------------------------------------------------------------------------
*
* dropuser
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/bin/scripts/dropuser.c
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include "common.h"
#include "common/logging.h"
#include "common/string.h"
#include "fe_utils/string_utils.h"
static void help(const char *progname);
int
main(int argc, char *argv[])
{
static int if_exists = 0;
static struct option long_options[] = {
{"host", required_argument, NULL, 'h'},
{"port", required_argument, NULL, 'p'},
{"username", required_argument, NULL, 'U'},
{"no-password", no_argument, NULL, 'w'},
{"password", no_argument, NULL, 'W'},
{"echo", no_argument, NULL, 'e'},
{"interactive", no_argument, NULL, 'i'},
{"if-exists", no_argument, &if_exists, 1},
{NULL, 0, NULL, 0}
};
const char *progname;
int optindex;
int c;
char *dropuser = NULL;
char *host = NULL;
char *port = NULL;
char *username = NULL;
enum trivalue prompt_password = TRI_DEFAULT;
bool echo = false;
bool interactive = false;
PQExpBufferData sql;
PGconn *conn;
PGresult *result;
pg_logging_init(argv[0]);
progname = get_progname(argv[0]);
set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pgscripts"));
handle_help_version_opts(argc, argv, "dropuser", help);
while ((c = getopt_long(argc, argv, "h:p:U:wWei", long_options, &optindex)) != -1)
{
switch (c)
{
case 'h':
host = pg_strdup(optarg);
break;
case 'p':
port = pg_strdup(optarg);
break;
case 'U':
username = pg_strdup(optarg);
break;
case 'w':
prompt_password = TRI_NO;
break;
case 'W':
prompt_password = TRI_YES;
break;
case 'e':
echo = true;
break;
case 'i':
interactive = true;
break;
case 0:
/* this covers the long options */
break;
default:
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
switch (argc - optind)
{
case 0:
break;
case 1:
dropuser = argv[optind];
break;
default:
pg_log_error("too many command-line arguments (first is \"%s\")",
argv[optind + 1]);
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (dropuser == NULL)
{
if (interactive)
{
dropuser = simple_prompt("Enter name of role to drop: ", true);
}
else
{
pg_log_error("missing required argument role name");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
if (interactive)
{
printf(_("Role \"%s\" will be permanently removed.\n"), dropuser);
if (!yesno_prompt("Are you sure?"))
exit(0);
}
initPQExpBuffer(&sql);
appendPQExpBuffer(&sql, "DROP ROLE %s%s;",
(if_exists ? "IF EXISTS " : ""), fmtId(dropuser));
conn = connectDatabase("postgres", host, port, username, prompt_password,
progname, echo, false, false);
if (echo)
printf("%s\n", sql.data);
result = PQexec(conn, sql.data);
if (PQresultStatus(result) != PGRES_COMMAND_OK)
{
pg_log_error("removal of role \"%s\" failed: %s",
dropuser, PQerrorMessage(conn));
PQfinish(conn);
exit(1);
}
PQclear(result);
PQfinish(conn);
exit(0);
}
static void
help(const char *progname)
{
printf(_("%s removes a PostgreSQL role.\n\n"), progname);
printf(_("Usage:\n"));
printf(_(" %s [OPTION]... [ROLENAME]\n"), progname);
printf(_("\nOptions:\n"));
printf(_(" -e, --echo show the commands being sent to the server\n"));
printf(_(" -i, --interactive prompt before deleting anything, and prompt for\n"
" role name if not specified\n"));
printf(_(" -V, --version output version information, then exit\n"));
printf(_(" --if-exists don't report error if user doesn't exist\n"));
printf(_(" -?, --help show this help, then exit\n"));
printf(_("\nConnection options:\n"));
printf(_(" -h, --host=HOSTNAME database server host or socket directory\n"));
printf(_(" -p, --port=PORT database server port\n"));
printf(_(" -U, --username=USERNAME user name to connect as (not the one to drop)\n"));
printf(_(" -w, --no-password never prompt for password\n"));
printf(_(" -W, --password force password prompt\n"));
printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}