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/*-------------------------------------------------------------------------
*
* crypt.c
* Look into the password file and check the encrypted password with
* the one passed in from the frontend.
*
* Original coding by Todd A. Brandys
*
* Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/backend/libpq/crypt.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <unistd.h>
#ifdef HAVE_CRYPT_H
#include <crypt.h>
#endif
#include "catalog/pg_authid.h"
#include "libpq/crypt.h"
#include "libpq/md5.h"
#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"
/*
* Check given password for given user, and return STATUS_OK or STATUS_ERROR.
* In the error case, optionally store a palloc'd string at *logdetail
* that will be sent to the postmaster log (but not the client).
*/
int
md5_crypt_verify(const Port *port, const char *role, char *client_pass,
char **logdetail)
{
int retval = STATUS_ERROR;
char *shadow_pass,
*crypt_pwd;
TimestampTz vuntil = 0;
char *crypt_client_pass = client_pass;
HeapTuple roleTup;
Datum datum;
bool isnull;
/*
* Disable immediate interrupts while doing database access. (Note we
* don't bother to turn this back on if we hit one of the failure
* conditions, since we can expect we'll just exit right away anyway.)
*/
ImmediateInterruptOK = false;
/* Get role info from pg_authid */
roleTup = SearchSysCache1(AUTHNAME, PointerGetDatum(role));
if (!HeapTupleIsValid(roleTup))
return STATUS_ERROR; /* no such user */
datum = SysCacheGetAttr(AUTHNAME, roleTup,
Anum_pg_authid_rolpassword, &isnull);
if (isnull)
{
ReleaseSysCache(roleTup);
*logdetail = psprintf(_("User \"%s\" has no password assigned."),
role);
return STATUS_ERROR; /* user has no password */
}
shadow_pass = TextDatumGetCString(datum);
datum = SysCacheGetAttr(AUTHNAME, roleTup,
Anum_pg_authid_rolvaliduntil, &isnull);
if (!isnull)
vuntil = DatumGetTimestampTz(datum);
ReleaseSysCache(roleTup);
/* Re-enable immediate response to SIGTERM/SIGINT/timeout interrupts */
ImmediateInterruptOK = true;
/* And don't forget to detect one that already arrived */
CHECK_FOR_INTERRUPTS();
/*
* Don't allow an empty password. Libpq treats an empty password the same
* as no password at all, and won't even try to authenticate. But other
* clients might, so allowing it would be confusing.
*
* For a plaintext password, we can simply check that it's not an empty
* string. For an encrypted password, check that it does not match the MD5
* hash of an empty string.
*/
if (*shadow_pass == '\0')
{
*logdetail = psprintf(_("User \"%s\" has an empty password."),
role);
return STATUS_ERROR; /* empty password */
}
if (isMD5(shadow_pass))
{
char crypt_empty[MD5_PASSWD_LEN + 1];
if (!pg_md5_encrypt("",
port->user_name,
strlen(port->user_name),
crypt_empty))
return STATUS_ERROR;
if (strcmp(shadow_pass, crypt_empty) == 0)
{
*logdetail = psprintf(_("User \"%s\" has an empty password."),
role);
return STATUS_ERROR; /* empty password */
}
}
/*
* Compare with the encrypted or plain password depending on the
* authentication method being used for this connection.
*/
switch (port->hba->auth_method)
{
case uaMD5:
crypt_pwd = palloc(MD5_PASSWD_LEN + 1);
if (isMD5(shadow_pass))
{
/* stored password already encrypted, only do salt */
if (!pg_md5_encrypt(shadow_pass + strlen("md5"),
port->md5Salt,
sizeof(port->md5Salt), crypt_pwd))
{
pfree(crypt_pwd);
return STATUS_ERROR;
}
}
else
{
/* stored password is plain, double-encrypt */
char *crypt_pwd2 = palloc(MD5_PASSWD_LEN + 1);
if (!pg_md5_encrypt(shadow_pass,
port->user_name,
strlen(port->user_name),
crypt_pwd2))
{
pfree(crypt_pwd);
pfree(crypt_pwd2);
return STATUS_ERROR;
}
if (!pg_md5_encrypt(crypt_pwd2 + strlen("md5"),
port->md5Salt,
sizeof(port->md5Salt),
crypt_pwd))
{
pfree(crypt_pwd);
pfree(crypt_pwd2);
return STATUS_ERROR;
}
pfree(crypt_pwd2);
}
break;
default:
if (isMD5(shadow_pass))
{
/* Encrypt user-supplied password to match stored MD5 */
crypt_client_pass = palloc(MD5_PASSWD_LEN + 1);
if (!pg_md5_encrypt(client_pass,
port->user_name,
strlen(port->user_name),
crypt_client_pass))
{
pfree(crypt_client_pass);
return STATUS_ERROR;
}
}
crypt_pwd = shadow_pass;
break;
}
if (strcmp(crypt_client_pass, crypt_pwd) == 0)
{
/*
* Password OK, now check to be sure we are not past rolvaliduntil
*/
if (isnull)
retval = STATUS_OK;
else if (vuntil < GetCurrentTimestamp())
{
*logdetail = psprintf(_("User \"%s\" has an expired password."),
role);
retval = STATUS_ERROR;
}
else
retval = STATUS_OK;
}
if (port->hba->auth_method == uaMD5)
pfree(crypt_pwd);
if (crypt_client_pass != client_pass)
pfree(crypt_client_pass);
return retval;
}
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