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Diffstat (limited to '')
| -rw-r--r-- | lib/pwauth.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/lib/pwauth.c b/lib/pwauth.c new file mode 100644 index 0000000..62de472 --- /dev/null +++ b/lib/pwauth.c @@ -0,0 +1,211 @@ +/* + * SPDX-FileCopyrightText: 1992 - 1994, Julianne Frances Haugh + * SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz + * SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko + * SPDX-FileCopyrightText: 2008 - 2009, Nicolas François + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <config.h> + +#ifndef USE_PAM +#ident "$Id$" + +#include <errno.h> +#include <fcntl.h> +#include <signal.h> +#include <stdio.h> +#include <sys/types.h> +#include <unistd.h> +#include "prototypes.h" +#include "defines.h" +#include "pwauth.h" +#include "getdef.h" +#ifdef SKEY +#include <skey.h> +#endif +#ifdef __linux__ /* standard password prompt by default */ +static const char *PROMPT = gettext_noop ("Password: "); +#else +static const char *PROMPT = gettext_noop ("%s's Password: "); +#endif + +bool wipe_clear_pass = true; +/*@null@*/char *clear_pass = NULL; + +/* + * pw_auth - perform getpass/crypt authentication + * + * pw_auth gets the user's cleartext password and encrypts it + * using the salt in the encrypted password. The results are + * compared. + */ + +int pw_auth (const char *cipher, + const char *user, + int reason, + /*@null@*/const char *input) +{ + char prompt[1024]; + char *clear = NULL; + const char *cp; + const char *encrypted; + int retval; + +#ifdef SKEY + bool use_skey = false; + char challenge_info[40]; + struct skey skey; +#endif + + /* + * There are programs for adding and deleting authentication data. + */ + + if ((PW_ADD == reason) || (PW_DELETE == reason)) { + return 0; + } + + /* + * There are even programs for changing the user name ... + */ + + if ((PW_CHANGE == reason) && (NULL != input)) { + return 0; + } + + /* + * WARNING: + * + * When we change a password and we are root, we don't prompt. + * This is so root can change any password without having to + * know it. This is a policy decision that might have to be + * revisited. + */ + + if ((PW_CHANGE == reason) && (getuid () == 0)) { + return 0; + } + + /* + * WARNING: + * + * When we are logging in a user with no ciphertext password, + * we don't prompt for the password or anything. In reality + * the user could just hit <ENTER>, so it doesn't really + * matter. + */ + + if ((NULL == cipher) || ('\0' == *cipher)) { + return 0; + } + +#ifdef SKEY + /* + * If the user has an S/KEY entry show them the pertinent info + * and then we can try validating the created ciphertext and the SKEY. + * If there is no SKEY information we default to not using SKEY. + */ + +# ifdef SKEY_BSD_STYLE + /* + * Some BSD updates to the S/KEY API adds a fourth parameter; the + * sizeof of the challenge info buffer. + */ +# define skeychallenge(s,u,c) skeychallenge(s,u,c,sizeof(c)) +# endif + + if (skeychallenge (&skey, user, challenge_info) == 0) { + use_skey = true; + } +#endif + + /* + * Prompt for the password as required. FTPD and REXECD both + * get the cleartext password for us. + */ + + if ((PW_FTP != reason) && (PW_REXEC != reason) && (NULL == input)) { + cp = getdef_str ("LOGIN_STRING"); + if (NULL == cp) { + cp = _(PROMPT); + } +#ifdef SKEY + if (use_skey) { + printf ("[%s]\n", challenge_info); + } +#endif + + snprintf (prompt, sizeof prompt, cp, user); + clear = getpass (prompt); + if (NULL == clear) { + static char c[1]; + + c[0] = '\0'; + clear = c; + } + input = clear; + } + + /* + * Convert the cleartext password into a ciphertext string. + * If the two match, the return value will be zero, which is + * SUCCESS. Otherwise we see if SKEY is being used and check + * the results there as well. + */ + + encrypted = pw_encrypt (input, cipher); + if (NULL != encrypted) { + retval = strcmp (encrypted, cipher); + } else { + retval = -1; + } + +#ifdef SKEY + /* + * If (1) The password fails to match, and + * (2) The password is empty and + * (3) We are using OPIE or S/Key, then + * ...Re-prompt, with echo on. + * -- AR 8/22/1999 + */ + if ((0 != retval) && ('\0' == input[0]) && use_skey) { + clear = getpass (prompt); + if (NULL == clear) { + static char c[1]; + + c[0] = '\0'; + clear = c; + } + input = clear; + } + + if ((0 != retval) && use_skey) { + int passcheck = -1; + + if (skeyverify (&skey, input) == 0) { + passcheck = skey.n; + } + if (passcheck > 0) { + retval = 0; + } + } +#endif + + /* + * Things like RADIUS authentication may need the password - + * if the external variable wipe_clear_pass is zero, we will + * not wipe it (the caller should wipe clear_pass when it is + * no longer needed). --marekm + */ + + clear_pass = clear; + if (wipe_clear_pass && (NULL != clear) && ('\0' != *clear)) { + strzero (clear); + } + return retval; +} +#else /* !USE_PAM */ +extern int errno; /* warning: ANSI C forbids an empty source file */ +#endif /* !USE_PAM */ |