pam_get_authtok.c revision 95908
1/*- 2 * Copyright (c) 2002 Networks Associates Technology, Inc. 3 * All rights reserved. 4 * 5 * This software was developed for the FreeBSD Project by ThinkSec AS and 6 * NAI Labs, the Security Research Division of Network Associates, Inc. 7 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 8 * DARPA CHATS research program. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote 19 * products derived from this software without specific prior written 20 * permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $P4: //depot/projects/openpam/lib/pam_get_authtok.c#17 $ 35 */ 36 37#include <sys/param.h> 38 39#include <stdlib.h> 40 41#include <security/pam_appl.h> 42#include <security/openpam.h> 43 44#include "openpam_impl.h" 45 46const char authtok_prompt[] = "Password:"; 47const char oldauthtok_prompt[] = "Old Password:"; 48const char newauthtok_prompt[] = "New Password:"; 49 50/* 51 * OpenPAM extension 52 * 53 * Retrieve authentication token 54 */ 55 56int 57pam_get_authtok(pam_handle_t *pamh, 58 int item, 59 const char **authtok, 60 const char *prompt) 61{ 62 const void *oldauthtok; 63 const char *default_prompt; 64 char *resp, *resp2; 65 int pitem, r, style, twice; 66 67 if (pamh == NULL || authtok == NULL) 68 return (PAM_SYSTEM_ERR); 69 70 *authtok = NULL; 71 twice = 0; 72 switch (item) { 73 case PAM_AUTHTOK: 74 pitem = PAM_AUTHTOK_PROMPT; 75 default_prompt = authtok_prompt; 76 r = pam_get_item(pamh, PAM_OLDAUTHTOK, &oldauthtok); 77 if (r == PAM_SUCCESS && oldauthtok != NULL) { 78 default_prompt = newauthtok_prompt; 79 twice = 1; 80 } 81 break; 82 case PAM_OLDAUTHTOK: 83 pitem = PAM_OLDAUTHTOK_PROMPT; 84 default_prompt = oldauthtok_prompt; 85 twice = 0; 86 break; 87 default: 88 return (PAM_SYMBOL_ERR); 89 } 90 91 if (openpam_get_option(pamh, "try_first_pass") || 92 openpam_get_option(pamh, "use_first_pass")) { 93 r = pam_get_item(pamh, item, (const void **)authtok); 94 if (r == PAM_SUCCESS && *authtok != NULL) 95 return (PAM_SUCCESS); 96 else if (openpam_get_option(pamh, "use_first_pass")) 97 return (r == PAM_SUCCESS ? PAM_AUTH_ERR : r); 98 } 99 if (prompt == NULL) { 100 r = pam_get_item(pamh, pitem, (const void **)&prompt); 101 if (r != PAM_SUCCESS || prompt == NULL) 102 prompt = default_prompt; 103 } 104 style = openpam_get_option(pamh, "echo_pass") ? 105 PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF; 106 r = pam_prompt(pamh, style, &resp, "%s", prompt); 107 if (r != PAM_SUCCESS) 108 return (r); 109 if (twice) { 110 r = pam_prompt(pamh, style, &resp2, "Retype %s", prompt); 111 if (r != PAM_SUCCESS) { 112 free(resp); 113 return (r); 114 } 115 if (strcmp(resp, resp2) != 0) { 116 free(resp); 117 resp = NULL; 118 } 119 free(resp2); 120 } 121 if (resp == NULL) 122 return (PAM_TRY_AGAIN); 123 r = pam_set_item(pamh, item, resp); 124 free(resp); 125 if (r != PAM_SUCCESS) 126 return (r); 127 return (pam_get_item(pamh, item, (const void **)authtok)); 128} 129 130/* 131 * Error codes: 132 * 133 * =pam_get_item 134 * =pam_prompt 135 * =pam_set_item 136 * !PAM_SYMBOL_ERR 137 * PAM_TRY_AGAIN 138 */ 139 140/** 141 * The =pam_get_authtok function returns the cached authentication token, 142 * or prompts the user if no token is currently cached. Either way, a 143 * pointer to the authentication token is stored in the location pointed 144 * to by the =authtok argument. 145 * 146 * The =item argument must have one of the following values: 147 * 148 * =PAM_AUTHTOK: 149 * Returns the current authentication token, or the new token 150 * when changing authentication tokens. 151 * =PAM_OLDAUTHTOK: 152 * Returns the previous authentication token when changing 153 * authentication tokens. 154 * 155 * The =prompt argument specifies a prompt to use if no token is cached. 156 * If it is =NULL, the =PAM_AUTHTOK_PROMPT or =PAM_OLDAUTHTOK_PROMPT item, 157 * as appropriate, will be used. If that item is also =NULL, a hardcoded 158 * default prompt will be used. 159 * 160 * If =item is set to =PAM_AUTHTOK and there is a non-null =PAM_OLDAUTHTOK 161 * item, =pam_get_authtok will ask the user to confirm the new token by 162 * retyping it. If there is a mismatch, =pam_get_authtok will return 163 * =PAM_TRY_AGAIN. 164 * 165 * >pam_get_item 166 * >pam_get_user 167 */ 168