1 /*- 2 * Copyright (c) 2002-2003 Networks Associates Technology, Inc. 3 * Copyright (c) 2004-2017 Dag-Erling Smørgrav 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by ThinkSec AS and 7 * Network Associates Laboratories, the Security Research Division of 8 * Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 9 * ("CBOSS"), as part of the DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The name of the author may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $Id: pam_get_user.c 913 2017-01-21 15:11:12Z des $ 36 */ 37 38 #ifdef HAVE_CONFIG_H 39 # include "config.h" 40 #endif 41 42 #include <sys/param.h> 43 44 #include <stdlib.h> 45 46 #include <security/pam_appl.h> 47 #include <security/openpam.h> 48 49 #include "openpam_impl.h" 50 51 static const char user_prompt[] = "Login:"; 52 53 /* 54 * XSSO 4.2.1 55 * XSSO 6 page 52 56 * 57 * Retrieve user name 58 */ 59 60 int 61 pam_get_user(pam_handle_t *pamh, 62 const char **user, 63 const char *prompt) 64 { 65 char prompt_buf[1024]; 66 size_t prompt_size; 67 const void *promptp; 68 char *resp; 69 int r; 70 71 ENTER(); 72 r = pam_get_item(pamh, PAM_USER, (const void **)user); 73 if (r == PAM_SUCCESS && *user != NULL) 74 RETURNC(PAM_SUCCESS); 75 /* pam policy overrides the module's choice */ 76 if ((promptp = openpam_get_option(pamh, "user_prompt")) != NULL) 77 prompt = promptp; 78 /* no prompt provided, see if there is one tucked away somewhere */ 79 if (prompt == NULL) { 80 r = pam_get_item(pamh, PAM_USER_PROMPT, &promptp); 81 if (r == PAM_SUCCESS && promptp != NULL) 82 prompt = promptp; 83 } 84 /* fall back to hardcoded default */ 85 if (prompt == NULL) 86 prompt = user_prompt; 87 /* expand */ 88 prompt_size = sizeof prompt_buf; 89 r = openpam_subst(pamh, prompt_buf, &prompt_size, prompt); 90 if (r == PAM_SUCCESS && prompt_size <= sizeof prompt_buf) 91 prompt = prompt_buf; 92 r = pam_prompt(pamh, PAM_PROMPT_ECHO_ON, &resp, "%s", prompt); 93 if (r != PAM_SUCCESS) 94 RETURNC(r); 95 r = pam_set_item(pamh, PAM_USER, resp); 96 FREE(resp); 97 if (r != PAM_SUCCESS) 98 RETURNC(r); 99 r = pam_get_item(pamh, PAM_USER, (const void **)user); 100 RETURNC(r); 101 } 102 103 /* 104 * Error codes: 105 * 106 * =pam_get_item 107 * =pam_prompt 108 * =pam_set_item 109 * !PAM_SYMBOL_ERR 110 */ 111 112 /** 113 * The =pam_get_user function returns the name of the target user, as 114 * specified to =pam_start. 115 * If no user was specified, nor set using =pam_set_item, =pam_get_user 116 * will prompt for a user name. 117 * Either way, a pointer to the user name is stored in the location 118 * pointed to by the =user argument, and the corresponding PAM item is 119 * updated. 120 * 121 * The =prompt argument specifies a prompt to use if no user name is 122 * cached. 123 * If it is =NULL, the =PAM_USER_PROMPT item will be used. 124 * If that item is also =NULL, a hardcoded default prompt will be used. 125 * Additionally, when =pam_get_user is called from a service module, the 126 * prompt may be affected by module options as described below. 127 * The prompt is then expanded using =openpam_subst before it is passed to 128 * the conversation function. 129 * 130 * MODULE OPTIONS 131 * 132 * When called by a service module, =pam_get_user will recognize the 133 * following module options: 134 * 135 * ;user_prompt: 136 * Prompt to use when asking for the user name. 137 * This option overrides both the =prompt argument and the 138 * =PAM_USER_PROMPT item. 139 * 140 * >pam_conv 141 * >pam_get_item 142 * >pam_get_authtok 143 * >openpam_get_option 144 * >openpam_subst 145 */ 146