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 36 #ifdef HAVE_CONFIG_H 37 # include "config.h" 38 #endif 39 40 #include <sys/param.h> 41 42 #include <stdlib.h> 43 44 #include <security/pam_appl.h> 45 #include <security/openpam.h> 46 47 #include "openpam_impl.h" 48 49 static const char user_prompt[] = "Login:"; 50 51 /* 52 * XSSO 4.2.1 53 * XSSO 6 page 52 54 * 55 * Retrieve user name 56 */ 57 58 int 59 pam_get_user(pam_handle_t *pamh, 60 const char **user, 61 const char *prompt) 62 { 63 char prompt_buf[1024]; 64 size_t prompt_size; 65 const void *promptp; 66 char *resp; 67 int r; 68 69 ENTER(); 70 r = pam_get_item(pamh, PAM_USER, (const void **)user); 71 if (r == PAM_SUCCESS && *user != NULL) 72 RETURNC(PAM_SUCCESS); 73 /* pam policy overrides the module's choice */ 74 if ((promptp = openpam_get_option(pamh, "user_prompt")) != NULL) 75 prompt = promptp; 76 /* no prompt provided, see if there is one tucked away somewhere */ 77 if (prompt == NULL) { 78 r = pam_get_item(pamh, PAM_USER_PROMPT, &promptp); 79 if (r == PAM_SUCCESS && promptp != NULL) 80 prompt = promptp; 81 } 82 /* fall back to hardcoded default */ 83 if (prompt == NULL) 84 prompt = user_prompt; 85 /* expand */ 86 prompt_size = sizeof prompt_buf; 87 r = openpam_subst(pamh, prompt_buf, &prompt_size, prompt); 88 if (r == PAM_SUCCESS && prompt_size <= sizeof prompt_buf) 89 prompt = prompt_buf; 90 r = pam_prompt(pamh, PAM_PROMPT_ECHO_ON, &resp, "%s", prompt); 91 if (r != PAM_SUCCESS) 92 RETURNC(r); 93 r = pam_set_item(pamh, PAM_USER, resp); 94 FREE(resp); 95 if (r != PAM_SUCCESS) 96 RETURNC(r); 97 r = pam_get_item(pamh, PAM_USER, (const void **)user); 98 RETURNC(r); 99 } 100 101 /* 102 * Error codes: 103 * 104 * =pam_get_item 105 * =pam_prompt 106 * =pam_set_item 107 * !PAM_SYMBOL_ERR 108 */ 109 110 /** 111 * The =pam_get_user function returns the name of the target user, as 112 * specified to =pam_start. 113 * If no user was specified, nor set using =pam_set_item, =pam_get_user 114 * will prompt for a user name. 115 * Either way, a pointer to the user name is stored in the location 116 * pointed to by the =user argument, and the corresponding PAM item is 117 * updated. 118 * 119 * The =prompt argument specifies a prompt to use if no user name is 120 * cached. 121 * If it is =NULL, the =PAM_USER_PROMPT item will be used. 122 * If that item is also =NULL, a hardcoded default prompt will be used. 123 * Additionally, when =pam_get_user is called from a service module, the 124 * prompt may be affected by module options as described below. 125 * The prompt is then expanded using =openpam_subst before it is passed to 126 * the conversation function. 127 * 128 * MODULE OPTIONS 129 * 130 * When called by a service module, =pam_get_user will recognize the 131 * following module options: 132 * 133 * ;user_prompt: 134 * Prompt to use when asking for the user name. 135 * This option overrides both the =prompt argument and the 136 * =PAM_USER_PROMPT item. 137 * 138 * >pam_conv 139 * >pam_get_item 140 * >pam_get_authtok 141 * >openpam_get_option 142 * >openpam_subst 143 */ 144