blob: 513c930286feb89565a2895d40c7e2e9eaa18827
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com> |
4 | * All rights reserved. |
5 | * |
6 | * Redistribution and use in source and binary forms, with or without |
7 | * modification, are permitted provided that the following conditions |
8 | * are met: |
9 | * 1. Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * 2. Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
14 | * 3. Neither the name of Julianne F. Haugh nor the names of its contributors |
15 | * may be used to endorse or promote products derived from this software |
16 | * without specific prior written permission. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND |
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
21 | * ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE |
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
28 | * SUCH DAMAGE. |
29 | */ |
30 | |
31 | #include "libbb.h" |
32 | |
33 | #define SHADOW_BUFSIZE 256 |
34 | |
35 | /* Retrieve encrypted password string for pw. |
36 | * If pw == NULL, return a string which fails password check against any |
37 | * password. |
38 | */ |
39 | #if !ENABLE_FEATURE_SHADOWPASSWDS |
40 | #define get_passwd(pw, buffer) get_passwd(pw) |
41 | #endif |
42 | static const char *get_passwd(const struct passwd *pw, char buffer[SHADOW_BUFSIZE]) |
43 | { |
44 | const char *pass; |
45 | |
46 | if (!pw) |
47 | return "aa"; /* "aa" will never match */ |
48 | |
49 | pass = pw->pw_passwd; |
50 | #if ENABLE_FEATURE_SHADOWPASSWDS |
51 | /* Using _r function to avoid pulling in static buffers */ |
52 | if ((pass[0] == 'x' || pass[0] == '*') && !pass[1]) { |
53 | struct spwd spw; |
54 | int r; |
55 | /* getspnam_r may return 0 yet set result to NULL. |
56 | * At least glibc 2.4 does this. Be extra paranoid here. */ |
57 | struct spwd *result = NULL; |
58 | r = getspnam_r(pw->pw_name, &spw, buffer, SHADOW_BUFSIZE, &result); |
59 | pass = (r || !result) ? "aa" : result->sp_pwdp; |
60 | } |
61 | #endif |
62 | return pass; |
63 | } |
64 | |
65 | /* |
66 | * Return 1 if PW has an empty password. |
67 | * Return 1 if the user gives the correct password for entry PW, |
68 | * 0 if not. |
69 | * NULL pw means "just fake it for login with bad username" |
70 | */ |
71 | int FAST_FUNC check_password(const struct passwd *pw, const char *plaintext) |
72 | { |
73 | IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];) |
74 | char *encrypted; |
75 | const char *pw_pass; |
76 | int r; |
77 | |
78 | pw_pass = get_passwd(pw, buffer); |
79 | if (!pw_pass[0]) { /* empty password field? */ |
80 | return 1; |
81 | } |
82 | |
83 | encrypted = pw_encrypt(plaintext, /*salt:*/ pw_pass, 1); |
84 | r = (strcmp(encrypted, pw_pass) == 0); |
85 | free(encrypted); |
86 | return r; |
87 | } |
88 | |
89 | |
90 | /* Ask the user for a password. |
91 | * Return 1 without asking if PW has an empty password. |
92 | * Return -1 on EOF, error while reading input, or timeout. |
93 | * Return 1 if the user gives the correct password for entry PW, |
94 | * 0 if not. |
95 | * |
96 | * NULL pw means "just fake it for login with bad username" |
97 | */ |
98 | int FAST_FUNC ask_and_check_password_extended(const struct passwd *pw, |
99 | int timeout, const char *prompt) |
100 | { |
101 | IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];) |
102 | char *plaintext; |
103 | const char *pw_pass; |
104 | int r; |
105 | |
106 | pw_pass = get_passwd(pw, buffer); |
107 | if (!pw_pass[0]) /* empty password field? */ |
108 | return 1; |
109 | |
110 | plaintext = bb_ask(STDIN_FILENO, timeout, prompt); |
111 | if (!plaintext) { |
112 | /* EOF (such as ^D) or error (such as ^C) or timeout */ |
113 | return -1; |
114 | } |
115 | |
116 | r = check_password(pw, plaintext); |
117 | nuke_str(plaintext); |
118 | return r; |
119 | } |
120 | |
121 | int FAST_FUNC ask_and_check_password(const struct passwd *pw) |
122 | { |
123 | return ask_and_check_password_extended(pw, 0, "Password: "); |
124 | } |
125 |