source: squid-ssl/trunk/fuentes/helpers/digest_auth/file/text_backend.cc @ 5495

Last change on this file since 5495 was 5495, checked in by Juanma, 2 years ago

Initial release

File size: 5.9 KB
Line 
1/*
2 * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
3 *
4 * Squid software is distributed under GPLv2+ license and includes
5 * contributions from numerous individuals and organizations.
6 * Please see the COPYING and CONTRIBUTORS files for details.
7 */
8
9/*
10 * AUTHOR: Robert Collins.
11 *  Based on ncsa_auth.c by Arjan de Vet <Arjan.deVet@adv.iae.nl>
12 *
13 * Example digest auth text backend for Squid, based on the original
14 * proxy_auth code from client_side.c, written by
15 * Jon Thackray <jrmt@uk.gdscorp.com>.
16 *
17 * - comment lines are possible and should start with a '#';
18 * - empty or blank lines are possible;
19 * - file format is username:plaintext or username:realm:HA1
20 *
21 * To build a directory integrated backend, you need to be able to
22 * calculate the HA1 returned to squid. To avoid storing a plaintext
23 * password you can calculate MD5(username:realm:password) when the
24 * user changes their password, and store the tuple username:realm:HA1.
25 * then find the matching username:realm when squid asks for the
26 * HA1.
27 *
28 * This implementation could be improved by using such a triple for
29 * the file format.  However storing such a triple does little to
30 * improve security: If compromised the username:realm:HA1 combination
31 * is "plaintext equivalent" - for the purposes of digest authentication
32 * they allow the user access. Password syncronisation is not tackled
33 * by digest - just preventing on the wire compromise.
34 *
35 * Copyright (c) 2003  Robert Collins  <robertc@squid-cache.org>
36 */
37
38#include "squid.h"
39#include "text_backend.h"
40
41static hash_table *hash = NULL;
42static HASHFREE my_free;
43static char *passwdfile = NULL;
44static int ha1mode = 0;
45static time_t change_time = 0;
46
47typedef struct _user_data {
48    hash_link hash;
49    char *passwd;
50    char *ha1;
51} user_data;
52
53static void
54my_free(void *p)
55{
56    user_data *u = static_cast<user_data*>(p);
57    xfree(u->hash.key);
58    xfree(u->passwd);
59    xfree(u);
60}
61
62static void
63read_passwd_file(const char *passwordFile, int isHa1Mode)
64{
65    char buf[8192];
66    user_data *u;
67    char *user;
68    char *passwd;
69    char *ha1 = NULL;
70    char *realm;
71
72    if (hash != NULL) {
73        hashFreeItems(hash, my_free);
74    }
75    /* initial setup */
76    hash = hash_create((HASHCMP *) strcmp, 7921, hash_string);
77    if (NULL == hash) {
78        fprintf(stderr, "digest_file_auth: cannot create hash table\n");
79        exit(1);
80    }
81    FILE *f = fopen(passwordFile, "r");
82    if (!f) {
83        fprintf(stderr, "digest_file_auth: cannot open password file: %s\n", xstrerror());
84        exit(1);
85    }
86    unsigned int lineCount = 0;
87    while (fgets(buf, sizeof(buf), f) != NULL) {
88        ++lineCount;
89        if ((buf[0] == '#') || (buf[0] == ' ') || (buf[0] == '\t') ||
90                (buf[0] == '\n'))
91            continue;
92        user = strtok(buf, ":\n");
93        if (!user) {
94            fprintf(stderr, "digest_file_auth: missing user name at line %u in '%s'\n", lineCount, passwordFile);
95            continue;
96        }
97        realm = strtok(NULL, ":\n");
98        passwd = strtok(NULL, ":\n");
99        if (!passwd) {
100            passwd = realm;
101            realm = NULL;
102        }
103        if ((strlen(user) > 0) && passwd) {
104            if (strncmp(passwd, "{HHA1}", 6) == 0) {
105                ha1 = passwd + 6;
106                passwd = NULL;
107            } else if (isHa1Mode) {
108                ha1 = passwd;
109                passwd = NULL;
110            }
111            if (ha1 && strlen(ha1) != 32) {
112                /* We cannot accept plaintext passwords when using HA1 encoding,
113                 * as the passwords may be output to cache.log if debugging is on.
114                 */
115                fprintf(stderr, "digest_file_auth: ignoring invalid password for %s\n", user);
116                continue;
117            }
118            u = static_cast<user_data*>(xcalloc(1, sizeof(*u)));
119            if (realm) {
120                int len = strlen(user) + strlen(realm) + 2;
121                u->hash.key = xmalloc(len);
122                snprintf(static_cast<char*>(u->hash.key), len, "%s:%s", user, realm);
123            } else {
124                u->hash.key = xstrdup(user);
125            }
126            if (ha1)
127                u->ha1 = xstrdup(ha1);
128            else
129                u->passwd = xstrdup(passwd);
130            hash_join(hash, &u->hash);
131        }
132    }
133    fclose(f);
134}
135
136/* replace when changing the backend */
137void
138TextArguments(int argc, char **argv)
139{
140    struct stat sb;
141    if (argc == 2)
142        passwdfile = argv[1];
143    if ((argc == 3) && !strcmp("-c", argv[1])) {
144        ha1mode = 1;
145        passwdfile = argv[2];
146    }
147    if (!passwdfile) {
148        fprintf(stderr, "Usage: digest_file_auth [OPTIONS] <passwordfile>\n");
149        fprintf(stderr, "  -c   accept digest hashed passwords rather than plaintext in passwordfile\n");
150        exit(1);
151    }
152    if (stat(passwdfile, &sb) != 0) {
153        fprintf(stderr, "cannot stat %s\n", passwdfile);
154        exit(1);
155    }
156}
157
158static const user_data *
159GetPassword(RequestData * requestData)
160{
161    user_data *u;
162    struct stat sb;
163    char buf[256];
164    int len;
165    if (stat(passwdfile, &sb) == 0) {
166        if (sb.st_mtime != change_time) {
167            read_passwd_file(passwdfile, ha1mode);
168            change_time = sb.st_mtime;
169        }
170    }
171    if (!hash)
172        return NULL;
173    len = snprintf(buf, sizeof(buf), "%s:%s", requestData->user, requestData->realm);
174    if (len >= static_cast<int>(sizeof(buf)))
175        return NULL;
176    u = (user_data*)hash_lookup(hash, buf);
177    if (u)
178        return u;
179    u = (user_data*)hash_lookup(hash, requestData->user);
180    return u;
181}
182
183void
184TextHHA1(RequestData * requestData)
185{
186    const user_data *u = GetPassword(requestData);
187    if (!u) {
188        requestData->error = -1;
189        return;
190    }
191    if (u->ha1) {
192        xstrncpy(requestData->HHA1, u->ha1, sizeof(requestData->HHA1));
193    } else {
194        HASH HA1;
195        DigestCalcHA1("md5", requestData->user, requestData->realm, u->passwd, NULL, NULL, HA1, requestData->HHA1);
196    }
197}
198
Note: See TracBrowser for help on using the repository browser.