summaryrefslogtreecommitdiff
path: root/sasl_defs.c
blob: e73a5707aca77010528f7c1f700c65d4a8b0abcc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
#include "memcached.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sasl/saslplug.h>

char my_sasl_hostname[1025];

#if defined(HAVE_SASL_CB_GETCONF) || defined(HAVE_SASL_CB_GETCONFPATH)
/* The locations we may search for a SASL config file if the user didn't
 * specify one in the environment variable SASL_CONF_PATH
 */
const char * const locations[] = {
    "/etc/sasl/memcached.conf",
    "/etc/sasl2/memcached.conf",
    NULL
};

/* If the element of locations is file, locations_dir_path stores the
 * directory path of these elements */
const char *const locations_dir_path[] = {
    "/etc/sasl",
    "/etc/sasl2",
    NULL
};

/* If the element of locations is directory, locations_file_path stores
 * the actual configure file which used by sasl, when GETCONFPATH is
 * enabled */
const char *const locations_file_path[] = {
    "/etc/sasl/memcached.conf/memcached.conf",
    "/etc/sasl2/memcached.conf/memcached.conf",
    NULL
};
#endif

#ifndef HAVE_SASL_CALLBACK_FT
typedef int (*sasl_callback_ft)(void);
#endif

#ifdef ENABLE_SASL_PWDB
#define MAX_ENTRY_LEN 256

static const char *memcached_sasl_pwdb;

static int sasl_server_userdb_checkpass(sasl_conn_t *conn,
                                        void *context,
                                        const char *user,
                                        const char *pass,
                                        unsigned passlen,
                                        struct propctx *propctx)
{
    size_t unmlen = strlen(user);
    if ((passlen + unmlen) > (MAX_ENTRY_LEN - 4)) {
        fprintf(stderr,
                "WARNING: Failed to authenticate <%s> due to too long password (%d)\n",
                user, passlen);
        return SASL_NOAUTHZ;
    }

    FILE *pwfile = fopen(memcached_sasl_pwdb, "r");
    if (pwfile == NULL) {
        if (settings.verbose) {
            vperror("WARNING: Failed to open sasl database <%s>",
                    memcached_sasl_pwdb);
        }
        return SASL_NOAUTHZ;
    }

    char buffer[MAX_ENTRY_LEN];
    bool ok = false;

    while ((fgets(buffer, sizeof(buffer), pwfile)) != NULL) {
        if (memcmp(user, buffer, unmlen) == 0 && buffer[unmlen] == ':') {
            /* This is the correct user */
            ++unmlen;
            if (memcmp(pass, buffer + unmlen, passlen) == 0 &&
                (buffer[unmlen + passlen] == ':' || /* Additional tokens */
                 buffer[unmlen + passlen] == '\n' || /* end of line */
                 buffer[unmlen + passlen] == '\r'|| /* dos format? */
                 buffer[unmlen + passlen] == '\0')) { /* line truncated */
                ok = true;
            }

            break;
        }
    }
    (void)fclose(pwfile);
    if (ok) {
        return SASL_OK;
    }

    if (settings.verbose) {
        fprintf(stderr, "INFO: User <%s> failed to authenticate\n", user);
    }

    return SASL_NOAUTHZ;
}
#endif

#if defined(HAVE_SASL_CB_GETCONF) || defined(HAVE_SASL_CB_GETCONFPATH)
static int sasl_getconf(void *context, const char **path)
{
    *path = getenv("SASL_CONF_PATH");

    if (*path == NULL) {
#if defined(HAVE_SASL_CB_GETCONF)
        for (int i = 0; locations[i] != NULL; ++i) {
            if (access(locations[i], F_OK) == 0) {
                *path = locations[i];
                break;
            }
        }
#elif defined(HAVE_SASL_CB_GETCONFPATH)
        for (int i = 0; locations[i] != NULL; ++i) {
            if (access(locations_file_path[i], F_OK) == 0) {
                *path = locations[i];
                break;
            } else if (access(locations[i], F_OK) == 0) {
                *path = locations_dir_path[i];
                break;
            }
        }
#endif
    }

    if (settings.verbose) {
        if (*path != NULL) {
            fprintf(stderr, "Reading configuration from: <%s>\n", *path);
        } else {
            fprintf(stderr, "Failed to locate a config path\n");
        }

    }

    return (*path != NULL) ? SASL_OK : SASL_FAIL;
}
#endif

static int sasl_log(void *context, int level, const char *message)
{
    bool log = true;

    switch (level) {
    case SASL_LOG_NONE:
        log = false;
        break;
    case SASL_LOG_PASS:
    case SASL_LOG_TRACE:
    case SASL_LOG_DEBUG:
    case SASL_LOG_NOTE:
        if (settings.verbose < 2) {
            log = false;
        }
        break;
    case SASL_LOG_WARN:
    case SASL_LOG_FAIL:
        if (settings.verbose < 1) {
            log = false;
        }
        break;
    default:
        /* This is an error */
        ;
    }

    if (log) {
        fprintf(stderr, "SASL (severity %d): %s\n", level, message);
    }

    return SASL_OK;
}

static sasl_callback_t sasl_callbacks[] = {
#ifdef ENABLE_SASL_PWDB
   { SASL_CB_SERVER_USERDB_CHECKPASS, (sasl_callback_ft)sasl_server_userdb_checkpass, NULL },
#endif

   { SASL_CB_LOG, (sasl_callback_ft)sasl_log, NULL },

#ifdef HAVE_SASL_CB_GETCONF
   { SASL_CB_GETCONF, sasl_getconf, NULL },
#else
#ifdef HAVE_SASL_CB_GETCONFPATH
   { SASL_CB_GETCONFPATH, (sasl_callback_ft)sasl_getconf, NULL },
#endif
#endif

   { SASL_CB_LIST_END, NULL, NULL }
};

void init_sasl(void) {
#ifdef ENABLE_SASL_PWDB
    memcached_sasl_pwdb = getenv("MEMCACHED_SASL_PWDB");
    if (memcached_sasl_pwdb == NULL) {
       if (settings.verbose) {
          fprintf(stderr,
                  "INFO: MEMCACHED_SASL_PWDB not specified. "
                  "Internal passwd database disabled\n");
       }
       sasl_callbacks[0].id = SASL_CB_LIST_END;
       sasl_callbacks[0].proc = NULL;
    }
#endif

    memset(my_sasl_hostname, 0, sizeof(my_sasl_hostname));
    if (gethostname(my_sasl_hostname, sizeof(my_sasl_hostname)-1) == -1) {
        if (settings.verbose) {
            fprintf(stderr, "Error discovering hostname for SASL\n");
        }
        my_sasl_hostname[0] = '\0';
    }

    if (sasl_server_init(sasl_callbacks, "memcached") != SASL_OK) {
        fprintf(stderr, "Error initializing sasl.\n");
        exit(EXIT_FAILURE);
    } else {
        if (settings.verbose) {
            fprintf(stderr, "Initialized SASL.\n");
        }
    }
}