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420a0d19 CE |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
5 | /* SRS - Sender rewriting scheme support | |
6 | (C)2004 Miles Wilton <miles@mirtol.com> | |
2ea97746 | 7 | Copyright (c) The Exim Maintainers 2016 |
420a0d19 CE |
8 | |
9 | SRS Support Version: 1.0a | |
10 | ||
11 | License: GPL */ | |
12 | ||
13 | #include "exim.h" | |
14 | #ifdef EXPERIMENTAL_SRS | |
15 | ||
16 | #include <srs_alt.h> | |
17 | #include "srs.h" | |
18 | ||
19 | srs_t *srs = NULL; | |
20 | uschar *srs_db_forward = NULL; | |
21 | uschar *srs_db_reverse = NULL; | |
22 | ||
23 | ||
24 | /* srs_init just initialises libsrs and creates (if necessary) | |
25 | an srs object to use for all srs calls in this instance */ | |
26 | ||
27 | int eximsrs_init() | |
28 | { | |
2ea97746 | 29 | const uschar *list = srs_config; |
420a0d19 CE |
30 | uschar secret_buf[SRS_MAX_SECRET_LENGTH]; |
31 | uschar *secret = NULL; | |
32 | uschar sbuf[4]; | |
33 | uschar *sbufp; | |
34 | ||
35 | /* Check if this instance of Exim has not initialized SRS */ | |
36 | if(srs == NULL) | |
37 | { | |
38 | int co = 0; | |
39 | int hashlen, maxage; | |
40 | BOOL usetimestamp, usehash; | |
41 | ||
42 | /* Copy config vars */ | |
43 | hashlen = srs_hashlength; | |
44 | maxage = srs_maxage; | |
45 | usetimestamp = srs_usetimestamp; | |
46 | usehash = srs_usehash; | |
47 | ||
48 | /* Pass srs_config var (overrides new config vars) */ | |
49 | co = 0; | |
50 | if(srs_config != NULL) | |
51 | { | |
52 | secret = string_nextinlist(&list, &co, secret_buf, SRS_MAX_SECRET_LENGTH); | |
53 | ||
54 | if((sbufp = string_nextinlist(&list, &co, sbuf, sizeof(sbuf))) != NULL) | |
55 | maxage = atoi(sbuf); | |
56 | ||
57 | if((sbufp = string_nextinlist(&list, &co, sbuf, sizeof(sbuf))) != NULL) | |
58 | hashlen = atoi(sbuf); | |
59 | ||
60 | if((sbufp = string_nextinlist(&list, &co, sbuf, sizeof(sbuf))) != NULL) | |
61 | usetimestamp = atoi(sbuf); | |
62 | ||
63 | if((sbufp = string_nextinlist(&list, &co, sbuf, sizeof(sbuf))) != NULL) | |
64 | usehash = atoi(sbuf); | |
65 | } | |
66 | ||
67 | if(srs_hashmin == -1) | |
68 | srs_hashmin = hashlen; | |
69 | ||
70 | /* First secret specified in secrets? */ | |
71 | co = 0; | |
72 | list = srs_secrets; | |
73 | if(secret == NULL || *secret == '\0') | |
74 | { | |
75 | if((secret = string_nextinlist(&list, &co, secret_buf, SRS_MAX_SECRET_LENGTH)) == NULL) | |
76 | { | |
77 | log_write(0, LOG_MAIN | LOG_PANIC, | |
78 | "SRS Configuration Error: No secret specified"); | |
79 | return DEFER; | |
80 | } | |
81 | } | |
82 | ||
83 | /* Check config */ | |
84 | if(maxage < 0 || maxage > 365) | |
85 | { | |
86 | log_write(0, LOG_MAIN | LOG_PANIC, | |
87 | "SRS Configuration Error: Invalid maximum timestamp age"); | |
88 | return DEFER; | |
89 | } | |
90 | if(hashlen < 1 || hashlen > 20 || srs_hashmin < 1 || srs_hashmin > 20) | |
91 | { | |
92 | log_write(0, LOG_MAIN | LOG_PANIC, | |
93 | "SRS Configuration Error: Invalid hash length"); | |
94 | return DEFER; | |
95 | } | |
96 | ||
97 | if((srs = srs_open(secret, Ustrlen(secret), maxage, hashlen, srs_hashmin)) == NULL) | |
98 | { | |
99 | log_write(0, LOG_MAIN | LOG_PANIC, | |
100 | "Failed to allocate SRS memory"); | |
101 | return DEFER; | |
102 | } | |
103 | ||
104 | srs_set_option(srs, SRS_OPTION_USETIMESTAMP, usetimestamp); | |
105 | srs_set_option(srs, SRS_OPTION_USEHASH, usehash); | |
106 | ||
107 | /* Extra secrets? */ | |
108 | while((secret = string_nextinlist(&list, &co, secret_buf, SRS_MAX_SECRET_LENGTH)) != NULL) | |
109 | srs_add_secret(srs, secret, (Ustrlen(secret) > SRS_MAX_SECRET_LENGTH) ? SRS_MAX_SECRET_LENGTH : Ustrlen(secret)); | |
110 | ||
111 | DEBUG(D_any) | |
112 | debug_printf("SRS initialized\n"); | |
113 | } | |
114 | ||
115 | return OK; | |
116 | } | |
117 | ||
118 | ||
119 | int eximsrs_done() | |
120 | { | |
121 | if(srs != NULL) | |
122 | srs_close(srs); | |
123 | ||
124 | srs = NULL; | |
125 | ||
126 | return OK; | |
127 | } | |
128 | ||
129 | ||
130 | int eximsrs_forward(uschar **result, uschar *orig_sender, uschar *domain) | |
131 | { | |
132 | char res[512]; | |
133 | int n; | |
134 | ||
135 | if((n = srs_forward(srs, orig_sender, domain, res, sizeof(res))) & SRS_RESULT_FAIL) | |
136 | { | |
137 | DEBUG(D_any) | |
138 | debug_printf("srs_forward failed (%s, %s): %s\n", orig_sender, domain, srs_geterrormsg(n)); | |
139 | return DEFER; | |
140 | } | |
141 | ||
142 | *result = string_copy(res); | |
143 | return OK; | |
144 | } | |
145 | ||
146 | ||
147 | int eximsrs_reverse(uschar **result, uschar *address) | |
148 | { | |
149 | char res[512]; | |
150 | int n; | |
151 | ||
152 | if((n = srs_reverse(srs, address, res, sizeof(res))) & SRS_RESULT_FAIL) | |
153 | { | |
154 | DEBUG(D_any) | |
155 | debug_printf("srs_reverse failed (%s): %s\n", address, srs_geterrormsg(n)); | |
156 | if(n == SRS_RESULT_NOTSRS || n == SRS_RESULT_BADSRS) | |
157 | return DECLINE; | |
158 | if(n == SRS_RESULT_BADHASH || n == SRS_RESULT_BADTIMESTAMP || n == SRS_RESULT_TIMESTAMPEXPIRED) | |
159 | return FAIL; | |
160 | return DEFER; | |
161 | } | |
162 | ||
163 | *result = string_copy(res); | |
164 | return OK; | |
165 | } | |
166 | ||
167 | ||
168 | int eximsrs_db_set(BOOL reverse, uschar *srs_db) | |
169 | { | |
170 | if(reverse) | |
171 | srs_db_reverse = (srs_db == NULL ? NULL : string_copy(srs_db)); | |
172 | else | |
173 | srs_db_forward = (srs_db == NULL ? NULL : string_copy(srs_db)); | |
174 | ||
175 | if(srs_set_db_functions(srs, (srs_db_forward ? eximsrs_db_insert : NULL), | |
176 | (srs_db_reverse ? eximsrs_db_lookup : NULL)) & SRS_RESULT_FAIL) | |
177 | return DEFER; | |
178 | ||
179 | return OK; | |
180 | } | |
181 | ||
182 | ||
183 | srs_result eximsrs_db_insert(srs_t *srs, char *data, uint data_len, char *result, uint result_len) | |
184 | { | |
185 | uschar *res; | |
186 | uschar buf[64]; | |
187 | ||
188 | if(srs_db_forward == NULL) | |
189 | return SRS_RESULT_DBERROR; | |
190 | ||
191 | srs_db_address = string_copyn(data, data_len); | |
192 | if(srs_generate_unique_id(srs, srs_db_address, buf, 64) & SRS_RESULT_FAIL) | |
193 | return SRS_RESULT_DBERROR; | |
194 | ||
195 | srs_db_key = string_copyn(buf, 16); | |
196 | ||
197 | if((res = expand_string(srs_db_forward)) == NULL) | |
198 | return SRS_RESULT_DBERROR; | |
199 | ||
200 | if(result_len < 17) | |
201 | return SRS_RESULT_DBERROR; | |
202 | ||
203 | Ustrncpy(result, srs_db_key, result_len); | |
204 | ||
205 | return SRS_RESULT_OK; | |
206 | } | |
207 | ||
208 | ||
209 | srs_result eximsrs_db_lookup(srs_t *srs, char *data, uint data_len, char *result, uint result_len) | |
210 | { | |
211 | uschar *res; | |
212 | ||
213 | if(srs_db_reverse == NULL) | |
214 | return SRS_RESULT_DBERROR; | |
215 | ||
216 | srs_db_key = string_copyn(data, data_len); | |
217 | if((res = expand_string(srs_db_reverse)) == NULL) | |
218 | return SRS_RESULT_DBERROR; | |
219 | ||
220 | if(Ustrlen(res) >= result_len) | |
221 | return SRS_RESULT_ADDRESSTOOLONG; | |
222 | ||
223 | strncpy(result, res, result_len); | |
224 | ||
225 | return SRS_RESULT_OK; | |
226 | } | |
227 | ||
228 | ||
229 | #endif | |
230 |