Testsuite: Use the configure results in Makefile
[exim.git] / src / src / pdkim / pdkim.h
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1/*
2 * PDKIM - a RFC4871 (DKIM) implementation
3 *
c4ceed07 4 * Copyright (C) 2009 - 2012 Tom Kistner <tom@duncanthrax.net>
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5 *
6 * http://duncanthrax.net/pdkim/
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 */
22
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23/* -------------------------------------------------------------------------- */
24/* Debugging. This can also be enabled/disabled at run-time. I recommend to
25 leave it defined. */
26#define PDKIM_DEBUG
27
28/* -------------------------------------------------------------------------- */
29/* Length of the preallocated buffer for the "answer" from the dns/txt
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30 callback function. This should match the maximum RDLENGTH from DNS. */
31#define PDKIM_DNS_TXT_MAX_RECLEN (1 << 16)
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32
33/* -------------------------------------------------------------------------- */
34/* Function success / error codes */
35#define PDKIM_OK 0
36#define PDKIM_FAIL -1
37#define PDKIM_ERR_OOM -100
38#define PDKIM_ERR_RSA_PRIVKEY -101
39#define PDKIM_ERR_RSA_SIGNING -102
40#define PDKIM_ERR_LONG_LINE -103
41#define PDKIM_ERR_BUFFER_TOO_SMALL -104
42
43/* -------------------------------------------------------------------------- */
44/* Main/Extended verification status */
45#define PDKIM_VERIFY_NONE 0
46#define PDKIM_VERIFY_INVALID 1
47#define PDKIM_VERIFY_FAIL 2
48#define PDKIM_VERIFY_PASS 3
49
50#define PDKIM_VERIFY_FAIL_BODY 1
51#define PDKIM_VERIFY_FAIL_MESSAGE 2
52#define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE 3
53#define PDKIM_VERIFY_INVALID_BUFFER_SIZE 4
54#define PDKIM_VERIFY_INVALID_PUBKEY_PARSING 5
55
56/* -------------------------------------------------------------------------- */
57/* Some parameter values */
58#define PDKIM_QUERYMETHOD_DNS_TXT 0
59
60#define PDKIM_ALGO_RSA_SHA256 0
61#define PDKIM_ALGO_RSA_SHA1 1
62
63#define PDKIM_CANON_SIMPLE 0
64#define PDKIM_CANON_RELAXED 1
65
66#define PDKIM_HASH_SHA256 0
67#define PDKIM_HASH_SHA1 1
68
69#define PDKIM_KEYTYPE_RSA 0
70
71/* -------------------------------------------------------------------------- */
72/* Some required forward declarations, please ignore */
73typedef struct pdkim_stringlist pdkim_stringlist;
74typedef struct pdkim_str pdkim_str;
75typedef struct sha1_context sha1_context;
76typedef struct sha2_context sha2_context;
77#define HAVE_SHA1_CONTEXT
78#define HAVE_SHA2_CONTEXT
79
80/* -------------------------------------------------------------------------- */
81/* Some concessions towards Redmond */
82#ifdef WINDOWS
83#define snprintf _snprintf
84#define strcasecmp _stricmp
85#define strncasecmp _strnicmp
86#define DLLEXPORT __declspec(dllexport)
87#else
88#define DLLEXPORT
89#endif
90
91
92/* -------------------------------------------------------------------------- */
93/* Public key as (usually) fetched from DNS */
94typedef struct pdkim_pubkey {
95 char *version; /* v= */
96 char *granularity; /* g= */
97
98 char *hashes; /* h= */
99 char *keytype; /* k= */
100 char *srvtype; /* s= */
101 char *notes; /* n= */
102
103 char *key; /* p= */
104 int key_len;
105
106 int testing; /* t=y */
107 int no_subdomaining; /* t=s */
108} pdkim_pubkey;
109
110/* -------------------------------------------------------------------------- */
111/* Signature as it appears in a DKIM-Signature header */
112typedef struct pdkim_signature {
113
114 /* Bits stored in a DKIM signature header --------------------------- */
115
116 /* (v=) The version, as an integer. Currently, always "1" */
117 int version;
118
119 /* (a=) The signature algorithm. Either PDKIM_ALGO_RSA_SHA256
120 or PDKIM_ALGO_RSA_SHA1 */
121 int algo;
122
123 /* (c=x/) Header canonicalization method. Either PDKIM_CANON_SIMPLE
124 or PDKIM_CANON_RELAXED */
125 int canon_headers;
126
127 /* (c=/x) Body canonicalization method. Either PDKIM_CANON_SIMPLE
128 or PDKIM_CANON_RELAXED */
129 int canon_body;
130
131 /* (q=) Query Method. Currently, only PDKIM_QUERYMETHOD_DNS_TXT
132 is specified */
133 int querymethod;
134
135 /* (s=) The selector string as given in the signature */
136 char *selector;
137
138 /* (d=) The domain as given in the signature */
139 char *domain;
140
141 /* (i=) The identity as given in the signature */
142 char *identity;
143
144 /* (t=) Timestamp of signature creation */
145 unsigned long created;
146
147 /* (x=) Timestamp of expiry of signature */
148 unsigned long expires;
149
150 /* (l=) Amount of hashed body bytes (after canonicalization). Default
151 is -1. Note: a value of 0 means that the body is unsigned! */
152 long bodylength;
153
154 /* (h=) Colon-separated list of header names that are included in the
155 signature */
156 char *headernames;
157
158 /* (z=) */
159 char *copiedheaders;
160
161 /* (b=) Raw signature data, along with its length in bytes */
162 char *sigdata;
163 int sigdata_len;
164
165 /* (bh=) Raw body hash data, along with its length in bytes */
166 char *bodyhash;
167 int bodyhash_len;
168
169 /* Folded DKIM-Signature: header. Singing only, NULL for verifying.
170 Ready for insertion into the message. Note: Folded using CRLFTB,
171 but final line terminator is NOT included. Note2: This buffer is
172 free()d when you call pdkim_free_ctx(). */
173 char *signature_header;
174
175 /* The main verification status. Verification only. One of:
176
177 PDKIM_VERIFY_NONE Verification was not attempted. This status
178 should not appear.
179
180 PDKIM_VERIFY_INVALID There was an error while trying to verify
181 the signature. A more precise description
182 is available in verify_ext_status.
183
184 PDKIM_VERIFY_FAIL Verification failed because either the body
185 hash did not match, or the signature verification
186 failed. This means the message was modified.
187 Check verify_ext_status for the exact reason.
188
189 PDKIM_VERIFY_PASS Verification succeeded.
190 */
191 int verify_status;
192
193 /* Extended verification status. Verification only. Depending on the value
194 of verify_status, it can contain:
195
196 For verify_status == PDKIM_VERIFY_INVALID:
197
198 PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE
199 Unable to retrieve a public key container.
200
201 PDKIM_VERIFY_INVALID_BUFFER_SIZE
202 Either the DNS name constructed to retrieve the public key record
203 does not fit into PDKIM_DNS_TXT_MAX_NAMELEN bytes, or the retrieved
204 record is longer than PDKIM_DNS_TXT_MAX_RECLEN bytes.
205
206 PDKIM_VERIFY_INVALID_PUBKEY_PARSING
207 (Syntax) error while parsing the retrieved public key record.
208
209
210 For verify_status == PDKIM_VERIFY_FAIL:
211
212 PDKIM_VERIFY_FAIL_BODY
213 The calculated body hash does not match the advertised body hash
214 from the bh= tag of the signature.
215
216 PDKIM_VERIFY_FAIL_MESSAGE
217 RSA verification of the signature (b= tag) failed.
218 */
219 int verify_ext_status;
220
221 /* Pointer to a public key record that was used to verify the signature.
222 See pdkim_pubkey declaration above for more information.
223 Caution: is NULL if signing or if no record was retrieved. */
224 pdkim_pubkey *pubkey;
225
226 /* Pointer to the next pdkim_signature signature. NULL if signing or if
227 this is the last signature. */
228 void *next;
229
230 /* Properties below this point are used internally only ------------- */
231
232 /* Per-signature helper variables ----------------------------------- */
233 sha1_context *sha1_body; /* SHA1 block */
234 sha2_context *sha2_body; /* SHA256 block */
235 unsigned long signed_body_bytes; /* How many body bytes we hashed */
236 pdkim_stringlist *headers; /* Raw headers included in the sig */
237 /* Signing specific ------------------------------------------------- */
238 char *rsa_privkey; /* Private RSA key */
239 char *sign_headers; /* To-be-signed header names */
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240 char *rawsig_no_b_val; /* Original signature header w/o b= tag value. */
241} pdkim_signature;
242
243
244/* -------------------------------------------------------------------------- */
245/* Context to keep state between all operations. */
246#define PDKIM_MODE_SIGN 0
247#define PDKIM_MODE_VERIFY 1
248#define PDKIM_INPUT_NORMAL 0
249#define PDKIM_INPUT_SMTP 1
250typedef struct pdkim_ctx {
251
252 /* PDKIM_MODE_VERIFY or PDKIM_MODE_SIGN */
253 int mode;
254
255 /* PDKIM_INPUT_SMTP or PDKIM_INPUT_NORMAL */
256 int input_mode;
257
258 /* One (signing) or several chained (verification) signatures */
259 pdkim_signature *sig;
260
261 /* Callback for dns/txt query method (verification only) */
262 int(*dns_txt_callback)(char *, char *);
263
264 /* Coder's little helpers */
265 pdkim_str *cur_header;
266 char *linebuf;
267 int linebuf_offset;
268 int seen_lf;
269 int seen_eod;
270 int past_headers;
271 int num_buffered_crlf;
272 int num_headers;
37f8b554 273 pdkim_stringlist *headers; /* Raw headers for verification */
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274
275#ifdef PDKIM_DEBUG
276 /* A FILE pointer. When not NULL, debug output will be generated
277 and sent to this stream */
278 FILE *debug_stream;
279#endif
280
281} pdkim_ctx;
282
283
284/* -------------------------------------------------------------------------- */
285/* API functions. Please see the sample code in sample/test_sign.c and
286 sample/test_verify.c for documentation.
287*/
288
289#ifdef __cplusplus
290extern "C" {
291#endif
292
293DLLEXPORT
294pdkim_ctx *pdkim_init_sign (int, char *, char *, char *);
295
296DLLEXPORT
297pdkim_ctx *pdkim_init_verify (int, int(*)(char *, char *));
298
299DLLEXPORT
300int pdkim_set_optional (pdkim_ctx *, char *, char *,int, int,
301 long, int,
302 unsigned long,
303 unsigned long);
304
305DLLEXPORT
306int pdkim_feed (pdkim_ctx *, char *, int);
307DLLEXPORT
308int pdkim_feed_finish (pdkim_ctx *, pdkim_signature **);
309
310DLLEXPORT
311void pdkim_free_ctx (pdkim_ctx *);
312
313#ifdef PDKIM_DEBUG
314DLLEXPORT
315void pdkim_set_debug_stream(pdkim_ctx *, FILE *);
316#endif
317
318#ifdef __cplusplus
319}
320#endif