Testsuite: ensure logging path is set
[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>
f9ba5e22 5 * Copyright (c) 2016 - 2018 Jeremy Harris
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6 *
7 * http://duncanthrax.net/pdkim/
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 */
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23#ifndef PDKIM_H
24#define PDKIM_H
25
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26#include "../blob.h"
27#include "../hash.h"
80a47a2c 28
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29#define PDKIM_DEFAULT_SIGN_HEADERS "From:Sender:Reply-To:Subject:Date:"\
30 "Message-ID:To:Cc:MIME-Version:Content-Type:"\
31 "Content-Transfer-Encoding:Content-ID:"\
32 "Content-Description:Resent-Date:Resent-From:"\
33 "Resent-Sender:Resent-To:Resent-Cc:"\
34 "Resent-Message-ID:In-Reply-To:References:"\
35 "List-Id:List-Help:List-Unsubscribe:"\
36 "List-Subscribe:List-Post:List-Owner:List-Archive"
37
80a47a2c 38/* -------------------------------------------------------------------------- */
80a47a2c 39/* Length of the preallocated buffer for the "answer" from the dns/txt
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40 callback function. This should match the maximum RDLENGTH from DNS. */
41#define PDKIM_DNS_TXT_MAX_RECLEN (1 << 16)
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42
43/* -------------------------------------------------------------------------- */
44/* Function success / error codes */
45#define PDKIM_OK 0
46#define PDKIM_FAIL -1
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47#define PDKIM_ERR_RSA_PRIVKEY -101
48#define PDKIM_ERR_RSA_SIGNING -102
49#define PDKIM_ERR_LONG_LINE -103
50#define PDKIM_ERR_BUFFER_TOO_SMALL -104
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51#define PDKIM_SIGN_PRIVKEY_WRAP -105
52#define PDKIM_SIGN_PRIVKEY_B64D -106
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53
54/* -------------------------------------------------------------------------- */
55/* Main/Extended verification status */
56#define PDKIM_VERIFY_NONE 0
57#define PDKIM_VERIFY_INVALID 1
58#define PDKIM_VERIFY_FAIL 2
59#define PDKIM_VERIFY_PASS 3
dfbcb5ac 60#define PDKIM_VERIFY_POLICY BIT(31)
80a47a2c 61
07eeb4df 62#define PDKIM_VERIFY_FAIL_BODY 1
63#define PDKIM_VERIFY_FAIL_MESSAGE 2
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64#define PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH 3
65#define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE 4
66#define PDKIM_VERIFY_INVALID_BUFFER_SIZE 5
67#define PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD 6
68#define PDKIM_VERIFY_INVALID_PUBKEY_IMPORT 7
69#define PDKIM_VERIFY_INVALID_SIGNATURE_ERROR 8
70#define PDKIM_VERIFY_INVALID_DKIM_VERSION 9
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71
72/* -------------------------------------------------------------------------- */
73/* Some parameter values */
74#define PDKIM_QUERYMETHOD_DNS_TXT 0
75
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76/*#define PDKIM_ALGO_RSA_SHA256 0 */
77/*#define PDKIM_ALGO_RSA_SHA1 1 */
78
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79#define PDKIM_CANON_SIMPLE 0
80#define PDKIM_CANON_RELAXED 1
81
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82/* -------------------------------------------------------------------------- */
83/* Some required forward declarations, please ignore */
84typedef struct pdkim_stringlist pdkim_stringlist;
85typedef struct pdkim_str pdkim_str;
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86typedef struct sha1_context sha1_context;
87typedef struct sha2_context sha2_context;
88#define HAVE_SHA1_CONTEXT
89#define HAVE_SHA2_CONTEXT
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90
91/* -------------------------------------------------------------------------- */
92/* Some concessions towards Redmond */
93#ifdef WINDOWS
94#define snprintf _snprintf
95#define strcasecmp _stricmp
96#define strncasecmp _strnicmp
97#define DLLEXPORT __declspec(dllexport)
98#else
99#define DLLEXPORT
100#endif
101
102
103/* -------------------------------------------------------------------------- */
104/* Public key as (usually) fetched from DNS */
105typedef struct pdkim_pubkey {
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106 const uschar * version; /* v= */
107 const uschar *granularity; /* g= */
80a47a2c 108
35cf75e9 109 const uschar * hashes; /* h= */
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110 const uschar * keytype; /* k= */
111 const uschar * srvtype; /* s= */
e2e3255a 112 uschar *notes; /* n= */
80a47a2c 113
2592e6c0 114 blob key; /* p= */
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115 int testing; /* t=y */
116 int no_subdomaining; /* t=s */
117} pdkim_pubkey;
118
119/* -------------------------------------------------------------------------- */
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120/* Body-hash to be calculated */
121typedef struct pdkim_bodyhash {
122 struct pdkim_bodyhash * next;
123 int hashtype;
124 int canon_method;
125 long bodylength;
126
127 hctx body_hash_ctx;
128 unsigned long signed_body_bytes; /* done so far */
129 int num_buffered_blanklines;
130
131 blob bh; /* completed hash */
132} pdkim_bodyhash;
133
134/* -------------------------------------------------------------------------- */
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135/* Signature as it appears in a DKIM-Signature header */
136typedef struct pdkim_signature {
9e70917d 137 struct pdkim_signature * next;
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138
139 /* Bits stored in a DKIM signature header --------------------------- */
140
141 /* (v=) The version, as an integer. Currently, always "1" */
142 int version;
143
286b9d5f 144 /* (a=) The signature algorithm. Either PDKIM_ALGO_RSA_SHA256 */
cf1cce5e 145 int keytype; /* pdkim_keytypes index */
d73e45df 146 int hashtype; /* pdkim_hashes index */
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147
148 /* (c=x/) Header canonicalization method. Either PDKIM_CANON_SIMPLE
149 or PDKIM_CANON_RELAXED */
150 int canon_headers;
151
152 /* (c=/x) Body canonicalization method. Either PDKIM_CANON_SIMPLE
153 or PDKIM_CANON_RELAXED */
154 int canon_body;
155
156 /* (q=) Query Method. Currently, only PDKIM_QUERYMETHOD_DNS_TXT
157 is specified */
158 int querymethod;
159
160 /* (s=) The selector string as given in the signature */
e2e3255a 161 uschar *selector;
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162
163 /* (d=) The domain as given in the signature */
e2e3255a 164 uschar *domain;
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165
166 /* (i=) The identity as given in the signature */
e2e3255a 167 uschar *identity;
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168
169 /* (t=) Timestamp of signature creation */
170 unsigned long created;
171
172 /* (x=) Timestamp of expiry of signature */
173 unsigned long expires;
174
175 /* (l=) Amount of hashed body bytes (after canonicalization). Default
176 is -1. Note: a value of 0 means that the body is unsigned! */
177 long bodylength;
178
179 /* (h=) Colon-separated list of header names that are included in the
180 signature */
2592e6c0 181 uschar *headernames;
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182
183 /* (z=) */
e2e3255a 184 uschar *copiedheaders;
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185
186 /* (b=) Raw signature data, along with its length in bytes */
dcd03763 187 blob sighash;
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188
189 /* (bh=) Raw body hash data, along with its length in bytes */
2592e6c0 190 blob bodyhash;
80a47a2c 191
9e70917d 192 /* Folded DKIM-Signature: header. Signing only, NULL for verifying.
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193 Ready for insertion into the message. Note: Folded using CRLFTB,
194 but final line terminator is NOT included. Note2: This buffer is
195 free()d when you call pdkim_free_ctx(). */
e2e3255a 196 uschar *signature_header;
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197
198 /* The main verification status. Verification only. One of:
199
200 PDKIM_VERIFY_NONE Verification was not attempted. This status
201 should not appear.
202
203 PDKIM_VERIFY_INVALID There was an error while trying to verify
204 the signature. A more precise description
205 is available in verify_ext_status.
206
207 PDKIM_VERIFY_FAIL Verification failed because either the body
208 hash did not match, or the signature verification
209 failed. This means the message was modified.
210 Check verify_ext_status for the exact reason.
211
212 PDKIM_VERIFY_PASS Verification succeeded.
213 */
214 int verify_status;
215
216 /* Extended verification status. Verification only. Depending on the value
217 of verify_status, it can contain:
218
219 For verify_status == PDKIM_VERIFY_INVALID:
220
221 PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE
222 Unable to retrieve a public key container.
223
224 PDKIM_VERIFY_INVALID_BUFFER_SIZE
225 Either the DNS name constructed to retrieve the public key record
226 does not fit into PDKIM_DNS_TXT_MAX_NAMELEN bytes, or the retrieved
227 record is longer than PDKIM_DNS_TXT_MAX_RECLEN bytes.
228
229 PDKIM_VERIFY_INVALID_PUBKEY_PARSING
230 (Syntax) error while parsing the retrieved public key record.
231
232
233 For verify_status == PDKIM_VERIFY_FAIL:
234
235 PDKIM_VERIFY_FAIL_BODY
236 The calculated body hash does not match the advertised body hash
237 from the bh= tag of the signature.
238
239 PDKIM_VERIFY_FAIL_MESSAGE
240 RSA verification of the signature (b= tag) failed.
241 */
242 int verify_ext_status;
243
244 /* Pointer to a public key record that was used to verify the signature.
245 See pdkim_pubkey declaration above for more information.
246 Caution: is NULL if signing or if no record was retrieved. */
247 pdkim_pubkey *pubkey;
248
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249 /* Properties below this point are used internally only ------------- */
250
251 /* Per-signature helper variables ----------------------------------- */
cf1cce5e 252 pdkim_bodyhash *calc_body_hash; /* hash to be / being calculated */
2592e6c0 253
cf1cce5e 254 pdkim_stringlist *headers; /* Raw headers included in the sig */
9e70917d 255
80a47a2c 256 /* Signing specific ------------------------------------------------- */
d73e45df 257 uschar * privkey; /* Private key */
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258 uschar * sign_headers; /* To-be-signed header names */
259 uschar * rawsig_no_b_val; /* Original signature header w/o b= tag value. */
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260} pdkim_signature;
261
262
263/* -------------------------------------------------------------------------- */
264/* Context to keep state between all operations. */
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265typedef struct pdkim_ctx {
266
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267#define PDKIM_MODE_SIGN BIT(0) /* if unset, mode==verify */
268#define PDKIM_DOT_TERM BIT(1) /* dot termination and unstuffing */
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269#define PDKIM_SEEN_CR BIT(2)
270#define PDKIM_SEEN_LF BIT(3)
e983e85a 271#define PDKIM_PAST_HDRS BIT(4)
b895f4b2 272#define PDKIM_SEEN_EOD BIT(5)
e983e85a 273 unsigned flags;
80a47a2c 274
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275 /* One (signing) or several chained (verification) signatures */
276 pdkim_signature *sig;
277
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278 /* One (signing) or several chained (verification) bodyhashes */
279 pdkim_bodyhash *bodyhash;
280
80a47a2c 281 /* Callback for dns/txt query method (verification only) */
1eedc10f 282 uschar * (*dns_txt_callback)(char *);
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283
284 /* Coder's little helpers */
acec9514 285 gstring *cur_header;
7845dbb3 286 uschar *linebuf;
80a47a2c 287 int linebuf_offset;
80a47a2c 288 int num_headers;
37f8b554 289 pdkim_stringlist *headers; /* Raw headers for verification */
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290} pdkim_ctx;
291
292
293/* -------------------------------------------------------------------------- */
294/* API functions. Please see the sample code in sample/test_sign.c and
295 sample/test_verify.c for documentation.
296*/
297
298#ifdef __cplusplus
299extern "C" {
300#endif
301
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302void pdkim_init (void);
303
1eedc10f 304void pdkim_init_context (pdkim_ctx *, BOOL, uschar * (*)(char *));
9e70917d 305
80a47a2c 306DLLEXPORT
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307pdkim_signature *pdkim_init_sign (pdkim_ctx *,
308 uschar *, uschar *, uschar *, uschar *,
309 const uschar **);
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310
311DLLEXPORT
1eedc10f 312pdkim_ctx *pdkim_init_verify (uschar * (*)(char *), BOOL);
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313
314DLLEXPORT
9e70917d 315void pdkim_set_optional (pdkim_signature *, char *, char *,int, int,
f444c2c7 316 long,
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317 unsigned long,
318 unsigned long);
319
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320pdkim_bodyhash *pdkim_set_bodyhash(pdkim_ctx *, pdkim_signature *);
321
80a47a2c 322DLLEXPORT
ef698bf6 323int pdkim_feed (pdkim_ctx *, uschar *, int);
80a47a2c 324DLLEXPORT
b9df1829 325int pdkim_feed_finish (pdkim_ctx *, pdkim_signature **, const uschar **);
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326
327DLLEXPORT
328void pdkim_free_ctx (pdkim_ctx *);
329
f7302073 330
b9df1829 331const uschar * pdkim_errstr(int);
f7302073 332
9e70917d 333uschar * dkim_sig_to_a_tag(const pdkim_signature * sig);
d73e45df 334
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335#ifdef __cplusplus
336}
337#endif
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338
339#endif