[exim.git] / src / src / pdkim / pdkim.h

/*
 *  PDKIM - a RFC4871 (DKIM) implementation
 *
 *  Copyright (C) 2009 - 2012  Tom Kistner <tom@duncanthrax.net>
 *  Copyright (c) 2016 - 2018  Jeremy Harris
 *
 *  http://duncanthrax.net/pdkim/
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef PDKIM_H
#define PDKIM_H

#include "../blob.h"
#include "../hash.h"

#define PDKIM_DEFAULT_SIGN_HEADERS "From:Sender:Reply-To:Subject:Date:"\
                             "Message-ID:To:Cc:MIME-Version:Content-Type:"\
                             "Content-Transfer-Encoding:Content-ID:"\
                             "Content-Description:Resent-Date:Resent-From:"\
                             "Resent-Sender:Resent-To:Resent-Cc:"\
                             "Resent-Message-ID:In-Reply-To:References:"\
                             "List-Id:List-Help:List-Unsubscribe:"\
                             "List-Subscribe:List-Post:List-Owner:List-Archive"

/* -------------------------------------------------------------------------- */
/* Length of the preallocated buffer for the "answer" from the dns/txt
   callback function. This should match the maximum RDLENGTH from DNS. */
#define PDKIM_DNS_TXT_MAX_RECLEN    (1 << 16)

/* -------------------------------------------------------------------------- */
/* Function success / error codes */
#define PDKIM_OK                      0
#define PDKIM_FAIL                   -1
#define PDKIM_ERR_RSA_PRIVKEY      -101
#define PDKIM_ERR_RSA_SIGNING      -102
#define PDKIM_ERR_LONG_LINE        -103
#define PDKIM_ERR_BUFFER_TOO_SMALL -104
#define PDKIM_SIGN_PRIVKEY_WRAP    -105
#define PDKIM_SIGN_PRIVKEY_B64D    -106

/* -------------------------------------------------------------------------- */
/* Main/Extended verification status */
#define PDKIM_VERIFY_NONE      0
#define PDKIM_VERIFY_INVALID   1
#define PDKIM_VERIFY_FAIL      2
#define PDKIM_VERIFY_PASS      3
#define PDKIM_VERIFY_POLICY    BIT(31)

#define PDKIM_VERIFY_FAIL_BODY                    1
#define PDKIM_VERIFY_FAIL_MESSAGE                 2
#define PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH	  3
#define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE   4
#define PDKIM_VERIFY_INVALID_BUFFER_SIZE          5
#define PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD     6
#define PDKIM_VERIFY_INVALID_PUBKEY_IMPORT        7
#define PDKIM_VERIFY_INVALID_SIGNATURE_ERROR      8
#define PDKIM_VERIFY_INVALID_DKIM_VERSION         9

/* -------------------------------------------------------------------------- */
/* Some parameter values */
#define PDKIM_QUERYMETHOD_DNS_TXT 0

/*#define PDKIM_ALGO_RSA_SHA256     0 */
/*#define PDKIM_ALGO_RSA_SHA1       1 */

#define PDKIM_CANON_SIMPLE        0
#define PDKIM_CANON_RELAXED       1

/* -------------------------------------------------------------------------- */
/* Some required forward declarations, please ignore */
typedef struct pdkim_stringlist pdkim_stringlist;
typedef struct pdkim_str pdkim_str;
typedef struct sha1_context sha1_context;
typedef struct sha2_context sha2_context;
#define HAVE_SHA1_CONTEXT
#define HAVE_SHA2_CONTEXT

/* -------------------------------------------------------------------------- */
/* Some concessions towards Redmond */
#ifdef WINDOWS
#define snprintf _snprintf
#define strcasecmp _stricmp
#define strncasecmp _strnicmp
#define DLLEXPORT __declspec(dllexport)
#else
#define DLLEXPORT
#endif


/* -------------------------------------------------------------------------- */
/* Public key as (usually) fetched from DNS */
typedef struct pdkim_pubkey {
  const uschar * version;         /* v=  */
  const uschar *granularity;      /* g=  */

  const uschar * hashes;          /* h=  */
  const uschar * keytype;         /* k=  */
  const uschar * srvtype;         /* s=  */
  uschar *notes;                  /* n=  */

  blob  key;                      /* p=  */
  int   testing;                  /* t=y */
  int   no_subdomaining;          /* t=s */
} pdkim_pubkey;

/* -------------------------------------------------------------------------- */
/* Body-hash to be calculated */
typedef struct pdkim_bodyhash {
  struct pdkim_bodyhash *	next;
  int				hashtype;
  int 				canon_method;
  long				bodylength;

  hctx         			body_hash_ctx;
  unsigned long			signed_body_bytes;	/* done so far */
  int				num_buffered_blanklines;

  blob				bh;			/* completed hash */
} pdkim_bodyhash;

/* -------------------------------------------------------------------------- */
/* Signature as it appears in a DKIM-Signature header */
typedef struct pdkim_signature {
  struct pdkim_signature * next;

  /* Bits stored in a DKIM signature header --------------------------- */

  /* (v=) The version, as an integer. Currently, always "1" */
  int version;

  /* (a=) The signature algorithm. Either PDKIM_ALGO_RSA_SHA256 */
  int keytype;	/* pdkim_keytypes index */
  int hashtype;	/* pdkim_hashes index */

  /* (c=x/) Header canonicalization method. Either PDKIM_CANON_SIMPLE
     or PDKIM_CANON_RELAXED */
  int canon_headers;

  /* (c=/x) Body canonicalization method. Either PDKIM_CANON_SIMPLE
     or PDKIM_CANON_RELAXED */
  int canon_body;

  /* (q=) Query Method. Currently, only PDKIM_QUERYMETHOD_DNS_TXT
     is specified */
  int querymethod;

  /* (s=) The selector string as given in the signature */
  uschar *selector;

  /* (d=) The domain as given in the signature */
  uschar *domain;

  /* (i=) The identity as given in the signature */
  uschar *identity;

  /* (t=) Timestamp of signature creation */
  unsigned long created;

  /* (x=) Timestamp of expiry of signature */
  unsigned long expires;

  /* (l=) Amount of hashed body bytes (after canonicalization). Default
     is -1. Note: a value of 0 means that the body is unsigned! */
  long bodylength;

  /* (h=) Colon-separated list of header names that are included in the
     signature */
  uschar *headernames;

  /* (z=) */
  uschar *copiedheaders;

  /* (b=) Raw signature data, along with its length in bytes */
  blob sighash;

  /* (bh=) Raw body hash data, along with its length in bytes */
  blob bodyhash;

  /* Folded DKIM-Signature: header. Signing only, NULL for verifying.
     Ready for insertion into the message. Note: Folded using CRLFTB,
     but final line terminator is NOT included. Note2: This buffer is
     free()d when you call pdkim_free_ctx(). */
  uschar *signature_header;

  /* The main verification status. Verification only. One of:

     PDKIM_VERIFY_NONE      Verification was not attempted. This status
                            should not appear.

     PDKIM_VERIFY_INVALID   There was an error while trying to verify
                            the signature. A more precise description
                            is available in verify_ext_status.

     PDKIM_VERIFY_FAIL      Verification failed because either the body
                            hash did not match, or the signature verification
                            failed. This means the message was modified.
                            Check verify_ext_status for the exact reason.

     PDKIM_VERIFY_PASS      Verification succeeded.
  */
  int verify_status;

  /* Extended verification status. Verification only. Depending on the value
     of verify_status, it can contain:

     For verify_status == PDKIM_VERIFY_INVALID:

        PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE
          Unable to retrieve a public key container.

        PDKIM_VERIFY_INVALID_BUFFER_SIZE
          Either the DNS name constructed to retrieve the public key record
          does not fit into PDKIM_DNS_TXT_MAX_NAMELEN bytes, or the retrieved
          record is longer than PDKIM_DNS_TXT_MAX_RECLEN bytes.

        PDKIM_VERIFY_INVALID_PUBKEY_PARSING
          (Syntax) error while parsing the retrieved public key record.


     For verify_status == PDKIM_VERIFY_FAIL:

        PDKIM_VERIFY_FAIL_BODY
          The calculated body hash does not match the advertised body hash
          from the bh= tag of the signature.

        PDKIM_VERIFY_FAIL_MESSAGE
          RSA verification of the signature (b= tag) failed.
  */
  int verify_ext_status;

  /* Pointer to a public key record that was used to verify the signature.
     See pdkim_pubkey declaration above for more information.
     Caution: is NULL if signing or if no record was retrieved. */
  pdkim_pubkey *pubkey;

  /* Properties below this point are used internally only ------------- */

  /* Per-signature helper variables ----------------------------------- */
  pdkim_bodyhash *calc_body_hash;	/* hash to be / being calculated */

  pdkim_stringlist *headers;		/* Raw headers included in the sig */

  /* Signing specific ------------------------------------------------- */
  uschar * privkey;	     /* Private key                                 */
  uschar * sign_headers;    /* To-be-signed header names                   */
  uschar * rawsig_no_b_val; /* Original signature header w/o b= tag value. */
} pdkim_signature;


/* -------------------------------------------------------------------------- */
/* Context to keep state between all operations. */
typedef struct pdkim_ctx {

#define PDKIM_MODE_SIGN   BIT(0)	/* if unset, mode==verify */
#define PDKIM_DOT_TERM	  BIT(1)	/* dot termination and unstuffing */
#define PDKIM_SEEN_CR	  BIT(2)
#define PDKIM_SEEN_LF	  BIT(3)
#define PDKIM_PAST_HDRS	  BIT(4)
#define PDKIM_SEEN_EOD	  BIT(5)
  unsigned   flags;

  /* One (signing) or several chained (verification) signatures */
  pdkim_signature *sig;

  /* One (signing) or several chained (verification) bodyhashes */
  pdkim_bodyhash *bodyhash;

  /* Callback for dns/txt query method (verification only) */
  uschar * (*dns_txt_callback)(char *);

  /* Coder's little helpers */
  gstring   *cur_header;
  uschar    *linebuf;
  int        linebuf_offset;
  int        num_headers;
  pdkim_stringlist *headers; /* Raw headers for verification         */
} pdkim_ctx;


/* -------------------------------------------------------------------------- */
/* API functions. Please see the sample code in sample/test_sign.c and
   sample/test_verify.c for documentation.
*/

#ifdef __cplusplus
extern "C" {
#endif

void	   pdkim_init         (void);

void	   pdkim_init_context (pdkim_ctx *, BOOL, uschar * (*)(char *));

DLLEXPORT
pdkim_signature *pdkim_init_sign    (pdkim_ctx *,
			       uschar *, uschar *, uschar *, uschar *,
			       const uschar **);

DLLEXPORT
pdkim_ctx *pdkim_init_verify  (uschar * (*)(char *), BOOL);

DLLEXPORT
void       pdkim_set_optional (pdkim_signature *, char *, char *,int, int,
                               long,
                               unsigned long,
                               unsigned long);

pdkim_bodyhash *pdkim_set_bodyhash(pdkim_ctx *, pdkim_signature *);

DLLEXPORT
int        pdkim_feed         (pdkim_ctx *, uschar *, int);
DLLEXPORT
int        pdkim_feed_finish  (pdkim_ctx *, pdkim_signature **, const uschar **);

DLLEXPORT
void       pdkim_free_ctx     (pdkim_ctx *);


const uschar *	pdkim_errstr(int);

uschar *	dkim_sig_to_a_tag(const pdkim_signature * sig);

#ifdef __cplusplus
}
#endif

#endif
Commit	Line	Data
80a47a2c TK	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
80a47a2c TK	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	*/
2592e6c0 JH	23	#ifndef PDKIM_H
	24	#define PDKIM_H
	25
63af6f3a JH	26	#include "../blob.h"
63af6f3a JH	27	#include "../hash.h"
80a47a2c	28
970424a5 JH	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 TK	38	/* -------------------------------------------------------------------------- */
80a47a2c TK	39	/* Length of the preallocated buffer for the "answer" from the dns/txt
4263f395 PP	40	callback function. This should match the maximum RDLENGTH from DNS. */
4263f395 PP	41	#define PDKIM_DNS_TXT_MAX_RECLEN (1 << 16)
80a47a2c TK	42
	43	/* -------------------------------------------------------------------------- */
	44	/* Function success / error codes */
	45	#define PDKIM_OK 0
	46	#define PDKIM_FAIL -1
80a47a2c TK	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
df3def24 JH	51	#define PDKIM_SIGN_PRIVKEY_WRAP -105
df3def24 JH	52	#define PDKIM_SIGN_PRIVKEY_B64D -106
80a47a2c TK	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
07eeb4df	63	#define PDKIM_VERIFY_FAIL_MESSAGE 2
135e9496 JH	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
80a47a2c TK	71
	72	/* -------------------------------------------------------------------------- */
	73	/* Some parameter values */
	74	#define PDKIM_QUERYMETHOD_DNS_TXT 0
	75
286b9d5f JH	76	/#define PDKIM_ALGO_RSA_SHA256 0 /
	77	/#define PDKIM_ALGO_RSA_SHA1 1 /
	78
80a47a2c TK	79	#define PDKIM_CANON_SIMPLE 0
	80	#define PDKIM_CANON_RELAXED 1
	81
80a47a2c TK	82	/* -------------------------------------------------------------------------- */
	83	/* Some required forward declarations, please ignore */
	84	typedef struct pdkim_stringlist pdkim_stringlist;
	85	typedef struct pdkim_str pdkim_str;
cb224393 JH	86	typedef struct sha1_context sha1_context;
	87	typedef struct sha2_context sha2_context;
	88	#define HAVE_SHA1_CONTEXT
	89	#define HAVE_SHA2_CONTEXT
80a47a2c TK	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 */
	105	typedef struct pdkim_pubkey {
35cf75e9 JH	106	const uschar * version; /* v= */
35cf75e9 JH	107	const uschar granularity; / g= */
80a47a2c	108
35cf75e9	109	const uschar * hashes; /* h= */
286b9d5f JH	110	const uschar * keytype; /* k= */
286b9d5f JH	111	const uschar * srvtype; /* s= */
e2e3255a	112	uschar notes; / n= */
80a47a2c	113
2592e6c0	114	blob key; /* p= */
80a47a2c TK	115	int testing; /* t=y */
	116	int no_subdomaining; /* t=s */
	117	} pdkim_pubkey;
	118
cf1cce5e JH	119	/* -------------------------------------------------------------------------- */
	120	/* Body-hash to be calculated */
	121	typedef 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
80a47a2c TK	134	/* -------------------------------------------------------------------------- */
	135	/* Signature as it appears in a DKIM-Signature header */
	136	typedef struct pdkim_signature {
9e70917d	137	struct pdkim_signature * next;
80a47a2c TK	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 */
80a47a2c TK	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;
80a47a2c TK	162
80a47a2c TK	163	/* (d=) The domain as given in the signature */
e2e3255a	164	uschar *domain;
80a47a2c TK	165
80a47a2c TK	166	/* (i=) The identity as given in the signature */
e2e3255a	167	uschar *identity;
80a47a2c TK	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;
80a47a2c TK	182
80a47a2c TK	183	/* (z=) */
e2e3255a	184	uschar *copiedheaders;
80a47a2c TK	185
80a47a2c TK	186	/* (b=) Raw signature data, along with its length in bytes */
dcd03763	187	blob sighash;
80a47a2c TK	188
80a47a2c TK	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.
80a47a2c TK	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;
80a47a2c TK	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
80a47a2c TK	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 */
ca9cb170 JH	258	uschar * sign_headers; /* To-be-signed header names */
ca9cb170 JH	259	uschar * rawsig_no_b_val; /* Original signature header w/o b= tag value. */
80a47a2c TK	260	} pdkim_signature;
	261
	262
	263	/* -------------------------------------------------------------------------- */
	264	/* Context to keep state between all operations. */
80a47a2c TK	265	typedef struct pdkim_ctx {
80a47a2c TK	266
e983e85a JH	267	#define PDKIM_MODE_SIGN BIT(0) /* if unset, mode==verify */
e983e85a JH	268	#define PDKIM_DOT_TERM BIT(1) /* dot termination and unstuffing */
b895f4b2 JH	269	#define PDKIM_SEEN_CR BIT(2)
b895f4b2 JH	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
80a47a2c TK	275	/* One (signing) or several chained (verification) signatures */
	276	pdkim_signature *sig;
	277
cf1cce5e JH	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 );
80a47a2c TK	283
80a47a2c TK	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 */
80a47a2c TK	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
	299	extern "C" {
	300	#endif
	301
2592e6c0 JH	302	void pdkim_init (void);
2592e6c0 JH	303
1eedc10f	304	void pdkim_init_context (pdkim_ctx , BOOL, uschar ()(char ));
9e70917d	305
80a47a2c	306	DLLEXPORT
9e70917d JH	307	pdkim_signature pdkim_init_sign (pdkim_ctx ,
	308	uschar , uschar , uschar , uschar ,
	309	const uschar **);
80a47a2c TK	310
80a47a2c TK	311	DLLEXPORT
1eedc10f	312	pdkim_ctx pdkim_init_verify (uschar ()(char ), BOOL);
80a47a2c TK	313
80a47a2c TK	314	DLLEXPORT
9e70917d	315	void pdkim_set_optional (pdkim_signature , char , char *,int, int,
f444c2c7	316	long,
80a47a2c TK	317	unsigned long,
	318	unsigned long);
	319
cf1cce5e JH	320	pdkim_bodyhash pdkim_set_bodyhash(pdkim_ctx , pdkim_signature *);
cf1cce5e JH	321
80a47a2c	322	DLLEXPORT
ef698bf6	323	int pdkim_feed (pdkim_ctx , uschar , int);
80a47a2c	324	DLLEXPORT
b9df1829	325	int pdkim_feed_finish (pdkim_ctx , pdkim_signature , const uschar *);
80a47a2c TK	326
	327	DLLEXPORT
	328	void pdkim_free_ctx (pdkim_ctx *);
	329
f7302073	330
b9df1829	331	const uschar * pdkim_errstr(int);
f7302073	332
9e70917d	333	uschar * dkim_sig_to_a_tag(const pdkim_signature * sig);
d73e45df	334
80a47a2c TK	335	#ifdef __cplusplus
	336	}
	337	#endif
2592e6c0 JH	338
2592e6c0 JH	339	#endif