-/*
- * PDKIM - a RFC4871 (DKIM) implementation
- *
- * Copyright (C) 2009 - 2012 Tom Kistner <tom@duncanthrax.net>
- * Copyright (c) 2016 - 2017 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"
-
-/* -------------------------------------------------------------------------- */
-/* 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_FAIL_BODY 1
-#define PDKIM_VERIFY_FAIL_MESSAGE 2
-#define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE 3
-#define PDKIM_VERIFY_INVALID_BUFFER_SIZE 4
-#define PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD 5
-#define PDKIM_VERIFY_INVALID_PUBKEY_IMPORT 6
-#define PDKIM_VERIFY_INVALID_SIGNATURE_ERROR 7
-#define PDKIM_VERIFY_INVALID_DKIM_VERSION 8
-
-/* -------------------------------------------------------------------------- */
-/* 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
-
-#define PDKIM_HASH_SHA256 0
-#define PDKIM_HASH_SHA1 1
-
-#define PDKIM_KEYTYPE_RSA 0
-
-/* -------------------------------------------------------------------------- */
-/* 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 {
- uschar *version; /* v= */
- uschar *granularity; /* g= */
-
-#ifdef notdef
- uschar *hashes; /* h= */
- uschar *keytype; /* k= */
-#endif
- uschar *srvtype; /* s= */
- uschar *notes; /* n= */
-
- blob key; /* p= */
- int testing; /* t=y */
- int no_subdomaining; /* t=s */
-} pdkim_pubkey;
-
-/* -------------------------------------------------------------------------- */
-/* Signature as it appears in a DKIM-Signature header */
-typedef struct pdkim_signature {
-
- /* 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
- or PDKIM_ALGO_RSA_SHA1 */
- int algo;
-
- /* (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. Singing 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;
-
- /* Pointer to the next pdkim_signature signature. NULL if signing or if
- this is the last signature. */
- void *next;
-
- /* Properties below this point are used internally only ------------- */
-
- /* Per-signature helper variables ----------------------------------- */
- hctx body_hash_ctx;
-
- unsigned long signed_body_bytes; /* How many body bytes we hashed */
- pdkim_stringlist *headers; /* Raw headers included in the sig */
- /* Signing specific ------------------------------------------------- */
- uschar * rsa_privkey; /* Private RSA 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;
-
- /* Callback for dns/txt query method (verification only) */
- int(*dns_txt_callback)(char *, char *);
-
- /* Coder's little helpers */
- uschar *cur_header;
- int cur_header_size;
- int cur_header_len;
- char *linebuf;
- int linebuf_offset;
- int num_buffered_crlf;
- 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);
-
-DLLEXPORT
-pdkim_ctx *pdkim_init_sign (char *, char *, char *, int,
- BOOL, int(*)(char *, char *));
-
-DLLEXPORT
-pdkim_ctx *pdkim_init_verify (int(*)(char *, char *), BOOL);
-
-DLLEXPORT
-int pdkim_set_optional (pdkim_ctx *, char *, char *,int, int,
- long,
- unsigned long,
- unsigned long);
-
-DLLEXPORT
-int pdkim_feed (pdkim_ctx *, char *, int);
-DLLEXPORT
-int pdkim_feed_finish (pdkim_ctx *, pdkim_signature **);
-
-DLLEXPORT
-void pdkim_free_ctx (pdkim_ctx *);
-
-
-const char * pdkim_errstr(int);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
git://git.exim.org / exim.git / blobdiff