[cygwin-apps/setup.git] / gpg-packet.h

/*
 * Copyright (c) 2008, Dave Korn.
 *
 *     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.
 *
 *     A copy of the GNU General Public License can be found at
 *     http://www.gnu.org/
 *
 *   This module contains support utilities to assist in reading and
 * parsing RFC4880-compliant OpenPGP format signature and key files,
 * and related constant definitions.
 *
 *
 * Written by Dave Korn <dave.korn.cygwin@gmail.com>
 *
 */

#ifndef SETUP_GPG_PACKET_H
#define SETUP_GPG_PACKET_H


/*

4.3.  Packet Tags

   The packet tag denotes what type of packet the body holds.  Note that
   old format headers can only have tags less than 16, whereas new
   format headers can have tags as great as 63.  The defined tags (in
   decimal) are as follows:

       0        -- Reserved - a packet tag MUST NOT have this value
       1        -- Public-Key Encrypted Session Key Packet
       2        -- Signature Packet
       3        -- Symmetric-Key Encrypted Session Key Packet
       4        -- One-Pass Signature Packet
       5        -- Secret-Key Packet
       6        -- Public-Key Packet
       7        -- Secret-Subkey Packet
       8        -- Compressed Data Packet
       9        -- Symmetrically Encrypted Data Packet
       10       -- Marker Packet
       11       -- Literal Data Packet
       12       -- Trust Packet
       13       -- User ID Packet
       14       -- Public-Subkey Packet
       17       -- User Attribute Packet
       18       -- Sym. Encrypted and Integrity Protected Data Packet
       19       -- Modification Detection Code Packet
       60 to 63 -- Private or Experimental Values


*/

#define RFC4880_PT_SIGNATURE  2
#define RFC4880_PT_PUBLIC_KEY 6


/*

9.1.  Public-Key Algorithms

      ID           Algorithm
      --           ---------
      1          - RSA (Encrypt or Sign) [HAC]
      2          - RSA Encrypt-Only [HAC]
      3          - RSA Sign-Only [HAC]
      16         - Elgamal (Encrypt-Only) [ELGAMAL] [HAC]
      17         - DSA (Digital Signature Algorithm) [FIPS186] [HAC]
      18         - Reserved for Elliptic Curve
      19         - Reserved for ECDSA
      20         - Reserved (formerly Elgamal Encrypt or Sign)
      21         - Reserved for Diffie-Hellman (X9.42,
                   as defined for IETF-S/MIME)
      100 to 110 - Private/Experimental algorithm

   Implementations MUST implement DSA for signatures, and Elgamal for
   encryption.  Implementations SHOULD implement RSA keys (1).  RSA
   Encrypt-Only (2) and RSA Sign-Only are deprecated and SHOULD NOT be
   generated, but may be interpreted.  See Section 13.5.  See Section
   13.8 for notes on Elliptic Curve (18), ECDSA (19), Elgamal Encrypt or
   Sign (20), and X9.42 (21).  Implementations MAY implement any other
   algorithm.

*/

#define RFC4880_PK_RSA        1
#define RFC4880_PK_RSA_EO     2
#define RFC4880_PK_RSA_SO     3
#define RFC4880_PK_ELGAMAL    16
#define RFC4880_PK_DSA        17


/*
5.2.1.  Signature Types

   There are a number of possible meanings for a signature, which are
   indicated in a signature type octet in any given signature.  Please
   note that the vagueness of these meanings is not a flaw, but a
   feature of the system.  Because OpenPGP places final authority for
   validity upon the receiver of a signature, it may be that one
   signer's casual act might be more rigorous than some other
   authority's positive act.  See Section 5.2.4, "Computing Signatures",
   for detailed information on how to compute and verify signatures of
   each type.

   These meanings are as follows:

   0x00: Signature of a binary document.
       This means the signer owns it, created it, or certifies that it
       has not been modified.

   0x01: Signature of a canonical text document.
       This means the signer owns it, created it, or certifies that it
       has not been modified.  The signature is calculated over the text
       data with its line endings converted to <CR><LF>.

   0x02: Standalone signature.
   0x10: Generic certification of a User ID and Public-Key packet.
   0x11: Persona certification of a User ID and Public-Key packet.
   0x12: Casual certification of a User ID and Public-Key packet.
   0x13: Positive certification of a User ID and Public-Key packet.
   0x18: Subkey Binding Signature
   0x19: Primary Key Binding Signature
   0x1F: Signature directly on a key
   0x20: Key revocation signature
   0x28: Subkey revocation signature
   0x30: Certification revocation signature
   0x40: Timestamp signature.
   0x50: Third-Party Confirmation signature.

*/
#define RFC4880_ST_BINARY     0
#define RFC4880_ST_CANONTEXT  1


/*
9.4.  Hash Algorithms

      ID           Algorithm                             Text Name
      --           ---------                             ---------
      1          - MD5 [HAC]                             "MD5"
      2          - SHA-1 [FIPS180]                       "SHA1"
      3          - RIPE-MD/160 [HAC]                     "RIPEMD160"
      4          - Reserved
      5          - Reserved
      6          - Reserved
      7          - Reserved
      8          - SHA256 [FIPS180]                      "SHA256"
      9          - SHA384 [FIPS180]                      "SHA384"
      10         - SHA512 [FIPS180]                      "SHA512"
      11         - SHA224 [FIPS180]                      "SHA224"
      100 to 110 - Private/Experimental algorithm

   Implementations MUST implement SHA-1.  Implementations MAY implement
   other algorithms.  MD5 is deprecated.
*/

#define RFC4880_HC_MD5        1
#define RFC4880_HC_SHA1       2
#define RFC4880_HC_RIPEMD160  3
#define RFC4880_HC_SHA256     8
#define RFC4880_HC_SHA384     9
#define RFC4880_HC_SHA512     10
#define RFC4880_HC_SHA224     11


// This enum is returned by the callback function that is
// invoked by the packet walker for every packet walked;
// it tells it to continue or go home early.
enum pkt_cb_resp
{
  pktCONTINUE, 
  pktHALT
};

// Forward declaration of context data struct.
struct packet_walker;

// The type of callback function that can be called for every
// packet walked.
typedef enum pkt_cb_resp (*packet_walk_cb)
	(struct packet_walker *wlk, unsigned char tag, size_t packetsize,
	size_t hdrpos);

// This struct is used to wrap the context data for a packet walk.
struct packet_walker
{
  io_stream *pfile;
  packet_walk_cb func;
  HWND owner;
  void *userdata;
  size_t startpos;
  size_t size_to_walk;
  bool is_subpackets;
};

/* 

3.  Data Element Formats

   This section describes the data elements used by OpenPGP.

3.1.  Scalar Numbers

   Scalar numbers are unsigned and are always stored in big-endian
   format.  Using n[k] to refer to the kth octet being interpreted, the
   value of a two-octet scalar is ((n[0] << 8) + n[1]).  The value of a
   four-octet scalar is ((n[0] << 24) + (n[1] << 16) + (n[2] << 8) +
   n[3]).

*/

/*  Extract a byte/char from file.  Returns EOF if none left. */
static inline int
pkt_getch (io_stream *file)
{
  unsigned char ch;
  if (file->read (&ch, 1) != 1)
    return EOF;
  return ch;
}

/*  Extract a 16-bit BE int from file.  Returns EOF if none left. */
static inline long
pkt_getword (io_stream *file)
{
  unsigned char ch[2];
  if (file->read (&ch, 2) != 2)
    return EOF;
  return (ch[0] << 8) | ch[1];
}

/*  Extract a 32-bit BE int from file.  Returns EOF if none left.
  Determining the difference between EOF and 0xffffffff is left
  as an exercise for the caller - in the contexts where we need
  a dword (packet len, timestamp, signer id), we wouldn't expect
  to find ~0 anyway and so may safely leave it as a false positive.
  Note that this would cause problems with setup.ini files signed
  in the last second before the epoch rolls over.  Workaround: WDDTT.  */
static inline long
pkt_getdword (io_stream *file)
{
  unsigned char ch[4];
  if (file->read (&ch, 4) != 4)
    return EOF;
  return (ch[0] << 24) | (ch[1] << 16) | (ch[2] << 8) | ch[3];
}

/*  Extract an RFC4880 variable-length length field from file.
   Returns EOF if none left or negative if invalid format. */
extern long pkt_getlen (io_stream *file);

/*  Extract an RFC4880 MPI field from file.
   Returns EOF if none left or negative if invalid format. */
extern int pkt_get_mpi (gcry_mpi_t *mpiptr, io_stream *file);

/*  Converts from RFC4880 hash codes (9.4 above) to the hash 
   algorithm constants used in libgcrypt and the rest of the code.  */
extern char pkt_convert_hashcode (char rfc_hash);

/*  Two functions for walking the (sub)packets found within a
   seleected region of an io_stream, calling a hook for each one.  */
extern void *pkt_walk_packets (io_stream *packet_file, packet_walk_cb func, 
	HWND owner, size_t startpos, size_t size_to_walk, void *userdata);

extern void *pkt_walk_subpackets (io_stream *packet_file, packet_walk_cb func,
	HWND owner, size_t startpos, size_t size_to_walk, void *userdata);


#endif /* SETUP_GPG_PACKET_H */
Commit	Line	Data
dbfe3c19 DK	1	/*
	2	* Copyright (c) 2008, Dave Korn.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* A copy of the GNU General Public License can be found at
	10	* http://www.gnu.org/
	11	*
	12	* This module contains support utilities to assist in reading and
	13	* parsing RFC4880-compliant OpenPGP format signature and key files,
	14	* and related constant definitions.
	15	*
	16	*
	17	* Written by Dave Korn <dave.korn.cygwin@gmail.com>
	18	*
	19	*/
	20
	21	#ifndef SETUP_GPG_PACKET_H
	22	#define SETUP_GPG_PACKET_H
	23
	24
	25	/*
	26
	27	4.3. Packet Tags
	28
	29	The packet tag denotes what type of packet the body holds. Note that
	30	old format headers can only have tags less than 16, whereas new
	31	format headers can have tags as great as 63. The defined tags (in
	32	decimal) are as follows:
	33
	34	0 -- Reserved - a packet tag MUST NOT have this value
	35	1 -- Public-Key Encrypted Session Key Packet
	36	2 -- Signature Packet
	37	3 -- Symmetric-Key Encrypted Session Key Packet
	38	4 -- One-Pass Signature Packet
	39	5 -- Secret-Key Packet
	40	6 -- Public-Key Packet
	41	7 -- Secret-Subkey Packet
	42	8 -- Compressed Data Packet
	43	9 -- Symmetrically Encrypted Data Packet
	44	10 -- Marker Packet
	45	11 -- Literal Data Packet
	46	12 -- Trust Packet
	47	13 -- User ID Packet
	48	14 -- Public-Subkey Packet
	49	17 -- User Attribute Packet
	50	18 -- Sym. Encrypted and Integrity Protected Data Packet
	51	19 -- Modification Detection Code Packet
	52	60 to 63 -- Private or Experimental Values
	53
	54
	55	*/
	56
	57	#define RFC4880_PT_SIGNATURE 2
	58	#define RFC4880_PT_PUBLIC_KEY 6
	59
	60
	61	/*
	62
	63	9.1. Public-Key Algorithms
	64
65	ID Algorithm
66	-- ---------
67	1 - RSA (Encrypt or Sign) [HAC]
68	2 - RSA Encrypt-Only [HAC]
69	3 - RSA Sign-Only [HAC]
70	16 - Elgamal (Encrypt-Only) [ELGAMAL] [HAC]
71	17 - DSA (Digital Signature Algorithm) [FIPS186] [HAC]
72	18 - Reserved for Elliptic Curve
73	19 - Reserved for ECDSA
74	20 - Reserved (formerly Elgamal Encrypt or Sign)
75	21 - Reserved for Diffie-Hellman (X9.42,
76	as defined for IETF-S/MIME)
77	100 to 110 - Private/Experimental algorithm
78
79	Implementations MUST implement DSA for signatures, and Elgamal for
80	encryption. Implementations SHOULD implement RSA keys (1). RSA
81	Encrypt-Only (2) and RSA Sign-Only are deprecated and SHOULD NOT be
82	generated, but may be interpreted. See Section 13.5. See Section
83	13.8 for notes on Elliptic Curve (18), ECDSA (19), Elgamal Encrypt or
84	Sign (20), and X9.42 (21). Implementations MAY implement any other
85	algorithm.
86
87	*/
88
89	#define RFC4880_PK_RSA 1
90	#define RFC4880_PK_RSA_EO 2
91	#define RFC4880_PK_RSA_SO 3
92	#define RFC4880_PK_ELGAMAL 16
93	#define RFC4880_PK_DSA 17
94
95
96	/*
97	5.2.1. Signature Types
98
99	There are a number of possible meanings for a signature, which are
100	indicated in a signature type octet in any given signature. Please
101	note that the vagueness of these meanings is not a flaw, but a
102	feature of the system. Because OpenPGP places final authority for
103	validity upon the receiver of a signature, it may be that one
104	signer's casual act might be more rigorous than some other
105	authority's positive act. See Section 5.2.4, "Computing Signatures",
106	for detailed information on how to compute and verify signatures of
107	each type.
108
109	These meanings are as follows:
110
111	0x00: Signature of a binary document.
112	This means the signer owns it, created it, or certifies that it
113	has not been modified.
114
115	0x01: Signature of a canonical text document.
116	This means the signer owns it, created it, or certifies that it
117	has not been modified. The signature is calculated over the text
118	data with its line endings converted to <CR><LF>.
119
120	0x02: Standalone signature.
121	0x10: Generic certification of a User ID and Public-Key packet.
122	0x11: Persona certification of a User ID and Public-Key packet.
123	0x12: Casual certification of a User ID and Public-Key packet.
124	0x13: Positive certification of a User ID and Public-Key packet.
125	0x18: Subkey Binding Signature
126	0x19: Primary Key Binding Signature
127	0x1F: Signature directly on a key
128	0x20: Key revocation signature
129	0x28: Subkey revocation signature
130	0x30: Certification revocation signature
131	0x40: Timestamp signature.
132	0x50: Third-Party Confirmation signature.
133
134	*/
135	#define RFC4880_ST_BINARY 0
136	#define RFC4880_ST_CANONTEXT 1
137
138
139	/*
140	9.4. Hash Algorithms
141
142	ID Algorithm Text Name
143	-- --------- ---------
144	1 - MD5 [HAC] "MD5"
145	2 - SHA-1 [FIPS180] "SHA1"
146	3 - RIPE-MD/160 [HAC] "RIPEMD160"
147	4 - Reserved
148	5 - Reserved
149	6 - Reserved
150	7 - Reserved
151	8 - SHA256 [FIPS180] "SHA256"
152	9 - SHA384 [FIPS180] "SHA384"
153	10 - SHA512 [FIPS180] "SHA512"
154	11 - SHA224 [FIPS180] "SHA224"
155	100 to 110 - Private/Experimental algorithm
156
157	Implementations MUST implement SHA-1. Implementations MAY implement
158	other algorithms. MD5 is deprecated.
159	*/
160
161	#define RFC4880_HC_MD5 1
162	#define RFC4880_HC_SHA1 2
163	#define RFC4880_HC_RIPEMD160 3
164	#define RFC4880_HC_SHA256 8
165	#define RFC4880_HC_SHA384 9
166	#define RFC4880_HC_SHA512 10
167	#define RFC4880_HC_SHA224 11
168
169
170	// This enum is returned by the callback function that is
171	// invoked by the packet walker for every packet walked;
172	// it tells it to continue or go home early.
173	enum pkt_cb_resp
174	{
175	pktCONTINUE,
176	pktHALT
177	};
178
179	// Forward declaration of context data struct.
180	struct packet_walker;
181
182	// The type of callback function that can be called for every
183	// packet walked.
184	typedef enum pkt_cb_resp (*packet_walk_cb)
185	(struct packet_walker *wlk, unsigned char tag, size_t packetsize,
186	size_t hdrpos);
187
188	// This struct is used to wrap the context data for a packet walk.
189	struct packet_walker
190	{
191	io_stream *pfile;
192	packet_walk_cb func;
193	HWND owner;
194	void *userdata;
195	size_t startpos;
196	size_t size_to_walk;
197	bool is_subpackets;
198	};
199
200	/*
201
202	3. Data Element Formats
203
204	This section describes the data elements used by OpenPGP.
205
206	3.1. Scalar Numbers
207
208	Scalar numbers are unsigned and are always stored in big-endian
209	format. Using n[k] to refer to the kth octet being interpreted, the
210	value of a two-octet scalar is ((n[0] << 8) + n[1]). The value of a
211	four-octet scalar is ((n[0] << 24) + (n[1] << 16) + (n[2] << 8) +
212	n[3]).
213
214	*/
215
216	/* Extract a byte/char from file. Returns EOF if none left. */
217	static inline int
218	pkt_getch (io_stream *file)
219	{
220	unsigned char ch;
221	if (file->read (&ch, 1) != 1)
222	return EOF;
223	return ch;
224	}
225
226	/* Extract a 16-bit BE int from file. Returns EOF if none left. */
227	static inline long
228	pkt_getword (io_stream *file)
229	{
230	unsigned char ch[2];
231	if (file->read (&ch, 2) != 2)
232	return EOF;
233	return (ch[0] << 8) \| ch[1];
234	}
235
236	/* Extract a 32-bit BE int from file. Returns EOF if none left.
237	Determining the difference between EOF and 0xffffffff is left
238	as an exercise for the caller - in the contexts where we need
239	a dword (packet len, timestamp, signer id), we wouldn't expect
240	to find ~0 anyway and so may safely leave it as a false positive.
241	Note that this would cause problems with setup.ini files signed
242	in the last second before the epoch rolls over. Workaround: WDDTT. */
243	static inline long
244	pkt_getdword (io_stream *file)
245	{
246	unsigned char ch[4];
247	if (file->read (&ch, 4) != 4)
248	return EOF;
249	return (ch[0] << 24) \| (ch[1] << 16) \| (ch[2] << 8) \| ch[3];
250	}
251
252	/* Extract an RFC4880 variable-length length field from file.
253	Returns EOF if none left or negative if invalid format. */
254	extern long pkt_getlen (io_stream *file);
255
256	/* Extract an RFC4880 MPI field from file.
257	Returns EOF if none left or negative if invalid format. */
258	extern int pkt_get_mpi (gcry_mpi_t mpiptr, io_stream file);
259
260	/* Converts from RFC4880 hash codes (9.4 above) to the hash
261	algorithm constants used in libgcrypt and the rest of the code. */
262	extern char pkt_convert_hashcode (char rfc_hash);
263
264	/* Two functions for walking the (sub)packets found within a
265	seleected region of an io_stream, calling a hook for each one. */
266	extern void pkt_walk_packets (io_stream packet_file, packet_walk_cb func,
267	HWND owner, size_t startpos, size_t size_to_walk, void *userdata);
268
269	extern void pkt_walk_subpackets (io_stream packet_file, packet_walk_cb func,
270	HWND owner, size_t startpos, size_t size_to_walk, void *userdata);
271
272
273
274	#endif /* SETUP_GPG_PACKET_H */