/*
 * pgp.h
 *	  OpenPGP implementation.
 *
 * Copyright (c) 2005 Marko Kreen
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in the
 *	  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.	IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $PostgreSQL: pgsql/contrib/pgcrypto/pgp.h,v 1.2 2005/07/18 17:09:01 tgl Exp $
 */

enum
{
	PGP_S2K_SIMPLE = 0,
	PGP_S2K_SALTED = 1,
	PGP_S2K_ISALTED = 3
} PGP_S2K_TYPE;

enum
{
	PGP_PKT_RESERVED = 0,
	PGP_PKT_PUBENCRYPTED_SESSKEY = 1,
	PGP_PKT_SIGNATURE = 2,
	PGP_PKT_SYMENCRYPTED_SESSKEY = 3,
	PGP_PKT_SECRET_KEY = 5,
	PGP_PKT_PUBLIC_KEY = 6,
	PGP_PKT_SECRET_SUBKEY = 7,
	PGP_PKT_COMPRESSED_DATA = 8,
	PGP_PKT_SYMENCRYPTED_DATA = 9,
	PGP_PKT_MARKER = 10,
	PGP_PKT_LITERAL_DATA = 11,
	PGP_PKT_TRUST = 12,
	PGP_PKT_USER_ID = 13,
	PGP_PKT_PUBLIC_SUBKEY = 14,
	PGP_PKT_USER_ATTR = 17,
	PGP_PKT_SYMENCRYPTED_DATA_MDC = 18,
	PGP_PKT_MDC = 19,
	PGP_PKT_PRIV_61 = 61  /* occurs in gpg secring */
} PGP_PKT_TYPE;

enum
{
	PGP_PUB_RSA_ENCRYPT_SIGN = 1,
	PGP_PUB_RSA_ENCRYPT = 2,
	PGP_PUB_RSA_SIGN = 3,
	PGP_PUB_ELG_ENCRYPT = 16,
	PGP_PUB_DSA_SIGN = 17
} PGP_PUB_ALGO_TYPE;

enum
{
	PGP_SYM_PLAIN = 0,			/* ?? */
	PGP_SYM_IDEA = 1,			/* obsolete, PGP 2.6 compat */
	PGP_SYM_DES3 = 2,			/* must */
	PGP_SYM_CAST5 = 3,			/* should */
	PGP_SYM_BLOWFISH = 4,
	PGP_SYM_SAFER_SK128 = 5,	/* obsolete */
	PGP_SYM_DES_SK = 6,			/* obsolete */
	PGP_SYM_AES_128 = 7,		/* should */
	PGP_SYM_AES_192 = 8,
	PGP_SYM_AES_256 = 9,
	PGP_SYM_TWOFISH = 10
} PGP_SYMENC_TYPE;

enum
{
	PGP_COMPR_NONE = 0,			/* must */
	PGP_COMPR_ZIP = 1,			/* should */
	PGP_COMPR_ZLIB = 2,
	PGP_COMPR_BZIP2 = 3
} PGP_COMPR_TYPE;

enum
{
	PGP_DIGEST_MD5 = 1,			/* should, deprecated  */
	PGP_DIGEST_SHA1 = 2,			/* must */
	PGP_DIGEST_RIPEMD160 = 3,
	PGP_DIGEST_XSHA = 4,			/* obsolete */
	PGP_DIGEST_MD2 = 5,			/* obsolete */
	PGP_DIGEST_TIGER192 = 6,		/* obsolete */
	PGP_DIGEST_HAVAL5_160 = 7,	/* obsolete */
	PGP_DIGEST_SHA256 = 8,
	PGP_DIGEST_SHA384 = 9,
	PGP_DIGEST_SHA512 = 10
} PGP_DIGEST_TYPE;

#define PGP_MAX_KEY    (256/8)
#define PGP_MAX_BLOCK  (256/8)
#define PGP_MAX_DIGEST (512/8)
#define PGP_S2K_SALT   8

typedef struct PGP_MPI PGP_MPI;
typedef struct PGP_PubKey PGP_PubKey;
typedef struct PGP_Context PGP_Context;
typedef struct PGP_S2K PGP_S2K;

struct PGP_S2K {
	uint8 mode;
	uint8 digest_algo;
	uint8 salt[8];
	uint8 iter;
	/* calculated: */
	uint8 key[PGP_MAX_KEY];
	uint8 key_len;
};


struct PGP_Context
{
	/*
	 * parameters
	 */
	PGP_S2K		s2k;
	int			s2k_mode;
	int			s2k_digest_algo;
	int			s2k_cipher_algo;
	int			cipher_algo;
	int			compress_algo;
	int			compress_level;
	int			disable_mdc;
	int			use_sess_key;
	int			text_mode;
	int			convert_crlf;
	int			unicode_mode;

	/*
	 * internal variables
	 */
	int			mdc_checked;
	int			corrupt_prefix;
	int			in_mdc_pkt;
	int			use_mdcbuf_filter;
	PX_MD	   *mdc_ctx;
	
	PGP_PubKey	*pub_key; /* ctx owns it*/
	const uint8 *sym_key; /* ctx does not own it */
	int			sym_key_len;

	/*
	 * read or generated data
	 */
	uint8		sess_key[PGP_MAX_KEY];
	unsigned	sess_key_len;
};

struct PGP_MPI {
	uint8 *data;
	int bits;
	int bytes;
};

struct PGP_PubKey {
	uint8 ver;
	uint8 time[4];
	uint8 algo;
	/* public */
	PGP_MPI *elg_p;
	PGP_MPI *elg_g;
	PGP_MPI *elg_y;
	/* secret */
	PGP_MPI *elg_x;

	uint8 key_id[8];
};

int			pgp_init(PGP_Context ** ctx);
int			pgp_encrypt(PGP_Context * ctx, MBuf * src, MBuf * dst);
int			pgp_decrypt(PGP_Context * ctx, MBuf * src, MBuf * dst);
int			pgp_free(PGP_Context * ctx);

int			pgp_get_digest_code(const char *name);
int			pgp_get_cipher_code(const char *name);
const char *pgp_get_digest_name(int code);
const char *pgp_get_cipher_name(int code);

int			pgp_set_cipher_algo(PGP_Context * ctx, const char *name);
int			pgp_set_s2k_mode(PGP_Context * ctx, int type);
int			pgp_set_s2k_cipher_algo(PGP_Context * ctx, const char *name);
int			pgp_set_s2k_digest_algo(PGP_Context * ctx, const char *name);
int			pgp_set_convert_crlf(PGP_Context * ctx, int doit);
int			pgp_disable_mdc(PGP_Context * ctx, int disable);
int			pgp_set_sess_key(PGP_Context * ctx, int use);
int			pgp_set_compress_algo(PGP_Context * ctx, int algo);
int			pgp_set_compress_level(PGP_Context * ctx, int level);
int			pgp_set_text_mode(PGP_Context * ctx, int mode);
int			pgp_set_unicode_mode(PGP_Context * ctx, int mode);
int			pgp_get_unicode_mode(PGP_Context * ctx);

int			pgp_set_symkey(PGP_Context *ctx, const uint8 *key, int klen);
int			pgp_set_pubkey(PGP_Context *ctx, MBuf *keypkt,
						const uint8 *key, int klen, int pubtype);

int			pgp_get_keyid(MBuf *pgp_data, char *dst);

/* internal functions */

int			pgp_load_digest(int c, PX_MD ** res);
int			pgp_load_cipher(int c, PX_Cipher ** res);
int			pgp_get_cipher_key_size(int c);
int			pgp_get_cipher_block_size(int c);

int pgp_s2k_fill(PGP_S2K *s2k, int mode, int digest_algo);
int pgp_s2k_read(PullFilter *src, PGP_S2K *s2k);
int pgp_s2k_process(PGP_S2K *s2k, int cipher, const uint8 *key, int klen);

typedef struct PGP_CFB PGP_CFB;
int pgp_cfb_create(PGP_CFB **ctx_p, int algo,
		const uint8 *key, int key_len, int recync, uint8 *iv);
void pgp_cfb_free(PGP_CFB *ctx);
int pgp_cfb_encrypt(PGP_CFB *ctx, const uint8 *data, int len, uint8 *dst);
int pgp_cfb_decrypt(PGP_CFB *ctx, const uint8 *data, int len, uint8 *dst);

int			pgp_armor_encode(const uint8 *src, unsigned len, uint8 *dst);
int			pgp_armor_decode(const uint8 *src, unsigned len, uint8 *dst);
unsigned	pgp_armor_enc_len(unsigned len);
unsigned	pgp_armor_dec_len(unsigned len);

int pgp_compress_filter(PushFilter **res, PGP_Context *ctx, PushFilter *dst);
int pgp_decompress_filter(PullFilter **res, PGP_Context *ctx, PullFilter *src);

int pgp_key_alloc(PGP_PubKey **pk_p);
void pgp_key_free(PGP_PubKey *pk);
int _pgp_read_public_key(PullFilter *pkt, PGP_PubKey *pk);

int pgp_parse_pubenc_sesskey(PGP_Context *ctx, PullFilter *pkt);
int pgp_create_pkt_reader(PullFilter **pf_p, PullFilter *src, int len,
		        int pkttype, PGP_Context *ctx);
int pgp_parse_pkt_hdr(PullFilter * src, uint8 *tag, int *len_p,
		        int allow_ctx);

int pgp_skip_packet(PullFilter *pkt);
int pgp_expect_packet_end(PullFilter *pkt);

int pgp_write_pubenc_sesskey(PGP_Context *ctx, PushFilter *dst);
int pgp_create_pkt_writer(PushFilter *dst, int tag, PushFilter **res_p);

int pgp_mpi_alloc(int bits, PGP_MPI **mpi);
int pgp_mpi_create(uint8 *data, int bits, PGP_MPI **mpi);
int pgp_mpi_free(PGP_MPI *mpi);
int pgp_mpi_read(PullFilter *src, PGP_MPI **mpi);
int pgp_mpi_write(PushFilter *dst, PGP_MPI *n);
int pgp_mpi_hash(PX_MD *md, PGP_MPI *n);
unsigned pgp_mpi_cksum(unsigned cksum, PGP_MPI *n);

int pgp_elgamal_encrypt(PGP_PubKey *pk, PGP_MPI *m,
						PGP_MPI **c1, PGP_MPI **c2);
int pgp_elgamal_decrypt(PGP_PubKey *pk, PGP_MPI *c1, PGP_MPI *c2,
						PGP_MPI **m);

extern struct PullFilterOps pgp_decrypt_filter;

