/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006
 *                2007, 2008, 2009  Free Software Foundation, Inc.
 *
 *  GRUB 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

/* Contains elements based on gcrypt-module.h and gcrypt.h.in.
   If it's changed please update this file.  */

#ifndef GRUB_CRYPTO_HEADER
#define GRUB_CRYPTO_HEADER 1

#include <grub/symbol.h>
#include <grub/types.h>
#include <grub/err.h>

typedef enum
  {
    GPG_ERR_NO_ERROR,
    GPG_ERR_BAD_MPI,
    GPG_ERR_BAD_SECKEY,
    GPG_ERR_BAD_SIGNATURE,
    GPG_ERR_CIPHER_ALGO,
    GPG_ERR_CONFLICT,
    GPG_ERR_DECRYPT_FAILED,
    GPG_ERR_DIGEST_ALGO,
    GPG_ERR_GENERAL,
    GPG_ERR_INTERNAL,
    GPG_ERR_INV_ARG,
    GPG_ERR_INV_CIPHER_MODE,
    GPG_ERR_INV_FLAG,
    GPG_ERR_INV_KEYLEN,
    GPG_ERR_INV_OBJ,
    GPG_ERR_INV_OP,
    GPG_ERR_INV_SEXP,
    GPG_ERR_INV_VALUE,
    GPG_ERR_MISSING_VALUE,
    GPG_ERR_NO_ENCRYPTION_SCHEME,
    GPG_ERR_NO_OBJ,
    GPG_ERR_NO_PRIME,
    GPG_ERR_NO_SIGNATURE_SCHEME,
    GPG_ERR_NOT_FOUND,
    GPG_ERR_NOT_IMPLEMENTED,
    GPG_ERR_NOT_SUPPORTED,
    GPG_ERROR_CFLAGS,
    GPG_ERR_PUBKEY_ALGO,
    GPG_ERR_SELFTEST_FAILED,
    GPG_ERR_TOO_SHORT,
    GPG_ERR_UNSUPPORTED,
    GPG_ERR_WEAK_KEY,
    GPG_ERR_WRONG_KEY_USAGE,
    GPG_ERR_WRONG_PUBKEY_ALGO,
    GPG_ERR_OUT_OF_MEMORY
  } gcry_err_code_t;
#define gpg_err_code_t gcry_err_code_t
#define gpg_error_t gcry_err_code_t

enum gcry_cipher_modes
  {
    GCRY_CIPHER_MODE_NONE   = 0,  /* Not yet specified. */
    GCRY_CIPHER_MODE_ECB    = 1,  /* Electronic codebook. */
    GCRY_CIPHER_MODE_CFB    = 2,  /* Cipher feedback. */
    GCRY_CIPHER_MODE_CBC    = 3,  /* Cipher block chaining. */
    GCRY_CIPHER_MODE_STREAM = 4,  /* Used with stream ciphers. */
    GCRY_CIPHER_MODE_OFB    = 5,  /* Outer feedback. */
    GCRY_CIPHER_MODE_CTR    = 6   /* Counter. */
  };

/* Type for the cipher_setkey function.  */
typedef gcry_err_code_t (*gcry_cipher_setkey_t) (void *c,
						 const unsigned char *key,
						 unsigned keylen);

/* Type for the cipher_encrypt function.  */
typedef void (*gcry_cipher_encrypt_t) (void *c,
				       unsigned char *outbuf,
				       const unsigned char *inbuf);

/* Type for the cipher_decrypt function.  */
typedef void (*gcry_cipher_decrypt_t) (void *c,
				       unsigned char *outbuf,
				       const unsigned char *inbuf);

/* Type for the cipher_stencrypt function.  */
typedef void (*gcry_cipher_stencrypt_t) (void *c,
					 unsigned char *outbuf,
					 const unsigned char *inbuf,
					 unsigned int n);

/* Type for the cipher_stdecrypt function.  */
typedef void (*gcry_cipher_stdecrypt_t) (void *c,
					 unsigned char *outbuf,
					 const unsigned char *inbuf,
					 unsigned int n);

typedef struct gcry_cipher_oid_spec
{
  const char *oid;
  int mode;
} gcry_cipher_oid_spec_t;

/* Module specification structure for ciphers.  */
typedef struct gcry_cipher_spec
{
  const char *name;
  const char **aliases;
  gcry_cipher_oid_spec_t *oids;
  grub_size_t blocksize;
  grub_size_t keylen;
  grub_size_t contextsize;
  gcry_cipher_setkey_t setkey;
  gcry_cipher_encrypt_t encrypt;
  gcry_cipher_decrypt_t decrypt;
  gcry_cipher_stencrypt_t stencrypt;
  gcry_cipher_stdecrypt_t stdecrypt;
  struct gcry_cipher_spec *next;
} gcry_cipher_spec_t;

/* Type for the md_init function.  */
typedef void (*gcry_md_init_t) (void *c);

/* Type for the md_write function.  */
typedef void (*gcry_md_write_t) (void *c, const void *buf, grub_size_t nbytes);

/* Type for the md_final function.  */
typedef void (*gcry_md_final_t) (void *c);

/* Type for the md_read function.  */
typedef unsigned char *(*gcry_md_read_t) (void *c);

typedef struct gcry_md_oid_spec
{
  const char *oidstring;
} gcry_md_oid_spec_t;

/* Module specification structure for message digests.  */
typedef struct gcry_md_spec
{
  const char *name;
  unsigned char *asnoid;
  int asnlen;
  gcry_md_oid_spec_t *oids;
  grub_size_t mdlen;
  gcry_md_init_t init;
  gcry_md_write_t write;
  gcry_md_final_t final;
  gcry_md_read_t read;
  grub_size_t contextsize; /* allocate this amount of context */
  /* Block size, needed for HMAC.  */
  grub_size_t blocksize;
  struct gcry_md_spec *next;
} gcry_md_spec_t;

struct grub_crypto_cipher_handle
{
  const struct gcry_cipher_spec *cipher;
  char ctx[0];
};

typedef struct grub_crypto_cipher_handle *grub_crypto_cipher_handle_t;

struct grub_crypto_hmac_handle;

const gcry_cipher_spec_t *
grub_crypto_lookup_cipher_by_name (const char *name);

grub_crypto_cipher_handle_t
grub_crypto_cipher_open (const struct gcry_cipher_spec *cipher);

gcry_err_code_t
grub_crypto_cipher_set_key (grub_crypto_cipher_handle_t cipher,
			    const unsigned char *key,
			    unsigned keylen);

void
grub_crypto_cipher_close (grub_crypto_cipher_handle_t cipher);

void
grub_crypto_xor (void *out, const void *in1, const void *in2, grub_size_t size);

gcry_err_code_t
grub_crypto_ecb_decrypt (grub_crypto_cipher_handle_t cipher,
			 void *out, void *in, grub_size_t size);

gcry_err_code_t
grub_crypto_ecb_encrypt (grub_crypto_cipher_handle_t cipher,
			 void *out, void *in, grub_size_t size);
gcry_err_code_t
grub_crypto_cbc_encrypt (grub_crypto_cipher_handle_t cipher,
			 void *out, void *in, grub_size_t size,
			 void *iv_in);
gcry_err_code_t
grub_crypto_cbc_decrypt (grub_crypto_cipher_handle_t cipher,
			 void *out, void *in, grub_size_t size,
			 void *iv);
void
grub_cipher_register (gcry_cipher_spec_t *cipher);
void
grub_cipher_unregister (gcry_cipher_spec_t *cipher);
void
grub_md_register (gcry_md_spec_t *digest);
void
grub_md_unregister (gcry_md_spec_t *cipher);
void
grub_crypto_hash (const gcry_md_spec_t *hash, void *out, const void *in,
		  grub_size_t inlen);
const gcry_md_spec_t *
grub_crypto_lookup_md_by_name (const char *name);

grub_err_t
grub_crypto_gcry_error (gcry_err_code_t in);

void grub_burn_stack (grub_size_t size);

struct grub_crypto_hmac_handle *
grub_crypto_hmac_init (const struct gcry_md_spec *md,
		       const void *key, grub_size_t keylen);
void
grub_crypto_hmac_write (struct grub_crypto_hmac_handle *hnd, void *data,
			grub_size_t datalen);
gcry_err_code_t
grub_crypto_hmac_fini (struct grub_crypto_hmac_handle *hnd, void *out);

gcry_err_code_t
grub_crypto_hmac_buffer (const struct gcry_md_spec *md,
			 const void *key, grub_size_t keylen,
			 void *data, grub_size_t datalen, void *out);

extern gcry_md_spec_t _gcry_digest_spec_md5;
extern gcry_md_spec_t _gcry_digest_spec_sha1;
extern gcry_md_spec_t _gcry_digest_spec_sha256;
extern gcry_md_spec_t _gcry_digest_spec_sha512;
#define GRUB_MD_MD5 ((const gcry_md_spec_t *) &_gcry_digest_spec_md5)
#define GRUB_MD_SHA1 ((const gcry_md_spec_t *) &_gcry_digest_spec_sha1)
#define GRUB_MD_SHA256 ((const gcry_md_spec_t *) &_gcry_digest_spec_sha256)
#define GRUB_MD_SHA512 ((const gcry_md_spec_t *) &_gcry_digest_spec_sha512)

/* Implement PKCS#5 PBKDF2 as per RFC 2898.  The PRF to use is HMAC variant
   of digest supplied by MD.  Inputs are the password P of length PLEN,
   the salt S of length SLEN, the iteration counter C (> 0), and the
   desired derived output length DKLEN.  Output buffer is DK which
   must have room for at least DKLEN octets.  The output buffer will
   be filled with the derived data.  */
gcry_err_code_t
grub_crypto_pbkdf2 (const struct gcry_md_spec *md,
		    const grub_uint8_t *P, grub_size_t Plen,
		    const grub_uint8_t *S, grub_size_t Slen,
		    unsigned int c,
		    grub_uint8_t *DK, grub_size_t dkLen);

int
grub_crypto_memcmp (const void *a, const void *b, grub_size_t n);

int
grub_password_get (char buf[], unsigned buf_size);

/* For indistinguishibility.  */
#define GRUB_ACCESS_DENIED grub_error (GRUB_ERR_ACCESS_DENIED, "Access denied.")

extern void (*grub_crypto_autoload_hook) (const char *name);

#endif
