sqlcipher/src/crypto.h

/* 
** SQLCipher
** crypto.h developed by Stephen Lombardo (Zetetic LLC) 
** sjlombardo at zetetic dot net
** http://zetetic.net
** 
** Copyright (c) 2008, ZETETIC LLC
** All rights reserved.
** 
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
**     * Redistributions of source code must retain the above copyright
**       notice, this list of conditions and the following disclaimer.
**     * 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.
**     * Neither the name of the ZETETIC LLC nor the
**       names of its contributors may be used to endorse or promote products
**       derived from this software without specific prior written permission.
** 
** THIS SOFTWARE IS PROVIDED BY ZETETIC LLC ''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 ZETETIC LLC 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.
**  
*/
/* BEGIN CRYPTO */
#ifdef SQLITE_HAS_CODEC
#ifndef CRYPTO_H
#define CRYPTO_H

#define FILE_HEADER_SZ 16

#ifndef CIPHER
#define CIPHER "aes-256-cbc"
#endif

#define CIPHER_DECRYPT 0
#define CIPHER_ENCRYPT 1

#define CIPHER_READ_CTX 0
#define CIPHER_WRITE_CTX 1
#define CIPHER_READWRITE_CTX 2

#ifndef PBKDF2_ITER
#define PBKDF2_ITER 4000
#endif

#ifndef DEFAULT_USE_HMAC
#define DEFAULT_USE_HMAC 1
#endif

#ifdef CODEC_DEBUG
#define CODEC_TRACE(X)  {printf X;fflush(stdout);}
#else
#define CODEC_TRACE(X)
#endif


/* extensions defined in pragma.c */ 
   
void sqlite3pager_get_codec(Pager *pPager, void **ctx);
int sqlite3pager_is_mj_pgno(Pager *pPager, Pgno pgno);
sqlite3_file *sqlite3Pager_get_fd(Pager *pPager);
void sqlite3pager_sqlite3PagerSetCodec(
  Pager *pPager,
  void *(*xCodec)(void*,void*,Pgno,int),
  void (*xCodecSizeChng)(void*,int,int),
  void (*xCodecFree)(void*),
  void *pCodec
);
/* end extensions defined in pragma.c */
 
/*
**  Simple shared routines for converting hex char strings to binary data
 */
static int cipher_hex2int(char c) {
  return (c>='0' && c<='9') ? (c)-'0' :
         (c>='A' && c<='F') ? (c)-'A'+10 :
         (c>='a' && c<='f') ? (c)-'a'+10 : 0;
}

static void cipher_hex2bin(const char *hex, int sz, unsigned char *out){
  int i;
  for(i = 0; i < sz; i += 2){
    out[i/2] = (cipher_hex2int(hex[i])<<4) | cipher_hex2int(hex[i+1]);
  }
}

/* extensions defined in crypto_impl.c */

typedef struct codec_ctx codec_ctx;

/* utility functions */
int sqlcipher_memcmp(const unsigned char *a0, const unsigned char *a1, int len);
int sqlcipher_pseudorandom(void *, int);
void sqlcipher_free(void *, int);

/* activation and initialization */
void sqlcipher_activate();
int sqlcipher_codec_ctx_init(codec_ctx **, Db *, Pager *, sqlite3_file *, const void *, int);
void sqlcipher_codec_ctx_free(codec_ctx **);
int sqlcipher_codec_key_derive(codec_ctx *);
int sqlcipher_codec_key_copy(codec_ctx *, int);

/* page cipher implementation */
int sqlcipher_page_cipher(codec_ctx *, int, Pgno, int, int, unsigned char *, unsigned char *);

/* context setters & getters */
void sqlcipher_codec_ctx_set_error(codec_ctx *, int);

int sqlcipher_codec_ctx_set_pass(codec_ctx *, const void *, int, int);
void sqlcipher_codec_get_pass(codec_ctx *, void **zKey, int *nKey);

int sqlcipher_codec_ctx_set_pagesize(codec_ctx *, int);
int sqlcipher_codec_ctx_get_pagesize(codec_ctx *);
int sqlcipher_codec_ctx_get_reservesize(codec_ctx *);

int sqlcipher_codec_ctx_set_kdf_iter(codec_ctx *, int, int);
void* sqlcipher_codec_ctx_get_kdf_salt(codec_ctx *ctx);

int sqlcipher_codec_ctx_set_cipher(codec_ctx *, const char *, int);

void* sqlcipher_codec_ctx_get_data(codec_ctx *);

void sqlcipher_exportFunc(sqlite3_context *, int, sqlite3_value **);

int sqlcipher_codec_ctx_set_use_hmac(codec_ctx *ctx, int use);
/* end extensions defined in crypto_impl.c */

#endif
#endif
/* END CRYPTO */