diff options
Diffstat (limited to 'Plugins/DbSqliteWx/codec.c')
| -rw-r--r-- | Plugins/DbSqliteWx/codec.c | 771 |
1 files changed, 771 insertions, 0 deletions
diff --git a/Plugins/DbSqliteWx/codec.c b/Plugins/DbSqliteWx/codec.c new file mode 100644 index 0000000..9a8ccd6 --- /dev/null +++ b/Plugins/DbSqliteWx/codec.c @@ -0,0 +1,771 @@ +/*
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+// Name: codec.cpp
+// Purpose:
+// Author: Ulrich Telle
+// Modified by:
+// Created: 2006-12-06
+// RCS-ID: $$
+// Copyright: (c) Ulrich Telle
+// Licence: wxWindows licence + RSA Data Security license
+///////////////////////////////////////////////////////////////////////////////
+
+/// \file codec.cpp Implementation of MD5, RC4 and AES algorithms
+*/
+/*
+ **********************************************************************
+ ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. **
+ ** **
+ ** License to copy and use this software is granted provided that **
+ ** it is identified as the "RSA Data Security, Inc. MD5 Message **
+ ** Digest Algorithm" in all material mentioning or referencing this **
+ ** software or this function. **
+ ** **
+ ** License is also granted to make and use derivative works **
+ ** provided that such works are identified as "derived from the RSA **
+ ** Data Security, Inc. MD5 Message Digest Algorithm" in all **
+ ** material mentioning or referencing the derived work. **
+ ** **
+ ** RSA Data Security, Inc. makes no representations concerning **
+ ** either the merchantability of this software or the suitability **
+ ** of this software for any particular purpose. It is provided "as **
+ ** is" without express or implied warranty of any kind. **
+ ** **
+ ** These notices must be retained in any copies of any part of this **
+ ** documentation and/or software. **
+ **********************************************************************
+ */
+
+#include "codec.h"
+
+#ifndef SQLITE_USER_AUTHENTICATION
+#if CODEC_TYPE == CODEC_TYPE_AES256
+#include "sha2.h"
+#include "sha2.c"
+#endif
+#endif
+
+/*
+// ----------------
+// MD5 by RSA
+// ----------------
+
+// C headers for MD5
+*/
+#include <sys/types.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MD5_HASHBYTES 16
+
+/*
+/// Structure representing an MD5 context while ecrypting. (For internal use only)
+*/
+typedef struct MD5Context
+{
+ unsigned int buf[4];
+ unsigned int bits[2];
+ unsigned char in[64];
+} MD5_CTX;
+
+static void MD5Init(MD5_CTX *context);
+static void MD5Update(MD5_CTX *context, unsigned char *buf, unsigned len);
+static void MD5Final(unsigned char digest[MD5_HASHBYTES], MD5_CTX *context);
+static void MD5Transform(unsigned int buf[4], unsigned int in[16]);
+
+static void byteReverse(unsigned char *buf, unsigned longs);
+
+/*
+ * Note: this code is harmless on little-endian machines.
+ */
+static void byteReverse(unsigned char *buf, unsigned longs)
+{
+ static int littleEndian = -1;
+ if (littleEndian < 0)
+ {
+ /* Are we little or big endian? This method is from Harbison & Steele. */
+ union
+ {
+ long l;
+ char c[sizeof(long)];
+ } u;
+ u.l = 1;
+ littleEndian = (u.c[0] == 1) ? 1 : 0;
+ }
+
+ if (littleEndian != 1)
+ {
+ unsigned int t;
+ do
+ {
+ t = (unsigned int) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
+ ((unsigned) buf[1] << 8 | buf[0]);
+ *(unsigned int *) buf = t;
+ buf += 4;
+ }
+ while (--longs);
+ }
+}
+
+#if 0
+static char* MD5End(MD5_CTX *, char *);
+
+static char* MD5End(MD5_CTX *ctx, char *buf)
+{
+ int i;
+ unsigned char digest[MD5_HASHBYTES];
+ char hex[]="0123456789abcdef";
+
+ if (!buf)
+ {
+ buf = (char *)malloc(33);
+ }
+
+ if (!buf)
+ {
+ return 0;
+ }
+
+ MD5Final(digest,ctx);
+ for (i=0;i<MD5_HASHBYTES;i++)
+ {
+ buf[i+i] = hex[digest[i] >> 4];
+ buf[i+i+1] = hex[digest[i] & 0x0f];
+ }
+ buf[i+i] = '\0';
+ return buf;
+}
+#endif
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+static void MD5Final(unsigned char digest[16], MD5_CTX *ctx)
+{
+ unsigned count;
+ unsigned char *p;
+
+ /* Compute number of bytes mod 64 */
+ count = (ctx->bits[0] >> 3) & 0x3F;
+
+ /* Set the first char of padding to 0x80. This is safe since there is
+ always at least one byte free */
+ p = ctx->in + count;
+ *p++ = 0x80;
+
+ /* Bytes of padding needed to make 64 bytes */
+ count = 64 - 1 - count;
+
+ /* Pad out to 56 mod 64 */
+ if (count < 8)
+ {
+ /* Two lots of padding: Pad the first block to 64 bytes */
+ memset(p, 0, count);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (unsigned int *) ctx->in);
+
+ /* Now fill the next block with 56 bytes */
+ memset(ctx->in, 0, 56);
+ }
+ else
+ {
+ /* Pad block to 56 bytes */
+ memset(p, 0, count - 8);
+ }
+ byteReverse(ctx->in, 14);
+
+ /* Append length in bits and transform */
+ ((unsigned int *) ctx->in)[14] = ctx->bits[0];
+ ((unsigned int *) ctx->in)[15] = ctx->bits[1];
+
+ MD5Transform(ctx->buf, (unsigned int *) ctx->in);
+ byteReverse((unsigned char *) ctx->buf, 4);
+ memcpy(digest, ctx->buf, 16);
+ memset((char *) ctx, 0, sizeof(ctx)); /* In case it's sensitive */
+}
+
+static void MD5Init(MD5_CTX *ctx)
+{
+ ctx->buf[0] = 0x67452301;
+ ctx->buf[1] = 0xefcdab89;
+ ctx->buf[2] = 0x98badcfe;
+ ctx->buf[3] = 0x10325476;
+
+ ctx->bits[0] = 0;
+ ctx->bits[1] = 0;
+}
+
+static void MD5Update(MD5_CTX *ctx, unsigned char *buf, unsigned len)
+{
+ unsigned int t;
+
+ /* Update bitcount */
+
+ t = ctx->bits[0];
+ if ((ctx->bits[0] = t + ((unsigned int) len << 3)) < t)
+ {
+ ctx->bits[1]++; /* Carry from low to high */
+ }
+ ctx->bits[1] += len >> 29;
+
+ t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
+
+ /* Handle any leading odd-sized chunks */
+
+ if (t)
+ {
+ unsigned char *p = (unsigned char *) ctx->in + t;
+
+ t = 64 - t;
+ if (len < t)
+ {
+ memcpy(p, buf, len);
+ return;
+ }
+ memcpy(p, buf, t);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (unsigned int *) ctx->in);
+ buf += t;
+ len -= t;
+ }
+ /* Process data in 64-byte chunks */
+
+ while (len >= 64)
+ {
+ memcpy(ctx->in, buf, 64);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (unsigned int *) ctx->in);
+ buf += 64;
+ len -= 64;
+ }
+
+ /* Handle any remaining bytes of data. */
+
+ memcpy(ctx->in, buf, len);
+}
+
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+ ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data. MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void MD5Transform(unsigned int buf[4], unsigned int in[16])
+{
+ register unsigned int a, b, c, d;
+
+ a = buf[0];
+ b = buf[1];
+ c = buf[2];
+ d = buf[3];
+
+ MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+ MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+ MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+ MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+ MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+ MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+ MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+ MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+ MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+ MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+ MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+ MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+ MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+ MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+ MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+ MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+ MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+ MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+ MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+ MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+ MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+ MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+ MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+ MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+ MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+ MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+ MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+ MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+ MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+ MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+ MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+ MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+ MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+ MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+ MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+ MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+ MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+ MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+ MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+ MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+ MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+ MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+ MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+ MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+ MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+ MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+ MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+ MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+ MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+ MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+ MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+ MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+ MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+ MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+ MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+ MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+ MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+ MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+ MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+ MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+ MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+ MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+ MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+ MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+ buf[0] += a;
+ buf[1] += b;
+ buf[2] += c;
+ buf[3] += d;
+}
+
+/*
+// ---------------------------
+// RC4 implementation
+// ---------------------------
+*/
+
+/**
+* RC4 is the standard encryption algorithm used in PDF format
+*/
+
+void
+CodecRC4(Codec* codec, unsigned char* key, int keylen,
+ unsigned char* textin, int textlen,
+ unsigned char* textout)
+{
+ int i;
+ int j;
+ int t;
+ unsigned char rc4[256];
+
+ int a = 0;
+ int b = 0;
+ unsigned char k;
+
+ for (i = 0; i < 256; i++)
+ {
+ rc4[i] = i;
+ }
+ j = 0;
+ for (i = 0; i < 256; i++)
+ {
+ t = rc4[i];
+ j = (j + t + key[i % keylen]) % 256;
+ rc4[i] = rc4[j];
+ rc4[j] = t;
+ }
+
+ for (i = 0; i < textlen; i++)
+ {
+ a = (a + 1) % 256;
+ t = rc4[a];
+ b = (b + t) % 256;
+ rc4[a] = rc4[b];
+ rc4[b] = t;
+ k = rc4[(rc4[a] + rc4[b]) % 256];
+ textout[i] = textin[i] ^ k;
+ }
+}
+
+void
+CodecGetMD5Binary(Codec* codec, unsigned char* data, int length, unsigned char* digest)
+{
+ MD5_CTX ctx;
+ MD5Init(&ctx);
+ MD5Update(&ctx, data, length);
+ MD5Final(digest,&ctx);
+}
+
+#if CODEC_TYPE == CODEC_TYPE_AES256
+void
+CodecGetSHABinary(Codec* codec, unsigned char* data, int length, unsigned char* digest)
+{
+ sha256(data, (unsigned int) length, digest);
+}
+#endif
+
+#define MODMULT(a, b, c, m, s) q = s / a; s = b * (s - a * q) - c * q; if (s < 0) s += m
+
+void
+CodecGenerateInitialVector(Codec* codec, int seed, unsigned char iv[16])
+{
+ unsigned char initkey[16];
+ int j, q;
+ int z = seed + 1;
+ for (j = 0; j < 4; j++)
+ {
+ MODMULT(52774, 40692, 3791, 2147483399L, z);
+ initkey[4*j+0] = 0xff & z;
+ initkey[4*j+1] = 0xff & (z >> 8);
+ initkey[4*j+2] = 0xff & (z >> 16);
+ initkey[4*j+3] = 0xff & (z >> 24);
+ }
+ CodecGetMD5Binary(codec, (unsigned char*) initkey, 16, iv);
+}
+
+void
+CodecAES(Codec* codec, int page, int encrypt, unsigned char encryptionKey[KEYLENGTH],
+ unsigned char* datain, int datalen, unsigned char* dataout)
+{
+ unsigned char initial[16];
+ unsigned char pagekey[KEYLENGTH];
+ unsigned char nkey[KEYLENGTH+4+4];
+ int keyLength = KEYLENGTH;
+ int nkeylen = keyLength + 4 + 4;
+ int j;
+ int direction = (encrypt) ? RIJNDAEL_Direction_Encrypt : RIJNDAEL_Direction_Decrypt;
+ int len = 0;
+
+ for (j = 0; j < keyLength; j++)
+ {
+ nkey[j] = encryptionKey[j];
+ }
+ nkey[keyLength+0] = 0xff & page;
+ nkey[keyLength+1] = 0xff & (page >> 8);
+ nkey[keyLength+2] = 0xff & (page >> 16);
+ nkey[keyLength+3] = 0xff & (page >> 24);
+
+ /* AES encryption needs some 'salt' */
+ nkey[keyLength+4] = 0x73;
+ nkey[keyLength+5] = 0x41;
+ nkey[keyLength+6] = 0x6c;
+ nkey[keyLength+7] = 0x54;
+
+#if CODEC_TYPE == CODEC_TYPE_AES256
+ CodecGetSHABinary(codec, nkey, nkeylen, pagekey);
+#else
+ CodecGetMD5Binary(codec, nkey, nkeylen, pagekey);
+#endif
+ CodecGenerateInitialVector(codec, page, initial);
+
+#if CODEC_TYPE == CODEC_TYPE_AES256
+ RijndaelInit(codec->m_aes, RIJNDAEL_Direction_Mode_CBC, direction, pagekey, RIJNDAEL_Direction_KeyLength_Key32Bytes, initial);
+#else
+ RijndaelInit(codec->m_aes, RIJNDAEL_Direction_Mode_CBC, direction, pagekey, RIJNDAEL_Direction_KeyLength_Key16Bytes, initial);
+#endif
+ if (encrypt)
+ {
+ len = RijndaelBlockEncrypt(codec->m_aes, datain, datalen*8, dataout);
+ }
+ else
+ {
+ len = RijndaelBlockDecrypt(codec->m_aes, datain, datalen*8, dataout);
+ }
+
+ /* It is a good idea to check the error code */
+ if (len < 0)
+ {
+ /* AES: Error on encrypting. */
+ }
+}
+
+static unsigned char padding[] =
+ "\x28\xBF\x4E\x5E\x4E\x75\x8A\x41\x64\x00\x4E\x56\xFF\xFA\x01\x08\x2E\x2E\x00\xB6\xD0\x68\x3E\x80\x2F\x0C\xA9\xFE\x64\x53\x69\x7A";
+
+void
+CodecInit(Codec* codec)
+{
+ codec->m_isEncrypted = 0;
+ codec->m_hasReadKey = 0;
+ codec->m_hasWriteKey = 0;
+ codec->m_aes = (Rijndael*) wx_sqlite3_malloc(sizeof(Rijndael));
+ RijndaelCreate(codec->m_aes);
+}
+
+void
+CodecTerm(Codec* codec)
+{
+ wx_sqlite3_free(codec->m_aes);
+}
+
+void
+CodecSetIsEncrypted(Codec* codec, int isEncrypted)
+{
+ codec->m_isEncrypted = isEncrypted;
+}
+
+void
+CodecSetHasReadKey(Codec* codec, int hasReadKey)
+{
+ codec->m_hasReadKey = hasReadKey;
+}
+
+void
+CodecSetHasWriteKey(Codec* codec, int hasWriteKey)
+{
+ codec->m_hasWriteKey = hasWriteKey;
+}
+
+void
+CodecSetBtree(Codec* codec, Btree* bt)
+{
+ codec->m_bt = bt;
+}
+
+int
+CodecIsEncrypted(Codec* codec)
+{
+ return codec->m_isEncrypted;
+}
+
+int
+CodecHasReadKey(Codec* codec)
+{
+ return codec->m_hasReadKey;
+}
+
+int
+CodecHasWriteKey(Codec* codec)
+{
+ return codec->m_hasWriteKey;
+}
+
+Btree*
+CodecGetBtree(Codec* codec)
+{
+ return codec->m_bt;
+}
+
+unsigned char*
+CodecGetPageBuffer(Codec* codec)
+{
+ return &codec->m_page[4];
+}
+
+void
+CodecCopy(Codec* codec, Codec* other)
+{
+ int j;
+ codec->m_isEncrypted = other->m_isEncrypted;
+ codec->m_hasReadKey = other->m_hasReadKey;
+ codec->m_hasWriteKey = other->m_hasWriteKey;
+ for (j = 0; j < KEYLENGTH; j++)
+ {
+ codec->m_readKey[j] = other->m_readKey[j];
+ codec->m_writeKey[j] = other->m_writeKey[j];
+ }
+ codec->m_bt = other->m_bt;
+ RijndaelInvalidate(codec->m_aes);
+}
+
+void
+CodecCopyKey(Codec* codec, int read2write)
+{
+ int j;
+ if (read2write)
+ {
+ for (j = 0; j < KEYLENGTH; j++)
+ {
+ codec->m_writeKey[j] = codec->m_readKey[j];
+ }
+ }
+ else
+ {
+ for (j = 0; j < KEYLENGTH; j++)
+ {
+ codec->m_readKey[j] = codec->m_writeKey[j];
+ }
+ }
+}
+
+void
+CodecPadPassword(Codec* codec, char* password, int pswdlen, unsigned char pswd[32])
+{
+ int j;
+ int p = 0;
+ int m = pswdlen;
+ if (m > 32) m = 32;
+
+ for (j = 0; j < m; j++)
+ {
+ pswd[p++] = (unsigned char) password[j];
+ }
+ for (j = 0; p < 32 && j < 32; j++)
+ {
+ pswd[p++] = padding[j];
+ }
+}
+
+void
+CodecGenerateReadKey(Codec* codec, char* userPassword, int passwordLength)
+{
+ CodecGenerateEncryptionKey(codec, userPassword, passwordLength, codec->m_readKey);
+}
+
+void
+CodecGenerateWriteKey(Codec* codec, char* userPassword, int passwordLength)
+{
+ CodecGenerateEncryptionKey(codec, userPassword, passwordLength, codec->m_writeKey);
+}
+
+void
+CodecGenerateEncryptionKey(Codec* codec, char* userPassword, int passwordLength,
+ unsigned char encryptionKey[KEYLENGTH])
+{
+#if CODEC_TYPE == CODEC_TYPE_AES256
+ unsigned char userPad[32];
+ unsigned char digest[KEYLENGTH];
+ int keyLength = KEYLENGTH;
+ int k;
+
+ /* Pad password */
+ CodecPadPassword(codec, userPassword, passwordLength, userPad);
+
+ sha256(userPad, 32, digest);
+ for (k = 0; k < CODEC_SHA_ITER; ++k)
+ {
+ sha256(digest, KEYLENGTH, digest);
+ }
+ memcpy(encryptionKey, digest, keyLength);
+#else
+ unsigned char userPad[32];
+ unsigned char ownerPad[32];
+ unsigned char ownerKey[32];
+
+ unsigned char mkey[MD5_HASHBYTES];
+ unsigned char digest[MD5_HASHBYTES];
+ int keyLength = MD5_HASHBYTES;
+ int i, j, k;
+ MD5_CTX ctx;
+
+ /* Pad passwords */
+ CodecPadPassword(codec, userPassword, passwordLength, userPad);
+ CodecPadPassword(codec, "", 0, ownerPad);
+
+ /* Compute owner key */
+
+ MD5Init(&ctx);
+ MD5Update(&ctx, ownerPad, 32);
+ MD5Final(digest,&ctx);
+
+ /* only use for the input as many bit as the key consists of */
+ for (k = 0; k < 50; ++k)
+ {
+ MD5Init(&ctx);
+ MD5Update(&ctx, digest, keyLength);
+ MD5Final(digest,&ctx);
+ }
+ memcpy(ownerKey, userPad, 32);
+ for (i = 0; i < 20; ++i)
+ {
+ for (j = 0; j < keyLength ; ++j)
+ {
+ mkey[j] = (digest[j] ^ i);
+ }
+ CodecRC4(codec, mkey, keyLength, ownerKey, 32, ownerKey);
+ }
+
+ /* Compute encryption key */
+
+ MD5Init(&ctx);
+ MD5Update(&ctx, userPad, 32);
+ MD5Update(&ctx, ownerKey, 32);
+ MD5Final(digest,&ctx);
+
+ /* only use the really needed bits as input for the hash */
+ for (k = 0; k < 50; ++k)
+ {
+ MD5Init(&ctx);
+ MD5Update(&ctx, digest, keyLength);
+ MD5Final(digest, &ctx);
+ }
+ memcpy(encryptionKey, digest, keyLength);
+#endif
+}
+
+void
+CodecEncrypt(Codec* codec, int page, unsigned char* data, int len, int useWriteKey)
+{
+#ifdef WXSQLITE3_USE_OLD_ENCRYPTION_SCHEME
+ /* Use the previous encryption scheme */
+ unsigned char* key = (useWriteKey) ? codec->m_writeKey : codec->m_readKey;
+ CodecAES(codec, page, 1, key, data, len, data);
+#else
+ unsigned char dbHeader[8];
+ int offset = 0;
+ unsigned char* key = (useWriteKey) ? codec->m_writeKey : codec->m_readKey;
+ if (page == 1)
+ {
+ /* Save the header bytes remaining unencrypted */
+ memcpy(dbHeader, data+16, 8);
+ offset = 16;
+ CodecAES(codec, page, 1, key, data, 16, data);
+ }
+ CodecAES(codec, page, 1, key, data+offset, len-offset, data+offset);
+ if (page == 1)
+ {
+ /* Move the encrypted header bytes 16..23 to a safe position */
+ memcpy(data+8, data+16, 8);
+ /* Restore the unencrypted header bytes 16..23 */
+ memcpy(data+16, dbHeader, 8);
+ }
+#endif
+}
+
+void
+CodecDecrypt(Codec* codec, int page, unsigned char* data, int len)
+{
+#ifdef WXSQLITE3_USE_OLD_ENCRYPTION_SCHEME
+ /* Use the previous encryption scheme */
+ CodecAES(codec, page, 0, codec->m_readKey, data, len, data);
+#else
+ unsigned char dbHeader[8];
+ int dbPageSize;
+ int offset = 0;
+ if (page == 1)
+ {
+ /* Save (unencrypted) header bytes 16..23 */
+ memcpy(dbHeader, data+16, 8);
+ /* Determine page size */
+ dbPageSize = (dbHeader[0] << 8) | (dbHeader[1] << 16);
+ /* Check whether the database header is valid */
+ /* If yes, the database follows the new encryption scheme, otherwise use the previous encryption scheme */
+ if ((dbPageSize >= 512) && (dbPageSize <= SQLITE_MAX_PAGE_SIZE) && (((dbPageSize-1) & dbPageSize) == 0) &&
+ (dbHeader[5] == 0x40) && (dbHeader[6] == 0x20) && (dbHeader[7] == 0x20))
+ {
+ /* Restore encrypted bytes 16..23 for new encryption scheme */
+ memcpy(data+16, data+8, 8);
+ offset = 16;
+ }
+ }
+ CodecAES(codec, page, 0, codec->m_readKey, data+offset, len-offset, data+offset);
+ if (page == 1 && offset != 0)
+ {
+ /* Verify the database header */
+ if (memcmp(dbHeader, data+16, 8) == 0)
+ {
+ memcpy(data, SQLITE_FILE_HEADER, 16);
+ }
+ }
+#endif
+}
+
+
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