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harbour-core/harbour/external/libhpdf/hpdf_encrypt.c
Viktor Szakats c356496480 2009-03-29 11:02 UTC+0200 Viktor Szakats (harbour.01 syenar hu) 
* INSTALL
  * external/Makefile
  + external/libhpdf/*
  + external/libpng/*
    + Added libharu and libpng to Harbour repository.
      Now it's possible to use libhpdf as static lib on all
      platforms. This is useful because this lib isn't yet part
      of Linux distros.
      libpng is only built for win/dos/os2 platforms.
      It's possible to override libpng location by using
      HB_INC_LIBPNG envvar.

  * contrib/hbhpdf/Makefile
    + Look for libharu headers in /external dir.

  * external/sqlite3/Makefile
    - Disabled for bcc. Latest sqlite3 version breaks with this compiler:
      ---
      Error E2293 ../../sqlite3.c 29156: ) expected in function winCurrentTime
      Warning W8013 ../../sqlite3.c 29157: Possible use of 'timeW' before definition in function winCurrentTime
      Error E2379 ../../sqlite3.c 29157: Statement missing ; in function winCurrentTime
      Error E2379 ../../sqlite3.c 29158: Statement missing ; in function winCurrentTime
      Error E2379 ../../sqlite3.c 29160: Statement missing ; in function winCurrentTime
      Error E2293 ../../sqlite3.c 29161: ) expected in function winCurrentTime
      Error E2379 ../../sqlite3.c 29162: Statement missing ; in function winCurrentTime
      Error E2293 ../../sqlite3.c 29163: ) expected in function winCurrentTime
      Warning W8057 ../../sqlite3.c 29171: Parameter 'prNow' is never used in function winCurrentTime
      *** 7 errors in Compile ***
      ---
      bcc users can report this problem here:
      http://www.sqlite.org/cvstrac/tktnew

  + tests/bnch_win.bat
  - tests/bnchmark
    * Moved bnch_win.bat to tests.
2009-03-29 09:09:24 +00:00

636 lines
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/*
* << Haru Free PDF Library >> -- hpdf_encryor.c
*
* URL: http://libharu.org
*
* Copyright (c) 1999-2006 Takeshi Kanno <takeshi_kanno@est.hi-ho.ne.jp>
* Copyright (c) 2007-2008 Antony Dovgal <tony@daylessday.org>
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation.
* It is provided "as is" without express or implied warranty.
*
*------------------------------------------------------------------------------
*
* The code implements MD5 message-digest algorithm is based on the code
* written by Colin Plumb.
* The copyright of it is as follows.
*
* This code implements the MD5 message-digest algorithm.
* The algorithm is due to Ron Rivest. This code was
* written by Colin Plumb in 1993, no copyright is claimed.
* This code is in the public domain; do with it what you wish.
*
* Equivalent code is available from RSA Data Security, Inc.
* This code has been tested against that, and is equivalent,
* except that you don't need to include two pages of legalese
* with every copy.
*
* To compute the message digest of a chunk of bytes, declare an
* MD5Context structure, pass it to MD5Init, call MD5Update as
* needed on buffers full of bytes, and then call MD5Final, which
* will fill a supplied 16-byte array with the digest.
*
*---------------------------------------------------------------------------*/
#include "hpdf_conf.h"
#include "hpdf_consts.h"
#include "hpdf_utils.h"
#include "hpdf_encrypt.h"
static const HPDF_BYTE HPDF_PADDING_STRING[] = {
0x28, 0xBF, 0x4E, 0x5E, 0x4E, 0x75, 0x8A, 0x41,
0x64, 0x00, 0x4E, 0x56, 0xFF, 0xFA, 0x01, 0x08,
0x2E, 0x2E, 0x00, 0xB6, 0xD0, 0x68, 0x3E, 0x80,
0x2F, 0x0C, 0xA9, 0xFE, 0x64, 0x53, 0x69, 0x7A
};
/*---------------------------------------------------------------------------*/
/*------ MD5 message-digest algorithm ---------------------------------------*/
static void
MD5Transform (HPDF_UINT32 buf[4],
const HPDF_UINT32 in[16]);
static void
MD5ByteReverse (HPDF_BYTE *buf,
HPDF_UINT32 longs);
void
HPDF_MD5Init (struct HPDF_MD5Context *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;
}
void
HPDF_MD5Update (struct HPDF_MD5Context *ctx,
const HPDF_BYTE *buf,
HPDF_UINT32 len)
{
HPDF_UINT32 t;
/* Update bitcount */
t = ctx->bits[0];
if ((ctx->bits[0] = t + ((HPDF_UINT32) 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) {
HPDF_BYTE *p = (HPDF_BYTE *) ctx->in + t;
t = 64 - t;
if (len < t)
{
HPDF_MemCpy (p, buf, len);
return;
}
HPDF_MemCpy (p, buf, t);
MD5ByteReverse (ctx->in, 16);
MD5Transform (ctx->buf, (HPDF_UINT32 *) ctx->in);
buf += t;
len -= t;
}
/* Process data in 64-byte chunks */
while (len >= 64) {
HPDF_MemCpy (ctx->in, buf, 64);
MD5ByteReverse (ctx->in, 16);
MD5Transform (ctx->buf, (HPDF_UINT32 *) ctx->in);
buf += 64;
len -= 64;
}
/* Handle any remaining bytes of data. */
HPDF_MemCpy (ctx->in, buf, len);
}
/*
* Final wrapup - pad to 64-byte boundary with the bit pattern
* 1 0* (64-bit count of bits processed, MSB-first)
*/
void
HPDF_MD5Final (HPDF_BYTE digest[16],
struct HPDF_MD5Context *ctx)
{
HPDF_UINT32 count;
HPDF_BYTE *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 */
HPDF_MemSet (p, 0, count);
MD5ByteReverse (ctx->in, 16);
MD5Transform (ctx->buf, (HPDF_UINT32 *) ctx->in);
/* Now fill the next block with 56 bytes */
HPDF_MemSet (ctx->in, 0, 56);
} else {
/* Pad block to 56 bytes */
HPDF_MemSet (p, 0, count - 8);
}
MD5ByteReverse (ctx->in, 14);
/* Append length in bits and transform */
((HPDF_UINT32 *) ctx->in)[14] = ctx->bits[0];
((HPDF_UINT32 *) ctx->in)[15] = ctx->bits[1];
MD5Transform (ctx->buf, (HPDF_UINT32 *) ctx->in);
MD5ByteReverse ((HPDF_BYTE *) ctx->buf, 4);
HPDF_MemCpy ((HPDF_BYTE *)digest, (HPDF_BYTE *)ctx->buf, 16);
HPDF_MemSet ((HPDF_BYTE *)ctx, 0, sizeof (ctx)); /* In case it's sensitive */
}
/* The four core functions - F1 is optimized somewhat */
/* #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 HPDF_MD5 algorithm. */
#define HPDF_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 (HPDF_UINT32 buf[4],
const HPDF_UINT32 in[16])
{
register HPDF_UINT32 a, b, c, d;
a = buf[0];
b = buf[1];
c = buf[2];
d = buf[3];
HPDF_MD5STEP (F1, a, b, c, d, in[0] + 0xd76aa478, 7);
HPDF_MD5STEP (F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
HPDF_MD5STEP (F1, c, d, a, b, in[2] + 0x242070db, 17);
HPDF_MD5STEP (F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
HPDF_MD5STEP (F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
HPDF_MD5STEP (F1, d, a, b, c, in[5] + 0x4787c62a, 12);
HPDF_MD5STEP (F1, c, d, a, b, in[6] + 0xa8304613, 17);
HPDF_MD5STEP (F1, b, c, d, a, in[7] + 0xfd469501, 22);
HPDF_MD5STEP (F1, a, b, c, d, in[8] + 0x698098d8, 7);
HPDF_MD5STEP (F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
HPDF_MD5STEP (F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
HPDF_MD5STEP (F1, b, c, d, a, in[11] + 0x895cd7be, 22);
HPDF_MD5STEP (F1, a, b, c, d, in[12] + 0x6b901122, 7);
HPDF_MD5STEP (F1, d, a, b, c, in[13] + 0xfd987193, 12);
HPDF_MD5STEP (F1, c, d, a, b, in[14] + 0xa679438e, 17);
HPDF_MD5STEP (F1, b, c, d, a, in[15] + 0x49b40821, 22);
HPDF_MD5STEP (F2, a, b, c, d, in[1] + 0xf61e2562, 5);
HPDF_MD5STEP (F2, d, a, b, c, in[6] + 0xc040b340, 9);
HPDF_MD5STEP (F2, c, d, a, b, in[11] + 0x265e5a51, 14);
HPDF_MD5STEP (F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
HPDF_MD5STEP (F2, a, b, c, d, in[5] + 0xd62f105d, 5);
HPDF_MD5STEP (F2, d, a, b, c, in[10] + 0x02441453, 9);
HPDF_MD5STEP (F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
HPDF_MD5STEP (F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
HPDF_MD5STEP (F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
HPDF_MD5STEP (F2, d, a, b, c, in[14] + 0xc33707d6, 9);
HPDF_MD5STEP (F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
HPDF_MD5STEP (F2, b, c, d, a, in[8] + 0x455a14ed, 20);
HPDF_MD5STEP (F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
HPDF_MD5STEP (F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
HPDF_MD5STEP (F2, c, d, a, b, in[7] + 0x676f02d9, 14);
HPDF_MD5STEP (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
HPDF_MD5STEP (F3, a, b, c, d, in[5] + 0xfffa3942, 4);
HPDF_MD5STEP (F3, d, a, b, c, in[8] + 0x8771f681, 11);
HPDF_MD5STEP (F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
HPDF_MD5STEP (F3, b, c, d, a, in[14] + 0xfde5380c, 23);
HPDF_MD5STEP (F3, a, b, c, d, in[1] + 0xa4beea44, 4);
HPDF_MD5STEP (F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
HPDF_MD5STEP (F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
HPDF_MD5STEP (F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
HPDF_MD5STEP (F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
HPDF_MD5STEP (F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
HPDF_MD5STEP (F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
HPDF_MD5STEP (F3, b, c, d, a, in[6] + 0x04881d05, 23);
HPDF_MD5STEP (F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
HPDF_MD5STEP (F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
HPDF_MD5STEP (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
HPDF_MD5STEP (F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
HPDF_MD5STEP (F4, a, b, c, d, in[0] + 0xf4292244, 6);
HPDF_MD5STEP (F4, d, a, b, c, in[7] + 0x432aff97, 10);
HPDF_MD5STEP (F4, c, d, a, b, in[14] + 0xab9423a7, 15);
HPDF_MD5STEP (F4, b, c, d, a, in[5] + 0xfc93a039, 21);
HPDF_MD5STEP (F4, a, b, c, d, in[12] + 0x655b59c3, 6);
HPDF_MD5STEP (F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
HPDF_MD5STEP (F4, c, d, a, b, in[10] + 0xffeff47d, 15);
HPDF_MD5STEP (F4, b, c, d, a, in[1] + 0x85845dd1, 21);
HPDF_MD5STEP (F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
HPDF_MD5STEP (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
HPDF_MD5STEP (F4, c, d, a, b, in[6] + 0xa3014314, 15);
HPDF_MD5STEP (F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
HPDF_MD5STEP (F4, a, b, c, d, in[4] + 0xf7537e82, 6);
HPDF_MD5STEP (F4, d, a, b, c, in[11] + 0xbd3af235, 10);
HPDF_MD5STEP (F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
HPDF_MD5STEP (F4, b, c, d, a, in[9] + 0xeb86d391, 21);
buf[0] += a;
buf[1] += b;
buf[2] += c;
buf[3] += d;
}
static void
MD5ByteReverse (HPDF_BYTE *buf,
HPDF_UINT32 longs)
{
HPDF_UINT32 t;
do
{
t = (HPDF_UINT32) ((HPDF_UINT32) buf[3] << 8 | buf[2]) << 16 |
((HPDF_UINT32) buf[1] << 8 | buf[0]);
*(HPDF_UINT32 *) buf = t;
buf += 4;
}
while (--longs);
}
/*----- encrypt-obj ---------------------------------------------------------*/
static void
ARC4Init (HPDF_ARC4_Ctx_Rec *ctx,
const HPDF_BYTE *key,
HPDF_UINT key_len);
static void
ARC4CryptBuf (HPDF_ARC4_Ctx_Rec *ctx,
const HPDF_BYTE *in,
HPDF_BYTE *out,
HPDF_UINT len);
/*---------------------------------------------------------------------------*/
void
HPDF_PadOrTrancatePasswd (const char *pwd,
HPDF_BYTE *new_pwd)
{
HPDF_UINT len = HPDF_StrLen (pwd, HPDF_PASSWD_LEN + 1);
HPDF_PTRACE((" HPDF_PadOrTrancatePasswd\n"));
HPDF_MemSet (new_pwd, 0x00, HPDF_PASSWD_LEN);
if (len >= HPDF_PASSWD_LEN) {
HPDF_MemCpy (new_pwd, (HPDF_BYTE *)pwd, HPDF_PASSWD_LEN);
} else {
if (len > 0) {
HPDF_MemCpy (new_pwd, (HPDF_BYTE *)pwd, len);
}
HPDF_MemCpy (new_pwd + len, HPDF_PADDING_STRING, HPDF_PASSWD_LEN - len);
}
}
void
HPDF_Encrypt_Init (HPDF_Encrypt attr)
{
HPDF_MemSet (attr, 0, sizeof(HPDF_Encrypt_Rec));
attr->mode = HPDF_ENCRYPT_R2;
attr->key_len = 5;
HPDF_MemCpy (attr->owner_passwd, HPDF_PADDING_STRING, HPDF_PASSWD_LEN);
HPDF_MemCpy (attr->user_passwd, HPDF_PADDING_STRING, HPDF_PASSWD_LEN);
attr->permission = HPDF_ENABLE_PRINT | HPDF_ENABLE_EDIT_ALL |
HPDF_ENABLE_COPY | HPDF_ENABLE_EDIT | HPDF_PERMISSION_PAD;
}
void
HPDF_Encrypt_CreateOwnerKey (HPDF_Encrypt attr)
{
HPDF_ARC4_Ctx_Rec rc4_ctx;
HPDF_MD5_CTX md5_ctx;
HPDF_BYTE digest[HPDF_MD5_KEY_LEN];
HPDF_BYTE tmppwd[HPDF_PASSWD_LEN];
HPDF_PTRACE((" HPDF_Encrypt_CreateOwnerKey\n"));
/* create md5-digest using the value of owner_passwd */
/* Algorithm 3.3 step 2 */
HPDF_MD5Init(&md5_ctx);
HPDF_MD5Update(&md5_ctx, attr->owner_passwd, HPDF_PASSWD_LEN);
HPDF_PTRACE(("@ Algorithm 3.3 step 2\n"));
HPDF_MD5Final(digest, &md5_ctx);
/* Algorithm 3.3 step 3 (Revision 3 only) */
if (attr->mode == HPDF_ENCRYPT_R3) {
HPDF_UINT i;
for (i = 0; i < 50; i++) {
HPDF_MD5Init(&md5_ctx);
//HPDF_MD5Update (&md5_ctx, digest, HPDF_MD5_KEY_LEN);
HPDF_MD5Update (&md5_ctx, digest, attr->key_len);
HPDF_MD5Final(digest, &md5_ctx);
HPDF_PTRACE(("@ Algorithm 3.3 step 3 loop %u\n", i));
}
}
/* Algorithm 3.3 step 4 */
HPDF_PTRACE(("@ Algorithm 3.3 step 7 loop 0\n"));
ARC4Init (&rc4_ctx, digest, attr->key_len);
HPDF_PTRACE(("@ Algorithm 3.3 step 5\n"));
/* Algorithm 3.3 step 6 */
HPDF_PTRACE(("@ Algorithm 3.3 step 6\n"));
ARC4CryptBuf (&rc4_ctx, attr->user_passwd, tmppwd, HPDF_PASSWD_LEN);
/* Algorithm 3.3 step 7 */
HPDF_PTRACE(("@ Algorithm 3.3 step 7\n"));
if (attr->mode == HPDF_ENCRYPT_R3) {
HPDF_BYTE tmppwd2[HPDF_PASSWD_LEN];
HPDF_UINT i;
for (i = 1; i <= 19; i++) {
HPDF_UINT j;
HPDF_BYTE new_key[HPDF_MD5_KEY_LEN];
for (j = 0; j < attr->key_len; j++)
new_key[j] = digest[j] ^ i;
HPDF_PTRACE(("@ Algorithm 3.3 step 7 loop %u\n", i));
HPDF_MemCpy (tmppwd2, tmppwd, HPDF_PASSWD_LEN);
ARC4Init(&rc4_ctx, new_key, attr->key_len);
ARC4CryptBuf(&rc4_ctx, tmppwd2, tmppwd, HPDF_PASSWD_LEN);
}
}
/* Algorithm 3.3 step 8 */
HPDF_PTRACE(("@ Algorithm 3.3 step 8\n"));
HPDF_MemCpy (attr->owner_key, tmppwd, HPDF_PASSWD_LEN);
}
void
HPDF_Encrypt_CreateEncryptionKey (HPDF_Encrypt attr)
{
HPDF_MD5_CTX md5_ctx;
HPDF_BYTE tmp_flg[4];
HPDF_PTRACE((" HPDF_Encrypt_CreateEncryptionKey\n"));
/* Algorithm3.2 step2 */
HPDF_MD5Init(&md5_ctx);
HPDF_MD5Update(&md5_ctx, attr->user_passwd, HPDF_PASSWD_LEN);
/* Algorithm3.2 step3 */
HPDF_MD5Update(&md5_ctx, attr->owner_key, HPDF_PASSWD_LEN);
/* Algorithm3.2 step4 */
HPDF_PTRACE(("@@@ permission =%d\n", attr->permission));
tmp_flg[0] = attr->permission;
tmp_flg[1] = (attr->permission >> 8);
tmp_flg[2] = (attr->permission >> 16);
tmp_flg[3] = (attr->permission >> 24);
HPDF_MD5Update(&md5_ctx, tmp_flg, 4);
/* Algorithm3.2 step5 */
HPDF_PTRACE(("@ Algorithm 3.2 step 5\n"));
HPDF_MD5Update(&md5_ctx, attr->encrypt_id, HPDF_ID_LEN);
HPDF_MD5Final(attr->encryption_key, &md5_ctx);
/* Algorithm 3.2 step6 (Revision 3 only) */
if (attr->mode == HPDF_ENCRYPT_R3) {
HPDF_UINT i;
for (i = 0; i < 50; i++) {
HPDF_PTRACE(("@ Algorithm 3.3 step 6 loop %u\n", i));
HPDF_MD5Init(&md5_ctx);
HPDF_MD5Update (&md5_ctx, attr->encryption_key, attr->key_len);
HPDF_MD5Final(attr->encryption_key, &md5_ctx);
}
}
}
void
HPDF_Encrypt_CreateUserKey (HPDF_Encrypt attr)
{
HPDF_ARC4_Ctx_Rec ctx;
HPDF_PTRACE((" HPDF_Encrypt_CreateUserKey\n"));
/* Algorithm 3.4/5 step1 */
/* Algorithm 3.4 step2 */
ARC4Init(&ctx, attr->encryption_key, attr->key_len);
ARC4CryptBuf(&ctx, HPDF_PADDING_STRING, attr->user_key, HPDF_PASSWD_LEN);
if (attr->mode == HPDF_ENCRYPT_R3) {
HPDF_MD5_CTX md5_ctx;
HPDF_BYTE digest[HPDF_MD5_KEY_LEN];
HPDF_BYTE digest2[HPDF_MD5_KEY_LEN];
HPDF_UINT i;
/* Algorithm 3.5 step2 (same as Algorithm3.2 step2) */
HPDF_MD5Init(&md5_ctx);
HPDF_MD5Update(&md5_ctx, HPDF_PADDING_STRING, HPDF_PASSWD_LEN);
/* Algorithm 3.5 step3 */
HPDF_MD5Update(&md5_ctx, attr->encrypt_id, HPDF_ID_LEN);
HPDF_MD5Final(digest, &md5_ctx);
HPDF_PTRACE(("@ Algorithm 3.5 step 3\n"));
/* Algorithm 3.5 step4 */
ARC4Init(&ctx, attr->encryption_key, attr->key_len);
ARC4CryptBuf(&ctx, digest, digest2, HPDF_MD5_KEY_LEN);
HPDF_PTRACE(("@ Algorithm 3.5 step 4\n"));
/* Algorithm 3.5 step5 */
for (i = 1; i <= 19; i++) {
HPDF_UINT j;
HPDF_BYTE new_key[HPDF_MD5_KEY_LEN];
HPDF_PTRACE(("@ Algorithm 3.5 step 5 loop %u\n", i));
for (j = 0; j < attr->key_len; j++)
new_key[j] = attr->encryption_key[j] ^ i;
HPDF_MemCpy (digest, digest2, HPDF_MD5_KEY_LEN);
ARC4Init(&ctx, new_key, attr->key_len);
ARC4CryptBuf(&ctx, digest, digest2, HPDF_MD5_KEY_LEN);
}
/* use the result of Algorithm 3.4 as 'arbitrary padding' */
HPDF_MemSet (attr->user_key, 0, HPDF_PASSWD_LEN);
HPDF_MemCpy (attr->user_key, digest2, HPDF_MD5_KEY_LEN);
}
}
void
ARC4Init (HPDF_ARC4_Ctx_Rec *ctx,
const HPDF_BYTE *key,
HPDF_UINT key_len)
{
HPDF_BYTE tmp_array[HPDF_ARC4_BUF_SIZE];
HPDF_UINT i;
HPDF_UINT j = 0;
HPDF_PTRACE((" ARC4Init\n"));
for (i = 0; i < HPDF_ARC4_BUF_SIZE; i++)
ctx->state[i] = i;
for (i = 0; i < HPDF_ARC4_BUF_SIZE; i++)
tmp_array[i] = key[i % key_len];
for (i = 0; i < HPDF_ARC4_BUF_SIZE; i++) {
HPDF_BYTE tmp;
j = (j + ctx->state[i] + tmp_array[i]) % HPDF_ARC4_BUF_SIZE;
tmp = ctx->state[i];
ctx->state[i] = ctx->state[j];
ctx->state[j] = tmp;
}
ctx->idx1 = 0;
ctx->idx2 = 0;
}
void
ARC4CryptBuf (HPDF_ARC4_Ctx_Rec *ctx,
const HPDF_BYTE *in,
HPDF_BYTE *out,
HPDF_UINT len)
{
HPDF_UINT i;
HPDF_UINT t;
HPDF_BYTE K;
HPDF_PTRACE((" ARC4CryptBuf\n"));
for (i = 0; i < len; i++) {
HPDF_BYTE tmp;
ctx->idx1 = (ctx->idx1 + 1) % 256;
ctx->idx2 = (ctx->idx2 + ctx->state[ctx->idx1]) % 256;
tmp = ctx->state[ctx->idx1];
ctx->state[ctx->idx1] = ctx->state[ctx->idx2];
ctx->state[ctx->idx2] = tmp;
t = (ctx->state[ctx->idx1] + ctx->state[ctx->idx2]) % 256;
K = ctx->state[t];
out[i] = in[i] ^ K;
}
}
void
HPDF_Encrypt_InitKey (HPDF_Encrypt attr,
HPDF_UINT32 object_id,
HPDF_UINT16 gen_no)
{
HPDF_MD5_CTX ctx;
HPDF_UINT key_len;
HPDF_PTRACE((" HPDF_Encrypt_Init\n"));
attr->encryption_key[attr->key_len] = object_id;
attr->encryption_key[attr->key_len + 1] = (object_id >> 8);
attr->encryption_key[attr->key_len + 2] = (object_id >> 16);
attr->encryption_key[attr->key_len + 3] = gen_no;
attr->encryption_key[attr->key_len + 4] = (gen_no >> 8);
HPDF_PTRACE(("@@@ OID=%u, gen_no=%u\n", (HPDF_INT)object_id, gen_no));
HPDF_MD5Init(&ctx);
HPDF_MD5Update(&ctx, attr->encryption_key, attr->key_len + 5);
HPDF_MD5Final(attr->md5_encryption_key, &ctx);
key_len = (attr->key_len + 5 > HPDF_ENCRYPT_KEY_MAX) ?
HPDF_ENCRYPT_KEY_MAX : attr->key_len + 5;
ARC4Init(&attr->arc4ctx, attr->md5_encryption_key, key_len);
}
void
HPDF_Encrypt_Reset (HPDF_Encrypt attr)
{
HPDF_UINT key_len = (attr->key_len + 5 > HPDF_ENCRYPT_KEY_MAX) ?
HPDF_ENCRYPT_KEY_MAX : attr->key_len + 5;
HPDF_PTRACE((" HPDF_Encrypt_Reset\n"));
ARC4Init(&attr->arc4ctx, attr->md5_encryption_key, key_len);
}
void
HPDF_Encrypt_CryptBuf (HPDF_Encrypt attr,
const HPDF_BYTE *src,
HPDF_BYTE *dst,
HPDF_UINT len)
{
ARC4CryptBuf(&attr->arc4ctx, src, dst, len);
}
/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/
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