/* * << Haru Free PDF Library 2.0.0 >> -- hpdf_encryor.c * * Copyright (c) 1999-2006 Takeshi Kanno * * 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<>(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, pwd, HPDF_PASSWD_LEN); else { if (len > 0) HPDF_MemCpy (new_pwd, 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); } /*--------------------------------------------------------------------------*/ /*--------------------------------------------------------------------------*/