misc/quazip/crypt.h
changeset 8057 93e16240f178
parent 8051 f26422ef0333
parent 8055 04dd8b7fb605
child 8058 bcebfc477459
--- a/misc/quazip/crypt.h	Sat Nov 17 09:03:47 2012 -0500
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,135 +0,0 @@
-/* crypt.h -- base code for crypt/uncrypt ZIPfile
-
-
-   Version 1.01e, February 12th, 2005
-
-   Copyright (C) 1998-2005 Gilles Vollant
-
-   This code is a modified version of crypting code in Infozip distribution
-
-   The encryption/decryption parts of this source code (as opposed to the
-   non-echoing password parts) were originally written in Europe.  The
-   whole source package can be freely distributed, including from the USA.
-   (Prior to January 2000, re-export from the US was a violation of US law.)
-
-   This encryption code is a direct transcription of the algorithm from
-   Roger Schlafly, described by Phil Katz in the file appnote.txt.  This
-   file (appnote.txt) is distributed with the PKZIP program (even in the
-   version without encryption capabilities).
-
-   If you don't need crypting in your application, just define symbols
-   NOCRYPT and NOUNCRYPT.
-
-   This code support the "Traditional PKWARE Encryption".
-
-   The new AES encryption added on Zip format by Winzip (see the page
-   http://www.winzip.com/aes_info.htm ) and PKWare PKZip 5.x Strong
-   Encryption is not supported.
-*/
-
-#include "quazip_global.h"
-
-#define CRC32(c, b) ((*(pcrc_32_tab+(((int)(c) ^ (b)) & 0xff))) ^ ((c) >> 8))
-
-/***********************************************************************
- * Return the next byte in the pseudo-random sequence
- */
-static int decrypt_byte(unsigned long* pkeys, const unsigned long* pcrc_32_tab UNUSED)
-{
-    //(void) pcrc_32_tab; /* avoid "unused parameter" warning */
-    unsigned temp;  /* POTENTIAL BUG:  temp*(temp^1) may overflow in an
-                     * unpredictable manner on 16-bit systems; not a problem
-                     * with any known compiler so far, though */
-
-    temp = ((unsigned)(*(pkeys+2)) & 0xffff) | 2;
-    return (int)(((temp * (temp ^ 1)) >> 8) & 0xff);
-}
-
-/***********************************************************************
- * Update the encryption keys with the next byte of plain text
- */
-static int update_keys(unsigned long* pkeys,const unsigned long* pcrc_32_tab,int c)
-{
-    (*(pkeys+0)) = CRC32((*(pkeys+0)), c);
-    (*(pkeys+1)) += (*(pkeys+0)) & 0xff;
-    (*(pkeys+1)) = (*(pkeys+1)) * 134775813L + 1;
-    {
-      register int keyshift = (int)((*(pkeys+1)) >> 24);
-      (*(pkeys+2)) = CRC32((*(pkeys+2)), keyshift);
-    }
-    return c;
-}
-
-
-/***********************************************************************
- * Initialize the encryption keys and the random header according to
- * the given password.
- */
-static void init_keys(const char* passwd,unsigned long* pkeys,const unsigned long* pcrc_32_tab)
-{
-    *(pkeys+0) = 305419896L;
-    *(pkeys+1) = 591751049L;
-    *(pkeys+2) = 878082192L;
-    while (*passwd != '\0') {
-        update_keys(pkeys,pcrc_32_tab,(int)*passwd);
-        passwd++;
-    }
-}
-
-#define zdecode(pkeys,pcrc_32_tab,c) \
-    (update_keys(pkeys,pcrc_32_tab,c ^= decrypt_byte(pkeys,pcrc_32_tab)))
-
-#define zencode(pkeys,pcrc_32_tab,c,t) \
-    (t=decrypt_byte(pkeys,pcrc_32_tab), update_keys(pkeys,pcrc_32_tab,c), t^(c))
-
-#ifdef INCLUDECRYPTINGCODE_IFCRYPTALLOWED
-
-#define RAND_HEAD_LEN  12
-   /* "last resort" source for second part of crypt seed pattern */
-#  ifndef ZCR_SEED2
-#    define ZCR_SEED2 3141592654UL     /* use PI as default pattern */
-#  endif
-
-static int crypthead(passwd, buf, bufSize, pkeys, pcrc_32_tab, crcForCrypting)
-    const char *passwd;         /* password string */
-    unsigned char *buf;         /* where to write header */
-    int bufSize;
-    unsigned long* pkeys;
-    const unsigned long* pcrc_32_tab;
-    unsigned long crcForCrypting;
-{
-    int n;                       /* index in random header */
-    int t;                       /* temporary */
-    int c;                       /* random byte */
-    unsigned char header[RAND_HEAD_LEN-2]; /* random header */
-    static unsigned calls = 0;   /* ensure different random header each time */
-
-    if (bufSize<RAND_HEAD_LEN)
-      return 0;
-
-    /* First generate RAND_HEAD_LEN-2 random bytes. We encrypt the
-     * output of rand() to get less predictability, since rand() is
-     * often poorly implemented.
-     */
-    if (++calls == 1)
-    {
-        srand((unsigned)(time(NULL) ^ ZCR_SEED2));
-    }
-    init_keys(passwd, pkeys, pcrc_32_tab);
-    for (n = 0; n < RAND_HEAD_LEN-2; n++)
-    {
-        c = (rand() >> 7) & 0xff;
-        header[n] = (unsigned char)zencode(pkeys, pcrc_32_tab, c, t);
-    }
-    /* Encrypt random header (last two bytes is high word of crc) */
-    init_keys(passwd, pkeys, pcrc_32_tab);
-    for (n = 0; n < RAND_HEAD_LEN-2; n++)
-    {
-        buf[n] = (unsigned char)zencode(pkeys, pcrc_32_tab, header[n], t);
-    }
-    buf[n++] = zencode(pkeys, pcrc_32_tab, (int)(crcForCrypting >> 16) & 0xff, t);
-    buf[n++] = zencode(pkeys, pcrc_32_tab, (int)(crcForCrypting >> 24) & 0xff, t);
-    return n;
-}
-
-#endif