Helper module for uuencode and binhex coders

2 files changed, 605 insertions, 0 deletions

diff --git a/Modules/Setup.in b/Modules/Setup.in
index 0f9a2ff..a0939a9 100644
--- a/Modules/Setup.in
+++ b/Modules/Setup.in
@@ -300,6 +300,9 @@ rotor rotormodule.c		# enigma-inspired encryption
 # Objective-C (incomplete!!!)
 #objc.c
 
+# Helper module for various ascii-encoders
+binascii binasciimodule.c
+
 
 # Example -- included for reference only:
 # xx xxmodule.c
diff --git a/Modules/binascii.c b/Modules/binascii.c
new file mode 100644
index 0000000..100165d
--- /dev/null
+++ b/Modules/binascii.c
@@ -0,0 +1,602 @@
+/***********************************************************
+Copyright 1991, 1992, 1993, 1994 by Stichting Mathematisch Centrum,
+Amsterdam, The Netherlands.
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its 
+documentation for any purpose and without fee is hereby granted, 
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in 
+supporting documentation, and that the names of Stichting Mathematisch
+Centrum or CWI not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior permission.
+
+STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
+THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
+FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+******************************************************************/
+
+/*
+** Routines to represent binary data in ASCII and vice-versa
+**
+** This module currently supports the following encodings:
+** uuencode:
+**     	each line encodes 45 bytes (except possibly the last)
+**	First char encodes (binary) length, rest data
+**	each char encodes 6 bits, as follows:
+**	binary: 01234567 abcdefgh ijklmnop
+**	ascii:  012345 67abcd efghij klmnop
+**	ASCII encoding method is "excess-space": 000000 is encoded as ' ', etc.
+**	short binary data is zero-extended (so the bits are always in the
+**	right place), this does *not* reflect in the length.
+** hqx:
+**	File starts with introductory text, real data starts and ends
+**	with colons.
+**	Data consists of three similar parts: info, datafork, resourcefork.
+**	Each part is protected (at the end) with a 16-bit crc
+**	The binary data is run-length encoded, and then ascii-fied:
+**	binary: 01234567 abcdefgh ijklmnop
+**	ascii:  012345 67abcd efghij klmnop
+**	ASCII encoding is table-driven, see the code.
+**	Short binary data results in the runt ascii-byte being output with
+**	the bits in the right place.
+**
+** While I was reading dozens of programs that encode or decode the formats
+** here (documentation? hihi:-) I have formulated Jansen's Observation:
+**
+**	Programs that encode binary data in ASCII are written in
+**	such a style that they are as unreadable as possible. Devices used
+**	include unnecessary global variables, burying important tables
+**	in unrelated sourcefiles, putting functions in include files,
+**	using seemingly-descriptive variable names for different purposes,
+**	calls to empty subroutines and a host of others.
+**
+** I have attempted to break with this tradition, but I guess that that
+** does make the performance sub-optimal. Oh well, too bad...
+**
+** Jack Jansen, CWI, July 1995.
+*/
+
+
+#include "Python.h"
+
+static PyObject *Error;
+static PyObject *Incomplete;
+
+/*
+** hqx lookup table, ascii->binary.
+*/
+
+#define RUNCHAR 0x90
+
+#define DONE 0x7F
+#define SKIP 0x7E
+#define FAIL 0x7D
+
+static unsigned char table_a2b_hqx[256] = {
+/*       ^@    ^A    ^B    ^C    ^D    ^E    ^F    ^G   */
+/* 0*/	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+/*       \b    \t    \n    ^K    ^L    \r    ^N    ^O   */
+/* 1*/	FAIL, FAIL, SKIP, FAIL, FAIL, SKIP, FAIL, FAIL,
+/*       ^P    ^Q    ^R    ^S    ^T    ^U    ^V    ^W   */
+/* 2*/	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+/*       ^X    ^Y    ^Z    ^[    ^\    ^]    ^^    ^_   */
+/* 3*/	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+/*              !     "     #     $     %     &     '   */
+/* 4*/	FAIL, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
+/*        (     )     *     +     ,     -     .     /   */
+/* 5*/	0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, FAIL, FAIL,
+/*        0     1     2     3     4     5     6     7   */
+/* 6*/	0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, FAIL,
+/*        8     9     :     ;     <     =     >     ?   */
+/* 7*/	0x14, 0x15, DONE, FAIL, FAIL, FAIL, FAIL, FAIL,
+/*        @     A     B     C     D     E     F     G   */
+/* 8*/	0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+/*        H     I     J     K     L     M     N     O   */
+/* 9*/	0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, FAIL,
+/*        P     Q     R     S     T     U     V     W   */
+/*10*/	0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, FAIL,
+/*        X     Y     Z     [     \     ]     ^     _   */
+/*11*/	0x2C, 0x2D, 0x2E, 0x2F, FAIL, FAIL, FAIL, FAIL,
+/*        `     a     b     c     d     e     f     g   */
+/*12*/	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, FAIL,
+/*        h     i     j     k     l     m     n     o   */
+/*13*/	0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, FAIL, FAIL,
+/*        p     q     r     s     t     u     v     w   */
+/*14*/	0x3D, 0x3E, 0x3F, FAIL, FAIL, FAIL, FAIL, FAIL,
+/*        x     y     z     {     |     }     ~    ^?   */
+/*15*/	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+/*16*/	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+	FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
+};
+
+static unsigned char table_b2a_hqx[] =
+    "!\"#$%&'()*+,-012345689@ABCDEFGHIJKLMNPQRSTUVXYZ[`abcdefhijklmpqr";
+
+static unsigned short crctab_hqx[256] = {
+    0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
+    0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
+    0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
+    0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
+    0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
+    0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
+    0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
+    0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
+    0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
+    0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
+    0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
+    0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
+    0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
+    0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
+    0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
+    0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
+    0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
+    0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
+    0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
+    0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
+    0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
+    0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+    0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
+    0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
+    0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
+    0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
+    0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
+    0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
+    0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
+    0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
+    0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
+    0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0,
+};
+
+static char doc_a2b_uu[] = "(ascii) -> bin. Decode a line of uuencoded data";
+
+static PyObject *
+binascii_a2b_uu(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *ascii_data, *bin_data;
+	int leftbits = 0;
+	unsigned char this_ch;
+	unsigned int leftchar = 0;
+	PyObject *rv;
+	int ascii_len, bin_len;
+	
+	if ( !PyArg_ParseTuple(args, "s#", &ascii_data, &ascii_len) )
+		return NULL;
+
+	/* First byte: binary data length (in bytes) */
+	bin_len = (*ascii_data++ - ' ') & 077;
+	ascii_len--;
+
+	/* Allocate the buffer */
+	if ( (rv=PyString_FromStringAndSize(NULL, bin_len)) == NULL )
+		return NULL;
+	bin_data = (unsigned char *)PyString_AsString(rv);
+	
+	for( ; bin_len > 0 ; ascii_len--, ascii_data++ ) {
+		this_ch = *ascii_data;
+		if ( this_ch == '\n' || this_ch == '\r' || ascii_len <= 0) {
+			/*
+			** Whitespace. Assume some spaces got eaten at
+			** end-of-line. (We check this later)
+			*/
+			this_ch = 0;
+	        } else {
+			/* Check the character for legality */
+			if ( this_ch < ' ' || this_ch > (' ' + 63)) {
+				PyErr_SetString(Error, "Illegal char");
+				Py_DECREF(rv);
+				return NULL;
+			}
+			this_ch = (this_ch - ' ') & 077;
+		}
+		/*
+		** Shift it in on the low end, and see if there's
+		** a byte ready for output.
+		*/
+		leftchar = (leftchar << 6) | (this_ch);
+		leftbits += 6;
+		if ( leftbits >= 8 ) {
+			leftbits -= 8;
+			*bin_data++ = (leftchar >> leftbits) & 0xff;
+			leftchar &= ((1 << leftbits) - 1);
+			bin_len--;
+		}
+	}
+	/*
+	** Finally, check that if there's anything left on the line
+	** that it's whitespace only.
+	*/
+	while( ascii_len-- > 0 ) {
+		this_ch = *ascii_data++;
+		if ( this_ch != ' ' && this_ch != '\n' && this_ch != '\r' ) {
+			PyErr_SetString(Error, "Trailing garbage");
+			Py_DECREF(rv);
+			return NULL;
+		}
+	}
+	return rv;
+}
+
+static char doc_b2a_uu[] = "(bin) -> ascii. Uuencode line of data";
+	
+static PyObject *
+binascii_b2a_uu(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *ascii_data, *bin_data;
+	int leftbits = 0;
+	unsigned char this_ch;
+	unsigned int leftchar = 0;
+	PyObject *rv;
+	int bin_len;
+	
+	if ( !PyArg_ParseTuple(args, "s#", &bin_data, &bin_len) )
+		return NULL;
+	if ( bin_len > 45 ) {
+		/* The 45 is a limit that appears in all uuencode's */
+		PyErr_SetString(Error, "At most 45 bytes at once");
+		return NULL;
+	}
+
+	/* We're lazy and allocate to much (fixed up later) */
+	if ( (rv=PyString_FromStringAndSize(NULL, bin_len*2)) == NULL )
+		return NULL;
+	ascii_data = (unsigned char *)PyString_AsString(rv);
+
+	/* Store the length */
+	*ascii_data++ = ' ' + (bin_len & 077);
+	
+	for( ; bin_len > 0 || leftbits != 0 ; bin_len--, bin_data++ ) {
+		/* Shift the data (or padding) into our buffer */
+		if ( bin_len > 0 )	/* Data */
+			leftchar = (leftchar << 8) | *bin_data;
+		else			/* Padding */
+			leftchar <<= 8;
+		leftbits += 8;
+
+		/* See if there are 6-bit groups ready */
+		while ( leftbits >= 6 ) {
+			this_ch = (leftchar >> (leftbits-6)) & 0x3f;
+			leftbits -= 6;
+			*ascii_data++ = this_ch + ' ';
+		}
+	}
+	*ascii_data++ = '\n';	/* Append a courtesy newline */
+	
+	_PyString_Resize(&rv, (ascii_data - (unsigned char *)PyString_AsString(rv)));
+	return rv;
+}
+
+static char doc_a2b_hqx[] = "ascii -> bin, done. Decode .hqx coding";
+
+static PyObject *
+binascii_a2b_hqx(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *ascii_data, *bin_data;
+	int leftbits = 0;
+	unsigned char this_ch;
+	unsigned int leftchar;
+	PyObject *rv;
+	int len;
+	int done = 0;
+	
+	if ( !PyArg_ParseTuple(args, "s#", &ascii_data, &len) )
+		return NULL;
+
+	/* Allocate a string that is too big (fixed later) */
+	if ( (rv=PyString_FromStringAndSize(NULL, len)) == NULL )
+		return NULL;
+	bin_data = (unsigned char *)PyString_AsString(rv);
+
+	for( ; len > 0 ; len--, ascii_data++ ) {
+		/* Get the byte and look it up */
+		this_ch = table_a2b_hqx[*ascii_data];
+		if ( this_ch == SKIP )
+			continue;
+		if ( this_ch == FAIL ) {
+			PyErr_SetString(Error, "Illegal char");
+			Py_DECREF(rv);
+			return NULL;
+		}
+		if ( this_ch == DONE ) {
+			/* The terminating colon */
+			done = 1;
+			break;
+		}
+
+		/* Shift it into the buffer and see if any bytes are ready */
+		leftchar = (leftchar << 6) | (this_ch);
+		leftbits += 6;
+		if ( leftbits >= 8 ) {
+			leftbits -= 8;
+			*bin_data++ = (leftchar >> leftbits) & 0xff;
+			leftchar &= ((1 << leftbits) - 1);
+		}
+	}
+	
+	if ( leftbits && !done ) {
+		PyErr_SetString(Incomplete,
+				"String has incomplete number of bytes");
+		Py_DECREF(rv);
+		return NULL;
+	}
+	_PyString_Resize(&rv, (bin_data - (unsigned char *)PyString_AsString(rv)));
+	if ( rv )
+		return Py_BuildValue("Oi", rv, done);
+	return NULL;
+}
+
+static char doc_rlecode_hqx[] = "Binhex RLE-code binary data";
+
+static PyObject *
+binascii_rlecode_hqx(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *in_data, *out_data;
+	PyObject *rv;
+	unsigned char ch;
+	int in, inend, len;
+	
+	if ( !PyArg_ParseTuple(args, "s#", &in_data, &len) )
+		return NULL;
+
+	/* Worst case: output is twice as big as input (fixed later) */
+	if ( (rv=PyString_FromStringAndSize(NULL, len*2)) == NULL )
+		return NULL;
+	out_data = (unsigned char *)PyString_AsString(rv);
+	
+	for( in=0; in<len; in++) {
+		ch = in_data[in];
+		if ( ch == RUNCHAR ) {
+			/* RUNCHAR. Escape it. */
+			*out_data++ = RUNCHAR;
+			*out_data++ = 0;
+		} else {
+			/* Check how many following are the same */
+			for(inend=in+1;
+			    inend<len && in_data[inend] == ch &&
+			        inend < in+255;
+			    inend++) ;
+			if ( inend - in > 3 && inend-in != RUNCHAR ) {
+				/* More than 3 in a row. Output RLE.
+				** The special case of exactly 0x90 repeats will result in a single
+				** byte now and a 0x8f repeat next time around
+				*/
+				*out_data++ = ch;
+				*out_data++ = RUNCHAR;
+				*out_data++ = inend-in;
+				in = inend-1;
+			} else {
+				/* Less than 3. Output the byte itself */
+				*out_data++ = ch;
+			}
+		}
+	}
+	_PyString_Resize(&rv, (out_data - (unsigned char *)PyString_AsString(rv)));
+	return rv;
+}
+
+static char doc_b2a_hqx[] = "Encode .hqx data";
+	
+static PyObject *
+binascii_b2a_hqx(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *ascii_data, *bin_data;
+	int leftbits = 0;
+	unsigned char this_ch;
+	unsigned int leftchar;
+	PyObject *rv;
+	int len;
+	
+	if ( !PyArg_ParseTuple(args, "s#", &bin_data, &len) )
+		return NULL;
+
+	/* Allocate a buffer that is at least large enough */
+	if ( (rv=PyString_FromStringAndSize(NULL, len*2)) == NULL )
+		return NULL;
+	ascii_data = (unsigned char *)PyString_AsString(rv);
+	
+	for( ; len > 0 ; len--, bin_data++ ) {
+		/* Shift into our buffer, and output any 6bits ready */
+		leftchar = (leftchar << 8) | *bin_data;
+		leftbits += 8;
+		while ( leftbits >= 6 ) {
+			this_ch = (leftchar >> (leftbits-6)) & 0x3f;
+			leftbits -= 6;
+			*ascii_data++ = table_b2a_hqx[this_ch];
+		}
+	}
+	/* Output a possible runt byte */
+	if ( leftbits ) {
+		leftchar <<= (6-leftbits);
+		*ascii_data++ = table_b2a_hqx[leftchar & 0x3f];
+	}
+	_PyString_Resize(&rv, (ascii_data - (unsigned char *)PyString_AsString(rv)));
+	return rv;
+}
+
+static char doc_rledecode_hqx[] = "Decode hexbin RLE-coded string";
+	
+static PyObject *
+binascii_rledecode_hqx(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *in_data, *out_data;
+	unsigned char in_byte, in_repeat;
+	PyObject *rv;
+	int in_len, out_len, out_len_left;
+
+	if ( !PyArg_ParseTuple(args, "s#", &in_data, &in_len) )
+		return NULL;
+
+	/* Empty string is a special case */
+	if ( in_len == 0 )
+		return Py_BuildValue("s", "");
+
+	/* Allocate a buffer of reasonable size. Resized when needed */
+	out_len = in_len*2;
+	if ( (rv=PyString_FromStringAndSize(NULL, out_len)) == NULL )
+		return NULL;
+	out_len_left = out_len;
+	out_data = (unsigned char *)PyString_AsString(rv);
+
+	/*
+	** We need two macros here to get/put bytes and handle
+	** end-of-buffer for input and output strings.
+	*/
+#define INBYTE(b) \
+    do { \
+	if ( --in_len < 0 ) { \
+		PyErr_SetString(Incomplete, ""); \
+	        Py_DECREF(rv); \
+		return NULL; \
+	} \
+	b = *in_data++; \
+    } while(0)
+	    
+#define OUTBYTE(b) \
+    do { \
+	if ( --out_len_left < 0 ) { \
+		_PyString_Resize(&rv, 2*out_len); \
+		if ( rv == NULL ) return NULL; \
+		out_data = (unsigned char *)PyString_AsString(rv) + out_len; \
+		out_len_left = out_len; \
+		out_len = out_len * 2; \
+	} \
+	*out_data++ = b; \
+    } while(0)
+
+	/*
+	** Handle first byte separately (since we have to get angry
+	** in case of an orphaned RLE code).
+	*/
+	INBYTE(in_byte);
+
+	if (in_byte == RUNCHAR) {
+		INBYTE(in_repeat);
+		if (in_repeat != 0) {
+			/* Note Error, not Incomplete (which is at the end
+			** of the string only). This is a programmer error.
+			*/
+			PyErr_SetString(Error, "Orphaned RLE code at start");
+			Py_DECREF(rv);
+			return NULL;
+		}
+		OUTBYTE(RUNCHAR);
+	} else {
+		OUTBYTE(in_byte);
+	}
+	
+	while( in_len > 0 ) {
+		INBYTE(in_byte);
+
+		if (in_byte == RUNCHAR) {
+			INBYTE(in_repeat);
+			if ( in_repeat == 0 ) {
+				/* Just an escaped RUNCHAR value */
+				OUTBYTE(RUNCHAR);
+			} else {
+				/* Pick up value and output a sequence of it */
+				in_byte = out_data[-1];
+				while ( --in_repeat > 0 )
+					OUTBYTE(in_byte);
+			}
+		} else {
+			/* Normal byte */
+			OUTBYTE(in_byte);
+		}
+	}
+	_PyString_Resize(&rv, (out_data - (unsigned char *)PyString_AsString(rv)));
+	return rv;
+}
+
+static char doc_crc_hqx[] = "(data, oldcrc) -> newcrc. Compute hqx CRC incrementally";
+
+static PyObject *
+binascii_crc_hqx(self, args)
+	PyObject *self;
+	PyObject *args;
+{
+	unsigned char *bin_data;
+	unsigned int crc;
+	int len;
+	
+	if ( !PyArg_ParseTuple(args, "s#i", &bin_data, &len, &crc) )
+		return NULL;
+
+	while(len--) {
+		crc=((crc<<8)&0xff00)^crctab_hqx[((crc>>8)&0xff)^*bin_data++];
+	}
+
+	return Py_BuildValue("i", crc);
+}
+
+/* List of functions defined in the module */
+
+static struct PyMethodDef binascii_module_methods[] = {
+	{"a2b_uu",		binascii_a2b_uu,	1,	doc_a2b_uu},
+	{"b2a_uu",		binascii_b2a_uu,	1,	doc_b2a_uu},
+	{"a2b_hqx",		binascii_a2b_hqx,	1,	doc_a2b_hqx},
+	{"b2a_hqx",		binascii_b2a_hqx,	1,	doc_b2a_hqx},
+	{"rlecode_hqx",		binascii_rlecode_hqx,	1,
+		 doc_rlecode_hqx},
+	{"rledecode_hqx",	binascii_rledecode_hqx,	1,
+		 doc_rledecode_hqx},
+	{"crc_hqx",		binascii_crc_hqx,	1,	doc_crc_hqx},
+	{NULL,			NULL}		/* sentinel */
+};
+
+
+/* Initialization function for the module (*must* be called initbinascii) */
+static char doc_binascii[] = "Conversion between binary data and ASCII";
+
+void
+initbinascii()
+{
+	PyObject *m, *d, *x;
+
+	/* Create the module and add the functions */
+	m = Py_InitModule("binascii", binascii_module_methods);
+
+	d = PyModule_GetDict(m);
+	x = PyString_FromString(doc_binascii);
+	PyDict_SetItemString(d, "__doc__", x);
+
+	Error = PyString_FromString("binascii.Error");
+	PyDict_SetItemString(d, "Error", Error);
+	Incomplete = PyString_FromString("binascii.Incomplete");
+	PyDict_SetItemString(d, "Incomplete", Incomplete);
+
+	/* Check for errors */
+	if (PyErr_Occurred())
+		Py_FatalError("can't initialize module binascii");
+}