/*** 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.** base64:**      Line breaks are insignificant, but lines are at most 76 chars**      each char encodes 6 bits, in similar order as uucode/hqx. Encoding**      is done via a table.**      Short binary data is filled (in ASCII) with '='.** 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.**** Added support for quoted-printable encoding, based on rfc 1521 et al** quoted-printable encoding specifies that non printable characters (anything** below 32 and above 126) be encoded as =XX where XX is the hexadecimal value** of the character.  It also specifies some other behavior to enable 8bit data** in a mail message with little difficulty (maximum line sizes, protecting** some cases of whitespace, etc).**** Brandon Long, September 2001.*/ #define PY_SSIZE_T_CLEAN #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 char table_a2b_base64[] = {	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,	52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1, 0,-1,-1, /* Note PAD->0 */	-1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,	15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,	-1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,	41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1}; #define BASE64_PAD '=' /* Max binary chunk size; limited only by available memory */#define BASE64_MAXBIN (INT_MAX/2 - sizeof(PyStringObject) - 3) static unsigned char table_b2a_base64[] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";   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,}; PyDoc_STRVAR(doc_a2b_uu, "(ascii) -> bin. Decode a line of uuencoded data"); static PyObject *binascii_a2b_uu(PyObject *self, PyObject *args){	unsigned char *ascii_data, *bin_data;	int leftbits = 0;	unsigned char this_ch;	unsigned int leftchar = 0;	PyObject *rv;	Py_ssize_t ascii_len, bin_len; 	if ( !PyArg_ParseTuple(args, "t#:a2b_uu", &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++ ) {		/* XXX is it really best to add NULs if there's no more data */		this_ch = (ascii_len > 0) ? *ascii_data : 0;		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			** The 64 in stead of the expected 63 is because			** there are a few uuencodes out there that use			** '`' as zero instead of space.			*/			if ( this_ch < ' ' || this_ch > (' ' + 64)) {				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++;		/* Extra '`' may be written as padding in some cases */		if ( this_ch != ' ' && this_ch != ' '+64 &&		     this_ch != '\n' && this_ch != '\r' ) {			PyErr_SetString(Error, "Trailing garbage");			Py_DECREF(rv);			return NULL;		}	}	return rv;} PyDoc_STRVAR(doc_b2a_uu, "(bin) -> ascii. Uuencode line of data"); static PyObject *binascii_b2a_uu(PyObject *self, PyObject *args){	unsigned char *ascii_data, *bin_data;	int leftbits = 0;	unsigned char this_ch;	unsigned int leftchar = 0;	PyObject *rv;	Py_ssize_t bin_len; 	if ( !PyArg_ParseTuple(args, "s#:b2a_uu", &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+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 intbinascii_find_valid(unsigned char *s, Py_ssize_t slen, int num){	/* Finds & returns the (num+1)th	** valid character for base64, or -1 if none.	*/ 	int ret = -1;	unsigned char c, b64val; 	while ((slen > 0) && (ret == -1)) {		c = *s;		b64val = table_a2b_base64[c & 0x7f];		if ( ((c <= 0x7f) && (b64val != (unsigned char)-1)) ) {			if (num == 0)				ret = *s;			num--;		} 		s++;		slen--;	}	return ret;} PyDoc_STRVAR(doc_a2b_base64, "(ascii) -> bin. Decode a line of base64 data"); static PyObject *binascii_a2b_base64(PyObject *self, PyObject *args){	unsigned char *ascii_data, *bin_data;	int leftbits = 0;	unsigned char this_ch;	unsigned int leftchar = 0;	PyObject *rv;	Py_ssize_t ascii_len, bin_len;	int quad_pos = 0; 	if ( !PyArg_ParseTuple(args, "t#:a2b_base64", &ascii_data, &ascii_len) )		return NULL; 	bin_len = ((ascii_len+3)/4)*3; /* Upper bound, corrected later */ 	/* Allocate the buffer */	if ( (rv=PyString_FromStringAndSize(NULL, bin_len)) == NULL )		return NULL;	bin_data = (unsigned char *)PyString_AsString(rv);	bin_len = 0; 	for( ; ascii_len > 0; ascii_len--, ascii_data++) {		this_ch = *ascii_data; 		if (this_ch > 0x7f ||		    this_ch == '\r' || this_ch == '\n' || this_ch == ' ')			continue; 		/* Check for pad sequences and ignore		** the invalid ones.		*/		if (this_ch == BASE64_PAD) {			if ( (quad_pos < 2) ||			     ((quad_pos == 2) &&			      (binascii_find_valid(ascii_data, ascii_len, 1)			       != BASE64_PAD)) )			{				continue;			}			else {				/* A pad sequence means no more input.				** We've already interpreted the data				** from the quad at this point.				*/				leftbits = 0;				break;			}		} 		this_ch = table_a2b_base64[*ascii_data];		if ( this_ch == (unsigned char) -1 )			continue; 		/*		** Shift it in on the low end, and see if there's		** a byte ready for output.		*/		quad_pos = (quad_pos + 1) & 0x03;		leftchar = (leftchar << 6) | (this_ch);		leftbits += 6; 		if ( leftbits >= 8 ) {			leftbits -= 8;			*bin_data++ = (leftchar >> leftbits) & 0xff;			bin_len++;			leftchar &= ((1 << leftbits) - 1);		} 	} 	if (leftbits != 0) {		PyErr_SetString(Error, "Incorrect padding");		Py_DECREF(rv);		return NULL;	} 	/* And set string size correctly. If the result string is empty	** (because the input was all invalid) return the shared empty	** string instead; _PyString_Resize() won't do this for us.	*/	if (bin_len > 0)		_PyString_Resize(&rv, bin_len);	else {		Py_DECREF(rv);		rv = PyString_FromString("");	}	return rv;} PyDoc_STRVAR(doc_b2a_base64, "(bin) -> ascii. Base64-code line of data"); static PyObject *binascii_b2a_base64(PyObject *self, PyObject *args){	unsigned char *ascii_data, *bin_data;	int leftbits = 0;	unsigned char this_ch;	unsigned int leftchar = 0;	PyObject *rv;	Py_ssize_t bin_len; 	if ( !PyArg_ParseTuple(args, "s#:b2a_base64", &bin_data, &bin_len) )		return NULL;	if ( bin_len > BASE64_MAXBIN ) {		PyErr_SetString(Error, "Too much data for base64 line");		return NULL;	} 	/* We're lazy and allocate too much (fixed up later).	   "+3" leaves room for up to two pad characters and a trailing	   newline.  Note that 'b' gets encoded as 'Yg==\n' (1 in, 5 out). */	if ( (rv=PyString_FromStringAndSize(NULL, bin_len*2 + 3)) == NULL )		return NULL;	ascii_data = (unsigned char *)PyString_AsString(rv); 	for( ; bin_len > 0 ; bin_len--, bin_data++ ) {		/* Shift the data into our buffer */		leftchar = (leftchar << 8) | *bin_data;		leftbits += 8; 		/* See if there are 6-bit groups ready */		while ( leftbits >= 6 ) {			this_ch = (leftchar >> (leftbits-6)) & 0x3f;			leftbits -= 6;			*ascii_data++ = table_b2a_base64[this_ch];		}	}	if ( leftbits == 2 ) {		*ascii_data++ = table_b2a_base64[(leftchar&3) << 4];		*ascii_data++ = BASE64_PAD;		*ascii_data++ = BASE64_PAD;	} else if ( leftbits == 4 ) {		*ascii_data++ = table_b2a_base64[(leftchar&0xf) << 2];		*ascii_data++ = BASE64_PAD;	}	*ascii_data++ = '\n';	/* Append a courtesy newline */ 	_PyString_Resize(&rv, (ascii_data -			       (unsigned char *)PyString_AsString(rv)));	return rv;} PyDoc_STRVAR(doc_a2b_hqx, "ascii -> bin, done. Decode .hqx coding"); static PyObject *binascii_a2b_hqx(PyObject *self, PyObject *args){	unsigned char *ascii_data, *bin_data;	int leftbits = 0;	unsigned char this_ch;	unsigned int leftchar = 0;	PyObject *rv;	Py_ssize_t len;	int done = 0; 	if ( !PyArg_ParseTuple(args, "t#:a2b_hqx", &ascii_data, &len) )		return NULL; 	/* Allocate a string that is too big (fixed later) 	   Add two to the initial length to prevent interning which	   would preclude subsequent resizing.  */	if ( (rv=PyString_FromStringAndSize(NULL, len+2)) == NULL )		return NULL;	bin_data = (unsigned char *)PyString_AsString(rv);

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