--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lphobos/std/base64.d	Fri Dec 28 23:52:40 2007 +0100
@@ -0,0 +1,293 @@
+/**
+ * Encodes/decodes MIME base64 data.
+ *
+ * Macros:
+ *	WIKI=Phobos/StdBase64
+ * References:
+ *	<a href="http://en.wikipedia.org/wiki/Base64">Wikipedia Base64</a>$(BR)
+ *	<a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>$(BR)
+ */
+
+
+/* base64.d
+ * Modified from C. Miller's version, his copyright is below.
+ */
+
+/*
+	Copyright (C) 2004 Christopher E. Miller
+	
+	This software is provided 'as-is', without any express or implied
+	warranty.  In no event will the authors be held liable for any damages
+	arising from the use of this software.
+	
+	Permission is granted to anyone to use this software for any purpose,
+	including commercial applications, and to alter it and redistribute it
+	freely, subject to the following restrictions:
+	
+	1. The origin of this software must not be misrepresented; you must not
+	   claim that you wrote the original software. If you use this software
+	   in a product, an acknowledgment in the product documentation would be
+	   appreciated but is not required.
+	2. Altered source versions must be plainly marked as such, and must not be
+	   misrepresented as being the original software.
+	3. This notice may not be removed or altered from any source distribution.
+*/
+
+module std.base64;
+
+/**
+ */
+
+class Base64Exception: Exception
+{
+	this(char[] msg)
+	{
+		super(msg);
+	}
+}
+
+
+/**
+ */
+
+class Base64CharException: Base64Exception
+{
+	this(char[] msg)
+	{
+		super(msg);
+	}
+}
+
+
+const char[] array = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+
+/**
+ * Returns the number of bytes needed to encode a string of length slen.
+ */
+
+uint encodeLength(uint slen)
+{
+	uint result;
+	result = slen / 3;
+	if(slen % 3)
+		result++;
+	return result * 4;
+}
+
+/**
+ * Encodes str[] and places the result in buf[].
+ * Params:
+ *	str = string to encode
+ * 	buf = destination buffer, must be large enough for the result.
+ * Returns:
+ *	slice into buf[] representing encoded result
+ */
+
+char[] encode(char[] str, char[] buf)
+in
+{
+	assert(buf.length >= encodeLength(str.length));
+}
+body
+{
+	if(!str.length)
+		return buf[0 .. 0];
+	
+	uint stri;
+	uint strmax = str.length / 3;
+	uint strleft = str.length % 3;
+	uint x;
+	char* sp, bp;
+	
+	bp = &buf[0];
+	sp = &str[0];
+	for(stri = 0; stri != strmax; stri++)
+	{
+		x = (sp[0] << 16) | (sp[1] << 8) | (sp[2]);
+		sp+= 3;
+		*bp++ = array[(x & 0b11111100_00000000_00000000) >> 18];
+		*bp++ = array[(x & 0b00000011_11110000_00000000) >> 12];
+		*bp++ = array[(x & 0b00000000_00001111_11000000) >> 6];
+		*bp++ = array[(x & 0b00000000_00000000_00111111)];
+	}
+	
+	switch(strleft)
+	{
+		case 2:
+			x = (sp[0] << 16) | (sp[1] << 8);
+			sp += 2;
+			*bp++ = array[(x & 0b11111100_00000000_00000000) >> 18];
+			*bp++ = array[(x & 0b00000011_11110000_00000000) >> 12];
+			*bp++ = array[(x & 0b00000000_00001111_11000000) >> 6];
+			*bp++ = '=';
+			break;
+		
+		case 1:
+			x = *sp++ << 16;
+			*bp++ = array[(x & 0b11111100_00000000_00000000) >> 18];
+			*bp++ = array[(x & 0b00000011_11110000_00000000) >> 12];
+			*bp++ = '=';
+			*bp++ = '=';
+			break;
+		
+		case 0:
+			break;
+
+		default:
+			assert(0);
+	}
+	
+	return buf[0 .. (bp - &buf[0])];
+}
+
+
+/**
+ * Encodes str[] and returns the result.
+ */
+
+char[] encode(char[] str)
+{
+	return encode(str, new char[encodeLength(str.length)]);
+}
+
+
+unittest
+{
+	assert(encode("f") == "Zg==");
+	assert(encode("fo") == "Zm8=");
+	assert(encode("foo") == "Zm9v");
+	assert(encode("foos") == "Zm9vcw==");
+	assert(encode("all your base64 are belong to foo") == "YWxsIHlvdXIgYmFzZTY0IGFyZSBiZWxvbmcgdG8gZm9v");
+}
+
+
+/**
+ * Returns the number of bytes needed to decode an encoded string of this
+ * length.
+ */
+uint decodeLength(uint elen)
+{
+	return elen / 4 * 3;
+}
+
+
+/**
+ * Decodes str[] and places the result in buf[].
+ * Params:
+ *	str = string to encode
+ * 	buf = destination buffer, must be large enough for the result.
+ * Returns:
+ *	slice into buf[] representing encoded result
+ * Errors:
+ *	Throws Base64Exception on invalid base64 encoding in estr[].
+ *	Throws Base64CharException on invalid base64 character in estr[].
+ */
+char[] decode(char[] estr, char[] buf)
+in
+{
+	assert(buf.length + 2 >= decodeLength(estr.length)); //account for '=' padding
+}
+body
+{
+	void badc(char ch)
+	{
+		throw new Base64CharException("Invalid base64 character '" ~ (&ch)[0 .. 1] ~ "'");
+	}
+	
+	
+	uint arrayIndex(char ch)
+	out(result)
+	{
+		assert(ch == array[result]);
+	}
+	body
+	{
+		if(ch >= 'A' && ch <= 'Z')
+			return ch - 'A';
+		if(ch >= 'a' && ch <= 'z')
+			return 'Z' - 'A' + 1 + ch - 'a';
+		if(ch >= '0' && ch <= '9')
+			return 'Z' - 'A' + 1 + 'z' - 'a' + 1 + ch - '0';
+		if(ch == '+')
+			return 'Z' - 'A' + 1 + 'z' - 'a' + 1 + '9' - '0' + 1;
+		if(ch == '/')
+			return 'Z' - 'A' + 1 + 'z' - 'a' + 1 + '9' - '0' + 1 + 1;
+		badc(ch);
+		assert(0);
+	}
+	
+	
+	if(!estr.length)
+		return buf[0 .. 0];
+	
+	if(estr.length % 4)
+		throw new Base64Exception("Invalid encoded base64 string");
+	
+	uint estri;
+	uint estrmax = estr.length / 4;
+	uint x;
+	char* sp, bp;
+	char ch;
+	
+	sp = &estr[0];
+	bp = &buf[0];
+	for(estri = 0; estri != estrmax; estri++)
+	{
+		x = arrayIndex(sp[0]) << 18 | arrayIndex(sp[1]) << 12;
+		sp += 2;
+
+		ch = *sp++;
+		if(ch == '=')
+		{
+			if(*sp++ != '=')
+				badc('=');
+			*bp++ = cast(char) (x >> 16);
+			break;
+		}
+		x |= arrayIndex(ch) << 6;
+		
+		ch = *sp++;
+		if(ch == '=')
+		{
+			*bp++ = cast(char) (x >> 16);
+			*bp++ = cast(char) ((x >> 8) & 0xFF);
+			break;
+		}
+		x |= arrayIndex(ch);
+		
+		*bp++ = cast(char) (x >> 16);
+		*bp++ = cast(char) ((x >> 8) & 0xFF);
+		*bp++ = cast(char) (x & 0xFF);
+	}
+	
+	return buf[0 .. (bp - &buf[0])];
+}
+
+/**
+ * Decodes estr[] and returns the result.
+ * Errors:
+ *	Throws Base64Exception on invalid base64 encoding in estr[].
+ *	Throws Base64CharException on invalid base64 character in estr[].
+ */
+
+char[] decode(char[] estr)
+{
+	return decode(estr, new char[decodeLength(estr.length)]);
+}
+
+
+unittest
+{
+	assert(decode(encode("f")) == "f");
+	assert(decode(encode("fo")) == "fo");
+	assert(decode(encode("foo")) == "foo");
+	assert(decode(encode("foos")) == "foos");
+	assert(decode(encode("all your base64 are belong to foo")) == "all your base64 are belong to foo");
+	
+	assert(decode(encode("testing some more")) == "testing some more");
+	assert(decode(encode("asdf jkl;")) == "asdf jkl;");
+	assert(decode(encode("base64 stuff")) == "base64 stuff");
+	assert(decode(encode("\1\2\3\4\5\6\7foo\7\6\5\4\3\2\1!")) == "\1\2\3\4\5\6\7foo\7\6\5\4\3\2\1!");
+}
+