Imported existing code

indra/llcommon/llbase32.cpp

@@ -0,0 +1,244 @@
+/** 
+ * @file llbase32.cpp
+ * @brief base32 encoding that returns a std::string
+ * @author James Cook
+ *
+ * Based on code from bitter
+ * http://ghostwhitecrab.com/bitter/
+ *
+ * Some parts of this file are:
+ * $LicenseInfo:firstyear=2007&license=viewergpl$
+ * 
+ * Copyright (c) 2007-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+/**
+ * Copyright (c) 2006 Christian Biere <christianbiere@gmx.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the authors nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "linden_common.h"
+
+#include "llbase32.h"
+
+#include <string>
+
+// bitter - base32.c starts here
+
+/*
+ * See RFC 3548 for details about Base 32 encoding:
+ *  http://www.faqs.org/rfcs/rfc3548.html
+ */
+
+static const char base32_alphabet[32] = {
+  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+  'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+  'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+  'Y', 'Z', '2', '3', '4', '5', '6', '7'
+};
+
+size_t
+base32_encode(char *dst, size_t size, const void *data, size_t len)
+{
+  size_t i = 0;
+  const U8 *p = (const U8*)data;
+  const char *end = &dst[size];
+  char *q = dst;
+
+  do {
+    size_t j, k;
+    U8 x[5];
+    char s[8];
+
+    switch (len - i) {
+    case 4: k = 7; break;
+    case 3: k = 5; break;
+    case 2: k = 3; break;
+    case 1: k = 2; break;
+    default:
+      k = 8;
+    }
+
+    for (j = 0; j < 5; j++)
+      x[j] = i < len ? p[i++] : 0;
+
+/*
+  +-------+-----------+--------+
+  | target| source    | source |
+  | byte  | bits      | byte   |
+  +-------+-----------+--------+
+  |     0 | 7 6 5 4 3 | 0      |
+  |     1 | 2 1 0 7 6 | 0-1    |
+  |     2 | 5 4 3 2 1 | 1      |
+  |     3 | 0 7 6 5 4 | 1-2    |
+  |     4 | 3 2 1 0 7 | 2-3    |
+  |     5 | 6 5 4 3 2 | 3      |
+  |     6 | 1 0 7 6 5 | 3-4    |
+  |     7 | 4 3 2 1 0 | 4      |
+  +-------+-----------+--------+
+  
+*/
+    
+    s[0] =  (x[0] >> 3);
+    s[1] = ((x[0] & 0x07) << 2) | (x[1] >> 6);
+    s[2] =  (x[1] >> 1) & 0x1f;
+    s[3] = ((x[1] & 0x01) << 4) | (x[2] >> 4);
+    s[4] = ((x[2] & 0x0f) << 1) | (x[3] >> 7);
+    s[5] =  (x[3] >> 2) & 0x1f;
+    s[6] = ((x[3] & 0x03) << 3) | (x[4] >> 5);
+    s[7] =   x[4] & 0x1f;
+
+    for (j = 0; j < k && q != end; j++)
+      *q++ = base32_alphabet[(U8) s[j]];
+
+  } while (i < len);
+
+  return q - dst;
+}
+
+/* *TODO: Implement base32 encode.
+
+static inline int
+ascii_toupper(int c)
+{
+  return c >= 97 && c <= 122 ? c - 32 : c;
+}
+
+static inline int
+ascii_tolower(int c)
+{
+  return c >= 65 && c <= 90 ? c + 32 : c;
+}
+
+
+static char base32_map[(unsigned char) -1];
+
+size_t
+base32_decode(char *dst, size_t size, const void *data, size_t len)
+{
+  const char *end = &dst[size];
+  const unsigned char *p = data;
+  char *q = dst;
+  size_t i;
+  unsigned max_pad = 3;
+
+  if (0 == base32_map[0]) {
+    for (i = 0; i < LL_ARRAY_SIZE(base32_map); i++) {
+      const char *x;
+      
+      x = memchr(base32_alphabet, ascii_toupper(i), sizeof base32_alphabet);
+      base32_map[i] = x ? (x - base32_alphabet) : (unsigned char) -1;
+    }
+  }
+  
+  for (i = 0; i < len && max_pad > 0; i++) {
+    unsigned char c;
+    char s[8];
+    size_t j;
+
+    c = p[i];
+    if ('=' == c) {
+      max_pad--;
+      c = 0;
+    } else {
+      c = base32_map[c];
+      if ((unsigned char) -1 == c) {
+        return -1;
+      }
+    }
+
+    j = i % LL_ARRAY_SIZE(s);
+    s[j] = c;
+
+    if (7 == j) {
+      char b[5];
+
+      b[0] = ((s[0] << 3) & 0xf8) | ((s[1] >> 2) & 0x07);
+      b[1] = ((s[1] & 0x03) << 6) | ((s[2] & 0x1f) << 1) | ((s[3] >> 4) & 1);
+      b[2] = ((s[3] & 0x0f) << 4) | ((s[4] >> 1) & 0x0f);
+      b[3] = ((s[4] & 1) << 7) | ((s[5] & 0x1f) << 2) | ((s[6] >> 3) & 0x03);
+      b[4] = ((s[6] & 0x07) << 5) | (s[7] & 0x1f);
+
+      for (j = 0; j < LL_ARRAY_SIZE(b); j++) {
+        if (q != end)
+          *q = b[j];
+        q++;
+      }
+    }
+  }
+
+  return q - dst;
+}
+*/
+
+
+// The following is
+// Copyright (c) 2007-$CurrentYear$, Linden Research, Inc.
+// static
+std::string LLBase32::encode(const U8* input, size_t input_size)
+{
+	std::string output;
+	if (input)
+	{
+		// Each 5 byte chunk of input is represented by an
+		// 8 byte chunk of output.
+		size_t input_chunks = (input_size + 4) / 5;
+		size_t output_size = input_chunks * 8;
+
+		output.resize(output_size);
+
+		size_t encoded = base32_encode(&output[0], output_size, input, input_size);
+
+		llinfos << "encoded " << encoded << " into buffer of size "
+			<< output_size << llendl;
+	}
+	return output;
+}