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authorSebastian Holtermann <sebholt@xwmw.org>2016-09-01 11:08:18 (GMT)
committerBrad King <brad.king@kitware.com>2016-09-02 13:18:59 (GMT)
commitb481ddb3df21e02e16038854ec7d256601717018 (patch)
tree4e2541ab88950213a938af7e5936492842fa98d1 /Source/cmBase32.cxx
parent0c46750d2c4cee401f1cda047a71b0e349678077 (diff)
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Add cmBase32Encoder class
Diffstat (limited to 'Source/cmBase32.cxx')
-rw-r--r--Source/cmBase32.cxx108
1 files changed, 108 insertions, 0 deletions
diff --git a/Source/cmBase32.cxx b/Source/cmBase32.cxx
new file mode 100644
index 0000000..ce5c99b
--- /dev/null
+++ b/Source/cmBase32.cxx
@@ -0,0 +1,108 @@
+/*============================================================================
+ CMake - Cross Platform Makefile Generator
+ Copyright 2016 Sebastian Holtermann <sebholt@xwmw.org>
+
+ Distributed under the OSI-approved BSD License (the "License");
+ see accompanying file Copyright.txt for details.
+
+ This software is distributed WITHOUT ANY WARRANTY; without even the
+ implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ See the License for more information.
+============================================================================*/
+#include "cmBase32.h"
+
+// -- Static functions
+
+static const unsigned char Base32EncodeTable[33] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+inline unsigned char Base32EncodeChar(int schar)
+{
+ return Base32EncodeTable[schar];
+}
+
+void Base32Encode5(const unsigned char src[5], char dst[8])
+{
+ // [0]:5 bits
+ dst[0] = Base32EncodeChar((src[0] >> 3) & 0x1F);
+ // [0]:3 bits + [1]:2 bits
+ dst[1] = Base32EncodeChar(((src[0] << 2) & 0x1C) + ((src[1] >> 6) & 0x03));
+ // [1]:5 bits
+ dst[2] = Base32EncodeChar((src[1] >> 1) & 0x1F);
+ // [1]:1 bit + [2]:4 bits
+ dst[3] = Base32EncodeChar(((src[1] << 4) & 0x10) + ((src[2] >> 4) & 0x0F));
+ // [2]:4 bits + [3]:1 bit
+ dst[4] = Base32EncodeChar(((src[2] << 1) & 0x1E) + ((src[3] >> 7) & 0x01));
+ // [3]:5 bits
+ dst[5] = Base32EncodeChar((src[3] >> 2) & 0x1F);
+ // [3]:2 bits + [4]:3 bit
+ dst[6] = Base32EncodeChar(((src[3] << 3) & 0x18) + ((src[4] >> 5) & 0x07));
+ // [4]:5 bits
+ dst[7] = Base32EncodeChar((src[4] << 0) & 0x1F);
+}
+
+// -- Class methods
+
+cmBase32Encoder::cmBase32Encoder()
+{
+}
+
+cmBase32Encoder::~cmBase32Encoder()
+{
+}
+
+std::string cmBase32Encoder::encodeString(const unsigned char* input,
+ size_t len, bool padding)
+{
+ std::string res;
+
+ static const size_t blockSize = 5;
+ static const size_t bufferSize = 8;
+ char buffer[bufferSize];
+
+ const unsigned char* end = input + len;
+ while ((input + blockSize) <= end) {
+ Base32Encode5(input, buffer);
+ res.append(buffer, bufferSize);
+ input += blockSize;
+ }
+
+ size_t remain(end - input);
+ if (remain != 0) {
+ // Temporary source buffer filled up with 0s
+ unsigned char extended[blockSize];
+ for (size_t ii = 0; ii != remain; ++ii) {
+ extended[ii] = input[ii];
+ }
+ for (size_t ii = remain; ii != blockSize; ++ii) {
+ extended[ii] = 0;
+ }
+
+ Base32Encode5(extended, buffer);
+ size_t numPad(0);
+ switch (remain) {
+ case 1:
+ numPad = 6;
+ break;
+ case 2:
+ numPad = 4;
+ break;
+ case 3:
+ numPad = 3;
+ break;
+ case 4:
+ numPad = 1;
+ break;
+ default:
+ break;
+ }
+ res.append(buffer, bufferSize - numPad);
+ if (padding) {
+ for (size_t ii = 0; ii != numPad; ++ii) {
+ res.push_back(paddingChar);
+ }
+ }
+ }
+
+ return res;
+}