lib/cpp/src/protocol/TBase64Utils.cpp

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#include "TBase64Utils.h"

#include <boost/static_assert.hpp>

using std::string;

namespace apache { namespace thrift { namespace protocol {


static const uint8_t *kBase64EncodeTable = (const uint8_t *)
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

void  base64_encode(const uint8_t *in, uint32_t len, uint8_t *buf) {
  buf[0] = kBase64EncodeTable[(in[0] >> 2) & 0x3F];
  if (len == 3) {
    buf[1] = kBase64EncodeTable[((in[0] << 4) + (in[1] >> 4)) & 0x3f];
    buf[2] = kBase64EncodeTable[((in[1] << 2) + (in[2] >> 6)) & 0x3f];
    buf[3] = kBase64EncodeTable[in[2] & 0x3f];
  } else if (len == 2) {
    buf[1] = kBase64EncodeTable[((in[0] << 4) + (in[1] >> 4)) & 0x3f];
    buf[2] = kBase64EncodeTable[(in[1] << 2) & 0x3f];
  } else  { // len == 1
    buf[1] = kBase64EncodeTable[(in[0] << 4) & 0x3f];
  }
}

static const uint8_t kBase64DecodeTable[256] ={
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3e,0xff,0xff,0xff,0x3f,
0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,
0x0f,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0xff,0xff,0xff,0xff,0xff,
0xff,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,
0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,0x30,0x31,0x32,0x33,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
};

void base64_decode(uint8_t *buf, uint32_t len) {
  buf[0] = (kBase64DecodeTable[buf[0]] << 2) |
           (kBase64DecodeTable[buf[1]] >> 4);
  if (len > 2) {
    buf[1] = ((kBase64DecodeTable[buf[1]] << 4) & 0xf0) |
              (kBase64DecodeTable[buf[2]] >> 2);
    if (len > 3) {
      buf[2] = ((kBase64DecodeTable[buf[2]] << 6) & 0xc0) |
                (kBase64DecodeTable[buf[3]]);
    }
  }
}


}}} // apache::thrift::protocol