lib/cpp/src/thrift/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 <thrift/protocol/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) & 0x30) | ((in[1] >> 4) & 0x0f)];
    buf[2] = kBase64EncodeTable[((in[1] << 2) & 0x3c) | ((in[2] >> 6) & 0x03)];
    buf[3] = kBase64EncodeTable[in[2] & 0x3f];
  } else if (len == 2) {
    buf[1] = kBase64EncodeTable[((in[0] << 4) & 0x30) | ((in[1] >> 4) & 0x0f)];
    buf[2] = kBase64EncodeTable[(in[1] << 2) & 0x3c];
  } else { // len == 1
    buf[1] = kBase64EncodeTable[(in[0] << 4) & 0x30];
  }
}

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