diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/strings/internal/escaping.cc')
| -rw-r--r-- | third_party/abseil_cpp/absl/strings/internal/escaping.cc | 180 |
1 files changed, 0 insertions, 180 deletions
diff --git a/third_party/abseil_cpp/absl/strings/internal/escaping.cc b/third_party/abseil_cpp/absl/strings/internal/escaping.cc deleted file mode 100644 index c5271286ad00..000000000000 --- a/third_party/abseil_cpp/absl/strings/internal/escaping.cc +++ /dev/null @@ -1,180 +0,0 @@ -// Copyright 2020 The Abseil Authors. -// -// Licensed 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 -// -// https://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 "absl/strings/internal/escaping.h" - -#include "absl/base/internal/endian.h" -#include "absl/base/internal/raw_logging.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace strings_internal { - -const char kBase64Chars[] = - "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; - -size_t CalculateBase64EscapedLenInternal(size_t input_len, bool do_padding) { - // Base64 encodes three bytes of input at a time. If the input is not - // divisible by three, we pad as appropriate. - // - // (from https://tools.ietf.org/html/rfc3548) - // Special processing is performed if fewer than 24 bits are available - // at the end of the data being encoded. A full encoding quantum is - // always completed at the end of a quantity. When fewer than 24 input - // bits are available in an input group, zero bits are added (on the - // right) to form an integral number of 6-bit groups. Padding at the - // end of the data is performed using the '=' character. Since all base - // 64 input is an integral number of octets, only the following cases - // can arise: - - // Base64 encodes each three bytes of input into four bytes of output. - size_t len = (input_len / 3) * 4; - - if (input_len % 3 == 0) { - // (from https://tools.ietf.org/html/rfc3548) - // (1) the final quantum of encoding input is an integral multiple of 24 - // bits; here, the final unit of encoded output will be an integral - // multiple of 4 characters with no "=" padding, - } else if (input_len % 3 == 1) { - // (from https://tools.ietf.org/html/rfc3548) - // (2) the final quantum of encoding input is exactly 8 bits; here, the - // final unit of encoded output will be two characters followed by two - // "=" padding characters, or - len += 2; - if (do_padding) { - len += 2; - } - } else { // (input_len % 3 == 2) - // (from https://tools.ietf.org/html/rfc3548) - // (3) the final quantum of encoding input is exactly 16 bits; here, the - // final unit of encoded output will be three characters followed by one - // "=" padding character. - len += 3; - if (do_padding) { - len += 1; - } - } - - assert(len >= input_len); // make sure we didn't overflow - return len; -} - -size_t Base64EscapeInternal(const unsigned char* src, size_t szsrc, char* dest, - size_t szdest, const char* base64, - bool do_padding) { - static const char kPad64 = '='; - - if (szsrc * 4 > szdest * 3) return 0; - - char* cur_dest = dest; - const unsigned char* cur_src = src; - - char* const limit_dest = dest + szdest; - const unsigned char* const limit_src = src + szsrc; - - // Three bytes of data encodes to four characters of cyphertext. - // So we can pump through three-byte chunks atomically. - if (szsrc >= 3) { // "limit_src - 3" is UB if szsrc < 3. - while (cur_src < limit_src - 3) { // While we have >= 32 bits. - uint32_t in = absl::big_endian::Load32(cur_src) >> 8; - - cur_dest[0] = base64[in >> 18]; - in &= 0x3FFFF; - cur_dest[1] = base64[in >> 12]; - in &= 0xFFF; - cur_dest[2] = base64[in >> 6]; - in &= 0x3F; - cur_dest[3] = base64[in]; - - cur_dest += 4; - cur_src += 3; - } - } - // To save time, we didn't update szdest or szsrc in the loop. So do it now. - szdest = limit_dest - cur_dest; - szsrc = limit_src - cur_src; - - /* now deal with the tail (<=3 bytes) */ - switch (szsrc) { - case 0: - // Nothing left; nothing more to do. - break; - case 1: { - // One byte left: this encodes to two characters, and (optionally) - // two pad characters to round out the four-character cypherblock. - if (szdest < 2) return 0; - uint32_t in = cur_src[0]; - cur_dest[0] = base64[in >> 2]; - in &= 0x3; - cur_dest[1] = base64[in << 4]; - cur_dest += 2; - szdest -= 2; - if (do_padding) { - if (szdest < 2) return 0; - cur_dest[0] = kPad64; - cur_dest[1] = kPad64; - cur_dest += 2; - szdest -= 2; - } - break; - } - case 2: { - // Two bytes left: this encodes to three characters, and (optionally) - // one pad character to round out the four-character cypherblock. - if (szdest < 3) return 0; - uint32_t in = absl::big_endian::Load16(cur_src); - cur_dest[0] = base64[in >> 10]; - in &= 0x3FF; - cur_dest[1] = base64[in >> 4]; - in &= 0x00F; - cur_dest[2] = base64[in << 2]; - cur_dest += 3; - szdest -= 3; - if (do_padding) { - if (szdest < 1) return 0; - cur_dest[0] = kPad64; - cur_dest += 1; - szdest -= 1; - } - break; - } - case 3: { - // Three bytes left: same as in the big loop above. We can't do this in - // the loop because the loop above always reads 4 bytes, and the fourth - // byte is past the end of the input. - if (szdest < 4) return 0; - uint32_t in = (cur_src[0] << 16) + absl::big_endian::Load16(cur_src + 1); - cur_dest[0] = base64[in >> 18]; - in &= 0x3FFFF; - cur_dest[1] = base64[in >> 12]; - in &= 0xFFF; - cur_dest[2] = base64[in >> 6]; - in &= 0x3F; - cur_dest[3] = base64[in]; - cur_dest += 4; - szdest -= 4; - break; - } - default: - // Should not be reached: blocks of 4 bytes are handled - // in the while loop before this switch statement. - ABSL_RAW_LOG(FATAL, "Logic problem? szsrc = %zu", szsrc); - break; - } - return (cur_dest - dest); -} - -} // namespace strings_internal -ABSL_NAMESPACE_END -} // namespace absl |