diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /media/gmp-clearkey/0.1/ClearKeyBase64.cpp | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/gmp-clearkey/0.1/ClearKeyBase64.cpp')
-rw-r--r-- | media/gmp-clearkey/0.1/ClearKeyBase64.cpp | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/media/gmp-clearkey/0.1/ClearKeyBase64.cpp b/media/gmp-clearkey/0.1/ClearKeyBase64.cpp new file mode 100644 index 0000000000..bb610afd1b --- /dev/null +++ b/media/gmp-clearkey/0.1/ClearKeyBase64.cpp @@ -0,0 +1,90 @@ +/* + * Copyright 2015, Mozilla Foundation and contributors + * + * 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 + * + * 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 "ClearKeyBase64.h" + +#include <algorithm> + +using std::string; +using std::vector; + +/** + * Take a base64-encoded string, convert (in-place) each character to its + * corresponding value in the [0x00, 0x3f] range, and truncate any padding. + */ +static bool Decode6Bit(string& aStr) { + for (size_t i = 0; i < aStr.length(); i++) { + if (aStr[i] >= 'A' && aStr[i] <= 'Z') { + aStr[i] -= 'A'; + } else if (aStr[i] >= 'a' && aStr[i] <= 'z') { + aStr[i] -= 'a' - 26; + } else if (aStr[i] >= '0' && aStr[i] <= '9') { + aStr[i] -= '0' - 52; + } else if (aStr[i] == '-' || aStr[i] == '+') { + aStr[i] = 62; + } else if (aStr[i] == '_' || aStr[i] == '/') { + aStr[i] = 63; + } else { + // Truncate '=' padding at the end of the aString. + if (aStr[i] != '=') { + aStr.erase(i, string::npos); + return false; + } + aStr[i] = '\0'; + aStr.resize(i); + break; + } + } + + return true; +} + +bool DecodeBase64(const string& aEncoded, vector<uint8_t>& aOutDecoded) { + if (aEncoded.empty()) { + aOutDecoded.clear(); + return true; + } + if (aEncoded.size() == 1) { + // Invalid Base64 encoding. + return false; + } + string encoded = aEncoded; + if (!Decode6Bit(encoded)) { + return false; + } + + // The number of bytes we haven't yet filled in the current byte, mod 8. + int shift = 0; + + aOutDecoded.resize((encoded.size() * 3) / 4); + vector<uint8_t>::iterator out = aOutDecoded.begin(); + for (size_t i = 0; i < encoded.length(); i++) { + if (!shift) { + *out = encoded[i] << 2; + } else { + *out |= encoded[i] >> (6 - shift); + out++; + if (out == aOutDecoded.end()) { + // Hit last 6bit octed in encoded, which is padding and can be ignored. + break; + } + *out = encoded[i] << (shift + 2); + } + shift = (shift + 2) % 8; + } + + return true; +} |