nagai/fune
3
0
Fork 0
forked from mirrors/gecko-dev
Code Pull requests Activity

Bug 1792041 - Add a value for DEL to kBase64URLDecodeTable and have static asserts for lookup tables' length. r=xpcom-reviewers,nika

Browse source 
Differential Revision: https://phabricator.services.mozilla.com/D158239
This commit is contained in:
Jens Stutte 2022-09-29 21:56:28 +00:00
parent 5f1ab2cd4b
commit ec8b482d3b
1 changed files with 13 additions and 11 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

24
xpcom/io/Base64.cpp
View file

@ -276,26 +276,23 @@ static const uint8_t kBase64DecodeTable[] = {
/* 112 */ 41, 42, 43, 44, 45, 46, 47, 48,
/* 120 */ 49, 50, 51, 255, 255, 255, 255, 255,
};
static_assert(mozilla::ArrayLength(kBase64DecodeTable) == 0x80);
// clang-format on
template <typename T>
[[nodiscard]] bool Base64CharToValue(T aChar, uint8_t* aValue) {
static const size_t mask = 0x7f;
static_assert(
(mask + 1) == sizeof(kBase64DecodeTable) / sizeof(kBase64DecodeTable[0]),
"wrong mask");
size_t index = static_cast<uint8_t>(aChar);
if (index & ~mask) {
if (index >= mozilla::ArrayLength(kBase64DecodeTable)) {
*aValue = 255;
return false;
}
*aValue = kBase64DecodeTable[index & mask];
*aValue = kBase64DecodeTable[index];
return *aValue != 255;
}
static const char kBase64URLAlphabet[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
static_assert(mozilla::ArrayLength(kBase64URLAlphabet) == 0x41);
// Maps an encoded character to a value in the Base64 URL alphabet, per
// RFC 4648, Table 2. Invalid input characters map to UINT8_MAX.
@ -318,14 +315,19 @@ static const uint8_t kBase64URLDecodeTable[] = {
255,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
42, 43, 44, 45, 46, 47, 48, 49, 50, 51, /* a - z */
255, 255, 255, 255,
255, 255, 255, 255, 255,
};
static_assert(mozilla::ArrayLength(kBase64URLDecodeTable) == 0x80);
// clang-format on
bool Base64URLCharToValue(char aChar, uint8_t* aValue) {
uint8_t index = static_cast<uint8_t>(aChar);
*aValue = kBase64URLDecodeTable[index & 0x7f];
return (*aValue != 255) && !(index & ~0x7f);
if (index >= mozilla::ArrayLength(kBase64URLDecodeTable)) {
*aValue = 255;
return false;
}
*aValue = kBase64URLDecodeTable[index];
return *aValue != 255;
}
} // namespace