ctr_encryption_layer: Fix bug when transcoding small data

Fixes a bug where data lengths of less than size 0x10 will fail or have misleading return values.
This commit is contained in:
Zach Hilman 2018-08-16 16:58:49 -04:00
parent a9dc5a3c10
commit 6dd369ab88

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@ -20,10 +20,8 @@ size_t CTREncryptionLayer::Read(u8* data, size_t length, size_t offset) const {
if (sector_offset == 0) { if (sector_offset == 0) {
UpdateIV(base_offset + offset); UpdateIV(base_offset + offset);
std::vector<u8> raw = base->ReadBytes(length, offset); std::vector<u8> raw = base->ReadBytes(length, offset);
if (raw.size() != length) cipher.Transcode(raw.data(), raw.size(), data, Op::Decrypt);
return Read(data, raw.size(), offset); return raw.size();
cipher.Transcode(raw.data(), length, data, Op::Decrypt);
return length;
} }
// offset does not fall on block boundary (0x10) // offset does not fall on block boundary (0x10)
@ -34,7 +32,7 @@ size_t CTREncryptionLayer::Read(u8* data, size_t length, size_t offset) const {
if (length + sector_offset < 0x10) { if (length + sector_offset < 0x10) {
std::memcpy(data, block.data() + sector_offset, std::min<u64>(length, read)); std::memcpy(data, block.data() + sector_offset, std::min<u64>(length, read));
return read; return std::min<u64>(length, read);
} }
std::memcpy(data, block.data() + sector_offset, read); std::memcpy(data, block.data() + sector_offset, read);
return read + Read(data + read, length - read, offset + read); return read + Read(data + read, length - read, offset + read);