Source code

Revision control

Other Tools

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Unused.h"
#include "SinfParser.h"
#include "AtomType.h"
#include "Box.h"
#include "ByteStream.h"
namespace mozilla {
Sinf::Sinf(Box& aBox) : mDefaultIVSize(0), mDefaultEncryptionType() {
SinfParser parser(aBox);
if (parser.GetSinf().IsValid()) {
*this = parser.GetSinf();
}
}
SinfParser::SinfParser(Box& aBox) {
for (Box box = aBox.FirstChild(); box.IsAvailable(); box = box.Next()) {
if (box.IsType("schm")) {
mozilla::Unused << ParseSchm(box);
} else if (box.IsType("schi")) {
mozilla::Unused << ParseSchi(box);
}
}
}
Result<Ok, nsresult> SinfParser::ParseSchm(Box& aBox) {
BoxReader reader(aBox);
if (reader->Remaining() < 8) {
return Err(NS_ERROR_FAILURE);
}
MOZ_TRY(reader->ReadU32()); // flags -- ignore
MOZ_TRY_VAR(mSinf.mDefaultEncryptionType, reader->ReadU32());
return Ok();
}
Result<Ok, nsresult> SinfParser::ParseSchi(Box& aBox) {
for (Box box = aBox.FirstChild(); box.IsAvailable(); box = box.Next()) {
if (box.IsType("tenc") && ParseTenc(box).isErr()) {
return Err(NS_ERROR_FAILURE);
}
}
return Ok();
}
Result<Ok, nsresult> SinfParser::ParseTenc(Box& aBox) {
BoxReader reader(aBox);
if (reader->Remaining() < 24) {
return Err(NS_ERROR_FAILURE);
}
uint32_t flags;
MOZ_TRY_VAR(flags, reader->ReadU32());
uint8_t version = flags >> 24;
// Skip reserved byte
MOZ_TRY(reader->ReadU8());
if (version >= 1) {
uint8_t pattern;
MOZ_TRY_VAR(pattern, reader->ReadU8());
mSinf.mDefaultCryptByteBlock = pattern >> 4;
mSinf.mDefaultSkipByteBlock = pattern & 0x0f;
} else {
// Reserved if version is less than 1
MOZ_TRY(reader->ReadU8());
mSinf.mDefaultCryptByteBlock = 0;
mSinf.mDefaultSkipByteBlock = 0;
}
uint8_t isEncrypted;
MOZ_TRY_VAR(isEncrypted, reader->ReadU8());
MOZ_TRY_VAR(mSinf.mDefaultIVSize, reader->ReadU8());
memcpy(mSinf.mDefaultKeyID, reader->Read(16), 16);
if (isEncrypted && mSinf.mDefaultIVSize == 0) {
uint8_t defaultConstantIVSize;
MOZ_TRY_VAR(defaultConstantIVSize, reader->ReadU8());
if (!mSinf.mDefaultConstantIV.SetLength(defaultConstantIVSize,
mozilla::fallible)) {
return Err(NS_ERROR_FAILURE);
}
for (uint8_t i = 0; i < defaultConstantIVSize; i++) {
MOZ_TRY_VAR(mSinf.mDefaultConstantIV.ElementAt(i), reader->ReadU8());
}
}
return Ok();
}
} // namespace mozilla