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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#include "SRICheck.h"
#include "mozilla/Base64.h"
#include "mozilla/LoadTainting.h"
#include "mozilla/Logging.h"
#include "mozilla/Preferences.h"
#include "mozilla/dom/SRILogHelper.h"
#include "mozilla/dom/SRIMetadata.h"
#include "nsComponentManagerUtils.h"
#include "nsContentUtils.h"
#include "nsIChannel.h"
#include "nsIConsoleReportCollector.h"
#include "nsIScriptError.h"
#include "nsIURI.h"
#include "nsNetUtil.h"
#include "nsWhitespaceTokenizer.h"
#define SRIVERBOSE(args) \
MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Verbose, args)
#define SRILOG(args) \
MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug, args)
#define SRIERROR(args) \
MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Error, args)
namespace mozilla::dom {
/**
* Returns whether or not the sub-resource about to be loaded is eligible
* for integrity checks. If it's not, the checks will be skipped and the
* sub-resource will be loaded.
*/
static nsresult IsEligible(nsIChannel* aChannel,
mozilla::LoadTainting aTainting,
const nsACString& aSourceFileURI,
nsIConsoleReportCollector* aReporter) {
NS_ENSURE_ARG_POINTER(aReporter);
if (!aChannel) {
SRILOG(("SRICheck::IsEligible, null channel"));
return NS_ERROR_SRI_NOT_ELIGIBLE;
}
// Was the sub-resource loaded via CORS?
if (aTainting == LoadTainting::CORS) {
SRILOG(("SRICheck::IsEligible, CORS mode"));
return NS_OK;
}
nsCOMPtr<nsIURI> finalURI;
nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(finalURI));
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIURI> originalURI;
rv = aChannel->GetOriginalURI(getter_AddRefs(originalURI));
NS_ENSURE_SUCCESS(rv, rv);
nsAutoCString requestSpec;
rv = originalURI->GetSpec(requestSpec);
NS_ENSURE_SUCCESS(rv, rv);
if (MOZ_LOG_TEST(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug)) {
SRILOG(("SRICheck::IsEligible, requestURI=%s; finalURI=%s",
requestSpec.get(),
finalURI ? finalURI->GetSpecOrDefault().get() : ""));
}
// Is the sub-resource same-origin?
if (aTainting == LoadTainting::Basic) {
SRILOG(("SRICheck::IsEligible, same-origin"));
return NS_OK;
}
SRILOG(("SRICheck::IsEligible, NOT same-origin"));
NS_ConvertUTF8toUTF16 requestSpecUTF16(requestSpec);
nsTArray<nsString> params;
params.AppendElement(requestSpecUTF16);
aReporter->AddConsoleReport(
nsIScriptError::errorFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"IneligibleResource"_ns, const_cast<const nsTArray<nsString>&>(params));
return NS_ERROR_SRI_NOT_ELIGIBLE;
}
/* static */
nsresult SRICheck::IntegrityMetadata(const nsAString& aMetadataList,
const nsACString& aSourceFileURI,
nsIConsoleReportCollector* aReporter,
SRIMetadata* outMetadata) {
NS_ENSURE_ARG_POINTER(outMetadata);
NS_ENSURE_ARG_POINTER(aReporter);
MOZ_ASSERT(outMetadata->IsEmpty()); // caller must pass empty metadata
NS_ConvertUTF16toUTF8 metadataList(aMetadataList);
SRILOG(("SRICheck::IntegrityMetadata, metadataList=%s", metadataList.get()));
// the integrity attribute is a list of whitespace-separated hashes
// and options so we need to look at them one by one and pick the
// strongest (valid) one
nsCWhitespaceTokenizer tokenizer(metadataList);
nsAutoCString token;
while (tokenizer.hasMoreTokens()) {
token = tokenizer.nextToken();
SRIMetadata metadata(token);
if (metadata.IsMalformed()) {
NS_ConvertUTF8toUTF16 tokenUTF16(token);
nsTArray<nsString> params;
params.AppendElement(tokenUTF16);
aReporter->AddConsoleReport(
nsIScriptError::warningFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"MalformedIntegrityHash"_ns,
const_cast<const nsTArray<nsString>&>(params));
} else if (!metadata.IsAlgorithmSupported()) {
nsAutoCString alg;
metadata.GetAlgorithm(&alg);
NS_ConvertUTF8toUTF16 algUTF16(alg);
nsTArray<nsString> params;
params.AppendElement(algUTF16);
aReporter->AddConsoleReport(
nsIScriptError::warningFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"UnsupportedHashAlg"_ns,
const_cast<const nsTArray<nsString>&>(params));
}
nsAutoCString alg1, alg2;
if (MOZ_LOG_TEST(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug)) {
outMetadata->GetAlgorithm(&alg1);
metadata.GetAlgorithm(&alg2);
}
if (*outMetadata == metadata) {
SRILOG(("SRICheck::IntegrityMetadata, alg '%s' is the same as '%s'",
alg1.get(), alg2.get()));
*outMetadata += metadata; // add new hash to strongest metadata
} else if (*outMetadata < metadata) {
SRILOG(("SRICheck::IntegrityMetadata, alg '%s' is weaker than '%s'",
alg1.get(), alg2.get()));
*outMetadata = metadata; // replace strongest metadata with current
}
}
outMetadata->mIntegrityString = aMetadataList;
if (MOZ_LOG_TEST(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug)) {
if (outMetadata->IsValid()) {
nsAutoCString alg;
outMetadata->GetAlgorithm(&alg);
SRILOG(("SRICheck::IntegrityMetadata, using a '%s' hash", alg.get()));
} else if (outMetadata->IsEmpty()) {
SRILOG(("SRICheck::IntegrityMetadata, no metadata"));
} else {
SRILOG(("SRICheck::IntegrityMetadata, no valid metadata found"));
}
}
return NS_OK;
}
//////////////////////////////////////////////////////////////
//
//////////////////////////////////////////////////////////////
SRICheckDataVerifier::SRICheckDataVerifier(const SRIMetadata& aMetadata,
const nsACString& aSourceFileURI,
nsIConsoleReportCollector* aReporter)
: mCryptoHash(nullptr),
mBytesHashed(0),
mHashLength(0),
mHashType('\0'),
mInvalidMetadata(false),
mComplete(false) {
MOZ_ASSERT(!aMetadata.IsEmpty()); // should be checked by caller
MOZ_ASSERT(aReporter);
if (!aMetadata.IsValid()) {
nsTArray<nsString> params;
aReporter->AddConsoleReport(
nsIScriptError::warningFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"NoValidMetadata"_ns, const_cast<const nsTArray<nsString>&>(params));
mInvalidMetadata = true;
return; // ignore invalid metadata for forward-compatibility
}
aMetadata.GetHashType(&mHashType, &mHashLength);
}
nsresult SRICheckDataVerifier::EnsureCryptoHash() {
MOZ_ASSERT(!mInvalidMetadata);
if (mCryptoHash) {
return NS_OK;
}
nsCOMPtr<nsICryptoHash> cryptoHash;
nsresult rv = NS_NewCryptoHash(mHashType, getter_AddRefs(cryptoHash));
NS_ENSURE_SUCCESS(rv, rv);
mCryptoHash = cryptoHash;
return NS_OK;
}
nsresult SRICheckDataVerifier::Update(uint32_t aStringLen,
const uint8_t* aString) {
NS_ENSURE_ARG_POINTER(aString);
if (mInvalidMetadata) {
return NS_OK; // ignoring any data updates, see mInvalidMetadata usage
}
nsresult rv;
rv = EnsureCryptoHash();
NS_ENSURE_SUCCESS(rv, rv);
mBytesHashed += aStringLen;
return mCryptoHash->Update(aString, aStringLen);
}
nsresult SRICheckDataVerifier::Finish() {
if (mInvalidMetadata || mComplete) {
return NS_OK; // already finished or invalid metadata
}
nsresult rv;
rv = EnsureCryptoHash(); // we need computed hash even for 0-length data
NS_ENSURE_SUCCESS(rv, rv);
rv = mCryptoHash->Finish(false, mComputedHash);
mCryptoHash = nullptr;
mComplete = true;
return rv;
}
nsresult SRICheckDataVerifier::VerifyHash(
const SRIMetadata& aMetadata, uint32_t aHashIndex,
const nsACString& aSourceFileURI, nsIConsoleReportCollector* aReporter) {
NS_ENSURE_ARG_POINTER(aReporter);
nsAutoCString base64Hash;
aMetadata.GetHash(aHashIndex, &base64Hash);
SRILOG(("SRICheckDataVerifier::VerifyHash, hash[%u]=%s", aHashIndex,
base64Hash.get()));
nsAutoCString binaryHash;
// We're decoding the supplied hash twice. Trying base64 first.
nsresult rv = Base64Decode(base64Hash, binaryHash);
if (NS_FAILED(rv)) {
SRILOG(
("SRICheckDataVerifier::VerifyHash, base64 decoding failed. Trying "
"base64url next."));
FallibleTArray<uint8_t> decoded;
rv = Base64URLDecode(base64Hash, Base64URLDecodePaddingPolicy::Ignore,
decoded);
if (NS_FAILED(rv)) {
SRILOG(
("SRICheckDataVerifier::VerifyHash, base64url decoding failed too. "
"Bailing out."));
// if neither succeeded, we can bail out and warn
nsTArray<nsString> params;
aReporter->AddConsoleReport(
nsIScriptError::errorFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"InvalidIntegrityBase64"_ns,
const_cast<const nsTArray<nsString>&>(params));
return NS_ERROR_SRI_CORRUPT;
}
binaryHash.Assign(reinterpret_cast<const char*>(decoded.Elements()),
decoded.Length());
SRILOG(
("SRICheckDataVerifier::VerifyHash, decoded supplied base64url hash "
"successfully."));
} else {
SRILOG(
("SRICheckDataVerifier::VerifyHash, decoded supplied base64 hash "
"successfully."));
}
uint32_t hashLength;
int8_t hashType;
aMetadata.GetHashType(&hashType, &hashLength);
if (binaryHash.Length() != hashLength) {
SRILOG(
("SRICheckDataVerifier::VerifyHash, supplied base64(url) hash was "
"incorrect length after decoding."));
nsTArray<nsString> params;
aReporter->AddConsoleReport(
nsIScriptError::errorFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"InvalidIntegrityLength"_ns,
const_cast<const nsTArray<nsString>&>(params));
return NS_ERROR_SRI_CORRUPT;
}
// the decoded supplied hash should match our computed binary hash.
if (!binaryHash.Equals(mComputedHash)) {
SRILOG(("SRICheckDataVerifier::VerifyHash, hash[%u] did not match",
aHashIndex));
return NS_ERROR_SRI_CORRUPT;
}
SRILOG(("SRICheckDataVerifier::VerifyHash, hash[%u] verified successfully",
aHashIndex));
return NS_OK;
}
nsresult SRICheckDataVerifier::Verify(const SRIMetadata& aMetadata,
nsIChannel* aChannel,
const nsACString& aSourceFileURI,
nsIConsoleReportCollector* aReporter) {
NS_ENSURE_ARG_POINTER(aReporter);
if (MOZ_LOG_TEST(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug)) {
nsAutoCString requestURL;
nsCOMPtr<nsIRequest> request = aChannel;
request->GetName(requestURL);
SRILOG(("SRICheckDataVerifier::Verify, url=%s (length=%zu)",
requestURL.get(), mBytesHashed));
}
nsresult rv = Finish();
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
LoadTainting tainting = loadInfo->GetTainting();
if (NS_FAILED(IsEligible(aChannel, tainting, aSourceFileURI, aReporter))) {
return NS_ERROR_SRI_NOT_ELIGIBLE;
}
if (mInvalidMetadata) {
return NS_OK; // ignore invalid metadata for forward-compatibility
}
for (uint32_t i = 0; i < aMetadata.HashCount(); i++) {
if (NS_SUCCEEDED(VerifyHash(aMetadata, i, aSourceFileURI, aReporter))) {
return NS_OK; // stop at the first valid hash
}
}
nsAutoCString alg;
aMetadata.GetAlgorithm(&alg);
NS_ConvertUTF8toUTF16 algUTF16(alg);
nsAutoCString encodedHash;
rv = Base64Encode(mComputedHash, encodedHash);
NS_ENSURE_SUCCESS(rv, rv);
NS_ConvertUTF8toUTF16 encodedHashUTF16(encodedHash);
nsTArray<nsString> params;
params.AppendElement(algUTF16);
params.AppendElement(encodedHashUTF16);
aReporter->AddConsoleReport(
nsIScriptError::errorFlag, "Sub-resource Integrity"_ns,
nsContentUtils::eSECURITY_PROPERTIES, aSourceFileURI, 0, 0,
"IntegrityMismatch2"_ns, const_cast<const nsTArray<nsString>&>(params));
return NS_ERROR_SRI_CORRUPT;
}
uint32_t SRICheckDataVerifier::DataSummaryLength() {
MOZ_ASSERT(!mInvalidMetadata);
return sizeof(mHashType) + sizeof(mHashLength) + mHashLength;
}
uint32_t SRICheckDataVerifier::EmptyDataSummaryLength() {
return sizeof(int8_t) + sizeof(uint32_t);
}
nsresult SRICheckDataVerifier::DataSummaryLength(uint32_t aDataLen,
const uint8_t* aData,
uint32_t* length) {
*length = 0;
NS_ENSURE_ARG_POINTER(aData);
// we expect to always encode an SRI, even if it is empty or incomplete
if (aDataLen < EmptyDataSummaryLength()) {
SRILOG(
("SRICheckDataVerifier::DataSummaryLength, encoded length[%u] is too "
"small",
aDataLen));
return NS_ERROR_SRI_IMPORT;
}
// decode the content of the buffer
size_t offset = sizeof(mHashType);
decltype(mHashLength) len = 0;
memcpy(&len, &aData[offset], sizeof(mHashLength));
offset += sizeof(mHashLength);
SRIVERBOSE(
("SRICheckDataVerifier::DataSummaryLength, header {%x, %x, %x, %x, %x, "
"...}",
aData[0], aData[1], aData[2], aData[3], aData[4]));
if (offset + len > aDataLen) {
SRILOG(
("SRICheckDataVerifier::DataSummaryLength, encoded length[%u] overflow "
"the buffer size",
aDataLen));
SRIVERBOSE(("SRICheckDataVerifier::DataSummaryLength, offset[%u], len[%u]",
uint32_t(offset), uint32_t(len)));
return NS_ERROR_SRI_IMPORT;
}
*length = uint32_t(offset + len);
return NS_OK;
}
nsresult SRICheckDataVerifier::ImportDataSummary(uint32_t aDataLen,
const uint8_t* aData) {
MOZ_ASSERT(!mInvalidMetadata); // mHashType and mHashLength should be valid
MOZ_ASSERT(!mCryptoHash); // EnsureCryptoHash should not have been called
NS_ENSURE_ARG_POINTER(aData);
if (mInvalidMetadata) {
return NS_OK; // ignoring any data updates, see mInvalidMetadata usage
}
// we expect to always encode an SRI, even if it is empty or incomplete
if (aDataLen < DataSummaryLength()) {
SRILOG(
("SRICheckDataVerifier::ImportDataSummary, encoded length[%u] is too "
"small",
aDataLen));
return NS_ERROR_SRI_IMPORT;
}
SRIVERBOSE(
("SRICheckDataVerifier::ImportDataSummary, header {%x, %x, %x, %x, %x, "
"...}",
aData[0], aData[1], aData[2], aData[3], aData[4]));
// decode the content of the buffer
size_t offset = 0;
decltype(mHashType) hashType;
memcpy(&hashType, &aData[offset], sizeof(mHashType));
if (hashType != mHashType) {
SRILOG(
("SRICheckDataVerifier::ImportDataSummary, hash type[%d] does not "
"match[%d]",
hashType, mHashType));
return NS_ERROR_SRI_UNEXPECTED_HASH_TYPE;
}
offset += sizeof(mHashType);
decltype(mHashLength) hashLength;
memcpy(&hashLength, &aData[offset], sizeof(mHashLength));
if (hashLength != mHashLength) {
SRILOG(
("SRICheckDataVerifier::ImportDataSummary, hash length[%d] does not "
"match[%d]",
hashLength, mHashLength));
return NS_ERROR_SRI_UNEXPECTED_HASH_TYPE;
}
offset += sizeof(mHashLength);
// copy the hash to mComputedHash, as-if we had finished streaming the bytes
mComputedHash.Assign(reinterpret_cast<const char*>(&aData[offset]),
mHashLength);
mCryptoHash = nullptr;
mComplete = true;
return NS_OK;
}
nsresult SRICheckDataVerifier::ExportDataSummary(uint32_t aDataLen,
uint8_t* aData) {
MOZ_ASSERT(!mInvalidMetadata); // mHashType and mHashLength should be valid
MOZ_ASSERT(mComplete); // finished streaming
NS_ENSURE_ARG_POINTER(aData);
NS_ENSURE_TRUE(aDataLen >= DataSummaryLength(), NS_ERROR_INVALID_ARG);
// serialize the hash in the buffer
size_t offset = 0;
memcpy(&aData[offset], &mHashType, sizeof(mHashType));
offset += sizeof(mHashType);
memcpy(&aData[offset], &mHashLength, sizeof(mHashLength));
offset += sizeof(mHashLength);
SRIVERBOSE(
("SRICheckDataVerifier::ExportDataSummary, header {%x, %x, %x, %x, %x, "
"...}",
aData[0], aData[1], aData[2], aData[3], aData[4]));
// copy the hash to mComputedHash, as-if we had finished streaming the bytes
nsCharTraits<char>::copy(reinterpret_cast<char*>(&aData[offset]),
mComputedHash.get(), mHashLength);
return NS_OK;
}
nsresult SRICheckDataVerifier::ExportEmptyDataSummary(uint32_t aDataLen,
uint8_t* aData) {
NS_ENSURE_ARG_POINTER(aData);
NS_ENSURE_TRUE(aDataLen >= EmptyDataSummaryLength(), NS_ERROR_INVALID_ARG);
// serialize an unknown hash in the buffer, to be able to skip it later
size_t offset = 0;
memset(&aData[offset], 0, sizeof(mHashType));
offset += sizeof(mHashType);
memset(&aData[offset], 0, sizeof(mHashLength));
SRIVERBOSE(
("SRICheckDataVerifier::ExportEmptyDataSummary, header {%x, %x, %x, %x, "
"%x, ...}",
aData[0], aData[1], aData[2], aData[3], aData[4]));
return NS_OK;
}
} // namespace mozilla::dom