bool
RTCCertificate::ReadCertificate(JSStructuredCloneReader* aReader,
const nsNSSShutDownPreventionLock& /*proof*/)
{
CryptoBuffer cert;
if (!ReadBuffer(aReader, cert) || cert.Length() == 0) {
return false;
}
SECItem der = { siBuffer, cert.Elements(),
static_cast<unsigned int>(cert.Length()) };
mCertificate.reset(CERT_NewTempCertificate(CERT_GetDefaultCertDB(),
&der, nullptr, true, true));
return !!mCertificate;
}
static nsresult
U2FAssembleAuthenticatorData(/* out */ CryptoBuffer& aAuthenticatorData,
const CryptoBuffer& aRpIdHash,
const CryptoBuffer& aSignatureData)
{
// The AuthenticatorData for U2F devices is the concatenation of the
// RP ID with the output of the U2F Sign operation.
if (aRpIdHash.Length() != 32) {
return NS_ERROR_INVALID_ARG;
}
if (!aAuthenticatorData.AppendElements(aRpIdHash, mozilla::fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
if (!aAuthenticatorData.AppendElements(aSignatureData, mozilla::fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
return NS_OK;
}
NS_IMETHODIMP
U2FSignTask::Run()
{
nsNSSShutDownPreventionLock locker;
if (isAlreadyShutDown()) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Search the requests for one a token can fulfill
for (size_t i = 0; i < mRegisteredKeys.Length(); i += 1) {
RegisteredKey request(mRegisteredKeys[i]);
// Check for required attributes
if (!(request.mVersion.WasPassed() &&
request.mKeyHandle.WasPassed())) {
continue;
}
// Do not permit an individual RegisteredKey to assert a different AppID
if (request.mAppId.WasPassed() && mAppId != request.mAppId.Value()) {
continue;
}
// Assemble a clientData object
CryptoBuffer clientData;
nsresult rv = AssembleClientData(mOrigin, kGetAssertion, mChallenge,
clientData);
if (NS_WARN_IF(NS_FAILED(rv))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Hash the AppID and the ClientData into the AppParam and ChallengeParam
SECStatus srv;
nsCString cAppId = NS_ConvertUTF16toUTF8(mAppId);
CryptoBuffer appParam;
CryptoBuffer challengeParam;
if (!appParam.SetLength(SHA256_LENGTH, fallible) ||
!challengeParam.SetLength(SHA256_LENGTH, fallible)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
srv = PK11_HashBuf(SEC_OID_SHA256, appParam.Elements(),
reinterpret_cast<const uint8_t*>(cAppId.BeginReading()),
cAppId.Length());
if (srv != SECSuccess) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
srv = PK11_HashBuf(SEC_OID_SHA256, challengeParam.Elements(),
clientData.Elements(), clientData.Length());
if (srv != SECSuccess) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Decode the key handle
CryptoBuffer keyHandle;
rv = keyHandle.FromJwkBase64(request.mKeyHandle.Value());
if (NS_WARN_IF(NS_FAILED(rv))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Get the signature from the token
CryptoBuffer signatureData;
bool signSuccess = false;
// We ignore mTransports, as it is intended to be used for sorting the
// available devices by preference, but is not an exclusion factor.
for (size_t a = 0; a < mAuthenticators.Length() && !signSuccess; ++a) {
Authenticator token(mAuthenticators[a]);
bool isCompatible = false;
bool isRegistered = false;
rv = token->IsCompatibleVersion(request.mVersion.Value(), &isCompatible);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (!isCompatible) {
continue;
}
rv = token->IsRegistered(keyHandle.Elements(), keyHandle.Length(),
&isRegistered);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (isCompatible && isRegistered) {
uint8_t* buffer;
uint32_t bufferlen;
nsresult rv = token->Sign(appParam.Elements(), appParam.Length(),
challengeParam.Elements(), challengeParam.Length(),
keyHandle.Elements(), keyHandle.Length(),
&buffer, &bufferlen);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
MOZ_ASSERT(buffer);
signatureData.Assign(buffer, bufferlen);
free(buffer);
signSuccess = true;
}
}
if (!signSuccess) {
// Try another request
continue;
}
// Assemble a response object to return
nsString clientDataBase64, signatureDataBase64;
nsresult rvClientData =
clientData.ToJwkBase64(clientDataBase64);
nsresult rvSignatureData =
signatureData.ToJwkBase64(signatureDataBase64);
if (NS_WARN_IF(NS_FAILED(rvClientData)) ||
NS_WARN_IF(NS_FAILED(rvSignatureData))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
SignResponse response;
response.mKeyHandle.Construct(request.mKeyHandle.Value());
response.mClientData.Construct(clientDataBase64);
response.mSignatureData.Construct(signatureDataBase64);
response.mErrorCode.Construct(static_cast<uint32_t>(ErrorCode::OK));
ErrorResult result;
mCallback->Call(response, result);
NS_WARN_IF(result.Failed());
// Useful exceptions already got reported.
result.SuppressException();
return NS_OK;
}
// Nothing could satisfy
ReturnError(ErrorCode::DEVICE_INELIGIBLE);
return NS_ERROR_FAILURE;
}
// NOTE: This method represents a theoretical way to use a U2F-compliant token
// to produce the result of the WebAuthn GetAssertion method. The exact mapping
// of U2F data fields to WebAuthn data fields is still a matter of ongoing
// discussion, and this should not be taken as anything but a point-in- time
// possibility.
void
WebAuthentication::U2FAuthGetAssertion(const RefPtr<AssertionRequest>& aRequest,
const Authenticator& aToken, CryptoBuffer& aRpIdHash,
const nsACString& aClientData, CryptoBuffer& aClientDataHash,
nsTArray<CryptoBuffer>& aAllowList,
const WebAuthnExtensions& aExtensions)
{
MOZ_LOG(gWebauthLog, LogLevel::Debug, ("U2FAuthGetAssertion"));
// 4.1.2.7.e Add an entry to issuedRequests, corresponding to this request.
aRequest->AddActiveToken(__func__);
// 4.1.2.8 While issuedRequests is not empty, perform the following actions
// depending upon the adjustedTimeout timer and responses from the
// authenticators:
// 4.1.2.8.a If the timer for adjustedTimeout expires, then for each entry
// in issuedRequests invoke the authenticatorCancel operation on that
// authenticator and remove its entry from the list.
for (CryptoBuffer& allowedCredential : aAllowList) {
bool isRegistered = false;
nsresult rv = aToken->IsRegistered(allowedCredential.Elements(),
allowedCredential.Length(),
&isRegistered);
// 4.1.2.8.b If any authenticator returns a status indicating that the user
// cancelled the operation, delete that authenticator’s entry from
// issuedRequests. For each remaining entry in issuedRequests invoke the
// authenticatorCancel operation on that authenticator, and remove its entry
// from the list.
// 4.1.2.8.c If any authenticator returns an error status, delete the
// corresponding entry from issuedRequests.
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
if (!isRegistered) {
continue;
}
// Sign
uint8_t* buffer;
uint32_t bufferlen;
rv = aToken->Sign(aRpIdHash.Elements(), aRpIdHash.Length(),
aClientDataHash.Elements(), aClientDataHash.Length(),
allowedCredential.Elements(), allowedCredential.Length(),
&buffer, &bufferlen);
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
MOZ_ASSERT(buffer);
CryptoBuffer signatureData;
if (NS_WARN_IF(!signatureData.Assign(buffer, bufferlen))) {
free(buffer);
aRequest->SetFailure(NS_ERROR_OUT_OF_MEMORY);
return;
}
free(buffer);
// 4.1.2.8.d If any authenticator returns success:
// 4.1.2.8.d.1 Remove this authenticator’s entry from issuedRequests.
// 4.1.2.8.d.2 Create a new WebAuthnAssertion object named value and
// populate its fields with the values returned from the authenticator as
// well as the clientDataJSON computed earlier.
CryptoBuffer clientDataBuf;
if (!clientDataBuf.Assign(aClientData)) {
aRequest->SetFailure(NS_ERROR_OUT_OF_MEMORY);
return;
}
CryptoBuffer authenticatorDataBuf;
rv = U2FAssembleAuthenticatorData(authenticatorDataBuf, aRpIdHash,
signatureData);
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
RefPtr<ScopedCredential> credential = new ScopedCredential(this);
credential->SetType(ScopedCredentialType::ScopedCred);
credential->SetId(allowedCredential);
AssertionPtr assertion = new WebAuthnAssertion(this);
assertion->SetCredential(credential);
assertion->SetClientData(clientDataBuf);
assertion->SetAuthenticatorData(authenticatorDataBuf);
assertion->SetSignature(signatureData);
// 4.1.2.8.d.3 For each remaining entry in issuedRequests invoke the
// authenticatorCancel operation on that authenticator and remove its entry
// from the list.
// 4.1.2.8.d.4 Resolve promise with value and terminate this algorithm.
aRequest->SetSuccess(assertion);
return;
}
// 4.1.2.9 Reject promise with a DOMException whose name is "NotAllowedError",
// and terminate this algorithm.
aRequest->SetFailure(NS_ERROR_DOM_NOT_ALLOWED_ERR);
}
// NOTE: This method represents a theoretical way to use a U2F-compliant token
// to produce the result of the WebAuthn MakeCredential method. The exact
// mapping of U2F data fields to WebAuthn data fields is still a matter of
// ongoing discussion, and this should not be taken as anything but a point-in-
// time possibility.
void
WebAuthentication::U2FAuthMakeCredential(
const RefPtr<CredentialRequest>& aRequest,
const Authenticator& aToken, CryptoBuffer& aRpIdHash,
const nsACString& aClientData, CryptoBuffer& aClientDataHash,
const Account& aAccount,
const nsTArray<ScopedCredentialParameters>& aNormalizedParams,
const Optional<Sequence<ScopedCredentialDescriptor>>& aExcludeList,
const WebAuthnExtensions& aExtensions)
{
MOZ_LOG(gWebauthLog, LogLevel::Debug, ("U2FAuthMakeCredential"));
aRequest->AddActiveToken(__func__);
// 5.1.1 When this operation is invoked, the authenticator must perform the
// following procedure:
// 5.1.1.a Check if all the supplied parameters are syntactically well-
// formed and of the correct length. If not, return an error code equivalent
// to UnknownError and terminate the operation.
if ((aRpIdHash.Length() != SHA256_LENGTH) ||
(aClientDataHash.Length() != SHA256_LENGTH)) {
aRequest->SetFailure(NS_ERROR_DOM_UNKNOWN_ERR);
return;
}
// 5.1.1.b Check if at least one of the specified combinations of
// ScopedCredentialType and cryptographic parameters is supported. If not,
// return an error code equivalent to NotSupportedError and terminate the
// operation.
bool isValidCombination = false;
for (size_t a = 0; a < aNormalizedParams.Length(); ++a) {
if (aNormalizedParams[a].mType == ScopedCredentialType::ScopedCred &&
aNormalizedParams[a].mAlgorithm.IsString() &&
aNormalizedParams[a].mAlgorithm.GetAsString().EqualsLiteral(
WEBCRYPTO_NAMED_CURVE_P256)) {
isValidCombination = true;
break;
}
}
if (!isValidCombination) {
aRequest->SetFailure(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
return;
}
// 5.1.1.c Check if a credential matching any of the supplied
// ScopedCredential identifiers is present on this authenticator. If so,
// return an error code equivalent to NotAllowedError and terminate the
// operation.
if (aExcludeList.WasPassed()) {
const Sequence<ScopedCredentialDescriptor>& list = aExcludeList.Value();
for (const ScopedCredentialDescriptor& scd : list) {
bool isRegistered = false;
uint8_t *data;
uint32_t len;
// data is owned by the Descriptor, do don't free it here.
if (NS_FAILED(ScopedCredentialGetData(scd, &data, &len))) {
aRequest->SetFailure(NS_ERROR_DOM_UNKNOWN_ERR);
return;
}
nsresult rv = aToken->IsRegistered(data, len, &isRegistered);
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
if (isRegistered) {
aRequest->SetFailure(NS_ERROR_DOM_NOT_ALLOWED_ERR);
return;
}
}
}
// 5.1.1.d Prompt the user for consent to create a new credential. The
// prompt for obtaining this consent is shown by the authenticator if it has
// its own output capability, or by the user agent otherwise. If the user
// denies consent, return an error code equivalent to NotAllowedError and
// terminate the operation.
// 5.1.1.d Once user consent has been obtained, generate a new credential
// object
// 5.1.1.e If any error occurred while creating the new credential object,
// return an error code equivalent to UnknownError and terminate the
// operation.
// 5.1.1.f Process all the supported extensions requested by the client, and
// generate an attestation statement. If no authority key is available to
// sign such an attestation statement, then the authenticator performs self
// attestation of the credential with its own private key. For more details
// on attestation, see §5.3 Credential Attestation Statements.
// No extensions are supported
// 4.1.1.11 While issuedRequests is not empty, perform the following actions
// depending upon the adjustedTimeout timer and responses from the
// authenticators:
// 4.1.1.11.a If the adjustedTimeout timer expires, then for each entry in
// issuedRequests invoke the authenticatorCancel operation on that
// authenticator and remove its entry from the list.
uint8_t* buffer;
uint32_t bufferlen;
nsresult rv = aToken->Register(aRpIdHash.Elements(), aRpIdHash.Length(),
aClientDataHash.Elements(),
aClientDataHash.Length(), &buffer, &bufferlen);
// 4.1.1.11.b If any authenticator returns a status indicating that the user
// cancelled the operation, delete that authenticator’s entry from
// issuedRequests. For each remaining entry in issuedRequests invoke the
// authenticatorCancel operation on that authenticator and remove its entry
// from the list.
// 4.1.1.11.c If any authenticator returns an error status, delete the
// corresponding entry from issuedRequests.
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(NS_ERROR_DOM_UNKNOWN_ERR);
return;
}
MOZ_ASSERT(buffer);
CryptoBuffer regData;
if (NS_WARN_IF(!regData.Assign(buffer, bufferlen))) {
free(buffer);
aRequest->SetFailure(NS_ERROR_OUT_OF_MEMORY);
return;
}
free(buffer);
// Decompose the U2F registration packet
CryptoBuffer pubKeyBuf;
CryptoBuffer keyHandleBuf;
CryptoBuffer attestationCertBuf;
CryptoBuffer signatureBuf;
rv = U2FDecomposeRegistrationResponse(regData, pubKeyBuf, keyHandleBuf,
attestationCertBuf, signatureBuf);
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
// Sign the aClientDataHash explicitly to get the format needed for
// the AuthenticatorData parameter of WebAuthnAttestation. This might
// be temporary while the spec settles down how to incorporate U2F.
rv = aToken->Sign(aRpIdHash.Elements(), aRpIdHash.Length(),
aClientDataHash.Elements(), aClientDataHash.Length(),
keyHandleBuf.Elements(), keyHandleBuf.Length(), &buffer,
&bufferlen);
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
MOZ_ASSERT(buffer);
CryptoBuffer signatureData;
if (NS_WARN_IF(!signatureData.Assign(buffer, bufferlen))) {
free(buffer);
aRequest->SetFailure(NS_ERROR_OUT_OF_MEMORY);
return;
}
free(buffer);
CryptoBuffer clientDataBuf;
if (!clientDataBuf.Assign(aClientData)) {
aRequest->SetFailure(NS_ERROR_OUT_OF_MEMORY);
return;
}
CryptoBuffer authenticatorDataBuf;
rv = U2FAssembleAuthenticatorData(authenticatorDataBuf, aRpIdHash,
signatureData);
if (NS_WARN_IF(NS_FAILED(rv))) {
aRequest->SetFailure(rv);
return;
}
// 4.1.1.11.d If any authenticator indicates success:
// 4.1.1.11.d.1 Remove this authenticator’s entry from issuedRequests.
// 4.1.1.11.d.2 Create a new ScopedCredentialInfo object named value and
// populate its fields with the values returned from the authenticator as well
// as the clientDataJSON computed earlier.
RefPtr<ScopedCredential> credential = new ScopedCredential(this);
credential->SetType(ScopedCredentialType::ScopedCred);
credential->SetId(keyHandleBuf);
RefPtr<WebAuthnAttestation> attestation = new WebAuthnAttestation(this);
attestation->SetFormat(NS_LITERAL_STRING("u2f"));
attestation->SetClientData(clientDataBuf);
attestation->SetAuthenticatorData(authenticatorDataBuf);
attestation->SetAttestation(regData);
CredentialPtr info = new ScopedCredentialInfo(this);
info->SetCredential(credential);
info->SetAttestation(attestation);
// 4.1.1.11.d.3 For each remaining entry in issuedRequests invoke the
// authenticatorCancel operation on that authenticator and remove its entry
// from the list.
// 4.1.1.11.d.4 Resolve promise with value and terminate this algorithm.
aRequest->SetSuccess(info);
}
static nsresult
U2FDecomposeRegistrationResponse(const CryptoBuffer& aResponse,
/* out */ CryptoBuffer& aPubKeyBuf,
/* out */ CryptoBuffer& aKeyHandleBuf,
/* out */ CryptoBuffer& aAttestationCertBuf,
/* out */ CryptoBuffer& aSignatureBuf)
{
// U2F v1.1 Format via
// http://fidoalliance.org/specs/fido-u2f-v1.1-id-20160915/fido-u2f-raw-message-formats-v1.1-id-20160915.html
//
// Bytes Value
// 1 0x05
// 65 public key
// 1 key handle length
// * key handle
// ASN.1 attestation certificate
// * attestation signature
pkix::Input u2fResponse;
u2fResponse.Init(aResponse.Elements(), aResponse.Length());
pkix::Reader input(u2fResponse);
uint8_t b;
if (input.Read(b) != pkix::Success) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
if (b != 0x05) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
nsresult rv = ReadToCryptoBuffer(input, aPubKeyBuf, 65);
if (NS_FAILED(rv)) {
return rv;
}
uint8_t handleLen;
if (input.Read(handleLen) != pkix::Success) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
rv = ReadToCryptoBuffer(input, aKeyHandleBuf, handleLen);
if (NS_FAILED(rv)) {
return rv;
}
// We have to parse the ASN.1 SEQUENCE on the outside to determine the cert's
// length.
pkix::Input cert;
if (pkix::der::ExpectTagAndGetValue(input, pkix::der::SEQUENCE, cert)
!= pkix::Success) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
pkix::Reader certInput(cert);
rv = ReadToCryptoBuffer(certInput, aAttestationCertBuf, cert.GetLength());
if (NS_FAILED(rv)) {
return rv;
}
// The remainder of u2fResponse is the signature
pkix::Input u2fSig;
input.SkipToEnd(u2fSig);
pkix::Reader sigInput(u2fSig);
rv = ReadToCryptoBuffer(sigInput, aSignatureBuf, u2fSig.GetLength());
if (NS_FAILED(rv)) {
return rv;
}
return NS_OK;
}