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b1cbda2eea
Summary: FIDO U2F's specification says that when the wrong security key responds to a signature, or when an already-registered key exists, that the UA should return error code 4, DEVICE_INELIGIBLE. We used to do that, but adjusted some things for WebAuthn and now we don't. This changes the soft token to return that at the appropriate times, and updates the expectations of U2F.cpp that it should use InvalidStateError as the signal to reutrn DEVICE_INELIGIBLE. Also, note that WebAuthn's specification says that if any authenticator returns "InvalidStateError" that it should be propagated, as it indicates that the authenticator obtained user consent and failed to complete its job [1]. This change to the Soft Token affects the WebAuthn tests, but in a good way. Reading the WebAuthn spec, we should not be returning NotAllowedError when there is consent from the user via the token (which the softtoken always deliveres). As such, this adjusts the affected WebAuthn tests, and adds a couple useful checks to test_webauthn_get_assertion.html for future purposes. [1] https://w3c.github.io/webauthn/#createCredential section 5.1.3 "Create a new credential", Step 20, Note 2: "If any authenticator returns an error status equivalent to "InvalidStateError"..." Test Plan: https://treeherder.mozilla.org/#/jobs?repo=try&revision=f2fc930f7fc8eea69b1ebc96748fe95e150a92a4 Reviewers: ttaubert Bug #: 1460767 Differential Revision: https://phabricator.services.mozilla.com/D1269 --HG-- extra : transplant_source : M%5B%93%81%29%7E%B2%E8%24%05%A6%96%8BUN%C9%FB%3E%B3h
882 lines
32 KiB
C++
882 lines
32 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "mozilla/dom/U2FSoftTokenManager.h"
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#include "CryptoBuffer.h"
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#include "mozilla/Base64.h"
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#include "mozilla/Casting.h"
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#include "nsNSSComponent.h"
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#include "nsThreadUtils.h"
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#include "pk11pub.h"
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#include "prerror.h"
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#include "secerr.h"
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#include "WebCryptoCommon.h"
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#define PREF_U2F_NSSTOKEN_COUNTER "security.webauth.softtoken_counter"
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namespace mozilla {
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namespace dom {
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using namespace mozilla;
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using mozilla::dom::CreateECParamsForCurve;
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const nsCString U2FSoftTokenManager::mSecretNickname =
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NS_LITERAL_CSTRING("U2F_NSSTOKEN");
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namespace {
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NS_NAMED_LITERAL_CSTRING(kAttestCertSubjectName, "CN=Firefox U2F Soft Token");
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// This U2F-compatible soft token uses FIDO U2F-compatible ECDSA keypairs
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// on the SEC_OID_SECG_EC_SECP256R1 curve. When asked to Register, it will
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// generate and return a new keypair KP, where the private component is wrapped
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// using AES-KW with the 128-bit mWrappingKey to make an opaque "key handle".
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// In other words, Register yields { KP_pub, AES-KW(KP_priv, key=mWrappingKey) }
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//
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// The value mWrappingKey is long-lived; it is persisted as part of the NSS DB
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// for the current profile. The attestation certificates that are produced are
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// ephemeral to counteract profiling. They have little use for a soft-token
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// at any rate, but are required by the specification.
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const uint32_t kParamLen = 32;
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const uint32_t kPublicKeyLen = 65;
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const uint32_t kWrappedKeyBufLen = 256;
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const uint32_t kWrappingKeyByteLen = 128/8;
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const uint32_t kSaltByteLen = 64/8;
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const uint32_t kVersion1KeyHandleLen = 162;
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NS_NAMED_LITERAL_STRING(kEcAlgorithm, WEBCRYPTO_NAMED_CURVE_P256);
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const PRTime kOneDay = PRTime(PR_USEC_PER_SEC)
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* PRTime(60) // sec
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* PRTime(60) // min
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* PRTime(24); // hours
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const PRTime kExpirationSlack = kOneDay; // Pre-date for clock skew
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const PRTime kExpirationLife = kOneDay;
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static mozilla::LazyLogModule gNSSTokenLog("webauth_u2f");
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enum SoftTokenHandle {
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Version1 = 0,
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};
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}
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U2FSoftTokenManager::U2FSoftTokenManager(uint32_t aCounter)
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: mInitialized(false),
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mCounter(aCounter)
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{}
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/**
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* Gets the first key with the given nickname from the given slot. Any other
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* keys found are not returned.
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* PK11_GetNextSymKey() should not be called on the returned key.
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*
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* @param aSlot Slot to search.
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* @param aNickname Nickname the key should have.
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* @return The first key found. nullptr if no key could be found.
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*/
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static UniquePK11SymKey
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GetSymKeyByNickname(const UniquePK11SlotInfo& aSlot, const nsCString& aNickname)
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{
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MOZ_ASSERT(aSlot);
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if (NS_WARN_IF(!aSlot)) {
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return nullptr;
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}
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug,
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("Searching for a symmetric key named %s", aNickname.get()));
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UniquePK11SymKey keyListHead(
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PK11_ListFixedKeysInSlot(aSlot.get(), const_cast<char*>(aNickname.get()),
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/* wincx */ nullptr));
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if (NS_WARN_IF(!keyListHead)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug, ("Symmetric key not found."));
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return nullptr;
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}
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// Sanity check PK11_ListFixedKeysInSlot() only returns keys with the correct
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// nickname.
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MOZ_ASSERT(aNickname ==
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UniquePORTString(PK11_GetSymKeyNickname(keyListHead.get())).get());
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug, ("Symmetric key found!"));
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// Free any remaining keys in the key list.
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UniquePK11SymKey freeKey(PK11_GetNextSymKey(keyListHead.get()));
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while (freeKey) {
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freeKey = UniquePK11SymKey(PK11_GetNextSymKey(freeKey.get()));
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}
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return keyListHead;
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}
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static nsresult
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GenEcKeypair(const UniquePK11SlotInfo& aSlot,
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/*out*/ UniqueSECKEYPrivateKey& aPrivKey,
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/*out*/ UniqueSECKEYPublicKey& aPubKey)
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{
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MOZ_ASSERT(aSlot);
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if (NS_WARN_IF(!aSlot)) {
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return NS_ERROR_INVALID_ARG;
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}
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UniquePLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE));
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if (NS_WARN_IF(!arena)) {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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// Set the curve parameters; keyParams belongs to the arena memory space
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SECItem* keyParams = CreateECParamsForCurve(kEcAlgorithm, arena.get());
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if (NS_WARN_IF(!keyParams)) {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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// Generate a key pair
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CK_MECHANISM_TYPE mechanism = CKM_EC_KEY_PAIR_GEN;
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SECKEYPublicKey* pubKeyRaw;
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aPrivKey = UniqueSECKEYPrivateKey(
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PK11_GenerateKeyPair(aSlot.get(), mechanism, keyParams, &pubKeyRaw,
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/* ephemeral */ false, false,
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/* wincx */ nullptr));
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aPubKey = UniqueSECKEYPublicKey(pubKeyRaw);
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pubKeyRaw = nullptr;
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if (NS_WARN_IF(!aPrivKey.get() || !aPubKey.get())) {
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return NS_ERROR_FAILURE;
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}
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// Check that the public key has the correct length
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if (NS_WARN_IF(aPubKey->u.ec.publicValue.len != kPublicKeyLen)) {
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return NS_ERROR_FAILURE;
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}
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return NS_OK;
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}
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nsresult
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U2FSoftTokenManager::GetOrCreateWrappingKey(const UniquePK11SlotInfo& aSlot)
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{
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MOZ_ASSERT(aSlot);
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if (NS_WARN_IF(!aSlot)) {
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return NS_ERROR_INVALID_ARG;
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}
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// Search for an existing wrapping key. If we find it,
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// store it for later and mark ourselves initialized.
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mWrappingKey = GetSymKeyByNickname(aSlot, mSecretNickname);
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if (mWrappingKey) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug, ("U2F Soft Token Key found."));
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mInitialized = true;
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return NS_OK;
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}
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MOZ_LOG(gNSSTokenLog, LogLevel::Info,
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("No keys found. Generating new U2F Soft Token wrapping key."));
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// We did not find an existing wrapping key, so we generate one in the
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// persistent database (e.g, Token).
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mWrappingKey = UniquePK11SymKey(
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PK11_TokenKeyGenWithFlags(aSlot.get(), CKM_AES_KEY_GEN,
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/* default params */ nullptr,
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kWrappingKeyByteLen,
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/* empty keyid */ nullptr,
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/* flags */ CKF_WRAP | CKF_UNWRAP,
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/* attributes */ PK11_ATTR_TOKEN |
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PK11_ATTR_PRIVATE,
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/* wincx */ nullptr));
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if (NS_WARN_IF(!mWrappingKey)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to store wrapping key, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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SECStatus srv = PK11_SetSymKeyNickname(mWrappingKey.get(),
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mSecretNickname.get());
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if (NS_WARN_IF(srv != SECSuccess)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to set nickname, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug,
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("Key stored, nickname set to %s.", mSecretNickname.get()));
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GetMainThreadEventTarget()->Dispatch(NS_NewRunnableFunction(
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"dom::U2FSoftTokenManager::GetOrCreateWrappingKey",
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[] () {
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MOZ_ASSERT(NS_IsMainThread());
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Preferences::SetUint(PREF_U2F_NSSTOKEN_COUNTER, 0);
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}));
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return NS_OK;
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}
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static nsresult
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GetAttestationCertificate(const UniquePK11SlotInfo& aSlot,
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/*out*/ UniqueSECKEYPrivateKey& aAttestPrivKey,
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/*out*/ UniqueCERTCertificate& aAttestCert)
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{
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MOZ_ASSERT(aSlot);
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if (NS_WARN_IF(!aSlot)) {
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return NS_ERROR_INVALID_ARG;
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}
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UniqueSECKEYPublicKey pubKey;
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// Construct an ephemeral keypair for this Attestation Certificate
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nsresult rv = GenEcKeypair(aSlot, aAttestPrivKey, pubKey);
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if (NS_WARN_IF(NS_FAILED(rv) || !aAttestPrivKey || !pubKey)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to gen keypair, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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// Construct the Attestation Certificate itself
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UniqueCERTName subjectName(CERT_AsciiToName(kAttestCertSubjectName.get()));
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if (NS_WARN_IF(!subjectName)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to set subject name, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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UniqueCERTSubjectPublicKeyInfo spki(
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SECKEY_CreateSubjectPublicKeyInfo(pubKey.get()));
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if (NS_WARN_IF(!spki)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to set SPKI, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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UniqueCERTCertificateRequest certreq(
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CERT_CreateCertificateRequest(subjectName.get(), spki.get(), nullptr));
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if (NS_WARN_IF(!certreq)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to gen CSR, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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PRTime now = PR_Now();
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PRTime notBefore = now - kExpirationSlack;
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PRTime notAfter = now + kExpirationLife;
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UniqueCERTValidity validity(CERT_CreateValidity(notBefore, notAfter));
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if (NS_WARN_IF(!validity)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to gen validity, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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unsigned long serial;
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unsigned char* serialBytes =
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mozilla::BitwiseCast<unsigned char*, unsigned long*>(&serial);
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SECStatus srv = PK11_GenerateRandomOnSlot(aSlot.get(), serialBytes,
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sizeof(serial));
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if (NS_WARN_IF(srv != SECSuccess)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to gen serial, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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// Ensure that the most significant bit isn't set (which would
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// indicate a negative number, which isn't valid for serial
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// numbers).
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serialBytes[0] &= 0x7f;
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// Also ensure that the least significant bit on the most
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// significant byte is set (to prevent a leading zero byte,
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// which also wouldn't be valid).
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serialBytes[0] |= 0x01;
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aAttestCert = UniqueCERTCertificate(
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CERT_CreateCertificate(serial, subjectName.get(), validity.get(),
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certreq.get()));
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if (NS_WARN_IF(!aAttestCert)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to gen certificate, NSS error #%d", PORT_GetError()));
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return NS_ERROR_FAILURE;
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}
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PLArenaPool* arena = aAttestCert->arena;
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srv = SECOID_SetAlgorithmID(arena, &aAttestCert->signature,
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SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE,
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/* wincx */ nullptr);
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if (NS_WARN_IF(srv != SECSuccess)) {
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return NS_ERROR_FAILURE;
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}
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// Set version to X509v3.
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*(aAttestCert->version.data) = SEC_CERTIFICATE_VERSION_3;
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aAttestCert->version.len = 1;
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SECItem innerDER = { siBuffer, nullptr, 0 };
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if (NS_WARN_IF(!SEC_ASN1EncodeItem(arena, &innerDER, aAttestCert.get(),
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SEC_ASN1_GET(CERT_CertificateTemplate)))) {
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return NS_ERROR_FAILURE;
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}
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SECItem* signedCert = PORT_ArenaZNew(arena, SECItem);
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if (NS_WARN_IF(!signedCert)) {
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return NS_ERROR_FAILURE;
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}
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srv = SEC_DerSignData(arena, signedCert, innerDER.data, innerDER.len,
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aAttestPrivKey.get(),
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SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE);
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if (NS_WARN_IF(srv != SECSuccess)) {
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return NS_ERROR_FAILURE;
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}
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aAttestCert->derCert = *signedCert;
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug,
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("U2F Soft Token attestation certificate generated."));
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return NS_OK;
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}
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// Set up the context for the soft U2F Token. This is called by NSS
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// initialization.
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nsresult
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U2FSoftTokenManager::Init()
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{
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// If we've already initialized, just return.
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if (mInitialized) {
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return NS_OK;
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}
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UniquePK11SlotInfo slot(PK11_GetInternalKeySlot());
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MOZ_ASSERT(slot.get());
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// Search for an existing wrapping key, or create one.
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nsresult rv = GetOrCreateWrappingKey(slot);
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if (NS_WARN_IF(NS_FAILED(rv))) {
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return rv;
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}
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mInitialized = true;
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MOZ_LOG(gNSSTokenLog, LogLevel::Debug, ("U2F Soft Token initialized."));
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return NS_OK;
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}
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// Convert a Private Key object into an opaque key handle, using AES Key Wrap
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// with the long-lived aPersistentKey mixed with aAppParam to convert aPrivKey.
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// The key handle's format is version || saltLen || salt || wrappedPrivateKey
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static UniqueSECItem
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KeyHandleFromPrivateKey(const UniquePK11SlotInfo& aSlot,
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const UniquePK11SymKey& aPersistentKey,
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uint8_t* aAppParam, uint32_t aAppParamLen,
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const UniqueSECKEYPrivateKey& aPrivKey)
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{
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MOZ_ASSERT(aSlot);
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MOZ_ASSERT(aPersistentKey);
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MOZ_ASSERT(aAppParam);
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MOZ_ASSERT(aPrivKey);
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if (NS_WARN_IF(!aSlot || !aPersistentKey || !aPrivKey || !aAppParam)) {
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return nullptr;
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}
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// Generate a random salt
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uint8_t saltParam[kSaltByteLen];
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SECStatus srv = PK11_GenerateRandomOnSlot(aSlot.get(), saltParam,
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sizeof(saltParam));
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if (NS_WARN_IF(srv != SECSuccess)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to generate a salt, NSS error #%d", PORT_GetError()));
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return nullptr;
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}
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// Prepare the HKDF (https://tools.ietf.org/html/rfc5869)
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CK_NSS_HKDFParams hkdfParams = { true, saltParam, sizeof(saltParam),
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true, aAppParam, aAppParamLen };
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SECItem kdfParams = { siBuffer, (unsigned char*)&hkdfParams,
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sizeof(hkdfParams) };
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// Derive a wrapping key from aPersistentKey, the salt, and the aAppParam.
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// CKM_AES_KEY_GEN and CKA_WRAP are key type and usage attributes of the
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// derived symmetric key and don't matter because we ignore them anyway.
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UniquePK11SymKey wrapKey(PK11_Derive(aPersistentKey.get(), CKM_NSS_HKDF_SHA256,
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&kdfParams, CKM_AES_KEY_GEN, CKA_WRAP,
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kWrappingKeyByteLen));
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if (NS_WARN_IF(!wrapKey.get())) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to derive a wrapping key, NSS error #%d", PORT_GetError()));
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return nullptr;
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}
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UniqueSECItem wrappedKey(::SECITEM_AllocItem(/* default arena */ nullptr,
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/* no buffer */ nullptr,
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kWrappedKeyBufLen));
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if (NS_WARN_IF(!wrappedKey)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning, ("Failed to allocate memory"));
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return nullptr;
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}
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UniqueSECItem param(PK11_ParamFromIV(CKM_NSS_AES_KEY_WRAP_PAD,
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/* default IV */ nullptr ));
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srv = PK11_WrapPrivKey(aSlot.get(), wrapKey.get(), aPrivKey.get(),
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CKM_NSS_AES_KEY_WRAP_PAD, param.get(), wrappedKey.get(),
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/* wincx */ nullptr);
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if (NS_WARN_IF(srv != SECSuccess)) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
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("Failed to wrap U2F key, NSS error #%d", PORT_GetError()));
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return nullptr;
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}
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// Concatenate the salt and the wrapped Private Key together
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mozilla::dom::CryptoBuffer keyHandleBuf;
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if (NS_WARN_IF(!keyHandleBuf.SetCapacity(wrappedKey.get()->len + sizeof(saltParam) + 2,
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mozilla::fallible))) {
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MOZ_LOG(gNSSTokenLog, LogLevel::Warning, ("Failed to allocate memory"));
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return nullptr;
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}
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// It's OK to ignore the return values here because we're writing into
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// pre-allocated space
|
|
keyHandleBuf.AppendElement(SoftTokenHandle::Version1, mozilla::fallible);
|
|
keyHandleBuf.AppendElement(sizeof(saltParam), mozilla::fallible);
|
|
keyHandleBuf.AppendElements(saltParam, sizeof(saltParam), mozilla::fallible);
|
|
keyHandleBuf.AppendSECItem(wrappedKey.get());
|
|
|
|
UniqueSECItem keyHandle(::SECITEM_AllocItem(nullptr, nullptr, 0));
|
|
if (NS_WARN_IF(!keyHandle)) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning, ("Failed to allocate memory"));
|
|
return nullptr;
|
|
}
|
|
|
|
if (NS_WARN_IF(!keyHandleBuf.ToSECItem(/* default arena */ nullptr, keyHandle.get()))) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning, ("Failed to allocate memory"));
|
|
return nullptr;
|
|
}
|
|
return keyHandle;
|
|
}
|
|
|
|
// Convert an opaque key handle aKeyHandle back into a Private Key object, using
|
|
// the long-lived aPersistentKey mixed with aAppParam and the AES Key Wrap
|
|
// algorithm.
|
|
static UniqueSECKEYPrivateKey
|
|
PrivateKeyFromKeyHandle(const UniquePK11SlotInfo& aSlot,
|
|
const UniquePK11SymKey& aPersistentKey,
|
|
uint8_t* aKeyHandle, uint32_t aKeyHandleLen,
|
|
uint8_t* aAppParam, uint32_t aAppParamLen)
|
|
{
|
|
MOZ_ASSERT(aSlot);
|
|
MOZ_ASSERT(aPersistentKey);
|
|
MOZ_ASSERT(aKeyHandle);
|
|
MOZ_ASSERT(aAppParam);
|
|
MOZ_ASSERT(aAppParamLen == SHA256_LENGTH);
|
|
if (NS_WARN_IF(!aSlot || !aPersistentKey || !aKeyHandle || !aAppParam ||
|
|
aAppParamLen != SHA256_LENGTH)) {
|
|
return nullptr;
|
|
}
|
|
|
|
// As we only support one key format ourselves (right now), fail early if
|
|
// we aren't that length
|
|
if (NS_WARN_IF(aKeyHandleLen != kVersion1KeyHandleLen)) {
|
|
return nullptr;
|
|
}
|
|
|
|
if (NS_WARN_IF(aKeyHandle[0] != SoftTokenHandle::Version1)) {
|
|
// Unrecognized version
|
|
return nullptr;
|
|
}
|
|
|
|
uint8_t saltLen = aKeyHandle[1];
|
|
uint8_t* saltPtr = aKeyHandle + 2;
|
|
if (NS_WARN_IF(saltLen != kSaltByteLen)) {
|
|
return nullptr;
|
|
}
|
|
|
|
// Prepare the HKDF (https://tools.ietf.org/html/rfc5869)
|
|
CK_NSS_HKDFParams hkdfParams = { true, saltPtr, saltLen,
|
|
true, aAppParam, aAppParamLen };
|
|
SECItem kdfParams = { siBuffer, (unsigned char*)&hkdfParams,
|
|
sizeof(hkdfParams) };
|
|
|
|
// Derive a wrapping key from aPersistentKey, the salt, and the aAppParam.
|
|
// CKM_AES_KEY_GEN and CKA_WRAP are key type and usage attributes of the
|
|
// derived symmetric key and don't matter because we ignore them anyway.
|
|
UniquePK11SymKey wrapKey(PK11_Derive(aPersistentKey.get(), CKM_NSS_HKDF_SHA256,
|
|
&kdfParams, CKM_AES_KEY_GEN, CKA_WRAP,
|
|
kWrappingKeyByteLen));
|
|
if (NS_WARN_IF(!wrapKey.get())) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
|
|
("Failed to derive a wrapping key, NSS error #%d", PORT_GetError()));
|
|
return nullptr;
|
|
}
|
|
|
|
uint8_t wrappedLen = aKeyHandleLen - saltLen - 2;
|
|
uint8_t* wrappedPtr = aKeyHandle + saltLen + 2;
|
|
|
|
ScopedAutoSECItem wrappedKeyItem(wrappedLen);
|
|
memcpy(wrappedKeyItem.data, wrappedPtr, wrappedKeyItem.len);
|
|
|
|
ScopedAutoSECItem pubKey(kPublicKeyLen);
|
|
|
|
UniqueSECItem param(PK11_ParamFromIV(CKM_NSS_AES_KEY_WRAP_PAD,
|
|
/* default IV */ nullptr ));
|
|
|
|
CK_ATTRIBUTE_TYPE usages[] = { CKA_SIGN };
|
|
int usageCount = 1;
|
|
|
|
UniqueSECKEYPrivateKey unwrappedKey(
|
|
PK11_UnwrapPrivKey(aSlot.get(), wrapKey.get(), CKM_NSS_AES_KEY_WRAP_PAD,
|
|
param.get(), &wrappedKeyItem,
|
|
/* no nickname */ nullptr,
|
|
/* discard pubkey */ &pubKey,
|
|
/* not permanent */ false,
|
|
/* non-exportable */ true,
|
|
CKK_EC, usages, usageCount,
|
|
/* wincx */ nullptr));
|
|
if (NS_WARN_IF(!unwrappedKey)) {
|
|
// Not our key.
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Debug,
|
|
("Could not unwrap key handle, NSS Error #%d", PORT_GetError()));
|
|
return nullptr;
|
|
}
|
|
|
|
return unwrappedKey;
|
|
}
|
|
|
|
// IsRegistered determines if the provided key handle is usable by this token.
|
|
nsresult
|
|
U2FSoftTokenManager::IsRegistered(const nsTArray<uint8_t>& aKeyHandle,
|
|
const nsTArray<uint8_t>& aAppParam,
|
|
bool& aResult)
|
|
{
|
|
if (!mInitialized) {
|
|
nsresult rv = Init();
|
|
if (NS_WARN_IF(NS_FAILED(rv))) {
|
|
return rv;
|
|
}
|
|
}
|
|
|
|
UniquePK11SlotInfo slot(PK11_GetInternalSlot());
|
|
MOZ_ASSERT(slot.get());
|
|
|
|
// Decode the key handle
|
|
UniqueSECKEYPrivateKey privKey = PrivateKeyFromKeyHandle(slot, mWrappingKey,
|
|
const_cast<uint8_t*>(aKeyHandle.Elements()),
|
|
aKeyHandle.Length(),
|
|
const_cast<uint8_t*>(aAppParam.Elements()),
|
|
aAppParam.Length());
|
|
aResult = privKey.get() != nullptr;
|
|
return NS_OK;
|
|
}
|
|
|
|
// A U2F Register operation causes a new key pair to be generated by the token.
|
|
// The token then returns the public key of the key pair, and a handle to the
|
|
// private key, which is a fancy way of saying "key wrapped private key", as
|
|
// well as the generated attestation certificate and a signature using that
|
|
// certificate's private key.
|
|
//
|
|
// The KeyHandleFromPrivateKey and PrivateKeyFromKeyHandle methods perform
|
|
// the actual key wrap/unwrap operations.
|
|
//
|
|
// The format of the return registration data is as follows:
|
|
//
|
|
// Bytes Value
|
|
// 1 0x05
|
|
// 65 public key
|
|
// 1 key handle length
|
|
// * key handle
|
|
// ASN.1 attestation certificate
|
|
// * attestation signature
|
|
//
|
|
RefPtr<U2FRegisterPromise>
|
|
U2FSoftTokenManager::Register(const WebAuthnMakeCredentialInfo& aInfo)
|
|
{
|
|
if (!mInitialized) {
|
|
nsresult rv = Init();
|
|
if (NS_WARN_IF(NS_FAILED(rv))) {
|
|
return U2FRegisterPromise::CreateAndReject(rv, __func__);
|
|
}
|
|
}
|
|
|
|
const WebAuthnAuthenticatorSelection& sel = aInfo.AuthenticatorSelection();
|
|
|
|
// The U2F softtoken neither supports resident keys or
|
|
// user verification, nor is it a platform authenticator.
|
|
if (sel.requireResidentKey() ||
|
|
sel.requireUserVerification() ||
|
|
sel.requirePlatformAttachment()) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_DOM_NOT_ALLOWED_ERR, __func__);
|
|
}
|
|
|
|
// Optional exclusion list.
|
|
for (const WebAuthnScopedCredential& cred: aInfo.ExcludeList()) {
|
|
bool isRegistered = false;
|
|
nsresult rv = IsRegistered(cred.id(), aInfo.RpIdHash(), isRegistered);
|
|
if (NS_FAILED(rv)) {
|
|
return U2FRegisterPromise::CreateAndReject(rv, __func__);
|
|
}
|
|
if (isRegistered) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_DOM_INVALID_STATE_ERR, __func__);
|
|
}
|
|
}
|
|
|
|
// We should already have a wrapping key
|
|
MOZ_ASSERT(mWrappingKey);
|
|
|
|
UniquePK11SlotInfo slot(PK11_GetInternalSlot());
|
|
MOZ_ASSERT(slot.get());
|
|
|
|
// Construct a one-time-use Attestation Certificate
|
|
UniqueSECKEYPrivateKey attestPrivKey;
|
|
UniqueCERTCertificate attestCert;
|
|
nsresult rv = GetAttestationCertificate(slot, attestPrivKey, attestCert);
|
|
if (NS_WARN_IF(NS_FAILED(rv))) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
MOZ_ASSERT(attestCert);
|
|
MOZ_ASSERT(attestPrivKey);
|
|
|
|
// Generate a new keypair; the private will be wrapped into a Key Handle
|
|
UniqueSECKEYPrivateKey privKey;
|
|
UniqueSECKEYPublicKey pubKey;
|
|
rv = GenEcKeypair(slot, privKey, pubKey);
|
|
if (NS_WARN_IF(NS_FAILED(rv))) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
|
|
// The key handle will be the result of keywrap(privKey, key=mWrappingKey)
|
|
UniqueSECItem keyHandleItem =
|
|
KeyHandleFromPrivateKey(slot, mWrappingKey,
|
|
const_cast<uint8_t*>(aInfo.RpIdHash().Elements()),
|
|
aInfo.RpIdHash().Length(), privKey);
|
|
if (NS_WARN_IF(!keyHandleItem.get())) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
|
|
// Sign the challenge using the Attestation privkey (from attestCert)
|
|
mozilla::dom::CryptoBuffer signedDataBuf;
|
|
if (NS_WARN_IF(!signedDataBuf.SetCapacity(1 + aInfo.RpIdHash().Length() +
|
|
aInfo.ClientDataHash().Length() +
|
|
keyHandleItem->len + kPublicKeyLen,
|
|
mozilla::fallible))) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_OUT_OF_MEMORY, __func__);
|
|
}
|
|
|
|
// // It's OK to ignore the return values here because we're writing into
|
|
// // pre-allocated space
|
|
signedDataBuf.AppendElement(0x00, mozilla::fallible);
|
|
signedDataBuf.AppendElements(aInfo.RpIdHash(), mozilla::fallible);
|
|
signedDataBuf.AppendElements(aInfo.ClientDataHash(), mozilla::fallible);
|
|
signedDataBuf.AppendSECItem(keyHandleItem.get());
|
|
signedDataBuf.AppendSECItem(pubKey->u.ec.publicValue);
|
|
|
|
ScopedAutoSECItem signatureItem;
|
|
SECStatus srv = SEC_SignData(&signatureItem, signedDataBuf.Elements(),
|
|
signedDataBuf.Length(), attestPrivKey.get(),
|
|
SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE);
|
|
if (NS_WARN_IF(srv != SECSuccess)) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
|
|
("Signature failure: %d", PORT_GetError()));
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
|
|
// Serialize the registration data
|
|
mozilla::dom::CryptoBuffer registrationBuf;
|
|
if (NS_WARN_IF(!registrationBuf.SetCapacity(1 + kPublicKeyLen + 1 + keyHandleItem->len +
|
|
attestCert.get()->derCert.len +
|
|
signatureItem.len, mozilla::fallible))) {
|
|
return U2FRegisterPromise::CreateAndReject(NS_ERROR_OUT_OF_MEMORY, __func__);
|
|
}
|
|
registrationBuf.AppendElement(0x05, mozilla::fallible);
|
|
registrationBuf.AppendSECItem(pubKey->u.ec.publicValue);
|
|
registrationBuf.AppendElement(keyHandleItem->len, mozilla::fallible);
|
|
registrationBuf.AppendSECItem(keyHandleItem.get());
|
|
registrationBuf.AppendSECItem(attestCert.get()->derCert);
|
|
registrationBuf.AppendSECItem(signatureItem);
|
|
|
|
// Will be set by the U2FTokenManager.
|
|
bool directAttestationPermitted = false;
|
|
WebAuthnMakeCredentialResult result((nsTArray<uint8_t>(registrationBuf)),
|
|
directAttestationPermitted);
|
|
return U2FRegisterPromise::CreateAndResolve(Move(result), __func__);
|
|
}
|
|
|
|
bool
|
|
U2FSoftTokenManager::FindRegisteredKeyHandle(const nsTArray<nsTArray<uint8_t>>& aAppIds,
|
|
const nsTArray<WebAuthnScopedCredential>& aCredentials,
|
|
/*out*/ nsTArray<uint8_t>& aKeyHandle,
|
|
/*out*/ nsTArray<uint8_t>& aAppId)
|
|
{
|
|
for (const nsTArray<uint8_t>& app_id: aAppIds) {
|
|
for (const WebAuthnScopedCredential& cred: aCredentials) {
|
|
bool isRegistered = false;
|
|
nsresult rv = IsRegistered(cred.id(), app_id, isRegistered);
|
|
if (NS_SUCCEEDED(rv) && isRegistered) {
|
|
aKeyHandle.Assign(cred.id());
|
|
aAppId.Assign(app_id);
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// A U2F Sign operation creates a signature over the "param" arguments (plus
|
|
// some other stuff) using the private key indicated in the key handle argument.
|
|
//
|
|
// The format of the signed data is as follows:
|
|
//
|
|
// 32 Application parameter
|
|
// 1 User presence (0x01)
|
|
// 4 Counter
|
|
// 32 Challenge parameter
|
|
//
|
|
// The format of the signature data is as follows:
|
|
//
|
|
// 1 User presence
|
|
// 4 Counter
|
|
// * Signature
|
|
//
|
|
RefPtr<U2FSignPromise>
|
|
U2FSoftTokenManager::Sign(const WebAuthnGetAssertionInfo& aInfo)
|
|
{
|
|
if (!mInitialized) {
|
|
nsresult rv = Init();
|
|
if (NS_WARN_IF(NS_FAILED(rv))) {
|
|
return U2FSignPromise::CreateAndReject(rv, __func__);
|
|
}
|
|
}
|
|
|
|
// The U2F softtoken doesn't support user verification.
|
|
if (aInfo.RequireUserVerification()) {
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_DOM_NOT_ALLOWED_ERR, __func__);
|
|
}
|
|
|
|
nsTArray<nsTArray<uint8_t>> appIds;
|
|
appIds.AppendElement(aInfo.RpIdHash());
|
|
|
|
// Process extensions.
|
|
for (const WebAuthnExtension& ext: aInfo.Extensions()) {
|
|
if (ext.type() == WebAuthnExtension::TWebAuthnExtensionAppId) {
|
|
appIds.AppendElement(ext.get_WebAuthnExtensionAppId().AppId());
|
|
}
|
|
}
|
|
|
|
nsTArray<uint8_t> chosenAppId;
|
|
nsTArray<uint8_t> keyHandle;
|
|
|
|
// Fail if we can't find a valid key handle.
|
|
if (!FindRegisteredKeyHandle(appIds, aInfo.AllowList(), keyHandle, chosenAppId)) {
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_DOM_INVALID_STATE_ERR, __func__);
|
|
}
|
|
|
|
MOZ_ASSERT(mWrappingKey);
|
|
|
|
UniquePK11SlotInfo slot(PK11_GetInternalSlot());
|
|
MOZ_ASSERT(slot.get());
|
|
|
|
if (NS_WARN_IF((aInfo.ClientDataHash().Length() != kParamLen) ||
|
|
(chosenAppId.Length() != kParamLen))) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
|
|
("Parameter lengths are wrong! challenge=%d app=%d expected=%d",
|
|
(uint32_t)aInfo.ClientDataHash().Length(),
|
|
(uint32_t)chosenAppId.Length(), kParamLen));
|
|
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_ILLEGAL_VALUE, __func__);
|
|
}
|
|
|
|
// Decode the key handle
|
|
UniqueSECKEYPrivateKey privKey =
|
|
PrivateKeyFromKeyHandle(slot, mWrappingKey,
|
|
const_cast<uint8_t*>(keyHandle.Elements()),
|
|
keyHandle.Length(),
|
|
const_cast<uint8_t*>(chosenAppId.Elements()),
|
|
chosenAppId.Length());
|
|
if (NS_WARN_IF(!privKey.get())) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning, ("Couldn't get the priv key!"));
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
|
|
// Increment the counter and turn it into a SECItem
|
|
mCounter += 1;
|
|
ScopedAutoSECItem counterItem(4);
|
|
counterItem.data[0] = (mCounter >> 24) & 0xFF;
|
|
counterItem.data[1] = (mCounter >> 16) & 0xFF;
|
|
counterItem.data[2] = (mCounter >> 8) & 0xFF;
|
|
counterItem.data[3] = (mCounter >> 0) & 0xFF;
|
|
uint32_t counter = mCounter;
|
|
GetMainThreadEventTarget()->Dispatch(NS_NewRunnableFunction(
|
|
"dom::U2FSoftTokenManager::Sign",
|
|
[counter] () {
|
|
MOZ_ASSERT(NS_IsMainThread());
|
|
Preferences::SetUint(PREF_U2F_NSSTOKEN_COUNTER, counter);
|
|
}));
|
|
|
|
// Compute the signature
|
|
mozilla::dom::CryptoBuffer signedDataBuf;
|
|
if (NS_WARN_IF(!signedDataBuf.SetCapacity(1 + 4 + (2 * kParamLen), mozilla::fallible))) {
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_OUT_OF_MEMORY, __func__);
|
|
}
|
|
|
|
// It's OK to ignore the return values here because we're writing into
|
|
// pre-allocated space
|
|
signedDataBuf.AppendElements(chosenAppId.Elements(),
|
|
chosenAppId.Length(),
|
|
mozilla::fallible);
|
|
signedDataBuf.AppendElement(0x01, mozilla::fallible);
|
|
signedDataBuf.AppendSECItem(counterItem);
|
|
signedDataBuf.AppendElements(aInfo.ClientDataHash().Elements(),
|
|
aInfo.ClientDataHash().Length(),
|
|
mozilla::fallible);
|
|
|
|
if (MOZ_LOG_TEST(gNSSTokenLog, LogLevel::Debug)) {
|
|
nsAutoCString base64;
|
|
nsresult rv = Base64URLEncode(signedDataBuf.Length(), signedDataBuf.Elements(),
|
|
Base64URLEncodePaddingPolicy::Omit, base64);
|
|
if (NS_WARN_IF(NS_FAILED(rv))) {
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Debug,
|
|
("U2F Token signing bytes (base64): %s", base64.get()));
|
|
}
|
|
|
|
ScopedAutoSECItem signatureItem;
|
|
SECStatus srv = SEC_SignData(&signatureItem, signedDataBuf.Elements(),
|
|
signedDataBuf.Length(), privKey.get(),
|
|
SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE);
|
|
if (NS_WARN_IF(srv != SECSuccess)) {
|
|
MOZ_LOG(gNSSTokenLog, LogLevel::Warning,
|
|
("Signature failure: %d", PORT_GetError()));
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
|
|
}
|
|
|
|
// Assemble the signature data into a buffer for return
|
|
mozilla::dom::CryptoBuffer signatureBuf;
|
|
if (NS_WARN_IF(!signatureBuf.SetCapacity(1 + counterItem.len + signatureItem.len,
|
|
mozilla::fallible))) {
|
|
return U2FSignPromise::CreateAndReject(NS_ERROR_OUT_OF_MEMORY, __func__);
|
|
}
|
|
|
|
// It's OK to ignore the return values here because we're writing into
|
|
// pre-allocated space
|
|
signatureBuf.AppendElement(0x01, mozilla::fallible);
|
|
signatureBuf.AppendSECItem(counterItem);
|
|
signatureBuf.AppendSECItem(signatureItem);
|
|
|
|
nsTArray<uint8_t> signature(signatureBuf);
|
|
nsTArray<WebAuthnExtensionResult> extensions;
|
|
|
|
if (chosenAppId != aInfo.RpIdHash()) {
|
|
// Indicate to the RP that we used the FIDO appId.
|
|
extensions.AppendElement(WebAuthnExtensionResultAppId(true));
|
|
}
|
|
|
|
WebAuthnGetAssertionResult result(chosenAppId, keyHandle, signature, extensions);
|
|
return U2FSignPromise::CreateAndResolve(Move(result), __func__);
|
|
}
|
|
|
|
void
|
|
U2FSoftTokenManager::Cancel()
|
|
{
|
|
// This implementation is sync, requests can't be aborted.
|
|
}
|
|
|
|
}
|
|
}
|