identity: Add support for setting minimum validity period for AuthKey.
This change adds support for specifying that an AuthKey should be
replaced if it's going to expire within a certain amount of time
configurable by the application. This also adds a way for the
application to learn about the expiration time of currently configured
AuthKeys.
Combined these two changes allow an application to get a perfect
picture of which AuthKeys are available, when they expire, and allows
the application to refresh AuthKeys well ahead of expiration dates.
Also remove checking storeStaticAuthenticationDataWithExpiration() is
only available on HAL version 3 and later (feature version 202101 and
later). This works on any HAL version.
Bug: 241912421
Test: atest VtsHalIdentityTargetTest
Test: atest android.security.identity.cts
Change-Id: Ic8274088035c31f73ad61645ee5e0281b3460837
diff --git a/identity/CredentialData.cpp b/identity/CredentialData.cpp
index 2189f90..fb08333 100644
--- a/identity/CredentialData.cpp
+++ b/identity/CredentialData.cpp
@@ -117,6 +117,7 @@
map.add("entryData", std::move(encryptedBlobsMap));
map.add("authKeyCount", keyCount_);
map.add("maxUsesPerAuthKey", maxUsesPerKey_);
+ map.add("minValidTimeMillis", minValidTimeMillis_);
cppbor::Array authKeyDatasArray;
for (const AuthKeyData& data : authKeyDatas_) {
@@ -253,6 +254,7 @@
authKeyDatas_.clear();
keyCount_ = 0;
maxUsesPerKey_ = 1;
+ minValidTimeMillis_ = 0;
optional<vector<uint8_t>> data = fileGetContents(fileName_);
if (!data) {
@@ -398,6 +400,14 @@
return false;
}
maxUsesPerKey_ = number->value();
+
+ } else if (key == "minValidTimeMillis") {
+ const cppbor::Int* number = valueItem->asInt();
+ if (number == nullptr) {
+ LOG(ERROR) << "Value for minValidTimeMillis is not a number";
+ return false;
+ }
+ minValidTimeMillis_ = number->value();
}
}
@@ -479,9 +489,11 @@
// ---
-void CredentialData::setAvailableAuthenticationKeys(int keyCount, int maxUsesPerKey) {
+void CredentialData::setAvailableAuthenticationKeys(int keyCount, int maxUsesPerKey,
+ int64_t minValidTimeMillis) {
keyCount_ = keyCount;
maxUsesPerKey_ = maxUsesPerKey;
+ minValidTimeMillis_ = minValidTimeMillis;
// If growing the number of auth keys (prevKeyCount < keyCount_ case) we'll add
// new AuthKeyData structs to |authKeyDatas_| and each struct will have empty |certificate|
@@ -499,8 +511,9 @@
return authKeyDatas_;
}
-pair<int /* keyCount */, int /*maxUsersPerKey */> CredentialData::getAvailableAuthenticationKeys() {
- return std::make_pair(keyCount_, maxUsesPerKey_);
+tuple<int /* keyCount */, int /*maxUsersPerKey */, int64_t /* minValidTimeMillis */>
+CredentialData::getAvailableAuthenticationKeys() const {
+ return std::make_tuple(keyCount_, maxUsesPerKey_, minValidTimeMillis_);
}
AuthKeyData* CredentialData::findAuthKey_(bool allowUsingExhaustedKeys,
@@ -573,9 +586,10 @@
for (AuthKeyData& data : authKeyDatas_) {
bool keyExceedUseCount = (data.useCount >= maxUsesPerKey_);
- bool keyBeyondExpirationDate = (nowMilliSeconds > data.expirationDateMillisSinceEpoch);
+ int64_t expirationDateAdjusted = data.expirationDateMillisSinceEpoch - minValidTimeMillis_;
+ bool keyBeyondAdjustedExpirationDate = (nowMilliSeconds > expirationDateAdjusted);
bool newKeyNeeded =
- (data.certificate.size() == 0) || keyExceedUseCount || keyBeyondExpirationDate;
+ (data.certificate.size() == 0) || keyExceedUseCount || keyBeyondAdjustedExpirationDate;
bool certificationPending = (data.pendingCertificate.size() > 0);
if (newKeyNeeded && !certificationPending) {
vector<uint8_t> signingKeyBlob;