identity: fix access control checks in libeic.
Also add a new libeic_test binary which has a regression test for this
vulnerability.
Bug: 190757775
Test: atest libeic_test
Test: atest VtsHalIdentityTargetTest
Test: atest CtsIdentityTestCases
Merged-In: I8344655c59930d6bf1baa4e0f8d0f60e4fc9e48d
Change-Id: I8344655c59930d6bf1baa4e0f8d0f60e4fc9e48d
diff --git a/identity/aidl/default/libeic/EicPresentation.c b/identity/aidl/default/libeic/EicPresentation.c
index 9e033b3..3d13766 100644
--- a/identity/aidl/default/libeic/EicPresentation.c
+++ b/identity/aidl/default/libeic/EicPresentation.c
@@ -633,6 +633,8 @@
// We'll need to calc and store a digest of additionalData to check that it's the same
// additionalData being passed in for every eicPresentationRetrieveEntryValue() call...
+ //
+ ctx->accessCheckOk = false;
if (!eicCborCalcEntryAdditionalData(accessControlProfileIds, numAccessControlProfileIds,
nameSpace, name, additionalDataCbor,
additionalDataCborBufSize, &additionalDataCborSize,
@@ -680,6 +682,7 @@
if (result == EIC_ACCESS_CHECK_RESULT_OK) {
eicCborAppendString(&ctx->cbor, name);
+ ctx->accessCheckOk = true;
}
return result;
}
@@ -702,10 +705,15 @@
calculatedSha256)) {
return false;
}
+
if (eicCryptoMemCmp(calculatedSha256, ctx->additionalDataSha256, EIC_SHA256_DIGEST_SIZE) != 0) {
eicDebug("SHA-256 mismatch of additionalData");
return false;
}
+ if (!ctx->accessCheckOk) {
+ eicDebug("Attempting to retrieve a value for which access is not granted");
+ return false;
+ }
if (!eicOpsDecryptAes128Gcm(ctx->storageKey, encryptedContent, encryptedContentSize,
additionalDataCbor, additionalDataCborSize, content)) {
diff --git a/identity/aidl/default/libeic/EicPresentation.h b/identity/aidl/default/libeic/EicPresentation.h
index 7cad068..c888049 100644
--- a/identity/aidl/default/libeic/EicPresentation.h
+++ b/identity/aidl/default/libeic/EicPresentation.h
@@ -70,6 +70,10 @@
// Set to true initialized as a test credential.
bool testCredential;
+ // Set to true if the evaluation of access control checks in
+ // eicPresentationStartRetrieveEntryValue() resulted EIC_ACCESS_CHECK_RESULT_OK
+ bool accessCheckOk;
+
// These are bitmasks indicating which of the possible 32 access control profiles are
// authorized. They are built up by eicPresentationValidateAccessControlProfile().
//