Fix key parameters in authorization list (#176)

Previous commit 57b92ab wrongly encoded the key parameter `PADDING`, which should be a single SET OF INTEGER (like PURPOSE and DIGEST).

Moreover, we now include the key parameter BLOCK_MODE in KeyEntryResponse with correct order (found in key generation of `mobstore_encrypt` by GMS).

Co-authored-by: Mohammed Riad <1@mhmrdd.me>
Co-authored-by: Enginex0 <enginex0@users.noreply.github.com>

Author: 3 people

app/src/main/java/org/matrix/TEESimulator/attestation/AttestationBuilder.kt

@@ -193,9 +193,13 @@ object AttestationBuilder {
             )
         }
 
-        params.padding.forEach {
+        if (params.padding.isNotEmpty()) {
             list.add(
-                DERTaggedObject(true, AttestationConstants.TAG_PADDING, ASN1Integer(it.toLong()))
+                DERTaggedObject(
+                    true,
+                    AttestationConstants.TAG_PADDING,
+                    DERSet(params.padding.map { ASN1Integer(it.toLong()) }.toTypedArray()),
+                )
             )
         }
 

app/src/main/java/org/matrix/TEESimulator/interception/keystore/shim/KeyMintSecurityLevelInterceptor.kt

@@ -452,6 +452,9 @@ private fun KeyMintAttestation.toAuthorizations(
     }
 
     this.purpose.forEach { authList.add(createAuth(Tag.PURPOSE, KeyParameterValue.keyPurpose(it))) }
+    this.blockMode.forEach {
+        authList.add(createAuth(Tag.BLOCK_MODE, KeyParameterValue.blockMode(it)))
+    }
     this.digest.forEach { authList.add(createAuth(Tag.DIGEST, KeyParameterValue.digest(it))) }
     this.padding.forEach {
         authList.add(createAuth(Tag.PADDING, KeyParameterValue.paddingMode(it)))