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Add new RKP root key, also simplify logic a bit #59

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Add new RKP root key, also simplify logic a bit #59

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67 changes: 31 additions & 36 deletions app/src/main/java/io/github/vvb2060/keyattestation/attestation/RootPublicKey.java
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Original file line number Diff line number Diff line change
Expand Up @@ -3,12 +3,13 @@
import android.util.Base64;
import android.util.Log;

import com.google.common.collect.ImmutableMap;
import java.io.ByteArrayInputStream;
import java.security.PublicKey;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import io.github.vvb2060.keyattestation.AppApplication;
Expand Down Expand Up @@ -39,6 +40,11 @@ public enum Status {
ixPvZtXQpUpuL12ab+9EaDK8Z4RHJYYfCT3Q5vNAXaiWQ+8PTWm2QgBR/bkwSWc+\
NpUFgNPN9PvQi8WEg5UmAGMCAwEAAQ==""";

private static final String GOOGLE_RKP_ROOT_PUBLIC_KEY = """
MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEI9ojcU7fPlsFCjxy6IRqzgeOoK0b+YsV\
9FPQywiyw8EQRTkJ9u3qwfnI4DGoSLlBqClTXJfgfCcZvs60FikNMHnu4fkRzObf\
gDkU2KNXezT9/RQ+XvNslxPHrHCowhGr""";

private static final String AOSP_ROOT_EC_PUBLIC_KEY = """
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE7l1ex+HA220Dpn7mthvsTWpdamgu\
D/9/SQ59dx9EIm29sa/6FsvHrcV30lacqrewLVQBXT5DKyqO107sSHVBpA==""";
Expand Down Expand Up @@ -67,23 +73,34 @@ public enum Status {
oiC6ldbF2uNVU3rYYSytWAJg3GFKd1l9VLDmxox58Hyw2Jmdd5VSObGiTFQ/SgKs\
n2fbQPtpGlNxgEfd6Y8=""";

private static final byte[] googleKey = Base64.decode(GOOGLE_ROOT_PUBLIC_KEY, 0);
private static final byte[] aospEcKey = Base64.decode(AOSP_ROOT_EC_PUBLIC_KEY, 0);
private static final byte[] aospRsaKey = Base64.decode(AOSP_ROOT_RSA_PUBLIC_KEY, 0);
private static final byte[] knoxSakv1Key = Base64.decode(KNOX_SAKV1_ROOT_PUBLIC_KEY, 0);
private static final byte[] knoxSakv2Key = Base64.decode(KNOX_SAKV2_ROOT_PUBLIC_KEY, 0);
private static final byte[] knoxSakmv1Key = Base64.decode(KNOX_SAKMV1_ROOT_PUBLIC_KEY, 0);
private static final Set<PublicKey> oemKeys = getOemPublicKey();
private static final Map<String, RootPublicKey.Status> pubkeys;

static {
ImmutableMap.Builder<String, Status> builder = ImmutableMap.builder();
getOemKeys()
.stream()
.map(k -> Base64.encodeToString(k.getEncoded(), Base64.NO_WRAP))
.forEach(s -> builder.put(s, Status.OEM));
pubkeys = builder
.put(GOOGLE_ROOT_PUBLIC_KEY, Status.GOOGLE)
.put(GOOGLE_RKP_ROOT_PUBLIC_KEY, Status.GOOGLE_RKP)
.put(AOSP_ROOT_EC_PUBLIC_KEY, Status.AOSP)
.put(AOSP_ROOT_RSA_PUBLIC_KEY, Status.AOSP)
.put(KNOX_SAKV1_ROOT_PUBLIC_KEY, Status.KNOX)
.put(KNOX_SAKV2_ROOT_PUBLIC_KEY, Status.KNOX)
.put(KNOX_SAKMV1_ROOT_PUBLIC_KEY, Status.KNOX)
.buildKeepingLast(); // keep our explicitly defined values over vendor-defined certs
}

private static Set<PublicKey> getOemPublicKey() {
private static Set<PublicKey> getOemKeys() {
var resName = "android:array/vendor_required_attestation_certificates";
var res = AppApplication.app.getResources();
// noinspection DiscouragedApi
var id = res.getIdentifier(resName, null, null);
var set = new HashSet<PublicKey>();
if (id == 0) {
return null;
return set;
}
var set = new HashSet<PublicKey>();
try {
var cf = CertificateFactory.getInstance("X.509");
for (var s : res.getStringArray(id)) {
Expand All @@ -96,36 +113,14 @@ private static Set<PublicKey> getOemPublicKey() {
}
} catch (CertificateException e) {
Log.e(AppApplication.TAG, "getOemKeys: ", e);
return null;
}
set.removeIf(key -> Arrays.equals(key.getEncoded(), googleKey));
if (set.isEmpty()) {
return null;
return Set.of();
}
set.forEach(key -> Log.i(AppApplication.TAG, "getOemKeys: " + key));
return set;
}

public static Status check(byte[] publicKey) {
if (Arrays.equals(publicKey, googleKey)) {
return Status.GOOGLE;
} else if (Arrays.equals(publicKey, aospEcKey)) {
return Status.AOSP;
} else if (Arrays.equals(publicKey, aospRsaKey)) {
return Status.AOSP;
} else if (Arrays.equals(publicKey, knoxSakv2Key)) {
return Status.KNOX;
} else if (Arrays.equals(publicKey, knoxSakv1Key)) {
return Status.KNOX;
} else if (Arrays.equals(publicKey, knoxSakmv1Key)) {
return Status.KNOX;
} else if (oemKeys != null) {
for (var key : oemKeys) {
if (Arrays.equals(publicKey, key.getEncoded())) {
return Status.OEM;
}
}
}
return Status.UNKNOWN;
String encodedPublicKey = Base64.encodeToString(publicKey, Base64.NO_WRAP);
return pubkeys.getOrDefault(encodedPublicKey, Status.UNKNOWN);
}
}