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Code Issues Releases Wiki Activity

DKIM Ed25519 via Android encryption

This commit is contained in:
M66B 2023-08-03 08:12:09 +02:00
parent 617d0315bd
commit 32c7e06781
1 changed files with 27 additions and 11 deletions
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38
app/src/main/java/eu/faircode/email/MessageHelper.java
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@ -66,6 +66,9 @@ import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;
import org.apache.commons.compress.archivers.zip.UnsupportedZipFeatureException;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
import org.bouncycastle.asn1.edec.EdECObjectIdentifiers;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.json.JSONObject;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
@ -2453,10 +2456,30 @@ public class MessageHelper {
String p = pubkey.replaceAll("\\s+", "");
Log.i("DKIM pubkey=" + p);
X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(Base64.decode(p, Base64.DEFAULT));
String hash = kv.get("b");
if (hash == null)
return null;
String s = hash.replaceAll("\\s+", "");
Log.i("DKIM signature=" + s);
byte[] data = head.toString().getBytes();
byte[] key = Base64.decode(p, Base64.DEFAULT);
byte[] signature = Base64.decode(s, Base64.DEFAULT);
if ("Ed25519".equals(salgo)) {
if (false) {
// https://www.rfc-editor.org/rfc/rfc8037#page-9
data = "eyJhbGciOiJFZERTQSJ9.RXhhbXBsZSBvZiBFZDI1NTE5IHNpZ25pbmc".getBytes(StandardCharsets.UTF_8);
key = Base64.decode("11qYAYKxCrfVS_7TyWQHOg7hcvPapiMlrwIaaPcHURo", Base64.URL_SAFE);
signature = Base64.decode("hgyY0il_MGCjP0JzlnLWG1PPOt7-09PGcvMg3AIbQR6dWbhijcNR4ki4iylGjg5BhVsPt9g7sVvpAr_MuM0KAg", Base64.URL_SAFE);
}
key = new SubjectPublicKeyInfo(new AlgorithmIdentifier(EdECObjectIdentifiers.id_Ed25519), key).getEncoded();
}
X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(key);
KeyFactory keyFactory = KeyFactory.getInstance("Ed25519".equals(salgo) ? "Ed25519" : "RSA");
PublicKey pubKey = keyFactory.generatePublic(pubKeySpec);
Signature sig = Signature.getInstance(salgo); // a=
Signature sig = Signature.getInstance("Ed25519".equals(salgo) ? "EdDSA" : salgo); // a=
// https://stackoverflow.com/a/43984402/1794097
if (pubKey instanceof RSAPublicKey)
@ -2469,19 +2492,12 @@ public class MessageHelper {
Log.e(ex);
}
String hash = kv.get("b");
if (hash == null)
return null;
String s = hash.replaceAll("\\s+", "");
Log.i("DKIM signature=" + s);
byte[] signature = Base64.decode(s, Base64.DEFAULT);
sig.initVerify(pubKey);
sig.update(head.toString().getBytes());
sig.update(data);
boolean verified = sig.verify(signature);
Log.i("DKIM valid=" + verified +
" algo=" + salgo +
" dns=" + dns +
" from=" + formatAddresses(getFrom()));