Read support for 12-byte IVs in addition to 16-byte IVs

This commit is contained in:
moparisthebest 2017-08-09 23:42:35 -04:00
parent d8d1c1192f
commit 197352b669
5 changed files with 17 additions and 4 deletions

View File

@ -49,11 +49,18 @@ public class DownloadableFile extends File {
}
public void setKeyAndIv(byte[] keyIvCombo) {
// originally, we used a 16 byte IV, then found for aes-gcm a 12 byte IV is ideal
// this code supports reading either length, with sending 12 byte IV to be done in future
if (keyIvCombo.length == 48) {
this.aeskey = new byte[32];
this.iv = new byte[16];
System.arraycopy(keyIvCombo, 0, this.iv, 0, 16);
System.arraycopy(keyIvCombo, 16, this.aeskey, 0, 32);
} else if (keyIvCombo.length == 44) {
this.aeskey = new byte[32];
this.iv = new byte[12];
System.arraycopy(keyIvCombo, 0, this.iv, 0, 12);
System.arraycopy(keyIvCombo, 12, this.aeskey, 0, 32);
} else if (keyIvCombo.length >= 32) {
this.aeskey = new byte[32];
System.arraycopy(keyIvCombo, 0, aeskey, 0, 32);

View File

@ -670,7 +670,7 @@ public class Message extends AbstractEntity {
final URL url = new URL(body);
final String ref = url.getRef();
final String protocol = url.getProtocol();
final boolean encrypted = ref != null && ref.matches("([A-Fa-f0-9]{2}){48}");
final boolean encrypted = ref != null && AesGcmURLStreamHandler.IV_KEY.matcher(ref).matches();
treatAsDownloadable = (AesGcmURLStreamHandler.PROTOCOL_NAME.equalsIgnoreCase(protocol) && encrypted)
|| (("http".equalsIgnoreCase(protocol) || "https".equalsIgnoreCase(protocol)) && (oob || encrypted));

View File

@ -4,10 +4,16 @@ import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.util.regex.Pattern;
public class AesGcmURLStreamHandler extends URLStreamHandler {
/**
* This matches a 48 or 44 byte IV + KEY hex combo, like used in http/aesgcm upload anchors
*/
public static final Pattern IV_KEY = Pattern.compile("([A-Fa-f0-9]{2}){48}|([A-Fa-f0-9]{2}){44}");
public static final String PROTOCOL_NAME = "aesgcm";
@Override

View File

@ -92,7 +92,7 @@ public class HttpDownloadConnection implements Transferable {
message.setRelativeFilePath(message.getUuid() + "." + extension);
this.file = mXmppConnectionService.getFileBackend().getFile(message, false);
final String reference = mUrl.getRef();
if (reference != null && reference.matches("([A-Fa-f0-9]{2}){48}")) {
if (reference != null && AesGcmURLStreamHandler.IV_KEY.matcher(reference).matches()) {
this.file.setKeyAndIv(CryptoHelper.hexToBytes(reference));
}
@ -373,7 +373,7 @@ public class HttpDownloadConnection implements Transferable {
message.setType(Message.TYPE_FILE);
final URL url;
final String ref = mUrl.getRef();
if (ref != null && ref.matches("([A-Fa-f0-9]{2}){48}")) {
if (ref != null && AesGcmURLStreamHandler.IV_KEY.matcher(ref).matches()) {
url = CryptoHelper.toAesGcmUrl(mUrl);
} else {
url = mUrl;

View File

@ -105,7 +105,7 @@ public class HttpUploadConnection implements Transferable {
if (Config.ENCRYPT_ON_HTTP_UPLOADED
|| message.getEncryption() == Message.ENCRYPTION_AXOLOTL
|| message.getEncryption() == Message.ENCRYPTION_OTR) {
this.key = new byte[48];
this.key = new byte[48]; // todo: change this to 44 for 12-byte IV instead of 16-byte at some point in future
mXmppConnectionService.getRNG().nextBytes(this.key);
this.file.setKeyAndIv(this.key);
}