Convert to and from UTF-8 without catching impossible exceptions.

All JVMs must support UTF-8 encoding.

briar-api/src/org/briarproject/api/Author.java

@@ -2,7 +2,7 @@ package org.briarproject.api;
 
 import static org.briarproject.api.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 
-import java.io.UnsupportedEncodingException;
+import java.nio.charset.Charset;
 
 /** A pseudonym for a user. */
 public class Author {
@@ -14,13 +14,9 @@ public class Author {
 	private final byte[] publicKey;
 
 	public Author(AuthorId id, String name, byte[] publicKey) {
-		if(name.length() == 0) throw new IllegalArgumentException();
+		int length = name.getBytes(Charset.forName("UTF-8")).length;
-		try {
+		if(length == 0 || length > MAX_AUTHOR_NAME_LENGTH)
-			if(name.getBytes("UTF-8").length > MAX_AUTHOR_NAME_LENGTH)
+			throw new IllegalArgumentException();
-				throw new IllegalArgumentException();
-		} catch(UnsupportedEncodingException e) {
-			throw new RuntimeException(e);
-		}
 		this.id = id;
 		this.name = name;
 		this.publicKey = publicKey;

briar-api/src/org/briarproject/api/messaging/Group.java

@@ -3,7 +3,7 @@ package org.briarproject.api.messaging;
 import static org.briarproject.api.messaging.MessagingConstants.GROUP_SALT_LENGTH;
 import static org.briarproject.api.messaging.MessagingConstants.MAX_GROUP_NAME_LENGTH;
 
-import java.io.UnsupportedEncodingException;
+import java.nio.charset.Charset;
 
 /** A group to which users may subscribe. */
 public class Group {
@@ -13,13 +13,9 @@ public class Group {
 	private final byte[] salt;
 
 	public Group(GroupId id, String name, byte[] salt) {
-		if(name.length() == 0) throw new IllegalArgumentException();
+		int length = name.getBytes(Charset.forName("UTF-8")).length;
-		try {
+		if(length == 0 || length > MAX_GROUP_NAME_LENGTH)
-			if(name.getBytes("UTF-8").length > MAX_GROUP_NAME_LENGTH)
+			throw new IllegalArgumentException();
-				throw new IllegalArgumentException();
-		} catch(UnsupportedEncodingException e) {
-			throw new RuntimeException(e);
-		}
 		if(salt.length != GROUP_SALT_LENGTH)
 			throw new IllegalArgumentException();
 		this.id = id;

briar-core/src/org/briarproject/messaging/MessageFactoryImpl.java

@@ -31,6 +31,7 @@ import org.briarproject.api.serial.DigestingConsumer;
 import org.briarproject.api.serial.SigningConsumer;
 import org.briarproject.api.serial.Writer;
 import org.briarproject.api.serial.WriterFactory;
+import org.briarproject.util.StringUtils;
 
 class MessageFactoryImpl implements MessageFactory {
 
@@ -68,7 +69,7 @@ class MessageFactoryImpl implements MessageFactory {
 		// Validate the arguments
 		if((author == null) != (privateKey == null))
 			throw new IllegalArgumentException();
-		if(contentType.getBytes("UTF-8").length > MAX_CONTENT_TYPE_LENGTH)
+		if(StringUtils.toUtf8(contentType).length > MAX_CONTENT_TYPE_LENGTH)
 			throw new IllegalArgumentException();
 		if(body.length > MAX_BODY_LENGTH)
 			throw new IllegalArgumentException();

briar-core/src/org/briarproject/serial/ReaderImpl.java

@@ -21,6 +21,7 @@ import static org.briarproject.serial.Tag.TRUE;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collection;
 
@@ -234,7 +235,7 @@ class ReaderImpl implements Reader {
 		if(length < 0 || length > maxLength) throw new FormatException();
 		if(length == 0) return "";
 		readIntoBuffer(length, true);
-		return new String(buf, 0, length, "UTF-8");
+		return new String(buf, 0, length, Charset.forName("UTF-8"));
 	}
 
 	private int readStringLength(boolean consume) throws IOException {

briar-core/src/org/briarproject/serial/WriterImpl.java

@@ -16,6 +16,7 @@ import static org.briarproject.serial.Tag.TRUE;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -102,7 +103,7 @@ class WriterImpl implements Writer {
 	}
 
 	public void writeString(String s) throws IOException {
-		byte[] b = s.getBytes("UTF-8");
+		byte[] b = s.getBytes(Charset.forName("UTF-8"));
 		if(b.length <= Byte.MAX_VALUE) {
 			write(STRING_8);
 			write((byte) b.length);

briar-desktop/src/org/briarproject/plugins/modem/ModemImpl.java

@@ -307,6 +307,7 @@ class ModemImpl implements Modem, WriteHandler, SerialPortEventListener {
 		for(int i = 0; i < b.length; i++) {
 			line[lineLen] = b[i];
 			if(b[i] == '\n') {
+				// FIXME: Use CharsetDecoder to catch invalid ASCII
 				String s = new String(line, 0, lineLen, "US-ASCII").trim();
 				lineLen = 0;
 				if(LOG.isLoggable(INFO)) LOG.info("Modem status: " + s);