Added base64 encoded attachment support

lib/src/main/java/org/asamk/signal/manager/helper/AttachmentHelper.java

@@ -51,7 +51,7 @@ public class AttachmentHelper {
     }
 
     public SignalServiceAttachmentPointer uploadAttachment(String attachment) throws IOException, AttachmentInvalidException {
-        var attachmentStream = AttachmentUtils.createAttachmentStream(new File(attachment));
+        var attachmentStream = AttachmentUtils.createAttachmentStream(attachment);
         return uploadAttachment(attachmentStream);
     }
 

lib/src/main/java/org/asamk/signal/manager/util/AttachmentUtils.java

@@ -6,6 +6,7 @@ import org.whispersystems.signalservice.api.util.StreamDetails;
 import org.whispersystems.signalservice.internal.push.http.ResumableUploadSpec;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -19,17 +20,21 @@ public class AttachmentUtils {
         }
         final var signalServiceAttachments = new ArrayList<SignalServiceAttachmentStream>(attachments.size());
         for (var attachment : attachments) {
-            signalServiceAttachments.add(createAttachmentStream(new File(attachment)));
+            signalServiceAttachments.add(createAttachmentStream(attachment));
         }
         return signalServiceAttachments;
     }
 
-    public static SignalServiceAttachmentStream createAttachmentStream(File attachmentFile) throws AttachmentInvalidException {
+    public static SignalServiceAttachmentStream createAttachmentStream(String attachment) throws AttachmentInvalidException {
         try {
-            final var streamDetails = Utils.createStreamDetailsFromFile(attachmentFile);
-            return createAttachmentStream(streamDetails, Optional.of(attachmentFile.getName()));
+            final var streamDetails = Utils.createStreamDetails(attachment);
+            final var name = streamDetails.getStream() instanceof FileInputStream
+                    ? new File(attachment).getName()
+                    : null;
+
+            return createAttachmentStream(streamDetails, Optional.ofNullable(name));
         } catch (IOException e) {
-            throw new AttachmentInvalidException(attachmentFile.toString(), e);
+            throw new AttachmentInvalidException(attachment, e);
         }
     }
 

lib/src/main/java/org/asamk/signal/manager/util/Utils.java

@@ -9,6 +9,7 @@ import org.whispersystems.signalservice.api.push.SignalServiceAddress;
 import org.whispersystems.signalservice.api.util.StreamDetails;
 
 import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -17,6 +18,7 @@ import java.net.URLConnection;
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.util.Base64;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
@@ -44,6 +46,29 @@ public class Utils {
         return mime;
     }
 
+    private static boolean isBase64DataString(String[] parts) {
+        return parts.length == 2
+                && parts[0].startsWith("data:")
+                && parts[0].contains("/")
+                && parts[1].startsWith("base64,");
+    }
+
+    public static boolean isBase64DataString(String value) {
+        return isBase64DataString(value.split(";", 2));
+    }
+
+    public static StreamDetails createStreamDetailsFromBase64(String base64) {
+        final String[] parts = base64.split(";", 2);
+        if (!isBase64DataString(parts)) {
+            throw new IllegalArgumentException("The given argument is not a valid base64 string.");
+        }
+
+        parts[0] = parts[0].substring(5);
+        byte[] bytes = Base64.getDecoder().decode(parts[1].substring(7).getBytes(StandardCharsets.UTF_8));
+
+        return new StreamDetails(new ByteArrayInputStream(bytes), parts[0], bytes.length);
+    }
+
     public static StreamDetails createStreamDetailsFromFile(File file) throws IOException {
         InputStream stream = new FileInputStream(file);
         final var size = file.length();
@@ -51,6 +76,14 @@ public class Utils {
         return new StreamDetails(stream, mime, size);
     }
 
+    public static StreamDetails createStreamDetails(String value) throws IOException {
+        if (isBase64DataString(value)) {
+            return createStreamDetailsFromBase64(value);
+        }
+
+        return createStreamDetailsFromFile(new File(value));
+    }
+
     public static Fingerprint computeSafetyNumber(
             boolean isUuidCapable,
             SignalServiceAddress ownAddress,

src/main/java/org/asamk/signal/commands/SendCommand.java

@@ -55,7 +55,9 @@ public class SendCommand implements JsonRpcLocalCommand {
         mut.addArgument("--message-from-stdin")
                 .action(Arguments.storeTrue())
                 .help("Read the message from standard input.");
-        subparser.addArgument("-a", "--attachment").nargs("*").help("Add file as attachment");
+        subparser.addArgument("-a", "--attachment").nargs("*").help("Add file as attachment."
+                + "Base64 encoded attachments can be added and must follow the format "
+                + "data:<MIME-TYPE>;base64,<BASE64 ENCODED DATA>.");
         subparser.addArgument("-e", "--end-session", "--endsession")
                 .help("Clear session state and send end session message.")
                 .action(Arguments.storeTrue());