Fixes #1922: add command to convert private jwk to public jwk (#1945)

* Fixes #1922: add command to convert private jwk to public jwk

* Update core/src/main/java/com/predic8/membrane/core/cli/RouterCLI.java

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

---------

Co-authored-by: Thomas Bayer <bayer@predic8.de>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: t-burch <119930761+t-burch@users.noreply.github.com>

Author: 4 people

core/src/main/java/com/predic8/membrane/core/cli/MembraneCommandLine.java

@@ -68,6 +68,11 @@ private static Options getRootOptions() {
                 addOption(builder("overwrite").desc("Overwrite the output file, if it exists.").build());
             }});
 
+            addSubcommand(new CliCommand("private-jwk-to-public", "Convert a private JWK to a public JWK.") {{
+                addOption(builder("i").longOpt("input").argName("file").hasArg().desc("Input file (JWK, private).").build());
+                addOption(builder("o").longOpt("output").argName("file").hasArg().desc("Output file (JWK, public).").build());
+            }});
+
         }};
     }
 

core/src/main/java/com/predic8/membrane/core/cli/RouterCLI.java

@@ -83,6 +83,19 @@ public static void main(String[] args) {
             System.exit(0);
         }
 
+        if (commandLine.getCommand().getName().equals("private-jwk-to-public")) {
+            String input = commandLine.getCommand().getOptionValue("i");
+            String output = commandLine.getCommand().getOptionValue("o");
+            if (input == null || output == null) {
+                log.error("Both input (-i) and output (-o) files must be specified.");
+                System.exit(1);
+            }
+            privateJWKtoPublic(
+                    input,
+                    output);
+            System.exit(0);
+        }
+
         try {
             getRouter(commandLine).waitFor();
         } catch (InterruptedException e) {
@@ -190,6 +203,17 @@ private static void generateJWK(MembraneCommandLine commandLine) {
         }
     }
 
+    private static void privateJWKtoPublic(String input, String output) {
+        try {
+            Map map = new ObjectMapper().readValue(new File(input), Map.class);
+            RsaJsonWebKey rsa = new RsaJsonWebKey(map);
+            Files.writeString(Paths.get(output), rsa.toJson(JsonWebKey.OutputControlLevel.PUBLIC_ONLY));
+        } catch (IOException | JoseException e) {
+            log.error(e.getMessage());
+            System.exit(1);
+        }
+    }
+
     private static @NotNull APIProxy getApiProxy(MembraneCommandLine commandLine) {
         APIProxy api = new APIProxy();
         api.setPort(commandLine.getCommand().isOptionSet("p") ?