Add implementation of update-key command

sop-java-picocli/src/main/kotlin/sop/cli/picocli/SopCLI.kt

@@ -27,6 +27,7 @@ import sop.exception.SOPGPException
             ChangeKeyPasswordCmd::class,
             RevokeKeyCmd::class,
             ExtractCertCmd::class,
+            UpdateKeyCmd::class,
             // Messaging subcommands
             SignCmd::class,
             VerifyCmd::class,

sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/UpdateKeyCmd.kt

@@ -0,0 +1,76 @@
+// SPDX-FileCopyrightText: 2024 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.cli.picocli.commands
+
+import picocli.CommandLine.Command
+import picocli.CommandLine.Option
+import sop.cli.picocli.SopCLI
+import sop.exception.SOPGPException.*
+import java.io.IOException
+
+@Command(
+    name = "update-key",
+    resourceBundle = "msg_update-key",
+    exitCodeOnInvalidInput = UnsupportedOption.EXIT_CODE)
+class UpdateKeyCmd : AbstractSopCmd() {
+
+    @Option(names = ["--no-armor"], negatable = true) var armor = true
+
+    @Option(names = ["--signing-only"]) var signingOnly = false
+
+    @Option(names = ["--no-new-mechanisms"]) var noNewMechanisms = false
+
+    @Option(names = ["--with-key-password"], paramLabel = "PASSWORD")
+    var withKeyPassword: List<String> = listOf()
+
+    @Option(names = ["--merge-certs"], paramLabel = "CERTS")
+    var mergeCerts: List<String> = listOf()
+
+    override fun run() {
+        val updateKey = throwIfUnsupportedSubcommand(SopCLI.getSop().updateKey(), "update-key")
+
+        if (!armor) {
+            updateKey.noArmor()
+        }
+
+        if (signingOnly) {
+            updateKey.signingOnly()
+        }
+
+        if (noNewMechanisms) {
+            updateKey.noNewMechanisms()
+        }
+
+        for (passwordFileName in withKeyPassword) {
+            try {
+                val password = stringFromInputStream(getInput(passwordFileName))
+                updateKey.withKeyPassword(password)
+            } catch (unsupportedOption: UnsupportedOption) {
+                val errorMsg = getMsg("sop.error.feature_support.option_not_supported", "--with-key-password")
+                throw UnsupportedOption(errorMsg, unsupportedOption)
+            } catch (e: IOException) {
+                throw RuntimeException(e)
+            }
+        }
+
+        for (certInput in mergeCerts) {
+            try {
+                getInput(certInput).use { certIn -> updateKey.mergeCerts(certIn) }
+            } catch (e: IOException) {
+                throw RuntimeException(e)
+            } catch (badData: BadData) {
+                val errorMsg = getMsg("sop.error.input.not_a_certificate", certInput)
+                throw BadData(errorMsg, badData)
+            }
+        }
+
+        try {
+            val ready = updateKey.key(System.`in`)
+            ready.writeTo(System.out)
+        } catch (e: IOException) {
+            throw RuntimeException(e)
+        }
+    }
+}