First implementation of encrypt command

pgpainless-sop/src/main/java/org/pgpainless/sop/PGPainlessCLI.java

@@ -17,6 +17,8 @@ package org.pgpainless.sop;
 
 import org.pgpainless.sop.commands.Armor;
 import org.pgpainless.sop.commands.Dearmor;
+import org.pgpainless.sop.commands.Decrypt;
+import org.pgpainless.sop.commands.Encrypt;
 import org.pgpainless.sop.commands.ExtractCert;
 import org.pgpainless.sop.commands.GenerateKey;
 import org.pgpainless.sop.commands.Sign;
@@ -26,13 +28,15 @@ import picocli.CommandLine;
 
 @CommandLine.Command(
         subcommands = {
-                Version.class,
-                GenerateKey.class,
+                Armor.class,
+                Dearmor.class,
+                Decrypt.class,
+                Encrypt.class,
                 ExtractCert.class,
+                GenerateKey.class,
                 Sign.class,
                 Verify.class,
-                Armor.class,
-                Dearmor.class
+                Version.class
         }
 )
 public class PGPainlessCLI implements Runnable {

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Decrypt.java

@@ -0,0 +1,12 @@
+package org.pgpainless.sop.commands;
+
+import picocli.CommandLine;
+
+@CommandLine.Command(name = "decrypt", description = "Decrypt a message")
+public class Decrypt implements Runnable {
+
+    @Override
+    public void run() {
+
+    }
+}

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Encrypt.java

@@ -0,0 +1,157 @@
+package org.pgpainless.sop.commands;
+
+import org.bouncycastle.bcpg.sig.KeyFlags;
+import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.openpgp.PGPPublicKeyRing;
+import org.bouncycastle.openpgp.PGPSecretKey;
+import org.bouncycastle.openpgp.PGPSecretKeyRing;
+import org.bouncycastle.openpgp.PGPSignature;
+import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
+import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
+import org.bouncycastle.util.io.Streams;
+import org.pgpainless.PGPainless;
+import org.pgpainless.algorithm.KeyFlag;
+import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
+import org.pgpainless.encryption_signing.EncryptionBuilderInterface;
+import org.pgpainless.encryption_signing.EncryptionStream;
+import org.pgpainless.key.OpenPgpV4Fingerprint;
+import org.pgpainless.key.protection.KeyRingProtectionSettings;
+import org.pgpainless.key.protection.PassphraseMapKeyRingProtector;
+import org.pgpainless.key.protection.SecretKeyRingProtector;
+import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
+import org.pgpainless.util.Passphrase;
+import picocli.CommandLine;
+
+import javax.annotation.Nullable;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+
+import static org.pgpainless.sop.Print.err_ln;
+import static org.pgpainless.sop.Print.print_ln;
+
+@CommandLine.Command(name = "encrypt", description = "Encrypt a message")
+public class Encrypt implements Runnable {
+
+    public enum Type {
+        binary,
+        text,
+        mime
+    }
+
+    @CommandLine.Option(names = "--no-armor",
+            description = "ASCII armor the output",
+            negatable = true)
+    boolean armor = true;
+
+    @CommandLine.Option(names = {"--as"},
+            description = "Type of the input data. Defaults to 'binary'",
+            paramLabel = "{binary|text|mime}")
+    Type type;
+
+    @CommandLine.Option(names = "--with-password",
+            description = "Encrypt the message with a password",
+            paramLabel = "PASSWORD")
+    String[] withPassword = new String[0];
+
+    @CommandLine.Option(names = "--sign-with",
+            description = "Sign the output with a private key",
+            paramLabel = "KEY")
+    File[] signWith = new File[0];
+
+    @CommandLine.Parameters(description = "Certificates the message gets encrypted to",
+            index = "0..*",
+            paramLabel = "CERTS")
+    File[] certs = new File[0];
+
+    @Override
+    public void run() {
+        if (certs.length == 0 && withPassword.length == 0) {
+            err_ln("Please either provide --with-password or at least one CERT");
+            System.exit(19);
+        }
+
+        PGPPublicKeyRing[] publicKeys = new PGPPublicKeyRing[certs.length];
+        for (int i = 0 ; i < certs.length; i++) {
+            try (InputStream fileIn = new FileInputStream(certs[i])) {
+                PGPPublicKeyRing publicKey = PGPainless.readKeyRing().publicKeyRing(fileIn);
+                publicKeys[i] = publicKey;
+            } catch (IOException e) {
+                err_ln("Cannot read certificate " + certs[i].getName());
+                err_ln(e.getMessage());
+                System.exit(1);
+            }
+        }
+        PGPSecretKeyRing[] secretKeys = new PGPSecretKeyRing[signWith.length];
+        for (int i = 0; i < signWith.length; i++) {
+            try(FileInputStream fileIn = new FileInputStream(signWith[i])) {
+                PGPSecretKeyRing secretKey = PGPainless.readKeyRing().secretKeyRing(fileIn);
+                secretKeys[i] = secretKey;
+            } catch (IOException | PGPException e) {
+                err_ln("Cannot read secret key from file " + signWith[i].getName());
+                err_ln(e.getMessage());
+                System.exit(1);
+            }
+        }
+
+        Map<Long, Passphrase> passphraseMap = new HashMap<>();
+        Scanner scanner = null;
+        for (PGPSecretKeyRing ring : secretKeys) {
+            for (PGPSecretKey key : ring) {
+                // Skip non-signing keys
+                PGPSignature signature = (PGPSignature) key.getPublicKey().getSignatures().next();
+                int flags = signature.getHashedSubPackets().getKeyFlags();
+                if (!key.isSigningKey() || !KeyFlag.hasKeyFlag(flags, KeyFlag.SIGN_DATA)) {
+                    // Key cannot sign
+                    continue;
+                }
+
+                if (key.getKeyEncryptionAlgorithm() == SymmetricKeyAlgorithm.NULL.getAlgorithmId()) {
+                    passphraseMap.put(key.getKeyID(), Passphrase.emptyPassphrase());
+                } else {
+                    print_ln("Please provide the passphrase for key " + new OpenPgpV4Fingerprint(key));
+                    if (scanner == null) {
+                        scanner = new Scanner(System.in);
+                    }
+                    String password = scanner.nextLine();
+                    Passphrase passphrase = Passphrase.fromPassword(password.trim());
+                    passphraseMap.put(key.getKeyID(), passphrase);
+                }
+            }
+        }
+
+        EncryptionBuilderInterface.DetachedSign builder = PGPainless.encryptAndOrSign()
+                .onOutputStream(System.out)
+                .toRecipients(publicKeys)
+                .usingSecureAlgorithms();
+        EncryptionBuilderInterface.Armor builder_armor;
+        if (signWith.length != 0) {
+            EncryptionBuilderInterface.DocumentType documentType = builder.signWith(new PassphraseMapKeyRingProtector(passphraseMap,
+                    KeyRingProtectionSettings.secureDefaultSettings(), null), secretKeys);
+            if (type == Type.text || type == Type.mime) {
+                builder_armor = documentType.signCanonicalText();
+            } else {
+                builder_armor = documentType.signBinaryDocument();
+            }
+        } else {
+            builder_armor = builder.doNotSign();
+        }
+        try {
+            EncryptionStream encryptionStream = !armor ? builder_armor.noArmor() : builder_armor.asciiArmor();
+
+            Streams.pipeAll(System.in, encryptionStream);
+
+            encryptionStream.close();
+        } catch (IOException | PGPException e) {
+            err_ln("An error happened.");
+            err_ln(e.getMessage());
+            System.exit(1);
+        }
+    }
+}