sop-java/sop-java-picocli/src/main/java/sop/cli/picocli/commands/DecryptCmd.java
2022-05-29 21:17:03 +02:00

261 lines
11 KiB
Java

// SPDX-FileCopyrightText: 2020 Paul Schaub <vanitasvitae@fsfe.org>
//
// SPDX-License-Identifier: Apache-2.0
package sop.cli.picocli.commands;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.regex.Pattern;
import picocli.CommandLine;
import sop.DecryptionResult;
import sop.ReadyWithResult;
import sop.SessionKey;
import sop.Verification;
import sop.cli.picocli.DateParser;
import sop.cli.picocli.FileUtil;
import sop.cli.picocli.SopCLI;
import sop.exception.SOPGPException;
import sop.operation.Decrypt;
import sop.util.HexUtil;
@CommandLine.Command(name = "decrypt",
description = "Decrypt a message from standard input",
exitCodeOnInvalidInput = SOPGPException.UnsupportedOption.EXIT_CODE)
public class DecryptCmd extends AbstractSopCmd {
private static final String OPT_WITH_SESSION_KEY = "--with-session-key";
private static final String OPT_WITH_PASSWORD = "--with-password";
private static final String OPT_NOT_BEFORE = "--not-before";
private static final String OPT_NOT_AFTER = "--not-after";
private static final String OPT_SESSION_KEY_OUT = "--session-key-out";
private static final String OPT_VERIFY_OUT = "--verify-out";
private static final String OPT_VERIFY_WITH = "--verify-with";
private static final String OPT_WITH_KEY_PASSWORD = "--with-key-password";
@CommandLine.Option(
names = {OPT_SESSION_KEY_OUT},
description = "Can be used to learn the session key on successful decryption",
paramLabel = "SESSIONKEY")
File sessionKeyOut;
@CommandLine.Option(
names = {OPT_WITH_SESSION_KEY},
description = "Provide a session key file. Enables decryption of the \"CIPHERTEXT\" using the session key directly against the \"SEIPD\" packet",
paramLabel = "SESSIONKEY")
List<String> withSessionKey = new ArrayList<>();
@CommandLine.Option(
names = {OPT_WITH_PASSWORD},
description = "Provide a password file. Enables decryption based on any \"SKESK\" packets in the \"CIPHERTEXT\"",
paramLabel = "PASSWORD")
List<String> withPassword = new ArrayList<>();
@CommandLine.Option(names = {OPT_VERIFY_OUT},
description = "Produces signature verification status to the designated file",
paramLabel = "VERIFICATIONS")
File verifyOut;
@CommandLine.Option(names = {OPT_VERIFY_WITH},
description = "Certificates whose signatures would be acceptable for signatures over this message",
paramLabel = "CERT")
List<File> certs = new ArrayList<>();
@CommandLine.Option(names = {OPT_NOT_BEFORE},
description = "ISO-8601 formatted UTC date (eg. '2020-11-23T16:35Z)\n" +
"Reject signatures with a creation date not in range.\n" +
"Defaults to beginning of time (\"-\").",
paramLabel = "DATE")
String notBefore = "-";
@CommandLine.Option(names = {OPT_NOT_AFTER},
description = "ISO-8601 formatted UTC date (eg. '2020-11-23T16:35Z)\n" +
"Reject signatures with a creation date not in range.\n" +
"Defaults to current system time (\"now\").\n" +
"Accepts special value \"-\" for end of time.",
paramLabel = "DATE")
String notAfter = "now";
@CommandLine.Parameters(index = "0..*",
description = "Secret keys to attempt decryption with",
paramLabel = "KEY")
List<File> keys = new ArrayList<>();
@CommandLine.Option(names = {OPT_WITH_KEY_PASSWORD},
description = "Provide indirect file type pointing at passphrase(s) for secret key(s)",
paramLabel = "PASSWORD")
List<String> withKeyPassword = new ArrayList<>();
@Override
public void run() {
Decrypt decrypt = throwIfUnsupportedSubcommand(
SopCLI.getSop().decrypt(), "decrypt");
throwIfOutputExists(verifyOut, OPT_VERIFY_OUT);
throwIfOutputExists(sessionKeyOut, OPT_SESSION_KEY_OUT);
setNotAfter(notAfter, decrypt);
setNotBefore(notBefore, decrypt);
setWithPasswords(withPassword, decrypt);
setWithSessionKeys(withSessionKey, decrypt);
setWithKeyPassword(withKeyPassword, decrypt);
setVerifyWith(certs, decrypt);
setDecryptWith(keys, decrypt);
if (verifyOut != null && certs.isEmpty()) {
String errorMessage = "Option %s is requested, but no option %s was provided.";
throw new SOPGPException.IncompleteVerification(String.format(errorMessage, OPT_VERIFY_OUT, OPT_VERIFY_WITH));
}
try {
ReadyWithResult<DecryptionResult> ready = decrypt.ciphertext(System.in);
DecryptionResult result = ready.writeTo(System.out);
writeSessionKeyOut(result);
writeVerifyOut(result);
} catch (SOPGPException.BadData badData) {
throw new SOPGPException.BadData("No valid OpenPGP message found on Standard Input.", badData);
} catch (IOException ioException) {
throw new RuntimeException(ioException);
}
}
private void writeVerifyOut(DecryptionResult result) throws IOException {
if (verifyOut != null) {
FileUtil.createNewFileOrThrow(verifyOut);
try (FileOutputStream outputStream = new FileOutputStream(verifyOut)) {
PrintWriter writer = new PrintWriter(outputStream);
for (Verification verification : result.getVerifications()) {
// CHECKSTYLE:OFF
writer.println(verification.toString());
// CHECKSTYLE:ON
}
writer.flush();
}
}
}
private void writeSessionKeyOut(DecryptionResult result) throws IOException {
if (sessionKeyOut != null) {
FileUtil.createNewFileOrThrow(sessionKeyOut);
try (FileOutputStream outputStream = new FileOutputStream(sessionKeyOut)) {
if (!result.getSessionKey().isPresent()) {
String errorMsg = "Session key not extracted. Possibly the feature %s is not supported.";
throw new SOPGPException.UnsupportedOption(String.format(errorMsg, OPT_SESSION_KEY_OUT));
} else {
SessionKey sessionKey = result.getSessionKey().get();
outputStream.write(sessionKey.getAlgorithm());
outputStream.write(sessionKey.getKey());
}
}
}
}
private void setDecryptWith(List<File> keys, Decrypt decrypt) {
for (File key : keys) {
try (FileInputStream keyIn = new FileInputStream(key)) {
decrypt.withKey(keyIn);
} catch (SOPGPException.KeyIsProtected keyIsProtected) {
throw new SOPGPException.KeyIsProtected("Key in file " + key.getAbsolutePath() + " is password protected.", keyIsProtected);
} catch (SOPGPException.BadData badData) {
throw new SOPGPException.BadData("File " + key.getAbsolutePath() + " does not contain a private key.", badData);
} catch (FileNotFoundException e) {
throw new SOPGPException.MissingInput(String.format(ERROR_FILE_NOT_EXIST, key.getAbsolutePath()), e);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
private void setVerifyWith(List<File> certs, Decrypt decrypt) {
for (File cert : certs) {
try (FileInputStream certIn = new FileInputStream(cert)) {
decrypt.verifyWithCert(certIn);
} catch (FileNotFoundException e) {
throw new SOPGPException.MissingInput(String.format(ERROR_FILE_NOT_EXIST, cert.getAbsolutePath()), e);
} catch (SOPGPException.BadData badData) {
throw new SOPGPException.BadData("File " + cert.getAbsolutePath() + " does not contain a valid certificate.", badData);
} catch (IOException ioException) {
throw new RuntimeException(ioException);
}
}
}
private void setWithSessionKeys(List<String> withSessionKey, Decrypt decrypt) {
Pattern sessionKeyPattern = Pattern.compile("^\\d+:[0-9A-F]+$");
for (String sessionKeyFile : withSessionKey) {
String sessionKey;
try {
sessionKey = FileUtil.stringFromInputStream(FileUtil.getFileInputStream(sessionKeyFile));
} catch (IOException e) {
throw new RuntimeException(e);
}
if (!sessionKeyPattern.matcher(sessionKey).matches()) {
throw new IllegalArgumentException("Session keys are expected in the format 'ALGONUM:HEXKEY'.");
}
String[] split = sessionKey.split(":");
byte algorithm = (byte) Integer.parseInt(split[0]);
byte[] key = HexUtil.hexToBytes(split[1]);
try {
decrypt.withSessionKey(new SessionKey(algorithm, key));
} catch (SOPGPException.UnsupportedOption unsupportedOption) {
throw new SOPGPException.UnsupportedOption(String.format(ERROR_UNSUPPORTED_OPTION, OPT_WITH_SESSION_KEY), unsupportedOption);
}
}
}
private void setWithPasswords(List<String> withPassword, Decrypt decrypt) {
for (String passwordFile : withPassword) {
try {
String password = FileUtil.stringFromInputStream(FileUtil.getFileInputStream(passwordFile));
decrypt.withPassword(password);
} catch (SOPGPException.UnsupportedOption unsupportedOption) {
throw new SOPGPException.UnsupportedOption(String.format(ERROR_UNSUPPORTED_OPTION, OPT_WITH_PASSWORD), unsupportedOption);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
private void setWithKeyPassword(List<String> withKeyPassword, Decrypt decrypt) {
for (String passwordFile : withKeyPassword) {
try {
String password = FileUtil.stringFromInputStream(FileUtil.getFileInputStream(passwordFile));
decrypt.withKeyPassword(password);
} catch (SOPGPException.UnsupportedOption unsupportedOption) {
throw new SOPGPException.UnsupportedOption(String.format(ERROR_UNSUPPORTED_OPTION, OPT_WITH_KEY_PASSWORD), unsupportedOption);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
private void setNotAfter(String notAfter, Decrypt decrypt) {
Date notAfterDate = DateParser.parseNotAfter(notAfter);
try {
decrypt.verifyNotAfter(notAfterDate);
} catch (SOPGPException.UnsupportedOption unsupportedOption) {
throw new SOPGPException.UnsupportedOption(String.format(ERROR_UNSUPPORTED_OPTION, OPT_NOT_AFTER), unsupportedOption);
}
}
private void setNotBefore(String notBefore, Decrypt decrypt) {
Date notBeforeDate = DateParser.parseNotBefore(notBefore);
try {
decrypt.verifyNotBefore(notBeforeDate);
} catch (SOPGPException.UnsupportedOption unsupportedOption) {
throw new SOPGPException.UnsupportedOption(String.format(ERROR_UNSUPPORTED_OPTION, OPT_NOT_BEFORE), unsupportedOption);
}
}
}