diff options
Diffstat (limited to 'OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp')
-rw-r--r-- | OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java | 164 |
1 files changed, 163 insertions, 1 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java index 2ee923e42..2ba0b6231 100644 --- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java +++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java @@ -22,6 +22,7 @@ import android.content.Context; import android.webkit.MimeTypeMap; import org.openintents.openpgp.OpenPgpMetadata; +import org.openintents.openpgp.OpenPgpSignatureResult; import org.spongycastle.bcpg.ArmoredInputStream; import org.spongycastle.openpgp.PGPCompressedData; import org.spongycastle.openpgp.PGPEncryptedData; @@ -46,6 +47,10 @@ import org.spongycastle.openpgp.operator.jcajce.NfcSyncPublicKeyDataDecryptorFac import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.R; import org.sufficientlysecure.keychain.operations.BaseOperation; +import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException; +import org.sufficientlysecure.keychain.pgp.exception.PgpKeyNotFoundException; +import org.sufficientlysecure.keychain.provider.KeychainContract.KeyRings; +import org.sufficientlysecure.keychain.provider.ProviderHelper; import org.sufficientlysecure.keychain.operations.results.DecryptVerifyResult; import org.sufficientlysecure.keychain.operations.results.OperationResult.LogType; import org.sufficientlysecure.keychain.operations.results.OperationResult.OperationLog; @@ -83,6 +88,8 @@ public class PgpDecryptVerify extends BaseOperation { private boolean mDecryptMetadataOnly; private byte[] mDecryptedSessionKey; private byte[] mDetachedSignature; + private String mRequiredSignerFingerprint; + private boolean mSignedLiteralData; protected PgpDecryptVerify(Builder builder) { super(builder.mContext, builder.mProviderHelper, builder.mProgressable); @@ -97,6 +104,8 @@ public class PgpDecryptVerify extends BaseOperation { this.mDecryptMetadataOnly = builder.mDecryptMetadataOnly; this.mDecryptedSessionKey = builder.mDecryptedSessionKey; this.mDetachedSignature = builder.mDetachedSignature; + this.mSignedLiteralData = builder.mSignedLiteralData; + this.mRequiredSignerFingerprint = builder.mRequiredSignerFingerprint; } public static class Builder { @@ -114,6 +123,8 @@ public class PgpDecryptVerify extends BaseOperation { private boolean mDecryptMetadataOnly = false; private byte[] mDecryptedSessionKey = null; private byte[] mDetachedSignature = null; + private String mRequiredSignerFingerprint = null; + private boolean mSignedLiteralData = false; public Builder(Context context, ProviderHelper providerHelper, Progressable progressable, @@ -125,6 +136,24 @@ public class PgpDecryptVerify extends BaseOperation { mOutStream = outStream; } + /** + * This is used when verifying signed literals to check that they are signed with + * the required key + */ + public Builder setRequiredSignerFingerprint(String fingerprint) { + mRequiredSignerFingerprint = fingerprint; + return this; + } + + /** + * This is to force a mode where the message is just the signature key id and + * then a literal data packet; used in Keybase.io proofs + */ + public Builder setSignedLiteralData(boolean signedLiteralData) { + mSignedLiteralData = signedLiteralData; + return this; + } + public Builder setAllowSymmetricDecryption(boolean allowSymmetricDecryption) { mAllowSymmetricDecryption = allowSymmetricDecryption; return this; @@ -189,7 +218,9 @@ public class PgpDecryptVerify extends BaseOperation { // it is ascii armored Log.d(Constants.TAG, "ASCII Armor Header Line: " + aIn.getArmorHeaderLine()); - if (aIn.isClearText()) { + if (mSignedLiteralData) { + return verifySignedLiteralData(aIn, 0); + } else if (aIn.isClearText()) { // a cleartext signature, verify it with the other method return verifyCleartextSignature(aIn, 0); } else { @@ -214,6 +245,136 @@ public class PgpDecryptVerify extends BaseOperation { } /** + * Verify Keybase.io style signed literal data + */ + private DecryptVerifyResult verifySignedLiteralData(InputStream in, int indent) throws IOException, PGPException { + OperationLog log = new OperationLog(); + log.add(LogType.MSG_VL, indent); + + // thinking that the proof-fetching operation is going to take most of the time + updateProgress(R.string.progress_reading_data, 75, 100); + + JcaPGPObjectFactory pgpF = new JcaPGPObjectFactory(in); + Object o = pgpF.nextObject(); + if (o instanceof PGPCompressedData) { + log.add(LogType.MSG_DC_CLEAR_DECOMPRESS, indent + 1); + + pgpF = new JcaPGPObjectFactory(((PGPCompressedData) o).getDataStream()); + o = pgpF.nextObject(); + updateProgress(R.string.progress_decompressing_data, 80, 100); + } + + // all we want to see is a OnePassSignatureList followed by LiteralData + if (!(o instanceof PGPOnePassSignatureList)) { + log.add(LogType.MSG_VL_ERROR_MISSING_SIGLIST, indent); + return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); + } + PGPOnePassSignatureList sigList = (PGPOnePassSignatureList) o; + + // go through all signatures (should be just one), make sure we have + // the key and it matches the one we’re looking for + CanonicalizedPublicKeyRing signingRing = null; + CanonicalizedPublicKey signingKey = null; + int signatureIndex = -1; + for (int i = 0; i < sigList.size(); ++i) { + try { + long sigKeyId = sigList.get(i).getKeyID(); + signingRing = mProviderHelper.getCanonicalizedPublicKeyRing( + KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(sigKeyId) + ); + signingKey = signingRing.getPublicKey(sigKeyId); + signatureIndex = i; + } catch (ProviderHelper.NotFoundException e) { + Log.d(Constants.TAG, "key not found, trying next signature..."); + } + } + + // there has to be a key, and it has to be the right one + if (signingKey == null) { + log.add(LogType.MSG_VL_ERROR_MISSING_KEY, indent); + Log.d(Constants.TAG, "Failed to find key in signed-literal message"); + return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); + } + + String fingerprint = KeyFormattingUtils.convertFingerprintToHex(signingRing.getFingerprint()); + if (!(mRequiredSignerFingerprint.equals(fingerprint))) { + log.add(LogType.MSG_VL_ERROR_MISSING_KEY, indent); + Log.d(Constants.TAG, "Fingerprint mismatch; wanted " + mRequiredSignerFingerprint + + " got " + fingerprint + "!"); + return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); + } + + OpenPgpSignatureResultBuilder signatureResultBuilder = new OpenPgpSignatureResultBuilder(); + + PGPOnePassSignature signature = sigList.get(signatureIndex); + signatureResultBuilder.initValid(signingRing, signingKey); + + JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider = + new JcaPGPContentVerifierBuilderProvider() + .setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME); + signature.init(contentVerifierBuilderProvider, signingKey.getPublicKey()); + + o = pgpF.nextObject(); + + if (!(o instanceof PGPLiteralData)) { + log.add(LogType.MSG_VL_ERROR_MISSING_LITERAL, indent); + return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); + } + + PGPLiteralData literalData = (PGPLiteralData) o; + + log.add(LogType.MSG_DC_CLEAR_DATA, indent + 1); + updateProgress(R.string.progress_decrypting, 85, 100); + + InputStream dataIn = literalData.getInputStream(); + + int length; + byte[] buffer = new byte[1 << 16]; + while ((length = dataIn.read(buffer)) > 0) { + mOutStream.write(buffer, 0, length); + signature.update(buffer, 0, length); + } + + updateProgress(R.string.progress_verifying_signature, 95, 100); + log.add(LogType.MSG_VL_CLEAR_SIGNATURE_CHECK, indent + 1); + + PGPSignatureList signatureList = (PGPSignatureList) pgpF.nextObject(); + PGPSignature messageSignature = signatureList.get(signatureIndex); + + // these are not cleartext signatures! + // TODO: what about binary signatures? + signatureResultBuilder.setSignatureOnly(false); + + // Verify signature and check binding signatures + boolean validSignature = signature.verify(messageSignature); + if (validSignature) { + log.add(LogType.MSG_DC_CLEAR_SIGNATURE_OK, indent + 1); + } else { + log.add(LogType.MSG_DC_CLEAR_SIGNATURE_BAD, indent + 1); + } + signatureResultBuilder.setValidSignature(validSignature); + + OpenPgpSignatureResult signatureResult = signatureResultBuilder.build(); + + if (signatureResult.getStatus() != OpenPgpSignatureResult.SIGNATURE_SUCCESS_CERTIFIED + && signatureResult.getStatus() != OpenPgpSignatureResult.SIGNATURE_SUCCESS_UNCERTIFIED) { + log.add(LogType.MSG_VL_ERROR_INTEGRITY_CHECK, indent); + return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); + } + + updateProgress(R.string.progress_done, 100, 100); + + log.add(LogType.MSG_VL_OK, indent); + + // Return a positive result, with metadata and verification info + DecryptVerifyResult result = + new DecryptVerifyResult(DecryptVerifyResult.RESULT_OK, log); + result.setSignatureResult(signatureResult); + return result; + } + + + /** * Decrypt and/or verifies binary or ascii armored pgp */ private DecryptVerifyResult decryptVerify(InputStream in, int indent) throws IOException, PGPException { @@ -672,6 +833,7 @@ public class PgpDecryptVerify extends BaseOperation { // If no valid signature is present: // Handle missing integrity protection like failed integrity protection! // The MDC packet can be stripped by an attacker! + Log.d(Constants.TAG, "MDC fail"); if (!signatureResultBuilder.isValidSignature()) { log.add(LogType.MSG_DC_ERROR_INTEGRITY_MISSING, indent); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); 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