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pgpdecryptverify: refactor signature verification state into SignatureChecker subclass

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This commit is contained in:
Vincent Breitmoser
2015-10-08 13:53:58 +02:00
parent f6de2712d3
commit fe8db664a8
2 changed files with 142 additions and 136 deletions
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277
OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerifyOperation.java
View File

@@ -207,22 +207,18 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
updateProgress(R.string.progress_decompressing_data, 80, 100);
}
// all we want to see is a OnePassSignatureList followed by LiteralData
if (!(o instanceof PGPOnePassSignatureList)) {
SignatureChecker signatureChecker = new SignatureChecker();
if ( ! signatureChecker.initializeOnePassSignature(o, log, indent)) {
log.add(LogType.MSG_VL_ERROR_MISSING_SIGLIST, indent);
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
PGPOnePassSignatureList sigList = (PGPOnePassSignatureList) o;
SignatureData signatureData = findAvailableSignature(sigList);
if (signatureData == null) {
if ( ! signatureChecker.isInitialized()) {
log.add(LogType.MSG_VL_ERROR_MISSING_KEY, indent);
Log.d(Constants.TAG, "Failed to find signature with available key in signed-literal message");
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
String fingerprint = KeyFormattingUtils.convertFingerprintToHex(signatureData.signingKey.getFingerprint());
String fingerprint = KeyFormattingUtils.convertFingerprintToHex(signatureChecker.getSigningFingerprint());
if (!(input.getRequiredSignerFingerprint().equals(fingerprint))) {
log.add(LogType.MSG_VL_ERROR_MISSING_KEY, indent);
Log.d(Constants.TAG, "Fingerprint mismatch; wanted " + input.getRequiredSignerFingerprint() +
@@ -230,16 +226,6 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
OpenPgpSignatureResultBuilder signatureResultBuilder = new OpenPgpSignatureResultBuilder();
PGPOnePassSignature signature = sigList.get(signatureData.signatureIndex);
signatureResultBuilder.initValid(signatureData.signingKey);
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
signature.init(contentVerifierBuilderProvider, signatureData.signingKey.getPublicKey());
o = pgpF.nextObject();
if (!(o instanceof PGPLiteralData)) {
@@ -258,38 +244,18 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
byte[] buffer = new byte[1 << 16];
while ((length = dataIn.read(buffer)) > 0) {
out.write(buffer, 0, length);
signature.update(buffer, 0, length);
signatureChecker.updateSignatureData(buffer, 0, length);
}
updateProgress(R.string.progress_verifying_signature, 95, 100);
log.add(LogType.MSG_VL_CLEAR_SIGNATURE_CHECK, indent + 1);
o = pgpF.nextObject();
if ( ! (o instanceof PGPSignatureList) ) {
log.add(LogType.MSG_VL_ERROR_NO_SIGNATURE, indent);
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
PGPSignatureList signatureList = (PGPSignatureList) o;
if (signatureList.size() <= signatureData.signatureIndex) {
log.add(LogType.MSG_VL_ERROR_NO_SIGNATURE, indent);
if ( ! signatureChecker.verifySignature(o, log, indent) ) {
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
// PGPOnePassSignature and PGPSignature packets are "bracketed",
// so we need to take the last-minus-index'th element here
PGPSignature messageSignature = signatureList.get(signatureList.size() -1 -signatureData.signatureIndex);
// 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();
OpenPgpSignatureResult signatureResult = signatureChecker.getSignatureResult();
if (signatureResult.getResult() != OpenPgpSignatureResult.RESULT_VALID_CONFIRMED
&& signatureResult.getResult() != OpenPgpSignatureResult.RESULT_VALID_UNCONFIRMED) {
@@ -364,7 +330,6 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
}
}
OpenPgpSignatureResultBuilder signatureResultBuilder = new OpenPgpSignatureResultBuilder();
OpenPgpDecryptionResultBuilder decryptionResultBuilder = new OpenPgpDecryptionResultBuilder();
JcaPGPObjectFactory plainFact;
@@ -411,8 +376,6 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
log.add(LogType.MSG_DC_PREP_STREAMS, indent);
SignatureData signatureData = null;
log.add(LogType.MSG_DC_CLEAR, indent);
indent += 1;
@@ -429,41 +392,8 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
plainFact = fact;
}
// resolve leading signature data
PGPOnePassSignature signature = null;
if (dataChunk instanceof PGPOnePassSignatureList) {
log.add(LogType.MSG_DC_CLEAR_SIGNATURE, indent + 1);
currentProgress += 2;
updateProgress(R.string.progress_processing_signature, currentProgress, 100);
PGPOnePassSignatureList sigList = (PGPOnePassSignatureList) dataChunk;
signatureData = findAvailableSignature(sigList);
if (signatureData != null) {
// key found in our database!
signature = sigList.get(signatureData.signatureIndex);
signatureResultBuilder.initValid(signatureData.signingKey);
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
signature.init(contentVerifierBuilderProvider, signatureData.signingKey.getPublicKey());
} else {
// no key in our database -> return "unknown pub key" status including the first key id
if (!sigList.isEmpty()) {
signatureResultBuilder.setSignatureAvailable(true);
signatureResultBuilder.setKnownKey(false);
signatureResultBuilder.setKeyId(sigList.get(0).getKeyID());
}
}
// check for insecure signing key
// TODO: checks on signingRing ?
if (signatureData != null && ! PgpSecurityConstants.isSecureKey(signatureData.signingKey)) {
log.add(LogType.MSG_DC_INSECURE_KEY, indent + 1);
signatureResultBuilder.setInsecure(true);
}
SignatureChecker signatureChecker = new SignatureChecker();
if (signatureChecker.initializeOnePassSignature(dataChunk, log, indent +1)) {
dataChunk = plainFact.nextObject();
}
@@ -544,16 +474,8 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
return result;
}
int endProgress;
if (signature != null) {
endProgress = 90;
} else if (esResult != null && esResult.encryptedData.isIntegrityProtected()) {
endProgress = 95;
} else {
endProgress = 100;
}
ProgressScaler progressScaler =
new ProgressScaler(mProgressable, currentProgress, endProgress, 100);
new ProgressScaler(mProgressable, currentProgress, 95, 100);
InputStream dataIn = literalData.getInputStream();
@@ -568,9 +490,7 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
}
// update signature buffer if signature is also present
if (signature != null) {
signature.update(buffer, 0, length);
}
signatureChecker.updateSignatureData(buffer, 0, length);
alreadyWritten += length;
if (wholeSize > 0) {
@@ -587,40 +507,17 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
metadata = new OpenPgpMetadata(
originalFilename, mimeType, literalData.getModificationTime().getTime(), alreadyWritten, charset);
if (signatureData != null) {
updateProgress(R.string.progress_verifying_signature, 90, 100);
if (signatureChecker.isInitialized()) {
log.add(LogType.MSG_DC_CLEAR_SIGNATURE_CHECK, indent);
Object o = plainFact.nextObject();
if ( ! (o instanceof PGPSignatureList) ) {
log.add(LogType.MSG_DC_ERROR_NO_SIGNATURE, indent);
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
PGPSignatureList signatureList = (PGPSignatureList) o;
if (signatureList.size() <= signatureData.signatureIndex) {
log.add(LogType.MSG_DC_ERROR_NO_SIGNATURE, indent);
boolean signatureCheckOk = signatureChecker.verifySignature(o, log, indent+1);
if (!signatureCheckOk) {
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
// PGPOnePassSignature and PGPSignature packets are "bracketed",
// so we need to take the last-minus-index'th element here
PGPSignature messageSignature = signatureList.get(signatureList.size() -1 - signatureData.signatureIndex);
// Verify signature
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);
}
// check for insecure hash algorithms
if (!PgpSecurityConstants.isSecureHashAlgorithm(signature.getHashAlgorithm())) {
log.add(LogType.MSG_DC_INSECURE_HASH_ALGO, indent + 1);
signatureResultBuilder.setInsecure(true);
}
signatureResultBuilder.setValidSignature(validSignature);
}
indent -= 1;
@@ -635,7 +532,7 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
log.add(LogType.MSG_DC_ERROR_INTEGRITY_CHECK, indent);
return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log);
}
} else if (signature == null) {
} else if ( ! signatureChecker.isInitialized() ) {
// If no signature is present, we *require* an MDC!
// Handle missing integrity protection like failed integrity protection!
// The MDC packet can be stripped by an attacker!
@@ -652,7 +549,7 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
DecryptVerifyResult result = new DecryptVerifyResult(DecryptVerifyResult.RESULT_OK, log);
result.setCachedCryptoInputParcel(cryptoInput);
result.setSignatureResult(signatureResultBuilder.build());
result.setSignatureResult(signatureChecker.getSignatureResult());
result.setDecryptionResult(decryptionResultBuilder.build());
result.setDecryptionMetadata(metadata);
@@ -1279,21 +1176,131 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
}
public SignatureData findAvailableSignature(PGPOnePassSignatureList sigList) {
// go through all signatures (should be just one), make sure we have
// the key and it matches the one we’re looking for
for (int i = 0; i < sigList.size(); ++i) {
try {
long sigKeyId = sigList.get(i).getKeyID();
CanonicalizedPublicKeyRing signingRing = mProviderHelper.getCanonicalizedPublicKeyRing(
KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(sigKeyId)
);
return new SignatureData(signingRing.getPublicKey(sigKeyId), i);
} catch (ProviderHelper.NotFoundException e) {
Log.d(Constants.TAG, "key not found, trying next signature...");
private class SignatureChecker {
OpenPgpSignatureResultBuilder signatureResultBuilder = new OpenPgpSignatureResultBuilder();
private CanonicalizedPublicKey signingKey;
// we use the signatureIndex instead of the signature itself here for two reasons:
// 1) the signature may be either of type PGPSignature or PGPOnePassSignature (which have no common ancestor)
// 2) in case of the latter, we need the signatureIndex to know which PGPSignature to use later on
private int signatureIndex;
PGPOnePassSignature signature;
boolean initializeOnePassSignature(Object dataChunk, OperationLog log, int indent) throws PGPException {
if ( ! (dataChunk instanceof PGPOnePassSignatureList) ) {
return false;
}
// resolve leading signature data
log.add(LogType.MSG_DC_CLEAR_SIGNATURE, indent +1);
PGPOnePassSignatureList sigList = (PGPOnePassSignatureList) dataChunk;
findAvailableSignature(sigList);
if (signingKey != null) {
// key found in our database!
signature = sigList.get(signatureIndex);
signatureResultBuilder.initValid(signingKey);
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
signature.init(contentVerifierBuilderProvider, signingKey.getPublicKey());
// TODO: checks on signingRing ?
if ( ! PgpSecurityConstants.isSecureKey(signingKey)) {
log.add(LogType.MSG_DC_INSECURE_KEY, indent + 1);
signatureResultBuilder.setInsecure(true);
}
} else if (!sigList.isEmpty()) {
signatureResultBuilder.setSignatureAvailable(true);
signatureResultBuilder.setKnownKey(false);
signatureResultBuilder.setKeyId(sigList.get(0).getKeyID());
}
return true;
}
public boolean isInitialized() {
return signingKey != null;
}
private void findAvailableSignature(PGPOnePassSignatureList sigList) {
// go through all signatures (should be just one), make sure we have
// the key and it matches the one we’re looking for
for (int i = 0; i < sigList.size(); ++i) {
try {
long sigKeyId = sigList.get(i).getKeyID();
CanonicalizedPublicKeyRing signingRing = mProviderHelper.getCanonicalizedPublicKeyRing(
KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(sigKeyId)
);
signatureIndex = i;
signingKey = signingRing.getPublicKey(sigKeyId);
return;
} catch (ProviderHelper.NotFoundException e) {
Log.d(Constants.TAG, "key not found, trying next signature...");
}
}
}
return null;
public void updateSignatureData(byte[] buf, int off, int len) {
if (signature != null) {
signature.update(buf, off, len);
}
}
boolean verifySignature(Object o, OperationLog log, int indent) throws PGPException {
if ( ! (o instanceof PGPSignatureList) ) {
log.add(LogType.MSG_DC_ERROR_NO_SIGNATURE, indent);
return false;
}
PGPSignatureList signatureList = (PGPSignatureList) o;
if (signatureList.size() <= signatureIndex) {
log.add(LogType.MSG_DC_ERROR_NO_SIGNATURE, indent);
return false;
}
// PGPOnePassSignature and PGPSignature packets are "bracketed",
// so we need to take the last-minus-index'th element here
PGPSignature messageSignature = signatureList.get(signatureList.size() -1 - signatureIndex);
// Verify signature
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);
}
// check for insecure hash algorithms
if (!PgpSecurityConstants.isSecureHashAlgorithm(signature.getHashAlgorithm())) {
log.add(LogType.MSG_DC_INSECURE_HASH_ALGO, indent + 1);
signatureResultBuilder.setInsecure(true);
}
signatureResultBuilder.setValidSignature(validSignature);
return true;
}
public byte[] getSigningFingerprint() {
return signingKey.getFingerprint();
}
public OpenPgpSignatureResult getSignatureResult() {
return signatureResultBuilder.build();
}
}
public SignatureData findAvailableSignature(PGPSignatureList sigList) {

1
OpenKeychain/src/main/res/values/strings.xml
View File

@@ -436,7 +436,6 @@
<string name="progress_decrypting">"decrypting data…"</string>
<string name="progress_preparing_signature">"preparing signature…"</string>
<string name="progress_generating_signature">"generating signature…"</string>
<string name="progress_processing_signature">"processing signature…"</string>
<string name="progress_verifying_signature">"verifying signature…"</string>
<string name="progress_signing">"signing…"</string>
<string name="progress_certifying">"certifying…"</string>