Examples with GuaranteedEncodedFormX509Certificate com.android.apksig.internal.util.GuaranteedEncodedFormX509Certificate used on opensource projects

Example 6 with GuaranteedEncodedFormX509Certificate

use of com.android.apksig.internal.util.GuaranteedEncodedFormX509Certificate in project apksig by venshine.

the class Certificate method parseCertificates.

public static List<X509Certificate> parseCertificates(List<Asn1OpaqueObject> encodedCertificates) throws CertificateException {
    if (encodedCertificates.isEmpty()) {
        return Collections.emptyList();
    }
    List<X509Certificate> result = new ArrayList<>(encodedCertificates.size());
    for (int i = 0; i < encodedCertificates.size(); i++) {
        Asn1OpaqueObject encodedCertificate = encodedCertificates.get(i);
        X509Certificate certificate;
        byte[] encodedForm = ByteBufferUtils.toByteArray(encodedCertificate.getEncoded());
        try {
            certificate = X509CertificateUtils.generateCertificate(encodedForm);
        } catch (CertificateException e) {
            throw new CertificateException("Failed to parse certificate #" + (i + 1), e);
        }
        // Wrap the cert so that the result's getEncoded returns exactly the original
        // encoded form. Without this, getEncoded may return a different form from what was
        // stored in the signature. This is because some X509Certificate(Factory)
        // implementations re-encode certificates and/or some implementations of
        // X509Certificate.getEncoded() re-encode certificates.
        certificate = new GuaranteedEncodedFormX509Certificate(certificate, encodedForm);
        result.add(certificate);
    }
    return result;
}

Example 7 with GuaranteedEncodedFormX509Certificate

use of com.android.apksig.internal.util.GuaranteedEncodedFormX509Certificate in project apksig by venshine.

the class V2SchemeVerifier method parseSigner.

/**
 * Parses the provided signer block and populates the {@code result}.
 *
 * <p>This verifies signatures over {@code signed-data} contained in this block but does not
 * verify the integrity of the rest of the APK. To facilitate APK integrity verification, this
 * method adds the {@code contentDigestsToVerify}. These digests can then be used to verify the
 * integrity of the APK.
 *
 * <p>This method adds one or more errors to the {@code result} if a verification error is
 * expected to be encountered on an Android platform version in the
 * {@code [minSdkVersion, maxSdkVersion]} range.
 */
private static void parseSigner(ByteBuffer signerBlock, CertificateFactory certFactory, ApkSigningBlockUtils.Result.SignerInfo result, Set<ContentDigestAlgorithm> contentDigestsToVerify, Map<Integer, String> supportedApkSigSchemeNames, Set<Integer> foundApkSigSchemeIds, int minSdkVersion, int maxSdkVersion) throws ApkFormatException, NoSuchAlgorithmException {
    ByteBuffer signedData = ApkSigningBlockUtils.getLengthPrefixedSlice(signerBlock);
    byte[] signedDataBytes = new byte[signedData.remaining()];
    signedData.get(signedDataBytes);
    signedData.flip();
    result.signedData = signedDataBytes;
    ByteBuffer signatures = ApkSigningBlockUtils.getLengthPrefixedSlice(signerBlock);
    byte[] publicKeyBytes = ApkSigningBlockUtils.readLengthPrefixedByteArray(signerBlock);
    // Parse the signatures block and identify supported signatures
    int signatureCount = 0;
    List<ApkSigningBlockUtils.SupportedSignature> supportedSignatures = new ArrayList<>(1);
    while (signatures.hasRemaining()) {
        signatureCount++;
        try {
            ByteBuffer signature = ApkSigningBlockUtils.getLengthPrefixedSlice(signatures);
            int sigAlgorithmId = signature.getInt();
            byte[] sigBytes = ApkSigningBlockUtils.readLengthPrefixedByteArray(signature);
            result.signatures.add(new ApkSigningBlockUtils.Result.SignerInfo.Signature(sigAlgorithmId, sigBytes));
            SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.findById(sigAlgorithmId);
            if (signatureAlgorithm == null) {
                result.addWarning(Issue.V2_SIG_UNKNOWN_SIG_ALGORITHM, sigAlgorithmId);
                continue;
            }
            supportedSignatures.add(new ApkSigningBlockUtils.SupportedSignature(signatureAlgorithm, sigBytes));
        } catch (ApkFormatException | BufferUnderflowException e) {
            result.addError(Issue.V2_SIG_MALFORMED_SIGNATURE, signatureCount);
            return;
        }
    }
    if (result.signatures.isEmpty()) {
        result.addError(Issue.V2_SIG_NO_SIGNATURES);
        return;
    }
    // Verify signatures over signed-data block using the public key
    List<ApkSigningBlockUtils.SupportedSignature> signaturesToVerify = null;
    try {
        signaturesToVerify = ApkSigningBlockUtils.getSignaturesToVerify(supportedSignatures, minSdkVersion, maxSdkVersion);
    } catch (ApkSigningBlockUtils.NoSupportedSignaturesException e) {
        result.addError(Issue.V2_SIG_NO_SUPPORTED_SIGNATURES, e);
        return;
    }
    for (ApkSigningBlockUtils.SupportedSignature signature : signaturesToVerify) {
        SignatureAlgorithm signatureAlgorithm = signature.algorithm;
        String jcaSignatureAlgorithm = signatureAlgorithm.getJcaSignatureAlgorithmAndParams().getFirst();
        AlgorithmParameterSpec jcaSignatureAlgorithmParams = signatureAlgorithm.getJcaSignatureAlgorithmAndParams().getSecond();
        String keyAlgorithm = signatureAlgorithm.getJcaKeyAlgorithm();
        PublicKey publicKey;
        try {
            publicKey = KeyFactory.getInstance(keyAlgorithm).generatePublic(new X509EncodedKeySpec(publicKeyBytes));
        } catch (Exception e) {
            result.addError(Issue.V2_SIG_MALFORMED_PUBLIC_KEY, e);
            return;
        }
        try {
            Signature sig = Signature.getInstance(jcaSignatureAlgorithm);
            sig.initVerify(publicKey);
            if (jcaSignatureAlgorithmParams != null) {
                sig.setParameter(jcaSignatureAlgorithmParams);
            }
            signedData.position(0);
            sig.update(signedData);
            byte[] sigBytes = signature.signature;
            if (!sig.verify(sigBytes)) {
                result.addError(Issue.V2_SIG_DID_NOT_VERIFY, signatureAlgorithm);
                return;
            }
            result.verifiedSignatures.put(signatureAlgorithm, sigBytes);
            contentDigestsToVerify.add(signatureAlgorithm.getContentDigestAlgorithm());
        } catch (InvalidKeyException | InvalidAlgorithmParameterException | SignatureException e) {
            result.addError(Issue.V2_SIG_VERIFY_EXCEPTION, signatureAlgorithm, e);
            return;
        }
    }
    // At least one signature over signedData has verified. We can now parse signed-data.
    signedData.position(0);
    ByteBuffer digests = ApkSigningBlockUtils.getLengthPrefixedSlice(signedData);
    ByteBuffer certificates = ApkSigningBlockUtils.getLengthPrefixedSlice(signedData);
    ByteBuffer additionalAttributes = ApkSigningBlockUtils.getLengthPrefixedSlice(signedData);
    // Parse the certificates block
    int certificateIndex = -1;
    while (certificates.hasRemaining()) {
        certificateIndex++;
        byte[] encodedCert = ApkSigningBlockUtils.readLengthPrefixedByteArray(certificates);
        X509Certificate certificate;
        try {
            certificate = X509CertificateUtils.generateCertificate(encodedCert, certFactory);
        } catch (CertificateException e) {
            result.addError(Issue.V2_SIG_MALFORMED_CERTIFICATE, certificateIndex, certificateIndex + 1, e);
            return;
        }
        // Wrap the cert so that the result's getEncoded returns exactly the original encoded
        // form. Without this, getEncoded may return a different form from what was stored in
        // the signature. This is because some X509Certificate(Factory) implementations
        // re-encode certificates.
        certificate = new GuaranteedEncodedFormX509Certificate(certificate, encodedCert);
        result.certs.add(certificate);
    }
    if (result.certs.isEmpty()) {
        result.addError(Issue.V2_SIG_NO_CERTIFICATES);
        return;
    }
    X509Certificate mainCertificate = result.certs.get(0);
    byte[] certificatePublicKeyBytes;
    try {
        certificatePublicKeyBytes = ApkSigningBlockUtils.encodePublicKey(mainCertificate.getPublicKey());
    } catch (InvalidKeyException e) {
        System.out.println("Caught an exception encoding the public key: " + e);
        e.printStackTrace();
        certificatePublicKeyBytes = mainCertificate.getPublicKey().getEncoded();
    }
    if (!Arrays.equals(publicKeyBytes, certificatePublicKeyBytes)) {
        result.addError(Issue.V2_SIG_PUBLIC_KEY_MISMATCH_BETWEEN_CERTIFICATE_AND_SIGNATURES_RECORD, ApkSigningBlockUtils.toHex(certificatePublicKeyBytes), ApkSigningBlockUtils.toHex(publicKeyBytes));
        return;
    }
    // Parse the digests block
    int digestCount = 0;
    while (digests.hasRemaining()) {
        digestCount++;
        try {
            ByteBuffer digest = ApkSigningBlockUtils.getLengthPrefixedSlice(digests);
            int sigAlgorithmId = digest.getInt();
            byte[] digestBytes = ApkSigningBlockUtils.readLengthPrefixedByteArray(digest);
            result.contentDigests.add(new ApkSigningBlockUtils.Result.SignerInfo.ContentDigest(sigAlgorithmId, digestBytes));
        } catch (ApkFormatException | BufferUnderflowException e) {
            result.addError(Issue.V2_SIG_MALFORMED_DIGEST, digestCount);
            return;
        }
    }
    List<Integer> sigAlgsFromSignaturesRecord = new ArrayList<>(result.signatures.size());
    for (ApkSigningBlockUtils.Result.SignerInfo.Signature signature : result.signatures) {
        sigAlgsFromSignaturesRecord.add(signature.getAlgorithmId());
    }
    List<Integer> sigAlgsFromDigestsRecord = new ArrayList<>(result.contentDigests.size());
    for (ApkSigningBlockUtils.Result.SignerInfo.ContentDigest digest : result.contentDigests) {
        sigAlgsFromDigestsRecord.add(digest.getSignatureAlgorithmId());
    }
    if (!sigAlgsFromSignaturesRecord.equals(sigAlgsFromDigestsRecord)) {
        result.addError(Issue.V2_SIG_SIG_ALG_MISMATCH_BETWEEN_SIGNATURES_AND_DIGESTS_RECORDS, sigAlgsFromSignaturesRecord, sigAlgsFromDigestsRecord);
        return;
    }
    // Parse the additional attributes block.
    int additionalAttributeCount = 0;
    Set<Integer> supportedApkSigSchemeIds = supportedApkSigSchemeNames.keySet();
    Set<Integer> supportedExpectedApkSigSchemeIds = new HashSet<>(1);
    while (additionalAttributes.hasRemaining()) {
        additionalAttributeCount++;
        try {
            ByteBuffer attribute = ApkSigningBlockUtils.getLengthPrefixedSlice(additionalAttributes);
            int id = attribute.getInt();
            byte[] value = ByteBufferUtils.toByteArray(attribute);
            result.additionalAttributes.add(new ApkSigningBlockUtils.Result.SignerInfo.AdditionalAttribute(id, value));
            switch(id) {
                case V2SchemeConstants.STRIPPING_PROTECTION_ATTR_ID:
                    // stripping protection added when signing with a newer scheme
                    int foundId = ByteBuffer.wrap(value).order(ByteOrder.LITTLE_ENDIAN).getInt();
                    if (supportedApkSigSchemeIds.contains(foundId)) {
                        supportedExpectedApkSigSchemeIds.add(foundId);
                    } else {
                        result.addWarning(Issue.V2_SIG_UNKNOWN_APK_SIG_SCHEME_ID, result.index, foundId);
                    }
                    break;
                default:
                    result.addWarning(Issue.V2_SIG_UNKNOWN_ADDITIONAL_ATTRIBUTE, id);
            }
        } catch (ApkFormatException | BufferUnderflowException e) {
            result.addError(Issue.V2_SIG_MALFORMED_ADDITIONAL_ATTRIBUTE, additionalAttributeCount);
            return;
        }
    }
    // make sure that all known IDs indicated in stripping protection have already verified
    for (int id : supportedExpectedApkSigSchemeIds) {
        if (!foundApkSigSchemeIds.contains(id)) {
            String apkSigSchemeName = supportedApkSigSchemeNames.get(id);
            result.addError(Issue.V2_SIG_MISSING_APK_SIG_REFERENCED, result.index, apkSigSchemeName);
        }
    }
}

Example 8 with GuaranteedEncodedFormX509Certificate

use of com.android.apksig.internal.util.GuaranteedEncodedFormX509Certificate in project apksig by venshine.

the class ApkSigningBlockUtils method getApkSignatureBlockSigners.

/**
 * Returns the individual APK signers within the provided {@code signatureBlock} in a {@code
 * List} of {@code Pair} instances where the first element is a {@code List} of {@link
 * X509Certificate}s and the second element is a byte array of the individual signer's block.
 *
 * <p>This method supports any signature block that adheres to the following format up to the
 * signing certificate(s):
 * <pre>
 * * length-prefixed sequence of length-prefixed signers
 *   * length-prefixed signed data
 *     * length-prefixed sequence of length-prefixed digests:
 *       * uint32: signature algorithm ID
 *       * length-prefixed bytes: digest of contents
 *     * length-prefixed sequence of certificates:
 *       * length-prefixed bytes: X.509 certificate (ASN.1 DER encoded).
 * </pre>
 *
 * <p>Note, this is a convenience method to obtain any signers from an existing signature block;
 * the signature of each signer will not be verified.
 *
 * @throws ApkFormatException if an error is encountered while parsing the provided {@code
 * signatureBlock}
 * @throws CertificateException if the signing certificate(s) within an individual signer block
 * cannot be parsed
 */
public static List<Pair<List<X509Certificate>, byte[]>> getApkSignatureBlockSigners(byte[] signatureBlock) throws ApkFormatException, CertificateException {
    ByteBuffer signatureBlockBuffer = ByteBuffer.wrap(signatureBlock);
    signatureBlockBuffer.order(ByteOrder.LITTLE_ENDIAN);
    ByteBuffer signersBuffer = getLengthPrefixedSlice(signatureBlockBuffer);
    List<Pair<List<X509Certificate>, byte[]>> signers = new ArrayList<>();
    while (signersBuffer.hasRemaining()) {
        // Parse the next signer block, save all of its bytes for the resulting List, and
        // rewind the buffer to allow the signing certificate(s) to be parsed.
        ByteBuffer signer = getLengthPrefixedSlice(signersBuffer);
        byte[] signerBytes = new byte[signer.remaining()];
        signer.get(signerBytes);
        signer.rewind();
        ByteBuffer signedData = getLengthPrefixedSlice(signer);
        // The first length prefixed slice is the sequence of digests which are not required
        // when obtaining the signing certificate(s).
        getLengthPrefixedSlice(signedData);
        ByteBuffer certificatesBuffer = getLengthPrefixedSlice(signedData);
        List<X509Certificate> certificates = new ArrayList<>();
        while (certificatesBuffer.hasRemaining()) {
            int certLength = certificatesBuffer.getInt();
            byte[] certBytes = new byte[certLength];
            if (certLength > certificatesBuffer.remaining()) {
                throw new IllegalArgumentException("Cert index " + (certificates.size() + 1) + " under signer index " + (signers.size() + 1) + " size out of range: " + certLength);
            }
            certificatesBuffer.get(certBytes);
            GuaranteedEncodedFormX509Certificate signerCert = new GuaranteedEncodedFormX509Certificate(X509CertificateUtils.generateCertificate(certBytes), certBytes);
            certificates.add(signerCert);
        }
        signers.add(Pair.of(certificates, signerBytes));
    }
    return signers;
}

Example 9 with GuaranteedEncodedFormX509Certificate

use of com.android.apksig.internal.util.GuaranteedEncodedFormX509Certificate in project apksig by venshine.

the class V3SigningCertificateLineage method readSigningCertificateLineage.

/**
 * Deserializes the binary representation of an {@link V3SigningCertificateLineage}. Also
 * verifies that the structure is well-formed, e.g. that the signature for each node is from its
 * parent.
 */
public static List<SigningCertificateNode> readSigningCertificateLineage(ByteBuffer inputBytes) throws IOException {
    List<SigningCertificateNode> result = new ArrayList<>();
    int nodeCount = 0;
    if (inputBytes == null || !inputBytes.hasRemaining()) {
        return null;
    }
    ApkSigningBlockUtils.checkByteOrderLittleEndian(inputBytes);
    // FORMAT (little endian):
    // * uint32: version code
    // * sequence of length-prefixed (uint32): nodes
    // * length-prefixed bytes: signed data
    // * length-prefixed bytes: certificate
    // * uint32: signature algorithm id
    // * uint32: flags
    // * uint32: signature algorithm id (used by to sign next cert in lineage)
    // * length-prefixed bytes: signature over above signed data
    X509Certificate lastCert = null;
    int lastSigAlgorithmId = 0;
    try {
        int version = inputBytes.getInt();
        if (version != CURRENT_VERSION) {
            // we only have one version to worry about right now, so just check it
            throw new IllegalArgumentException("Encoded SigningCertificateLineage has a version" + " different than any of which we are aware");
        }
        HashSet<X509Certificate> certHistorySet = new HashSet<>();
        while (inputBytes.hasRemaining()) {
            nodeCount++;
            ByteBuffer nodeBytes = getLengthPrefixedSlice(inputBytes);
            ByteBuffer signedData = getLengthPrefixedSlice(nodeBytes);
            int flags = nodeBytes.getInt();
            int sigAlgorithmId = nodeBytes.getInt();
            SignatureAlgorithm sigAlgorithm = SignatureAlgorithm.findById(lastSigAlgorithmId);
            byte[] signature = readLengthPrefixedByteArray(nodeBytes);
            if (lastCert != null) {
                // Use previous level cert to verify current level
                String jcaSignatureAlgorithm = sigAlgorithm.getJcaSignatureAlgorithmAndParams().getFirst();
                AlgorithmParameterSpec jcaSignatureAlgorithmParams = sigAlgorithm.getJcaSignatureAlgorithmAndParams().getSecond();
                PublicKey publicKey = lastCert.getPublicKey();
                Signature sig = Signature.getInstance(jcaSignatureAlgorithm);
                sig.initVerify(publicKey);
                if (jcaSignatureAlgorithmParams != null) {
                    sig.setParameter(jcaSignatureAlgorithmParams);
                }
                sig.update(signedData);
                if (!sig.verify(signature)) {
                    throw new SecurityException("Unable to verify signature of certificate #" + nodeCount + " using " + jcaSignatureAlgorithm + " when verifying" + " V3SigningCertificateLineage object");
                }
            }
            signedData.rewind();
            byte[] encodedCert = readLengthPrefixedByteArray(signedData);
            int signedSigAlgorithm = signedData.getInt();
            if (lastCert != null && lastSigAlgorithmId != signedSigAlgorithm) {
                throw new SecurityException("Signing algorithm ID mismatch for certificate #" + nodeBytes + " when verifying V3SigningCertificateLineage object");
            }
            lastCert = X509CertificateUtils.generateCertificate(encodedCert);
            lastCert = new GuaranteedEncodedFormX509Certificate(lastCert, encodedCert);
            if (certHistorySet.contains(lastCert)) {
                throw new SecurityException("Encountered duplicate entries in " + "SigningCertificateLineage at certificate #" + nodeCount + ".  All " + "signing certificates should be unique");
            }
            certHistorySet.add(lastCert);
            lastSigAlgorithmId = sigAlgorithmId;
            result.add(new SigningCertificateNode(lastCert, SignatureAlgorithm.findById(signedSigAlgorithm), SignatureAlgorithm.findById(sigAlgorithmId), signature, flags));
        }
    } catch (ApkFormatException | BufferUnderflowException e) {
        throw new IOException("Failed to parse V3SigningCertificateLineage object", e);
    } catch (NoSuchAlgorithmException | InvalidKeyException | InvalidAlgorithmParameterException | SignatureException e) {
        throw new SecurityException("Failed to verify signature over signed data for certificate #" + nodeCount + " when parsing V3SigningCertificateLineage object", e);
    } catch (CertificateException e) {
        throw new SecurityException("Failed to decode certificate #" + nodeCount + " when parsing V3SigningCertificateLineage object", e);
    }
    return result;
}