Merge "Move dumpkey tool to the recovery repo."

# Copyright (C) 2008 The Android Open Source Project

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#      http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

LOCAL_PATH := $(call my-dir)

# Determine whether to build dumpkey from system/core/libmincrypt or from

# bootable/recovery/tools. The dumpkey source is temporarily present in both

# locations during the process of moving the tool to the recovery repository.

# TODO(mnissler): Remove the guard after the transition is complete.

ifndef BUILD_DUMPKEY_FROM_RECOVERY

BUILD_DUMPKEY_FROM_RECOVERY := true

endif

ifeq ($(BUILD_DUMPKEY_FROM_RECOVERY),true)

include $(CLEAR_VARS)

LOCAL_MODULE := dumpkey

LOCAL_SRC_FILES := DumpPublicKey.java

LOCAL_JAR_MANIFEST := DumpPublicKey.mf

LOCAL_STATIC_JAVA_LIBRARIES := bouncycastle-host

include $(BUILD_HOST_JAVA_LIBRARY)

endif

/*

 * Copyright (C) 2008 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.android.dumpkey;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.io.FileInputStream;

import java.math.BigInteger;

import java.security.cert.CertificateFactory;

import java.security.cert.X509Certificate;

import java.security.KeyStore;

import java.security.Key;

import java.security.PublicKey;

import java.security.Security;

import java.security.interfaces.ECPublicKey;

import java.security.interfaces.RSAPublicKey;

import java.security.spec.ECPoint;

/**

 * Command line tool to extract RSA public keys from X.509 certificates

 * and output source code with data initializers for the keys.

 * @hide

 */

class DumpPublicKey {

    /**

     * @param key to perform sanity checks on

     * @return version number of key.  Supported versions are:

     *     1: 2048-bit RSA key with e=3 and SHA-1 hash

     *     2: 2048-bit RSA key with e=65537 and SHA-1 hash

     *     3: 2048-bit RSA key with e=3 and SHA-256 hash

     *     4: 2048-bit RSA key with e=65537 and SHA-256 hash

     * @throws Exception if the key has the wrong size or public exponent

     */

    static int checkRSA(RSAPublicKey key, boolean useSHA256) throws Exception {

        BigInteger pubexp = key.getPublicExponent();

        BigInteger modulus = key.getModulus();

        int version;

        if (pubexp.equals(BigInteger.valueOf(3))) {

            version = useSHA256 ? 3 : 1;

        } else if (pubexp.equals(BigInteger.valueOf(65537))) {

            version = useSHA256 ? 4 : 2;

        } else {

            throw new Exception("Public exponent should be 3 or 65537 but is " +

                                pubexp.toString(10) + ".");

        }

        if (modulus.bitLength() != 2048) {

             throw new Exception("Modulus should be 2048 bits long but is " +

                        modulus.bitLength() + " bits.");

        }

        return version;

    }

    /**

     * @param key to perform sanity checks on

     * @return version number of key.  Supported versions are:

     *     5: 256-bit EC key with curve NIST P-256

     * @throws Exception if the key has the wrong size or public exponent

     */

    static int checkEC(ECPublicKey key) throws Exception {

        if (key.getParams().getCurve().getField().getFieldSize() != 256) {

            throw new Exception("Curve must be NIST P-256");

        }

        return 5;

    }

    /**

     * Perform sanity check on public key.

     */

    static int check(PublicKey key, boolean useSHA256) throws Exception {

        if (key instanceof RSAPublicKey) {

            return checkRSA((RSAPublicKey) key, useSHA256);

        } else if (key instanceof ECPublicKey) {

            if (!useSHA256) {

                throw new Exception("Must use SHA-256 with EC keys!");

            }

            return checkEC((ECPublicKey) key);

        } else {

            throw new Exception("Unsupported key class: " + key.getClass().getName());

        }

    }

    /**

     * @param key to output

     * @return a String representing this public key.  If the key is a

     *    version 1 key, the string will be a C initializer; this is

     *    not true for newer key versions.

     */

    static String printRSA(RSAPublicKey key, boolean useSHA256) throws Exception {

        int version = check(key, useSHA256);

        BigInteger N = key.getModulus();

        StringBuilder result = new StringBuilder();

        int nwords = N.bitLength() / 32;    // # of 32 bit integers in modulus

        if (version > 1) {

            result.append("v");

            result.append(Integer.toString(version));

            result.append(" ");

        }

        result.append("{");

        result.append(nwords);

        BigInteger B = BigInteger.valueOf(0x100000000L);  // 2^32

        BigInteger N0inv = B.subtract(N.modInverse(B));   // -1 / N[0] mod 2^32

        result.append(",0x");

        result.append(N0inv.toString(16));

        BigInteger R = BigInteger.valueOf(2).pow(N.bitLength());

        BigInteger RR = R.multiply(R).mod(N);    // 2^4096 mod N

        // Write out modulus as little endian array of integers.

        result.append(",{");

        for (int i = 0; i < nwords; ++i) {

            long n = N.mod(B).longValue();

            result.append(n);

            if (i != nwords - 1) {

                result.append(",");

            }

            N = N.divide(B);

        }

        result.append("}");

        // Write R^2 as little endian array of integers.

        result.append(",{");

        for (int i = 0; i < nwords; ++i) {

            long rr = RR.mod(B).longValue();

            result.append(rr);

            if (i != nwords - 1) {

                result.append(",");

            }

            RR = RR.divide(B);

        }

        result.append("}");

        result.append("}");

        return result.toString();

    }

    /**

     * @param key to output

     * @return a String representing this public key.  If the key is a

     *    version 1 key, the string will be a C initializer; this is

     *    not true for newer key versions.

     */

    static String printEC(ECPublicKey key) throws Exception {

        int version = checkEC(key);

        StringBuilder result = new StringBuilder();

        result.append("v");

        result.append(Integer.toString(version));

        result.append(" ");

        BigInteger X = key.getW().getAffineX();

        BigInteger Y = key.getW().getAffineY();

        int nbytes = key.getParams().getCurve().getField().getFieldSize() / 8;    // # of 32 bit integers in X coordinate

        result.append("{");

        result.append(nbytes);

        BigInteger B = BigInteger.valueOf(0x100L);  // 2^8

        // Write out Y coordinate as array of characters.

        result.append(",{");

        for (int i = 0; i < nbytes; ++i) {

            long n = X.mod(B).longValue();

            result.append(n);

            if (i != nbytes - 1) {

                result.append(",");

            }

            X = X.divide(B);

        }

        result.append("}");

        // Write out Y coordinate as array of characters.

        result.append(",{");

        for (int i = 0; i < nbytes; ++i) {

            long n = Y.mod(B).longValue();

            result.append(n);

            if (i != nbytes - 1) {

                result.append(",");

            }

            Y = Y.divide(B);

        }

        result.append("}");

        result.append("}");

        return result.toString();

    }

    static String print(PublicKey key, boolean useSHA256) throws Exception {

        if (key instanceof RSAPublicKey) {

            return printRSA((RSAPublicKey) key, useSHA256);

        } else if (key instanceof ECPublicKey) {

            return printEC((ECPublicKey) key);

        } else {

            throw new Exception("Unsupported key class: " + key.getClass().getName());

        }

    }

    public static void main(String[] args) {

        if (args.length < 1) {

            System.err.println("Usage: DumpPublicKey certfile ... > source.c");

            System.exit(1);

        }

        Security.addProvider(new BouncyCastleProvider());

        try {

            for (int i = 0; i < args.length; i++) {

                FileInputStream input = new FileInputStream(args[i]);

                CertificateFactory cf = CertificateFactory.getInstance("X.509");

                X509Certificate cert = (X509Certificate) cf.generateCertificate(input);

                boolean useSHA256 = false;

                String sigAlg = cert.getSigAlgName();

                if ("SHA1withRSA".equals(sigAlg) || "MD5withRSA".equals(sigAlg)) {

                    // SignApk has historically accepted "MD5withRSA"

                    // certificates, but treated them as "SHA1withRSA"

                    // anyway.  Continue to do so for backwards

                    // compatibility.

                  useSHA256 = false;

                } else if ("SHA256withRSA".equals(sigAlg) || "SHA256withECDSA".equals(sigAlg)) {

                  useSHA256 = true;

                } else {

                  System.err.println(args[i] + ": unsupported signature algorithm \"" +

                                     sigAlg + "\"");

                  System.exit(1);

                }

                PublicKey key = cert.getPublicKey();

                check(key, useSHA256);

                System.out.print(print(key, useSHA256));

                System.out.println(i < args.length - 1 ? "," : "");

            }

        } catch (Exception e) {

            e.printStackTrace();

            System.exit(1);

        }

        System.exit(0);

    }

}

Main-Class: com.android.dumpkey.DumpPublicKey