tools/dumpkey/DumpPublicKey.java - android_bootable_recovery - Gitiles

 /*
  * 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);
     }
 }
	/*
	* 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);
	}
	}