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author | Mattias Nissler <mnissler@google.com> | 2016-02-24 14:45:06 +0100 |
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committer | Mattias Nissler <mnissler@google.com> | 2016-02-24 14:53:10 +0100 |
commit | 03b72b0f377d352a7197b2cbb3c90ebed3321bcc (patch) | |
tree | 17deccfc3425d171a8df152db6539d1c22f4c09a /tools/dumpkey | |
parent | Merge "Surpress warnings in minzip/Zip.c" (diff) | |
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Diffstat (limited to '')
-rw-r--r-- | tools/dumpkey/Android.mk | 32 | ||||
-rw-r--r-- | tools/dumpkey/DumpPublicKey.java | 270 | ||||
-rw-r--r-- | tools/dumpkey/DumpPublicKey.mf | 1 |
3 files changed, 303 insertions, 0 deletions
diff --git a/tools/dumpkey/Android.mk b/tools/dumpkey/Android.mk new file mode 100644 index 000000000..bbd065664 --- /dev/null +++ b/tools/dumpkey/Android.mk @@ -0,0 +1,32 @@ +# 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 diff --git a/tools/dumpkey/DumpPublicKey.java b/tools/dumpkey/DumpPublicKey.java new file mode 100644 index 000000000..3eb139842 --- /dev/null +++ b/tools/dumpkey/DumpPublicKey.java @@ -0,0 +1,270 @@ +/* + * 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); + } +} diff --git a/tools/dumpkey/DumpPublicKey.mf b/tools/dumpkey/DumpPublicKey.mf new file mode 100644 index 000000000..7bb3bc88d --- /dev/null +++ b/tools/dumpkey/DumpPublicKey.mf @@ -0,0 +1 @@ +Main-Class: com.android.dumpkey.DumpPublicKey |