1/* 2 * Copyright 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package libcore.java.security; 18 19import static java.nio.charset.StandardCharsets.UTF_8; 20 21import java.io.BufferedReader; 22import java.io.FileReader; 23import java.io.IOException; 24import java.io.InputStreamReader; 25import java.lang.reflect.InvocationTargetException; 26import java.lang.reflect.Method; 27import java.util.Arrays; 28import java.util.List; 29import java.util.regex.Matcher; 30import java.util.regex.Pattern; 31 32public class CpuFeatures { 33 private CpuFeatures() {} 34 35 public static boolean isAESHardwareAccelerated() { 36 List<String> features = getListFromCpuinfo("Features"); 37 if (features != null && features.contains("aes")) { 38 return true; 39 } 40 41 List<String> flags = getListFromCpuinfo("flags"); 42 if (flags != null && flags.contains("aes")) { 43 return true; 44 } 45 46 features = getCpuFeaturesMac(); 47 if (features != null && features.contains("aes")) { 48 return true; 49 } 50 51 // If we're in an emulated ABI, Conscrypt's NativeCrypto might bridge to 52 // a library that has accelerated AES instructions. See if Conscrypt 53 // detects that condition. 54 Class<?> nativeCrypto = findNativeCrypto(); 55 if (nativeCrypto != null) { 56 try { 57 Method EVP_has_aes_hardware = 58 nativeCrypto.getDeclaredMethod("EVP_has_aes_hardware"); 59 EVP_has_aes_hardware.setAccessible(true); 60 return ((Integer) EVP_has_aes_hardware.invoke(null)) == 1; 61 } catch (NoSuchMethodException ignored) { 62 } catch (SecurityException ignored) { 63 } catch (IllegalAccessException ignored) { 64 } catch (IllegalArgumentException ignored) { 65 } catch (InvocationTargetException e) { 66 throw new IllegalArgumentException(e); 67 } 68 } 69 70 return false; 71 } 72 73 private static Class<?> findNativeCrypto() { 74 for (String packageName : new String[]{"com.android.org.conscrypt", "org.conscrypt"}) { 75 String name = packageName + ".NativeCrypto"; 76 try { 77 return Class.forName(name); 78 } catch (ClassNotFoundException e) { 79 // Try the next one. 80 } 81 } 82 return null; 83 } 84 85 private static String getFieldFromCpuinfo(String field) { 86 try { 87 @SuppressWarnings("DefaultCharset") 88 BufferedReader br = new BufferedReader(new FileReader("/proc/cpuinfo")); 89 Pattern p = Pattern.compile(field + "\\s*:\\s*(.*)"); 90 91 try { 92 String line; 93 while ((line = br.readLine()) != null) { 94 Matcher m = p.matcher(line); 95 if (m.matches()) { 96 return m.group(1); 97 } 98 } 99 } finally { 100 br.close(); 101 } 102 } catch (IOException ignored) { 103 // Ignored. 104 } 105 106 return null; 107 } 108 109 private static List<String> getListFromCpuinfo(String fieldName) { 110 String features = getFieldFromCpuinfo(fieldName); 111 if (features == null) 112 return null; 113 114 return Arrays.asList(features.split("\\s")); 115 } 116 117 private static List<String> getCpuFeaturesMac() { 118 try { 119 StringBuilder output = new StringBuilder(); 120 Process proc = Runtime.getRuntime().exec("sysctl -a"); 121 if (proc.waitFor() == 0) { 122 BufferedReader reader = 123 new BufferedReader(new InputStreamReader(proc.getInputStream(), UTF_8)); 124 125 final String linePrefix = "machdep.cpu.features:"; 126 127 String line; 128 while ((line = reader.readLine()) != null) { 129 line = line.toLowerCase(); 130 if (line.startsWith(linePrefix)) { 131 // Strip the line prefix from the results. 132 output.append(line.substring(linePrefix.length())).append(' '); 133 } 134 } 135 if (output.length() > 0) { 136 String outputString = output.toString(); 137 String[] parts = outputString.split("\\s+"); 138 return Arrays.asList(parts); 139 } 140 } 141 } catch (Exception ignored) { 142 // Ignored. 143 } 144 145 return null; 146 } 147} 148