1 package org.bouncycastle.asn1; 2 3 import java.io.ByteArrayInputStream; 4 import java.io.FileInputStream; 5 import java.io.IOException; 6 import java.io.InputStream; 7 import java.nio.channels.FileChannel; 8 9 class StreamUtil 10 { 11 // Android-removed: Check max memory at runtime 12 // private static final long MAX_MEMORY = Runtime.getRuntime().maxMemory(); 13 14 /** 15 * Find out possible longest length... 16 * 17 * @param in input stream of interest 18 * @return length calculation or MAX_VALUE. 19 */ findLimit(InputStream in)20 static int findLimit(InputStream in) 21 { 22 if (in instanceof LimitedInputStream) 23 { 24 return ((LimitedInputStream)in).getRemaining(); 25 } 26 else if (in instanceof ASN1InputStream) 27 { 28 return ((ASN1InputStream)in).getLimit(); 29 } 30 else if (in instanceof ByteArrayInputStream) 31 { 32 return ((ByteArrayInputStream)in).available(); 33 } 34 else if (in instanceof FileInputStream) 35 { 36 try 37 { 38 FileChannel channel = ((FileInputStream)in).getChannel(); 39 long size = (channel != null) ? channel.size() : Integer.MAX_VALUE; 40 41 if (size < Integer.MAX_VALUE) 42 { 43 return (int)size; 44 } 45 } 46 catch (IOException e) 47 { 48 // ignore - they'll find out soon enough! 49 } 50 } 51 52 // BEGIN Android-changed: Check max memory at runtime 53 long maxMemory = Runtime.getRuntime().maxMemory(); 54 if (maxMemory > Integer.MAX_VALUE) 55 { 56 return Integer.MAX_VALUE; 57 } 58 59 return (int) maxMemory; 60 // END Android-changed: Check max memory at runtime 61 } 62 calculateBodyLength( int length)63 static int calculateBodyLength( 64 int length) 65 { 66 int count = 1; 67 68 if (length > 127) 69 { 70 int size = 1; 71 int val = length; 72 73 while ((val >>>= 8) != 0) 74 { 75 size++; 76 } 77 78 for (int i = (size - 1) * 8; i >= 0; i -= 8) 79 { 80 count++; 81 } 82 } 83 84 return count; 85 } 86 calculateTagLength(int tagNo)87 static int calculateTagLength(int tagNo) 88 throws IOException 89 { 90 int length = 1; 91 92 if (tagNo >= 31) 93 { 94 if (tagNo < 128) 95 { 96 length++; 97 } 98 else 99 { 100 byte[] stack = new byte[5]; 101 int pos = stack.length; 102 103 stack[--pos] = (byte)(tagNo & 0x7F); 104 105 do 106 { 107 tagNo >>= 7; 108 stack[--pos] = (byte)(tagNo & 0x7F | 0x80); 109 } 110 while (tagNo > 127); 111 112 length += stack.length - pos; 113 } 114 } 115 116 return length; 117 } 118 } 119