package org.bouncycastle.util.encoders; import java.io.IOException; import java.io.OutputStream; public class Base64 { private static final byte[] encodingTable = { (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G', (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N', (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U', (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z', (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g', (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n', (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u', (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z', (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5', (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/' }; /** * encode the input data producong a base 64 encoded byte array. * * @return a byte array containing the base 64 encoded data. */ public static byte[] encode( byte[] data) { byte[] bytes; int modulus = data.length % 3; if (modulus == 0) { bytes = new byte[4 * data.length / 3]; } else { bytes = new byte[4 * ((data.length / 3) + 1)]; } int dataLength = (data.length - modulus); int a1, a2, a3; for (int i = 0, j = 0; i < dataLength; i += 3, j += 4) { a1 = data[i] & 0xff; a2 = data[i + 1] & 0xff; a3 = data[i + 2] & 0xff; bytes[j] = encodingTable[(a1 >>> 2) & 0x3f]; bytes[j + 1] = encodingTable[((a1 << 4) | (a2 >>> 4)) & 0x3f]; bytes[j + 2] = encodingTable[((a2 << 2) | (a3 >>> 6)) & 0x3f]; bytes[j + 3] = encodingTable[a3 & 0x3f]; } /* * process the tail end. */ int b1, b2, b3; int d1, d2; switch (modulus) { case 0: /* nothing left to do */ break; case 1: d1 = data[data.length - 1] & 0xff; b1 = (d1 >>> 2) & 0x3f; b2 = (d1 << 4) & 0x3f; bytes[bytes.length - 4] = encodingTable[b1]; bytes[bytes.length - 3] = encodingTable[b2]; bytes[bytes.length - 2] = (byte)'='; bytes[bytes.length - 1] = (byte)'='; break; case 2: d1 = data[data.length - 2] & 0xff; d2 = data[data.length - 1] & 0xff; b1 = (d1 >>> 2) & 0x3f; b2 = ((d1 << 4) | (d2 >>> 4)) & 0x3f; b3 = (d2 << 2) & 0x3f; bytes[bytes.length - 4] = encodingTable[b1]; bytes[bytes.length - 3] = encodingTable[b2]; bytes[bytes.length - 2] = encodingTable[b3]; bytes[bytes.length - 1] = (byte)'='; break; } return bytes; } /* * set up the decoding table. */ private static final byte[] decodingTable; static { decodingTable = new byte[128]; for (int i = 'A'; i <= 'Z'; i++) { decodingTable[i] = (byte)(i - 'A'); } for (int i = 'a'; i <= 'z'; i++) { decodingTable[i] = (byte)(i - 'a' + 26); } for (int i = '0'; i <= '9'; i++) { decodingTable[i] = (byte)(i - '0' + 52); } decodingTable['+'] = 62; decodingTable['/'] = 63; } /** * decode the base 64 encoded input data. * * @return a byte array representing the decoded data. */ public static byte[] decode( byte[] data) { // PARG - fix up for zero length encodes/decodes if ( data.length == 0 ){ return( data ); } byte[] bytes; byte b1, b2, b3, b4; if (data[data.length - 2] == '=') { bytes = new byte[(((data.length / 4) - 1) * 3) + 1]; } else if (data[data.length - 1] == '=') { bytes = new byte[(((data.length / 4) - 1) * 3) + 2]; } else { bytes = new byte[((data.length / 4) * 3)]; } for (int i = 0, j = 0; i < data.length - 4; i += 4, j += 3) { b1 = decodingTable[data[i]]; b2 = decodingTable[data[i + 1]]; b3 = decodingTable[data[i + 2]]; b4 = decodingTable[data[i + 3]]; bytes[j] = (byte)((b1 << 2) | (b2 >> 4)); bytes[j + 1] = (byte)((b2 << 4) | (b3 >> 2)); bytes[j + 2] = (byte)((b3 << 6) | b4); } if (data[data.length - 2] == '=') { b1 = decodingTable[data[data.length - 4]]; b2 = decodingTable[data[data.length - 3]]; bytes[bytes.length - 1] = (byte)((b1 << 2) | (b2 >> 4)); } else if (data[data.length - 1] == '=') { b1 = decodingTable[data[data.length - 4]]; b2 = decodingTable[data[data.length - 3]]; b3 = decodingTable[data[data.length - 2]]; bytes[bytes.length - 2] = (byte)((b1 << 2) | (b2 >> 4)); bytes[bytes.length - 1] = (byte)((b2 << 4) | (b3 >> 2)); } else { b1 = decodingTable[data[data.length - 4]]; b2 = decodingTable[data[data.length - 3]]; b3 = decodingTable[data[data.length - 2]]; b4 = decodingTable[data[data.length - 1]]; bytes[bytes.length - 3] = (byte)((b1 << 2) | (b2 >> 4)); bytes[bytes.length - 2] = (byte)((b2 << 4) | (b3 >> 2)); bytes[bytes.length - 1] = (byte)((b3 << 6) | b4); } return bytes; } /** * decode the base 64 encoded String data. * * @return a byte array representing the decoded data. */ public static byte[] decode( String data) { // PARG - fix up for zero length encodes/decodes if ( data.length() == 0 ){ return( new byte[0] ); } byte[] bytes; byte b1, b2, b3, b4; if (data.charAt(data.length() - 2) == '=') { bytes = new byte[(((data.length() / 4) - 1) * 3) + 1]; } else if (data.charAt(data.length() - 1) == '=') { bytes = new byte[(((data.length() / 4) - 1) * 3) + 2]; } else { bytes = new byte[((data.length() / 4) * 3)]; } for (int i = 0, j = 0; i < data.length() - 4; i += 4, j += 3) { b1 = decodingTable[data.charAt(i)]; b2 = decodingTable[data.charAt(i + 1)]; b3 = decodingTable[data.charAt(i + 2)]; b4 = decodingTable[data.charAt(i + 3)]; bytes[j] = (byte)((b1 << 2) | (b2 >> 4)); bytes[j + 1] = (byte)((b2 << 4) | (b3 >> 2)); bytes[j + 2] = (byte)((b3 << 6) | b4); } if (data.charAt(data.length() - 2) == '=') { b1 = decodingTable[data.charAt(data.length() - 4)]; b2 = decodingTable[data.charAt(data.length() - 3)]; bytes[bytes.length - 1] = (byte)((b1 << 2) | (b2 >> 4)); } else if (data.charAt(data.length() - 1) == '=') { b1 = decodingTable[data.charAt(data.length() - 4)]; b2 = decodingTable[data.charAt(data.length() - 3)]; b3 = decodingTable[data.charAt(data.length() - 2)]; bytes[bytes.length - 2] = (byte)((b1 << 2) | (b2 >> 4)); bytes[bytes.length - 1] = (byte)((b2 << 4) | (b3 >> 2)); } else { b1 = decodingTable[data.charAt(data.length() - 4)]; b2 = decodingTable[data.charAt(data.length() - 3)]; b3 = decodingTable[data.charAt(data.length() - 2)]; b4 = decodingTable[data.charAt(data.length() - 1)]; bytes[bytes.length - 3] = (byte)((b1 << 2) | (b2 >> 4)); bytes[bytes.length - 2] = (byte)((b2 << 4) | (b3 >> 2)); bytes[bytes.length - 1] = (byte)((b3 << 6) | b4); } return bytes; } /** * decode the base 64 encoded String data writing it to the given output stream * * @return the number of bytes produced. */ public static int decode( String data, OutputStream out) throws IOException { // PARG if ( data.length()== 0 ){ return( 0 ); } byte b1, b2, b3, b4; int length; if (data.charAt(data.length() - 2) == '=') { length = (((data.length() / 4) - 1) * 3) + 1; } else if (data.charAt(data.length() - 1) == '=') { length = (((data.length() / 4) - 1) * 3) + 2; } else { length = ((data.length() / 4) * 3); } for (int i = 0, j = 0; i < data.length() - 4; i += 4, j += 3) { b1 = decodingTable[data.charAt(i)]; b2 = decodingTable[data.charAt(i + 1)]; b3 = decodingTable[data.charAt(i + 2)]; b4 = decodingTable[data.charAt(i + 3)]; out.write((b1 << 2) | (b2 >> 4)); out.write((b2 << 4) | (b3 >> 2)); out.write((b3 << 6) | b4); } if (data.charAt(data.length() - 2) == '=') { b1 = decodingTable[data.charAt(data.length() - 4)]; b2 = decodingTable[data.charAt(data.length() - 3)]; out.write((b1 << 2) | (b2 >> 4)); } else if (data.charAt(data.length() - 1) == '=') { b1 = decodingTable[data.charAt(data.length() - 4)]; b2 = decodingTable[data.charAt(data.length() - 3)]; b3 = decodingTable[data.charAt(data.length() - 2)]; out.write((b1 << 2) | (b2 >> 4)); out.write((b2 << 4) | (b3 >> 2)); } else { b1 = decodingTable[data.charAt(data.length() - 4)]; b2 = decodingTable[data.charAt(data.length() - 3)]; b3 = decodingTable[data.charAt(data.length() - 2)]; b4 = decodingTable[data.charAt(data.length() - 1)]; out.write((b1 << 2) | (b2 >> 4)); out.write((b2 << 4) | (b3 >> 2)); out.write((b3 << 6) | b4); } return length; } }