1 | package br.gov.serpro.util; |
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2 | |
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3 | public class Base64Utils { |
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4 | |
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5 | private static byte[] mBase64EncMap, mBase64DecMap; |
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6 | |
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7 | /** |
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8 | * Class initializer. Initializes the Base64 alphabet (specified in RFC-2045). |
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9 | */ |
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10 | static { |
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11 | byte[] base64Map = { |
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12 | (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', |
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13 | (byte)'G', (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', |
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14 | (byte)'M', (byte)'N', (byte)'O', (byte)'P', (byte)'Q', (byte)'R', |
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15 | (byte)'S', (byte)'T', (byte)'U', (byte)'V', (byte)'W', (byte)'X', |
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16 | (byte)'Y', (byte)'Z', |
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17 | (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', |
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18 | (byte)'g', (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', |
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19 | (byte)'m', (byte)'n', (byte)'o', (byte)'p', (byte)'q', (byte)'r', |
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20 | (byte)'s', (byte)'t', (byte)'u', (byte)'v', (byte)'w', (byte)'x', |
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21 | (byte)'y', (byte)'z', |
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22 | (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5', |
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23 | (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/' }; |
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24 | mBase64EncMap = base64Map; |
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25 | mBase64DecMap = new byte[128]; |
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26 | for (int i=0; i<mBase64EncMap.length; i++) |
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27 | mBase64DecMap[mBase64EncMap[i]] = (byte) i; |
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28 | } |
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29 | |
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30 | /** |
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31 | * This class isn't meant to be instantiated. |
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32 | */ |
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33 | private Base64Utils() { |
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34 | } |
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35 | |
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36 | /** |
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37 | * Encodes the given byte[] using the Base64-encoding, |
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38 | * as specified in RFC-2045 (Section 6.8). |
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39 | * |
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40 | * @param aData the data to be encoded |
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41 | * @return the Base64-encoded <var>aData</var> |
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42 | * @exception IllegalArgumentException if NULL or empty array is passed |
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43 | */ |
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44 | public static String base64Encode(byte[] aData) { |
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45 | if ((aData == null) || (aData.length == 0)) |
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46 | throw new IllegalArgumentException("Can not encode NULL or empty byte array."); |
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47 | |
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48 | byte encodedBuf[] = new byte[((aData.length+2)/3)*4]; |
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49 | |
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50 | // 3-byte to 4-byte conversion |
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51 | int srcIndex, destIndex; |
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52 | for (srcIndex=0, destIndex=0; srcIndex < aData.length-2; srcIndex += 3) { |
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53 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex] >>> 2) & 077]; |
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54 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex+1] >>> 4) & 017 | |
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55 | (aData[srcIndex] << 4) & 077]; |
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56 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex+2] >>> 6) & 003 | |
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57 | (aData[srcIndex+1] << 2) & 077]; |
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58 | encodedBuf[destIndex++] = mBase64EncMap[aData[srcIndex+2] & 077]; |
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59 | } |
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60 | |
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61 | // Convert the last 1 or 2 bytes |
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62 | if (srcIndex < aData.length) { |
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63 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex] >>> 2) & 077]; |
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64 | if (srcIndex < aData.length-1) { |
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65 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex+1] >>> 4) & 017 | |
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66 | (aData[srcIndex] << 4) & 077]; |
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67 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex+1] << 2) & 077]; |
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68 | } |
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69 | else { |
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70 | encodedBuf[destIndex++] = mBase64EncMap[(aData[srcIndex] << 4) & 077]; |
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71 | } |
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72 | } |
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73 | |
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74 | // Add padding to the end of encoded data |
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75 | while (destIndex < encodedBuf.length) { |
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76 | encodedBuf[destIndex] = (byte) '='; |
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77 | destIndex++; |
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78 | } |
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79 | |
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80 | String result = new String(encodedBuf); |
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81 | return result; |
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82 | } |
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83 | |
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84 | |
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85 | /** |
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86 | * Decodes the given Base64-encoded data, |
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87 | * as specified in RFC-2045 (Section 6.8). |
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88 | * |
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89 | * @param aData the Base64-encoded aData. |
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90 | * @return the decoded <var>aData</var>. |
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91 | * @exception IllegalArgumentException if NULL or empty data is passed |
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92 | */ |
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93 | public static byte[] base64Decode(String aData) { |
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94 | if ((aData == null) || (aData.length() == 0)) |
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95 | throw new IllegalArgumentException("Can not decode NULL or empty string."); |
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96 | |
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97 | byte[] data = aData.getBytes(); |
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98 | |
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99 | // Skip padding from the end of encoded data |
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100 | int tail = data.length; |
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101 | while (data[tail-1] == '=') |
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102 | tail--; |
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103 | |
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104 | byte decodedBuf[] = new byte[tail - data.length/4]; |
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105 | |
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106 | // ASCII-printable to 0-63 conversion |
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107 | for (int i = 0; i < data.length; i++) |
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108 | data[i] = mBase64DecMap[data[i]]; |
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109 | |
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110 | // 4-byte to 3-byte conversion |
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111 | int srcIndex, destIndex; |
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112 | for (srcIndex = 0, destIndex=0; destIndex < decodedBuf.length-2; |
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113 | srcIndex += 4, destIndex += 3) { |
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114 | decodedBuf[destIndex] = (byte) ( ((data[srcIndex] << 2) & 255) | |
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115 | ((data[srcIndex+1] >>> 4) & 003) ); |
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116 | decodedBuf[destIndex+1] = (byte) ( ((data[srcIndex+1] << 4) & 255) | |
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117 | ((data[srcIndex+2] >>> 2) & 017) ); |
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118 | decodedBuf[destIndex+2] = (byte) ( ((data[srcIndex+2] << 6) & 255) | |
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119 | (data[srcIndex+3] & 077) ); |
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120 | } |
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121 | |
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122 | // Handle last 1 or 2 bytes |
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123 | if (destIndex < decodedBuf.length) |
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124 | decodedBuf[destIndex] = (byte) ( ((data[srcIndex] << 2) & 255) | |
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125 | ((data[srcIndex+1] >>> 4) & 003) ); |
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126 | if (++destIndex < decodedBuf.length) |
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127 | decodedBuf[destIndex] = (byte) ( ((data[srcIndex+1] << 4) & 255) | |
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128 | ((data[srcIndex+2] >>> 2) & 017) ); |
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129 | |
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130 | return decodedBuf; |
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131 | } |
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132 | |
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133 | public static String der2pem(byte[] der){ |
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134 | |
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135 | int begin = 0; |
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136 | int lineSize = 64; |
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137 | int end = lineSize; |
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138 | int bytesWriten = 0; |
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139 | |
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140 | |
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141 | String LF = "\n"; |
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142 | String beginCertificate = "-----BEGIN CERTIFICATE-----" +LF; |
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143 | String endCertificate = "-----END CERTIFICATE-----"; |
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144 | |
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145 | String base64encoded = Base64Utils.base64Encode(der); |
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146 | |
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147 | StringBuilder sb = new StringBuilder(); |
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148 | sb.append(beginCertificate); |
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149 | |
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150 | |
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151 | do { |
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152 | |
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153 | if (base64encoded.length() - begin < end - begin){ |
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154 | end = base64encoded.length(); |
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155 | } |
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156 | |
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157 | String subs = base64encoded.substring(begin, end); |
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158 | sb.append(subs + LF); |
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159 | bytesWriten += end - begin; |
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160 | begin = end; |
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161 | end += lineSize; |
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162 | |
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163 | } while (bytesWriten != base64encoded.length()); |
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164 | |
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165 | sb.append(endCertificate); |
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166 | |
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167 | return sb.toString(); |
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168 | |
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169 | |
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170 | } |
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171 | |
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172 | } |
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