| 1 | var xor = require('../xor');
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| 2 | function getBlock(self) {
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| 3 | var out = self._cipher.encryptBlock(self._prev);
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| 4 | incr32(self._prev);
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| 5 | return out;
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| 6 | }
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| 7 | exports.encrypt = function (self, chunk) {
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| 8 | while (self._cache.length < chunk.length) {
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| 9 | self._cache = Buffer.concat([self._cache, getBlock(self)]);
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| 10 | }
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| 11 | var pad = self._cache.slice(0, chunk.length);
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| 12 | self._cache = self._cache.slice(chunk.length);
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| 13 | return xor(chunk, pad);
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| 14 | };
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| 15 | function incr32(iv) {
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| 16 | var len = iv.length;
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| 17 | var item;
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| 18 | while (len--) {
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| 19 | item = iv.readUInt8(len);
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| 20 | if (item === 255) {
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| 21 | iv.writeUInt8(0, len);
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| 22 | } else {
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| 23 | item++;
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| 24 | iv.writeUInt8(item, len);
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| 25 | break;
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| 26 | }
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| 27 | }
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| 28 | } |
| \ | No newline at end of file |