46 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			46 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| var Buffer = require('safe-buffer').Buffer
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| var MD5 = require('md5.js')
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| 
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| /* eslint-disable camelcase */
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| function EVP_BytesToKey (password, salt, keyBits, ivLen) {
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|   if (!Buffer.isBuffer(password)) password = Buffer.from(password, 'binary')
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|   if (salt) {
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|     if (!Buffer.isBuffer(salt)) salt = Buffer.from(salt, 'binary')
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|     if (salt.length !== 8) throw new RangeError('salt should be Buffer with 8 byte length')
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|   }
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| 
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|   var keyLen = keyBits / 8
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|   var key = Buffer.alloc(keyLen)
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|   var iv = Buffer.alloc(ivLen || 0)
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|   var tmp = Buffer.alloc(0)
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| 
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|   while (keyLen > 0 || ivLen > 0) {
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|     var hash = new MD5()
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|     hash.update(tmp)
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|     hash.update(password)
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|     if (salt) hash.update(salt)
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|     tmp = hash.digest()
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| 
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|     var used = 0
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| 
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|     if (keyLen > 0) {
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|       var keyStart = key.length - keyLen
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|       used = Math.min(keyLen, tmp.length)
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|       tmp.copy(key, keyStart, 0, used)
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|       keyLen -= used
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|     }
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| 
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|     if (used < tmp.length && ivLen > 0) {
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|       var ivStart = iv.length - ivLen
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|       var length = Math.min(ivLen, tmp.length - used)
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|       tmp.copy(iv, ivStart, used, used + length)
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|       ivLen -= length
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|     }
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|   }
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| 
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|   tmp.fill(0)
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|   return { key: key, iv: iv }
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| }
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| 
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| module.exports = EVP_BytesToKey
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