52 lines
1.9 KiB
Plaintext
52 lines
1.9 KiB
Plaintext
type Chaocipher:Mode
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enum
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int ENCRYPT, DECRYPT
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end
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type Chaocipher
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text L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
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text R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC"
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fun exec = text by text value, Chaocipher:Mode mode, logic showSteps
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^|since texts are mutable, we can operate directly on them without the need of Lists|^
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text left = *L_ALPHABET # by using the valueOf operator we are sure that the string is copied
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text right = *R_ALPHABET
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text eText = text(" ", value.length)
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text temp = text(" ", 26)
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for int i = 0; i < value.length; ++i
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if showSteps do writeLine(left + " " + right) end
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int index = 0
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if mode == Chaocipher:Mode.ENCRYPT
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index = right.find(value[i])
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eText[i] = left[index]
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else
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index = left.find(value[i])
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eText[i] = right[index]
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end
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if i == value.length - 1 do break end
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# permute left
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for int j = index; j < 26; ++j do temp[j - index] = left[j] end
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for int j = 0; j < index; ++j do temp[26 - index + j] = left[j] end
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var store = temp[1]
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for int j = 2; j < 14; ++j do temp[j - 1] = temp[j] end
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temp[13] = store
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left = *temp
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# permute right
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for int j = index; j < 26; ++j do temp[j - index] = right[j] end
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for int j = 0; j < index; ++j do temp[26 - index + j] = right[j] end
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store = temp[0]
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for int j = 1; j < 26; ++j do temp[j - 1] = temp[j] end
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temp[25] = store
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store = temp[2]
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for int j = 3; j < 14; ++j do temp[j - 1] = temp[j] end
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temp[13] = store
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right = *temp
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end
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return eText
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end
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var plainText = "WELLDONEISBETTERTHANWELLSAID"
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writeLine("The original plaintext is : " + plainText)
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writeLine(EOL + "The left and right alphabets after each permutation during encryption are :" + EOL)
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var cipherText = exec(plainText, Chaocipher:Mode.ENCRYPT, true)
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writeLine(EOL + "The ciphertext is : " + cipherText)
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var plainText2 = exec(cipherText, Chaocipher:Mode.DECRYPT, false)
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writeLine(EOL + "The recovered plaintext is : " + plainText2)
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