Rosetta Code

The ISAAC cipher: Difference between revisions

Page Discussion

The ISAAC cipher (view source)

Revision as of 11:57, 14 February 2024

77 bytes added ,  3 months ago
m
→‎{{header|Wren}}: Minor tidy
m (→‎{{header|Wren}}: Wren-trait -> Wren-iterate)
m (→‎{{header|Wren}}: Minor tidy)
 
(3 intermediate revisions by 2 users not shown)
Line 59:
But building a strong and simple ISAAC-based stream cipher - replacing the irreparably broken RC4 - is our goal here: ISAAC's intended purpose.
<br><br>
 
=={{header|BASIC}}==
==={{header|FreeBASIC}}===
{{trans|C}}
<syntaxhighlight lang="freebasic">' version 03-11-2016
' compile with: fbc -s console
 
Dim Shared As UInteger<32> randrsl(256), randcnt
Static Shared As UInteger<32> mm(256)
Static Shared As UInteger<32> aa, bb ,cc
 
Sub ISAAC()
Dim As UInteger<32> i, x, y
cc = cc + 1
bb = bb + cc
For i = 0 To 256 -1
x = mm(i)
Select Case (i Mod 4)
Case 0 : aa = aa Xor (aa Shl 13)
Case 1 : aa = aa Xor (aa Shr 6)
Case 2 : aa = aa Xor (aa Shl 2)
Case 3 : aa = aa Xor (aa Shr 16)
End Select
aa = mm((i+128) Mod 256) + aa
y = mm((x Shr 2) Mod 256) + aa + bb : mm(i) = y
bb = mm((y Shr 10) Mod 256) + x : randrsl(i) = bb
Next
randcnt = 0
End Sub
 
#Macro mix(a, b, c, d, e, f, g, h)
a Xor= b Shl 11 : d += a : b += c
b Xor= c Shr 2 : e += b : c += d
c Xor= d Shl 8 : f += c : d += e
d Xor= e Shr 16 : g += d : e += f
e Xor= f Shl 10 : h += e : f += g
f Xor= g Shr 4 : a += f : g += h
g Xor= h Shl 8 : b += g : h += a
h Xor= a Shr 9 : c += h : a += b
#EndMacro
 
Sub randinit(flag As Long)
Dim As Long i
Dim As UInteger<32> a = &H9e3779b9 '/* the golden ratio *
Dim As UInteger<32> b = &H9e3779b9
Dim As UInteger<32> c = &H9e3779b9
Dim As UInteger<32> d = &H9e3779b9
Dim As UInteger<32> e = &H9e3779b9
Dim As UInteger<32> f = &H9e3779b9
Dim As UInteger<32> g = &H9e3779b9
Dim As UInteger<32> h = &H9e3779b9
aa = 0 : bb = 0 : cc = 0
For i = 0 To 3
mix(a, b, c, d, e, f, g, h)
Next
For i = 0 To 255 Step 8
If flag = 1 Then
a += randrsl(i ) : b += randrsl(i +1)
c += randrsl(i +2) : d += randrsl(i +3)
e += randrsl(i +4) : f += randrsl(i +5)
g += randrsl(i +6) : h += randrsl(i +7)
mix(a, b, c, d, e, f, g, h)
mm(i ) = a : mm(i +1) = b : mm(i +2) = c : mm(i +3) = d
mm(i +4) = e : mm(i +5) = f : mm(i +6) = g : mm(i +7) = h
End If
Next
If flag = 1 Then
For i = 0 To 255 Step 8
a += mm(i ) : b += mm(i +1)
c += mm(i +2) : d += mm(i +3)
e += mm(i +4) : f += mm(i +5)
g += mm(i +6) : h += mm(i +7)
mix(a, b, c, d, e, f, g, h)
mm(i )= a : mm(i +1) = b : mm(i +2) = c : mm(i +3) = d
mm(i +4)= e : mm(i +5) = f : mm(i +6) = g : mm(i +7) = h
Next
End If
ISAAC()
randcnt = 0
End Sub
 
' // Get a random 32-bit value 0..MAXINT
Function iRandom() As UInteger<32>
Dim As UInteger<32> r = randrsl(randcnt)
randcnt += 1
If randcnt > 255 Then
ISAAC()
randcnt = 0
End If
Return r
End Function
 
' // Get a random character in printable ASCII range
Function iRandA() As UByte
Return iRandom() Mod 95 +32
End Function
 
' // Seed ISAAC with a string
Sub iSeed(seed As String, flag As Long)
Dim As ULong i, m = Len(seed) -1
For i = 0 To 255
mm(i) = 0
Next
For i = 0 To 255
If i > m Then
randrsl(i) = 0
Else
randrsl(i) = seed[i]
End If
Next
randinit(flag)
End Sub
 
' // maximum length of message
'#define MAXMSG 4096
#Define _MOD_ 95 ' mod is FreeBASIC keyword
#Define _START_ 32 ' start is used as variable name
 
' // cipher modes for Caesar
Enum ciphermode
mEncipher
mDecipher
mNone
End Enum
 
' // XOR cipher on random stream. Output: ASCII string
' no maximum lenght for input and output string
Function Vernam(msg As String) As String
Dim As ULong i
Dim As String v
For i = 0 To Len(msg) -1
v += Chr(iRandA() Xor msg[i])
Next
Return v
End Function
 
' // Caesar-shift a printable character
Function Ceasar(m As ciphermode, ch As UByte, shift As UByte, modulo As UByte, _
start As UByte) As UByte
' FreeBASIC Mod does not handle negative numbers correctly
' also there is litte problem with shift (declared UByte)
' the IIF() statement helps with shift
' to avoid a negative n a 8 times modulo is added
' modulo * 8 get translateted by FreeBASIC to modulo shl 3
Dim As Long n = (ch - start) + IIf(m = mDecipher, -shift, shift) + modulo * 8
n = n Mod modulo
Return start + n
End Function
 
' // Caesar-shift a string on a pseudo-random stream
Function CeasarStr(m As ciphermode, msg As String, modulo As UByte, _
start As UByte) As String
Dim As Long i
Dim As String v
For i = 0 To Len(msg) -1
v += Chr(Ceasar(m, msg[i], iRandA(), modulo, start))
Next
Return v
End Function
 
' ------=< MAIN >=------
 
Dim As Long n, l
Dim As String msg = "a Top Secret secret"
Dim As String key = "this is my secret key"
 
Dim As String vctx, vptx
Dim As String cctx, cptx
 
l = Len(msg)
' // Encrypt: Vernam XOR
iSeed(key, 1)
vctx = Vernam(msg)
' // Encrypt: Caesar
cctx = CeasarStr(mEncipher, msg, _mod_, _start_)
' // Decrypt: Vernam XOR
iSeed(key, 1)
vptx = Vernam(vctx)
' // Decrypt: Caesar
cptx = CeasarStr(mDecipher, cctx, _mod_, _start_)
Print "message: "; msg
Print " key: "; key
Print " XOR: ";
' // Output Vernam ciphertext as a string of hex digits
For n = 0 To l -1
Print Hex(vctx[n], 2);
Next
Print
' // Output Vernam decrypted plaintext
Print "XOR dcr: "; vptx
' // Caesar
Print " MOD: ";
' // Output Caesar ciphertext as a string of hex digits
For n= 0 To l -1
Print Hex(cctx[n], 2);
Next
Print
' // Output Caesar decrypted plaintext
Print "MOD dcr: " ; cptx
 
' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End</syntaxhighlight>
{{out}}
<pre>message: a Top Secret secret
key: this is my secret key
XOR: 1C0636190B1260233B35125F1E1D0E2F4C5422
XOR dcr: a Top Secret secret
MOD: 734270227D36772A783B4F2A5F206266236978
MOD dcr: a Top Secret secret</pre>
 
=={{header|C}}==
Line 1,710 ⟶ 1,922:
Caesar decoded : a Top Secret secret ok
</pre>
=={{header|FreeBASIC}}==
{{trans|C}}
<syntaxhighlight lang="freebasic">' version 03-11-2016
' compile with: fbc -s console
 
Dim Shared As UInteger<32> randrsl(256), randcnt
Static Shared As UInteger<32> mm(256)
Static Shared As UInteger<32> aa, bb ,cc
 
Sub ISAAC()
 
Dim As UInteger<32> i, x, y
 
cc = cc + 1
bb = bb + cc
 
For i = 0 To 256 -1
x = mm(i)
Select Case (i Mod 4)
Case 0 : aa = aa Xor (aa Shl 13)
Case 1 : aa = aa Xor (aa Shr 6)
Case 2 : aa = aa Xor (aa Shl 2)
Case 3 : aa = aa Xor (aa Shr 16)
End Select
aa = mm((i+128) Mod 256) + aa
y = mm((x Shr 2) Mod 256) + aa + bb : mm(i) = y
bb = mm((y Shr 10) Mod 256) + x : randrsl(i) = bb
Next
 
randcnt = 0
 
End Sub
 
 
#Macro mix(a, b, c, d, e, f, g, h)
 
a Xor= b Shl 11 : d += a : b += c
b Xor= c Shr 2 : e += b : c += d
c Xor= d Shl 8 : f += c : d += e
d Xor= e Shr 16 : g += d : e += f
e Xor= f Shl 10 : h += e : f += g
f Xor= g Shr 4 : a += f : g += h
g Xor= h Shl 8 : b += g : h += a
h Xor= a Shr 9 : c += h : a += b
 
#EndMacro
 
Sub randinit(flag As Long)
 
Dim As Long i
Dim As UInteger<32> a = &H9e3779b9 '/* the golden ratio *
Dim As UInteger<32> b = &H9e3779b9
Dim As UInteger<32> c = &H9e3779b9
Dim As UInteger<32> d = &H9e3779b9
Dim As UInteger<32> e = &H9e3779b9
Dim As UInteger<32> f = &H9e3779b9
Dim As UInteger<32> g = &H9e3779b9
Dim As UInteger<32> h = &H9e3779b9
aa = 0 : bb = 0 : cc = 0
 
For i = 0 To 3
mix(a, b, c, d, e, f, g, h)
Next
 
For i = 0 To 255 Step 8
If flag = 1 Then
a += randrsl(i ) : b += randrsl(i +1)
c += randrsl(i +2) : d += randrsl(i +3)
e += randrsl(i +4) : f += randrsl(i +5)
g += randrsl(i +6) : h += randrsl(i +7)
 
mix(a, b, c, d, e, f, g, h)
mm(i ) = a : mm(i +1) = b : mm(i +2) = c : mm(i +3) = d
mm(i +4) = e : mm(i +5) = f : mm(i +6) = g : mm(i +7) = h
End If
Next
 
If flag = 1 Then
For i = 0 To 255 Step 8
a += mm(i ) : b += mm(i +1)
c += mm(i +2) : d += mm(i +3)
e += mm(i +4) : f += mm(i +5)
g += mm(i +6) : h += mm(i +7)
 
mix(a, b, c, d, e, f, g, h)
mm(i )= a : mm(i +1) = b : mm(i +2) = c : mm(i +3) = d
mm(i +4)= e : mm(i +5) = f : mm(i +6) = g : mm(i +7) = h
Next
End If
 
ISAAC()
randcnt = 0
 
End Sub
 
' // Get a random 32-bit value 0..MAXINT
Function iRandom() As UInteger<32>
 
Dim As UInteger<32> r = randrsl(randcnt)
randcnt += 1
If randcnt > 255 Then
ISAAC()
randcnt = 0
End If
 
Return r
 
End Function
 
' // Get a random character in printable ASCII range
Function iRandA() As UByte
 
Return iRandom() Mod 95 +32
 
End Function
 
' // Seed ISAAC with a string
Sub iSeed(seed As String, flag As Long)
 
Dim As ULong i, m = Len(seed) -1
 
For i = 0 To 255
mm(i) = 0
Next
 
For i = 0 To 255
 
If i > m Then
randrsl(i) = 0
Else
randrsl(i) = seed[i]
End If
 
Next
 
randinit(flag)
 
End Sub
 
' // maximum length of message
'#define MAXMSG 4096
#Define _MOD_ 95 ' mod is FreeBASIC keyword
#Define _START_ 32 ' start is used as variable name
 
' // cipher modes for Caesar
Enum ciphermode
mEncipher
mDecipher
mNone
End Enum
 
' // XOR cipher on random stream. Output: ASCII string
' no maximum lenght for input and output string
Function Vernam(msg As String) As String
 
Dim As ULong i
Dim As String v
 
For i = 0 To Len(msg) -1
v += Chr(iRandA() Xor msg[i])
Next
 
Return v
 
End Function
 
' // Caesar-shift a printable character
Function Ceasar(m As ciphermode, ch As UByte, shift As UByte, modulo As UByte, _
start As UByte) As UByte
 
' FreeBASIC Mod does not handle negative numbers correctly
' also there is litte problem with shift (declared UByte)
' the IIF() statement helps with shift
' to avoid a negative n a 8 times modulo is added
' modulo * 8 get translateted by FreeBASIC to modulo shl 3
Dim As Long n = (ch - start) + IIf(m = mDecipher, -shift, shift) + modulo * 8
n = n Mod modulo
Return start + n
 
End Function
 
' // Caesar-shift a string on a pseudo-random stream
Function CeasarStr(m As ciphermode, msg As String, modulo As UByte, _
start As UByte) As String
 
Dim As Long i
Dim As String v
 
For i = 0 To Len(msg) -1
v += Chr(Ceasar(m, msg[i], iRandA(), modulo, start))
Next
 
Return v
 
End Function
 
' ------=< MAIN >=------
 
Dim As Long n, l
Dim As String msg = "a Top Secret secret"
Dim As String key = "this is my secret key"
 
Dim As String vctx, vptx
Dim As String cctx, cptx
 
l = Len(msg)
' // Encrypt: Vernam XOR
iSeed(key, 1)
vctx = Vernam(msg)
' // Encrypt: Caesar
cctx = CeasarStr(mEncipher, msg, _mod_, _start_)
' // Decrypt: Vernam XOR
iSeed(key, 1)
vptx = Vernam(vctx)
' // Decrypt: Caesar
cptx = CeasarStr(mDecipher, cctx, _mod_, _start_)
Print "message: "; msg
Print " key: "; key
Print " XOR: ";
' // Output Vernam ciphertext as a string of hex digits
For n = 0 To l -1
Print Hex(vctx[n], 2);
Next
Print
' // Output Vernam decrypted plaintext
Print "XOR dcr: "; vptx
' // Caesar
Print " MOD: ";
' // Output Caesar ciphertext as a string of hex digits
For n= 0 To l -1
Print Hex(cctx[n], 2);
Next
Print
' // Output Caesar decrypted plaintext
Print "MOD dcr: " ; cptx
 
' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End</syntaxhighlight>
{{out}}
<pre>message: a Top Secret secret
key: this is my secret key
XOR: 1C0636190B1260233B35125F1E1D0E2F4C5422
XOR dcr: a Top Secret secret
MOD: 734270227D36772A783B4F2A5F206266236978
MOD dcr: a Top Secret secret</pre>
 
=={{header|Go}}==
Line 3,308 ⟶ 3,272:
TMode = (iEncrypt, iDecrypt);
TString = ARRAY [0 .. MaxStrLength - 1] OF CHAR;
THexString = ARRAY [0 .. 2 * MaxStrLength - 1] OF CHAR;
TCardIndexedFrom0To7 = ARRAY [0 .. 7] OF CARDINAL;
 
Line 3,318 ⟶ 3,283:
XorPlainText: TString = '';
ModPlainText: TString = '';
HexText: THexString;
Mode: TMode = iEncrypt;
HexText: TString;
 
(* ISAAC globals *)
(* external results *)
RandRsl: ARRAY [0 .. 256255] OF CARDINAL;
RandCnt: CARDINAL;
 
(* internal state *)
MM: ARRAY [0 .. 256255] OF CARDINAL;
AA: CARDINAL = 0;
BB: CARDINAL = 0;
Line 3,414 ⟶ 3,378:
PROCEDURE SeedIsaac(Seed: ARRAY OF CHAR; Flag: BOOLEAN);
VAR
I, MSeedLength: CARDINAL;
BEGIN
FOR I := 0 TO 255 DO
MM[I] := 0;
END;
MSeedLength := Length(Seed);
FOR I := 0 TO 255 DO
(* In case seed has less than 256 elements *)
IF I > MSeedLength THEN
RandRsl[I] := 0
ELSE
Line 3,475 ⟶ 3,439:
OrdMsgI: SHORTCARD;
BEGIN
Assign(''Msg, Destination);
FOR I := 0 TO Length(Msg) - 1 DO
OrdMsgI := ORD(Msg[I]);
Append(Destination[I] := CHR(GetRandomChar() BXOR OrdMsgI), Destination);
END;
END Vernam;
Line 3,511 ⟶ 3,475:
I: CARDINAL;
BEGIN
Assign(''Msg, Destination);
FOR I := 0 TO Length(Msg) - 1 DO
Append(Destination[I] := Caesar(M, Msg[I], GetRandomChar(), 95, ' '), Destination);
END;
END Vigenere;
Line 3,521 ⟶ 3,485:
SeedIsaac(Key, TRUE);
(* (2) Encryption *)
Mode := iEncrypt;
(* (a) XOR (Vernam) *)
Vernam(Msg, XorCipherText);
(* (b) MOD (Vigenere) *)
Vigenere(Msg, ModeiEncrypt, ModCipherText);
(* (3) Decryption *)
Mode := iDecrypt;
SeedIsaac(Key, TRUE);
(* (a) XOR (Vernam) *)
Vernam(XorCipherText, XorPlainText);
(* (b) MOD (Vigenere) *)
Vigenere(ModCipherText, ModeiDecrypt, ModPlainText);
(* program output *)
WriteString('Message: '); WriteString(Msg); WriteLn;
Line 3,557 ⟶ 3,519:
{{trans|Pascal}}
We choose the translate the Pascal version as the it’s easier to translate to Nim from Pascal rather than from C.
This is not an exact transationtranslation: the more important difference is the use of a global state record rather than a list of global variables. This global state is transmitted to each procedure. This way, it is possible to run several PRNG concurrently.
 
We have also replaced the eight variables "a" to "h" with an array. This allows to simplify the code at several places by using a loop. And we changed the "mod" to "and", even if the compiler will likely optimize the modulo when the second operand is a power of two.
 
Note that the "mix" procedure could possibly be transformed in a template or be marked as "inline" (in the C version, it is a "define"). But as we are not in a procedure whose performance is critical, expanding the code rather than calling a procedure is not very useful.
 
<syntaxhighlight lang="nim">import strutils
Line 5,708 ⟶ 5,670:
{{libheader|Wren-dynamic}}
{{libheader|Wren-fmt}}
<syntaxhighlight lang="ecmascriptwren">import "./iterate" for Stepped
import "./dynamic" for Enum
import "./fmt" for Fmt
 
/* external results */
PureFox
9,476

edits

Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/337879...352517"