AutoHotkey Community

In =
( Join
Man is distinguished, not only by his reason, but by this singular passion from other animals,
 which is a lust of the mind, that by a perseverance of delight in the continued and
 indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.
)
Out =
( Join
TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0
aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1
c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0
aGUgY29udGludWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdl
LCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=
)

StringCaseSense On
Chars = ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/

If Base64(In) = Out
   MsgBox OK
If InvBase64(Out) = In
   MsgBox OK

Base64(string)
{
   Loop Parse, string
   {
      If Mod(A_Index,3) = 1
         buffer := Asc(A_LoopField) << 16
      Else If Mod(A_Index,3) = 2
         buffer += Asc(A_LoopField) << 8
      Else {
         buffer += Asc(A_LoopField)
         out := out . Code(buffer>>18) . Code(buffer>>12) . Code(buffer>>6) . Code(buffer)
      }
   }
   If Mod(StrLen(string),3) = 0
      Return out
   If Mod(StrLen(string),3) = 1
      Return out . Code(buffer>>18) . Code(buffer>>12) "=="
   Return out . Code(buffer>>18) . Code(buffer>>12) . Code(buffer>>6) "="
}

InvBase64(code)
{
   StringReplace code, code, =,,All
   Loop Parse, code
   {
      If Mod(A_Index,4) = 1
         buffer := DeCode(A_LoopField) << 18
      Else If Mod(A_Index,4) = 2
         buffer += DeCode(A_LoopField) << 12
      Else If Mod(A_Index,4) = 3
         buffer += DeCode(A_LoopField) << 6
      Else {
         buffer += DeCode(A_LoopField)
         out := out . Chr(buffer>>16) . Chr(255 & buffer>>8) . Chr(255 & buffer)
      }
   }
   If Mod(StrLen(code),4) = 0
      Return out
   If Mod(StrLen(code),4) = 2
      Return out . Chr(buffer>>16)
   Return out . Chr(buffer>>16) . Chr(255 & buffer>>8)
}

Code(i)     ; <== Chars[i & 63], 0-base index
{
   Global Chars
   StringMid i, Chars, (i&63)+1, 1
   Return i
}

DeCode(c)   ; c = a char in Chars ==> position [0,63]
{
   Global Chars
   Return InStr(Chars,c,1) - 1
}

Base64Encode(ByRef bin, n=0) {
   m := VarSetCapacity(bin)
   If n not between 1 and %m%
      n = %m%
   Loop %n% {
      A := *(&bin+A_Index-1)
      m := Mod(A_Index,3)
      IfEqual      m,1, SetEnv buffer,% A << 16
      Else IfEqual m,2, EnvAdd buffer,% A << 8
      Else {
         buffer += A
         out := out Code(buffer>>18) Code(buffer>>12) Code(buffer>>6) Code(buffer)
      }
   }
   IfEqual m,0, Return out
   IfEqual m,1, Return out Code(buffer>>18) Code(buffer>>12) "=="
   Return out Code(buffer>>18) Code(buffer>>12) Code(buffer>>6) "="
}

Base64Decode(ByRef bin, code) {
   StringReplace code, code, =,,All
   VarSetCapacity(bin, 3*StrLen(code)//4, 0)
   Loop Parse, code
   {
      m := A_Index & 3 ; mod 4
      IfEqual m,0, {
         buffer += DeCode(A_LoopField)
         Append(bin, pos, buffer>>16, 255 & buffer>>8, 255 & buffer)
      }
      Else IfEqual m,1, SetEnv buffer, % DeCode(A_LoopField) << 18
      Else buffer += DeCode(A_LoopField) << 24-6*m
   }
   IfEqual m,0, Return
   IfEqual m,2
        Append(bin, pos, buffer>>16)
   Else Append(bin, pos, buffer>>16, 255 & buffer>>8)
}

Append(ByRef bin, ByRef pos, c1, c2="", c3="", c4="") {
   pos += 0
   Loop 4 {
      IfEqual c%A_Index%,, Break
      DllCall("RtlFillMemory",UInt,&bin+pos, UInt,1, UChar,c%A_Index%)
      pos++
   }
}

Code(i) {   ; <== Chars[i & 63], 0-base index
   Global Chars
   StringMid i, Chars, (i&63)+1, 1
   Return i
}

DeCode(c) { ; c = a char in Chars ==> position [0,63]
   Global Chars
   Return InStr(Chars,c,1) - 1
}

A = 123-aB. ; TEST
Loop 8 {
    C := Base64Encode(A,A_Index)
    Base64Decode(D,C)
    VarSetCapacity(D,-1) ; use when D is string (instead of taking binary info)
    MsgBox % SubStr(A,1,A_Index) "`n" C "`n" D
}

Base64Encode(ByRef bin, n=0) {
   m := VarSetCapacity(bin)
   Loop % n<1 || n>m ? m : n
      A := *(&bin+A_Index-1)
     ,m := Mod(A_Index,3)
     ,b := m=1 ? A << 16 : m=2 ? b+(A<<8) : b+A
     ,out .= m ? "" : Code(b>>18) Code(b>>12) Code(b>>6) Code(b)
   Return out (m ? Code(b>>18) Code(b>>12) (m=1 ? "==" : Code(b>>6) "=") : "")
}
Code(i) {   ; <== Chars[i & 63], 0-base index
   Static Chars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
   Return SubStr(Chars,(i&63)+1,1)
}

Base64Decode(ByRef bin, code) {
   Static Chars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
   StringReplace code, code, =,, All
   VarSetCapacity(bin, 3*StrLen(code)//4, 0)
   pos = 0
   Loop Parse, code
      m := A_Index&3, d := InStr(Chars,A_LoopField,1) - 1
     ,b := m ? (m=1 ? d<<18 : b+(d<<24-6*m)) : b+d
     ,Append(bin, pos, 3*!m, b>>16, 255 & b>>8, 255 & b)
   Append(bin, pos, !!m+(m&1), b>>16, 255 & b>>8, 0)
}
Append(ByRef bin, ByRef pos, k, c1,c2,c3) {
   Loop %k%
      DllCall("RtlFillMemory",UInt,&bin+pos++, UInt,1, UChar,c%A_Index%)
}

In =
( Join
Man is distinguished, not only by his reason, but by this singular passion from other animals
, which is a lust of the mind, that by a perseverance of delight in the continued
, and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.
)

example := "Ascii85: -----`n" . Ascii85(In)
   . "`n`nInverse: -----`n" . Ascii85(Ascii85(In), 1)
MsgBox, 64, Ascii85, %example%
ExitApp

Ascii85(str, inv=0) { ; by Titan
   xFI := A_FormatInteger
   If inv {
      StringReplace, str, str, <~
      StringReplace, str, str, ~>
      Loop, Parse, str
         If !Mod(A_Index, 5) or StrLen(str) / A_Index = 1 {
            If StrLen(str) / A_Index = 1
               tr := 5 - Mod(A_Index, 5)
            Loop, %tr%
               x += (Asc("0x00") - 33) * (85 ** 5 - (5 - (5 - Mod(A_Index, 5))))
            x += Asc(A_LoopField) - 33
            SetFormat, Integer, Hex
            x += 0
            Loop, 4 {
               StringMid, a, x, (A_Index * 2) + 1, 2
               i := i . Chr("0x" . a)
            } SetFormat, Integer, D
            x = 0
         } Else x += (Asc(A_LoopField) - 33) * (85 ** (5 - Mod(A_Index, 5)))
      StringTrimRight, i, i, %tr%
      Return, i
   } SetFormat, Integer, Hex
   Loop, Parse, str
      If !Mod(A_Index, 4) or (StrLen(str) / A_Index = 1) {
         x := x . Asc(A_LoopField)
         If StrLen(str) / A_Index = 1 and Mod(A_Index, 4)
            tr := 4 - Mod(A_Index, 4)
         Loop, %tr%
            x := x . 0x00
         StringReplace, x, x, 0x, , 1
         x =0x%x%
         SetFormat, Integer, D
         x += 0
         Loop, 5
            i := i . Chr((Floor(Mod(x / (85 ** (5 - A_Index)), 85))) + 33)
         SetFormat, Integer, Hex
         StringTrimLeft, x, x, 4
         x := ""
      } Else x := x . Asc(A_LoopField)
   StringReplace, i, i, !!!!!, z, 1
   StringTrimRight, i, i, %tr%
   SetFormat, Integer, %xFI%
   Return, "<~" . i . "~>"
}

In =
( Join
Man is distinguished, not only by his reason, but by this singular passion from other animals,
 which is a lust of the mind, that by a perseverance of delight in the continued and
 indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.
)
Out =
( Join
TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0
aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1
c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0
aGUgY29udGludWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdl
LCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=
)

StringCaseSense On
Chars = ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/

MsgBox % "Encode = " (Base64Encode(In) == Out)
MsgBox % "Decode = " (Base64Decode(Out) == In)

Base64Encode(string) {
   Loop Parse, string
   {
      m := Mod(A_Index,3)
      IfEqual      m,1, SetEnv buffer, % Asc(A_LoopField) << 16
      Else IfEqual m,2, EnvAdd buffer, % Asc(A_LoopField) << 8
      Else {
         buffer += Asc(A_LoopField)
         out := out Code(buffer>>18) Code(buffer>>12) Code(buffer>>6) Code(buffer)
      }
   }
   IfEqual m,0, Return out
   IfEqual m,1, Return out Code(buffer>>18) Code(buffer>>12) "=="
   Return out Code(buffer>>18) Code(buffer>>12) Code(buffer>>6) "="
}

Base64Decode(code) {
   StringReplace code, code, =,,All
   Loop Parse, code
   {
      m := A_Index & 3 ; mod 4
      IfEqual m,0, {
         buffer += DeCode(A_LoopField)
         out := out Chr(buffer>>16) Chr(255 & buffer>>8) Chr(255 & buffer)
      }
      Else IfEqual m,1, SetEnv buffer, % DeCode(A_LoopField) << 18
      Else buffer += DeCode(A_LoopField) << 24-6*m
   }
   IfEqual m,0, Return out
   IfEqual m,2, Return out Chr(buffer>>16)
   Return out Chr(buffer>>16) Chr(255 & buffer>>8)
}

Code(i) {   ; <== Chars[i & 63], 0-base index
   Global Chars
   StringMid i, Chars, (i&63)+1, 1
   Return i
}

DeCode(c) { ; c = a char in Chars ==> position [0,63]
   Global Chars
   Return InStr(Chars,c,1) - 1
}