<%
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'FOR FILE TYPE 'UTF8'
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'Useage:
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'Dim cls
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'Set cls=new ClassBase64Encode
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'cls.Encode64("TargetString")
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'cls.Decode64("TargetString")
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'
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'
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Class ClassBase64Encode
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PRIVATE BASE_64_MAP_INIT
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PRIVATE newline
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PRIVATE Base64EncMap(63)
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PRIVATE Base64DecMap(127)
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Private Sub Class_Initialize
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call initCodecs
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End Sub
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PRIVATE SUB initCodecs()
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BASE_64_MAP_INIT = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
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newline = "<P>" & chr(13) & chr(10)
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dim max, idx
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max = len(BASE_64_MAP_INIT)
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for idx = 0 to max - 1
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Base64EncMap(idx) = mid(BASE_64_MAP_INIT, idx + 1, 1)
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next
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for idx = 0 to max - 1
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Base64DecMap(ASC(Base64EncMap(idx))) = idx
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next
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END SUB
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PRIVATE FUNCTION base64Encode(plain)
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if len(plain) = 0 then
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base64Encode = ""
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exit function
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end if
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dim ret, ndx, by3, first, second, third
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by3 = (len(plain) \ 3) * 3
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ndx = 1
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do while ndx <= by3
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first = asc(mid(plain, ndx+0, 1))
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second = asc(mid(plain, ndx+1, 1))
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third = asc(mid(plain, ndx+2, 1))
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ret = ret & Base64EncMap( (first \ 4) AND 63 )
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ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second \ 16) AND 15 ) )
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ret = ret & Base64EncMap( ((second * 4) AND 60) + ((third \ 64) AND 3 ) )
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ret = ret & Base64EncMap( third AND 63)
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ndx = ndx + 3
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loop
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if by3 < len(plain) then
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first = asc(mid(plain, ndx+0, 1))
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ret = ret & Base64EncMap( (first \ 4) AND 63 )
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if (len(plain) MOD 3 ) = 2 then
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second = asc(mid(plain, ndx+1, 1))
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ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second \ 16) AND 15 ) )
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ret = ret & Base64EncMap( ((second * 4) AND 60) )
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else
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ret = ret & Base64EncMap( (first * 16) AND 48)
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ret = ret '& "="
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end if
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ret = ret '& "="
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end if
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base64Encode = ret
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END FUNCTION
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PRIVATE FUNCTION base64Decode(scrambled)
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if len(scrambled) = 0 then
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base64Decode = ""
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exit function
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end if
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dim realLen
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realLen = len(scrambled)
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do while mid(scrambled, realLen, 1) = "="
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realLen = realLen - 1
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loop
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dim ret, ndx, by4, first, second, third, fourth
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ret = ""
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by4 = (realLen \ 4) * 4
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ndx = 1
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do while ndx <= by4
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first = Base64DecMap(asc(mid(scrambled, ndx+0, 1)))
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second = Base64DecMap(asc(mid(scrambled, ndx+1, 1)))
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third = Base64DecMap(asc(mid(scrambled, ndx+2, 1)))
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fourth = Base64DecMap(asc(mid(scrambled, ndx+3, 1)))
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ret = ret & chr( ((first * 4) AND 255) + ((second \ 16) AND 3))
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ret = ret & chr( ((second * 16) AND 255) + ((third \ 4) AND 15))
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ret = ret & chr( ((third * 64) AND 255) + (fourth AND 63))
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ndx = ndx + 4
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loop
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if ndx < realLen then
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first = Base64DecMap(asc(mid(scrambled, ndx+0, 1)))
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second = Base64DecMap(asc(mid(scrambled, ndx+1, 1)))
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ret = ret & chr( ((first * 4) AND 255) + ((second \ 16) AND 3))
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if realLen MOD 4 = 3 then
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third = Base64DecMap(asc(mid(scrambled,ndx+2,1)))
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ret = ret & chr( ((second * 16) AND 255) + ((third \ 4) AND 15))
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end if
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end if
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base64Decode = ret
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END FUNCTION
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Public Function Encode64(byval Str)
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Encode64 =base64Encode(STR)
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End Function
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Public Function Decode64(byval Str)
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Decode64 = base64Decode(STR)
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End Function
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End Class
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%>
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