Bitcoin/address validation: Difference between revisions

(→‎{{header|PicoLisp}}: wrong, reimplement)
Line 971:
(valid "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62iz")
(valid "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62izz") ) )</lang>
 
=={{header|PureBasic}}==
<lang PureBasic>
; using PureBasic 5.50 (x64)
EnableExplicit
 
Macro IsValid(expression)
If expression
PrintN("Valid")
Else
PrintN("Invalid")
EndIf
EndMacro
 
Procedure.i DecodeBase58(Address$, Array result.a(1))
Protected i, j, p
Protected charSet$ = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
Protected c$
For i = 1 To Len(Address$)
c$ = Mid(Address$, i, 1)
p = FindString(charSet$, c$) - 1
If p = -1 : ProcedureReturn #False : EndIf; Address contains invalid Base58 character
For j = 24 To 1 Step -1
p + 58 * result(j)
result(j) = p % 256
p / 256
Next j
If p <> 0 : ProcedureReturn #False : EndIf ; Address is too long
Next i
ProcedureReturn #True
EndProcedure
 
Procedure HexToBytes(hex$, Array result.a(1))
Protected i
For i = 1 To Len(hex$) - 1 Step 2
result(i/2) = Val("$" + Mid(hex$, i, 2))
Next
EndProcedure
 
Procedure.i IsBitcoinAddressValid(Address$)
Protected format$, digest$
Protected i, isValid
Protected Dim result.a(24)
Protected Dim result2.a(31)
Protected result$, result2$
; Address length must be between 26 and 35 - see 'https://en.bitcoin.it/wiki/Address'
If Len(Address$) < 26 Or Len(Address$) > 35 : ProcedureReturn #False : EndIf
; and begin with either 1 or 3 which is the format number
format$ = Left(Address$, 1)
If format$ <> "1" And format$ <> "3" : ProcedureReturn #False : EndIf
isValid = DecodeBase58(Address$, result())
If Not isValid : ProcedureReturn #False : EndIf
UseSHA2Fingerprint(); Using functions from PB's built-in Cipher library
digest$ = Fingerprint(@result(), 21, #PB_Cipher_SHA2, 256); apply SHA2-256 to first 21 bytes
HexToBytes(digest$, result2()); change hex string to ascii array
digest$ = Fingerprint(@result2(), 32, #PB_Cipher_SHA2, 256); apply SHA2-256 again to all 32 bytes
HexToBytes(digest$, result2())
result$ = PeekS(@result() + 21, 4, #PB_Ascii); last 4 bytes
result2$ = PeekS(@result2(), 4, #PB_Ascii); first 4 bytes
If result$ <> result2$ : ProcedureReturn #False : EndIf
ProcedureReturn #True
EndProcedure
 
If OpenConsole()
Define address$ = "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i"
Define address2$ = "1BGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i"
Define address3$ = "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62I"
Print(address$ + " -> ")
IsValid(IsBitcoinAddressValid(address$))
Print(address2$ + " -> ")
IsValid(IsBitcoinAddressValid(address2$))
Print(address3$ + " -> ")
IsValid(IsBitcoinAddressValid(address3$))
PrintN("")
PrintN("Press any key to close the console")
Repeat: Delay(10) : Until Inkey() <> ""
CloseConsole()
EndIf
 
</lang>
 
{{out}}
<pre>
1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i -> Valid
1BGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i -> Invalid
1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62I -> Invalid
</pre>
 
=={{header|Python}}==
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