Base58Check encoding

From Rosetta Code


The popular encoding of small and medium-sized checksums is base16, that is more compact than usual base10 and is human readable... For checksums resulting in hash digests bigger than ~100 bits, the base16 is too long: base58 is shorter and (when using good alphabet) preserves secure human readability. The most popular alphabet of base58 is the variant used in bitcoin address (see Bitcoin/address validation), so it is the "default base58 alphabet".

Write a program that takes a checksum (resultant hash digest) integer binary representation as argument, and converts (encode it) into base58 with the standard Bitcoin alphabet — which uses an alphabet of the characters 0 .. 9, A ..Z, a .. z, but without the four characters 0, O, I and l.

The reference algorithm is at the Bitcoin's Base58Check page.

FreeBASIC[edit]

Library: GMP
' version 14-08-2017
' compile with: fbc -s console
' uses GMP
 
#Include Once "gmp.bi"
 
Data "25420294593250030202636073700053352635053786165627414518" ' 6UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM
Data "0x61" ' 2g
Data "0x626262" ' a3gV
Data "0x636363" ' aPEr
Data "0x73696d706c792061206c6f6e6720737472696e67" ' 2cFupjhnEsSn59qHXstmK2ffpLv2
Data "0x516b6fcd0f" ' ABnLTmg
Data "0xbf4f89001e670274dd" ' 3SEo3LWLoPntC
Data "0x572e4794" ' 3EFU7m
Data "0xecac89cad93923c02321" ' EJDM8drfXA6uyA
Data "0x10c8511e" ' Rt5zm
Data ""
 
Function conv2base58(decimal As String, _base_ As Integer = 0) As String
 
Dim As String convert
Dim As String base58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
Dim As String norm58 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuv"
Dim As ZString Ptr gmp_str : gmp_str = Allocate(1000)
Dim As Mpz_ptr tmp = Allocate(Len(__mpz_struct)) : Mpz_init(tmp)
 
Mpz_set_str(tmp, decimal, _base_)
Mpz_get_str(gmp_str, 58, tmp)
 
convert = *gmp_str
 
For i As uinteger = 0 To Len(convert) -1
convert[i] = base58[InStr(norm58, Chr(convert[i])) -1]
Next
 
Mpz_clear(tmp) : DeAllocate(gmp_str)
 
Return convert
 
End Function
 
' ------=< MAIN >=------
Dim As String str_in
 
Print "OkobppXBkab(58) --> "; conv2base58("OkobppXBkab", 58) ' 10687460092462769069(10)
Print
 
Do
Read str_in
If str_in = "" Then Exit Do
Print str_in;
If Len(str_in) < 54 Then Print Tab(43);
Print " --> "; conv2base58(str_in)
Loop
 
' empty keyboard buffer
While Inkey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End
Output:
OkobppXBkab(58) --> RosettaCode

25420294593250030202636073700053352635053786165627414518 --> 6UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM
0x61                                       --> 2g
0x626262                                   --> a3gV
0x636363                                   --> aPEr
0x73696d706c792061206c6f6e6720737472696e67 --> 2cFupjhnEsSn59qHXstmK2ffpLv2
0x516b6fcd0f                               --> ABnLTmg
0xbf4f89001e670274dd                       --> 3SEo3LWLoPntC
0x572e4794                                 --> 3EFU7m
0xecac89cad93923c02321                     --> EJDM8drfXA6uyA
0x10c8511e                                 --> Rt5zm

Haskell[edit]

import Numeric (showIntAtBase)
 
chars = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
 
base58Encode :: Integer -> String
base58Encode n = showIntAtBase 58 (chars !!) n ""
 
main :: IO ()
main = mapM_ (putStrLn . base58Encode)
[25420294593250030202636073700053352635053786165627414518,
0x61,
0x626262,
0x636363,
0x73696d706c792061206c6f6e6720737472696e67,
0x516b6fcd0f,
0xbf4f89001e670274dd,
0x572e4794,
0xecac89cad93923c02321,
0x10c8511e]
Output:
6UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM
2g
a3gV
aPEr
2cFupjhnEsSn59qHXstmK2ffpLv2
ABnLTmg
3SEo3LWLoPntC
3EFU7m
EJDM8drfXA6uyA
Rt5zm

and for bulk encoding, Array access would be one of various slightly faster alternatives to recursive subscripting of linked lists:

import Numeric (showIntAtBase)
import Data.Array
 
base58Codes :: (Num i, Ix i) => Array i Char
base58Codes =
listArray (0, 57) "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
 
base58Encode :: (Show a, Integral a) => a -> String
base58Encode n = showIntAtBase 58 (base58Codes !) n ""
 
main :: IO ()
main =
mapM_
(putStrLn . base58Encode)
[ 25420294593250030202636073700053352635053786165627414518
, 0x61
, 0x626262
, 0x636363
, 0x73696d706c792061206c6f6e6720737472696e67
, 0x516b6fcd0f
, 0xbf4f89001e670274dd
, 0x572e4794
, 0xecac89cad93923c02321
, 0x10c8511e
]
Output:
6UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM
2g
a3gV
aPEr
2cFupjhnEsSn59qHXstmK2ffpLv2
ABnLTmg
3SEo3LWLoPntC
3EFU7m
EJDM8drfXA6uyA
Rt5zm

Perl 6[edit]

sub encode_Base58 ( Int $x ) {
constant @codes = <
1 2 3 4 5 6 7 8 9
A B C D E F G H J K L M N P Q R S T U V W X Y Z
a b c d e f g h i j k m n o p q r s t u v w x y z
>;
 
return @codes[ $x.polymod( 58 xx * ) ].join.flip;
}
 
my @tests =
25420294593250030202636073700053352635053786165627414518 => '6UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM',
0x61 => '2g',
0x626262 => 'a3gV',
0x636363 => 'aPEr',
0x73696d706c792061206c6f6e6720737472696e67 => '2cFupjhnEsSn59qHXstmK2ffpLv2',
0x516b6fcd0f => 'ABnLTmg',
0xbf4f89001e670274dd => '3SEo3LWLoPntC',
0x572e4794 => '3EFU7m',
0xecac89cad93923c02321 => 'EJDM8drfXA6uyA',
0x10c8511e => 'Rt5zm',
;
use Test;
for @tests {
is encode_Base58(.key), .value, "{.key} encodes to {.value}";
}
 

REXX[edit]

version 1[edit]

Following the description in https://www.anintegratedworld.com/how-to-manually-calculate-base58check-encoding/ I get the result expected there. Apart for the leading 1 the program works also for the inputs shown above.

/* REXX */
s="123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
Numeric Digits 100
k='00010966776006953D5567439E5E39F86A0D273BEED61967F6'x
n=c2d(k)
o=''
Do Until n=0
rem=n//58
n=n%58
o=o||substr(s,rem+1,1)
End
o=o||substr(s,1,1)
Say reverse(o)
Output:
16UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM

version 2[edit]

does what the others do

/* REXX */
s="123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
Numeric Digits 1000
cnt_ok=0
Call test 'N',25420294593250030202636073700053352635053786165627414518,,
'6UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM'
Call test 'X','61'x ,'2g'
Call test 'X','626262'x ,'a3gV'
Call test 'X','636363'x ,'aPEr'
Call test 'X','73696d706c792061206c6f6e6720737472696e67'x,,
'2cFupjhnEsSn59qHXstmK2ffpLv2'
Call test 'X','516b6fcd0f'x ,'ABnLTmg'
Call test 'X','bf4f89001e670274dd'x ,'3SEo3LWLoPntC'
Call test 'X','572e4794'x ,'3EFU7m'
Call test 'X','ecac89cad93923c02321'x ,'EJDM8drfXA6uyA'
Call test 'X','10c8511e'x ,'Rt5zm'
Call test 'X','10c8511e'x ,'check_error_handlimng'
Say cnt_ok 'tests ok'
Exit
test:
Parse Arg how,k,res
If how='X' Then
k=c2d(k)
o=''
Do Until k=0
rem=k//58
k=k%58
o=o||substr(s,rem+1,1)
End
o=reverse(o)
If o=res Then cnt_ok+=1
Else Do
Say 'expected:' res
Say 'found  :' o
End
Return
Output:
expected: check_error_handlimng
found   : Rt5zm
10 tests ok