Time-based one-time password algorithm: Difference between revisions
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{{wikipedia}}
A Time-based One-time Password Algorithm (TOTP) is an algorithm that computes a one-time password from a shared secret key and the current time. It is the cornerstone of [[wp:Initiative_For_Open_Authentication|Initiative For Open Authentication (OATH)]] and is used in a number of two factor authentication systems.
Essentially, both the server and the client compute the time-limited token, then the server checks if the token supplied by the client matches the locally generated token.
;Task:
Implement this algorithm using '''HMAC-SHA1''' and an optional step is to generate the random [[wp:Base32|Base-32]] string used as the secret key, but this is not a requirement.
A reference implementation, based on JavaScript, can be found at the following location:
::: [http://blog.tinisles.com/2011/10/google-authenticator-one-time-password-algorithm-in-javascript http://blog.tinisles.com/2011/10/google-authenticator-one-time-password-algorithm-in-javascript]
According to RFC 6238, the reference implementation is as follows:
* Generate a key, '''K''', which is an arbitrary bytestring, and share it securely with the client.
* Agree upon an epoch, T0, and an interval, TI, which will be used to calculate the value of the counter C (defaults are the Unix epoch as T0 and 30 seconds as TI)
* Agree upon a cryptographic hash method (default is SHA-1)
* Agree upon a token length, '''N''' (default is 6)
Although RFC 6238 allows different parameters to be used, the Google implementation of the authenticator app does not support T0, TI values, hash methods and token lengths different from the default. It also expects the '''K''' secret key to be entered (or supplied in a QR code) in base-32 encoding according to RFC 3548.
* [
* [https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2 Google Authenticator App (Google Android)]
* [http://www.windowsphone.com/en-us/store/app/authenticator/e7994dbc-2336-4950-91ba-ca22d653759b Microsoft Authenticator App (Windows Phone)]
<br><br>
=={{header|C sharp|C#}}==
<syntaxhighlight lang="csharp">using System;
using System.Security.Cryptography;
namespace RosettaTOTP
{
public class TOTP_SHA1
{
private byte[] K;
public TOTP_SHA1()
{
GenerateKey();
}
public void GenerateKey()
{
using (RandomNumberGenerator rng = new RNGCryptoServiceProvider())
{
/* Keys SHOULD be of the length of the HMAC output to facilitate
interoperability.*/
K = new byte[HMACSHA1.Create().HashSize / 8];
rng.GetBytes(K);
}
}
public int HOTP(UInt64 C, int digits = 6)
{
var hmac = HMACSHA1.Create();
hmac.Key = K;
hmac.ComputeHash(BitConverter.GetBytes(C));
return Truncate(hmac.Hash, digits);
}
public UInt64 CounterNow(int T1 = 30)
{
var secondsSinceEpoch = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalSeconds;
return (UInt64)Math.Floor(secondsSinceEpoch / T1);
}
private int DT(byte[] hmac_result)
{
int offset = hmac_result[19] & 0xf;
int bin_code = (hmac_result[offset] & 0x7f) << 24
| (hmac_result[offset + 1] & 0xff) << 16
| (hmac_result[offset + 2] & 0xff) << 8
| (hmac_result[offset + 3] & 0xff);
return bin_code;
}
private int Truncate(byte[] hmac_result, int digits)
{
var Snum = DT(hmac_result);
return Snum % (int)Math.Pow(10, digits);
}
}
class Program
{
static void Main(string[] args)
{
var totp = new TOTP_SHA1();
Console.WriteLine(totp.HOTP(totp.CounterNow()));
}
}
}
</syntaxhighlight>
=={{header|Caché ObjectScript}}==
<
Class Utils.Security [ Abstract ]
{
Line 108 ⟶ 182:
}
</syntaxhighlight>
{{out|Example}}
<pre>
Line 123 ⟶ 197:
M4AKQBFI252H4BWO
</pre>
=={{header|Go}}==
A slightly [https://github.com/gwwfps/onetime/pull/1 fixed] version of a [https://github.com/gwwfps/onetime package by Zitao Zhang] (released under a [https://github.com/gwwfps/onetime/blob/master/LICENSE simplified BSD license]).
<
// implementing the HOTP and TOTP algorithms as specified by IETF RFC-4226
// and RFC-6238.
Line 264 ⟶ 273:
p[0] &= 0x7f
return p
}</
{{out|Example use}}
(in a format that gets put into the [https://godoc.org/github.com/dchapes/onetime generated documentation])
<
import (
Line 305 ⟶ 314:
var code = otp.TOTP(secret)
fmt.Println(code)
}</
=={{header|J}}==
<syntaxhighlight lang="j">DA =: '0123456789ABCDEF'
to_bytes =: 16 16#.(2,~2%~#)$ DA i. ]
upper =: 1&(3!:12)
xor =: 22 b.
and =: 17 b.
hmac_sha1 =: {{
sha1 =. _1&(128!:6)
b_size =. 512 % 8
pad_key =. b_size {.]
block_sized_key =. pad_key a.&i. x
o_key_pad =. block_sized_key xor b_size $ 16b5c
i_key_pad =. block_sized_key xor b_size $ 16b36
hashed =. sha1 (i_key_pad { a.), y
a. i. sha1 (o_key_pad { a.), hashed }}
totp =: {{
h =. x hmac_sha1&:(a. {~ to_bytes&]) y
offset =. 16bf and {: h
1000000|16b7fffffff and (4$256)#. 4 {. offset |. h }}
</syntaxhighlight>
{{out|Example use}}
<syntaxhighlight lang="j">time =: '0000000000000001' NB. 64-bit timestamp in hex format
secrete =: 'AB54A98CEB1F0AD2' NB. secrete key in hex format
time totp secrete NB. 758742
</syntaxhighlight>
=={{header|Julia}}==
<
using SHA
Line 321 ⟶ 363:
end
#see also https://github.com/ylxdzsw/TOTP.jl
hmac(hashfunc, bs=64) = (key, msg, blocksize=bs) -> hmac(key, msg, hashfunc, blocksize)
Line 345 ⟶ 388:
sleep(15)
end
</
<pre>
656601
Line 356 ⟶ 399:
</pre>
=={{header|
{{trans|Go}}
We borrowed the HMAC function from Julia solution, but didn’t apply a hash on the key at beginning. This way, we obtain the same result as Go for the “Simple” example.
Note that due to the interface of the hash function in module “std/sha1”, we have chosen to work with sequences of characters rather than sequences of bytes. The other way is of course possible, but maybe less convenient.
<syntaxhighlight lang="nim">import endians, math, sequtils, std/sha1, times
type
HashFunc = proc(msg: openArray[char]): seq[char]
OneTimePassword = object
timeStep: Duration # Length of each time step for TOTP.
baseTime: Time # The start time for TOTP step calculation.
hash: HashFunc # Hash algorithm used with HMAC.
func sha1Hash(msg: openArray[char]): seq[char] =
mapIt(@(Sha1Digest(secureHash(msg))), char(it))
func `xor`(s: seq[char]; val: byte): seq[char] =
## Apply a XOR to the chars of a sequence.
s.mapIt(char(it.byte xor val))
func hmac(key, msg: openArray[char]; hashFunc: HashFunc; blockSize = 64): seq[char] =
## Compute a HMAC for gien key, message, hash function and block size.
var key = @key
let paddingNeeded = blockSize - key.len
if paddingNeeded > 0: key.setLen(blockSize)
result = hashFunc((key xor 0x5c) & hashFunc((key xor 0x36) & @msg))
func simple(digit: int): OneTimePassword =
## Return a new OneTimePassword with the specified HTOP code length,
## SHA-1 as the HMAC hash algorithm, the Unix epoch as the base time, and
## 30 seconds as the step length.
doAssert digit in 6..9, "HTOP code length must be in 6..9."
let step = initDuration(seconds = 30)
result = OneTimePassword(digit: digit, timeStep: step, baseTime: fromUnix(0), hash: sha1Hash)
func hmacSum(otp: OneTimePassword; secret: openArray[char]; count: uint64): seq[char] =
var count = count
var beCount: uint64
bigEndian64(beCount.addr, count.addr)
let msg = cast[array[8, char]](beCount)
result = hmac(secret, msg, otp.hash)
func dt(hs: seq[char]): seq[char] =
let offset = hs[^1].byte and 0xf
result = hs[offset..offset+3]
result[0] = char(result[0].byte and 0x7f)
func truncate(otp: OneTimePassword; hs: seq[char]): uint64 =
let sbits = dt(hs)
let snum = sbits[3].uint64 or sbits[2].uint64 shl 8 or
sbits[1].uint64 shl 16 or sbits[0].uint64 shl 24
result = snum mod 10u^otp.digit
func hotp(otp: OneTimePassword; secret: openArray[char]; count: uint64): uint64 =
let hs = otp.hmacSum(secret, count)
result = otp.truncate(hs)
func steps(otp: OneTimePassword; t: Time): uint64 =
let elapsed = t - otp.baseTime
result = uint64(elapsed.inSeconds div otp.timeStep.inSeconds)
proc totp(otp: OneTimePassword; secret: openArray[char]): uint64 =
## Return a TOTP code calculated with the current time and the given secret.
otp.hotp(secret, otp.steps(getTime()))
when isMainModule:
proc exampleSimple =
## Simple 6-digit HOTP code.
const secret = "SOME_SECRET"
var counter: uint64 = 123456
let otp = simple(6)
let code = otp.hotp(secret, counter)
echo code
# Output:
# 260040
proc exampleAuthenticator =
## Google authenticator style 8-digit TOTP code.
const secret = "SOME_SECRET"
let otp = simple(8)
let code = otp.totp(secret)
echo code
echo "Simple:"
exampleSimple()
echo "Google authenticator:"
exampleAuthenticator()</syntaxhighlight>
{{out}}
<pre>Simple:
260040
Google authenticator:
94364703</pre>
=={{header|Perl}}==
{{trans|Raku}}
<syntaxhighlight lang="perl"># 20200704 added Perl programming solution
use strict;
use warnings;
use Authen::OATH;
my $message = "show me the monKey"; # convert to base32 is optional
my $oath = Authen::OATH->new(); # default SHA1 and TI=30
for ( my $t = 2177452800 ; $t < 2177452919 ; $t += 13 ) {
print "At ", scalar gmtime $t, " : ", $oath->totp( $message, $t ), "\n" ;
}</syntaxhighlight>
{{out}}
<pre>
At Sat Jan 1 00:00:00 2039 : 950428
At Sat Jan 1 00:00:13 2039 : 950428
At Sat Jan 1 00:00:26 2039 : 950428
At Sat Jan 1 00:00:39 2039 : 361382
At Sat Jan 1 00:00:52 2039 : 361382
At Sat Jan 1 00:01:05 2039 : 022576
At Sat Jan 1 00:01:18 2039 : 022576
At Sat Jan 1 00:01:31 2039 : 341623
At Sat Jan 1 00:01:44 2039 : 341623
At Sat Jan 1 00:01:57 2039 : 341623
</pre>
=={{header|Phix}}==
{{trans|Perl}}
Note the byte ordering of hmac (etc) is suspect and may change, hence bmap below
<!--<syntaxhighlight lang="phix">-->
<span style="color: #7060A8;">requires</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"1.0.1"</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- sha1.e added</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">sha1</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">hmac</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">bmap</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">8</span><span style="color: #0000FF;">,</span><span style="color: #000000;">7</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">,</span><span style="color: #000000;">5</span><span style="color: #0000FF;">,</span><span style="color: #000000;">12</span><span style="color: #0000FF;">,</span><span style="color: #000000;">11</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">,</span><span style="color: #000000;">16</span><span style="color: #0000FF;">,</span><span style="color: #000000;">15</span><span style="color: #0000FF;">,</span><span style="color: #000000;">14</span><span style="color: #0000FF;">,</span><span style="color: #000000;">13</span><span style="color: #0000FF;">,</span><span style="color: #000000;">20</span><span style="color: #0000FF;">,</span><span style="color: #000000;">19</span><span style="color: #0000FF;">,</span><span style="color: #000000;">18</span><span style="color: #0000FF;">,</span><span style="color: #000000;">17</span><span style="color: #0000FF;">}</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">dt</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">hmac_result</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">digits</span><span style="color: #0000FF;">=</span><span style="color: #000000;">6</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">hmac_result</span><span style="color: #0000FF;">[</span><span style="color: #000000;">bmap</span><span style="color: #0000FF;">[$]],</span><span style="color: #000000;">#0F</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">4</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">*</span><span style="color: #000000;">#100</span><span style="color: #0000FF;">+</span><span style="color: #000000;">hmac_result</span><span style="color: #0000FF;">[</span><span style="color: #000000;">bmap</span><span style="color: #0000FF;">[</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]]</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span> <span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">,</span><span style="color: #000000;">#7F</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">10</span><span style="color: #0000FF;">,</span><span style="color: #000000;">digits</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">a</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">totp</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">msg</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">ts</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">/</span><span style="color: #000000;">30</span><span style="color: #0000FF;">),</span><span style="color: #000000;">8</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">hmac_sha1</span><span style="color: #0000FF;">(</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">reverse</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">dt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">timedate</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #000000;">set_timedate_formats</span><span style="color: #0000FF;">({</span><span style="color: #008000;">"Mmm dth yyyy h:mm:ss"</span><span style="color: #0000FF;">})</span>
<span style="color: #000000;">timedate</span> <span style="color: #000000;">td0</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">parse_date_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Jan 1st 1970 00:00:00"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">message</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"show me the monKey"</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">to</span> <span style="color: #000000;">9</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">t</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2177452800</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i</span><span style="color: #0000FF;">*</span><span style="color: #000000;">13</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">format_timedate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">adjust_timedate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">td0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">t</span><span style="color: #0000FF;">))</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"At %s : %06d\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">d</span><span style="color: #0000FF;">,</span><span style="color: #000000;">totp</span><span style="color: #0000FF;">(</span><span style="color: #000000;">message</span><span style="color: #0000FF;">,</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
At Jan 1st 2039 0:00:00 : 950428
At Jan 1st 2039 0:00:13 : 950428
At Jan 1st 2039 0:00:26 : 950428
At Jan 1st 2039 0:00:39 : 361382
At Jan 1st 2039 0:00:52 : 361382
At Jan 1st 2039 0:01:05 : 022576
At Jan 1st 2039 0:01:18 : 022576
At Jan 1st 2039 0:01:31 : 341623
At Jan 1st 2039 0:01:44 : 341623
At Jan 1st 2039 0:01:57 : 341623
</pre>
=={{header|PicoLisp}}==
Using the <tt>sha1</tt> function defined at ''[[SHA-1#PicoLisp]]'':
<
(de hmac ("Fun" Msg Key)
Line 455 ⟶ 647:
(test
(cdr L)
(totp (mapcar char (chop "12345678901234567890")) (car L) 8) ) )</
=={{header|Racket}}==
This includes BASE32 encoding, token based authentication and other such stuff.
<
(require (only-in web-server/stuffers/hmac-sha1 HMAC-SHA1))
Line 603 ⟶ 795:
(base32-encode-bytes #"Super Secret Password Key 88!")
=> #"KN2XAZLSEBJWKY3SMV2CAUDBONZXO33SMQQEWZLZEA4DQII="
))</
{{out}}
Line 617 ⟶ 809:
oh dear... fall back one time-frame...
742249 is *that* the same? #t</pre>
=={{header|Raku}}==
(formerly Perl 6)
This is a minimal attempt that covers only the "Time-based" part of the requirement.
<syntaxhighlight lang="raku" line># Reference:
# https://github.com/retupmoca/P6-Digest-HMAC
use v6.d;
use Digest::HMAC;
use Digest::SHA;
sub totp (Str \secret, DateTime \counter, Int \T0=0, Int \T1=30 --> Str) {
my \key = ( counter - DateTime.new(T0) ).Int div T1;
return hmac-hex(key.Str, secret, &sha1).substr(0,6) # first 6 chars of sha1
}
my $message = "show me the monKey";
say "Deterministic output at ", DateTime.new(2177452800), " with fixed checks,";
loop (my $t = 2177452800 ; $t < 2177452900 ; $t+= 17 ) { # Y2038 safe
say totp $message, DateTime.new($t);
}
say "Current time output at ", DateTime.new(now), " with random checks,";
loop (my $n = 0 ; $n < 6 ; $n++, sleep (13..23).roll ) {
say totp $message, DateTime.new(now);
}
</syntaxhighlight>
{{out}}
<pre>Deterministic output at 2039-01-01T00:00:00Z with fixed checks,
34ca2a
acfa3f
950fc3
950fc3
a2d4ea
a2d4ea
Current time output at 2019-03-31T15:00:01.765312Z with random checks,
4e36de
d4e9f8
d4e9f8
077e2c
63bbb5
63bbb5</pre>
=={{header|Tcl}}==
Line 622 ⟶ 857:
This TOTP/HOTP module clocks in small by taking advantage of [https://core.tcl.tk/tcllib/doc/trunk/embedded/www/toc.html tcllib's] existing hashing and base32 modules.
<syntaxhighlight lang="tcl">
# rfc6238 contains examples of hotp with 8-digit modulus and sha1/sha256/sha512 hmac
#
Line 630 ⟶ 865:
namespace eval ::totp {
package require sha1
oo::class create totp {
variable Secret
Line 659 ⟶ 894:
hotp $Secret $bytes
}
}
proc hotp {secret bytes {length 6}} {
set hmac [sha1::hmac -bin $secret $bytes]
set ofs [string index $hmac end]
Line 669 ⟶ 904:
set chunk [string range $hmac $ofs $ofs+4]
binary scan $chunk I code
return [format %0${length}.${length}d [expr {($code & 0x7fffffff) %
}
namespace export *
}
Line 692 ⟶ 928:
}
assert {{306281 553572 304383} eq [google 1400000000]}
}</
=={{header|Wren}}==
{{trans|Go}}
{{libheader|Wren-long}}
{{libheader|Wren-crypto}}
{{libheader|Wren-date}}
{{libheader|Wren-srandom}}
As Wren-cli currently has no way of determining the Unix time, this needs to be input as a command line parameter so we can track it from there.
<syntaxhighlight lang="wren">import "os" for Process
import "./long" for ULong
import "./crypto" for Bytes, Sha1, Sha256, Hmac
import "./date" for Date
import "./srandom" for SRandom
var StartTime = null // time program was started (as a Unix timestamp)
class OneTimePassword {
construct new(digit, timeStep, baseTime, hashClass) {
_digit = digit // length of code generated
_timeStep = timeStep // length of each time step for TOTP
_baseTime = baseTime // start time for TOTP step calculation (as a Unix timestamp)
_hashClass = hashClass // hash class to be used with HMAC
}
// Convenience version of above which uses defaults values for all except 'digit' parameter.
static simple(digit) { new(digit, 30, 0, Sha1) }
// Returns a HOTP code with the given secret and counter.
hotp(secret, count) { truncate_(hmacSum_(secret, count)) }
// Returns a TOTP code calculated with the current time and the given secret.
totp(secret) { hotp(secret, steps_(timeNow_)) }
/* private helper methods */
hmacSum_(secret, count) {
var msg = ULong.new(count).toBytes[-1..0] // big-endian
return Bytes.fromHexString(Hmac.digest(secret, msg, Sha1))
}
dt_(hs) {
var offset = hs[-1] & 0xf
var p = hs[offset...offset+4]
p[0] = p[0] & 0x7f
return p
}
truncate_(hs) {
var sbits = dt_(hs)
var snum = Bytes.toIntBE(sbits)
var pwr = 10.pow(_digit)
return snum % pwr
}
steps_(now) { ((now - _baseTime)/_timeStep).floor }
timeNow_ { (StartTime + System.clock).floor }
}
var args = Process.arguments
if (args.count != 1) {
System.print("Please pass the Unix timestamp when starting the program.")
return
}
StartTime = Num.fromString(args[0])
var secret = "SOME_SECRET".bytes.toList
// Simple 6-digit HOTP code.
var otp = OneTimePassword.simple(6)
System.print(otp.hotp(secret, 123456))
// Google authenticator style 8-digit TOTP code.
otp = OneTimePassword.simple(8)
System.print(otp.totp(secret))
// Custom 9 digit, 5 second step TOTP starting on midnight 2000-01-01 UTC, using Sha256.
var baseTime = Date.new(2000, 1, 1).unixTime
otp = OneTimePassword.new(9, 5, baseTime, Sha256)
System.print(otp.totp(secret))
// As above using a random, 32 byte, Base32 key
var alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" // for Base32
var randKey = List.filled(32, null)
for (i in 0..31) randKey[i] = alphabet[SRandom.int(32)]
System.print(otp.totp(randKey.join().bytes.toList))</syntaxhighlight>
{{out}}
Sample output:
<pre>
$ date '+%s'
1707913906
$ wren-cli Time-based_one-time_password_algorithm.wren 1707913906
260040
38559208
185760458
556237229
</pre>
=={{header|zkl}}==
Uses the MsgHash dll, which includes SHA-1, SHA-256 hashes and HMAC routines for SHA-* and MD5.
{{trans|Go}}
<
// OneTimePassword stores the configuration values relevant to HOTP/TOTP calculations.
Line 733 ⟶ 1,066:
fcn totp(secret){ hotp(secret, steps(Time.Clock.time())) }
fcn steps(now) { (now - baseTime)/timeStep } // elapsed time chunked
} // OneTimePassword</
Note: MsgHash hashes return a string by default, they can also return the hash as bytes. Ditto the HMAC routines, it is the third parameter. So, to create a hmac that returns bytes, use (eg) MsgHash.extra.hmacSHA1.fp2(False), this creates a partial application (closure) of the hmac using SHA-1 fixing the third parameter as False.
{{out|Example uses}}
<
// Simple 6-digit HOTP code:
secret := "SOME_SECRET";
Line 761 ⟶ 1,094:
code := otp.totp(secret);
println(code) //-->eg 707355416
}();</
{{out|Example use}}
Showing how to sync with changes over time. A six digit OTP w/MD5 changing every 17 seconds. Latency can effect the result when totp is called at a time boundary, so a retry may be required.
<
secret,ts:= "SOME_SECRET",17;
otp := OneTimePassword(6,ts,Time.Clock.time(),MsgHash.extra.hmacMD5.fp2(False));
Line 774 ⟶ 1,107:
Atomic.sleep(10);
}
}</
{{out}}
<pre>
Line 791 ⟶ 1,124:
{{out|HMAC code}}
The MsgHash HMAC routines are pretty simple (the hash code is C), included here for completeness:
<
fcn hmac(key,msg,hashFcn,asString){
blkSz,H,Hx := 64,hashFcn.fp1(1,Data()), (asString and hashFcn or H);
Line 804 ⟶ 1,137:
fcn hmacSHA1( key,msg,asString=True){ hmac(key,msg,MsgHash.SHA1, asString) }
fcn hmacSHA256(key,msg,asString=True){ hmac(key,msg,MsgHash.SHA256,asString) }
fcn hmacMD5( key,msg,asString=True){ hmac(key,msg,Utils.MD5.calc,asString) }</
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