Class: Mintotp::TOTP

Inherits:
Object
  • Object
show all
Defined in:
lib/mintotp/totp.rb

Instance Method Summary collapse

Instance Method Details

#hotp(key, counter, digits = 6, digest = 'sha1') ⇒ Object 



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# File 'lib/mintotp/totp.rb', line 21

def hotp(key, counter, digits=6, digest='sha1')
  key = Base32.decode "#{key}#{"="* ((8-key.length)%8)}"
  sha = OpenSSL::Digest::Digest.new(digest)
  counter = [counter].pack('Q>')
  hmac= OpenSSL::HMAC.digest(sha, key, counter)
  
  offset = hmac.bytes.last & 0x0f   
  bytes = hmac.bytes[offset..offset+4]

  # unpack by bytes shifting
  bytes[0] = bytes[0] & 0x7f
  bytes_as_integer = (bytes[0] << 24) + (bytes[1] << 16) + (bytes[2] << 8) + bytes[3]
  bytes_as_integer.modulo(10 ** digits).to_s.rjust(digits,'0')
end

#totp(key, time_step = 30, digits = 6, digest = 'sha1') ⇒ string

Returns if so.

Examples:

SECRET1 = "ZYTYYE5FOAGW5ML7LRWUL4WTZLNJAMZS"
minTotp = Mintotp::TOTP.new()
minTotp.totp(SECRET1)

Parameters:

  • secret (string) —

    key

  • TimeStep (integer) —

    Second Default is 30 Second in Google Authenticator

  • Number (integer) —

    of digits that will generate

  • : ('sha1') —

    hash name

Returns:

  • (string) —

    if so



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# File 'lib/mintotp/totp.rb', line 17

def totp(key, time_step=30, digits=6, digest='sha1')
  hotp(key, Time.now.to_i / time_step, digits, digest)
end