/ 
App-FuguSeed-0.2.0
/ App::FuguSeed::Last

NAME

App::FuguSeed::Last - the check word of 11 seed words and two dice

SYNOPSIS

use App::FuguSeed::Last;

exit App::FuguSeed::Last->run(@ARGV);

DESCRIPTION

App::FuguSeed::Last holds the face check, the check word, and the flow of the program fuguseed-last. It reads words 1 to 11 from the first line of standard input, and the YELLOW face and the BLUE face of word 12 from the second line. It writes the check word to standard output.

It is the one module of the program that touches a stream. The three standard streams are the one contact of the program with the computer: no module of the program opens a file, spawns a process, or reads an environment variable.

A failure prints one line to standard error. The line names the word position, the count, or the die that failed, never a word or a face. The check word leaves on standard output only.

fault

fault($faces) returns the failure message for the fields of the array reference $faces, or undef when the fields pass the check. The array must hold two fields. The YELLOW face must be one of the numbers 1 to 8, and the BLUE face one of the numbers 1 to 16, with no sign and no leading zero.

check_word

check_word($words, $yellow, $blue) returns the one word of the BLUE row of word 12 that makes the checksum valid. The faces give the first index of the row, (Y-1)*256 + (B-1)*16. The 11 indexes and the 7 high bits of that index are the 128 entropy bits. The check word is the word of the first index of the row plus the checksum. The method computes that word, and it runs no trial loop.

run

run(@argument) reads the two lines, prints the check word, and returns the exit code.

RETURN VALUES

fault() returns undef for two good faces. check_word() returns one word of the list. run() returns 0 for a success, 1 for a failure, and 2 for a usage error.

ERRORS

An argument is a usage error: run() prints one usage line to standard error and returns 2. Another count than 11 words, a word outside the list, another count than two fields, and a bad face are failures: run() prints one line to standard error and returns 1.

check_word() expects 11 words of the list and two good faces. Call App::FuguSeed::Mnemonic and fault() first.

SEE ALSO

fuguseed-last(1), fuguseed-qr(1), and App::FuguSeed::Mnemonic.

AUTHORS

Dick Olsson <hi@senzilla.io>