verilog-otp

VerilogHDL implementation of One-Time Password Algorithm (HOTP)

Modules

SHA1

Implementation of RFC-3174 US Secure Hash Algorithm 1 (SHA-1). Takes 81 clocks for processing each block.

direction	width	name	details
input	1	clk	clock
input	1	reset	positive reset, must be turned on before each hash calculation
input	1	feed	positive feed flag, must be turned on before each message block input
input	512	message	message input, must be padded with the rule defined in SHA-1
output	160	hash	hash output, could be read if done == 1
output	1	done	process ended flag, turned on at the end of the process of each block

TestSHA1

Tests SHA1 module.

HMACSHA1

LIMITED implementation of HMAC-SHA-1, RFC-2104 Keyed-Hashing for Message Authentication (HMAC) with SHA-1. Takes at most 250 clocks for processing.

This module accepts at most one block of message input (512 bytes) because it is enough to generate HOTP.

direction	width	name	details
input	1	clk	clock
input	1	reset	positive reset, must be turned on before each hash calculation
input	512	input_message	message input, must be padded with the rule defined in SHA-1 but length of the message should be 512 + len(input_message)
input	512	key	key input, must be padded with zeros as defined in HMAC
output	160	hash	hash output, could be read if done == 1
output	1	done	process ended flag, turned on at the end of the process

TestHMACSHA1

Tests HMACSHA1 module.

HOTP

Implementation of RFC-4226 HOTP: An HMAC-Based One-Time Password Algorithm. Takes at most 250 clocks for processing.

This module only supports 6-digit output.

direction	width	name	details
input	1	clk	clock
input	1	reset	positive reset, must be turned on before each password calculation
input	512	key	key input, must be padded with zeros as defined in HMAC
input	64	counter	counter value, incremented by 1 for HOTP
output	20	code	6-digit password output, could be read if done == 1
output	1	done	process ended flag, turned on at the end of the process

TestHOTP

Tests HOTP module.

GenClock

Clock generator, for test purpose.

Support for Time-Based One-Time Password (TOTP)

You have to prepare a way to get accurate UNIX Time. Just provide (UNIX Time in seconds) / 30 into HOTP module as counter value.

License

MIT License

Copyright (c) 2022 kyori19

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