sha512 HardFault

[hugolgst]

Hello,

I am building on ATSAMD21E18A and for some reason when I use sha512.New in pbkdf2.Key, my program crashes and prints a single "f" in the logs.
I tried using sha256 and it works perfectly.

I identified that the problem happens when pbkdf2.Key is calling the Sum function, here:
https://cs.opensource.google/go/x/crypto/+/refs/tags/v0.7.0:pbkdf2/pbkdf2.go;l=61
https://cs.opensource.google/go/go/+/refs/tags/go1.20.2:src/crypto/sha512/sha512.go;l=282

I cannot seem to get more information on this issue, anyone got an idea?
Thank you in advance

–hugo

[hugolgst]

[dgryski]

Does this reproduce for native code or any other platform?

[hugolgst]

@dgryski The code works well on my machine but does not either on the board I am adding to TinyGo nor the Raspberry Pico.

[soypat]

I am struggling to reproduce the issue on the RP2040 (pico). I've come up with the following:

package main

import (
	"crypto/sha512"
	"time"

	"golang.org/x/crypto/pbkdf2"
)

func main() {
	const last = 4 * 256
	time.Sleep(time.Second)
	println("start program")
	var (
		salt = []byte("add some salt and pepper")
	)

	for i := 0; i < 10000; i++ {
		b := make([]byte, last+i)
		for j := 0; j < last+i; j++ {
			b[j] = byte(i)
		}
		b = pbkdf2.Key(b, salt, 2048, 64, sha512.New)
		println(string(b))
		time.Sleep(time.Second / 4)
	}
}

This is a Go program that generates and prints 10,000 PBKDF2 hashed keys. PBKDF2 is a key derivation function that is used to generate cryptographic keys from a password. In this program, the PBKDF2 function takes a byte slice and a salt as inputs, along with a few other parameters like the number of iterations and the length of the output key. The program generates a byte slice of increasing length on each iteration and hashes it using PBKDF2. The resulting hash is printed to the console, and the program waits for a quarter of a second before continuing to the next iteration.