Chacha20 Encryption

[stamun8]

Is there any way to bruteforce both chacha20 key and nonce(iV)?
Is there any explanation of the chacha20 hash format?

Code:

static const char *ST_PASS        = "hashcat_hashcat_hashcat_hashcat_";

static const char *ST_HASH        = "$chacha20$*0400000000000003*16*0200000000000001*5152535455565758*6b05fe554b0bc3b3";

[atom]

The 0200000000000001 is the IV

[stamun8]

The 5152535455565758 should be the plaintext.
The 6b05fe554b0bc3b3 should be the ciphertext.
Any ideas about *0400000000000003*16?

[atom]

sure, is the counter and offset. see tools/test_modules/m15400.pm for high level view