04-06-2019, 10:49 PM

Hi,

Could you please help me sort out how to properly compute PMKID?

I recorded the hash with hcxdumptool and converted with hcxpcaptool. I have a code that computes SHA-1 hash as a function of key (char) and message (char). I want to calculate PMKID (the first string in the file) using the SHA-1 code.

This thread https://hashcat.net/forum/thread-7717.html says that

1) PMKID = HMAC-SHA1-128(PMK, "PMK Name" | MAC_AP | MAC_STA)

2) PMK= PBKDF2(HMAC−SHA1, passphrase, ssid, 4096, 256)

Should I compute PMK by iterating SHA-1 calculation 4096 times? How do I choose the block size? What is ssid? Is it ESSID of the AP? Should the ssid input be converted to HEX? Also, the output of SHA-1 is 40 hex digits long. How do I make it 256 bytes long?

For the PMKID calculation, do I use PMK in hex as input? What is the second argument?

Thanks.

Could you please help me sort out how to properly compute PMKID?

I recorded the hash with hcxdumptool and converted with hcxpcaptool. I have a code that computes SHA-1 hash as a function of key (char) and message (char). I want to calculate PMKID (the first string in the file) using the SHA-1 code.

This thread https://hashcat.net/forum/thread-7717.html says that

1) PMKID = HMAC-SHA1-128(PMK, "PMK Name" | MAC_AP | MAC_STA)

2) PMK= PBKDF2(HMAC−SHA1, passphrase, ssid, 4096, 256)

Should I compute PMK by iterating SHA-1 calculation 4096 times? How do I choose the block size? What is ssid? Is it ESSID of the AP? Should the ssid input be converted to HEX? Also, the output of SHA-1 is 40 hex digits long. How do I make it 256 bytes long?

For the PMKID calculation, do I use PMK in hex as input? What is the second argument?

Thanks.