SNMPv3-Hash-Generator 0.2

Generates SNMPv3 hashes as described in rfc3414 suitable for use with ESXi and other SNMP daemons

A script to generate SNMPv3 keys as detailed by rfc3414 (passphrases expanded with a kdf, then hashed with the engine id). All key generation is done using the new cryptographically secure secrets library.

As I wrote this with ESXi in mind, it also emits a string suitable for configuring the SNMP daemon via esxcli/PowerCLI, but the hashes are standard and compatible with other SNMPv3 implementations.

With no arguments, it will generate an authentication and privacy passphrase with associated random engine ID in text form. –json will format the output as json.

The script is fully idempotent; if you take the parameters it generates randomly and re-enter them, you will get the same output a second time.

Dependencies

Runtime: Python 3.6 or greater.

Sample Output

Standard

User: observium
Auth: gaYA82XVtNaf3WLwRgoIs544ghP6f80S / f78359764ca382922fa382cf884e588031de575a
Priv: H5XEtRpxXVaGzXU5i2rFwPnYGr8SEzTp / 31a001a56a225fdfc1916bd60190405a1aa22ff0
Engine: 7ae1b0ff0aa2f3950566d3de2274d05a
ESXi USM String: observium/f78359764ca382922fa382cf884e588031de575a/31a001a56a225fdfc1916bd60190405a1aa22ff0/authpriv

JSON

{
  "user": "observium",
  "engine": "b2a50167b7c8512ddfc9d5765a3490af",
  "phrases": {
    "auth": "71rOhjfj6QVSy2mw5tBo7PueZ8KWSv60",
    "priv": "xwsvzht8NEcuwAlEpUKzMxKFWeH72sK9"
  },
  "hashes": {
    "auth": "fa0d5249293404502f9953b9514d0636a96c2cbc",
    "priv": "cccbdcfa603817df340514ecc22dfae8c4c412e8"
  },
  "esxi": "observium/fa0d5249293404502f9953b9514d0636a96c2cbc/cccbdcfa603817df340514ecc22dfae8c4c412e8/authpriv"}

It should go without saying, but DO NOT use the engine id or passphrases in the samples.

Usage

usage: snmpv3-hashgen [-h] [--auth AUTH] [--priv PRIV] [--engine ENGINE]
                      [--user USER] [--mode {authpriv,auth,priv,none}]
                      [--hash {md5,sha1}] [--json]

Convert an SNMPv3 auth or priv passphrase to sha1 or md5 hashes

optional arguments:
  -h, --help            show this help message and exit
  --auth AUTH           Authentication passphrase to be derived as a string
  --priv PRIV           Privacy passphrase to be derived as a string
  --engine ENGINE       Engine ID as hex string
  --user USER           SNMPv3 USM username (default "observium")
  --mode {authpriv,auth,priv,none}
                        SNMPv3 mode (default "authpriv")
  --hash {md5,sha1}     Hash algorithm to use (default "sha1")
  --json                Emit output as json