encode_keychange (1) - Linux Man Pages
encode_keychange: produce the KeyChange string for SNMPv3
NAMEencode_keychange - produce the KeyChange string for SNMPv3
SYNOPSISencode_keychange -t md5|sha1 [OPTIONS]
DESCRIPTIONencode_keychange produces a KeyChange string using the old and new passphrases as described in Section 5 of RFC 2274 "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)". -t option is mandatory and specifies the hash transform type to use.
The transform is used to convert passphrase to master key for a given user (Ku), convert master key to the localized key (Kul), and to hash the old Kul with the random bits.
Passphrases are obtained by examining a number of sources until success (in order listed):
- command line options (see -N and -O options below);
- the file $HOME/.snmp/passphrase.ek which should only contain two lines with old and new passphrase;
- standard input -or- user input from the terminal.
- -E [0x]<engineID> EngineID used for Kul generation.
- <engineID> is intepreted as a hex string when preceded by 0x, otherwise it is treated as a text string. If no <engineID> is specified, it is constructed from the first IP address for the local host.
- Force passphrases to be read from standard input.
- Display the help message.
- -N "<new_passphrase>"
- Passphrase used to generate the new Ku.
- -O "<old_passphrase>"
- Passphrase used to generate the old Ku.
- Turn off the prompt for passphrases when getting data from standard input.
- Be verbose.
- Echo passphrases to terminal.
The localized key method is defined in RFC 2274, Sections 2.6 and A.2, and
originally documented in