{
    "mode": "man",
    "parameter": "encode_keychange",
    "section": "1",
    "url": "https://www.chedong.com/phpMan.php/man/encode_keychange/1/json",
    "generated": "2026-06-16T22:13:54Z",
    "synopsis": "encodekeychange -t md5|sha1 [OPTIONS]",
    "sections": {
        "NAME": {
            "content": "encodekeychange - produce the KeyChange string for SNMPv3\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "encodekeychange -t md5|sha1 [OPTIONS]\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "encodekeychange  produces  a KeyChange string using the old and new passphrases as described\nin Section 5 of RFC 2274 \"User-based Security Model (USM) for version 3 of the Simple Network\nManagement  Protocol  (SNMPv3)\". -t option is mandatory and specifies the hash transform type\nto use.\n\nThe transform is used to convert passphrase to master key for a given user (Ku), convert mas‐\nter key to the localized key (Kul), and to hash the old Kul with the random bits.\n\nPassphrases are obtained by examining a number of sources until success (in order listed):\n\ncommand line options (see -N and -O options below);\n\nthe  file  $HOME/.snmp/passphrase.ek  which should only contain two lines with old and\nnew passphrase;\n\nstandard input -or-  user input from the terminal.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "",
            "subsections": [
                {
                    "name": "-E",
                    "content": "<engineID> is intepreted as a hex string when preceded by 0x, otherwise it is  treated\nas  a  text string. If no <engineID> is specified, it is constructed from the first IP\naddress for the local host.\n",
                    "flag": "-E"
                },
                {
                    "name": "-f",
                    "content": "",
                    "flag": "-f"
                },
                {
                    "name": "-h",
                    "content": "",
                    "flag": "-h"
                },
                {
                    "name": "-N",
                    "content": "Passphrase used to generate the new Ku.\n",
                    "flag": "-N"
                },
                {
                    "name": "-O",
                    "content": "Passphrase used to generate the old Ku.\n",
                    "flag": "-O"
                },
                {
                    "name": "-P",
                    "content": "",
                    "flag": "-P"
                },
                {
                    "name": "-v",
                    "content": "",
                    "flag": "-v"
                },
                {
                    "name": "-V",
                    "content": "",
                    "flag": "-V"
                }
            ]
        },
        "SEE ALSO": {
            "content": "The localized key method is defined in RFC 2274, Sections 2.6 and A.2, and  originally  docu‐\nmented in\n\nU.  Blumenthal, N. C. Hien, B. Wijnen, \"Key Derivation for Network Management Applica‐\ntions\", IEEE Network Magazine, April/May issue, 1997.\n\n\n\nV5.9.1                                       16 Nov 2006                         encodekeychange(1)",
            "subsections": []
        }
    },
    "summary": "encodekeychange - produce the KeyChange string for SNMPv3",
    "flags": [
        {
            "flag": "-E",
            "long": null,
            "arg": null,
            "description": "<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."
        },
        {
            "flag": "-f",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "-h",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "-N",
            "long": null,
            "arg": null,
            "description": "Passphrase used to generate the new Ku."
        },
        {
            "flag": "-O",
            "long": null,
            "arg": null,
            "description": "Passphrase used to generate the old Ku."
        },
        {
            "flag": "-P",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "-v",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "-V",
            "long": null,
            "arg": null,
            "description": ""
        }
    ],
    "examples": [],
    "see_also": []
}