Linux "spkac" Command Line Options and Examples
SPKAC printing and generating utility
The spkac command processes Netscape signed public key and challenge (SPKAC) files. It can print out their contents, verify the signature and produce its own SPKACs from a supplied private key..
openssl spkac [-help] [-in filename] [-out filename] [-key keyfile] [-passin arg] [-challenge string]
[-pubkey] [-spkac spkacname] [-spksect section] [-noout] [-verify] [-engine id]
Command Line Options:
Print out a usage message.
spkac -help ...
This specifies the input filename to read from or standard input if this option is not specified. Ignoredif the -key option is used.
spkac -in ...
specifies the output filename to write to or standard output by default.
spkac -out ...
create an SPKAC file using the private key in keyfile. The -in, -noout, -spksect and -verify options areignored if present.
spkac -key ...
the input file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTSsection in openssl(1).
spkac -passin ...
specifies the challenge string if an SPKAC is being created.
spkac -challenge ...
allows an alternative name form the variable containing the SPKAC. The default is "SPKAC". This optionaffects both generated and input SPKAC files.
spkac -spkac ...
allows an alternative name form the section containing the SPKAC. The default is the default section.
spkac -spksect ...
don't output the text version of the SPKAC (not used if an SPKAC is being created).
spkac -noout ...
output the public key of an SPKAC (not used if an SPKAC is being created).
spkac -pubkey ...
verifies the digital signature on the supplied SPKAC.
spkac -verify ...
specifying an engine (by its unique id string) will cause spkac to attempt to obtain a functionalreference to the specified engine, thus initialising it if needed. The engine will then be set as thedefault for all available algorithms.EXAMPLESPrint out the contents of an SPKAC:openssl spkac -in spkac.cnfVerify the signature of an SPKAC:openssl spkac -in spkac.cnf -noout -verifyCreate an SPKAC using the challenge string "hello":openssl spkac -key key.pem -challenge hello -out spkac.cnfExample of an SPKAC, (long lines split up for clarity):SPKAC=MIG5MGUwXDANBgkqhkiG9w0BAQEFAANLADBIAkEA1cCoq2Wa3Ixs47uI7F\PVwHVIPDx5yso105Y6zpozam135a8R0CpoRvkkigIyXfcCjiVi5oWk+6FfPaD03u\PFoQIDAQABFgVoZWxsbzANBgkqhkiG9w0BAQQFAANBAFpQtY/FojdwkJh1bEIYuc\2EeM2KHTWPEepWYeawvHD0gQ3DngSC75YCWnnDdq+NQ3F+X4deMx9AaEglZtULwV\4=NOTESA created SPKAC with suitable DN components appended can be fed into the ca utility.SPKACs are typically generated by Netscape when a form is submitted containing the KEYGEN tag as part of thecertificate enrollment process.The challenge string permits a primitive form of proof of possession of private key. By checking the SPKACsignature and a random challenge string some guarantee is given that the user knows the private keycorresponding to the public key being certified. This is important in some applications. Without this it ispossible for a previous SPKAC to be used in a "replay attack".
spkac -engine ...