Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

load ./chilkat.dll

set success 0

set jws [new_CkJws]

#  Load the JWS compact serialization.
set jwsCompact "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>"
set success [CkJws_LoadJws $jws $jwsCompact]
if {$success == 0} then {
    puts [CkJws_lastErrorText $jws]
    delete_CkJws $jws
    exit
}

#  The file path is relative to the application's current working directory.  An absolute path
#  may also be used.  Supply the path appropriate to your own environment.
#  Load the signer's public key and set it for validating signature 0.
set pubKey [new_CkPublicKey]

set success [CkPublicKey_LoadFromFile $pubKey "qa_data/signer_pubkey.pem"]
if {$success == 0} then {
    puts [CkPublicKey_lastErrorText $pubKey]
    delete_CkJws $jws
    delete_CkPublicKey $pubKey
    exit
}

set success [CkJws_SetPublicKey $jws 0 $pubKey]
if {$success == 0} then {
    puts [CkJws_lastErrorText $jws]
    delete_CkJws $jws
    delete_CkPublicKey $pubKey
    exit
}

#  Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
set v [CkJws_Validate $jws 0]
if {$v < 0} then {
    puts [CkJws_lastErrorText $jws]
    delete_CkJws $jws
    delete_CkPublicKey $pubKey
    exit
}

if {$v != 1} then {
    puts "The signature is not valid."
    delete_CkJws $jws
    delete_CkPublicKey $pubKey
    exit
}

puts "The signature is valid."

delete_CkJws $jws
delete_CkPublicKey $pubKey