(Tcl) Load ECC Public Key from JWK Format (JSON Web Key)

Demonstrates how to load an ECC public key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

#  Note: This example requires Chilkat v9.5.0.66 or later.

#  First build a JWK sample to load..
set json [new_CkJsonObject]

CkJsonObject_UpdateString $json "kty" "EC"
CkJsonObject_UpdateString $json "crv" "P-256"
CkJsonObject_UpdateString $json "x" "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE"
CkJsonObject_UpdateString $json "y" "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU"

#  The JSON contains the following:
#  {
#    "kty": "EC",
#    "crv": "P-256",
#    "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
#    "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
#  }

#  Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
CkJsonObject_put_EmitCompact $json 0

#  Show the JWK string to be loaded:
set jwkStr [CkJsonObject_emit $json]

set pubKey [new_CkPublicKey]

#  The LoadFromString method will automatically detect the format.
set success [CkPublicKey_LoadFromString $pubKey $jwkStr]
if {[expr $success != 1]} then {
    puts [CkPublicKey_lastErrorText $pubKey]
    delete_CkJsonObject $json
    delete_CkPublicKey $pubKey
    exit
}

#  OK.. the JWK is loaded.  It can be used in whatever way desired...

#  The key can be retrieved in any other format, such as XML or PEM..
puts [CkPublicKey_getXml $pubKey]

#  XML output:
#  <ECCPublicKey curve="secp256r1"
#     x="A01532A3C0900053DE60FBEFEFCCA58793301598D308B41E6F4E364E388C2711"
#     y="BEF432C599148C94143D4FF46C2CB73E3E6A41D7EEF23C047EA11E60667DE425">
#     MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAAAAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA///////////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSdNgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeTMBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
#  </ECCPublicKey>

#  Choose PCKS1 or PCKS8 PEM format..
set bPreferPkcs1 0
puts [CkPublicKey_getPem $pubKey $bPreferPkcs1]

#  PEM output
#  -----BEGIN PUBLIC KEY-----
#  MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
#  AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
#  ///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
#  NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
#  RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
#  //////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeT
#  MBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
#  -----END PUBLIC KEY-----

delete_CkJsonObject $json
delete_CkPublicKey $pubKey