Sample code for 30+ languages & platforms
Tcl

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

See more ECC Examples

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 Downloads

Tcl

load ./chilkat.dll

set success 0

# 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 $jwkStr]
if {$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