CkPython Requires Chilkat v11.0.0+

Validate a JWS Using ECDSA P-521 SHA-512

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses ECDSA P-521 SHA-512 CkPython

import sys
import chilkat

success = False

#  This requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  This example takes a JSON signature in compact serialization format,
#  and uses an ECDSA public key to validate and recover the protected header and payload.

#  We only need a public key for signature validation.  This is the ECDSA public key
#  that is used:

#       {"kty":"EC", 
#        "crv":"P-521", 
#        "x":"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk", 
#        "y":"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2" 
#       } 

sbPubKey = chilkat.CkStringBuilder()
sbPubKey.Append("{\"kty\":\"EC\",")
sbPubKey.Append("\"crv\":\"P-521\",")
sbPubKey.Append("\"x\":\"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk\",")
sbPubKey.Append("\"y\":\"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2\"")
sbPubKey.Append("}")

pubKey = chilkat.CkPublicKey()
success = pubKey.LoadFromString(sbPubKey.getAsString())
if (success == False):
    print(pubKey.lastErrorText())
    sys.exit()

jws = chilkat.CkJws()

#  Set the ECC public key:
signatureIndex = 0
jws.SetPublicKey(signatureIndex,pubKey)

#  Load the JWS.
sbJws = chilkat.CkStringBuilder()
sbJws.Append("eyJhbGciOiJFUzUxMiJ9")
sbJws.Append(".")
sbJws.Append("UGF5bG9hZA")
sbJws.Append(".")
sbJws.Append("AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq")
sbJws.Append("wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp")
sbJws.Append("EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn")

success = jws.LoadJwsSb(sbJws)
if (success == False):
    print(jws.lastErrorText())
    sys.exit()

#  Validate the 1st (and only) signature at index 0..
v = jws.Validate(signatureIndex)
if (v < 0):
    #  Perhaps Chilkat was not unlocked or the trial expired..
    print("Method call failed for some other reason.")
    print(jws.lastErrorText())
    sys.exit()

if (v == 0):
    print("Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both.")
    sys.exit()

#  If we get here, the signature was validated..
print("Signature validated.")
print("--")

#  Recover the original content:
print("Recovered content:")
print(jws.getPayload("utf-8"))
print("--")

#  Examine the protected header:

joseHeader = chilkat.CkJsonObject()
success = jws.GetProtectedH(signatureIndex,joseHeader)
if (success == False):
    print(jws.lastErrorText())
    sys.exit()

joseHeader.put_EmitCompact(False)

print("Protected (JOSE) header:")
print(joseHeader.emit())

#  Output:
#  (the string "Payload" was the content that was signed.)

#  	Signature validated.
#  	--
#  	Recovered content:
#  	Payload
#  	--
#  	Protected (JOSE) header:
#  	{
#  	  "alg": "ES512"
#  	}