CkPython Requires Chilkat v11.0.0+

Validate JWS Using RSASSA-PKCS1-v1_5 SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses RSASSA-PKCS1-v1_5 SHA-256. 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 RSA public key to validate and recover the protected header and payload.

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

#       {"kty":"RSA", 
#        "n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx
#             HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs
#             D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH
#             SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV
#             MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8
#             NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ", 
#        "e":"AQAB"
#       }

sbPubKey = chilkat.CkStringBuilder()
sbPubKey.Append("{\"kty\":\"RSA\",")
sbPubKey.Append("\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx")
sbPubKey.Append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs")
sbPubKey.Append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH")
sbPubKey.Append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV")
sbPubKey.Append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8")
sbPubKey.Append("NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",")
sbPubKey.Append("\"e\":\"AQAB\"")
sbPubKey.Append("}")

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

jws = chilkat.CkJws()

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

#  Load the JWS.
sbJws = chilkat.CkStringBuilder()
sbJws.Append("eyJhbGciOiJSUzI1NiJ9")
sbJws.Append(".")
sbJws.Append("eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt")
sbJws.Append("cGxlLmNvbS9pc19yb290Ijp0cnVlfQ")
sbJws.Append(".")
sbJws.Append("cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7")
sbJws.Append("AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4")
sbJws.Append("BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K")
sbJws.Append("0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv")
sbJws.Append("hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB")
sbJws.Append("p0igcN_IoypGlUPQGe77Rw")

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 RSA 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:

#  	Signature validated.
#  	--
#  	Recovered content:
#  	{"iss":"joe", 
#  	 "exp":1300819380,
#  	 "http://example.com/is_root":true}
#  	--
#  	Protected (JOSE) header:
#  	{ 
#  	  "alg": "RS256"
#  	}