Chilkat2-Python

Validate JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) using HMAC SHA-256. Chilkat2-Python

import sys
import chilkat2

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 a MAC key to validate and recover the protected header and payload.

jws = chilkat2.Jws()

# Set the HMAC key:
hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"
signatureIndex = 0
jws.SetMacKey(signatureIndex,hmacKey,"base64url")

# Load the JWS.
jwsCompact = "eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ.dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
success = jws.LoadJws(jwsCompact)

# 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 MAC key was incorrect, the JWS was invalid, or both.")
    sys.exit()

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

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

# Examine the protected header:

joseHeader = chilkat2.JsonObject()
success = jws.GetProtectedH(signatureIndex,joseHeader)
if (success == False):
    print(jws.LastErrorText)
    sys.exit()

joseHeader.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:
# 	{ 
# 	  "typ": "JWT",
# 	  "alg": "HS256"
# 	}