Ruby Requires Chilkat v11.0.0+

Validate JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

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

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

jws = Chilkat::CkJws.new()

#  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." + "\n";
    print jws.lastErrorText() + "\n";
    exit
end

if (v == 0)
    print "Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both." + "\n";
    exit
end

#  If we get here, the signature was validated..
print "Signature validated." + "\n";

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

#  Examine the protected header:

joseHeader = Chilkat::CkJsonObject.new()
success = jws.GetProtectedH(signatureIndex,joseHeader)
if (success == false)
    print jws.lastErrorText() + "\n";
    exit
end

joseHeader.put_EmitCompact(false)

print "Protected (JOSE) header:" + "\n";
print joseHeader.emit() + "\n";

#  Output:

#  	Signature validated.
#  	Recovered content:
#  	{"iss":"joe",
#  	 "exp":1300819380,
#  	 "http://example.com/is_root":true}
#  	Protected (JOSE) header:
#  	{ 
#  	  "typ": "JWT",
#  	  "alg": "HS256"
#  	}