create_challenge Method
Creates the challenge.
Syntax
def create_challenge() -> None: ...
Remarks
This method creates a challenge. After calling this method the challenge property will be populated with the created value.
When challenge_type is set to ctRandom the following properties are applicable:
When challenge_type is set to ctSignature the following properties are applicable:
In addition to creating the challenge this method will also create the ocra_suite which defines parameters required by the other party to calculate a response. The following properties are applicable to ocra_suite creation:
- challenge_format
- hash_algorithm
- response_length
- require_counter
- require_password
- require_time_stamp
- PasswordHashAlgorithm
- RequireSessionInfo
- SessionInfoLength
- TimeStepSize
- TimeStepUnit
Random Challenge Example
//First create the challenge on machine A Ocra ocra = new Ocra(); ocra.ChallengeType = OcraChallengeTypes.ctRandom; ocra.ChallengeLength = 10; ocra.ChallengeFormat = OcraChallengeFormats.cfNumeric; ocra.CreateChallenge(); string challenge = ocra.Challenge; //Value like "3891592139" string ocraSuite = ocra.OCRASuite; //Value "OCRA-1:HOTP-SHA1-6:QN10" //Send Challenge and OCRASuite to Machine B //Upon receiving the challenge on Machine B, calculate a response ocra = new Ocra(); ocra.OCRASuite = ocraSuite; //Received from other party ocra.Challenge = challenge; //Received from other party ocra.Key = "shared secret key"; ocra.CalculateResponse(); string response = ocra.Response; //Value like "574464" //Send Response back to Machine A //Upon receiving the response on Machine A, verify it ocra = new Ocra(); ocra.OCRASuite = ocraSuite; //Original OCRASuite saved before sending the original challenge ocra.Challenge = challenge; //Original challenge that was sent ocra.Response = response; //Received from other party ocra.Key = "shared secret key"; bool isValid = ocra.VerifyResponse(); //Returns True if verifiedSignature Challenge Example
//First create the challenge on machine A Ocra ocra = new Ocra(); ocra.ChallengeType = OcraChallengeTypes.ctSignature; ocra.ChallengeInput = "test input"; ocra.Key = "signature key"; ocra.ChallengeFormat = OcraChallengeFormats.cfHex; ocra.CreateChallenge(); string challenge = ocra.Challenge; //Value like "973131F0" string ocraSuite = ocra.OCRASuite; //Value "OCRA-1:HOTP-SHA1-6:QH08" //Send Challenge and OCRASuite to Machine B //Upon receiving the challenge on Machine B, calculate a response ocra = new Ocra(); ocra.OCRASuite = ocraSuite; //Received from other party ocra.Challenge = challenge; //Received from other party ocra.Key = "shared secret key"; ocra.CalculateResponse(); string response = ocra.Response; //Value like "574464" //Send Response back to Machine A //Upon receiving the response on Machine A, verify it ocra = new Ocra(); ocra.OCRASuite = ocraSuite; //Original OCRASuite saved before sending the original challenge ocra.Challenge = challenge; //Original challenge that was sent ocra.Response = response; //Received from other party ocra.Key = "shared secret key"; bool isValid = ocra.VerifyResponse(); //Returns True if verified