com.amazon.pay.api

Class SignatureHelper

java.lang.Object

com.amazon.pay.api.SignatureHelper

public class SignatureHelper
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static int	TRAILER_FIELD

Constructor Summary

Constructors

Constructor and Description
SignatureHelper(PayConfiguration payConfiguration)

Method Summary

Modifier and Type	Method and Description
String	createCanonicalRequest(URI uri, String httpMethodName, Map<String,List<String>> parameters, String requestPayload, Map<String,List<String>> preSignedHeaders) Creates a string that includes the information from the request in a standardized(canonical) format.
Map<String,List<String>>	createPreSignedHeaders(URI uri, Map<String,String> header) Creates the mandatory headers required in the request
String	createStringToSign(String canonicalRequest, String algorithm) Creates the string that is going to be signe
String	generateSignature(String stringToSign, PrivateKey privateKey, AmazonSignatureAlgorithm algorithm) Generates a signature for the string passed in
String	getCanonicalizedHeaderString(Map<String,List<String>> preSignedHeaders) Generates a canonical headers string that consists of a list of all HTTP headers that are included with the request.
String	getCanonicalizedQueryString(Map<String,List<String>> parameters) Generates a canonical string that consists of all the query parameters
String	getSignedHeadersString(Map<String,List<String>> preSignedHeaders) Generates a string that is a list of headers names that are included in the canonical headers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TRAILER_FIELD

public static final int TRAILER_FIELD

See Also:

Constant Field Values

Constructor Detail

SignatureHelper

public SignatureHelper(PayConfiguration payConfiguration)

Method Detail

createCanonicalRequest

public String createCanonicalRequest(URI uri,
                                     String httpMethodName,
                                     Map<String,List<String>> parameters,
                                     String requestPayload,
                                     Map<String,List<String>> preSignedHeaders)
                              throws AmazonPayClientException

Creates a string that includes the information from the request in a standardized(canonical) format.

Parameters:

uri - The uri that needs to be executed

httpMethodName - the HTTP request method(GET,PUT,POST etc) to be used

parameters - the query parameters map

requestPayload - the payload to be sent with the request

preSignedHeaders - the mandatory headers required

Returns:

a canonical request

Throws:

AmazonPayClientException - algorithm requested is not available in the environment

createStringToSign

public String createStringToSign(String canonicalRequest,
                                 String algorithm)
                          throws NoSuchAlgorithmException

Creates the string that is going to be signe

Parameters:

canonicalRequest - The canonical request generated using the createCanonicalRequest() method

algorithm - The Amazon Signature Algorithm from payConfiguration

Returns:

the string to be signed

Throws:

NoSuchAlgorithmException - exception thrown when the cryptographic algorithm requested is not available in the environment

generateSignature

public String generateSignature(String stringToSign,
                                PrivateKey privateKey,
                                AmazonSignatureAlgorithm algorithm)
                         throws NoSuchAlgorithmException,
                                NoSuchProviderException,
                                InvalidAlgorithmParameterException,
                                InvalidKeyException,
                                SignatureException

Generates a signature for the string passed in

Parameters:

stringToSign - the string to be signed

privateKey - the private key to use for signing

algorithm - the Amazon Signature Algorithm from payConfiguration

Returns:

the signature

Throws:

NoSuchAlgorithmException - exception thrown when the cryptographic algorithm requested is not available in the environment

NoSuchProviderException - exception thrown when the security provider requested is not available in the environment

InvalidAlgorithmParameterException - exception for invalid algorithm parameters

InvalidKeyException - exception for invalid keys

SignatureException - signature exception

createPreSignedHeaders

public Map<String,List<String>> createPreSignedHeaders(URI uri,
                                                       Map<String,String> header)
                                                throws AmazonPayClientException

Creates the mandatory headers required in the request

Parameters:

uri - the uri to be executed

header - Map<String, String> containining key-value pair of required headers (e.g., keys such as x-amz-pay-idempotency-key, x-amz-pay-authtoken)

Returns:

a map of mandatory headers

Throws:

AmazonPayClientException - When an error response is returned by Amazon Pay due to bad request or other issue

getSignedHeadersString

public String getSignedHeadersString(Map<String,List<String>> preSignedHeaders)

Generates a string that is a list of headers names that are included in the canonical headers. This is to identify which headers are a part of the signing process.

Parameters:

preSignedHeaders - the mandatory header

Returns:

the string of signed headers

getCanonicalizedHeaderString

public String getCanonicalizedHeaderString(Map<String,List<String>> preSignedHeaders)

Generates a canonical headers string that consists of a list of all HTTP headers that are included with the request.

Parameters:

preSignedHeaders - the mandatory headers

Returns:

the canonical header string

getCanonicalizedQueryString

public String getCanonicalizedQueryString(Map<String,List<String>> parameters)
                                   throws AmazonPayClientException

Generates a canonical string that consists of all the query parameters

Parameters:

parameters - the query parameters of the request

Returns:

the canonical query string

Throws:

AmazonPayClientException - When an error response is returned by Amazon Pay due to bad request or other issue