Add enum class representing RSA parameters (to be used with JWKS).

Author: Potherca

src/Enum/Rsa/Parameter.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Pdsinterop\Solid\Auth\Enum\Rsa;
+
+/**
+ * Parameters for RSA Public Keys
+ *
+ * These members MUST be present for RSA public keys.
+ *
+ * The RSA Key blinding operation [Kocher], which is a defense against some
+ * timing attacks, requires all of the RSA key values "n", "e", and "d".
+ *
+ * However, some RSA private key representations do not include the public
+ * exponent "e", but only include the modulus "n" and the private exponent
+ * "d". This is true, for instance, of the Java RSAPrivateKeySpec API, which
+ * does not include the public exponent "e" as a parameter. So as to enable
+ * RSA key blinding, such representations should be avoided. For Java, the
+ * RSAPrivateCrtKeySpec API can be used instead. Section 8.2.2(i) of the
+ * "Handbook of Applied Cryptography" [HAC] discusses how to compute the
+ * remaining RSA private key parameters, if needed, using only "n", "e",
+ * and "d".}
+*
+ * @see https://tools.ietf.org/html/rfc7518#section-6.3
+ */
+class Parameter
+{
+    /**
+     * The "e" (exponent) parameter contains the exponent value for the RSA
+     * public key. It is represented as a Base64urlUInt-encoded value. For
+     * instance, when representing the value 65537, the octet sequence to be
+     * base64url-encoded MUST consist of the three octets [1, 0, 1]; the
+     * resulting representation for this value is "AQAB".
+     */
+    public const PUBLIC_EXPONENT = 'e';
+
+    /**
+     * The "n" (modulus) parameter contains the modulus value for the RSA public
+     * key.  It is represented as a Base64urlUInt-encoded value.
+     */
+    public const PUBLIC_MODULUS = 'n';
+
+    /**
+     * The "d" (private exponent) parameter contains the private exponent value
+     * for the RSA private key.  It is represented as a Base64urlUInt-encoded
+     * value.}
+     */
+    public const PRIVATE_EXPONENT = 'd';
+}