Doc: generate_key: improve documentation of \p extra
@@ -2427,22 +2427,27 @@ typedef struct {
* \param[in] extra Extra parameters for key generation. The
* interpretation of this parameter depends on
* \c type. All types support \c NULL to use
- * the default parameters specified below.
+ * default parameters. Implementation that support
+ * the generation of vendor-specific key types
+ * that allow extra parameters shall document
+ * the format of these extra parameters and
+ * the default values. For standard parameters,
+ * the meaning of \p extra is as follows:
+ * - For a symmetric key type (a type \c type such
+ * that #PSA_KEY_TYPE_IS_ASYMMETRIC(\p type) is
+ * false), \p extra must be \c NULL.
+ * - For an elliptic curve key type (a type \c type
+ * such that #PSA_KEY_TYPE_IS_ECC(\p type) is
+ * false), \p extra must be \c NULL.
+ * - For an RSA key, \p extra is an optional
+ * #psa_generate_key_extra_rsa structure
+ * specifying the public exponent. The
+ * default public exponent used when \p extra
+ * is \c NULL is 65537.
* \param extra_size Size of the buffer that \p extra
* points to, in bytes. Note that if \p extra is
* \c NULL then \p extra_size must be zero.
*
- * For any symmetric key type (a type such that
- * #PSA_KEY_TYPE_IS_ASYMMETRIC(\p type) is false), \p extra must be
- * \c NULL. For asymmetric key types defined by this specification,
- * the parameter type and the default parameters are defined by the
- * table below. For vendor-defined key types, the vendor documentation
- * shall define the parameter type and the default parameters.
- *
- * Type | Parameter type | Meaning | Parameters used if `extra == NULL`
- * ---- | -------------- | ------- | ---------------------------------------
- * `PSA_KEY_TYPE_RSA_KEYPAIR` | #psa_generate_key_extra_rsa | Public exponent | 65537
- *
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_NOT_SUPPORTED
* \retval #PSA_ERROR_INVALID_ARGUMENT
