- Added Doxygen source code documentation parts (donated by Fox-IT)
diff --git a/doxygen/input/doc_x509.h b/doxygen/input/doc_x509.h
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+/**
+ * @file
+ * X.509 module documentation file.
+ */
+
+/**
+ * @addtogroup x509_module X.509 module
+ *
+ * The X.509 module provides X.509 support which includes:
+ * - X.509 certificate (CRT) reading (see \c x509parse_crt() and
+ * \c x509parse_crtfile()).
+ * - X.509 certificate revocation list (CRL) reading (see \c x509parse_crl()
+ * and\c x509parse_crlfile()).
+ * - X.509 (RSA) private key reading (see \c x509parse_key() and
+ * \c x509parse_keyfile()).
+ * - X.509 certificate signature verification (see \c x509parse_verify())
+ *
+ * This module can be used to build a certificate authority (CA) chain and
+ * verify its signature. It is also used to get a (RSA) private key for signing
+ * and decryption.
+ */
