--- a/th_crypto.h	Fri Apr 07 02:49:08 2017 +0300
+++ b/th_crypto.h	Wed May 10 21:00:37 2017 +0300
@@ -7,6 +7,8 @@
  * written by Colin Plumb in 1993, no copyright is claimed.
  * This code is in the public domain; do with it what you wish.
  */
+/// @file
+/// @brief Cryptography and hash related functions
 #ifndef TH_CRYPTO_H
 #define TH_CRYPTO_H 1
 
@@ -22,17 +24,22 @@
 #endif
 
 
+/** @def MD5 digest related defines
+ */
 #define TH_MD5HASH_LENGTH       (16)
 #define TH_MD5HASH_LENGTH_CH    (TH_MD5HASH_LENGTH * 2)
 
+
+/** MD5 digest state structure
+ */
 typedef struct
 {
-    uint32_t bits[2];    // Message length in bits, lsw first
-    uint32_t buf[4];     // Digest buffer
-    uint8_t in[64];      // Accumulate block
+    uint32_t bits[2];    ///< Message length in bits, lsw first
+    uint32_t buf[4];     ///< Digest buffer
+    uint8_t in[64];      ///< Accumulate block
 } th_md5state_t;
 
-typedef uint8_t th_md5hash_t[TH_MD5HASH_LENGTH];
+typedef uint8_t th_md5hash_t[TH_MD5HASH_LENGTH]; ///< A structure containing MD5 digest hash
 
 
 void    th_md5_init(th_md5state_t *ctx);