diff -r a967ed801b0a -r 2e45aee0af19 libpurple/cipher.h
--- a/libpurple/cipher.h	Sat Jun 29 17:03:23 2013 +0530
+++ b/libpurple/cipher.h	Sat Jun 29 19:00:03 2013 +0530
@@ -132,32 +132,172 @@
 
 G_BEGIN_DECLS
 
+/*****************************************************************************/
+/** @name PurpleCipher API													 */
+/*****************************************************************************/
+/*@{*/
+
+/**
+ * Returns the GType for the Cipher object.
+ */
 GType purple_cipher_get_type(void);
 
+/**
+ * Gets a cipher's name
+ *
+ * @param cipher The cipher
+ *
+ * @return The cipher's name
+ */
 const gchar *purple_cipher_get_name(PurpleCipher *cipher);
 
+/**
+ * Resets a cipher to it's default value
+ * @note If you have set an IV you will have to set it after resetting
+ *
+ * @param cipher  The cipher
+ */
 void purple_cipher_reset(PurpleCipher *cipher);
+
+/**
+ * Resets a cipher state to it's default value, but doesn't touch stateless
+ * configuration.
+ *
+ * That means, IV and digest will be wiped out, but keys, ops or salt
+ * will remain untouched.
+ *
+ * @param cipher  The cipher
+ */
 void purple_cipher_reset_state(PurpleCipher *cipher);
+
+/**
+ * Sets the initialization vector for a cipher
+ * @note This should only be called right after a cipher is created or reset
+ *
+ * @param cipher  The cipher
+ * @param iv      The initialization vector to set
+ * @param len     The len of the IV
+ */
 void purple_cipher_set_iv(PurpleCipher *cipher, guchar *iv, size_t len);
 
+/**
+ * Appends data to the cipher context
+ *
+ * @param cipher  The cipher
+ * @param data    The data to append
+ * @param len     The length of the data
+ */
 void purple_cipher_append(PurpleCipher *cipher, const guchar *data, size_t len);
+
+/**
+ * Digests a cipher context
+ *
+ * @param cipher  The cipher
+ * @param digest  The return buffer for the digest
+ * @param len     The length of the buffer
+ */
 gboolean purple_cipher_digest(PurpleCipher *cipher, guchar digest[], size_t len);
+
+/**
+ * Converts a guchar digest into a hex string
+ *
+ * @param cipher   The cipher
+ * @param digest_s The return buffer for the string digest
+ * @param len      The length of the buffer
+ */
 gboolean purple_cipher_digest_to_str(PurpleCipher *cipher, gchar digest_s[], size_t len);
+
+/**
+ * Gets the digest size of a cipher
+ *
+ * @param cipher The cipher whose digest size to get
+ *
+ * @return The digest size of the cipher
+ */
 size_t purple_cipher_get_digest_size(PurpleCipher *cipher);
 
+/**
+ * Encrypts data using the cipher
+ *
+ * @param cipher   The cipher
+ * @param input    The data to encrypt
+ * @param in_len   The length of the data
+ * @param output   The output buffer
+ * @param out_size The size of the output buffer
+ *
+ * @return A length of data that was outputed or -1, if failed
+ */
 ssize_t purple_cipher_encrypt(PurpleCipher *cipher, const guchar input[], size_t in_len, guchar output[], size_t out_size);
+
+/**
+ * Decrypts data using the cipher
+ *
+ * @param cipher   The cipher
+ * @param input    The data to encrypt
+ * @param in_len   The length of the returned value
+ * @param output   The output buffer
+ * @param out_size The size of the output buffer
+ *
+ * @return A length of data that was outputed or -1, if failed
+ */
 ssize_t purple_cipher_decrypt(PurpleCipher *cipher, const guchar input[], size_t in_len, guchar output[], size_t out_size);
 
+/**
+ * Sets the salt on a cipher
+ *
+ * @param cipher  The cipher whose salt to set
+ * @param salt    The salt
+ * @param len     The length of the salt
+ */
 void purple_cipher_set_salt(PurpleCipher *cipher, const guchar *salt, size_t len);
 
+/**
+ * Sets the key on a cipher
+ *
+ * @param cipher  The cipher whose key to set
+ * @param key     The key
+ * @param len     The size of the key
+ */
 void purple_cipher_set_key(PurpleCipher *cipher, const guchar *key, size_t len);
+
+/**
+ * Gets the size of the key if the cipher supports it
+ *
+ * @param cipher The cipher whose key size to get
+ *
+ * @return The size of the key
+ */
 size_t purple_cipher_get_key_size(PurpleCipher *cipher);
 
+/**
+ * Sets the batch mode of a cipher
+ *
+ * @param cipher  The cipher whose batch mode to set
+ * @param mode    The batch mode under which the cipher should operate
+ *
+ */
 void purple_cipher_set_batch_mode(PurpleCipher *cipher, PurpleCipherBatchMode mode);
+
+/**
+ * Gets the batch mode of a cipher
+ *
+ * @param cipher The cipher whose batch mode to get
+ *
+ * @return The batch mode under which the cipher is operating
+ */
 PurpleCipherBatchMode purple_cipher_get_batch_mode(PurpleCipher *cipher);
 
+/**
+ * Gets the block size of a cipher
+ *
+ * @param cipher The cipher whose block size to get
+ *
+ * @return The block size of the cipher
+ */
 size_t purple_cipher_get_block_size(PurpleCipher *cipher);
 
+/*@}*/
+
 G_END_DECLS
 
 #endif /* PURPLE_CIPHER_H */