Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-zesty-kernel.git] / include / crypto / dh.h

diff --git a/include/crypto/dh.h b/include/crypto/dh.h
index 5102a8f282e606932fa5e447216da4efab06c31e..6b424ad3482e3c5662d05108ea8cb06298cca808 100644 (file)
--- a/include/crypto/dh.h
+++ b/include/crypto/dh.h
@@ -13,6 +13,27 @@
 #ifndef _CRYPTO_DH_
 #define _CRYPTO_DH_
 
+/**
+ * DOC: DH Helper Functions
+ *
+ * To use DH with the KPP cipher API, the following data structure and
+ * functions should be used.
+ *
+ * To use DH with KPP, the following functions should be used to operate on
+ * a DH private key. The packet private key that can be set with
+ * the KPP API function call of crypto_kpp_set_secret.
+ */
+
+/**
+ * struct dh - define a DH private key
+ *
+ * @key:       Private DH key
+ * @p:         Diffie-Hellman parameter P
+ * @g:         Diffie-Hellman generator G
+ * @key_size:  Size of the private DH key
+ * @p_size:    Size of DH parameter P
+ * @g_size:    Size of DH generator G
+ */
 struct dh {
        void *key;
        void *p;
@@ -22,8 +43,45 @@ struct dh {
        unsigned int g_size;
 };
 
+/**
+ * crypto_dh_key_len() - Obtain the size of the private DH key
+ * @params:    private DH key
+ *
+ * This function returns the packet DH key size. A caller can use that
+ * with the provided DH private key reference to obtain the required
+ * memory size to hold a packet key.
+ *
+ * Return: size of the key in bytes
+ */
 int crypto_dh_key_len(const struct dh *params);
+
+/**
+ * crypto_dh_encode_key() - encode the private key
+ * @buf:       Buffer allocated by the caller to hold the packet DH
+ *             private key. The buffer should be at least crypto_dh_key_len
+ *             bytes in size.
+ * @len:       Length of the packet private key buffer
+ * @params:    Buffer with the caller-specified private key
+ *
+ * The DH implementations operate on a packet representation of the private
+ * key.
+ *
+ * Return:     -EINVAL if buffer has insufficient size, 0 on success
+ */
 int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params);
+
+/**
+ * crypto_dh_decode_key() - decode a private key
+ * @buf:       Buffer holding a packet key that should be decoded
+ * @len:       Lenth of the packet private key buffer
+ * @params:    Buffer allocated by the caller that is filled with the
+ *             unpacket DH private key.
+ *
+ * The unpacking obtains the private key by pointing @p to the correct location
+ * in @buf. Thus, both pointers refer to the same memory.
+ *
+ * Return:     -EINVAL if buffer has insufficient size, 0 on success
+ */
 int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params);
 
 #endif