New AES and GHASH implementations using POWER8 crypto opcodes.

inc/bearssl_hash.h

@@ -1309,4 +1309,30 @@ void br_ghash_pclmul(void *y, const void *h, const void *data, size_t len);
  */
 br_ghash br_ghash_pclmul_get(void);
 
+/**
+ * \brief GHASH implementation using the POWER8 opcodes.
+ *
+ * This implementation is available only on POWER8 platforms (and later).
+ * To safely obtain a pointer to this function when supported (or 0
+ * otherwise), use `br_ghash_pwr8_get()`.
+ *
+ * \param y      the array to update.
+ * \param h      the GHASH key.
+ * \param data   the input data (may be `NULL` if `len` is zero).
+ * \param len    the input data length (in bytes).
+ */
+void br_ghash_pwr8(void *y, const void *h, const void *data, size_t len);
+
+/**
+ * \brief Obtain the `pwr8` GHASH implementation, if available.
+ *
+ * If the `pwr8` implementation was compiled in the library (depending
+ * on the compiler abilities) _and_ the local CPU appears to support the
+ * opcode, then this function will return a pointer to the
+ * `br_ghash_pwr8()` function. Otherwise, it will return `0`.
+ *
+ * \return  the `pwr8` GHASH implementation, or `0`.
+ */
+br_ghash br_ghash_pwr8_get(void);
+
 #endif