sha3.[hc]: add sha3_backend()

2 files changed, 26 insertions, 1 deletions

diff --git a/sha3.c b/sha3.c
index 26ac022..6b4c2fd 100644
--- a/sha3.c
+++ b/sha3.c
@@ -751,7 +751,6 @@ static inline size_t absorb12(sha3_state_t * const a, size_t num_bytes, const si
   return num_bytes;
 }
 
-
 // Get rate (number of bytes that can be absorbed before the internal
 // state is permuted).
 //
@@ -2094,6 +2093,15 @@ void k12_once(const uint8_t *src, const size_t src_len, uint8_t *dst, const size
   k12_custom_once(src, src_len, NULL, 0, dst, dst_len);
 }
 
+// Return backend name.
+const char *sha3_backend(void) {
+#if SHA3_BACKEND == SHA3_BACKEND_AVX512
+  return "avx512";
+#elif SHA3_BACKEND == SHA3_BACKEND_SCALAR
+  return "scalar";
+#endif /* SHA3_BACKEND */
+}
+
 #ifdef SHA3_TEST
 #include <stdio.h> // printf()
 #include <stdlib.h> // malloc() (used in test_kangarootwelve())
diff --git a/sha3.h b/sha3.h
index c9b6f44..1937b26 100644
--- a/sha3.h
+++ b/sha3.h
@@ -2352,6 +2352,23 @@ void k12_init(k12_t *k12, const uint8_t *src, const size_t src_len, const uint8_
  */
 void k12_squeeze(k12_t *k12, uint8_t *dst, const size_t len);
 
+/**
+ * @defgroup misc Miscellaneous
+ * @brief Miscellaneous functions.
+ */
+
+/**
+ * @brief Get name of backend.
+ * @ingroup misc
+ *
+ * @note Returns a read-only string which much not be freed by the
+ * caller.
+ *
+ * Example:
+ * @snippet{trimleft} 06-all/all-fns.c sha3_backend
+ */
+const char *sha3_backend(void);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */