Add crypto_hash_primitive()

src/libsodium/crypto_hash/crypto_hash.c

@@ -7,3 +7,8 @@ crypto_hash(unsigned char *out, const unsigned char *in,
 {
     return crypto_hash_sha512(out, in, inlen);
 }
+
+const char *
+crypto_hash_primitive(void) {
+    return crypto_hash_sha512_primitive();
+}

src/libsodium/include/sodium/crypto_hash.h

@@ -19,6 +19,9 @@ SODIUM_EXPORT
 int crypto_hash(unsigned char *out, const unsigned char *in,
                 unsigned long long inlen);
 
+SODIUM_EXPORT
+const char *crypto_hash_primitive(void);
+
 #ifdef __cplusplus
 }
 #endif