Add lookup methods for crypto_auth_hmacsha256 constants

src/libsodium/Makefile.am

@@ -4,6 +4,7 @@ lib_LTLIBRARIES = \
 
 libsodium_la_SOURCES = \
 	crypto_auth/crypto_auth.c \
+	crypto_auth/hmacsha256/auth_hmacsha256.c \
 	crypto_auth/hmacsha256/ref/api.h \
 	crypto_auth/hmacsha256/ref/hmac_hmacsha256.c \
 	crypto_auth/hmacsha256/ref/verify_hmacsha256.c \

src/libsodium/crypto_auth/hmacsha256/auth_hmacsha256.c

@@ -0,0 +1,17 @@
+#include <stdlib.h>
+#include "crypto_auth_hmacsha256.h"
+
+size_t
+crypto_auth_hmacsha256_bytes(void) {
+    return crypto_auth_hmacsha256_BYTES;
+}
+
+size_t
+crypto_auth_hmacsha256_keybytes(void) {
+    return crypto_auth_hmacsha256_BYTES;
+}
+
+const char *
+crypto_auth_hmacsha256_primitive(void) {
+    return "hmacsha256";
+}

src/libsodium/include/sodium/crypto_auth_hmacsha256.h

@@ -1,6 +1,8 @@
 #ifndef crypto_auth_hmacsha256_H
 #define crypto_auth_hmacsha256_H
 
+#include <stdlib.h>
+
 #include "export.h"
 
 #define crypto_auth_hmacsha256_BYTES 32U
@@ -10,6 +12,15 @@
 extern "C" {
 #endif
 
+SODIUM_EXPORT
+size_t crypto_auth_hmacsha256_bytes(void);
+
+SODIUM_EXPORT
+size_t crypto_auth_hmacsha256_keybytes(void);
+
+SODIUM_EXPORT
+const char *crypto_auth_hmacsha256_primitive(void);
+
 SODIUM_EXPORT
 int crypto_auth_hmacsha256(unsigned char *,const unsigned char *,unsigned long long,const unsigned char *);