Allow Blake2s keys up to 32 bytes.

babeld.man

@@ -332,7 +332,7 @@ The
 .B value
 is a hexadecimal string (up to 64 bytes for
 .BR hmac-sha256 ,
-exactly 16 bytes for
+up to 32 bytes for
 .BR blake2s ).
 .SS Interface configuration
 An interface is configured by a line with the following format:

configuration.c

@@ -831,9 +831,9 @@ parse_key(int c, gnc_t gnc, void *closure, struct key **key_return)
         break;
     }
     case AUTH_TYPE_BLAKE2S:
-        if(key->len != 16) {
-            fprintf(stderr, "Key length is %d, expected %d.\n",
-                    key->len, 16);
+        if(key->len < 1 || key->len > 32) {
+            fprintf(stderr, "Key length is %d, expected 1 to 32.\n",
+                    key->len);
             goto error;
         }
         break;

hmac.c

@@ -173,7 +173,7 @@ compute_hmac(const unsigned char *src, const unsigned char *dst,
     }
     case AUTH_TYPE_BLAKE2S: {
         blake2s_state s;
-        if(key->len != 16)
+        if(key->len > 32)
             return -1;
         rc = blake2s_init_key(&s, 16, key->value, key->len);
         if(rc < 0)