1 files changed, 12 insertions, 0 deletions
diff --git a/src/libbiguint/bu_submod.c b/src/libbiguint/bu_submod.c
new file mode 100644
index 0000000..f988a50
--- /dev/null
+++ b/src/libbiguint/bu_submod.c
@@ -0,0 +1,12 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/uint32.h>
+#include <skalibs/biguint.h>
+
+int bu_submod (uint32 *c, unsigned int cn, uint32 const *a, unsigned int an, uint32 const *b, unsigned int bn, uint32 const *m, unsigned int mn)
+{
+  if (!bu_sub(c, cn, a, an, b, bn) && bu_add(c, cn, c, cn, m, mn))
+    return (errno = EDOM, 0) ;
+  return (errno = 0, 1) ;
+}