1 files changed, 35 insertions, 0 deletions
diff --git a/libblake_decode_hex.c b/libblake_decode_hex.c
new file mode 100644
index 0000000..4243d82
--- /dev/null
+++ b/libblake_decode_hex.c
@@ -0,0 +1,35 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+size_t
+libblake_decode_hex(const char *data, size_t n, void *out_)
+{
+	unsigned char *out = out_, value;
+	size_t i, j = 0;
+	int odd = 0;
+
+	if (!out) {
+		for (i = 0; i < n && data[i]; i++) {
+			if (isxdigit(data[i])) {
+				j += (size_t)odd;
+				odd ^= 1;
+			}
+		}
+		return j;
+	}
+
+	for (i = 0; i < n && data[i]; i++) {
+		if (isxdigit(data[i])) {
+			value = (unsigned char)((data[i] & 15) + (data[i] > '9' ? 9 : 0));
+			if (!odd) {
+				out[j] = (unsigned char)(value << 4);
+				odd = 1;
+			} else {
+				out[j++] |= value;
+				odd = 0;
+			}
+		}
+	}
+
+	return j;
+}