1 files changed, 47 insertions, 0 deletions
diff --git a/filter/arc4filter.c b/filter/arc4filter.c
new file mode 100644
index 00000000..257462d8
--- /dev/null
+++ b/filter/arc4filter.c
@@ -0,0 +1,47 @@
+#include <fitz.h>
+
+typedef struct fz_arc4c_s fz_arc4c;
+
+struct fz_arc4c_s
+{
+	fz_filter super;
+	fz_arc4 arc4;
+};
+
+fz_error *
+fz_newarc4filter(fz_filter **fp, unsigned char *key, unsigned keylen)
+{
+	FZ_NEWFILTER(fz_arc4c, f, arc4filter);
+	fz_arc4init(&f->arc4, key, keylen);
+	return nil;
+}
+
+void
+fz_freearc4filter(fz_filter *f)
+{
+	fz_free(f);
+}
+
+fz_error *
+fz_processarc4filter(fz_filter *filter, fz_buffer *in, fz_buffer *out)
+{
+	fz_arc4c *f = (fz_arc4c*)filter;
+	int n;
+
+	while (1)
+	{
+		if (in->rp + 1 > in->wp) {
+			if (in->eof)
+				return fz_iodone;
+			return fz_ioneedin;
+		}
+		if (out->wp + 1 > out->ep)
+			return fz_ioneedout;
+
+		n = MIN(in->wp - in->rp, out->ep - out->wp);
+		fz_arc4encrypt(&f->arc4, out->wp, in->rp, n);
+		in->rp += n;
+		out->wp += n;
+	}
+}
+