diff --git a/digest/md5.h b/digest/md5.h
new file mode 100644
index 0000000..d997e37
--- /dev/null
+++ b/digest/md5.h
@@ -0,0 +1,29 @@
+#ifndef MD5_H
+#define MD5_H
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#else
+typedef unsigned int uint32_t;
+#endif
+
+#define MD5LENGTH 16
+
+struct MD5Context {
+	uint32_t buf[4];
+	uint32_t bits[2];
+	unsigned char in[64];
+};
+
+void MD5Init(struct MD5Context *context);
+void MD5Update(struct MD5Context *context, unsigned char const *buf,
+	       unsigned len);
+void MD5Final(unsigned char digest[MD5LENGTH], struct MD5Context *context);
+void MD5Transform(uint32_t buf[4], uint32_t const in[16]);
+
+/*
+ * This is needed to make RSAREF happy on some MS-DOS compilers.
+ */
+typedef struct MD5Context MD5_CTX;
+
+#endif /* !MD5_H */