+#ifndef PPP_SHA1_H
+#define PPP_SHA1_H
+
+#include "pppdconf.h"
+
+#ifndef USE_SHA
+#include <openssl/sha.h>
+
+#define SHA1_CTX SHA_CTX
+#define SHA1_SIGNATURE_SIZE SHA_DIGEST_LENGTH
+
+#else
+
+#ifndef SHA1_SIGNATURE_SIZE
+#ifdef SHA_DIGESTSIZE
+#define SHA1_SIGNATURE_SIZE SHA_DIGESTSIZE
+#else
+#define SHA1_SIGNATURE_SIZE 20
+#endif
+#endif