1 files changed, 49 insertions, 0 deletions
diff --git a/base/gscrypt1.h b/base/gscrypt1.h
new file mode 100644
index 00000000..d79c7295
--- /dev/null
+++ b/base/gscrypt1.h
@@ -0,0 +1,49 @@
+/* Copyright (C) 2001-2019 Artifex Software, Inc.
+   All Rights Reserved.
+
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   This software is distributed under license and may not be copied,
+   modified or distributed except as expressly authorized under the terms
+   of the license contained in the file LICENSE in this distribution.
+
+   Refer to licensing information at http://www.artifex.com or contact
+   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
+   CA 94945, U.S.A., +1(415)492-9861, for further information.
+*/
+
+
+/* Interface to Adobe Type 1 encryption/decryption. */
+
+#ifndef gscrypt1_INCLUDED
+#  define gscrypt1_INCLUDED
+
+#include "stdpre.h"
+
+/* Normal public interface */
+typedef ushort crypt_state;
+int gs_type1_encrypt(byte * dest, const byte * src, uint len,
+                     crypt_state * pstate);
+int gs_type1_decrypt(byte * dest, const byte * src, uint len,
+                     crypt_state * pstate);
+
+/* Define the encryption parameters and procedures. */
+#define crypt_c1 ((ushort)52845)
+#define crypt_c2 ((ushort)22719)
+/* c1 * c1' == 1 mod 2^16. */
+#define crypt_c1_inverse ((ushort)27493)
+#define encrypt_next(ch, state, chvar)\
+  (chvar = ((ch) ^ (state >> 8)),\
+   state = (chvar + state) * crypt_c1 + crypt_c2)
+#define decrypt_this(ch, state)\
+  ((ch) ^ (state >> 8))
+#define decrypt_next(ch, state, chvar)\
+  (chvar = decrypt_this(ch, state),\
+   decrypt_skip_next(ch, state))
+#define decrypt_skip_next(ch, state)\
+  (state = ((ch) + state) * crypt_c1 + crypt_c2)
+#define decrypt_skip_previous(ch, state)\
+  (state = (state - crypt_c2) * crypt_c1_inverse - (ch))
+
+#endif /* gscrypt1_INCLUDED */