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Diffstat (limited to 'gs/base/gscrypt1.h')
| -rw-r--r-- | gs/base/gscrypt1.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/gs/base/gscrypt1.h b/gs/base/gscrypt1.h new file mode 100644 index 000000000..db1bdf650 --- /dev/null +++ b/gs/base/gscrypt1.h @@ -0,0 +1,45 @@ +/* Copyright (C) 2001-2006 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 that + license. Refer to licensing information at http://www.artifex.com/ + or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134, + San Rafael, CA 94903, U.S.A., +1(415)492-9861, for further information. +*/ + +/* $Id$ */ +/* Interface to Adobe Type 1 encryption/decryption. */ + +#ifndef gscrypt1_INCLUDED +# define gscrypt1_INCLUDED + +/* 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 */ |