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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
commit | 1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5 (patch) | |
tree | 6cf8220b628ebd2ccfc1375dd6516c6996e9abcc /lib/verity/rs.h | |
parent | Initial commit. (diff) | |
download | cryptsetup-upstream.tar.xz cryptsetup-upstream.zip |
Adding upstream version 2:2.6.1.upstream/2%2.6.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/verity/rs.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/lib/verity/rs.h b/lib/verity/rs.h new file mode 100644 index 0000000..7638924 --- /dev/null +++ b/lib/verity/rs.h @@ -0,0 +1,63 @@ +/* + * Reed-Solomon codecs, based on libfec + * + * Copyright (C) 2004 Phil Karn, KA9Q + * libcryptsetup modifications + * Copyright (C) 2017-2023 Red Hat, Inc. All rights reserved. + * + * This file is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This file is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef _LIBFEC_RS_H +#define _LIBFEC_RS_H + +/* Special reserved value encoding zero in index form. */ +#define A0 (rs->nn) + +#define RS_MIN(a, b) ((a) < (b) ? (a) : (b)) + +typedef unsigned char data_t; + +/* Reed-Solomon codec control block */ +struct rs { + int mm; /* Bits per symbol */ + int nn; /* Symbols per block (= (1<<mm)-1) */ + data_t *alpha_to;/* log lookup table */ + data_t *index_of;/* Antilog lookup table */ + data_t *genpoly; /* Generator polynomial */ + int nroots; /* Number of generator roots = number of parity symbols */ + int fcr; /* First consecutive root, index form */ + int prim; /* Primitive element, index form */ + int iprim; /* prim-th root of 1, index form */ + int pad; /* Padding bytes in shortened block */ +}; + +static inline int modnn(struct rs *rs, int x) +{ + while (x >= rs->nn) { + x -= rs->nn; + x = (x >> rs->mm) + (x & rs->nn); + } + return x; +} + +struct rs *init_rs_char(int symsize, int gfpoly, int fcr, int prim, int nroots, int pad); +void free_rs_char(struct rs *rs); + +/* General purpose RS codec, 8-bit symbols */ +void encode_rs_char(struct rs *rs, data_t *data, data_t *parity); +int decode_rs_char(struct rs *rs, data_t *data); + +#endif |