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Diffstat (limited to 'src/libstrongswan/plugins/ntru/ntru_convert.h')
| -rw-r--r-- | src/libstrongswan/plugins/ntru/ntru_convert.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/ntru/ntru_convert.h b/src/libstrongswan/plugins/ntru/ntru_convert.h new file mode 100644 index 000000000..31594b1f6 --- /dev/null +++ b/src/libstrongswan/plugins/ntru/ntru_convert.h @@ -0,0 +1,147 @@ +/* + * Copyright (C) 2014 Andreas Steffen + * HSR Hochschule fuer Technik Rapperswil + * + * Copyright (C) 2009-2013 Security Innovation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program 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 General Public License + * for more details. + */ + +/** + * @defgroup ntru_convert ntru_convert + * @{ @ingroup ntru_p + */ + +#ifndef NTRU_CONVERT_H_ +#define NTRU_CONVERT_H_ + +#include <library.h> + +/** + * Each 3 bits in an array of octets is converted to 2 trits in an array + * of trits. + * + * @param octets pointer to array of octets + * @param num_trits number of trits to produce + * @param trits address for array of trits + */ +void ntru_bits_2_trits(uint8_t const *octets, uint16_t num_trits, + uint8_t *trits); + +/** + * Each 2 trits in an array of trits is converted to 3 bits, and the bits + * are packed in an array of octets. A multiple of 3 octets is output. + * Any bits in the final octets not derived from trits are zero. + * + * @param trits pointer to array of trits + * @param num_trits number of trits to convert + * @param octets address for array of octets + * @return TRUE if all trits were valid + * FALSE if invalid trits were found + */ +bool ntru_trits_2_bits(uint8_t const *trits, uint32_t num_trits, + uint8_t *octets); + +/** + * Takes an array of coefficients mod 4 and packs the results into an + * octet string. + * + * @param num_coeffs number of coefficients + * @param coeffs pointer to coefficients + * @param octets address for octets + */ +void ntru_coeffs_mod4_2_octets(uint16_t num_coeffs, uint16_t const *coeffs, + uint8_t *octets); + +/** + * Packs 5 trits in an octet, where a trit is 0, 1, or 2 (-1). + * + * @param trits pointer to trits + * @param octet address for octet + */ +void ntru_trits_2_octet(uint8_t const *trits, uint8_t *octet); + +/** + * Unpacks an octet to 5 trits, where a trit is 0, 1, or 2 (-1). + * + * @param octet octet to be unpacked + * @param trits address for trits + */ +void ntru_octet_2_trits(uint8_t octet, uint8_t *trits); + +/** + * + * Converts a list of the nonzero indices of a polynomial into an array of + * trits. + * + * @param in_len no. of indices + * @param in pointer to list of indices + * @param plus1 if list is +1 coefficients + * @param out address of output polynomial + */ +void ntru_indices_2_trits(uint16_t in_len, uint16_t const *in, bool plus1, + uint8_t *out); + +/** + * Unpacks an array of N trits and creates a list of array indices + * corresponding to trits = +1, and list of array indices corresponding to + * trits = -1. + * + * @param in pointer to packed-trit octets + * @param num_trits no. of packed trits + * @param indices_plus1 address for indices of +1 trits + * @param indices_minus1 address for indices of -1 trits + */ +void ntru_packed_trits_2_indices(uint8_t const *in, uint16_t num_trits, + uint16_t *indices_plus1, + uint16_t *indices_minus1); + +/** + * Takes a list of array indices corresponding to elements whose values + * are +1 or -1, and packs the N-element array of trits described by these + * lists into octets, 5 trits per octet. + * + * @param indices pointer to indices + * @param num_plus1 no. of indices for +1 trits + * @param num_minus1 no. of indices for -1 trits + * @param num_trits N, no. of trits in array + * @param buf temp buf, N octets + * @param out address for packed octet + */ +void ntru_indices_2_packed_trits(uint16_t const *indices, uint16_t num_plus1, + uint16_t num_minus1, uint16_t num_trits, + uint8_t *buf, uint8_t *out); + +/** + * Packs an array of n-bit elements into an array of + * ((in_len * n_bits) + 7) / 8 octets, 8 < n_bits < 16. + * + * @param in_len no. of elements to be packed + * @param in ptr to elements to be packed + * @param n_bits no. of bits in input element + * @param out addr for output octets + */ +void ntru_elements_2_octets(uint16_t in_len, uint16_t const *in, uint8_t n_bits, + uint8_t *out); + +/** + * Unpacks an octet string into an array of ((in_len * 8) / n_bits) + * n-bit elements, 8 < n < 16. Any extra bits are discarded. + * + * @param in_len no. of octets to be unpacked + * @param in ptr to octets to be unpacked + * @param n_bits no. of bits in output element + * @param out addr for output elements + */ +void ntru_octets_2_elements(uint16_t in_len, uint8_t const *in, uint8_t n_bits, + uint16_t *out); + +#endif /** NTRU_CONVERT_H_ @}*/ |