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07db9c1e60
pqcrypto/crypto_sign/falcon-512/clean/inner.h
Thom Wiggers 07db9c1e60 Put all common primitives on the heap (#266) 
* Put AES ctx on the heap

This forces people to use the ``ctx_release`` functions, because otherwise there will be leaks

* Put fips202 on the heap

* Add much more docs for fips202.h

* fixup! Put fips202 on the heap

* Put SHA2 on the heap-supporting API

* Fix clang-tidy warnings

* Fix unreachable free() in falcon

* Fix McEliece8192128f-sse GNU Makefile
2021-03-24 21:02:45 +00:00

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#ifndef FALCON_INNER_H__
#define FALCON_INNER_H__
/*
* Internal functions for Falcon. This is not the API intended to be
* used by applications; instead, this internal API provides all the
* primitives on which wrappers build to provide external APIs.
*
* ==========================(LICENSE BEGIN)============================
*
* Copyright (c) 2017-2019 Falcon Project
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* ===========================(LICENSE END)=============================
*
* @author Thomas Pornin <thomas.pornin@nccgroup.com>
*/
/*
* IMPORTANT API RULES
* -------------------
*
* This API has some non-trivial usage rules:
*
*
* - All public functions (i.e. the non-static ones) must be referenced
* with the PQCLEAN_FALCON512_CLEAN_ macro (e.g. PQCLEAN_FALCON512_CLEAN_verify_raw for the verify_raw()
* function). That macro adds a prefix to the name, which is
* configurable with the FALCON_PREFIX macro. This allows compiling
* the code into a specific "namespace" and potentially including
* several versions of this code into a single application (e.g. to
* have an AVX2 and a non-AVX2 variants and select the one to use at
* runtime based on availability of AVX2 opcodes).
*
* - Functions that need temporary buffers expects them as a final
* tmp[] array of type uint8_t*, with a size which is documented for
* each function. However, most have some alignment requirements,
* because they will use the array to store 16-bit, 32-bit or 64-bit
* values (e.g. uint64_t or double). The caller must ensure proper
* alignment. What happens on unaligned access depends on the
* underlying architecture, ranging from a slight time penalty
* to immediate termination of the process.
*
* - Some functions rely on specific rounding rules and precision for
* floating-point numbers. On some systems (in particular 32-bit x86
* with the 387 FPU), this requires setting an hardware control
* word. The caller MUST use set_fpu_cw() to ensure proper precision:
*
* oldcw = set_fpu_cw(2);
* PQCLEAN_FALCON512_CLEAN_sign_dyn(...);
* set_fpu_cw(oldcw);
*
* On systems where the native floating-point precision is already
* proper, or integer-based emulation is used, the set_fpu_cw()
* function does nothing, so it can be called systematically.
*/
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
/*
* Some computations with floating-point elements, in particular
* rounding to the nearest integer, rely on operations using _exactly_
* the precision of IEEE-754 binary64 type (i.e. 52 bits). On 32-bit
* x86, the 387 FPU may be used (depending on the target OS) and, in
* that case, may use more precision bits (i.e. 64 bits, for an 80-bit
* total type length); to prevent miscomputations, we define an explicit
* function that modifies the precision in the FPU control word.
*
* set_fpu_cw() sets the precision to the provided value, and returns
* the previously set precision; callers are supposed to restore the
* previous precision on exit. The correct (52-bit) precision is
* configured with the value "2". On unsupported compilers, or on
* targets other than 32-bit x86, or when the native 'double' type is
* not used, the set_fpu_cw() function does nothing at all.
*/
static inline unsigned
set_fpu_cw(unsigned x) {
return x;
}
/* ==================================================================== */
/*
* SHAKE256 implementation (shake.c).
*
* API is defined to be easily replaced with the fips202.h API defined
* as part of PQClean.
*/
#include "fips202.h"
#define inner_shake256_context shake256incctx
#define inner_shake256_init(sc) shake256_inc_init(sc)
#define inner_shake256_inject(sc, in, len) shake256_inc_absorb(sc, in, len)
#define inner_shake256_flip(sc) shake256_inc_finalize(sc)
#define inner_shake256_extract(sc, out, len) shake256_inc_squeeze(out, len, sc)
#define inner_shake256_ctx_release(sc) shake256_inc_ctx_release(sc)
/* ==================================================================== */
/*
* Encoding/decoding functions (codec.c).
*
* Encoding functions take as parameters an output buffer (out) with
* a given maximum length (max_out_len); returned value is the actual
* number of bytes which have been written. If the output buffer is
* not large enough, then 0 is returned (some bytes may have been
* written to the buffer). If 'out' is NULL, then 'max_out_len' is
* ignored; instead, the function computes and returns the actual
* required output length (in bytes).
*
* Decoding functions take as parameters an input buffer (in) with
* its maximum length (max_in_len); returned value is the actual number
* of bytes that have been read from the buffer. If the provided length
* is too short, then 0 is returned.
*
* Values to encode or decode are vectors of integers, with N = 2^logn
* elements.
*
* Three encoding formats are defined:
*
* - modq: sequence of values modulo 12289, each encoded over exactly
* 14 bits. The encoder and decoder verify that integers are within
* the valid range (0..12288). Values are arrays of uint16.
*
* - trim: sequence of signed integers, a specified number of bits
* each. The number of bits is provided as parameter and includes
* the sign bit. Each integer x must be such that |x| < 2^(bits-1)
* (which means that the -2^(bits-1) value is forbidden); encode and
* decode functions check that property. Values are arrays of
* int16_t or int8_t, corresponding to names 'trim_i16' and
* 'trim_i8', respectively.
*
* - comp: variable-length encoding for signed integers; each integer
* uses a minimum of 9 bits, possibly more. This is normally used
* only for signatures.
*
*/
size_t PQCLEAN_FALCON512_CLEAN_modq_encode(void *out, size_t max_out_len,
const uint16_t *x, unsigned logn);
size_t PQCLEAN_FALCON512_CLEAN_trim_i16_encode(void *out, size_t max_out_len,
const int16_t *x, unsigned logn, unsigned bits);
size_t PQCLEAN_FALCON512_CLEAN_trim_i8_encode(void *out, size_t max_out_len,
const int8_t *x, unsigned logn, unsigned bits);
size_t PQCLEAN_FALCON512_CLEAN_comp_encode(void *out, size_t max_out_len,
const int16_t *x, unsigned logn);
size_t PQCLEAN_FALCON512_CLEAN_modq_decode(uint16_t *x, unsigned logn,
const void *in, size_t max_in_len);
size_t PQCLEAN_FALCON512_CLEAN_trim_i16_decode(int16_t *x, unsigned logn, unsigned bits,
const void *in, size_t max_in_len);
size_t PQCLEAN_FALCON512_CLEAN_trim_i8_decode(int8_t *x, unsigned logn, unsigned bits,
const void *in, size_t max_in_len);
size_t PQCLEAN_FALCON512_CLEAN_comp_decode(int16_t *x, unsigned logn,
const void *in, size_t max_in_len);
/*
* Number of bits for key elements, indexed by logn (1 to 10). This
* is at most 8 bits for all degrees, but some degrees may have shorter
* elements.
*/
extern const uint8_t PQCLEAN_FALCON512_CLEAN_max_fg_bits[];
extern const uint8_t PQCLEAN_FALCON512_CLEAN_max_FG_bits[];
/*
* Maximum size, in bits, of elements in a signature, indexed by logn
* (1 to 10). The size includes the sign bit.
*/
extern const uint8_t PQCLEAN_FALCON512_CLEAN_max_sig_bits[];
/* ==================================================================== */
/*
* Support functions used for both signature generation and signature
* verification (common.c).
*/
/*
* From a SHAKE256 context (must be already flipped), produce a new
* point. This is the non-constant-time version, which may leak enough
* information to serve as a stop condition on a brute force attack on
* the hashed message (provided that the nonce value is known).
*/
void PQCLEAN_FALCON512_CLEAN_hash_to_point_vartime(inner_shake256_context *sc,
uint16_t *x, unsigned logn);
/*
* From a SHAKE256 context (must be already flipped), produce a new
* point. The temporary buffer (tmp) must have room for 2*2^logn bytes.
* This function is constant-time but is typically more expensive than
* PQCLEAN_FALCON512_CLEAN_hash_to_point_vartime().
*
* tmp[] must have 16-bit alignment.
*/
void PQCLEAN_FALCON512_CLEAN_hash_to_point_ct(inner_shake256_context *sc,
uint16_t *x, unsigned logn, uint8_t *tmp);
/*
* Tell whether a given vector (2N coordinates, in two halves) is
* acceptable as a signature. This compares the appropriate norm of the
* vector with the acceptance bound. Returned value is 1 on success
* (vector is short enough to be acceptable), 0 otherwise.
*/
int PQCLEAN_FALCON512_CLEAN_is_short(const int16_t *s1, const int16_t *s2, unsigned logn);
/*
* Tell whether a given vector (2N coordinates, in two halves) is
* acceptable as a signature. Instead of the first half s1, this
* function receives the "saturated squared norm" of s1, i.e. the
* sum of the squares of the coordinates of s1 (saturated at 2^32-1
* if the sum exceeds 2^31-1).
*
* Returned value is 1 on success (vector is short enough to be
* acceptable), 0 otherwise.
*/
int PQCLEAN_FALCON512_CLEAN_is_short_half(uint32_t sqn, const int16_t *s2, unsigned logn);
/* ==================================================================== */
/*
* Signature verification functions (vrfy.c).
*/
/*
* Convert a public key to NTT + Montgomery format. Conversion is done
* in place.
*/
void PQCLEAN_FALCON512_CLEAN_to_ntt_monty(uint16_t *h, unsigned logn);
/*
* Internal signature verification code:
* c0[] contains the hashed nonce+message
* s2[] is the decoded signature
* h[] contains the public key, in NTT + Montgomery format
* logn is the degree log
* tmp[] temporary, must have at least 2*2^logn bytes
* Returned value is 1 on success, 0 on error.
*
* tmp[] must have 16-bit alignment.
*/
int PQCLEAN_FALCON512_CLEAN_verify_raw(const uint16_t *c0, const int16_t *s2,
const uint16_t *h, unsigned logn, uint8_t *tmp);
/*
* Compute the public key h[], given the private key elements f[] and
* g[]. This computes h = g/f mod phi mod q, where phi is the polynomial
* modulus. This function returns 1 on success, 0 on error (an error is
* reported if f is not invertible mod phi mod q).
*
* The tmp[] array must have room for at least 2*2^logn elements.
* tmp[] must have 16-bit alignment.
*/
int PQCLEAN_FALCON512_CLEAN_compute_public(uint16_t *h,
const int8_t *f, const int8_t *g, unsigned logn, uint8_t *tmp);
/*
* Recompute the fourth private key element. Private key consists in
* four polynomials with small coefficients f, g, F and G, which are
* such that fG - gF = q mod phi; furthermore, f is invertible modulo
* phi and modulo q. This function recomputes G from f, g and F.
*
* The tmp[] array must have room for at least 4*2^logn bytes.
*
* Returned value is 1 in success, 0 on error (f not invertible).
* tmp[] must have 16-bit alignment.
*/
int PQCLEAN_FALCON512_CLEAN_complete_private(int8_t *G,
const int8_t *f, const int8_t *g, const int8_t *F,
unsigned logn, uint8_t *tmp);
/*
* Test whether a given polynomial is invertible modulo phi and q.
* Polynomial coefficients are small integers.
*
* tmp[] must have 16-bit alignment.
*/
int PQCLEAN_FALCON512_CLEAN_is_invertible(
const int16_t *s2, unsigned logn, uint8_t *tmp);
/*
* Count the number of elements of value zero in the NTT representation
* of the given polynomial: this is the number of primitive 2n-th roots
* of unity (modulo q = 12289) that are roots of the provided polynomial
* (taken modulo q).
*
* tmp[] must have 16-bit alignment.
*/
int PQCLEAN_FALCON512_CLEAN_count_nttzero(const int16_t *sig, unsigned logn, uint8_t *tmp);
/*
* Internal signature verification with public key recovery:
* h[] receives the public key (NOT in NTT/Montgomery format)
* c0[] contains the hashed nonce+message
* s1[] is the first signature half
* s2[] is the second signature half
* logn is the degree log
* tmp[] temporary, must have at least 2*2^logn bytes
* Returned value is 1 on success, 0 on error. Success is returned if
* the signature is a short enough vector; in that case, the public
* key has been written to h[]. However, the caller must still
* verify that h[] is the correct value (e.g. with regards to a known
* hash of the public key).
*
* h[] may not overlap with any of the other arrays.
*
* tmp[] must have 16-bit alignment.
*/
int PQCLEAN_FALCON512_CLEAN_verify_recover(uint16_t *h,
const uint16_t *c0, const int16_t *s1, const int16_t *s2,
unsigned logn, uint8_t *tmp);
/* ==================================================================== */
/*
* Implementation of floating-point real numbers (fpr.h, fpr.c).
*/
/*
* Real numbers are implemented by an extra header file, included below.
* This is meant to support pluggable implementations. The default
* implementation relies on the C type 'double'.
*
* The included file must define the following types, functions and
* constants:
*
* fpr
* type for a real number
*
* fpr fpr_of(int64_t i)
* cast an integer into a real number; source must be in the
* -(2^63-1)..+(2^63-1) range
*
* fpr fpr_scaled(int64_t i, int sc)
* compute i*2^sc as a real number; source 'i' must be in the
* -(2^63-1)..+(2^63-1) range
*
* fpr fpr_ldexp(fpr x, int e)
* compute x*2^e
*
* int64_t fpr_rint(fpr x)
* round x to the nearest integer; x must be in the -(2^63-1)
* to +(2^63-1) range
*
* int64_t fpr_trunc(fpr x)
* round to an integer; this rounds towards zero; value must
* be in the -(2^63-1) to +(2^63-1) range
*
* fpr fpr_add(fpr x, fpr y)
* compute x + y
*
* fpr fpr_sub(fpr x, fpr y)
* compute x - y
*
* fpr fpr_neg(fpr x)
* compute -x
*
* fpr fpr_half(fpr x)
* compute x/2
*
* fpr fpr_double(fpr x)
* compute x*2
*
* fpr fpr_mul(fpr x, fpr y)
* compute x * y
*
* fpr fpr_sqr(fpr x)
* compute x * x
*
* fpr fpr_inv(fpr x)
* compute 1/x
*
* fpr fpr_div(fpr x, fpr y)
* compute x/y
*
* fpr fpr_sqrt(fpr x)
* compute the square root of x
*
* int fpr_lt(fpr x, fpr y)
* return 1 if x < y, 0 otherwise
*
* uint64_t fpr_expm_p63(fpr x)
* return exp(x), assuming that 0 <= x < log(2). Returned value
* is scaled to 63 bits (i.e. it really returns 2^63*exp(-x),
* rounded to the nearest integer). Computation should have a
* precision of at least 45 bits.
*
* const fpr fpr_gm_tab[]
* array of constants for FFT / iFFT
*
* const fpr fpr_p2_tab[]
* precomputed powers of 2 (by index, 0 to 10)
*
* Constants of type 'fpr':
*
* fpr fpr_q 12289
* fpr fpr_inverse_of_q 1/12289
* fpr fpr_inv_2sqrsigma0 1/(2*(1.8205^2))
* fpr fpr_inv_sigma 1/(1.55*sqrt(12289))
* fpr fpr_sigma_min_9 1.291500756233514568549480827642
* fpr fpr_sigma_min_10 1.311734375905083682667395805765
* fpr fpr_log2 log(2)
* fpr fpr_inv_log2 1/log(2)
* fpr fpr_bnorm_max 16822.4121
* fpr fpr_zero 0
* fpr fpr_one 1
* fpr fpr_two 2
* fpr fpr_onehalf 0.5
* fpr fpr_ptwo31 2^31
* fpr fpr_ptwo31m1 2^31-1
* fpr fpr_mtwo31m1 -(2^31-1)
* fpr fpr_ptwo63m1 2^63-1
* fpr fpr_mtwo63m1 -(2^63-1)
* fpr fpr_ptwo63 2^63
*/
#include "fpr.h"
/* ==================================================================== */
/*
* RNG (rng.c).
*
* A PRNG based on ChaCha20 is implemented; it is seeded from a SHAKE256
* context (flipped) and is used for bulk pseudorandom generation.
* A system-dependent seed generator is also provided.
*/
/*
* Obtain a random seed from the system RNG.
*
* Returned value is 1 on success, 0 on error.
*/
int PQCLEAN_FALCON512_CLEAN_get_seed(void *seed, size_t seed_len);
/*
* Structure for a PRNG. This includes a large buffer so that values
* get generated in advance. The 'state' is used to keep the current
* PRNG algorithm state (contents depend on the selected algorithm).
*
* The unions with 'dummy_u64' are there to ensure proper alignment for
* 64-bit direct access.
*/
typedef struct {
union {
uint8_t d[512]; /* MUST be 512, exactly */
uint64_t dummy_u64;
} buf;
size_t ptr;
union {
uint8_t d[256];
uint64_t dummy_u64;
} state;
int type;
} prng;
/*
* Instantiate a PRNG. That PRNG will feed over the provided SHAKE256
* context (in "flipped" state) to obtain its initial state.
*/
void PQCLEAN_FALCON512_CLEAN_prng_init(prng *p, inner_shake256_context *src);
/*
* Refill the PRNG buffer. This is normally invoked automatically, and
* is declared here only so that prng_get_u64() may be inlined.
*/
void PQCLEAN_FALCON512_CLEAN_prng_refill(prng *p);
/*
* Get some bytes from a PRNG.
*/
void PQCLEAN_FALCON512_CLEAN_prng_get_bytes(prng *p, void *dst, size_t len);
/*
* Get a 64-bit random value from a PRNG.
*/
static inline uint64_t
prng_get_u64(prng *p) {
size_t u;
/*
* If there are less than 9 bytes in the buffer, we refill it.
* This means that we may drop the last few bytes, but this allows
* for faster extraction code. Also, it means that we never leave
* an empty buffer.
*/
u = p->ptr;
if (u >= (sizeof p->buf.d) - 9) {
PQCLEAN_FALCON512_CLEAN_prng_refill(p);
u = 0;
}
p->ptr = u + 8;
/*
* On systems that use little-endian encoding and allow
* unaligned accesses, we can simply read the data where it is.
*/
return (uint64_t)p->buf.d[u + 0]
| ((uint64_t)p->buf.d[u + 1] << 8)
| ((uint64_t)p->buf.d[u + 2] << 16)
| ((uint64_t)p->buf.d[u + 3] << 24)
| ((uint64_t)p->buf.d[u + 4] << 32)
| ((uint64_t)p->buf.d[u + 5] << 40)
| ((uint64_t)p->buf.d[u + 6] << 48)
| ((uint64_t)p->buf.d[u + 7] << 56);
}
/*
* Get an 8-bit random value from a PRNG.
*/
static inline unsigned
prng_get_u8(prng *p) {
unsigned v;
v = p->buf.d[p->ptr ++];
if (p->ptr == sizeof p->buf.d) {
PQCLEAN_FALCON512_CLEAN_prng_refill(p);
}
return v;
}
/* ==================================================================== */
/*
* FFT (falcon-fft.c).
*
* A real polynomial is represented as an array of N 'fpr' elements.
* The FFT representation of a real polynomial contains N/2 complex
* elements; each is stored as two real numbers, for the real and
* imaginary parts, respectively. See falcon-fft.c for details on the
* internal representation.
*/
/*
* Compute FFT in-place: the source array should contain a real
* polynomial (N coefficients); its storage area is reused to store
* the FFT representation of that polynomial (N/2 complex numbers).
*
* 'logn' MUST lie between 1 and 10 (inclusive).
*/
void PQCLEAN_FALCON512_CLEAN_FFT(fpr *f, unsigned logn);
/*
* Compute the inverse FFT in-place: the source array should contain the
* FFT representation of a real polynomial (N/2 elements); the resulting
* real polynomial (N coefficients of type 'fpr') is written over the
* array.
*
* 'logn' MUST lie between 1 and 10 (inclusive).
*/
void PQCLEAN_FALCON512_CLEAN_iFFT(fpr *f, unsigned logn);
/*
* Add polynomial b to polynomial a. a and b MUST NOT overlap. This
* function works in both normal and FFT representations.
*/
void PQCLEAN_FALCON512_CLEAN_poly_add(fpr *a, const fpr *b, unsigned logn);
/*
* Subtract polynomial b from polynomial a. a and b MUST NOT overlap. This
* function works in both normal and FFT representations.
*/
void PQCLEAN_FALCON512_CLEAN_poly_sub(fpr *a, const fpr *b, unsigned logn);
/*
* Negate polynomial a. This function works in both normal and FFT
* representations.
*/
void PQCLEAN_FALCON512_CLEAN_poly_neg(fpr *a, unsigned logn);
/*
* Compute adjoint of polynomial a. This function works only in FFT
* representation.
*/
void PQCLEAN_FALCON512_CLEAN_poly_adj_fft(fpr *a, unsigned logn);
/*
* Multiply polynomial a with polynomial b. a and b MUST NOT overlap.
* This function works only in FFT representation.
*/
void PQCLEAN_FALCON512_CLEAN_poly_mul_fft(fpr *a, const fpr *b, unsigned logn);
/*
* Multiply polynomial a with the adjoint of polynomial b. a and b MUST NOT
* overlap. This function works only in FFT representation.
*/
void PQCLEAN_FALCON512_CLEAN_poly_muladj_fft(fpr *a, const fpr *b, unsigned logn);
/*
* Multiply polynomial with its own adjoint. This function works only in FFT
* representation.
*/
void PQCLEAN_FALCON512_CLEAN_poly_mulselfadj_fft(fpr *a, unsigned logn);
/*
* Multiply polynomial with a real constant. This function works in both
* normal and FFT representations.
*/
void PQCLEAN_FALCON512_CLEAN_poly_mulconst(fpr *a, fpr x, unsigned logn);
/*
* Divide polynomial a by polynomial b, modulo X^N+1 (FFT representation).
* a and b MUST NOT overlap.
*/
void PQCLEAN_FALCON512_CLEAN_poly_div_fft(fpr *a, const fpr *b, unsigned logn);
/*
* Given f and g (in FFT representation), compute 1/(f*adj(f)+g*adj(g))
* (also in FFT representation). Since the result is auto-adjoint, all its
* coordinates in FFT representation are real; as such, only the first N/2
* values of d[] are filled (the imaginary parts are skipped).
*
* Array d MUST NOT overlap with either a or b.
*/
void PQCLEAN_FALCON512_CLEAN_poly_invnorm2_fft(fpr *d,
const fpr *a, const fpr *b, unsigned logn);
/*
* Given F, G, f and g (in FFT representation), compute F*adj(f)+G*adj(g)
* (also in FFT representation). Destination d MUST NOT overlap with
* any of the source arrays.
*/
void PQCLEAN_FALCON512_CLEAN_poly_add_muladj_fft(fpr *d,
const fpr *F, const fpr *G,
const fpr *f, const fpr *g, unsigned logn);
/*
* Multiply polynomial a by polynomial b, where b is autoadjoint. Both
* a and b are in FFT representation. Since b is autoadjoint, all its
* FFT coefficients are real, and the array b contains only N/2 elements.
* a and b MUST NOT overlap.
*/
void PQCLEAN_FALCON512_CLEAN_poly_mul_autoadj_fft(fpr *a,
const fpr *b, unsigned logn);
/*
* Divide polynomial a by polynomial b, where b is autoadjoint. Both
* a and b are in FFT representation. Since b is autoadjoint, all its
* FFT coefficients are real, and the array b contains only N/2 elements.
* a and b MUST NOT overlap.
*/
void PQCLEAN_FALCON512_CLEAN_poly_div_autoadj_fft(fpr *a,
const fpr *b, unsigned logn);
/*
* Perform an LDL decomposition of an auto-adjoint matrix G, in FFT
* representation. On input, g00, g01 and g11 are provided (where the
* matrix G = [[g00, g01], [adj(g01), g11]]). On output, the d00, l10
* and d11 values are written in g00, g01 and g11, respectively
* (with D = [[d00, 0], [0, d11]] and L = [[1, 0], [l10, 1]]).
* (In fact, d00 = g00, so the g00 operand is left unmodified.)
*/
void PQCLEAN_FALCON512_CLEAN_poly_LDL_fft(const fpr *g00,
fpr *g01, fpr *g11, unsigned logn);
/*
* Perform an LDL decomposition of an auto-adjoint matrix G, in FFT
* representation. This is identical to poly_LDL_fft() except that
* g00, g01 and g11 are unmodified; the outputs d11 and l10 are written
* in two other separate buffers provided as extra parameters.
*/
void PQCLEAN_FALCON512_CLEAN_poly_LDLmv_fft(fpr *d11, fpr *l10,
const fpr *g00, const fpr *g01,
const fpr *g11, unsigned logn);
/*
* Apply "split" operation on a polynomial in FFT representation:
* f = f0(x^2) + x*f1(x^2), for half-size polynomials f0 and f1
* (polynomials modulo X^(N/2)+1). f0, f1 and f MUST NOT overlap.
*/
void PQCLEAN_FALCON512_CLEAN_poly_split_fft(fpr *f0, fpr *f1,
const fpr *f, unsigned logn);
/*
* Apply "merge" operation on two polynomials in FFT representation:
* given f0 and f1, polynomials moduo X^(N/2)+1, this function computes
* f = f0(x^2) + x*f1(x^2), in FFT representation modulo X^N+1.
* f MUST NOT overlap with either f0 or f1.
*/
void PQCLEAN_FALCON512_CLEAN_poly_merge_fft(fpr *f,
const fpr *f0, const fpr *f1, unsigned logn);
/* ==================================================================== */
/*
* Key pair generation.
*/
/*
* Required sizes of the temporary buffer (in bytes).
*
* This size is 28*2^logn bytes, except for degrees 2 and 4 (logn = 1
* or 2) where it is slightly greater.
*/
#define FALCON_KEYGEN_TEMP_1 136
#define FALCON_KEYGEN_TEMP_2 272
#define FALCON_KEYGEN_TEMP_3 224
#define FALCON_KEYGEN_TEMP_4 448
#define FALCON_KEYGEN_TEMP_5 896
#define FALCON_KEYGEN_TEMP_6 1792
#define FALCON_KEYGEN_TEMP_7 3584
#define FALCON_KEYGEN_TEMP_8 7168
#define FALCON_KEYGEN_TEMP_9 14336
#define FALCON_KEYGEN_TEMP_10 28672
/*
* Generate a new key pair. Randomness is extracted from the provided
* SHAKE256 context, which must have already been seeded and flipped.
* The tmp[] array must have suitable size (see FALCON_KEYGEN_TEMP_*
* macros) and be aligned for the uint32_t, uint64_t and fpr types.
*
* The private key elements are written in f, g, F and G, and the
* public key is written in h. Either or both of G and h may be NULL,
* in which case the corresponding element is not returned (they can
* be recomputed from f, g and F).
*
* tmp[] must have 64-bit alignment.
* This function uses floating-point rounding (see set_fpu_cw()).
*/
void PQCLEAN_FALCON512_CLEAN_keygen(inner_shake256_context *rng,
int8_t *f, int8_t *g, int8_t *F, int8_t *G, uint16_t *h,
unsigned logn, uint8_t *tmp);
/* ==================================================================== */
/*
* Signature generation.
*/
/*
* Expand a private key into the B0 matrix in FFT representation and
* the LDL tree. All the values are written in 'expanded_key', for
* a total of (8*logn+40)*2^logn bytes.
*
* The tmp[] array must have room for at least 48*2^logn bytes.
*
* tmp[] must have 64-bit alignment.
* This function uses floating-point rounding (see set_fpu_cw()).
*/
void PQCLEAN_FALCON512_CLEAN_expand_privkey(fpr *expanded_key,
const int8_t *f, const int8_t *g, const int8_t *F, const int8_t *G,
unsigned logn, uint8_t *tmp);
/*
* Compute a signature over the provided hashed message (hm); the
* signature value is one short vector. This function uses an
* expanded key (as generated by PQCLEAN_FALCON512_CLEAN_expand_privkey()).
*
* The sig[] and hm[] buffers may overlap.
*
* On successful output, the start of the tmp[] buffer contains the s1
* vector (as int16_t elements).
*
* The minimal size (in bytes) of tmp[] is 48*2^logn bytes.
*
* tmp[] must have 64-bit alignment.
* This function uses floating-point rounding (see set_fpu_cw()).
*/
void PQCLEAN_FALCON512_CLEAN_sign_tree(int16_t *sig, inner_shake256_context *rng,
const fpr *expanded_key,
const uint16_t *hm, unsigned logn, uint8_t *tmp);
/*
* Compute a signature over the provided hashed message (hm); the
* signature value is one short vector. This function uses a raw
* key and dynamically recompute the B0 matrix and LDL tree; this
* saves RAM since there is no needed for an expanded key, but
* increases the signature cost.
*
* The sig[] and hm[] buffers may overlap.
*
* On successful output, the start of the tmp[] buffer contains the s1
* vector (as int16_t elements).
*
* The minimal size (in bytes) of tmp[] is 72*2^logn bytes.
*
* tmp[] must have 64-bit alignment.
* This function uses floating-point rounding (see set_fpu_cw()).
*/
void PQCLEAN_FALCON512_CLEAN_sign_dyn(int16_t *sig, inner_shake256_context *rng,
const int8_t *f, const int8_t *g,
const int8_t *F, const int8_t *G,
const uint16_t *hm, unsigned logn, uint8_t *tmp);
/*
* Internal sampler engine. Exported for tests.
*
* sampler_context wraps around a source of random numbers (PRNG) and
* the sigma_min value (nominally dependent on the degree).
*
* sampler() takes as parameters:
* ctx pointer to the sampler_context structure
* mu center for the distribution
* isigma inverse of the distribution standard deviation
* It returns an integer sampled along the Gaussian distribution centered
* on mu and of standard deviation sigma = 1/isigma.
*
* gaussian0_sampler() takes as parameter a pointer to a PRNG, and
* returns an integer sampled along a half-Gaussian with standard
* deviation sigma0 = 1.8205 (center is 0, returned value is
* nonnegative).
*/
typedef struct {
prng p;
fpr sigma_min;
} sampler_context;
int PQCLEAN_FALCON512_CLEAN_sampler(void *ctx, fpr mu, fpr isigma);
int PQCLEAN_FALCON512_CLEAN_gaussian0_sampler(prng *p);
/* ==================================================================== */
#endif
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