second-round version of SQIsign

Co-authored-by: Marius A. Aardal <marius.andre.aardal@gmail.com>
Co-authored-by: Gora Adj <gora.adj@tii.ae>
Co-authored-by: Diego F. Aranha <dfaranha@cs.au.dk>
Co-authored-by: Andrea Basso <sqisign@andreabasso.com>
Co-authored-by: Isaac Andrés Canales Martínez <icanalesm0500@gmail.com>
Co-authored-by: Jorge Chávez-Saab <jorgechavezsaab@gmail.com>
Co-authored-by: Maria Corte-Real Santos <mariascrsantos98@gmail.com>
Co-authored-by: Luca De Feo <github@defeo.lu>
Co-authored-by: Max Duparc <max.duparc@epfl.ch>
Co-authored-by: Jonathan Komada Eriksen <jonathan.eriksen97@gmail.com>
Co-authored-by: Décio Luiz Gazzoni Filho <decio@decpp.net>
Co-authored-by: Basil Hess <bhe@zurich.ibm.com>
Co-authored-by: Antonin Leroux <antonin.leroux@polytechnique.org>
Co-authored-by: Patrick Longa <plonga@microsoft.com>
Co-authored-by: Luciano Maino <mainoluciano.96@gmail.com>
Co-authored-by: Michael Meyer <michael@random-oracles.org>
Co-authored-by: Hiroshi Onuki <onuki@mist.i.u-tokyo.ac.jp>
Co-authored-by: Lorenz Panny <lorenz@yx7.cc>
Co-authored-by: Giacomo Pope <giacomopope@gmail.com>
Co-authored-by: Krijn Reijnders <reijnderskrijn@gmail.com>
Co-authored-by: Damien Robert <damien.robert@inria.fr>
Co-authored-by: Francisco Rodríguez-Henriquez <francisco.rodriguez@tii.ae>
Co-authored-by: Sina Schaeffler <sschaeffle@student.ethz.ch>
Co-authored-by: Benjamin Wesolowski <benjamin.wesolowski@ens-lyon.fr>

scripts/precomp/precompute_sizes.sage

@@ -0,0 +1,93 @@
+#!/usr/bin/env sage
+proof.all(False)  # faster
+
+from sage.misc.banner import require_version
+if not require_version(9, 8, print_message=True):
+    exit('')
+
+################################################################
+
+from parameters import lvl, f, p
+
+################################################################
+
+logp = ceil(log(p, 2))
+tors2val = (p+1).valuation(2)
+tors2part = (p+1).p_primary_part(2)
+tors3part = (p+1).p_primary_part(3)
+
+defs = dict()
+
+TORSION_2POWER_BYTES = (tors2part.bit_length() + 7) // 8
+SECURITY_BITS = round(p.bit_length() / 128) * 64
+RESPONSE_LENGTH = ceil(p.bit_length()/2)
+RESPONSE_BYTES = (RESPONSE_LENGTH + 9) // 8
+
+fpsz = (logp + 63)//64*8
+fp2sz = 2 * fpsz
+defs['SECURITY_BITS'] = SECURITY_BITS
+defs['SQIsign_response_length'] = ceil(logp/2)
+defs['HASH_ITERATIONS'] = 2**(32 * ceil( logp/64 ) - (tors2val - ceil(logp/2)))
+defs['FP_ENCODED_BYTES'] = fpsz
+defs['FP2_ENCODED_BYTES'] = fp2sz
+defs['EC_CURVE_ENCODED_BYTES'] = fp2sz  # just the A
+defs['EC_POINT_ENCODED_BYTES'] = fp2sz  # just the x
+defs['EC_BASIS_ENCODED_BYTES'] = 3 * defs['EC_POINT_ENCODED_BYTES']
+
+defs['PUBLICKEY_BYTES'] = defs['EC_CURVE_ENCODED_BYTES'] + 1  # extra byte for hint
+defs['SECRETKEY_BYTES'] = defs['PUBLICKEY_BYTES'] + 5*defs['FP_ENCODED_BYTES'] + 4*TORSION_2POWER_BYTES
+defs['SIGNATURE_BYTES'] = defs['EC_CURVE_ENCODED_BYTES'] + 2 + 4*RESPONSE_BYTES + (SECURITY_BITS//8) + 1 + 1
+
+size_privkey = defs['SECRETKEY_BYTES']
+size_pubkey = defs['PUBLICKEY_BYTES']
+size_signature = defs['SIGNATURE_BYTES']
+
+algname = f'SQIsign_lvl{lvl}'
+
+################################################################
+
+with open('include/encoded_sizes.h','w') as hfile:
+    for k,v in defs.items():
+        v = ZZ(v)
+        print(f'#define {k} {v}', file=hfile)
+
+################################################################
+
+api = f'''
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef api_h
+#define api_h
+
+#include <sqisign_namespace.h>
+
+#define CRYPTO_SECRETKEYBYTES {size_privkey}
+#define CRYPTO_PUBLICKEYBYTES {size_pubkey}
+#define CRYPTO_BYTES {size_signature}
+
+#define CRYPTO_ALGNAME "{algname}"
+
+#if defined(ENABLE_SIGN)
+SQISIGN_API
+int
+crypto_sign_keypair(unsigned char *pk, unsigned char *sk);
+
+SQISIGN_API
+int
+crypto_sign(unsigned char *sm, unsigned long long *smlen,
+            const unsigned char *m, unsigned long long mlen,
+            const unsigned char *sk);
+#endif
+
+SQISIGN_API
+int
+crypto_sign_open(unsigned char *m, unsigned long long *mlen,
+                 const unsigned char *sm, unsigned long long smlen,
+                 const unsigned char *pk);
+
+#endif /* api_h */
+'''.strip()
+
+with open(f'../../../nistapi/lvl{lvl}/api.h', 'w') as f:
+    print(api, file=f)
+