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>

include/rng.h

@@ -3,6 +3,8 @@
 #ifndef rng_h
 #define rng_h
 
+#include <sqisign_namespace.h>
+
 /**
  * Randombytes initialization.
  * Initialization may be needed for some random number generators (e.g. CTR-DRBG).
@@ -11,10 +13,22 @@
  * @param[in] personalization_string Personalization string
  * @param[in] security_strength Security string
  */
+SQISIGN_API
 void randombytes_init(unsigned char *entropy_input,
                       unsigned char *personalization_string,
                       int security_strength);
 
+/**
+ * Random byte generation using /dev/urandom.
+ * The caller is responsible to allocate sufficient memory to hold x.
+ *
+ * @param[out] x Memory to hold the random bytes.
+ * @param[in] xlen Number of random bytes to be generated
+ * @return int 0 on success, -1 otherwise
+ */
+SQISIGN_API
+int randombytes_select(unsigned char *x, unsigned long long xlen);
+
 /**
  * Random byte generation.
  * The caller is responsible to allocate sufficient memory to hold x.
@@ -23,6 +37,7 @@ void randombytes_init(unsigned char *entropy_input,
  * @param[in] xlen Number of random bytes to be generated
  * @return int 0 on success, -1 otherwise
  */
+SQISIGN_API
 int randombytes(unsigned char *x, unsigned long long xlen);
 
 #endif /* rng_h */