initial version of SQIsign

Co-authored-by: Jorge Chavez-Saab <jorgechavezsaab@gmail.com>
Co-authored-by: Maria Corte-Real Santos <36373796+mariascrs@users.noreply.github.com>
Co-authored-by: Luca De Feo <github@defeo.lu>
Co-authored-by: Jonathan Komada Eriksen <jonathan.eriksen97@gmail.com>
Co-authored-by: Basil Hess <bhe@zurich.ibm.com>
Co-authored-by: Antonin Leroux <18654258+tonioecto@users.noreply.github.com>
Co-authored-by: Patrick Longa <plonga@microsoft.com>
Co-authored-by: Lorenz Panny <lorenz@yx7.cc>
Co-authored-by: Francisco Rodríguez-Henríquez <francisco.rodriguez@tii.ae>
Co-authored-by: Sina Schaeffler <108983332+syndrakon@users.noreply.github.com>
Co-authored-by: Benjamin Wesolowski <19474926+Calodeon@users.noreply.github.com>

include/mem.h

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef MEM_H
+#define MEM_H
+#include <stddef.h>
+
+/**
+ * Clears and frees allocated memory.
+ * 
+ * @param[out] mem Memory to be cleared and freed.
+ * @param size Size of memory to be cleared and freed.
+ */
+void sqisign_secure_free(void *mem, size_t size);
+
+/**
+ * Clears memory.
+ * 
+ * @param[out] mem Memory to be cleared.
+ * @param size Size of memory to be cleared.
+ */
+void sqisign_secure_clear(void *mem, size_t size);
+
+#endif

include/rng.h

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+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef rng_h
+#define rng_h
+
+/**
+ * Randombytes initialization.
+ * Initialization may be needed for some random number generators (e.g. CTR-DRBG).
+ *
+ * @param[in] entropy_input 48 bytes entropy input
+ * @param[in] personalization_string Personalization string
+ * @param[in] security_strength Security string
+ */
+void randombytes_init(unsigned char *entropy_input,
+                      unsigned char *personalization_string,
+                      int security_strength);
+
+/**
+ * Random byte generation.
+ * 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
+ */
+int randombytes(unsigned char *x, unsigned long long xlen);
+
+#endif /* rng_h */

include/sig.h

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+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef SQISIGN_H
+#define SQISIGN_H
+
+#include <stdint.h>
+
+/**
+ * SQIsign keypair generation.
+ *
+ * The implementation corresponds to SQIsign.CompactKeyGen() in the SQIsign spec.
+ * The caller is responsible to allocate sufficient memory to hold pk and sk.
+ *
+ * @param[out] pk SQIsign public key
+ * @param[out] sk SQIsign secret key
+ * @return int status code
+ */
+int sqisign_keypair(unsigned char *pk, unsigned char *sk);
+
+/**
+ * SQIsign signature generation.
+ *
+ * The implementation performs SQIsign.expandSK() + SQIsign.sign() in the SQIsign spec.
+ * Keys provided is a compacted secret keys.
+ * The caller is responsible to allocate sufficient memory to hold sm.
+ *
+ * @param[out] sm Signature concatenated with message
+ * @param[out] smlen Pointer to the length of sm
+ * @param[in] m Message to be signed
+ * @param[in] mlen Message length
+ * @param[in] sk Compacted secret key
+ * @return int status code
+ */
+int sqisign_sign(unsigned char *sm,
+              unsigned long long *smlen, const unsigned char *m,
+              unsigned long long mlen, const unsigned char *sk);
+
+/**
+ * SQIsign open signature.
+ *
+ * The implementation performs SQIsign.verify(). If the signature verification succeeded, the original message is stored in m.
+ * Keys provided is a compact public key.
+ * The caller is responsible to allocate sufficient memory to hold m.
+ *
+ * @param[out] m Message stored if verification succeeds
+ * @param[out] mlen Pointer to the length of m
+ * @param[in] sm Signature concatenated with message
+ * @param[in] smlen Length of sm
+ * @param[in] pk Compacted public key
+ * @return int status code
+ */
+int sqisign_open(unsigned char *m,
+              unsigned long long *mlen, const unsigned char *sm,
+              unsigned long long smlen, const unsigned char *pk);
+
+
+/**
+ * SQIsign verify signature.
+ *
+ * If the signature verification succeeded, returns 0, otherwise 1.
+ *
+ * @param[out] m Message stored if verification succeeds
+ * @param[out] mlen Pointer to the length of m
+ * @param[in] sig Signature
+ * @param[in] siglen Length of sig
+ * @param[in] pk Compacted public key
+ * @return int 0 if verification succeeded, 1 otherwise.
+ */
+int sqisign_verify(const unsigned char *m,
+                unsigned long long mlen, const unsigned char *sig,
+                unsigned long long siglen, const unsigned char *pk);
+
+#endif