imported fix from CROSS upstream: endianness-aware csprng

docs/algorithms/sig/cross.md

@@ -5,9 +5,9 @@
 - **Principal submitters**: Marco Baldi, Alessandro Barenghi, Sebastian Bitzer, Patrick Karl, Felice Manganiello, Alessio Pavoni, Gerardo Pelosi, Paolo Santini, Jonas Schupp, Freeman Slaughter, Antonia Wachter-Zeh, Violetta Weger.
 - **Auxiliary submitters**: Marco Gianvecchio.
 - **Authors' website**: https://www.cross-crypto.com/
-- **Specification version**: 1.2 + Keccak_x4 + PQClean fixes.
+- **Specification version**: 1.2 + Keccak_x4 + PQClean fixes + endianness fix.
 - **Primary Source**<a name="primary-source"></a>:
-  - **Source**: https://github.com/rtjk/CROSS-PQClean/commit/577d7c761c684637923c8648644cf2f4d7b41954
+  - **Source**: https://github.com/rtjk/CROSS-PQClean/commit/82938638cb6bcb680d9472e544a61be38db806cc
   - **Implementation license (SPDX-Identifier)**: CC0-1.0
 
 

docs/algorithms/sig/cross.yml

@@ -19,9 +19,9 @@ crypto-assumption: hardness of the restricted syndrome decoding problem for rand
   linear codes on a finite field
 website: https://www.cross-crypto.com/
 nist-round: 1
-spec-version: 1.2 + Keccak_x4 + PQClean fixes
+spec-version: 1.2 + Keccak_x4 + PQClean fixes + endianness fix
 primary-upstream:
-  source: https://github.com/rtjk/CROSS-PQClean/commit/577d7c761c684637923c8648644cf2f4d7b41954
+  source: https://github.com/rtjk/CROSS-PQClean/commit/82938638cb6bcb680d9472e544a61be38db806cc
   spdx-license-identifier: CC0-1.0
 parameter-sets:
 - name: cross-rsdp-128-balanced

scripts/copy_from_upstream/copy_from_upstream.yml

@@ -66,7 +66,7 @@ upstreams:
     name: upcross
     git_url: https://github.com/rtjk/CROSS-PQClean.git
     git_branch: master
-    git_commit: 577d7c761c684637923c8648644cf2f4d7b41954
+    git_commit: 82938638cb6bcb680d9472e544a61be38db806cc
     sig_meta_path: 'generate/crypto_sign/{pqclean_scheme}/META.yml'
     sig_scheme_path: 'generate/crypto_sign/{pqclean_scheme}'
 kems:

src/sig/cross/upcross_cross-rsdp-128-balanced_avx2/csprng_hash.h

@@ -214,6 +214,37 @@ FQ_ELEM fq_star_rnd_state(CSPRNG_STATE_T *const csprng_state) {
 	return rnd_value + 1;
 } /* end fq_star_rnd_state */
 
+/********************* Endianness detection and handling **********************/
+
+#define BIG_ENDIAN_SYSTEM 0 // assume little-endian by default
+
+/* Check if we are on a big-endian system:
+ * the __BYTE_ORDER__ macro is defined by the compiler
+ * recent versions of GCC and Clang define it
+ * other methods to detect endianness might be needed when using different compilers */
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#undef BIG_ENDIAN_SYSTEM
+#define BIG_ENDIAN_SYSTEM 1
+#endif
+
+static inline uint64_t to_little_endian64(uint64_t x) {
+	/* When compiling on a big-endian system, swap the bytes */
+#if BIG_ENDIAN_SYSTEM
+	return __builtin_bswap64(x);
+#else
+	return x;
+#endif
+}
+
+static inline uint32_t to_little_endian32(uint32_t x) {
+	/* When compiling on a big-endian system, swap the bytes */
+#if BIG_ENDIAN_SYSTEM
+	return __builtin_bswap32(x);
+#else
+	return x;
+#endif
+}
+
 /***************** Specialized CSPRNGs for non binary domains *****************/
 
 /* CSPRNG sampling fixed weight strings */
@@ -249,14 +280,14 @@ void CSPRNG_fq_vec(FQ_ELEM res[N],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_VEC, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < N) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -298,14 +329,14 @@ void CSPRNG_fq_vec_beta(FQ_ELEM res[T],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_VEC_BETA, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < T) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -345,15 +376,15 @@ void CSPRNG_fq_mat(FQ_ELEM res[K][N - K],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_MAT, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 
 	while (placed < K * (N - K)) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -393,14 +424,14 @@ void CSPRNG_zz_vec(FZ_ELEM res[N],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_ZZ_VEC, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < N) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;

src/sig/cross/upcross_cross-rsdp-128-balanced_clean/csprng_hash.h

@@ -214,6 +214,37 @@ FQ_ELEM fq_star_rnd_state(CSPRNG_STATE_T *const csprng_state) {
 	return rnd_value + 1;
 } /* end fq_star_rnd_state */
 
+/********************* Endianness detection and handling **********************/
+
+#define BIG_ENDIAN_SYSTEM 0 // assume little-endian by default
+
+/* Check if we are on a big-endian system:
+ * the __BYTE_ORDER__ macro is defined by the compiler
+ * recent versions of GCC and Clang define it
+ * other methods to detect endianness might be needed when using different compilers */
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#undef BIG_ENDIAN_SYSTEM
+#define BIG_ENDIAN_SYSTEM 1
+#endif
+
+static inline uint64_t to_little_endian64(uint64_t x) {
+	/* When compiling on a big-endian system, swap the bytes */
+#if BIG_ENDIAN_SYSTEM
+	return __builtin_bswap64(x);
+#else
+	return x;
+#endif
+}
+
+static inline uint32_t to_little_endian32(uint32_t x) {
+	/* When compiling on a big-endian system, swap the bytes */
+#if BIG_ENDIAN_SYSTEM
+	return __builtin_bswap32(x);
+#else
+	return x;
+#endif
+}
+
 /***************** Specialized CSPRNGs for non binary domains *****************/
 
 /* CSPRNG sampling fixed weight strings */
@@ -249,14 +280,14 @@ void CSPRNG_fq_vec(FQ_ELEM res[N],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_VEC, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < N) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -298,14 +329,14 @@ void CSPRNG_fq_vec_beta(FQ_ELEM res[T],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_VEC_BETA, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < T) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -345,15 +376,15 @@ void CSPRNG_fq_mat(FQ_ELEM res[K][N - K],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_MAT, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 
 	while (placed < K * (N - K)) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -393,14 +424,14 @@ void CSPRNG_zz_vec(FZ_ELEM res[N],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_ZZ_VEC, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < N) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;

src/sig/cross/upcross_cross-rsdp-128-fast_avx2/csprng_hash.h

@@ -214,6 +214,37 @@ FQ_ELEM fq_star_rnd_state(CSPRNG_STATE_T *const csprng_state) {
 	return rnd_value + 1;
 } /* end fq_star_rnd_state */
 
+/********************* Endianness detection and handling **********************/
+
+#define BIG_ENDIAN_SYSTEM 0 // assume little-endian by default
+
+/* Check if we are on a big-endian system:
+ * the __BYTE_ORDER__ macro is defined by the compiler
+ * recent versions of GCC and Clang define it
+ * other methods to detect endianness might be needed when using different compilers */
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#undef BIG_ENDIAN_SYSTEM
+#define BIG_ENDIAN_SYSTEM 1
+#endif
+
+static inline uint64_t to_little_endian64(uint64_t x) {
+	/* When compiling on a big-endian system, swap the bytes */
+#if BIG_ENDIAN_SYSTEM
+	return __builtin_bswap64(x);
+#else
+	return x;
+#endif
+}
+
+static inline uint32_t to_little_endian32(uint32_t x) {
+	/* When compiling on a big-endian system, swap the bytes */
+#if BIG_ENDIAN_SYSTEM
+	return __builtin_bswap32(x);
+#else
+	return x;
+#endif
+}
+
 /***************** Specialized CSPRNGs for non binary domains *****************/
 
 /* CSPRNG sampling fixed weight strings */
@@ -249,14 +280,14 @@ void CSPRNG_fq_vec(FQ_ELEM res[N],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_VEC, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < N) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -298,14 +329,14 @@ void CSPRNG_fq_vec_beta(FQ_ELEM res[T],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_VEC_BETA, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < T) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -345,15 +376,15 @@ void CSPRNG_fq_mat(FQ_ELEM res[K][N - K],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_FQ_MAT, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 
 	while (placed < K * (N - K)) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;
@@ -393,14 +424,14 @@ void CSPRNG_zz_vec(FZ_ELEM res[N],
 	 * in from the left end */
 	csprng_randombytes(CSPRNG_buffer, BUFSIZE_ZZ_VEC, csprng_state);
 	int placed = 0;
-	uint64_t sub_buffer = *(uint64_t *)CSPRNG_buffer;
+	uint64_t sub_buffer = to_little_endian64(*(uint64_t *)CSPRNG_buffer);
 	int bits_in_sub_buf = 64;
 	/* position of the next fresh byte in CSPRNG_buffer*/
 	int pos_in_buf = 8;
 	while (placed < N) {
 		if (bits_in_sub_buf <= 32) {
 			/* get 32 fresh bits from main buffer with a single load */
-			uint32_t refresh_buf = *(uint32_t *) (CSPRNG_buffer + pos_in_buf);
+			uint32_t refresh_buf = to_little_endian32(*(uint32_t *) (CSPRNG_buffer + pos_in_buf));
 			pos_in_buf += 4;
 			sub_buffer |=  ((uint64_t) refresh_buf) << bits_in_sub_buf;
 			bits_in_sub_buf += 32;