fix libntrup avx2 detection

CMakeLists.txt

@@ -291,7 +291,7 @@ include_directories(crypto/libntrup/include)
 set(NTRU_SRC
   ${NTRU_AVX_SRC}
   ${NTRU_REF_SRC}
-  crypto/libntrup/src/ntru.c
+  crypto/libntrup/src/ntru.cpp
 )
 
 set(LIB_SRC 

crypto/libntrup/src/avx/dec.c

@@ -11,12 +11,14 @@
 #include "crypto_verify_32.h"
 #include "crypto_kem.h"
 
+
 int crypto_kem_dec_avx2(
   unsigned char *k,
   const unsigned char *cstr,
   const unsigned char *sk
 )
 {
+  #if __AVX2__
   small f[768];
   modq h[768];
   small grecip[768];
@@ -64,4 +66,7 @@ int crypto_kem_dec_avx2(
 
   for (i = 0;i < 32;++i) k[i] = (hash[32 + i] & ~result);
   return result;
+  #else
+  return -1;
+  #endif
 }

crypto/libntrup/src/avx/enc.c

@@ -15,6 +15,7 @@ int crypto_kem_enc_avx2(
   const unsigned char *pk
 )
 {
+#if __AVX2__
   small r[768];
   modq h[768];
   modq c[768];
@@ -45,4 +46,7 @@ int crypto_kem_enc_avx2(
   rq_roundencode(cstr + 32,c);
 
   return 0;
+#else
+  return -1; 
+#endif
 }

crypto/libntrup/src/avx/keypair.c

@@ -15,6 +15,7 @@
 
 int crypto_kem_keypair_avx2(unsigned char *pk,unsigned char *sk)
 {
+#if __AVX2__
   small g[768];
   small grecip[768];
   small f[768];
@@ -36,4 +37,7 @@ int crypto_kem_keypair_avx2(unsigned char *pk,unsigned char *sk)
   memcpy(sk + 2 * small_encode_len,pk,rq_encode_len);
 
   return 0;
+#else
+  return -1;
+#endif
 }

crypto/libntrup/src/ntru.c

@@ -1,68 +0,0 @@
-#include <libntrup/ntru.h>
-#include <stdbool.h>
-
-
-#if __AVX__
-#include <cpuid.h>
-
-static bool supports_avx2()
-{
-  int cpuinfo[4] = {-1};
-  __cpuid(0, cpuinfo[0], cpuinfo[1], cpuinfo[2], cpuinfo[3]);
-  if(cpuinfo[0] < 7)
-    return false;
-    __cpuid(7, cpuinfo[0], cpuinfo[1], cpuinfo[2], cpuinfo[3]);
-  return cpuinfo[1] & (1 << 5);
-}
-
-
-#else
-
-static bool supports_avx2()
-{
-  return false;
-}
-
-#endif
-
-
-int (*__crypto_kem_enc)(unsigned char *cstr, unsigned char *k, const unsigned char *pk);
-  
-int (*__crypto_kem_dec)(unsigned char *k, const unsigned char *cstr, const unsigned char *sk);
-
-int (*__crypto_kem_keypair)(unsigned char *pk, unsigned char * sk);
-
-void ntru_init()
-{
-  if(supports_avx2())
-  {
-    __crypto_kem_dec = &crypto_kem_dec_avx2;
-    __crypto_kem_enc = &crypto_kem_enc_avx2;
-    __crypto_kem_dec = &crypto_kem_dec_avx2;
-    __crypto_kem_keypair = &crypto_kem_keypair_avx2;
-  }
-  else
-  {
-    __crypto_kem_dec = &crypto_kem_dec_ref;
-    __crypto_kem_enc = &crypto_kem_enc_ref;
-    __crypto_kem_dec = &crypto_kem_dec_ref;
-    __crypto_kem_keypair = &crypto_kem_keypair_ref;
-  }
-  
-}
-
-
-int crypto_kem_enc(unsigned char *cstr, unsigned char *k, const unsigned char *pk)
-{
-  return __crypto_kem_enc(cstr, k, pk);
-}
-  
-int crypto_kem_dec(unsigned char *k, const unsigned char *cstr, const unsigned char *sk) 
-{
-  return __crypto_kem_dec(k, cstr, sk);
-}
-
-int crypto_kem_keypair(unsigned char *pk, unsigned char * sk) 
-{
- return __crypto_kem_keypair(pk, sk);
-}

crypto/libntrup/src/ntru.cpp

@@ -0,0 +1,80 @@
+#include <libntrup/ntru.h>
+#include <stdbool.h>
+
+#if __AVX2__
+#include <cpuid.h>
+#include <array>
+
+std::array< int, 4 >
+CPUID(int funcno)
+{
+  std::array< int, 4 > cpuinfo;
+  __cpuid(funcno, cpuinfo[0], cpuinfo[1], cpuinfo[2], cpuinfo[3]);
+  return cpuinfo;
+}
+
+bool
+supports_avx2()
+{
+  return CPUID(0).at(0) >= 7 && CPUID(7).at(1) & (1 << 5);
+}
+
+#else
+
+bool
+supports_avx2()
+{
+  printf("AVX2 disabled on compile time\n");
+  return false;
+}
+
+#endif
+
+int (*__crypto_kem_enc)(unsigned char *cstr, unsigned char *k,
+                        const unsigned char *pk);
+
+int (*__crypto_kem_dec)(unsigned char *k, const unsigned char *cstr,
+                        const unsigned char *sk);
+
+int (*__crypto_kem_keypair)(unsigned char *pk, unsigned char *sk);
+
+extern "C"
+{
+  void
+  ntru_init()
+  {
+    if(supports_avx2())
+    {
+      __crypto_kem_dec     = &crypto_kem_dec_avx2;
+      __crypto_kem_enc     = &crypto_kem_enc_avx2;
+      __crypto_kem_dec     = &crypto_kem_dec_avx2;
+      __crypto_kem_keypair = &crypto_kem_keypair_avx2;
+    }
+    else
+    {
+      __crypto_kem_dec     = &crypto_kem_dec_ref;
+      __crypto_kem_enc     = &crypto_kem_enc_ref;
+      __crypto_kem_dec     = &crypto_kem_dec_ref;
+      __crypto_kem_keypair = &crypto_kem_keypair_ref;
+    }
+  }
+
+  int
+  crypto_kem_enc(unsigned char *cstr, unsigned char *k, const unsigned char *pk)
+  {
+    return __crypto_kem_enc(cstr, k, pk);
+  }
+
+  int
+  crypto_kem_dec(unsigned char *k, const unsigned char *cstr,
+                 const unsigned char *sk)
+  {
+    return __crypto_kem_dec(k, cstr, sk);
+  }
+
+  int
+  crypto_kem_keypair(unsigned char *pk, unsigned char *sk)
+  {
+    return __crypto_kem_keypair(pk, sk);
+  }
+}