Merge pull request #325 from jschanck/test_boolean

Ban boolean operators in arithmetic expressions

crypto_kem/frodokem1344aes/clean/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM1344AES_CLEAN_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem1344aes/opt/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM1344AES_OPT_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem1344shake/clean/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM1344SHAKE_CLEAN_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem1344shake/opt/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM1344SHAKE_OPT_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem640aes/clean/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM640AES_CLEAN_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem640aes/opt/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM640AES_OPT_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem640shake/clean/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM640SHAKE_CLEAN_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem640shake/opt/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM640SHAKE_OPT_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem976aes/clean/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM976AES_CLEAN_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem976aes/opt/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM976AES_OPT_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem976shake/clean/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM976SHAKE_CLEAN_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/frodokem976shake/opt/util.c

@@ -11,7 +11,12 @@
 #include "common.h"
 #include "params.h"
 
-#define min(x, y) (((x) < (y)) ? (x) : (y))
+static inline uint8_t min(uint8_t x, uint8_t y) {
+    if (x < y) {
+        return x;
+    }
+    return y;
+}
 
 uint16_t PQCLEAN_FRODOKEM976SHAKE_OPT_LE_TO_UINT16(uint16_t n) {
     return (((uint8_t *) &n)[0] | (((uint8_t *) &n)[1] << 8));

crypto_kem/mceliece348864/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece348864f/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece460896/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece460896f/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece6688128/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece6688128f/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece6960119/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece6960119f/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece8192128/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/mceliece8192128f/avx/int32_sort.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/ntruhps2048509/avx2/crypto_sort_int32.c

@@ -1,8 +1,8 @@
+#include "crypto_sort_int32.h"
+#include <immintrin.h>
 // Based on supercop-20200820/crypto_sort/int32/avx2
 
-#include "crypto_sort_int32.h"
 
-#include <immintrin.h>
 #define int32 int32_t
 
 typedef __m256i int32x8;
@@ -469,8 +469,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/ntruhps2048509/avx2/crypto_sort_int32.h

@@ -1,11 +1,10 @@
 #ifndef CRYPTO_SORT
 #define CRYPTO_SORT
-
 #include "params.h"
-
 #include <stddef.h>
 #include <stdint.h>
 
+
 void PQCLEAN_NTRUHPS2048509_AVX2_crypto_sort_int32(int32_t *x, size_t n);
 
 #endif

crypto_kem/ntruhps2048677/avx2/crypto_sort_int32.c

@@ -1,8 +1,8 @@
+#include "crypto_sort_int32.h"
+#include <immintrin.h>
 // Based on supercop-20200820/crypto_sort/int32/avx2
 
-#include "crypto_sort_int32.h"
 
-#include <immintrin.h>
 #define int32 int32_t
 
 typedef __m256i int32x8;
@@ -469,8 +469,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/ntruhps2048677/avx2/crypto_sort_int32.h

@@ -1,11 +1,10 @@
 #ifndef CRYPTO_SORT
 #define CRYPTO_SORT
-
 #include "params.h"
-
 #include <stddef.h>
 #include <stdint.h>
 
+
 void PQCLEAN_NTRUHPS2048677_AVX2_crypto_sort_int32(int32_t *x, size_t n);
 
 #endif

crypto_kem/ntruhps4096821/avx2/crypto_sort_int32.c

@@ -1,8 +1,8 @@
+#include "crypto_sort_int32.h"
+#include <immintrin.h>
 // Based on supercop-20200820/crypto_sort/int32/avx2
 
-#include "crypto_sort_int32.h"
 
-#include <immintrin.h>
 #define int32 int32_t
 
 typedef __m256i int32x8;
@@ -469,8 +469,11 @@ static void int32_sort_2power(int32 *x, size_t n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/ntruhps4096821/avx2/crypto_sort_int32.h

@@ -1,11 +1,10 @@
 #ifndef CRYPTO_SORT
 #define CRYPTO_SORT
-
 #include "params.h"
-
 #include <stddef.h>
 #include <stdint.h>
 
+
 void PQCLEAN_NTRUHPS4096821_AVX2_crypto_sort_int32(int32_t *x, size_t n);
 
 #endif

crypto_kem/ntrulpr653/avx2/crypto_sort_int32.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, long long n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/ntrulpr761/avx2/crypto_sort_int32.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, long long n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/ntrulpr857/avx2/crypto_sort_int32.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, long long n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/sntrup653/avx2/crypto_sort_int32.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, long long n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/sntrup761/avx2/crypto_sort_int32.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, long long n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_kem/sntrup857/avx2/crypto_sort_int32.c

@@ -462,8 +462,11 @@ static void int32_sort_2power(int32 *x, long long n, int flagdown) {
             }
 
             q = n >> 3;
-            flip = (p << 1 == q);
-            flipflip = !flip;
+            flip = 0;
+            if (p << 1 == q) {
+                flip = 1;
+            }
+            flipflip = 1 - flip;
             for (j = 0; j < q; j += p + p) {
                 for (k = j; k < j + p + p; k += p) {
                     for (i = k; i < k + p; i += 8) {

crypto_sign/falcon-1024/clean/codec.c

@@ -443,7 +443,10 @@ PQCLEAN_FALCON1024_CLEAN_comp_decode(
                 return 0;
             }
         }
-        x[u] = (int16_t)(s ? -(int)m : (int)m);
+        x[u] = (int16_t) m;
+        if (s) {
+            x[u] = (int16_t) - x[u];
+        }
     }
     return v;
 }

crypto_sign/falcon-1024/clean/fpr.h

@@ -424,20 +424,32 @@ fpr fpr_sqrt(fpr x);
 static inline int
 fpr_lt(fpr x, fpr y) {
     /*
-     * If x >= 0 or y >= 0, a signed comparison yields the proper
-     * result:
+     * If both x and y are positive, then a signed comparison yields
+     * the proper result:
      *   - For positive values, the order is preserved.
      *   - The sign bit is at the same place as in integers, so
      *     sign is preserved.
+     * Moreover, we can compute [x < y] as sgn(x-y) and the computation
+     * of x-y will not overflow.
+     *
+     * If the signs differ, then sgn(x) gives the proper result.
      *
      * If both x and y are negative, then the order is reversed.
-     * We cannot simply invert the comparison result in that case
-     * because it would not handle the edge case x = y properly.
+     * Hence [x < y] = sgn(y-x). We must compute this separately from
+     * sgn(x-y); simply inverting sgn(x-y) would not handle the edge
+     * case x = y properly.
      */
     int cc0, cc1;
+    int64_t sx;
+    int64_t sy;
+
+    sx = *(int64_t *)&x;
+    sy = *(int64_t *)&y;
+    sy &= ~((sx ^ sy) >> 63); /* set sy=0 if signs differ */
+
+    cc0 = (int)((sx - sy) >> 63) & 1; /* Neither subtraction overflows when */
+    cc1 = (int)((sy - sx) >> 63) & 1; /* the signs are the same. */
 
-    cc0 = *(int64_t *)&x < *(int64_t *)&y;
-    cc1 = *(int64_t *)&x > *(int64_t *)&y;
     return cc0 ^ ((cc0 ^ cc1) & (int)((x & y) >> 63));
 }
 

crypto_sign/falcon-1024/clean/keygen.c

@@ -1902,7 +1902,11 @@ zint_add_scaled_mul_small(uint32_t *x, size_t xlen,
          * Get the next word of y (scaled).
          */
         v = u - sch;
-        wy = v < ylen ? y[v] : ysign;
+        if (v < ylen) {
+            wy = y[v];
+        } else {
+            wy = ysign;
+        }
         wys = ((wy << scl) & 0x7FFFFFFF) | tw;
         tw = wy >> (31 - scl);
 
@@ -1960,7 +1964,11 @@ zint_sub_scaled(uint32_t *x, size_t xlen,
          * Get the next word of y (scaled).
          */
         v = u - sch;
-        wy = v < ylen ? y[v] : ysign;
+        if (v < ylen) {
+            wy = y[v];
+        } else {
+            wy = ysign;
+        }
         wys = ((wy << scl) & 0x7FFFFFFF) | tw;
         tw = wy >> (31 - scl);
 
@@ -2648,10 +2656,18 @@ make_fg(uint32_t *data, const int8_t *f, const int8_t *g,
         return;
     }
 
-    for (d = 0; d < depth; d ++) {
-        make_fg_step(data, logn - d, d,
-                     d != 0, (d + 1) < depth || out_ntt);
+    if (depth == 0) {
+        return;
     }
+    if (depth == 1) {
+        make_fg_step(data, logn, 0, 0, out_ntt);
+        return;
+    }
+    make_fg_step(data, logn, 0, 0, 1);
+    for (d = 1; d + 1 < depth; d ++) {
+        make_fg_step(data, logn - d, d, 1, 1);
+    }
+    make_fg_step(data, logn - depth + 1, depth - 1, 1, out_ntt);
 }
 
 /*
@@ -3028,7 +3044,10 @@ solve_NTRU_intermediate(unsigned logn_top,
      * computed so that average maximum length will fall in the
      * middle or the upper half of these top 10 words.
      */
-    rlen = (slen > 10) ? 10 : slen;
+    rlen = slen;
+    if (rlen > 10) {
+        rlen = 10;
+    }
     poly_big_to_fp(rt3, ft + slen - rlen, rlen, slen, logn);
     poly_big_to_fp(rt4, gt + slen - rlen, rlen, slen, logn);
 
@@ -3102,7 +3121,10 @@ solve_NTRU_intermediate(unsigned logn_top,
          * Convert current F and G into floating-point. We apply
          * scaling if the current length is more than 10 words.
          */
-        rlen = (FGlen > 10) ? 10 : FGlen;
+        rlen = FGlen;
+        if (rlen > 10) {
+            rlen = 10;
+        }
         scale_FG = 31 * (int)(FGlen - rlen);
         poly_big_to_fp(rt1, Ft + FGlen - rlen, rlen, llen, logn);
         poly_big_to_fp(rt2, Gt + FGlen - rlen, rlen, llen, logn);

crypto_sign/falcon-1024/clean/sign.c

@@ -1189,9 +1189,11 @@ PQCLEAN_FALCON1024_CLEAN_sign_tree(int16_t *sig, inner_shake256_context *rng,
          * Normal sampling. We use a fast PRNG seeded from our
          * SHAKE context ('rng').
          */
-        spc.sigma_min = (logn == 10)
-                        ? fpr_sigma_min_10
-                        : fpr_sigma_min_9;
+        if (logn == 10) {
+            spc.sigma_min = fpr_sigma_min_10;
+        } else {
+            spc.sigma_min = fpr_sigma_min_9;
+        }
         PQCLEAN_FALCON1024_CLEAN_prng_init(&spc.p, rng);
         samp = PQCLEAN_FALCON1024_CLEAN_sampler;
         samp_ctx = &spc;
@@ -1234,9 +1236,11 @@ PQCLEAN_FALCON1024_CLEAN_sign_dyn(int16_t *sig, inner_shake256_context *rng,
          * Normal sampling. We use a fast PRNG seeded from our
          * SHAKE context ('rng').
          */
-        spc.sigma_min = (logn == 10)
-                        ? fpr_sigma_min_10
-                        : fpr_sigma_min_9;
+        if (logn == 10) {
+            spc.sigma_min = fpr_sigma_min_10;
+        } else {
+            spc.sigma_min = fpr_sigma_min_9;
+        }
         PQCLEAN_FALCON1024_CLEAN_prng_init(&spc.p, rng);
         samp = PQCLEAN_FALCON1024_CLEAN_sampler;
         samp_ctx = &spc;

crypto_sign/falcon-512/clean/codec.c

@@ -443,7 +443,10 @@ PQCLEAN_FALCON512_CLEAN_comp_decode(
                 return 0;
             }
         }
-        x[u] = (int16_t)(s ? -(int)m : (int)m);
+        x[u] = (int16_t) m;
+        if (s) {
+            x[u] = (int16_t) - x[u];
+        }
     }
     return v;
 }

crypto_sign/falcon-512/clean/fpr.h

@@ -424,20 +424,32 @@ fpr fpr_sqrt(fpr x);
 static inline int
 fpr_lt(fpr x, fpr y) {
     /*
-     * If x >= 0 or y >= 0, a signed comparison yields the proper
-     * result:
+     * If both x and y are positive, then a signed comparison yields
+     * the proper result:
      *   - For positive values, the order is preserved.
      *   - The sign bit is at the same place as in integers, so
      *     sign is preserved.
+     * Moreover, we can compute [x < y] as sgn(x-y) and the computation
+     * of x-y will not overflow.
+     *
+     * If the signs differ, then sgn(x) gives the proper result.
      *
      * If both x and y are negative, then the order is reversed.
-     * We cannot simply invert the comparison result in that case
-     * because it would not handle the edge case x = y properly.
+     * Hence [x < y] = sgn(y-x). We must compute this separately from
+     * sgn(x-y); simply inverting sgn(x-y) would not handle the edge
+     * case x = y properly.
      */
     int cc0, cc1;
+    int64_t sx;
+    int64_t sy;
+
+    sx = *(int64_t *)&x;
+    sy = *(int64_t *)&y;
+    sy &= ~((sx ^ sy) >> 63); /* set sy=0 if signs differ */
+
+    cc0 = (int)((sx - sy) >> 63) & 1; /* Neither subtraction overflows when */
+    cc1 = (int)((sy - sx) >> 63) & 1; /* the signs are the same. */
 
-    cc0 = *(int64_t *)&x < *(int64_t *)&y;
-    cc1 = *(int64_t *)&x > *(int64_t *)&y;
     return cc0 ^ ((cc0 ^ cc1) & (int)((x & y) >> 63));
 }
 

crypto_sign/falcon-512/clean/keygen.c

@@ -1902,7 +1902,11 @@ zint_add_scaled_mul_small(uint32_t *x, size_t xlen,
          * Get the next word of y (scaled).
          */
         v = u - sch;
-        wy = v < ylen ? y[v] : ysign;
+        if (v < ylen) {
+            wy = y[v];
+        } else {
+            wy = ysign;
+        }
         wys = ((wy << scl) & 0x7FFFFFFF) | tw;
         tw = wy >> (31 - scl);
 
@@ -1960,7 +1964,11 @@ zint_sub_scaled(uint32_t *x, size_t xlen,
          * Get the next word of y (scaled).
          */
         v = u - sch;
-        wy = v < ylen ? y[v] : ysign;
+        if (v < ylen) {
+            wy = y[v];
+        } else {
+            wy = ysign;
+        }
         wys = ((wy << scl) & 0x7FFFFFFF) | tw;
         tw = wy >> (31 - scl);
 
@@ -2648,10 +2656,18 @@ make_fg(uint32_t *data, const int8_t *f, const int8_t *g,
         return;
     }
 
-    for (d = 0; d < depth; d ++) {
-        make_fg_step(data, logn - d, d,
-                     d != 0, (d + 1) < depth || out_ntt);
+    if (depth == 0) {
+        return;
     }
+    if (depth == 1) {
+        make_fg_step(data, logn, 0, 0, out_ntt);
+        return;
+    }
+    make_fg_step(data, logn, 0, 0, 1);
+    for (d = 1; d + 1 < depth; d ++) {
+        make_fg_step(data, logn - d, d, 1, 1);
+    }
+    make_fg_step(data, logn - depth + 1, depth - 1, 1, out_ntt);
 }
 
 /*
@@ -3028,7 +3044,10 @@ solve_NTRU_intermediate(unsigned logn_top,
      * computed so that average maximum length will fall in the
      * middle or the upper half of these top 10 words.
      */
-    rlen = (slen > 10) ? 10 : slen;
+    rlen = slen;
+    if (rlen > 10) {
+        rlen = 10;
+    }
     poly_big_to_fp(rt3, ft + slen - rlen, rlen, slen, logn);
     poly_big_to_fp(rt4, gt + slen - rlen, rlen, slen, logn);
 
@@ -3102,7 +3121,10 @@ solve_NTRU_intermediate(unsigned logn_top,
          * Convert current F and G into floating-point. We apply
          * scaling if the current length is more than 10 words.
          */
-        rlen = (FGlen > 10) ? 10 : FGlen;
+        rlen = FGlen;
+        if (rlen > 10) {
+            rlen = 10;
+        }
         scale_FG = 31 * (int)(FGlen - rlen);
         poly_big_to_fp(rt1, Ft + FGlen - rlen, rlen, llen, logn);
         poly_big_to_fp(rt2, Gt + FGlen - rlen, rlen, llen, logn);

crypto_sign/falcon-512/clean/sign.c

@@ -1189,9 +1189,11 @@ PQCLEAN_FALCON512_CLEAN_sign_tree(int16_t *sig, inner_shake256_context *rng,
          * Normal sampling. We use a fast PRNG seeded from our
          * SHAKE context ('rng').
          */
-        spc.sigma_min = (logn == 10)
-                        ? fpr_sigma_min_10
-                        : fpr_sigma_min_9;
+        if (logn == 10) {
+            spc.sigma_min = fpr_sigma_min_10;
+        } else {
+            spc.sigma_min = fpr_sigma_min_9;
+        }
         PQCLEAN_FALCON512_CLEAN_prng_init(&spc.p, rng);
         samp = PQCLEAN_FALCON512_CLEAN_sampler;
         samp_ctx = &spc;
@@ -1234,9 +1236,11 @@ PQCLEAN_FALCON512_CLEAN_sign_dyn(int16_t *sig, inner_shake256_context *rng,
          * Normal sampling. We use a fast PRNG seeded from our
          * SHAKE context ('rng').
          */
-        spc.sigma_min = (logn == 10)
-                        ? fpr_sigma_min_10
-                        : fpr_sigma_min_9;
+        if (logn == 10) {
+            spc.sigma_min = fpr_sigma_min_10;
+        } else {
+            spc.sigma_min = fpr_sigma_min_9;
+        }
         PQCLEAN_FALCON512_CLEAN_prng_init(&spc.p, rng);
         samp = PQCLEAN_FALCON512_CLEAN_sampler;
         samp_ctx = &spc;

crypto_sign/rainbowIIIc-classic/clean/blas_comm.c

@@ -72,7 +72,7 @@ static unsigned int gf256mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsign
 
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + w * j;
-            PQCLEAN_RAINBOWIIICCLASSIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, !PQCLEAN_RAINBOWIIICCLASSIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
+            PQCLEAN_RAINBOWIIICCLASSIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, 1 ^ PQCLEAN_RAINBOWIIICCLASSIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
         }
         r8 &= PQCLEAN_RAINBOWIIICCLASSIC_CLEAN_gf256_is_nonzero(ai[i]);
         uint8_t pivot = ai[i];

crypto_sign/rainbowIIIc-cyclic-compressed/clean/blas_comm.c

@@ -72,7 +72,7 @@ static unsigned int gf256mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsign
 
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + w * j;
-            PQCLEAN_RAINBOWIIICCYCLICCOMPRESSED_CLEAN_gf256v_predicated_add(ai + skip_len_align4, !PQCLEAN_RAINBOWIIICCYCLICCOMPRESSED_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
+            PQCLEAN_RAINBOWIIICCYCLICCOMPRESSED_CLEAN_gf256v_predicated_add(ai + skip_len_align4, 1 ^ PQCLEAN_RAINBOWIIICCYCLICCOMPRESSED_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
         }
         r8 &= PQCLEAN_RAINBOWIIICCYCLICCOMPRESSED_CLEAN_gf256_is_nonzero(ai[i]);
         uint8_t pivot = ai[i];

crypto_sign/rainbowIIIc-cyclic/clean/blas_comm.c

@@ -72,7 +72,7 @@ static unsigned int gf256mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsign
 
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + w * j;
-            PQCLEAN_RAINBOWIIICCYCLIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, !PQCLEAN_RAINBOWIIICCYCLIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
+            PQCLEAN_RAINBOWIIICCYCLIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, 1 ^ PQCLEAN_RAINBOWIIICCYCLIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
         }
         r8 &= PQCLEAN_RAINBOWIIICCYCLIC_CLEAN_gf256_is_nonzero(ai[i]);
         uint8_t pivot = ai[i];

crypto_sign/rainbowIa-classic/clean/blas_comm.c

@@ -74,7 +74,7 @@ static unsigned int gf16mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsigne
         uint8_t *ai = mat + n_w_byte * i;
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + n_w_byte * j;
-            PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf256v_predicated_add(ai + offset_byte, !PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf16_is_nonzero(PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf16v_get_ele(ai, i)), aj + offset_byte, n_w_byte - offset_byte);
+            PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf256v_predicated_add(ai + offset_byte, 1 ^ PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf16_is_nonzero(PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf16v_get_ele(ai, i)), aj + offset_byte, n_w_byte - offset_byte);
         }
         uint8_t pivot = PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf16v_get_ele(ai, i);
         r8 &= PQCLEAN_RAINBOWIACLASSIC_CLEAN_gf16_is_nonzero(pivot);

crypto_sign/rainbowIa-cyclic-compressed/clean/blas_comm.c

@@ -74,7 +74,7 @@ static unsigned int gf16mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsigne
         uint8_t *ai = mat + n_w_byte * i;
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + n_w_byte * j;
-            PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf256v_predicated_add(ai + offset_byte, !PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf16_is_nonzero(PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf16v_get_ele(ai, i)), aj + offset_byte, n_w_byte - offset_byte);
+            PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf256v_predicated_add(ai + offset_byte, 1 ^ PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf16_is_nonzero(PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf16v_get_ele(ai, i)), aj + offset_byte, n_w_byte - offset_byte);
         }
         uint8_t pivot = PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf16v_get_ele(ai, i);
         r8 &= PQCLEAN_RAINBOWIACYCLICCOMPRESSED_CLEAN_gf16_is_nonzero(pivot);

crypto_sign/rainbowIa-cyclic/clean/blas_comm.c

@@ -74,7 +74,7 @@ static unsigned int gf16mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsigne
         uint8_t *ai = mat + n_w_byte * i;
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + n_w_byte * j;
-            PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf256v_predicated_add(ai + offset_byte, !PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf16_is_nonzero(PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf16v_get_ele(ai, i)), aj + offset_byte, n_w_byte - offset_byte);
+            PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf256v_predicated_add(ai + offset_byte, 1 ^ PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf16_is_nonzero(PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf16v_get_ele(ai, i)), aj + offset_byte, n_w_byte - offset_byte);
         }
         uint8_t pivot = PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf16v_get_ele(ai, i);
         r8 &= PQCLEAN_RAINBOWIACYCLIC_CLEAN_gf16_is_nonzero(pivot);

crypto_sign/rainbowVc-classic/clean/blas_comm.c

@@ -72,7 +72,7 @@ static unsigned int gf256mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsign
 
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + w * j;
-            PQCLEAN_RAINBOWVCCLASSIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, !PQCLEAN_RAINBOWVCCLASSIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
+            PQCLEAN_RAINBOWVCCLASSIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, 1 ^ PQCLEAN_RAINBOWVCCLASSIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
         }
         r8 &= PQCLEAN_RAINBOWVCCLASSIC_CLEAN_gf256_is_nonzero(ai[i]);
         uint8_t pivot = ai[i];

crypto_sign/rainbowVc-cyclic-compressed/clean/blas_comm.c

@@ -72,7 +72,7 @@ static unsigned int gf256mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsign
 
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + w * j;
-            PQCLEAN_RAINBOWVCCYCLICCOMPRESSED_CLEAN_gf256v_predicated_add(ai + skip_len_align4, !PQCLEAN_RAINBOWVCCYCLICCOMPRESSED_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
+            PQCLEAN_RAINBOWVCCYCLICCOMPRESSED_CLEAN_gf256v_predicated_add(ai + skip_len_align4, 1 ^ PQCLEAN_RAINBOWVCCYCLICCOMPRESSED_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
         }
         r8 &= PQCLEAN_RAINBOWVCCYCLICCOMPRESSED_CLEAN_gf256_is_nonzero(ai[i]);
         uint8_t pivot = ai[i];

crypto_sign/rainbowVc-cyclic/clean/blas_comm.c

@@ -72,7 +72,7 @@ static unsigned int gf256mat_gauss_elim_ref(uint8_t *mat, unsigned int h, unsign
 
         for (unsigned int j = i + 1; j < h; j++) {
             uint8_t *aj = mat + w * j;
-            PQCLEAN_RAINBOWVCCYCLIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, !PQCLEAN_RAINBOWVCCYCLIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
+            PQCLEAN_RAINBOWVCCYCLIC_CLEAN_gf256v_predicated_add(ai + skip_len_align4, 1 ^ PQCLEAN_RAINBOWVCCYCLIC_CLEAN_gf256_is_nonzero(ai[i]), aj + skip_len_align4, w - skip_len_align4);
         }
         r8 &= PQCLEAN_RAINBOWVCCYCLIC_CLEAN_gf256_is_nonzero(ai[i]);
         uint8_t pivot = ai[i];

crypto_sign/sphincs-sha256-128f-robust/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256128FROBUST_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-128f-simple/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256128FSIMPLE_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-128s-robust/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256128SROBUST_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-128s-simple/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256128SSIMPLE_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-192f-robust/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256192FROBUST_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-192f-simple/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256192FSIMPLE_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-192s-robust/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256192SROBUST_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-192s-simple/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256192SSIMPLE_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-256f-robust/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256256FROBUST_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-256f-simple/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256256FSIMPLE_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-256s-robust/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256256SROBUST_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

crypto_sign/sphincs-sha256-256s-simple/avx2/sha256avx.c

@@ -63,9 +63,13 @@ void PQCLEAN_SPHINCSSHA256256SSIMPLE_AVX2_sha256_update8x(sha256ctxx8 *ctx,
         const unsigned char *d7,
         unsigned long long len) {
     unsigned long long i = 0;
+    unsigned long long bytes_to_copy;
 
     while (i < len) {
-        unsigned long long bytes_to_copy = (len - i) > 64 ? 64 : (len - i);
+        bytes_to_copy = len - i;
+        if (bytes_to_copy > 64) {
+            bytes_to_copy = 64;
+        }
         memcpy(&ctx->msgblocks[64 * 0], d0 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 1], d1 + i, bytes_to_copy);
         memcpy(&ctx->msgblocks[64 * 2], d2 + i, bytes_to_copy);

test/test_boolean.py

@@ -0,0 +1,109 @@
+
+"""
+Checks that the implementation does not make use of boolean operations (==, <=, !, etc)
+in assignments or function calls.
+"""
+
+import os
+
+import pytest
+
+import helpers
+import pqclean
+import pycparser
+
+
+def setup_module():
+    if not(os.path.exists(os.path.join('pycparser', '.git'))):
+        print("Please run `git submodule update --init`")
+
+
+class ForbiddenLineVisitor(pycparser.c_ast.NodeVisitor): 
+  def __init__(self):
+    self.errors = []
+
+  def visit_Assignment(self, node): 
+    v = ForbiddenOpVisitor();
+    v.visit(node.rvalue)
+    self.errors.extend(v.errors)
+
+  def visit_Decl(self, node):
+    if node.init:
+        v = ForbiddenOpVisitor();
+        v.visit(node.init)
+        self.errors.extend(v.errors)
+
+  def visit_FuncCall(self, node): 
+    if node.args:
+        v = ForbiddenOpVisitor();
+        v.visit(node.args)
+        self.errors.extend(v.errors)
+
+class ForbiddenOpVisitor(pycparser.c_ast.NodeVisitor): 
+  def __init__(self):
+    self.errors = []
+
+  def visit_BinaryOp(self, node): 
+    v = ForbiddenOpVisitor();
+    v.visit(node.left)
+    self.errors.extend(v.errors)
+    if node.op in ['<', '<=', '>', '>=', '==', '!=', '&&', '||']:
+      err = "\n {} at {c.file}:{c.line}:{c.column}".format(node.op, c=node.coord)
+      self.errors.append(err)
+    v = ForbiddenOpVisitor();
+    v.visit(node.right)
+    self.errors.extend(v.errors)
+
+  def visit_UnaryOp(self, node): 
+    if node.op == '!':
+      err = "\n {} at {c.file}:{c.line}:{c.column}".format(node.op, c=node.coord)
+      self.errors.append(err)
+    v = ForbiddenOpVisitor();
+    v.visit(node.expr)
+    self.errors.extend(v.errors)
+
+  def visit_TernaryOp(self, node): 
+    err = "\n ternary operator at {c.file}:{c.line}:{c.column}".format(c=node.coord)
+    self.errors.append(err)
+
+
+@pytest.mark.parametrize(
+    'implementation',
+    pqclean.Scheme.all_implementations(),
+    ids=str,
+)
+@helpers.skip_windows()
+@helpers.filtered_test
+def test_boolean(implementation):
+    errors = []
+    for fname in os.listdir(implementation.path()):
+        if not fname.endswith(".c"):
+            continue
+        tdir, _ = os.path.split(os.path.realpath(__file__))
+        ast = pycparser.parse_file(
+            os.path.join(implementation.path(), fname),
+            use_cpp=True,
+            cpp_path='cc',  # not all platforms link cpp correctly; cc -E works
+            cpp_args=[
+                '-E',
+                '-std=c99',
+                '-nostdinc',  # pycparser cannot deal with e.g. __attribute__
+                '-I{}'.format(os.path.join(tdir, "../common")),
+                # necessary to mock e.g. <stdint.h>
+                '-I{}'.format(
+                    os.path.join(tdir, 'pycparser/utils/fake_libc_include')),
+            ]
+        )
+        v = ForbiddenLineVisitor()
+        v.visit(ast)
+        errors.extend(v.errors)
+    if errors:
+        raise AssertionError(
+            "Prohibited use of boolean operations in assignment or function call" +
+            "".join(errors)
+        )
+
+
+if __name__ == "__main__":
+    import sys
+    pytest.main(sys.argv)