Merge pull request #349 from czurnieden/sans_eight

Remove support for 8-bit (MP_8BIT)

Author: sjaeckel

bn_mp_from_ubin.c

@@ -23,15 +23,8 @@ mp_err mp_from_ubin(mp_int *a, const unsigned char *buf, size_t size)
       if ((err = mp_mul_2d(a, 8, a)) != MP_OKAY) {
          return err;
       }
-
-#ifndef MP_8BIT
       a->dp[0] |= *buf++;
       a->used += 1;
-#else
-      a->dp[0] = (*buf & MP_MASK);
-      a->dp[1] |= ((*buf++ >> 7) & 1u);
-      a->used += 2;
-#endif
    }
    mp_clamp(a);
    return MP_OKAY;

bn_mp_montgomery_setup.c

@@ -24,10 +24,8 @@ mp_err mp_montgomery_setup(const mp_int *n, mp_digit *rho)
 
    x = (((b + 2u) & 4u) << 1) + b; /* here x*a==1 mod 2**4 */
    x *= 2u - (b * x);              /* here x*a==1 mod 2**8 */
-#if !defined(MP_8BIT)
    x *= 2u - (b * x);              /* here x*a==1 mod 2**16 */
-#endif
-#if defined(MP_64BIT) || !(defined(MP_8BIT) || defined(MP_16BIT))
+#if defined(MP_64BIT) || !(defined(MP_16BIT))
    x *= 2u - (b * x);              /* here x*a==1 mod 2**32 */
 #endif
 #ifdef MP_64BIT

bn_mp_prime_frobenius_underwood.c

@@ -9,7 +9,6 @@
  */
 #ifndef LTM_USE_ONLY_MR
 
-#ifdef MP_8BIT
 /*
  * floor of positive solution of
  * (2^16)-1 = (a+4)*(2*a+5)
@@ -19,10 +18,8 @@
  *       But it is still a restriction of the set of available pseudoprimes
  *       which makes this implementation less secure if used stand-alone.
  */
-#define LTM_FROBENIUS_UNDERWOOD_A 177
-#else
 #define LTM_FROBENIUS_UNDERWOOD_A 32764
-#endif
+
 mp_err mp_prime_frobenius_underwood(const mp_int *N, mp_bool *result)
 {
    mp_int T1z, T2z, Np1z, sz, tz;

bn_mp_prime_is_prime.c

@@ -57,13 +57,6 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result)
          return MP_OKAY;
       }
    }
-#ifdef MP_8BIT
-   /* The search in the loop above was exhaustive in this case */
-   if ((a->used == 1) && (MP_PRIME_TAB_SIZE >= 31)) {
-      return MP_OKAY;
-   }
-#endif
-
    /* first perform trial division */
    if ((err = s_mp_prime_is_divisible(a, &res)) != MP_OKAY) {
       return err;
@@ -112,7 +105,7 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result)
        * MP_8BIT (It is unknown if the Lucas-Selfridge test works with 16-bit
        * integers but the necesssary analysis is on the todo-list).
        */
-#if defined (MP_8BIT) || defined (LTM_USE_FROBENIUS_TEST)
+#ifdef LTM_USE_FROBENIUS_TEST
       err = mp_prime_frobenius_underwood(a, &res);
       if ((err != MP_OKAY) && (err != MP_ITER)) {
          goto LBL_B;
@@ -240,20 +233,6 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result)
           * an unsigned int and "mask" on the other side is most probably not.
           */
          fips_rand = (unsigned int)(b.dp[0] & (mp_digit) mask);
-#ifdef MP_8BIT
-         /*
-          * One 8-bit digit is too small, so concatenate two if the size of
-          * unsigned int allows for it.
-          */
-         if ((MP_SIZEOF_BITS(unsigned int)/2) >= MP_SIZEOF_BITS(mp_digit)) {
-            if ((err = mp_rand(&b, 1)) != MP_OKAY) {
-               goto LBL_B;
-            }
-            fips_rand <<= MP_SIZEOF_BITS(mp_digit);
-            fips_rand |= (unsigned int) b.dp[0];
-            fips_rand &= mask;
-         }
-#endif
          if (fips_rand > (unsigned int)(INT_MAX - MP_DIGIT_BIT)) {
             len = INT_MAX / MP_DIGIT_BIT;
          } else {
@@ -264,18 +243,6 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result)
             ix--;
             continue;
          }
-         /*
-          * As mentioned above, one 8-bit digit is too small and
-          * although it can only happen in the unlikely case that
-          * an "unsigned int" is smaller than 16 bit a simple test
-          * is cheap and the correction even cheaper.
-          */
-#ifdef MP_8BIT
-         /* All "a" < 2^8 have been caught before */
-         if (len == 1) {
-            len++;
-         }
-#endif
          if ((err = mp_rand(&b, len)) != MP_OKAY) {
             goto LBL_B;
          }

bn_mp_prime_strong_lucas_selfridge.c

@@ -9,12 +9,6 @@
  */
 #ifndef LTM_USE_ONLY_MR
 
-/*
- *  8-bit is just too small. You can try the Frobenius test
- *  but that frobenius test can fail, too, for the same reason.
- */
-#ifndef MP_8BIT
-
 /*
  * multiply bigint a with int d and put the result in c
  * Like mp_mul_d() but with a signed long as the small input
@@ -286,4 +280,3 @@ mp_err mp_prime_strong_lucas_selfridge(const mp_int *a, mp_bool *result)
 }
 #endif
 #endif
-#endif

bn_mp_to_ubin.c

@@ -20,11 +20,7 @@ mp_err mp_to_ubin(const mp_int *a, unsigned char *buf, size_t maxlen, size_t *wr
    }
 
    for (x = count; x --> 0u;) {
-#ifndef MP_8BIT
       buf[x] = (unsigned char)(t.dp[0] & 255u);
-#else
-      buf[x] = (unsigned char)(t.dp[0] | ((t.dp[1] & 1u) << 7));
-#endif
       if ((err = mp_div_2d(&t, 8, &t, NULL)) != MP_OKAY) {
          goto LBL_ERR;
       }

bn_prime_tab.c

@@ -7,9 +7,7 @@ const mp_digit s_mp_prime_tab[] = {
    0x0002, 0x0003, 0x0005, 0x0007, 0x000B, 0x000D, 0x0011, 0x0013,
    0x0017, 0x001D, 0x001F, 0x0025, 0x0029, 0x002B, 0x002F, 0x0035,
    0x003B, 0x003D, 0x0043, 0x0047, 0x0049, 0x004F, 0x0053, 0x0059,
-   0x0061, 0x0065, 0x0067, 0x006B, 0x006D, 0x0071, 0x007F,
-#ifndef MP_8BIT
-   0x0083,
+   0x0061, 0x0065, 0x0067, 0x006B, 0x006D, 0x0071, 0x007F, 0x0083,
    0x0089, 0x008B, 0x0095, 0x0097, 0x009D, 0x00A3, 0x00A7, 0x00AD,
    0x00B3, 0x00B5, 0x00BF, 0x00C1, 0x00C5, 0x00C7, 0x00D3, 0x00DF,
    0x00E3, 0x00E5, 0x00E9, 0x00EF, 0x00F1, 0x00FB, 0x0101, 0x0107,
@@ -41,7 +39,6 @@ const mp_digit s_mp_prime_tab[] = {
    0x05BF, 0x05C9, 0x05CB, 0x05CF, 0x05D1, 0x05D5, 0x05DB, 0x05E7,
    0x05F3, 0x05FB, 0x0607, 0x060D, 0x0611, 0x0617, 0x061F, 0x0623,
    0x062B, 0x062F, 0x063D, 0x0641, 0x0647, 0x0649, 0x064D, 0x0653
-#endif
 };
 
 #endif

demo/shared.c

@@ -23,9 +23,6 @@ void ndraw(mp_int *a, const char *name)
 
 void print_header(void)
 {
-#ifdef MP_8BIT
-   printf("Digit size 8 Bit \n");
-#endif
 #ifdef MP_16BIT
    printf("Digit size 16 Bit \n");
 #endif

demo/test.c

@@ -1022,7 +1022,6 @@ static int test_mp_prime_is_prime(void)
 
    }
    /* Check regarding problem #143 */
-#ifndef MP_8BIT
    mp_read_radix(&a,
                  "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A63A3620FFFFFFFFFFFFFFFF",
                  16);
@@ -1041,8 +1040,6 @@ static int test_mp_prime_is_prime(void)
       putchar('\n');
       goto LBL_ERR;
    }
-#endif
-
    printf("\n\n");
 
    mp_clear_multi(&a, &b, NULL);
@@ -2040,17 +2037,9 @@ static int test_mp_root_u32(void)
    if ((e = mp_init_multi(&a, &c, &r, NULL)) != MP_OKAY) {
       return EXIT_FAILURE;
    }
-#ifdef MP_8BIT
-   for (i = 0; i < 1; i++) {
-#else
    for (i = 0; i < 10; i++) {
-#endif
       mp_read_radix(&a, input[i], 64);
-#ifdef MP_8BIT
-      for (j = 3; j < 10; j++) {
-#else
       for (j = 3; j < 100; j++) {
-#endif
          mp_root_u32(&a, (uint32_t)j, &c);
          mp_read_radix(&r, root[i][j-3], 10);
          if (mp_cmp(&r, &c) != MP_EQ) {

doc/bn.tex

@@ -2035,9 +2035,7 @@ \section{Frobenius (Underwood)  Test}
 \begin{alltt}
 int mp_prime_frobenius_underwood(const mp_int *N, int *result)
 \end{alltt}
-Performs the variant of the Frobenius test as described by Paul Underwood. The single internal use is in
-\texttt{mp\_prime\_is\_prime} for \texttt{MP\_8BIT} only but can be included at build-time for all other sizes
-if the preprocessor macro \texttt{LTM\_USE\_FROBENIUS\_TEST} is defined.
+Performs the variant of the Frobenius test as described by Paul Underwood. It can be included at build-time if the preprocessor macro \texttt{LTM\_USE\_FROBENIUS\_TEST} is defined and will be used instead of the Lucas-Selfridge test.
 
 It returns \texttt{MP\_ITER} if the number of iterations is exhausted, assumes a composite as the input and sets \texttt{result} accordingly. This will reduce the set of available pseudoprimes by a very small amount: test with large datasets (more than $10^{10}$ numbers, both randomly chosen and sequences of odd numbers with a random start point) found only 31 (thirty-one) numbers with $a > 120$ and none at all with just an additional simple check for divisors $d < 2^8$.
 
@@ -2053,7 +2051,7 @@ \section{Primality Testing}
 \begin{alltt}
 int mp_prime_is_prime (mp_int * a, int t, int *result)
 \end{alltt}
-This will perform a trial division followed by two rounds of Miller-Rabin with bases 2 and 3 and a Lucas-Selfridge test. The Lucas-Selfridge test is replaced with a Frobenius-Underwood for \texttt{MP\_8BIT}. The Frobenius-Underwood test for all other sizes is available as a compile-time option with the preprocessor macro \texttt{LTM\_USE\_FROBENIUS\_TEST}. See file
+This will perform a trial division followed by two rounds of Miller-Rabin with bases 2 and 3 and a Lucas-Selfridge test. The Frobenius-Underwood is available as a compile-time option with the preprocessor macro \texttt{LTM\_USE\_FROBENIUS\_TEST}. See file
 \texttt{bn\_mp\_prime\_is\_prime.c} for the necessary details. It shall be noted that both functions are much slower than
 the Miller-Rabin test and if speed is an essential issue, the macro \texttt{LTM\_USE\_ONLY\_MR} switches both functions, the Frobenius-Underwood test and the Lucas-Selfridge test off and their code will not even be compiled into the library.
 

mtest/mtest.c

@@ -28,11 +28,7 @@ mulmod
 
  */
 
-#ifdef MP_8BIT
-#define THE_MASK 127
-#else
 #define THE_MASK 32767
-#endif
 
 #include <stdio.h>
 #include <stdlib.h>

testme.sh

@@ -378,13 +378,11 @@ do
     then
       _runvalgrind "$i $a" "$CFLAGS"
       [ "$WITH_LOW_MP" != "1" ] && continue
-      _runvalgrind "$i $a" "-DMP_8BIT $CFLAGS"
       _runvalgrind "$i $a" "-DMP_16BIT $CFLAGS"
       _runvalgrind "$i $a" "-DMP_32BIT $CFLAGS"
     else
       _runtest "$i $a" "$CFLAGS"
       [ "$WITH_LOW_MP" != "1" ] && continue
-      _runtest "$i $a" "-DMP_8BIT $CFLAGS"
       _runtest "$i $a" "-DMP_16BIT $CFLAGS"
       _runtest "$i $a" "-DMP_32BIT $CFLAGS"
     fi

tommath.h

@@ -6,6 +6,10 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#ifdef MP_8BIT
+#  error "Support of 8-bit architectures has been dropped in this version of LTM."
+#endif
+
 
 #ifndef MP_NO_FILE
 #  include <stdio.h>
@@ -35,7 +39,7 @@ extern "C" {
     defined(__sparcv9) || defined(__sparc_v9__) || defined(__sparc64__) || \
     defined(__ia64) || defined(__ia64__) || defined(__itanium__) || defined(_M_IA64) || \
     defined(__LP64__) || defined(_LP64) || defined(__64BIT__)
-#   if !(defined(MP_64BIT) || defined(MP_32BIT) || defined(MP_16BIT) || defined(MP_8BIT))
+#   if !(defined(MP_64BIT) || defined(MP_32BIT) || defined(MP_16BIT))
 #      if defined(__GNUC__) && !defined(__hppa)
 /* we support 128bit integers only via: __attribute__((mode(TI))) */
 #         define MP_64BIT
@@ -47,7 +51,7 @@ extern "C" {
 #endif
 
 #ifdef MP_DIGIT_BIT
-#   error Defining MP_DIGIT_BIT is disallowed, use MP_8/16/31/32/64BIT
+#   error Defining MP_DIGIT_BIT is disallowed, use MP_16/31/32/64BIT
 #endif
 
 /* some default configurations.
@@ -59,11 +63,8 @@ extern "C" {
  * [any size beyond that is ok provided it doesn't overflow the data type]
  */
 
-#ifdef MP_8BIT
-typedef uint8_t              mp_digit;
-typedef uint16_t             private_mp_word;
-#   define MP_DIGIT_BIT 7
-#elif defined(MP_16BIT)
+
+#if defined(MP_16BIT)
 typedef uint16_t             mp_digit;
 typedef uint32_t             private_mp_word;
 #   define MP_DIGIT_BIT 15