Merge pull request #439 from libtom/radix-code-cleanup

mp_radix off-by-one error and other related code-cleanup

Author: sjaeckel

demo/test.c

@@ -1138,7 +1138,7 @@ static int test_mp_read_radix(void)
 
    DO(mp_read_radix(&a, "123456", 10));
 
-   DO(mp_to_radix(&a, buf, SIZE_MAX, &written, 10));
+   DO(mp_to_radix(&a, buf, sizeof(buf), &written, 10));
    printf(" '123456' a == %s, length = %zu", buf, written);
 
    /* See comment in mp_to_radix.c */
@@ -1153,11 +1153,11 @@ static int test_mp_read_radix(void)
              buf, written, mp_error_to_string(err));
    */
    DO(mp_read_radix(&a, "-123456", 10));
-   DO(mp_to_radix(&a, buf, SIZE_MAX, &written, 10));
+   DO(mp_to_radix(&a, buf, sizeof(buf), &written, 10));
    printf("\r '-123456' a == %s, length = %zu", buf, written);
 
    DO(mp_read_radix(&a, "0", 10));
-   DO(mp_to_radix(&a, buf, SIZE_MAX, &written, 10));
+   DO(mp_to_radix(&a, buf, sizeof(buf), &written, 10));
    printf("\r '0' a == %s, length = %zu", buf, written);
 
    while (0) {
@@ -1335,7 +1335,7 @@ static int test_mp_reduce_2k_l(void)
    mp_int a, b, c, d;
    int cnt;
    char buf[4096];
-   size_t length[1];
+   size_t length;
    DOR(mp_init_multi(&a, &b, NULL));
    /* test the mp_reduce_2k_l code */
 #      if LTM_DEMO_TEST_REDUCE_2K_L == 1
@@ -1353,9 +1353,8 @@ static int test_mp_reduce_2k_l(void)
 #      else
 #         error oops
 #      endif
-   *length = sizeof(buf);
-   DO(mp_to_radix(&a, buf, length, 10));
-   printf("\n\np==%s, length = %zu\n", buf, *length);
+   DO(mp_to_radix(&a, buf, sizeof(buf), &length, 10));
+   printf("\n\np==%s, length = %zu\n", buf, length);
    /* now mp_reduce_is_2k_l() should return */
    if (mp_reduce_is_2k_l(&a) != 1) {
       printf("mp_reduce_is_2k_l() return 0, should be 1\n");

mp_fread.c

@@ -35,14 +35,14 @@ mp_err mp_fread(mp_int *a, int radix, FILE *stream)
       uint8_t y;
       unsigned pos;
       ch = (radix <= 36) ? MP_TOUPPER(ch) : ch;
-      pos = (unsigned)(ch - (int)'(');
-      if (MP_RMAP_REVERSE_SIZE < pos) {
+      pos = (unsigned)(ch - (int)'+');
+      if (MP_RMAP_REVERSE_SIZE <= pos) {
          break;
       }
 
       y = s_mp_rmap_reverse[pos];
 
-      if ((y == 0xff) || (y >= radix)) {
+      if (y >= radix) {
          break;
       }
 

mp_radix_smap.c

@@ -6,17 +6,14 @@
 /* chars used in radix conversions */
 const char s_mp_rmap[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/";
 const uint8_t s_mp_rmap_reverse[] = {
-   0xff, 0xff, 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f, /* ()*+,-./ */
-   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 01234567 */
-   0x08, 0x09, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 89:;<=>? */
-   0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, /* @ABCDEFG */
-   0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, /* HIJKLMNO */
-   0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, /* PQRSTUVW */
-   0x21, 0x22, 0x23, 0xff, 0xff, 0xff, 0xff, 0xff, /* XYZ[\]^_ */
-   0xff, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, /* `abcdefg */
-   0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, /* hijklmno */
-   0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, /* pqrstuvw */
-   0x3b, 0x3c, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, /* xyz{|}~. */
+   0x3e, 0xff, 0xff, 0xff, 0x3f, 0x00, 0x01, 0x02, 0x03, 0x04, /* +,-./01234 */
+   0x05, 0x06, 0x07, 0x08, 0x09, 0xff, 0xff, 0xff, 0xff, 0xff, /* 56789:;<=> */
+   0xff, 0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, /* ?@ABCDEFGH */
+   0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, /* IJKLMNOPQR */
+   0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0xff, 0xff, /* STUVWXYZ[\ */
+   0xff, 0xff, 0xff, 0xff, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, /* ]^_`abcdef */
+   0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, /* ghijklmnop */
+   0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d  /* qrstuvwxyz */
 };
 MP_STATIC_ASSERT(correct_rmap_reverse_size, sizeof(s_mp_rmap_reverse) == MP_RMAP_REVERSE_SIZE)
 #endif

mp_read_radix.c

@@ -33,8 +33,8 @@ mp_err mp_read_radix(mp_int *a, const char *str, int radix)
        */
       uint8_t y;
       char ch = (radix <= 36) ? (char)MP_TOUPPER((int)*str) : *str;
-      unsigned pos = (unsigned)(ch - '(');
-      if (MP_RMAP_REVERSE_SIZE < pos) {
+      unsigned pos = (unsigned)(ch - '+');
+      if (MP_RMAP_REVERSE_SIZE <= pos) {
          break;
       }
       y = s_mp_rmap_reverse[pos];
@@ -43,7 +43,7 @@ mp_err mp_read_radix(mp_int *a, const char *str, int radix)
        * and is less than the given radix add it
        * to the number, otherwise exit the loop.
        */
-      if ((y == 0xff) || (y >= radix)) {
+      if (y >= radix) {
          break;
       }
       if ((err = mp_mul_d(a, (mp_digit)radix, a)) != MP_OKAY) {

tommath_private.h

@@ -193,7 +193,7 @@ MP_PRIVATE void s_mp_copy_digs(mp_digit *d, const mp_digit *s, int digits);
 MP_PRIVATE mp_err s_mp_rand_jenkins(void *p, size_t n) MP_WUR;
 MP_PRIVATE void s_mp_rand_jenkins_init(uint64_t seed);
 
-#define MP_RMAP_REVERSE_SIZE 88u
+#define MP_RMAP_REVERSE_SIZE 80u
 extern MP_PRIVATE const char s_mp_rmap[];
 extern MP_PRIVATE const uint8_t s_mp_rmap_reverse[];
 extern MP_PRIVATE const mp_digit s_mp_prime_tab[];