Update NSS to 3.21 RTM and NSPR to 4.11 RTM

nss/lib/freebl/mpi/mpi.c

Index: nss/lib/freebl/mpi/mpi.c
diff --git a/nss/lib/freebl/mpi/mpi.c b/nss/lib/freebl/mpi/mpi.c
index 2a3719b88367d8924767822d4fdcb2bf2bcc97b2..84f9b97b63ea408c8a85ddd52b38b88ba12863f3 100644
--- a/nss/lib/freebl/mpi/mpi.c
+++ b/nss/lib/freebl/mpi/mpi.c
@@ -1095,7 +1095,7 @@ mp_err mp_expt(mp_int *a, mp_int *b, mp_int *c)
   mp_int   s, x;
   mp_err   res;
   mp_digit d;
-  int      dig, bit;
+  unsigned int      dig, bit;
 
   ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG);
 
@@ -1470,7 +1470,7 @@ mp_err s_mp_exptmod(const mp_int *a, const mp_int *b, const mp_int *m, mp_int *c
   mp_int   s, x, mu;
   mp_err   res;
   mp_digit d;
-  int      dig, bit;
+  unsigned int      dig, bit;
 
   ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG);
 
@@ -2004,7 +2004,7 @@ mp_size mp_trailing_zeros(const mp_int *mp)
 {
   mp_digit d;
   mp_size  n = 0;
-  int      ix;
+  unsigned int      ix;
 
   if (!mp || !MP_DIGITS(mp) || !mp_cmp_z(mp))
     return n;
@@ -2916,8 +2916,7 @@ void     s_mp_exch(mp_int *a, mp_int *b)
 mp_err   s_mp_lshd(mp_int *mp, mp_size p)
 {
   mp_err  res;
-  mp_size pos;
-  int     ix;
+  unsigned int     ix;
 
   if(p == 0)
     return MP_OKAY;
@@ -2928,14 +2927,13 @@ mp_err   s_mp_lshd(mp_int *mp, mp_size p)
   if((res = s_mp_pad(mp, USED(mp) + p)) != MP_OKAY)
     return res;
 
-  pos = USED(mp) - 1;
-
   /* Shift all the significant figures over as needed */
-  for(ix = pos - p; ix >= 0; ix--) 
+  for (ix = USED(mp) - p; ix-- > 0;) {
     DIGIT(mp, ix + p) = DIGIT(mp, ix);
+  }
 
   /* Fill the bottom digits with zeroes */
-  for(ix = 0; ix < p; ix++)
+  for(ix = 0; (mp_size)ix < p; ix++)
     DIGIT(mp, ix) = 0;
 
   return MP_OKAY;
@@ -3046,7 +3044,7 @@ void     s_mp_div_2(mp_int *mp)
 mp_err s_mp_mul_2(mp_int *mp)
 {
   mp_digit *pd;
-  int      ix, used;
+  unsigned int ix, used;
   mp_digit kin = 0;
 
   /* Shift digits leftward by 1 bit */
@@ -4192,6 +4190,7 @@ mp_err   s_mp_div(mp_int *rem, 	/* i: dividend, o: remainder */
 
   MP_SIGN(rem) = ZPOS;
   MP_SIGN(div) = ZPOS;
+  MP_SIGN(&part) = ZPOS;
 
   /* A working temporary for division     */
   MP_CHECKOK( mp_init_size(&t, MP_ALLOC(rem)));
@@ -4199,8 +4198,6 @@ mp_err   s_mp_div(mp_int *rem, 	/* i: dividend, o: remainder */
   /* Normalize to optimize guessing       */
   MP_CHECKOK( s_mp_norm(rem, div, &d) );
 
-  part = *rem;
-
   /* Perform the division itself...woo!   */
   MP_USED(quot) = MP_ALLOC(quot);
 
@@ -4209,11 +4206,15 @@ mp_err   s_mp_div(mp_int *rem, 	/* i: dividend, o: remainder */
   while (MP_USED(rem) > MP_USED(div) || s_mp_cmp(rem, div) >= 0) {
     int i;
     int unusedRem;
+    int partExtended = 0;  /* set to true if we need to extend part */
 
     unusedRem = MP_USED(rem) - MP_USED(div);
     MP_DIGITS(&part) = MP_DIGITS(rem) + unusedRem;
     MP_ALLOC(&part)  = MP_ALLOC(rem)  - unusedRem;
     MP_USED(&part)   = MP_USED(div);
+
+    /* We have now truncated the part of the remainder to the same length as
+     * the divisor. If part is smaller than div, extend part by one digit. */
     if (s_mp_cmp(&part, div) < 0) {
       -- unusedRem;
 #if MP_ARGCHK == 2
@@ -4222,26 +4223,34 @@ mp_err   s_mp_div(mp_int *rem, 	/* i: dividend, o: remainder */
       -- MP_DIGITS(&part);
       ++ MP_USED(&part);
       ++ MP_ALLOC(&part);
+      partExtended = 1;
     }
 
     /* Compute a guess for the next quotient digit       */
     q_msd = MP_DIGIT(&part, MP_USED(&part) - 1);
     div_msd = MP_DIGIT(div, MP_USED(div) - 1);
-    if (q_msd >= div_msd) {
+    if (!partExtended) {
+      /* In this case, q_msd /= div_msd is always 1. First, since div_msd is
+       * normalized to have the high bit set, 2*div_msd > MP_DIGIT_MAX. Since
+       * we didn't extend part, q_msd >= div_msd. Therefore we know that
+       * div_msd <= q_msd <= MP_DIGIT_MAX < 2*div_msd. Dividing by div_msd we
+       * get 1 <= q_msd/div_msd < 2. So q_msd /= div_msd must be 1. */
       q_msd = 1;
-    } else if (MP_USED(&part) > 1) {
+    } else {
 #if !defined(MP_NO_MP_WORD) && !defined(MP_NO_DIV_WORD)
       q_msd = (q_msd << MP_DIGIT_BIT) | MP_DIGIT(&part, MP_USED(&part) - 2);
       q_msd /= div_msd;
       if (q_msd == RADIX)
         --q_msd;
 #else
-      mp_digit r;
-      MP_CHECKOK( s_mpv_div_2dx1d(q_msd, MP_DIGIT(&part, MP_USED(&part) - 2), 
-				  div_msd, &q_msd, &r) );
+      if (q_msd == div_msd) {
+        q_msd = MP_DIGIT_MAX;
+      } else {
+        mp_digit r;
+        MP_CHECKOK( s_mpv_div_2dx1d(q_msd, MP_DIGIT(&part, MP_USED(&part) - 2),
+				    div_msd, &q_msd, &r) );
+      }
 #endif
-    } else {
-      q_msd = 0;
     }
 #if MP_ARGCHK == 2
     assert(q_msd > 0); /* This case should never occur any more. */
@@ -4672,10 +4681,10 @@ mp_read_unsigned_octets(mp_int *mp, const unsigned char *str, mp_size len)
 /* }}} */
 
 /* {{{ mp_unsigned_octet_size(mp) */
-int    
+unsigned int
 mp_unsigned_octet_size(const mp_int *mp)
 {
-  int  bytes;
+  unsigned int bytes;
   int  ix;
   mp_digit  d = 0;
 
@@ -4712,12 +4721,12 @@ mp_err
 mp_to_unsigned_octets(const mp_int *mp, unsigned char *str, mp_size maxlen)
 {
   int  ix, pos = 0;
-  int  bytes;
+  unsigned int  bytes;
 
   ARGCHK(mp != NULL && str != NULL && !SIGN(mp), MP_BADARG);
 
   bytes = mp_unsigned_octet_size(mp);
-  ARGCHK(bytes >= 0 && bytes <= maxlen, MP_BADARG);
+  ARGCHK(bytes <= maxlen, MP_BADARG);
 
   /* Iterate over each digit... */
   for(ix = USED(mp) - 1; ix >= 0; ix--) {
@@ -4744,12 +4753,12 @@ mp_err
 mp_to_signed_octets(const mp_int *mp, unsigned char *str, mp_size maxlen)
 {
   int  ix, pos = 0;
-  int  bytes;
+  unsigned int  bytes;
 
   ARGCHK(mp != NULL && str != NULL && !SIGN(mp), MP_BADARG);
 
   bytes = mp_unsigned_octet_size(mp);
-  ARGCHK(bytes >= 0 && bytes <= maxlen, MP_BADARG);
+  ARGCHK(bytes <= maxlen, MP_BADARG);
 
   /* Iterate over each digit... */
   for(ix = USED(mp) - 1; ix >= 0; ix--) {
@@ -4784,12 +4793,12 @@ mp_err
 mp_to_fixlen_octets(const mp_int *mp, unsigned char *str, mp_size length)
 {
   int  ix, pos = 0;
-  int  bytes;
+  unsigned int  bytes;
 
   ARGCHK(mp != NULL && str != NULL && !SIGN(mp), MP_BADARG);
 
   bytes = mp_unsigned_octet_size(mp);
-  ARGCHK(bytes >= 0 && bytes <= length, MP_BADARG);
+  ARGCHK(bytes <= length, MP_BADARG);
 
   /* place any needed leading zeros */
   for (;length > bytes; --length) {