Commit c85bb680 authored by Nick Mathewson's avatar Nick Mathewson 🥔
Browse files

Make curve25519-donna work with our compiler warnings.

parent 9c3c571c

src/ext/curve25519_donna/curve25519-donna-c64.c

+2 −0
Original line number Diff line number Diff line
@@ -401,6 +401,8 @@ crecip(felem out, const felem z) { 
  /* 2^255 - 21 */ fmul(out, t0, a);

}



int curve25519_donna(u8 *, const u8 *, const u8 *);



int

curve25519_donna(u8 *mypublic, const u8 *secret, const u8 *basepoint) {

  limb bp[5], x[5], z[5], zmone[5];

src/ext/curve25519_donna/curve25519-donna.c

+18 −12
Original line number Diff line number Diff line
@@ -238,7 +238,7 @@ static inline limb 
div_by_2_26(const limb v)

{

  /* High word of v; no shift needed*/

  const uint32_t highword = ((uint64_t) v) >> 32;

  const uint32_t highword = (uint32_t) (((uint64_t) v) >> 32);

  /* Set to all 1s if v was negative; else set to 0s. */

  const int32_t sign = ((int32_t) highword) >> 31;

  /* Set to 0x3ffffff if v was negative; else set to 0. */
@@ -252,7 +252,7 @@ static inline limb 
div_by_2_25(const limb v)

{

  /* High word of v; no shift needed*/

  const uint32_t highword = ((uint64_t) v) >> 32;

  const uint32_t highword = (uint32_t) (((uint64_t) v) >> 32);

  /* Set to all 1s if v was negative; else set to 0s. */

  const int32_t sign = ((int32_t) highword) >> 31;

  /* Set to 0x1ffffff if v was negative; else set to 0. */
@@ -305,7 +305,7 @@ static void freduce_coefficients(limb *output) { 
   * So |over| will be no more than 1. */

  {

    /* output[1] fits in 32 bits, so we can use div_s32_by_2_25 here. */

    s32 over32 = div_s32_by_2_25(output[1]);

    s32 over32 = div_s32_by_2_25((s32) output[1]);

    output[1] -= over32 << 25;

    output[2] += over32;

  }
@@ -446,11 +446,13 @@ fcontract(u8 *output, limb *input) { 
        input[i+1] = (s32)(input[i+1]) - carry;

      }

    }

    {

      const s32 mask = (s32)(input[9]) >> 31;

      const s32 carry = -(((s32)(input[9]) & mask) >> 25);

      input[9] = (s32)(input[9]) + (carry << 25);

      input[0] = (s32)(input[0]) - (carry * 19);

    }

  }



  /* The first borrow-propagation pass above ended with every limb

     except (possibly) input[0] non-negative.
@@ -462,10 +464,12 @@ fcontract(u8 *output, limb *input) { 
     were all zero.  In that case, input[1] is now 2^25 - 1, and this

     last borrow-propagation step will leave input[1] non-negative.

  */

  {

    const s32 mask = (s32)(input[0]) >> 31;

    const s32 carry = -(((s32)(input[0]) & mask) >> 26);

    input[0] = (s32)(input[0]) + (carry << 26);

    input[1] = (s32)(input[1]) - carry;

  }



  /* Both passes through the above loop, plus the last 0-to-1 step, are

     necessary: if input[9] is -1 and input[0] through input[8] are 0,
@@ -571,7 +575,7 @@ static void fmonty(limb *x2, limb *z2, /* output 2Q */ 
static void

swap_conditional(limb a[19], limb b[19], limb iswap) {

  unsigned i;

  const s32 swap = -iswap;

  const s32 swap = (s32) -iswap;



  for (i = 0; i < 10; ++i) {

    const s32 x = swap & ( ((s32)a[i]) ^ ((s32)b[i]) );
@@ -703,6 +707,8 @@ crecip(limb *out, const limb *z) { 
  /* 2^255 - 21 */ fmul(out,t1,z11);

}



int curve25519_donna(u8 *, const u8 *, const u8 *);



int

curve25519_donna(u8 *mypublic, const u8 *secret, const u8 *basepoint) {

  limb bp[10], x[10], z[11], zmone[10];