Deleted ECC_ECDSA_VERIFY_ITCH macro. Tweak the corresponding function, and use it.

diff --git a/ChangeLog b/ChangeLog
index 6df6294d1e7337b9e610c9d40f42b2d5ca8428c3..6d7237f9bb2deed97ad08c699c1338f0c731b3bc 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2014-08-28  Niels Möller  <nisse@lysator.liu.se>
 
+       * ecc-internal.h (ECC_ECDSA_VERIFY_ITCH): Deleted macro. Needed
+       scratch depends on curve type, not just size.
+       * ecdsa-verify.c (ecdsa_verify): Use the ecc_ecdsa_verify_itch
+       function, not the corresponding macro.
+       * ecc-ecdsa-verify.c (ecc_ecdsa_verify_itch): Take ecc->mul_itch
+       into account. Also reduce to 5*ecc->size + ecc->mul_itch.
+
        * testsuite/ecdsa-sign-test.c (test_main): Added test for the
        obscure case of ecdsa using curve25519.
 

diff --git a/ecc-ecdsa-verify.c b/ecc-ecdsa-verify.c
index 797e73cda2e9d3db396f7f7d52c637d3dd5c6d17..cc7e0aeff417bb3ee9be0756d07cdb5ba5b5964f 100644 (file)
--- a/ecc-ecdsa-verify.c
+++ b/ecc-ecdsa-verify.c
@@ -62,9 +62,8 @@ ecdsa_in_range (const struct ecc_curve *ecc, const mp_limb_t *xp)
 mp_size_t
 ecc_ecdsa_verify_itch (const struct ecc_curve *ecc)
 {
-  /* Largest storage need is for the ecc_mul_a call, 6 * ecc->size +
-     ECC_MUL_A_ITCH (size) */
-  return ECC_ECDSA_VERIFY_ITCH (ecc->size);
+  /* Largest storage need is for the ecc->mul call. */
+  return 5*ecc->size + ecc->mul_itch;
 }
 
 /* FIXME: Use faster primitives, not requiring side-channel silence. */
@@ -113,7 +112,7 @@ ecc_ecdsa_verify (const struct ecc_curve *ecc,
   /* u2 = r / s, P2 = u2 * Y */
   ecc_modq_mul (ecc, u2, rp, sinv);
 
-   /* Total storage: 5*ecc->size + ECC_MUL_A_ITCH (ecc->size) */
+   /* Total storage: 5*ecc->size + ecc->mul_itch */
   ecc_mul_a (ecc, P2, u2, pp, u2 + ecc->size);
 
   /* u1 = h / s, P1 = u1 * G */
@@ -124,7 +123,7 @@ ecc_ecdsa_verify (const struct ecc_curve *ecc,
      unlikely. */
   if (!zero_p (u1, ecc->size))
     {
-      /* Total storage: 6*ecc->size + ECC_MUL_G_ITCH (ecc->size) */
+      /* Total storage: 6*ecc->size + ecc->mul_g_itch (ecc->size) */
       ecc_mul_g (ecc, P1, u1, u1 + ecc->size);
 
       /* NOTE: ecc_add_jjj and/or ecc_j_to_a will produce garbage in

diff --git a/ecc-internal.h b/ecc-internal.h
index 1fa334aa2333c73afdf9ea030b606655ed22b83f..1e0bb7ec2b280743c0d3e22fbd3473a3bef856a4 100644 (file)
--- a/ecc-internal.h
+++ b/ecc-internal.h
@@ -285,8 +285,6 @@ ecc_25519_sqrt(mp_limb_t *rp, const mp_limb_t *ap);
   (((3 << ECC_MUL_A_EH_WBITS) + 10) * (size))
 #endif
 #define ECC_ECDSA_SIGN_ITCH(size) (12*(size))
-#define ECC_ECDSA_VERIFY_ITCH(size) \
-  (6*(size) + ECC_MUL_A_ITCH ((size)))
 #define ECC_MODQ_RANDOM_ITCH(size) (size)
 #define ECC_HASH_ITCH(size) (1+(size))
 

diff --git a/ecdsa-verify.c b/ecdsa-verify.c
index 62d5e59e20e53b02a8a2438f6e48239f07e641dd..425be5c0e07c998a074f41c4a1322ad62c6365e5 100644 (file)
--- a/ecdsa-verify.c
+++ b/ecdsa-verify.c
@@ -47,7 +47,7 @@ ecdsa_verify (const struct ecc_point *pub,
              const struct dsa_signature *signature)
 {
   mp_limb_t size = pub->ecc->size;
-  mp_size_t itch = 2*size + ECC_ECDSA_VERIFY_ITCH (size);
+  mp_size_t itch = 2*size + ecc_ecdsa_verify_itch (pub->ecc);
   /* For ECC_MUL_A_WBITS == 0, at most 1512 bytes. With
      ECC_MUL_A_WBITS == 4, currently needs 67 * ecc->size, at most
      4824 bytes. Don't use stack allocation for this. */