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authorJack Lloyd <[email protected]>2016-08-31 10:31:58 -0400
committerJack Lloyd <[email protected]>2016-08-31 10:31:58 -0400
commit148262088c117ba849efc42432f2d2510ce25349 (patch)
tree663bf183b9ce54f08530f319fd4b491473514f61 /src/lib/pubkey/curve25519/donna.cpp
parent5e946f93e8e751d2104f58583d4f209ca631aff1 (diff)
parentee60a29088fc6dd712c1651af1e7f56a26f40d63 (diff)
Merge GH #567/GH #457 TLS refactoring and Callbacks interface
Diffstat (limited to 'src/lib/pubkey/curve25519/donna.cpp')
-rw-r--r--src/lib/pubkey/curve25519/donna.cpp76
1 files changed, 46 insertions, 30 deletions
diff --git a/src/lib/pubkey/curve25519/donna.cpp b/src/lib/pubkey/curve25519/donna.cpp
index 9b28e412c..a0e4d249f 100644
--- a/src/lib/pubkey/curve25519/donna.cpp
+++ b/src/lib/pubkey/curve25519/donna.cpp
@@ -39,6 +39,26 @@ typedef byte u8;
typedef u64bit limb;
typedef limb felem[5];
+typedef struct
+ {
+ limb* x;
+ limb* z;
+ } fmonty_pair_t;
+
+typedef struct
+ {
+ fmonty_pair_t q;
+ fmonty_pair_t q_dash;
+ const limb* q_minus_q_dash;
+ } fmonty_in_t;
+
+typedef struct
+ {
+ fmonty_pair_t two_q;
+ fmonty_pair_t q_plus_q_dash;
+ } fmonty_out_t;
+
+
#if !defined(BOTAN_TARGET_HAS_NATIVE_UINT128)
typedef donna128 uint128_t;
#endif
@@ -273,44 +293,41 @@ fcontract(u8 *output, const felem input) {
/* Input: Q, Q', Q-Q'
* Output: 2Q, Q+Q'
*
- * x2 z3: long form
- * x3 z3: long form
- * x z: short form, destroyed
- * xprime zprime: short form, destroyed
- * qmqp: short form, preserved
+ * result.two_q (2*Q): long form
+ * result.q_plus_q_dash (Q + Q): long form
+ * in.q: short form, destroyed
+ * in.q_dash: short form, destroyed
+ * in.q_minus_q_dash: short form, preserved
*/
static void
-fmonty(limb *x2, limb *z2, /* output 2Q */
- limb *x3, limb *z3, /* output Q + Q' */
- limb *x, limb *z, /* input Q */
- limb *xprime, limb *zprime, /* input Q' */
- const limb *qmqp /* input Q - Q' */) {
+fmonty(fmonty_out_t& result, fmonty_in_t& in)
+{
limb origx[5], origxprime[5], zzz[5], xx[5], zz[5], xxprime[5],
- zzprime[5], zzzprime[5];
+ zzprime[5], zzzprime[5];
- copy_mem(origx, x, 5);
- fsum(x, z);
- fdifference_backwards(z, origx); // does x - z
+ copy_mem(origx, in.q.x, 5);
+ fsum(in.q.x, in.q.z);
+ fdifference_backwards(in.q.z, origx); // does x - z
- copy_mem(origxprime, xprime, 5);
- fsum(xprime, zprime);
- fdifference_backwards(zprime, origxprime);
- fmul(xxprime, xprime, z);
- fmul(zzprime, x, zprime);
+ copy_mem(origxprime, in.q_dash.x, 5);
+ fsum(in.q_dash.x, in.q_dash.z);
+ fdifference_backwards(in.q_dash.z, origxprime);
+ fmul(xxprime, in.q_dash.x, in.q.z);
+ fmul(zzprime, in.q.x, in.q_dash.z);
copy_mem(origxprime, xxprime, 5);
fsum(xxprime, zzprime);
fdifference_backwards(zzprime, origxprime);
- fsquare_times(x3, xxprime, 1);
+ fsquare_times(result.q_plus_q_dash.x, xxprime, 1);
fsquare_times(zzzprime, zzprime, 1);
- fmul(z3, zzzprime, qmqp);
+ fmul(result.q_plus_q_dash.z, zzzprime, in.q_minus_q_dash);
- fsquare_times(xx, x, 1);
- fsquare_times(zz, z, 1);
- fmul(x2, xx, zz);
+ fsquare_times(xx, in.q.x, 1);
+ fsquare_times(zz, in.q.z, 1);
+ fmul(result.two_q.x, xx, zz);
fdifference_backwards(zz, xx); // does zz = xx - zz
fscalar_product(zzz, zz, 121665);
fsum(zzz, xx);
- fmul(z2, zz, zzz);
+ fmul(result.two_q.z, zz, zzz);
}
// -----------------------------------------------------------------------------
@@ -356,11 +373,10 @@ cmult(limb *resultx, limb *resultz, const u8 *n, const limb *q) {
swap_conditional(nqx, nqpqx, bit);
swap_conditional(nqz, nqpqz, bit);
- fmonty(nqx2, nqz2,
- nqpqx2, nqpqz2,
- nqx, nqz,
- nqpqx, nqpqz,
- q);
+
+ fmonty_out_t result { nqx2, nqz2, nqpqx2, nqpqz2 };
+ fmonty_in_t in { nqx, nqz, nqpqx, nqpqz, q };
+ fmonty(result, in);
swap_conditional(nqx2, nqpqx2, bit);
swap_conditional(nqz2, nqpqz2, bit);