Make sure your secrets aren't tainted

ed25519-donna-64bit-x86.h

@@ -2,6 +2,14 @@
 
 #define HAVE_GE25519_SCALARMULT_BASE_CHOOSE_NIELS
 
+#ifdef FORCE_SYMVER
+#ifdef __x86_64
+#define TOSTRING(x) #x
+#define STRINGIFY(x) TOSTRING(x) /* Two stages necessary */
+__asm__(".symver memcpy,memcpy@GLIBC_" STRINGIFY(FORCE_SYMVER));
+#endif
+#endif
+
 DONNA_NOINLINE static void
 ge25519_scalarmult_base_choose_niels(ge25519_niels *t, const uint8_t table[256][96], uint32_t pos, signed char b) {
 	int64_t breg = (int64_t)b;

ed25519-donna-impl-base.h

@@ -291,6 +291,8 @@ STATIC void ge25519_double_scalarmult_vartime(ge25519 *r, const ge25519 *p1, con
 
 		ge25519_p1p1_to_partial(r, &t);
 	}
+	expilcit_bzero(slide1, sizeof(slide1));
+	expilcit_bzero(slide2, sizeof(slide2));
 }
 
 /* computes [s1]p1 */
@@ -325,6 +327,7 @@ STATIC void ge25519_scalarmult_vartime(ge25519 *r, const ge25519 *p1, const bign
 
 		ge25519_p1p1_to_partial(r, &t);
 	}
+	expilcit_bzero(slide1, sizeof(slide1));
 }
 
 /*
@@ -440,6 +443,7 @@ STATIC void ge25519_scalarmult(ge25519 *r, const ge25519 *p1, const bignum256mod
 		ge25519_pnielsadd_p1p1(&t, r, &pre, (unsigned char)slide1[i] >> 7);
 		ge25519_p1p1_to_partial(r, &t);
 	}
+	expilcit_bzero(slide1, sizeof(slide1));
 }
 
 #if !defined(HAVE_GE25519_SCALARMULT_BASE_CHOOSE_NIELS)

ed25519-donna-impl-sse2.h

@@ -328,6 +328,8 @@ ge25519_double_scalarmult_vartime(ge25519 *r, const ge25519 *p1, const bignum256
 
 		ge25519_p1p1_to_partial(r, &t);
 	}
+	expilcit_bzero(slide1, sizeof(slide1));
+	expilcit_bzero(slide2, sizeof(slide2));
 }
 
 #ifndef MM16
@@ -368,6 +370,7 @@ ge25519_scalarmult_vartime(ge25519 *r, const ge25519 *p1, const bignum256modm s1
 
 		ge25519_p1p1_to_partial(r, &t);
 	}
+	expilcit_bzero(slide1, sizeof(slide1));
 }
 
 DONNA_INLINE static void ge25519_cmove_stride4(long * r, long * p, long * pos, long * n, int stride) {
@@ -452,6 +455,7 @@ STATIC void ge25519_scalarmult(ge25519 *r, const ge25519 *p1, const bignum256mod
 		ge25519_pnielsadd_p1p1(&t, r, &pre, (unsigned char)slide1[i] >> 7);
 		ge25519_p1p1_to_partial(r, &t);
 	}
+	expilcit_bzero(slide1, sizeof(slide1));
 }
 
 #if !defined(HAVE_GE25519_SCALARMULT_BASE_CHOOSE_NIELS)