wg: curve25519: handle unaligned loads/stores safely

Reported-by: Chris Hewitt <chris@chrishewitt.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2018-12-20 18:30:21 +01:00
parent 89662178c6
commit 53f9023e7e
2 changed files with 19 additions and 5 deletions

View file

@ -39,9 +39,23 @@ typedef int64_t s64;
#define le32_to_cpup(a) (*(a)) #define le32_to_cpup(a) (*(a))
#define cpu_to_le64(a) (a) #define cpu_to_le64(a) (a)
#endif #endif
#define get_unaligned_le32(a) le32_to_cpup((u32 *)(a)) static inline __le32 get_unaligned_le32(const u8 *a)
#define get_unaligned_le64(a) le64_to_cpup((u64 *)(a)) {
#define put_unaligned_le64(s, d) *(u64 *)(d) = cpu_to_le64(s) __le32 l;
__builtin_memcpy(&l, a, sizeof(l));
return le32_to_cpup(&l);
}
static inline __le64 get_unaligned_le64(const u8 *a)
{
__le64 l;
__builtin_memcpy(&l, a, sizeof(l));
return le64_to_cpup(&l);
}
static inline void put_unaligned_le64(u64 s, u8 *d)
{
__le64 l = cpu_to_le64(s);
__builtin_memcpy(d, &l, sizeof(l));
}
#ifndef __always_inline #ifndef __always_inline
#define __always_inline __inline __attribute__((__always_inline__)) #define __always_inline __inline __attribute__((__always_inline__))
#endif #endif
@ -70,7 +84,7 @@ static noinline void memzero_explicit(void *s, size_t count)
void curve25519_generate_public(uint8_t pub[static CURVE25519_KEY_SIZE], const uint8_t secret[static CURVE25519_KEY_SIZE]) void curve25519_generate_public(uint8_t pub[static CURVE25519_KEY_SIZE], const uint8_t secret[static CURVE25519_KEY_SIZE])
{ {
static const uint8_t basepoint[CURVE25519_KEY_SIZE] = { 9 }; static const uint8_t basepoint[CURVE25519_KEY_SIZE] __aligned(sizeof(uintptr_t)) = { 9 };
curve25519(pub, secret, basepoint); curve25519(pub, secret, basepoint);
} }

View file

@ -13,7 +13,7 @@
int pubkey_main(int argc, char *argv[]) int pubkey_main(int argc, char *argv[])
{ {
uint8_t key[WG_KEY_LEN]; uint8_t key[WG_KEY_LEN] __attribute__((aligned(sizeof(uintptr_t))));
char base64[WG_KEY_LEN_BASE64]; char base64[WG_KEY_LEN_BASE64];
int trailing_char; int trailing_char;