| Message ID | 20171122195139.121269-2-ebiggers3@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
On 22 November 2017 at 19:51, Eric Biggers <ebiggers3@gmail.com> wrote: > From: Eric Biggers <ebiggers@google.com> > > The four 32-bit constants for the initial state of ChaCha20 were loaded > from a char array which is not guaranteed to have the needed alignment. > > Fix it by just assigning the constants directly instead. > > Signed-off-by: Eric Biggers <ebiggers@google.com> I'm not thrilled about the open coded hex numbers but I don't care enough to object. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > crypto/chacha20_generic.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c > index 4a45fa4890c0..ec84e7837aac 100644 > --- a/crypto/chacha20_generic.c > +++ b/crypto/chacha20_generic.c > @@ -41,12 +41,10 @@ static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src, > > void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv) > { > - static const char constant[16] = "expand 32-byte k"; > - > - state[0] = le32_to_cpuvp(constant + 0); > - state[1] = le32_to_cpuvp(constant + 4); > - state[2] = le32_to_cpuvp(constant + 8); > - state[3] = le32_to_cpuvp(constant + 12); > + state[0] = 0x61707865; /* "expa" */ > + state[1] = 0x3320646e; /* "nd 3" */ > + state[2] = 0x79622d32; /* "2-by" */ > + state[3] = 0x6b206574; /* "te k" */ > state[4] = ctx->key[0]; > state[5] = ctx->key[1]; > state[6] = ctx->key[2]; > -- > 2.15.0.448.gf294e3d99a-goog >
diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c index 4a45fa4890c0..ec84e7837aac 100644 --- a/crypto/chacha20_generic.c +++ b/crypto/chacha20_generic.c @@ -41,12 +41,10 @@ static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src, void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv) { - static const char constant[16] = "expand 32-byte k"; - - state[0] = le32_to_cpuvp(constant + 0); - state[1] = le32_to_cpuvp(constant + 4); - state[2] = le32_to_cpuvp(constant + 8); - state[3] = le32_to_cpuvp(constant + 12); + state[0] = 0x61707865; /* "expa" */ + state[1] = 0x3320646e; /* "nd 3" */ + state[2] = 0x79622d32; /* "2-by" */ + state[3] = 0x6b206574; /* "te k" */ state[4] = ctx->key[0]; state[5] = ctx->key[1]; state[6] = ctx->key[2];