The sha1-ce finup implementation for ARM64 produces wrong digest
for empty input (len=0). Expected: da39a3ee..., result: 67452301...
(initial value of SHA internal state). The error is in sha1_ce_finup:
for empty data `finalize` will be 1, so the code is relying on
sha1_ce_transform to make the final round. However, in
sha1_base_do_update, the block function will not be called when
len == 0.
Fix it by setting finalize to 0 if data is empty.
Fixes: 07eb54d306f4 ("crypto: arm64/sha1-ce - move SHA-1 ARMv8 implementation to base layer")
Cc: [email protected]
Signed-off-by: Elena Petrova <[email protected]>
---
arch/arm64/crypto/sha1-ce-glue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/crypto/sha1-ce-glue.c b/arch/arm64/crypto/sha1-ce-glue.c
index eaa7a8258f1c..0652f5f07ed1 100644
--- a/arch/arm64/crypto/sha1-ce-glue.c
+++ b/arch/arm64/crypto/sha1-ce-glue.c
@@ -55,7 +55,7 @@ static int sha1_ce_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
struct sha1_ce_state *sctx = shash_desc_ctx(desc);
- bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE);
+ bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE) && len;
if (!crypto_simd_usable())
return crypto_sha1_finup(desc, data, len, out);
--
2.22.0.rc1.257.g3120a18244-goog
On Tue, 28 May 2019 at 14:42, Elena Petrova <[email protected]> wrote:
>
> The sha1-ce finup implementation for ARM64 produces wrong digest
> for empty input (len=0). Expected: da39a3ee..., result: 67452301...
> (initial value of SHA internal state). The error is in sha1_ce_finup:
> for empty data `finalize` will be 1, so the code is relying on
> sha1_ce_transform to make the final round. However, in
> sha1_base_do_update, the block function will not be called when
> len == 0.
>
> Fix it by setting finalize to 0 if data is empty.
>
> Fixes: 07eb54d306f4 ("crypto: arm64/sha1-ce - move SHA-1 ARMv8 implementation to base layer")
> Cc: [email protected]
> Signed-off-by: Elena Petrova <[email protected]>
Thanks for the fix
Reviewed-by: Ard Biesheuvel <[email protected]>
It looks like the sha224/256 suffers from the same issue. Would you
mind sending out a fix for that as well? Thanks.
> ---
> arch/arm64/crypto/sha1-ce-glue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/crypto/sha1-ce-glue.c b/arch/arm64/crypto/sha1-ce-glue.c
> index eaa7a8258f1c..0652f5f07ed1 100644
> --- a/arch/arm64/crypto/sha1-ce-glue.c
> +++ b/arch/arm64/crypto/sha1-ce-glue.c
> @@ -55,7 +55,7 @@ static int sha1_ce_finup(struct shash_desc *desc, const u8 *data,
> unsigned int len, u8 *out)
> {
> struct sha1_ce_state *sctx = shash_desc_ctx(desc);
> - bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE);
> + bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE) && len;
>
> if (!crypto_simd_usable())
> return crypto_sha1_finup(desc, data, len, out);
> --
> 2.22.0.rc1.257.g3120a18244-goog
>
Yep, sha2 also has the bug, I'll be sending the fix soon, thanks!
On Tue, 28 May 2019 at 14:03, Ard Biesheuvel <[email protected]> wrote:
>
> On Tue, 28 May 2019 at 14:42, Elena Petrova <[email protected]> wrote:
> >
> > The sha1-ce finup implementation for ARM64 produces wrong digest
> > for empty input (len=0). Expected: da39a3ee..., result: 67452301...
> > (initial value of SHA internal state). The error is in sha1_ce_finup:
> > for empty data `finalize` will be 1, so the code is relying on
> > sha1_ce_transform to make the final round. However, in
> > sha1_base_do_update, the block function will not be called when
> > len == 0.
> >
> > Fix it by setting finalize to 0 if data is empty.
> >
> > Fixes: 07eb54d306f4 ("crypto: arm64/sha1-ce - move SHA-1 ARMv8 implementation to base layer")
> > Cc: [email protected]
> > Signed-off-by: Elena Petrova <[email protected]>
>
> Thanks for the fix
>
> Reviewed-by: Ard Biesheuvel <[email protected]>
>
> It looks like the sha224/256 suffers from the same issue. Would you
> mind sending out a fix for that as well? Thanks.
>
> > ---
> > arch/arm64/crypto/sha1-ce-glue.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/crypto/sha1-ce-glue.c b/arch/arm64/crypto/sha1-ce-glue.c
> > index eaa7a8258f1c..0652f5f07ed1 100644
> > --- a/arch/arm64/crypto/sha1-ce-glue.c
> > +++ b/arch/arm64/crypto/sha1-ce-glue.c
> > @@ -55,7 +55,7 @@ static int sha1_ce_finup(struct shash_desc *desc, const u8 *data,
> > unsigned int len, u8 *out)
> > {
> > struct sha1_ce_state *sctx = shash_desc_ctx(desc);
> > - bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE);
> > + bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE) && len;
> >
> > if (!crypto_simd_usable())
> > return crypto_sha1_finup(desc, data, len, out);
> > --
> > 2.22.0.rc1.257.g3120a18244-goog
> >
On Tue, May 28, 2019 at 01:41:52PM +0100, Elena Petrova wrote:
> The sha1-ce finup implementation for ARM64 produces wrong digest
> for empty input (len=0). Expected: da39a3ee..., result: 67452301...
> (initial value of SHA internal state). The error is in sha1_ce_finup:
> for empty data `finalize` will be 1, so the code is relying on
> sha1_ce_transform to make the final round. However, in
> sha1_base_do_update, the block function will not be called when
> len == 0.
>
> Fix it by setting finalize to 0 if data is empty.
>
> Fixes: 07eb54d306f4 ("crypto: arm64/sha1-ce - move SHA-1 ARMv8 implementation to base layer")
> Cc: [email protected]
> Signed-off-by: Elena Petrova <[email protected]>
> Reviewed-by: Ard Biesheuvel <[email protected]>
> ---
> arch/arm64/crypto/sha1-ce-glue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt