From: Ard Biesheuvel <ardb@xxxxxxxxxx>
The ChaCha20-Poly1305 library code uses the sg_miter API to process
input presented via scatterlists, except for the special case where the
digest buffer is not covered entirely by the same scatterlist entry as
the last byte of input. In that case, it uses scatterwalk_map_and_copy()
to access the memory in the input scatterlist where the digest is stored.
This results in a dependency on crypto/scatterwalk.c and therefore on
CONFIG_CRYPTO_ALGAPI, which is unnecessary, as the sg_miter API already
provides this functionality via sg_copy_to_buffer(). So use that
instead, and drop the CRYPTO_ALGAPI dependency.
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
lib/crypto/Kconfig | 1 -
lib/crypto/chacha20poly1305.c | 5 ++---
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index b01253cac70a..a759e6f6a939 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -135,7 +135,6 @@ config CRYPTO_LIB_CHACHA20POLY1305
depends on CRYPTO
select CRYPTO_LIB_CHACHA
select CRYPTO_LIB_POLY1305
- select CRYPTO_ALGAPI
config CRYPTO_LIB_SHA1
tristate
diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c
index a839c0ac60b2..280a4925dd17 100644
--- a/lib/crypto/chacha20poly1305.c
+++ b/lib/crypto/chacha20poly1305.c
@@ -11,7 +11,6 @@
#include <crypto/chacha20poly1305.h>
#include <crypto/chacha.h>
#include <crypto/poly1305.h>
-#include <crypto/scatterwalk.h>
#include <linux/unaligned.h>
#include <linux/kernel.h>
@@ -318,8 +317,8 @@ bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,
if (unlikely(sl > -POLY1305_DIGEST_SIZE)) {
poly1305_final(&poly1305_state, b.mac[1]);
- scatterwalk_map_and_copy(b.mac[encrypt], src, src_len,
- sizeof(b.mac[1]), encrypt);
+ sg_copy_buffer(src, sg_nents(src), b.mac[encrypt],
+ sizeof(b.mac[1]), src_len, !encrypt);
ret = encrypt ||
!crypto_memneq(b.mac[0], b.mac[1], POLY1305_DIGEST_SIZE);
}
--
2.48.1.711.g2feabab25a-goog
