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authorKees Cook <keescook@chromium.org>2018-09-18 19:10:38 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2018-09-28 12:46:06 +0800
commitb350bee5ea0f4db75d4c6191a2e95db16f40c278 (patch)
tree163e804e6cc008a8d899df4fbc9c894c5b2e056e /crypto
parent3944f139d5592790b70bc64f197162e643a8512b (diff)
crypto: skcipher - Introduce crypto_sync_skcipher
In preparation for removal of VLAs due to skcipher requests on the stack via SKCIPHER_REQUEST_ON_STACK() usage, this introduces the infrastructure for the "sync skcipher" tfm, which is for handling the on-stack cases of skcipher, which are always non-ASYNC and have a known limited request size. The crypto API additions: struct crypto_sync_skcipher (wrapper for struct crypto_skcipher) crypto_alloc_sync_skcipher() crypto_free_sync_skcipher() crypto_sync_skcipher_setkey() crypto_sync_skcipher_get_flags() crypto_sync_skcipher_set_flags() crypto_sync_skcipher_clear_flags() crypto_sync_skcipher_blocksize() crypto_sync_skcipher_ivsize() crypto_sync_skcipher_reqtfm() skcipher_request_set_sync_tfm() SYNC_SKCIPHER_REQUEST_ON_STACK() (with tfm type check) Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/skcipher.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index 0bd8c6caa498..4caab81d2d02 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -949,6 +949,30 @@ struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
}
EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
+struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
+ const char *alg_name, u32 type, u32 mask)
+{
+ struct crypto_skcipher *tfm;
+
+ /* Only sync algorithms allowed. */
+ mask |= CRYPTO_ALG_ASYNC;
+
+ tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
+
+ /*
+ * Make sure we do not allocate something that might get used with
+ * an on-stack request: check the request size.
+ */
+ if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
+ MAX_SYNC_SKCIPHER_REQSIZE)) {
+ crypto_free_skcipher(tfm);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return (struct crypto_sync_skcipher *)tfm;
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
+
int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
{
return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,