[PATCH 2/3] crypto: cipher - Add crypto_clone_cipher
From: "Herbert Xu" <herbert@gondor.apana.org.au>
Date: 2023-05-19 08:29:20
Also in:
linux-crypto, lkml
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
Allow simple ciphers to be cloned, if they don't have a cra_init function. This basically rules out those ciphers that require a fallback. In future simple ciphers will be eliminated, and replaced with a linear skcipher interface. When that happens this restriction will disappear. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> --- crypto/cipher.c | 23 +++++++++++++++++++++++ include/crypto/internal/cipher.h | 2 ++ 2 files changed, 25 insertions(+)
diff --git a/crypto/cipher.c b/crypto/cipher.c
index b47141ed4a9f..d39ef5f72ab8 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c@@ -90,3 +90,26 @@ void crypto_cipher_decrypt_one(struct crypto_cipher *tfm, cipher_crypt_one(tfm, dst, src, false); } EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, CRYPTO_INTERNAL); + +struct crypto_cipher *crypto_clone_cipher(struct crypto_cipher *cipher) +{ + struct crypto_tfm *tfm = crypto_cipher_tfm(cipher); + struct crypto_alg *alg = tfm->__crt_alg; + struct crypto_cipher *ncipher; + struct crypto_tfm *ntfm; + + if (alg->cra_init) + return ERR_PTR(-ENOSYS); + + ntfm = __crypto_alloc_tfm(alg, CRYPTO_ALG_TYPE_CIPHER, + CRYPTO_ALG_TYPE_MASK); + if (IS_ERR(ntfm)) + return ERR_CAST(ntfm); + + ntfm->crt_flags = tfm->crt_flags; + + ncipher = __crypto_cipher_cast(ntfm); + + return ncipher; +} +EXPORT_SYMBOL_GPL(crypto_clone_cipher);
diff --git a/include/crypto/internal/cipher.h b/include/crypto/internal/cipher.h
index a9174ba90250..5030f6d2df31 100644
--- a/include/crypto/internal/cipher.h
+++ b/include/crypto/internal/cipher.h@@ -176,6 +176,8 @@ void crypto_cipher_encrypt_one(struct crypto_cipher *tfm, void crypto_cipher_decrypt_one(struct crypto_cipher *tfm, u8 *dst, const u8 *src); +struct crypto_cipher *crypto_clone_cipher(struct crypto_cipher *cipher); + struct crypto_cipher_spawn { struct crypto_spawn base; };