From: Eric Biggers <ebiggers@kernel.org>
To: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Eric Biggers <ebiggers@kernel.org>
Subject: [PATCH 09/33] crypto: aes - Add CBC and CBC-CTS support using library
Date: Mon, 6 Jul 2026 22:34:39 -0700 [thread overview]
Message-ID: <20260707053503.209874-10-ebiggers@kernel.org> (raw)
In-Reply-To: <20260707053503.209874-1-ebiggers@kernel.org>
Implement the "cbc(aes)" and "cts(cbc(aes))" crypto_skcipher algorithms
using the corresponding library functions.
Among other benefits, this allows the architecture-optimized AES-CBC and
AES-CBC-CTS code to be migrated into the library while still leaving it
accessible via crypto_skcipher, eliminating lots of boilerplate code.
For now the cra_priority is set to just 110, since the
architecture-optimized implementations of these algorithms haven't yet
been migrated into the library. It will be boosted once that happens.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
crypto/Kconfig | 1 +
crypto/aes.c | 163 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 164 insertions(+)
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 093508d13b8c..3d30d79878c2 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -358,6 +358,7 @@ config CRYPTO_AES
tristate "AES (Advanced Encryption Standard)"
select CRYPTO_ALGAPI
select CRYPTO_LIB_AES
+ select CRYPTO_LIB_AES_CBC if CRYPTO_CBC || CRYPTO_CTS
select CRYPTO_LIB_AES_CBC_MACS if CRYPTO_CMAC || CRYPTO_XCBC || CRYPTO_CCM
select CRYPTO_LIB_AES_ECB if CRYPTO_ECB
select CRYPTO_HASH if CRYPTO_CMAC || CRYPTO_XCBC || CRYPTO_CCM
diff --git a/crypto/aes.c b/crypto/aes.c
index 162715a82be3..5999f8117ce7 100644
--- a/crypto/aes.c
+++ b/crypto/aes.c
@@ -6,6 +6,7 @@
*/
#include <crypto/aes-cbc-macs.h>
+#include <crypto/aes-cbc.h>
#include <crypto/aes-ecb.h>
#include <crypto/aes.h>
#include <crypto/algapi.h>
@@ -328,6 +329,128 @@ static __maybe_unused int crypto_aes_ecb_decrypt(struct skcipher_request *req)
return 0;
}
+/* AES-CBC */
+
+static void crypto_aes_cbc_encrypt_sg(struct scatterlist *dst,
+ struct scatterlist *src,
+ unsigned int cryptlen,
+ u8 iv[AES_BLOCK_SIZE],
+ const struct aes_key *key)
+{
+ AES_CRYPT_SG(aes_cbc_encrypt, dst, src, cryptlen, 0, iv, key);
+}
+
+static void crypto_aes_cbc_decrypt_sg(struct scatterlist *dst,
+ struct scatterlist *src,
+ unsigned int cryptlen,
+ u8 iv[AES_BLOCK_SIZE],
+ const struct aes_key *key)
+{
+ AES_CRYPT_SG(aes_cbc_decrypt, dst, src, cryptlen, 0, iv, key);
+}
+
+static __maybe_unused int crypto_aes_cbc_encrypt(struct skcipher_request *req)
+{
+ const struct aes_key *key =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+
+ if (unlikely(req->cryptlen % AES_BLOCK_SIZE))
+ return -EINVAL;
+ crypto_aes_cbc_encrypt_sg(req->dst, req->src, req->cryptlen, req->iv,
+ key);
+ return 0;
+}
+
+static __maybe_unused int crypto_aes_cbc_decrypt(struct skcipher_request *req)
+{
+ const struct aes_key *key =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+
+ if (unlikely(req->cryptlen % AES_BLOCK_SIZE))
+ return -EINVAL;
+ crypto_aes_cbc_decrypt_sg(req->dst, req->src, req->cryptlen, req->iv,
+ key);
+ return 0;
+}
+
+/* AES-CBC-CTS */
+
+static noinline int
+crypto_aes_cbc_cts_crypt_nonlinear(struct skcipher_request *req, bool enc)
+{
+ const struct aes_key *key =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+ unsigned int main_len = req->cryptlen;
+ unsigned int tail_len =
+ ((main_len - 1) % AES_BLOCK_SIZE) + 1 + AES_BLOCK_SIZE;
+ u8 tmp[2 * AES_BLOCK_SIZE] __aligned(__alignof__(long));
+
+ if (main_len == AES_BLOCK_SIZE) {
+ /* Single block is a special case that just does CBC. */
+ if (enc)
+ crypto_aes_cbc_encrypt_sg(req->dst, req->src, main_len,
+ req->iv, key);
+ else
+ crypto_aes_cbc_decrypt_sg(req->dst, req->src, main_len,
+ req->iv, key);
+ return 0;
+ }
+ /* Just do the last two blocks separately. */
+ main_len -= tail_len;
+ if (enc)
+ crypto_aes_cbc_encrypt_sg(req->dst, req->src, main_len, req->iv,
+ key);
+ else
+ crypto_aes_cbc_decrypt_sg(req->dst, req->src, main_len, req->iv,
+ key);
+ memcpy_from_sglist(tmp, req->src, main_len, tail_len);
+ if (enc)
+ aes_cbc_cts_encrypt(tmp, tmp, tail_len, req->iv, key);
+ else
+ aes_cbc_cts_decrypt(tmp, tmp, tail_len, req->iv, key);
+ memcpy_to_sglist(req->dst, main_len, tmp, tail_len);
+ memzero_explicit(tmp, sizeof(tmp));
+ return 0;
+}
+
+static __maybe_unused int
+crypto_aes_cbc_cts_encrypt(struct skcipher_request *req)
+{
+ const struct aes_key *key =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+
+ if (unlikely(req->cryptlen < AES_BLOCK_SIZE))
+ return -EINVAL;
+ if (!IS_ENABLED(CONFIG_HIGHMEM) &&
+ likely(req->src->length >= req->cryptlen &&
+ req->dst->length >= req->cryptlen)) {
+ /* Fast path */
+ aes_cbc_cts_encrypt(sg_virt(req->dst), sg_virt(req->src),
+ req->cryptlen, req->iv, key);
+ return 0;
+ }
+ return crypto_aes_cbc_cts_crypt_nonlinear(req, /* enc= */ true);
+}
+
+static __maybe_unused int
+crypto_aes_cbc_cts_decrypt(struct skcipher_request *req)
+{
+ const struct aes_key *key =
+ crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+
+ if (unlikely(req->cryptlen < AES_BLOCK_SIZE))
+ return -EINVAL;
+ if (!IS_ENABLED(CONFIG_HIGHMEM) &&
+ likely(req->src->length >= req->cryptlen &&
+ req->dst->length >= req->cryptlen)) {
+ /* Fast path */
+ aes_cbc_cts_decrypt(sg_virt(req->dst), sg_virt(req->src),
+ req->cryptlen, req->iv, key);
+ return 0;
+ }
+ return crypto_aes_cbc_cts_crypt_nonlinear(req, /* enc= */ false);
+}
+
static struct skcipher_alg skcipher_algs[] = {
#if IS_ENABLED(CONFIG_CRYPTO_ECB)
{
@@ -344,6 +467,38 @@ static struct skcipher_alg skcipher_algs[] = {
.decrypt = crypto_aes_ecb_decrypt,
},
#endif
+#if IS_ENABLED(CONFIG_CRYPTO_CBC)
+ {
+ .base.cra_name = "cbc(aes)",
+ .base.cra_driver_name = "cbc-aes-lib",
+ .base.cra_priority = 110,
+ .base.cra_blocksize = AES_BLOCK_SIZE,
+ .base.cra_ctxsize = sizeof(struct aes_key),
+ .base.cra_module = THIS_MODULE,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = crypto_aes_skcipher_setkey,
+ .encrypt = crypto_aes_cbc_encrypt,
+ .decrypt = crypto_aes_cbc_decrypt,
+ },
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_CTS)
+ {
+ .base.cra_name = "cts(cbc(aes))",
+ .base.cra_driver_name = "cts-cbc-aes-lib",
+ .base.cra_priority = 110,
+ .base.cra_blocksize = AES_BLOCK_SIZE,
+ .base.cra_ctxsize = sizeof(struct aes_key),
+ .base.cra_module = THIS_MODULE,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = crypto_aes_skcipher_setkey,
+ .encrypt = crypto_aes_cbc_cts_encrypt,
+ .decrypt = crypto_aes_cbc_cts_decrypt,
+ },
+#endif
};
static int __init crypto_aes_mod_init(void)
@@ -408,3 +563,11 @@ MODULE_ALIAS_CRYPTO("cbcmac-aes-lib");
MODULE_ALIAS_CRYPTO("ecb(aes)");
MODULE_ALIAS_CRYPTO("ecb-aes-lib");
#endif
+#if IS_ENABLED(CONFIG_CRYPTO_CBC)
+MODULE_ALIAS_CRYPTO("cbc(aes)");
+MODULE_ALIAS_CRYPTO("cbc-aes-lib");
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_CTS)
+MODULE_ALIAS_CRYPTO("cts(cbc(aes))");
+MODULE_ALIAS_CRYPTO("cts-cbc-aes-lib");
+#endif
--
2.54.0
next prev parent reply other threads:[~2026-07-07 5:37 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-07 5:34 [PATCH 00/33] Library APIs for AES encryption modes Eric Biggers
2026-07-07 5:34 ` [PATCH 01/33] crypto: xts - Split out __xts_verify_key() helper Eric Biggers
2026-07-07 13:20 ` Thomas Huth
2026-07-07 5:34 ` [PATCH 02/33] lib/crypto: aes: Add ECB support Eric Biggers
2026-07-07 13:59 ` Thomas Huth
2026-07-07 19:22 ` Eric Biggers
2026-07-08 5:29 ` Thomas Huth
2026-07-07 5:34 ` [PATCH 03/33] lib/crypto: aes: Add CBC and CBC-CTS support Eric Biggers
2026-07-07 5:34 ` [PATCH 04/33] lib/crypto: aes: Add CTR and XCTR support Eric Biggers
2026-07-07 5:34 ` [PATCH 05/33] lib/crypto: aes: Add XTS support Eric Biggers
2026-07-07 5:34 ` [PATCH 06/33] lib/crypto: aes: Add GCM support Eric Biggers
2026-07-07 5:34 ` [PATCH 07/33] lib/crypto: aes: Add CCM support Eric Biggers
2026-07-07 5:34 ` [PATCH 08/33] crypto: aes - Add ECB support using library Eric Biggers
2026-07-07 5:34 ` Eric Biggers [this message]
2026-07-07 5:34 ` [PATCH 10/33] crypto: aes - Add CTR and XCTR " Eric Biggers
2026-07-07 5:34 ` [PATCH 11/33] crypto: aes - Add XTS " Eric Biggers
2026-07-07 5:34 ` [PATCH 12/33] crypto: aes - Add GCM " Eric Biggers
2026-07-07 5:34 ` [PATCH 13/33] crypto: aes - Add CCM " Eric Biggers
2026-07-07 5:34 ` [PATCH 14/33] x86/sev: Use new AES-GCM library Eric Biggers
2026-07-07 5:34 ` [PATCH 15/33] lib/crypto: aesgcm: Remove old " Eric Biggers
2026-07-07 5:34 ` [PATCH 16/33] crypto: aes - Remove AES-CBC-MAC support Eric Biggers
2026-07-07 5:34 ` [PATCH 17/33] lib/crypto: aes: Remove aes_cbcmac_* functions Eric Biggers
2026-07-07 5:34 ` [PATCH 18/33] fscrypt: Use aes_ecb_encrypt() for v1 key derivation Eric Biggers
2026-07-07 5:34 ` [PATCH 19/33] KEYS: encrypted: Use AES-CBC library instead of crypto_skcipher Eric Biggers
2026-07-07 5:34 ` [PATCH 20/33] KEYS: trusted: dcp: Use AES-GCM library instead of crypto_aead Eric Biggers
2026-07-07 5:34 ` [PATCH 21/33] libceph: Use AES-CBC library in ceph_aes_crypt() Eric Biggers
2026-07-07 5:34 ` [PATCH 22/33] libceph: Reimplement messenger v2 encryption using AES-GCM library Eric Biggers
2026-07-07 5:34 ` [PATCH 23/33] wifi: mac80211: Use AES-CTR library in fils_aead.c Eric Biggers
2026-07-07 5:34 ` [PATCH 24/33] wifi: mac80211: Use AES-GCM library for GMAC suite Eric Biggers
2026-07-07 5:34 ` [PATCH 25/33] wifi: mac80211: Use crypto libraries for GCMP and CCMP suites Eric Biggers
2026-07-07 5:34 ` [PATCH 26/33] macsec: Use AES-GCM library instead of crypto_aead Eric Biggers
2026-07-07 5:34 ` [PATCH 27/33] wifi: ipw2x00: Use AES-CCM library Eric Biggers
2026-07-07 5:34 ` [PATCH 28/33] mac802154: Use AES-CCM and AES-CTR libraries Eric Biggers
2026-07-07 5:34 ` [PATCH 29/33] bpf: crypto: Use AES-CBC and AES-ECB libraries Eric Biggers
2026-07-07 15:01 ` Vadim Fedorenko
2026-07-07 18:20 ` Eric Biggers
2026-07-07 22:50 ` Vadim Fedorenko
2026-07-07 23:16 ` Eric Biggers
2026-07-08 11:47 ` Vadim Fedorenko
2026-07-07 5:35 ` [PATCH 30/33] bpf: crypto: Add AES-GCM support Eric Biggers
2026-07-07 15:02 ` Vadim Fedorenko
2026-07-07 5:35 ` [PATCH 31/33] smb: client: Use AES-GCM and AES-CCM libraries Eric Biggers
2026-07-07 5:35 ` [PATCH 32/33] ksmbd: " Eric Biggers
2026-07-07 10:51 ` Namjae Jeon
2026-07-07 5:35 ` [PATCH 33/33] net: tipc: Use AES-GCM library instead of crypto_aead Eric Biggers
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