This patch adds support for the AES-XTS skcipher algorithm.

Signed-off-by: Pascal van Leeuwen <pvanleeu...@verimatrix.com>
---
 drivers/crypto/inside-secure/safexcel.c        |   1 +
 drivers/crypto/inside-secure/safexcel.h        |   2 +
 drivers/crypto/inside-secure/safexcel_cipher.c | 102 ++++++++++++++++++++++++-
 3 files changed, 101 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/inside-secure/safexcel.c 
b/drivers/crypto/inside-secure/safexcel.c
index ca84119..45443bf 100644
--- a/drivers/crypto/inside-secure/safexcel.c
+++ b/drivers/crypto/inside-secure/safexcel.c
@@ -1004,6 +1004,7 @@ static int safexcel_request_ring_irq(void *pdev, int 
irqid,
        &safexcel_alg_authenc_hmac_sha256_ctr_aes,
        &safexcel_alg_authenc_hmac_sha384_ctr_aes,
        &safexcel_alg_authenc_hmac_sha512_ctr_aes,
+       &safexcel_alg_xts_aes,
 };

 static int safexcel_register_algorithms(struct safexcel_crypto_priv *priv)
diff --git a/drivers/crypto/inside-secure/safexcel.h 
b/drivers/crypto/inside-secure/safexcel.h
index 6687ff9..dcc060c 100644
--- a/drivers/crypto/inside-secure/safexcel.h
+++ b/drivers/crypto/inside-secure/safexcel.h
@@ -329,6 +329,7 @@ struct safexcel_context_record {
 #define CONTEXT_CONTROL_CRYPTO_MODE_ECB                (0 << 0)
 #define CONTEXT_CONTROL_CRYPTO_MODE_CBC                (1 << 0)
 #define CONTEXT_CONTROL_CRYPTO_MODE_CTR_LOAD   (6 << 0)
+#define CONTEXT_CONTROL_CRYPTO_MODE_XTS                (7 << 0)
 #define CONTEXT_CONTROL_IV0                    BIT(5)
 #define CONTEXT_CONTROL_IV1                    BIT(6)
 #define CONTEXT_CONTROL_IV2                    BIT(7)
@@ -744,5 +745,6 @@ int safexcel_hmac_setkey(const char *alg, const u8 *key, 
unsigned int keylen,
 extern struct safexcel_alg_template safexcel_alg_authenc_hmac_sha256_ctr_aes;
 extern struct safexcel_alg_template safexcel_alg_authenc_hmac_sha384_ctr_aes;
 extern struct safexcel_alg_template safexcel_alg_authenc_hmac_sha512_ctr_aes;
+extern struct safexcel_alg_template safexcel_alg_xts_aes;

 #endif
diff --git a/drivers/crypto/inside-secure/safexcel_cipher.c 
b/drivers/crypto/inside-secure/safexcel_cipher.c
index 45b83a3..d65e5f7 100644
--- a/drivers/crypto/inside-secure/safexcel_cipher.c
+++ b/drivers/crypto/inside-secure/safexcel_cipher.c
@@ -39,9 +39,9 @@ struct safexcel_cipher_ctx {
        enum safexcel_cipher_alg alg;
        bool aead;

-       __le32 key[8];
+       __le32 key[16];
        u32 nonce;
-       unsigned int key_len;
+       unsigned int key_len, xts;

        /* All the below is AEAD specific */
        u32 hash_alg;
@@ -368,7 +368,7 @@ static int safexcel_context_control(struct 
safexcel_cipher_ctx *ctx,
        } else if (ctx->alg == SAFEXCEL_3DES) {
                cdesc->control_data.control0 |= CONTEXT_CONTROL_CRYPTO_ALG_3DES;
        } else if (ctx->alg == SAFEXCEL_AES) {
-               switch (ctx->key_len) {
+               switch (ctx->key_len >> ctx->xts) {
                case AES_KEYSIZE_128:
                        cdesc->control_data.control0 |= 
CONTEXT_CONTROL_CRYPTO_ALG_AES128;
                        break;
@@ -380,7 +380,7 @@ static int safexcel_context_control(struct 
safexcel_cipher_ctx *ctx,
                        break;
                default:
                        dev_err(priv->dev, "aes keysize not supported: %u\n",
-                               ctx->key_len);
+                               ctx->key_len >> ctx->xts);
                        return -EINVAL;
                }
        }
@@ -1769,3 +1769,97 @@ struct safexcel_alg_template 
safexcel_alg_authenc_hmac_sha384_ctr_aes = {
                },
        },
 };
+
+static int safexcel_skcipher_aesxts_setkey(struct crypto_skcipher *ctfm,
+                                          const u8 *key, unsigned int len)
+{
+       struct crypto_tfm *tfm = crypto_skcipher_tfm(ctfm);
+       struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+       struct safexcel_crypto_priv *priv = ctx->priv;
+       struct crypto_aes_ctx aes;
+       int ret, i;
+       unsigned int keylen;
+
+       /* Only half of the key data is cipher key */
+       keylen = (len >> 1) + (len & 1);
+       ret = crypto_aes_expand_key(&aes, key, keylen);
+       if (ret) {
+               crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+               return ret;
+       }
+
+       if (priv->flags & EIP197_TRC_CACHE && ctx->base.ctxr_dma) {
+               for (i = 0; i < keylen / sizeof(u32); i++) {
+                       if (ctx->key[i] != cpu_to_le32(aes.key_enc[i])) {
+                               ctx->base.needs_inv = true;
+                               break;
+                       }
+               }
+       }
+
+       for (i = 0; i < keylen / sizeof(u32); i++)
+               ctx->key[i] = cpu_to_le32(aes.key_enc[i]);
+
+       /* The other half is the tweak key */
+       ret = crypto_aes_expand_key(&aes, (u8 *)(key + keylen), keylen);
+       if (ret) {
+               crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+               return ret;
+       }
+
+       if (priv->flags & EIP197_TRC_CACHE && ctx->base.ctxr_dma) {
+               for (i = 0; i < keylen / sizeof(u32); i++) {
+                       if (ctx->key[i + keylen / sizeof(u32)] !=
+                           cpu_to_le32(aes.key_enc[i])) {
+                               ctx->base.needs_inv = true;
+                               break;
+                       }
+               }
+       }
+
+       for (i = 0; i < keylen / sizeof(u32); i++)
+               ctx->key[i + keylen / sizeof(u32)] =
+                       cpu_to_le32(aes.key_enc[i]);
+
+       ctx->key_len = keylen << 1;
+
+       memzero_explicit(&aes, sizeof(aes));
+       return 0;
+}
+
+static int safexcel_skcipher_aes_xts_cra_init(struct crypto_tfm *tfm)
+{
+       struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+       safexcel_skcipher_cra_init(tfm);
+       ctx->alg  = SAFEXCEL_AES;
+       ctx->xts  = 1;
+       ctx->mode = CONTEXT_CONTROL_CRYPTO_MODE_XTS;
+       return 0;
+}
+
+struct safexcel_alg_template safexcel_alg_xts_aes = {
+       .type = SAFEXCEL_ALG_TYPE_SKCIPHER,
+       .alg.skcipher = {
+               .setkey = safexcel_skcipher_aesxts_setkey,
+               .encrypt = safexcel_encrypt,
+               .decrypt = safexcel_decrypt,
+               /* Add 4 to include the 4 byte nonce! */
+               .min_keysize = AES_MIN_KEY_SIZE * 2,
+               .max_keysize = AES_MAX_KEY_SIZE * 2,
+               .ivsize = 16,
+               .base = {
+                       .cra_name = "xts(aes)",
+                       .cra_driver_name = "safexcel-xts-aes",
+                       .cra_priority = 300,
+                       .cra_flags = CRYPTO_ALG_ASYNC |
+                                    CRYPTO_ALG_KERN_DRIVER_ONLY,
+                       .cra_blocksize = 1,
+                       .cra_ctxsize = sizeof(struct safexcel_cipher_ctx),
+                       .cra_alignmask = 0,
+                       .cra_init = safexcel_skcipher_aes_xts_cra_init,
+                       .cra_exit = safexcel_skcipher_cra_exit,
+                       .cra_module = THIS_MODULE,
+               },
+       },
+};
--
1.8.3.1

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