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driver: skcipher: add fallback for 192-bit keys
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Signed-off-by: Ovidiu Panait <[email protected]>
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@ovpanait
ovpanait committed Aug 15, 2021
1 parent 784d1ec commit 24e9d37
Showing 1 changed file with 77 additions and 6 deletions.
83 changes: 77 additions & 6 deletions driver/zynqaes_skcipher.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,9 @@

struct zynqaes_skcipher_ctx {
struct zynqaes_ctx base;

struct crypto_sync_skcipher *fallback_tfm;
bool need_fallback;
};

struct zynqaes_skcipher_reqctx {
Expand Down Expand Up @@ -132,6 +135,27 @@ static int zynqaes_skcipher_enqueue_next_dma_op(struct zynqaes_skcipher_reqctx *
return ret;
}

static int zynqaes_skcipher_fallback(struct skcipher_request *areq, int encrypt)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
struct zynqaes_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback_tfm);
int err;

skcipher_request_set_sync_tfm(subreq, ctx->fallback_tfm);
skcipher_request_set_callback(subreq, areq->base.flags,
areq->base.complete, areq->base.data);
skcipher_request_set_crypt(subreq, areq->src, areq->dst, areq->cryptlen,
areq->iv);

if (encrypt)
err = crypto_skcipher_encrypt(subreq);
else
err = crypto_skcipher_decrypt(subreq);

return err;
}

static int zynqaes_skcipher_crypt_req(struct crypto_engine *engine,
void *req)
{
Expand Down Expand Up @@ -174,9 +198,15 @@ static int zynqaes_skcipher_crypt_req(struct crypto_engine *engine,

static int zynqaes_skcipher_crypt(struct skcipher_request *areq, const u32 cmd)
{
struct crypto_skcipher *cipher = crypto_skcipher_reqtfm(areq);
struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
struct zynqaes_skcipher_ctx *ctx = crypto_tfm_ctx(tfm);
struct zynqaes_skcipher_reqctx *rctx = skcipher_request_ctx(areq);
struct zynqaes_dev *dd = zynqaes_find_dev();

if (ctx->need_fallback)
return zynqaes_skcipher_fallback(areq, cmd & ZYNQAES_ENCRYPTION_FLAG);

rctx->base.dd = dd;
rctx->base.cmd = cmd;

Expand All @@ -188,6 +218,19 @@ static int zynqaes_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
{
struct zynqaes_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

ctx->need_fallback = false;

if (len == AES_KEYSIZE_192) {
ctx->need_fallback = true;

crypto_sync_skcipher_clear_flags(ctx->fallback_tfm, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(ctx->fallback_tfm, tfm->base.crt_flags &
CRYPTO_TFM_REQ_MASK);

return crypto_sync_skcipher_setkey(ctx->fallback_tfm, key, len);
}


return zynqaes_setkey(&ctx->base, key, len);
}

Expand Down Expand Up @@ -254,6 +297,15 @@ static int zynqaes_ofb_decrypt(struct skcipher_request *areq)
static int zynqaes_skcipher_init(struct crypto_skcipher *tfm)
{
struct zynqaes_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
const char *name = crypto_tfm_alg_name(&tfm->base);

ctx->fallback_tfm = crypto_alloc_sync_skcipher(name, 0,
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(ctx->fallback_tfm)) {
pr_err("ERROR: Cannot allocate fallback for %s %ld\n",
name, PTR_ERR(ctx->fallback_tfm));
return PTR_ERR(ctx->fallback_tfm);
}

crypto_skcipher_set_reqsize(tfm, sizeof(struct zynqaes_skcipher_reqctx));

Expand All @@ -264,27 +316,37 @@ static int zynqaes_skcipher_init(struct crypto_skcipher *tfm)
return 0;
}

static void zynqaes_skcipher_cra_exit(struct crypto_skcipher *tfm)
{
struct zynqaes_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

crypto_free_sync_skcipher(ctx->fallback_tfm);
}

static struct skcipher_alg zynqaes_skcipher_algs[] = {
{
.base.cra_name = "ecb(aes)",
.base.cra_driver_name = "zynqaes-ecb",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_ASYNC,
.base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct zynqaes_skcipher_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.init = zynqaes_skcipher_init,
.exit = zynqaes_skcipher_cra_exit,
.setkey = zynqaes_skcipher_setkey,
.encrypt = zynqaes_ecb_encrypt,
.decrypt = zynqaes_ecb_decrypt,
}, {
.base.cra_name = "cbc(aes)",
.base.cra_driver_name = "zynqaes-cbc",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_ASYNC,
.base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct zynqaes_skcipher_ctx),
.base.cra_module = THIS_MODULE,
Expand All @@ -293,14 +355,16 @@ static struct skcipher_alg zynqaes_skcipher_algs[] = {
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.init = zynqaes_skcipher_init,
.exit = zynqaes_skcipher_cra_exit,
.setkey = zynqaes_skcipher_setkey,
.encrypt = zynqaes_cbc_encrypt,
.decrypt = zynqaes_cbc_decrypt,
}, {
.base.cra_name = "pcbc(aes)",
.base.cra_driver_name = "zynqaes-pcbc",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_ASYNC,
.base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct zynqaes_skcipher_ctx),
.base.cra_module = THIS_MODULE,
Expand All @@ -309,14 +373,16 @@ static struct skcipher_alg zynqaes_skcipher_algs[] = {
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.init = zynqaes_skcipher_init,
.exit = zynqaes_skcipher_cra_exit,
.setkey = zynqaes_skcipher_setkey,
.encrypt = zynqaes_pcbc_encrypt,
.decrypt = zynqaes_pcbc_decrypt,
}, {
.base.cra_name = "ctr(aes)",
.base.cra_driver_name = "zynqaes-ctr",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_ASYNC,
.base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct zynqaes_skcipher_ctx),
.base.cra_module = THIS_MODULE,
Expand All @@ -325,14 +391,16 @@ static struct skcipher_alg zynqaes_skcipher_algs[] = {
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.init = zynqaes_skcipher_init,
.exit = zynqaes_skcipher_cra_exit,
.setkey = zynqaes_skcipher_setkey,
.encrypt = zynqaes_ctr_encrypt,
.decrypt = zynqaes_ctr_decrypt,
}, {
.base.cra_name = "cfb(aes)",
.base.cra_driver_name = "zynqaes-cfb",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_ASYNC,
.base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct zynqaes_skcipher_ctx),
.base.cra_module = THIS_MODULE,
Expand All @@ -341,14 +409,16 @@ static struct skcipher_alg zynqaes_skcipher_algs[] = {
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.init = zynqaes_skcipher_init,
.exit = zynqaes_skcipher_cra_exit,
.setkey = zynqaes_skcipher_setkey,
.encrypt = zynqaes_cfb_encrypt,
.decrypt = zynqaes_cfb_decrypt,
}, {
.base.cra_name = "ofb(aes)",
.base.cra_driver_name = "zynqaes-ofb",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_ASYNC,
.base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct zynqaes_skcipher_ctx),
.base.cra_module = THIS_MODULE,
Expand All @@ -357,6 +427,7 @@ static struct skcipher_alg zynqaes_skcipher_algs[] = {
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.init = zynqaes_skcipher_init,
.exit = zynqaes_skcipher_cra_exit,
.setkey = zynqaes_skcipher_setkey,
.encrypt = zynqaes_ofb_encrypt,
.decrypt = zynqaes_ofb_decrypt,
Expand Down

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