static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int nbytes = req->cryptlen - (enc ? 0 : authsize);
struct blkcipher_desc desc = {
.tfm = ctx->null,
};
return crypto_blkcipher_encrypt(&desc, req->dst, req->src, nbytes);
}
static int crypto_rfc4543_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
struct aead_request *subreq;
int err;
if (req->src != req->dst) {
err = crypto_rfc4543_copy_src_to_dst(req, true);
if (err)
return err;
}
subreq = crypto_rfc4543_crypt(req, true);
err = crypto_aead_encrypt(subreq);
if (err)
return err;
scatterwalk_map_and_copy(rctx->auth_tag, req->dst, req->cryptlen,
crypto_aead_authsize(aead), 1);
return 0;
}
static int crypto_rfc4543_decrypt(struct aead_request *req)
{
int err;
if (req->src != req->dst) {
err = crypto_rfc4543_copy_src_to_dst(req, false);
if (err)
return err;
}
req = crypto_rfc4543_crypt(req, false);
return crypto_aead_decrypt(req);
}
static int crypto_rfc4543_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
struct aead_request *subreq;
int err;
subreq = crypto_rfc4543_crypt(req, 1);
err = crypto_aead_encrypt(subreq);
if (err)
return err;
scatterwalk_map_and_copy(rctx->auth_tag, req->dst, req->cryptlen,
crypto_aead_authsize(aead), 1);
return 0;
}
static int crypto_rfc4543_decrypt(struct aead_request *req)
{
req = crypto_rfc4543_crypt(req, 0);
return crypto_aead_decrypt(req);
}
