static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
unsigned int cryptlen)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct crypto_cipher *cipher = ctx->cipher;
unsigned int assoclen = req->assoclen;
u8 *odata = pctx->odata;
u8 *idata = pctx->idata;
int err;
/* format control data for input */
err = format_input(odata, req, cryptlen);
if (err)
goto out;
/* encrypt first block to use as start in computing mac */
crypto_cipher_encrypt_one(cipher, odata, odata);
/* format associated data and compute into mac */
if (assoclen) {
pctx->ilen = format_adata(idata, assoclen);
get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
} else {
pctx->ilen = 0;
}
/* compute plaintext into mac */
if (cryptlen)
get_data_to_compute(cipher, pctx, plain, cryptlen);
out:
return err;
}
static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
{
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct scatterlist *sg;
u8 *iv = req->iv;
int err;
err = crypto_ccm_check_iv(iv);
if (err)
return err;
pctx->flags = aead_request_flags(req);
/* Note: rfc 3610 and NIST 800-38C require counter of
* zero to encrypt auth tag.
*/
memset(iv + 15 - iv[0], 0, iv[0] + 1);
sg_init_table(pctx->src, 3);
sg_set_buf(pctx->src, tag, 16);
sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
if (sg != pctx->src + 1)
sg_chain(pctx->src, 2, sg);
if (req->src != req->dst) {
sg_init_table(pctx->dst, 3);
sg_set_buf(pctx->dst, tag, 16);
sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
if (sg != pctx->dst + 1)
sg_chain(pctx->dst, 2, sg);
}
return 0;
}
static int crypto_ccm_decrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct ablkcipher_request *abreq = &pctx->abreq;
struct scatterlist *dst;
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen;
u8 *authtag = pctx->auth_tag;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;
if (cryptlen < authsize)
return -EINVAL;
cryptlen -= authsize;
err = crypto_ccm_check_iv(iv);
if (err)
return err;
pctx->flags = aead_request_flags(req);
scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
memset(iv + 15 - iv[0], 0, iv[0] + 1);
sg_init_table(pctx->src, 2);
sg_set_buf(pctx->src, authtag, 16);
scatterwalk_sg_chain(pctx->src, 2, req->src);
dst = pctx->src;
if (req->src != req->dst) {
sg_init_table(pctx->dst, 2);
sg_set_buf(pctx->dst, authtag, 16);
scatterwalk_sg_chain(pctx->dst, 2, req->dst);
dst = pctx->dst;
}
ablkcipher_request_set_tfm(abreq, ctx->ctr);
ablkcipher_request_set_callback(abreq, pctx->flags,
crypto_ccm_decrypt_done, req);
ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_ablkcipher_decrypt(abreq);
if (err)
return err;
err = crypto_ccm_auth(req, req->dst, cryptlen);
if (err)
return err;
/* verify */
if (crypto_memneq(authtag, odata, authsize))
return -EBADMSG;
return err;
}
static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
u8 *odata = pctx->odata;
if (!err)
scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
crypto_aead_authsize(aead), 1);
aead_request_complete(req, err);
}
static int crypto_ccm_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct ablkcipher_request *abreq = &pctx->abreq;
struct scatterlist *dst;
unsigned int cryptlen = req->cryptlen;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;
err = crypto_ccm_check_iv(iv);
if (err)
return err;
pctx->flags = aead_request_flags(req);
err = crypto_ccm_auth(req, req->src, cryptlen);
if (err)
return err;
/* Note: rfc 3610 and NIST 800-38C require counter of
* zero to encrypt auth tag.
*/
memset(iv + 15 - iv[0], 0, iv[0] + 1);
sg_init_table(pctx->src, 2);
sg_set_buf(pctx->src, odata, 16);
scatterwalk_sg_chain(pctx->src, 2, req->src);
dst = pctx->src;
if (req->src != req->dst) {
sg_init_table(pctx->dst, 2);
sg_set_buf(pctx->dst, odata, 16);
scatterwalk_sg_chain(pctx->dst, 2, req->dst);
dst = pctx->dst;
}
ablkcipher_request_set_tfm(abreq, ctx->ctr);
ablkcipher_request_set_callback(abreq, pctx->flags,
crypto_ccm_encrypt_done, req);
ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_ablkcipher_encrypt(abreq);
if (err)
return err;
/* copy authtag to end of dst */
scatterwalk_map_and_copy(odata, req->dst, cryptlen,
crypto_aead_authsize(aead), 1);
return err;
}
static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct crypto_aead *aead = crypto_aead_reqtfm(req);
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen - authsize;
if (!err) {
err = crypto_ccm_auth(req, req->dst, cryptlen);
if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
err = -EBADMSG;
}
aead_request_complete(req, err);
}
static int crypto_ccm_decrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct ablkcipher_request *abreq = &pctx->abreq;
struct scatterlist *dst;
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen;
u8 *authtag = pctx->auth_tag;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;
cryptlen -= authsize;
err = crypto_ccm_init_crypt(req, authtag);
if (err)
return err;
scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
authsize, 0);
dst = pctx->src;
if (req->src != req->dst)
dst = pctx->dst;
ablkcipher_request_set_tfm(abreq, ctx->ctr);
ablkcipher_request_set_callback(abreq, pctx->flags,
crypto_ccm_decrypt_done, req);
ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_ablkcipher_decrypt(abreq);
if (err)
return err;
err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
if (err)
return err;
/* verify */
if (crypto_memneq(authtag, odata, authsize))
return -EBADMSG;
return err;
}
static int crypto_ccm_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct ablkcipher_request *abreq = &pctx->abreq;
struct scatterlist *dst;
unsigned int cryptlen = req->cryptlen;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;
err = crypto_ccm_init_crypt(req, odata);
if (err)
return err;
err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
if (err)
return err;
dst = pctx->src;
if (req->src != req->dst)
dst = pctx->dst;
ablkcipher_request_set_tfm(abreq, ctx->ctr);
ablkcipher_request_set_callback(abreq, pctx->flags,
crypto_ccm_encrypt_done, req);
ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_ablkcipher_encrypt(abreq);
if (err)
return err;
/* copy authtag to end of dst */
scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
crypto_aead_authsize(aead), 1);
return err;
}
