diff options
Diffstat (limited to 'drivers/crypto/virtio/virtio_crypto_algs.c')
| -rw-r--r-- | drivers/crypto/virtio/virtio_crypto_algs.c | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c new file mode 100644 index 000000000..ae645c9d4 --- /dev/null +++ b/drivers/crypto/virtio/virtio_crypto_algs.c @@ -0,0 +1,656 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + /* Algorithms supported by virtio crypto device + * + * Authors: Gonglei <arei.gonglei@huawei.com> + * + * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD. + */ + +#include <linux/scatterlist.h> +#include <crypto/algapi.h> +#include <crypto/internal/skcipher.h> +#include <linux/err.h> +#include <crypto/scatterwalk.h> +#include <linux/atomic.h> + +#include <uapi/linux/virtio_crypto.h> +#include "virtio_crypto_common.h" + + +struct virtio_crypto_skcipher_ctx { + struct crypto_engine_ctx enginectx; + struct virtio_crypto *vcrypto; + struct crypto_skcipher *tfm; + + struct virtio_crypto_sym_session_info enc_sess_info; + struct virtio_crypto_sym_session_info dec_sess_info; +}; + +struct virtio_crypto_sym_request { + struct virtio_crypto_request base; + + /* Cipher or aead */ + uint32_t type; + struct virtio_crypto_skcipher_ctx *skcipher_ctx; + struct skcipher_request *skcipher_req; + uint8_t *iv; + /* Encryption? */ + bool encrypt; +}; + +struct virtio_crypto_algo { + uint32_t algonum; + uint32_t service; + unsigned int active_devs; + struct skcipher_alg algo; +}; + +/* + * The algs_lock protects the below global virtio_crypto_active_devs + * and crypto algorithms registion. + */ +static DEFINE_MUTEX(algs_lock); +static void virtio_crypto_skcipher_finalize_req( + struct virtio_crypto_sym_request *vc_sym_req, + struct skcipher_request *req, + int err); + +static void virtio_crypto_dataq_sym_callback + (struct virtio_crypto_request *vc_req, int len) +{ + struct virtio_crypto_sym_request *vc_sym_req = + container_of(vc_req, struct virtio_crypto_sym_request, base); + struct skcipher_request *ablk_req; + int error; + + /* Finish the encrypt or decrypt process */ + if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) { + switch (vc_req->status) { + case VIRTIO_CRYPTO_OK: + error = 0; + break; + case VIRTIO_CRYPTO_INVSESS: + case VIRTIO_CRYPTO_ERR: + error = -EINVAL; + break; + case VIRTIO_CRYPTO_BADMSG: + error = -EBADMSG; + break; + default: + error = -EIO; + break; + } + ablk_req = vc_sym_req->skcipher_req; + virtio_crypto_skcipher_finalize_req(vc_sym_req, + ablk_req, error); + } +} + +static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg) +{ + u64 total = 0; + + for (total = 0; sg; sg = sg_next(sg)) + total += sg->length; + + return total; +} + +static int +virtio_crypto_alg_validate_key(int key_len, uint32_t *alg) +{ + switch (key_len) { + case AES_KEYSIZE_128: + case AES_KEYSIZE_192: + case AES_KEYSIZE_256: + *alg = VIRTIO_CRYPTO_CIPHER_AES_CBC; + break; + default: + return -EINVAL; + } + return 0; +} + +static int virtio_crypto_alg_skcipher_init_session( + struct virtio_crypto_skcipher_ctx *ctx, + uint32_t alg, const uint8_t *key, + unsigned int keylen, + int encrypt) +{ + struct scatterlist outhdr, key_sg, inhdr, *sgs[3]; + struct virtio_crypto *vcrypto = ctx->vcrypto; + int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT; + int err; + unsigned int num_out = 0, num_in = 0; + struct virtio_crypto_op_ctrl_req *ctrl; + struct virtio_crypto_session_input *input; + struct virtio_crypto_sym_create_session_req *sym_create_session; + struct virtio_crypto_ctrl_request *vc_ctrl_req; + + /* + * Avoid to do DMA from the stack, switch to using + * dynamically-allocated for the key + */ + uint8_t *cipher_key = kmemdup(key, keylen, GFP_ATOMIC); + + if (!cipher_key) + return -ENOMEM; + + vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL); + if (!vc_ctrl_req) { + err = -ENOMEM; + goto out; + } + + /* Pad ctrl header */ + ctrl = &vc_ctrl_req->ctrl; + ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION); + ctrl->header.algo = cpu_to_le32(alg); + /* Set the default dataqueue id to 0 */ + ctrl->header.queue_id = 0; + + input = &vc_ctrl_req->input; + input->status = cpu_to_le32(VIRTIO_CRYPTO_ERR); + /* Pad cipher's parameters */ + sym_create_session = &ctrl->u.sym_create_session; + sym_create_session->op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER); + sym_create_session->u.cipher.para.algo = ctrl->header.algo; + sym_create_session->u.cipher.para.keylen = cpu_to_le32(keylen); + sym_create_session->u.cipher.para.op = cpu_to_le32(op); + + sg_init_one(&outhdr, ctrl, sizeof(*ctrl)); + sgs[num_out++] = &outhdr; + + /* Set key */ + sg_init_one(&key_sg, cipher_key, keylen); + sgs[num_out++] = &key_sg; + + /* Return status and session id back */ + sg_init_one(&inhdr, input, sizeof(*input)); + sgs[num_out + num_in++] = &inhdr; + + err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req); + if (err < 0) + goto out; + + if (le32_to_cpu(input->status) != VIRTIO_CRYPTO_OK) { + pr_err("virtio_crypto: Create session failed status: %u\n", + le32_to_cpu(input->status)); + err = -EINVAL; + goto out; + } + + if (encrypt) + ctx->enc_sess_info.session_id = le64_to_cpu(input->session_id); + else + ctx->dec_sess_info.session_id = le64_to_cpu(input->session_id); + + err = 0; +out: + kfree(vc_ctrl_req); + kfree_sensitive(cipher_key); + return err; +} + +static int virtio_crypto_alg_skcipher_close_session( + struct virtio_crypto_skcipher_ctx *ctx, + int encrypt) +{ + struct scatterlist outhdr, status_sg, *sgs[2]; + struct virtio_crypto_destroy_session_req *destroy_session; + struct virtio_crypto *vcrypto = ctx->vcrypto; + int err; + unsigned int num_out = 0, num_in = 0; + struct virtio_crypto_op_ctrl_req *ctrl; + struct virtio_crypto_inhdr *ctrl_status; + struct virtio_crypto_ctrl_request *vc_ctrl_req; + + vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL); + if (!vc_ctrl_req) + return -ENOMEM; + + ctrl_status = &vc_ctrl_req->ctrl_status; + ctrl_status->status = VIRTIO_CRYPTO_ERR; + /* Pad ctrl header */ + ctrl = &vc_ctrl_req->ctrl; + ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION); + /* Set the default virtqueue id to 0 */ + ctrl->header.queue_id = 0; + + destroy_session = &ctrl->u.destroy_session; + + if (encrypt) + destroy_session->session_id = cpu_to_le64(ctx->enc_sess_info.session_id); + else + destroy_session->session_id = cpu_to_le64(ctx->dec_sess_info.session_id); + + sg_init_one(&outhdr, ctrl, sizeof(*ctrl)); + sgs[num_out++] = &outhdr; + + /* Return status and session id back */ + sg_init_one(&status_sg, &ctrl_status->status, sizeof(ctrl_status->status)); + sgs[num_out + num_in++] = &status_sg; + + err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req); + if (err < 0) + goto out; + + if (ctrl_status->status != VIRTIO_CRYPTO_OK) { + pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n", + ctrl_status->status, destroy_session->session_id); + + err = -EINVAL; + goto out; + } + + err = 0; +out: + kfree(vc_ctrl_req); + return err; +} + +static int virtio_crypto_alg_skcipher_init_sessions( + struct virtio_crypto_skcipher_ctx *ctx, + const uint8_t *key, unsigned int keylen) +{ + uint32_t alg; + int ret; + struct virtio_crypto *vcrypto = ctx->vcrypto; + + if (keylen > vcrypto->max_cipher_key_len) { + pr_err("virtio_crypto: the key is too long\n"); + return -EINVAL; + } + + if (virtio_crypto_alg_validate_key(keylen, &alg)) + return -EINVAL; + + /* Create encryption session */ + ret = virtio_crypto_alg_skcipher_init_session(ctx, + alg, key, keylen, 1); + if (ret) + return ret; + /* Create decryption session */ + ret = virtio_crypto_alg_skcipher_init_session(ctx, + alg, key, keylen, 0); + if (ret) { + virtio_crypto_alg_skcipher_close_session(ctx, 1); + return ret; + } + return 0; +} + +/* Note: kernel crypto API realization */ +static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm, + const uint8_t *key, + unsigned int keylen) +{ + struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm); + uint32_t alg; + int ret; + + ret = virtio_crypto_alg_validate_key(keylen, &alg); + if (ret) + return ret; + + if (!ctx->vcrypto) { + /* New key */ + int node = virtio_crypto_get_current_node(); + struct virtio_crypto *vcrypto = + virtcrypto_get_dev_node(node, + VIRTIO_CRYPTO_SERVICE_CIPHER, alg); + if (!vcrypto) { + pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n"); + return -ENODEV; + } + + ctx->vcrypto = vcrypto; + } else { + /* Rekeying, we should close the created sessions previously */ + virtio_crypto_alg_skcipher_close_session(ctx, 1); + virtio_crypto_alg_skcipher_close_session(ctx, 0); + } + + ret = virtio_crypto_alg_skcipher_init_sessions(ctx, key, keylen); + if (ret) { + virtcrypto_dev_put(ctx->vcrypto); + ctx->vcrypto = NULL; + + return ret; + } + + return 0; +} + +static int +__virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req, + struct skcipher_request *req, + struct data_queue *data_vq) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct virtio_crypto_skcipher_ctx *ctx = vc_sym_req->skcipher_ctx; + struct virtio_crypto_request *vc_req = &vc_sym_req->base; + unsigned int ivsize = crypto_skcipher_ivsize(tfm); + struct virtio_crypto *vcrypto = ctx->vcrypto; + struct virtio_crypto_op_data_req *req_data; + int src_nents, dst_nents; + int err; + unsigned long flags; + struct scatterlist outhdr, iv_sg, status_sg, **sgs; + u64 dst_len; + unsigned int num_out = 0, num_in = 0; + int sg_total; + uint8_t *iv; + struct scatterlist *sg; + + src_nents = sg_nents_for_len(req->src, req->cryptlen); + if (src_nents < 0) { + pr_err("Invalid number of src SG.\n"); + return src_nents; + } + + dst_nents = sg_nents(req->dst); + + pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n", + src_nents, dst_nents); + + /* Why 3? outhdr + iv + inhdr */ + sg_total = src_nents + dst_nents + 3; + sgs = kcalloc_node(sg_total, sizeof(*sgs), GFP_KERNEL, + dev_to_node(&vcrypto->vdev->dev)); + if (!sgs) + return -ENOMEM; + + req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL, + dev_to_node(&vcrypto->vdev->dev)); + if (!req_data) { + kfree(sgs); + return -ENOMEM; + } + + vc_req->req_data = req_data; + vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER; + /* Head of operation */ + if (vc_sym_req->encrypt) { + req_data->header.session_id = + cpu_to_le64(ctx->enc_sess_info.session_id); + req_data->header.opcode = + cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT); + } else { + req_data->header.session_id = + cpu_to_le64(ctx->dec_sess_info.session_id); + req_data->header.opcode = + cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT); + } + req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER); + req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize); + req_data->u.sym_req.u.cipher.para.src_data_len = + cpu_to_le32(req->cryptlen); + + dst_len = virtio_crypto_alg_sg_nents_length(req->dst); + if (unlikely(dst_len > U32_MAX)) { + pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n"); + err = -EINVAL; + goto free; + } + + dst_len = min_t(unsigned int, req->cryptlen, dst_len); + pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n", + req->cryptlen, dst_len); + + if (unlikely(req->cryptlen + dst_len + ivsize + + sizeof(vc_req->status) > vcrypto->max_size)) { + pr_err("virtio_crypto: The length is too big\n"); + err = -EINVAL; + goto free; + } + + req_data->u.sym_req.u.cipher.para.dst_data_len = + cpu_to_le32((uint32_t)dst_len); + + /* Outhdr */ + sg_init_one(&outhdr, req_data, sizeof(*req_data)); + sgs[num_out++] = &outhdr; + + /* IV */ + + /* + * Avoid to do DMA from the stack, switch to using + * dynamically-allocated for the IV + */ + iv = kzalloc_node(ivsize, GFP_ATOMIC, + dev_to_node(&vcrypto->vdev->dev)); + if (!iv) { + err = -ENOMEM; + goto free; + } + memcpy(iv, req->iv, ivsize); + if (!vc_sym_req->encrypt) + scatterwalk_map_and_copy(req->iv, req->src, + req->cryptlen - AES_BLOCK_SIZE, + AES_BLOCK_SIZE, 0); + + sg_init_one(&iv_sg, iv, ivsize); + sgs[num_out++] = &iv_sg; + vc_sym_req->iv = iv; + + /* Source data */ + for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--) + sgs[num_out++] = sg; + + /* Destination data */ + for (sg = req->dst; sg; sg = sg_next(sg)) + sgs[num_out + num_in++] = sg; + + /* Status */ + sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status)); + sgs[num_out + num_in++] = &status_sg; + + vc_req->sgs = sgs; + + spin_lock_irqsave(&data_vq->lock, flags); + err = virtqueue_add_sgs(data_vq->vq, sgs, num_out, + num_in, vc_req, GFP_ATOMIC); + virtqueue_kick(data_vq->vq); + spin_unlock_irqrestore(&data_vq->lock, flags); + if (unlikely(err < 0)) + goto free_iv; + + return 0; + +free_iv: + kfree_sensitive(iv); +free: + kfree_sensitive(req_data); + kfree(sgs); + return err; +} + +static int virtio_crypto_skcipher_encrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req); + struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm); + struct virtio_crypto_sym_request *vc_sym_req = + skcipher_request_ctx(req); + struct virtio_crypto_request *vc_req = &vc_sym_req->base; + struct virtio_crypto *vcrypto = ctx->vcrypto; + /* Use the first data virtqueue as default */ + struct data_queue *data_vq = &vcrypto->data_vq[0]; + + if (!req->cryptlen) + return 0; + if (req->cryptlen % AES_BLOCK_SIZE) + return -EINVAL; + + vc_req->dataq = data_vq; + vc_req->alg_cb = virtio_crypto_dataq_sym_callback; + vc_sym_req->skcipher_ctx = ctx; + vc_sym_req->skcipher_req = req; + vc_sym_req->encrypt = true; + + return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req); +} + +static int virtio_crypto_skcipher_decrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req); + struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm); + struct virtio_crypto_sym_request *vc_sym_req = + skcipher_request_ctx(req); + struct virtio_crypto_request *vc_req = &vc_sym_req->base; + struct virtio_crypto *vcrypto = ctx->vcrypto; + /* Use the first data virtqueue as default */ + struct data_queue *data_vq = &vcrypto->data_vq[0]; + + if (!req->cryptlen) + return 0; + if (req->cryptlen % AES_BLOCK_SIZE) + return -EINVAL; + + vc_req->dataq = data_vq; + vc_req->alg_cb = virtio_crypto_dataq_sym_callback; + vc_sym_req->skcipher_ctx = ctx; + vc_sym_req->skcipher_req = req; + vc_sym_req->encrypt = false; + + return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req); +} + +static int virtio_crypto_skcipher_init(struct crypto_skcipher *tfm) +{ + struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm); + + crypto_skcipher_set_reqsize(tfm, sizeof(struct virtio_crypto_sym_request)); + ctx->tfm = tfm; + + ctx->enginectx.op.do_one_request = virtio_crypto_skcipher_crypt_req; + ctx->enginectx.op.prepare_request = NULL; + ctx->enginectx.op.unprepare_request = NULL; + return 0; +} + +static void virtio_crypto_skcipher_exit(struct crypto_skcipher *tfm) +{ + struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm); + + if (!ctx->vcrypto) + return; + + virtio_crypto_alg_skcipher_close_session(ctx, 1); + virtio_crypto_alg_skcipher_close_session(ctx, 0); + virtcrypto_dev_put(ctx->vcrypto); + ctx->vcrypto = NULL; +} + +int virtio_crypto_skcipher_crypt_req( + struct crypto_engine *engine, void *vreq) +{ + struct skcipher_request *req = container_of(vreq, struct skcipher_request, base); + struct virtio_crypto_sym_request *vc_sym_req = + skcipher_request_ctx(req); + struct virtio_crypto_request *vc_req = &vc_sym_req->base; + struct data_queue *data_vq = vc_req->dataq; + int ret; + + ret = __virtio_crypto_skcipher_do_req(vc_sym_req, req, data_vq); + if (ret < 0) + return ret; + + virtqueue_kick(data_vq->vq); + + return 0; +} + +static void virtio_crypto_skcipher_finalize_req( + struct virtio_crypto_sym_request *vc_sym_req, + struct skcipher_request *req, + int err) +{ + if (vc_sym_req->encrypt) + scatterwalk_map_and_copy(req->iv, req->dst, + req->cryptlen - AES_BLOCK_SIZE, + AES_BLOCK_SIZE, 0); + kfree_sensitive(vc_sym_req->iv); + virtcrypto_clear_request(&vc_sym_req->base); + + crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine, + req, err); +} + +static struct virtio_crypto_algo virtio_crypto_algs[] = { { + .algonum = VIRTIO_CRYPTO_CIPHER_AES_CBC, + .service = VIRTIO_CRYPTO_SERVICE_CIPHER, + .algo = { + .base.cra_name = "cbc(aes)", + .base.cra_driver_name = "virtio_crypto_aes_cbc", + .base.cra_priority = 150, + .base.cra_flags = CRYPTO_ALG_ASYNC | + CRYPTO_ALG_ALLOCATES_MEMORY, + .base.cra_blocksize = AES_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct virtio_crypto_skcipher_ctx), + .base.cra_module = THIS_MODULE, + .init = virtio_crypto_skcipher_init, + .exit = virtio_crypto_skcipher_exit, + .setkey = virtio_crypto_skcipher_setkey, + .decrypt = virtio_crypto_skcipher_decrypt, + .encrypt = virtio_crypto_skcipher_encrypt, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + }, +} }; + +int virtio_crypto_algs_register(struct virtio_crypto *vcrypto) +{ + int ret = 0; + int i = 0; + + mutex_lock(&algs_lock); + + for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) { + + uint32_t service = virtio_crypto_algs[i].service; + uint32_t algonum = virtio_crypto_algs[i].algonum; + + if (!virtcrypto_algo_is_supported(vcrypto, service, algonum)) + continue; + + if (virtio_crypto_algs[i].active_devs == 0) { + ret = crypto_register_skcipher(&virtio_crypto_algs[i].algo); + if (ret) + goto unlock; + } + + virtio_crypto_algs[i].active_devs++; + dev_info(&vcrypto->vdev->dev, "Registered algo %s\n", + virtio_crypto_algs[i].algo.base.cra_name); + } + +unlock: + mutex_unlock(&algs_lock); + return ret; +} + +void virtio_crypto_algs_unregister(struct virtio_crypto *vcrypto) +{ + int i = 0; + + mutex_lock(&algs_lock); + + for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) { + + uint32_t service = virtio_crypto_algs[i].service; + uint32_t algonum = virtio_crypto_algs[i].algonum; + + if (virtio_crypto_algs[i].active_devs == 0 || + !virtcrypto_algo_is_supported(vcrypto, service, algonum)) + continue; + + if (virtio_crypto_algs[i].active_devs == 1) + crypto_unregister_skcipher(&virtio_crypto_algs[i].algo); + + virtio_crypto_algs[i].active_devs--; + } + + mutex_unlock(&algs_lock); +} |