diff options
Diffstat (limited to 'drivers/crypto/omap-aes-gcm.c')
| -rw-r--r-- | drivers/crypto/omap-aes-gcm.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/drivers/crypto/omap-aes-gcm.c b/drivers/crypto/omap-aes-gcm.c new file mode 100644 index 000000000000..7d4f8a4be6d8 --- /dev/null +++ b/drivers/crypto/omap-aes-gcm.c @@ -0,0 +1,408 @@ +/* + * Cryptographic API. + * + * Support for OMAP AES GCM HW acceleration. + * + * Copyright (c) 2016 Texas Instruments Incorporated + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + */ + +#include <linux/errno.h> +#include <linux/scatterlist.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/omap-dma.h> +#include <linux/interrupt.h> +#include <crypto/aes.h> +#include <crypto/scatterwalk.h> +#include <crypto/skcipher.h> +#include <crypto/internal/aead.h> + +#include "omap-crypto.h" +#include "omap-aes.h" + +static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd, + struct aead_request *req); + +static void omap_aes_gcm_finish_req(struct omap_aes_dev *dd, int ret) +{ + struct aead_request *req = dd->aead_req; + + dd->flags &= ~FLAGS_BUSY; + dd->in_sg = NULL; + dd->out_sg = NULL; + + req->base.complete(&req->base, ret); +} + +static void omap_aes_gcm_done_task(struct omap_aes_dev *dd) +{ + u8 *tag; + int alen, clen, i, ret = 0, nsg; + struct omap_aes_reqctx *rctx; + + alen = ALIGN(dd->assoc_len, AES_BLOCK_SIZE); + clen = ALIGN(dd->total, AES_BLOCK_SIZE); + rctx = aead_request_ctx(dd->aead_req); + + nsg = !!(dd->assoc_len && dd->total); + + dma_sync_sg_for_device(dd->dev, dd->out_sg, dd->out_sg_len, + DMA_FROM_DEVICE); + dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE); + dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len, DMA_FROM_DEVICE); + omap_aes_crypt_dma_stop(dd); + + omap_crypto_cleanup(dd->out_sg, dd->orig_out, + dd->aead_req->assoclen, dd->total, + FLAGS_OUT_DATA_ST_SHIFT, dd->flags); + + if (dd->flags & FLAGS_ENCRYPT) + scatterwalk_map_and_copy(rctx->auth_tag, + dd->aead_req->dst, + dd->total + dd->aead_req->assoclen, + dd->authsize, 1); + + omap_crypto_cleanup(&dd->in_sgl[0], NULL, 0, alen, + FLAGS_ASSOC_DATA_ST_SHIFT, dd->flags); + + omap_crypto_cleanup(&dd->in_sgl[nsg], NULL, 0, clen, + FLAGS_IN_DATA_ST_SHIFT, dd->flags); + + if (!(dd->flags & FLAGS_ENCRYPT)) { + tag = (u8 *)rctx->auth_tag; + for (i = 0; i < dd->authsize; i++) { + if (tag[i]) { + dev_err(dd->dev, "GCM decryption: Tag Message is wrong\n"); + ret = -EBADMSG; + } + } + } + + omap_aes_gcm_finish_req(dd, ret); + omap_aes_gcm_handle_queue(dd, NULL); +} + +static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd, + struct aead_request *req) +{ + int alen, clen, cryptlen, assoclen, ret; + struct crypto_aead *aead = crypto_aead_reqtfm(req); + unsigned int authlen = crypto_aead_authsize(aead); + struct scatterlist *tmp, sg_arr[2]; + int nsg; + u16 flags; + + assoclen = req->assoclen; + cryptlen = req->cryptlen; + + if (dd->flags & FLAGS_RFC4106_GCM) + assoclen -= 8; + + if (!(dd->flags & FLAGS_ENCRYPT)) + cryptlen -= authlen; + + alen = ALIGN(assoclen, AES_BLOCK_SIZE); + clen = ALIGN(cryptlen, AES_BLOCK_SIZE); + + nsg = !!(assoclen && cryptlen); + + omap_aes_clear_copy_flags(dd); + + sg_init_table(dd->in_sgl, nsg + 1); + if (assoclen) { + tmp = req->src; + ret = omap_crypto_align_sg(&tmp, assoclen, + AES_BLOCK_SIZE, dd->in_sgl, + OMAP_CRYPTO_COPY_DATA | + OMAP_CRYPTO_ZERO_BUF | + OMAP_CRYPTO_FORCE_SINGLE_ENTRY, + FLAGS_ASSOC_DATA_ST_SHIFT, + &dd->flags); + } + + if (cryptlen) { + tmp = scatterwalk_ffwd(sg_arr, req->src, req->assoclen); + + ret = omap_crypto_align_sg(&tmp, cryptlen, + AES_BLOCK_SIZE, &dd->in_sgl[nsg], + OMAP_CRYPTO_COPY_DATA | + OMAP_CRYPTO_ZERO_BUF | + OMAP_CRYPTO_FORCE_SINGLE_ENTRY, + FLAGS_IN_DATA_ST_SHIFT, + &dd->flags); + } + + dd->in_sg = dd->in_sgl; + dd->total = cryptlen; + dd->assoc_len = assoclen; + dd->authsize = authlen; + + dd->out_sg = req->dst; + dd->orig_out = req->dst; + + dd->out_sg = scatterwalk_ffwd(sg_arr, req->dst, assoclen); + + flags = 0; + if (req->src == req->dst || dd->out_sg == sg_arr) + flags |= OMAP_CRYPTO_FORCE_COPY; + + ret = omap_crypto_align_sg(&dd->out_sg, cryptlen, + AES_BLOCK_SIZE, &dd->out_sgl, + flags, + FLAGS_OUT_DATA_ST_SHIFT, &dd->flags); + if (ret) + return ret; + + dd->in_sg_len = sg_nents_for_len(dd->in_sg, alen + clen); + dd->out_sg_len = sg_nents_for_len(dd->out_sg, clen); + + return 0; +} + +static void omap_aes_gcm_complete(struct crypto_async_request *req, int err) +{ + struct omap_aes_gcm_result *res = req->data; + + if (err == -EINPROGRESS) + return; + + res->err = err; + complete(&res->completion); +} + +static int do_encrypt_iv(struct aead_request *req, u32 *tag, u32 *iv) +{ + struct scatterlist iv_sg, tag_sg; + struct skcipher_request *sk_req; + struct omap_aes_gcm_result result; + struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + int ret = 0; + + sk_req = skcipher_request_alloc(ctx->ctr, GFP_KERNEL); + if (!sk_req) { + pr_err("skcipher: Failed to allocate request\n"); + return -1; + } + + init_completion(&result.completion); + + sg_init_one(&iv_sg, iv, AES_BLOCK_SIZE); + sg_init_one(&tag_sg, tag, AES_BLOCK_SIZE); + skcipher_request_set_callback(sk_req, CRYPTO_TFM_REQ_MAY_BACKLOG, + omap_aes_gcm_complete, &result); + ret = crypto_skcipher_setkey(ctx->ctr, (u8 *)ctx->key, ctx->keylen); + skcipher_request_set_crypt(sk_req, &iv_sg, &tag_sg, AES_BLOCK_SIZE, + NULL); + ret = crypto_skcipher_encrypt(sk_req); + switch (ret) { + case 0: + break; + case -EINPROGRESS: + case -EBUSY: + ret = wait_for_completion_interruptible(&result.completion); + if (!ret) { + ret = result.err; + if (!ret) { + reinit_completion(&result.completion); + break; + } + } + /* fall through */ + default: + pr_err("Encryption of IV failed for GCM mode"); + break; + } + + skcipher_request_free(sk_req); + return ret; +} + +void omap_aes_gcm_dma_out_callback(void *data) +{ + struct omap_aes_dev *dd = data; + struct omap_aes_reqctx *rctx; + int i, val; + u32 *auth_tag, tag[4]; + + if (!(dd->flags & FLAGS_ENCRYPT)) + scatterwalk_map_and_copy(tag, dd->aead_req->src, + dd->total + dd->aead_req->assoclen, + dd->authsize, 0); + + rctx = aead_request_ctx(dd->aead_req); + auth_tag = (u32 *)rctx->auth_tag; + for (i = 0; i < 4; i++) { + val = omap_aes_read(dd, AES_REG_TAG_N(dd, i)); + auth_tag[i] = val ^ auth_tag[i]; + if (!(dd->flags & FLAGS_ENCRYPT)) + auth_tag[i] = auth_tag[i] ^ tag[i]; + } + + omap_aes_gcm_done_task(dd); +} + +static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd, + struct aead_request *req) +{ + struct omap_aes_ctx *ctx; + struct aead_request *backlog; + struct omap_aes_reqctx *rctx; + unsigned long flags; + int err, ret = 0; + + spin_lock_irqsave(&dd->lock, flags); + if (req) + ret = aead_enqueue_request(&dd->aead_queue, req); + if (dd->flags & FLAGS_BUSY) { + spin_unlock_irqrestore(&dd->lock, flags); + return ret; + } + + backlog = aead_get_backlog(&dd->aead_queue); + req = aead_dequeue_request(&dd->aead_queue); + if (req) + dd->flags |= FLAGS_BUSY; + spin_unlock_irqrestore(&dd->lock, flags); + + if (!req) + return ret; + + if (backlog) + backlog->base.complete(&backlog->base, -EINPROGRESS); + + ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + rctx = aead_request_ctx(req); + + dd->ctx = ctx; + rctx->dd = dd; + dd->aead_req = req; + + rctx->mode &= FLAGS_MODE_MASK; + dd->flags = (dd->flags & ~FLAGS_MODE_MASK) | rctx->mode; + + err = omap_aes_gcm_copy_buffers(dd, req); + if (err) + return err; + + err = omap_aes_write_ctrl(dd); + if (!err) + err = omap_aes_crypt_dma_start(dd); + + if (err) { + omap_aes_gcm_finish_req(dd, err); + omap_aes_gcm_handle_queue(dd, NULL); + } + + return ret; +} + +static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode) +{ + struct omap_aes_reqctx *rctx = aead_request_ctx(req); + struct crypto_aead *aead = crypto_aead_reqtfm(req); + unsigned int authlen = crypto_aead_authsize(aead); + struct omap_aes_dev *dd; + __be32 counter = cpu_to_be32(1); + int err, assoclen; + + memset(rctx->auth_tag, 0, sizeof(rctx->auth_tag)); + memcpy(rctx->iv + 12, &counter, 4); + + err = do_encrypt_iv(req, (u32 *)rctx->auth_tag, (u32 *)rctx->iv); + if (err) + return err; + + if (mode & FLAGS_RFC4106_GCM) + assoclen = req->assoclen - 8; + else + assoclen = req->assoclen; + if (assoclen + req->cryptlen == 0) { + scatterwalk_map_and_copy(rctx->auth_tag, req->dst, 0, authlen, + 1); + return 0; + } + + dd = omap_aes_find_dev(rctx); + if (!dd) + return -ENODEV; + rctx->mode = mode; + + return omap_aes_gcm_handle_queue(dd, req); +} + +int omap_aes_gcm_encrypt(struct aead_request *req) +{ + struct omap_aes_reqctx *rctx = aead_request_ctx(req); + + memcpy(rctx->iv, req->iv, 12); + return omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM); +} + +int omap_aes_gcm_decrypt(struct aead_request *req) +{ + struct omap_aes_reqctx *rctx = aead_request_ctx(req); + + memcpy(rctx->iv, req->iv, 12); + return omap_aes_gcm_crypt(req, FLAGS_GCM); +} + +int omap_aes_4106gcm_encrypt(struct aead_request *req) +{ + struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct omap_aes_reqctx *rctx = aead_request_ctx(req); + + memcpy(rctx->iv, ctx->nonce, 4); + memcpy(rctx->iv + 4, req->iv, 8); + return omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM | + FLAGS_RFC4106_GCM); +} + +int omap_aes_4106gcm_decrypt(struct aead_request *req) +{ + struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); + struct omap_aes_reqctx *rctx = aead_request_ctx(req); + + memcpy(rctx->iv, ctx->nonce, 4); + memcpy(rctx->iv + 4, req->iv, 8); + return omap_aes_gcm_crypt(req, FLAGS_GCM | FLAGS_RFC4106_GCM); +} + +int omap_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key, + unsigned int keylen) +{ + struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm); + + if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 && + keylen != AES_KEYSIZE_256) + return -EINVAL; + + memcpy(ctx->key, key, keylen); + ctx->keylen = keylen; + + return 0; +} + +int omap_aes_4106gcm_setkey(struct crypto_aead *tfm, const u8 *key, + unsigned int keylen) +{ + struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm); + + if (keylen < 4) + return -EINVAL; + + keylen -= 4; + if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 && + keylen != AES_KEYSIZE_256) + return -EINVAL; + + memcpy(ctx->key, key, keylen); + memcpy(ctx->nonce, key + keylen, 4); + ctx->keylen = keylen; + + return 0; +} |