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path: root/drivers/crypto/omap-aes-gcm.c
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Diffstat (limited to 'drivers/crypto/omap-aes-gcm.c')
-rw-r--r--drivers/crypto/omap-aes-gcm.c408
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;
+}