diff options
author | Gilad Ben-Yossef <gilad@benyossef.com> | 2017-08-23 12:12:05 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-24 02:22:35 +0300 |
commit | 737aed947f9b5bd749a2684e13572ee99a1b8bae (patch) | |
tree | 9fb6077db2855a747d918a382c541e8c6652554b /drivers/staging/ccree | |
parent | 19dfd8810716060a7075fe420ea4e98d7d65be86 (diff) | |
download | linux-737aed947f9b5bd749a2684e13572ee99a1b8bae.tar.xz |
staging: ccree: save ciphertext for CTS IV
The crypto API requires saving the last blocks of ciphertext
in req->info for use as IV for CTS mode. The ccree driver
was not doing this. This patch fixes that.
The bug was manifested with cts(cbc(aes)) mode in tcrypt tests.
Fixes: 302ef8ebb4b2 ("Add CryptoCell skcipher support")
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/ccree')
-rw-r--r-- | drivers/staging/ccree/ssi_cipher.c | 40 |
1 files changed, 36 insertions, 4 deletions
diff --git a/drivers/staging/ccree/ssi_cipher.c b/drivers/staging/ccree/ssi_cipher.c index af9afead7bcb..8d31a93fd8b7 100644 --- a/drivers/staging/ccree/ssi_cipher.c +++ b/drivers/staging/ccree/ssi_cipher.c @@ -24,6 +24,7 @@ #include <crypto/ctr.h> #include <crypto/des.h> #include <crypto/xts.h> +#include <crypto/scatterwalk.h> #include "ssi_config.h" #include "ssi_driver.h" @@ -697,6 +698,7 @@ static int ssi_blkcipher_complete(struct device *dev, { int completion_error = 0; u32 inflight_counter; + struct ablkcipher_request *req = (struct ablkcipher_request *)areq; ssi_buffer_mgr_unmap_blkcipher_request(dev, req_ctx, ivsize, src, dst); @@ -707,6 +709,22 @@ static int ssi_blkcipher_complete(struct device *dev, ctx_p->drvdata->inflight_counter--; if (areq) { + /* + * The crypto API expects us to set the req->info to the last + * ciphertext block. For encrypt, simply copy from the result. + * For decrypt, we must copy from a saved buffer since this + * could be an in-place decryption operation and the src is + * lost by this point. + */ + if (req_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_DECRYPT) { + memcpy(req->info, req_ctx->backup_info, ivsize); + kfree(req_ctx->backup_info); + } else { + scatterwalk_map_and_copy(req->info, req->dst, + (req->nbytes - ivsize), + ivsize, 0); + } + ablkcipher_request_complete(areq, completion_error); return 0; } @@ -739,11 +757,13 @@ static int ssi_blkcipher_process( if (unlikely(validate_data_size(ctx_p, nbytes))) { SSI_LOG_ERR("Unsupported data size %d.\n", nbytes); crypto_tfm_set_flags(tfm, CRYPTO_TFM_RES_BAD_BLOCK_LEN); - return -EINVAL; + rc = -EINVAL; + goto exit_process; } if (nbytes == 0) { /* No data to process is valid */ - return 0; + rc = 0; + goto exit_process; } /*For CTS in case of data size aligned to 16 use CBC mode*/ if (((nbytes % AES_BLOCK_SIZE) == 0) && (ctx_p->cipher_mode == DRV_CIPHER_CBC_CTS)) { @@ -818,6 +838,9 @@ exit_process: if (cts_restore_flag != 0) ctx_p->cipher_mode = DRV_CIPHER_CBC_CTS; + if (rc != -EINPROGRESS) + kfree(req_ctx->backup_info); + return rc; } @@ -858,7 +881,6 @@ static int ssi_ablkcipher_encrypt(struct ablkcipher_request *req) struct blkcipher_req_ctx *req_ctx = ablkcipher_request_ctx(req); unsigned int ivsize = crypto_ablkcipher_ivsize(ablk_tfm); - req_ctx->backup_info = req->info; req_ctx->is_giv = false; return ssi_blkcipher_process(tfm, req_ctx, req->dst, req->src, req->nbytes, req->info, ivsize, (void *)req, DRV_CRYPTO_DIRECTION_ENCRYPT); @@ -871,8 +893,18 @@ static int ssi_ablkcipher_decrypt(struct ablkcipher_request *req) struct blkcipher_req_ctx *req_ctx = ablkcipher_request_ctx(req); unsigned int ivsize = crypto_ablkcipher_ivsize(ablk_tfm); - req_ctx->backup_info = req->info; + /* + * Allocate and save the last IV sized bytes of the source, which will + * be lost in case of in-place decryption and might be needed for CTS. + */ + req_ctx->backup_info = kmalloc(ivsize, GFP_KERNEL); + if (!req_ctx->backup_info) + return -ENOMEM; + + scatterwalk_map_and_copy(req_ctx->backup_info, req->src, + (req->nbytes - ivsize), ivsize, 0); req_ctx->is_giv = false; + return ssi_blkcipher_process(tfm, req_ctx, req->dst, req->src, req->nbytes, req->info, ivsize, (void *)req, DRV_CRYPTO_DIRECTION_DECRYPT); } |