crypto: ccp - Add support for valid authsize values less than 16

[mirror_ubuntu-bionic-kernel.git] / drivers / crypto / ccp / ccp-ops.c

diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
index ec005fb652c5908d84bc9f099824186d64946f2d..1e2e42106dee070d92ac543c8e1448327caffb8a 100644 (file)
--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -625,6 +625,7 @@ static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q,
 
        unsigned long long *final;
        unsigned int dm_offset;
+       unsigned int authsize;
        unsigned int jobid;
        unsigned int ilen;
        bool in_place = true; /* Default value */
@@ -646,6 +647,21 @@ static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q,
        if (!aes->key) /* Gotta have a key SGL */
                return -EINVAL;
 
+       /* Zero defaults to 16 bytes, the maximum size */
+       authsize = aes->authsize ? aes->authsize : AES_BLOCK_SIZE;
+       switch (authsize) {
+       case 16:
+       case 15:
+       case 14:
+       case 13:
+       case 12:
+       case 8:
+       case 4:
+               break;
+       default:
+               return -EINVAL;
+       }
+
        /* First, decompose the source buffer into AAD & PT,
         * and the destination buffer into AAD, CT & tag, or
         * the input into CT & tag.
@@ -660,7 +676,7 @@ static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q,
                p_tag = scatterwalk_ffwd(sg_tag, p_outp, ilen);
        } else {
                /* Input length for decryption includes tag */
-               ilen = aes->src_len - AES_BLOCK_SIZE;
+               ilen = aes->src_len - authsize;
                p_tag = scatterwalk_ffwd(sg_tag, p_inp, ilen);
        }
 
@@ -841,19 +857,19 @@ static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q,
 
        if (aes->action == CCP_AES_ACTION_ENCRYPT) {
                /* Put the ciphered tag after the ciphertext. */
-               ccp_get_dm_area(&final_wa, 0, p_tag, 0, AES_BLOCK_SIZE);
+               ccp_get_dm_area(&final_wa, 0, p_tag, 0, authsize);
        } else {
                /* Does this ciphered tag match the input? */
-               ret = ccp_init_dm_workarea(&tag, cmd_q, AES_BLOCK_SIZE,
+               ret = ccp_init_dm_workarea(&tag, cmd_q, authsize,
                                           DMA_BIDIRECTIONAL);
                if (ret)
                        goto e_tag;
-               ret = ccp_set_dm_area(&tag, 0, p_tag, 0, AES_BLOCK_SIZE);
+               ret = ccp_set_dm_area(&tag, 0, p_tag, 0, authsize);
                if (ret)
                        goto e_tag;
 
                ret = crypto_memneq(tag.address, final_wa.address,
-                                   AES_BLOCK_SIZE) ? -EBADMSG : 0;
+                                   authsize) ? -EBADMSG : 0;
                ccp_dm_free(&tag);
        }