diff options
Diffstat (limited to 'drivers/crypto/caam/caampkc.c')
| -rw-r--r-- | drivers/crypto/caam/caampkc.c | 87 |
1 files changed, 72 insertions, 15 deletions
diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c index d876f2344fd6..30ede9310f79 100644 --- a/drivers/crypto/caam/caampkc.c +++ b/drivers/crypto/caam/caampkc.c @@ -24,6 +24,10 @@ sizeof(struct rsa_priv_f2_pdb)) #define DESC_RSA_PRIV_F3_LEN (2 * CAAM_CMD_SZ + \ sizeof(struct rsa_priv_f3_pdb)) +#define CAAM_RSA_MAX_INPUT_SIZE 512 /* for a 4096-bit modulus */ + +/* buffer filled with zeros, used for padding */ +static u8 *zero_buffer; static void rsa_io_unmap(struct device *dev, struct rsa_edesc *edesc, struct akcipher_request *req) @@ -168,6 +172,13 @@ static void rsa_priv_f3_done(struct device *dev, u32 *desc, u32 err, akcipher_request_complete(req, err); } +/** + * Count leading zeros, need it to strip, from a given scatterlist + * + * @sgl : scatterlist to count zeros from + * @nbytes: number of zeros, in bytes, to strip + * @flags : operation flags + */ static int caam_rsa_count_leading_zeros(struct scatterlist *sgl, unsigned int nbytes, unsigned int flags) @@ -187,7 +198,8 @@ static int caam_rsa_count_leading_zeros(struct scatterlist *sgl, lzeros = 0; len = 0; while (nbytes > 0) { - while (len && !*buff) { + /* do not strip more than given bytes */ + while (len && !*buff && lzeros < nbytes) { lzeros++; len--; buff++; @@ -218,6 +230,7 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm); struct device *dev = ctx->dev; struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req); + struct caam_rsa_key *key = &ctx->key; struct rsa_edesc *edesc; gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? GFP_KERNEL : GFP_ATOMIC; @@ -225,20 +238,38 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, int sgc; int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes; int src_nents, dst_nents; + unsigned int diff_size = 0; int lzeros; - lzeros = caam_rsa_count_leading_zeros(req->src, req->src_len, sg_flags); - if (lzeros < 0) - return ERR_PTR(lzeros); - req->src_len -= lzeros; - req->src = scatterwalk_ffwd(req_ctx->src, req->src, lzeros); + if (req->src_len > key->n_sz) { + /* + * strip leading zeros and + * return the number of zeros to skip + */ + lzeros = caam_rsa_count_leading_zeros(req->src, req->src_len - + key->n_sz, sg_flags); + if (lzeros < 0) + return ERR_PTR(lzeros); + + req->src_len -= lzeros; + req->src = scatterwalk_ffwd(req_ctx->src, req->src, lzeros); + } else { + /* + * input src is less then n key modulus, + * so there will be zero padding + */ + diff_size = key->n_sz - req->src_len; + } src_nents = sg_nents_for_len(req->src, req->src_len); dst_nents = sg_nents_for_len(req->dst, req->dst_len); - if (src_nents > 1) - sec4_sg_len = src_nents; + if (!diff_size && src_nents == 1) + sec4_sg_len = 0; /* no need for an input hw s/g table */ + else + sec4_sg_len = src_nents + !!diff_size; + sec4_sg_index = sec4_sg_len; if (dst_nents > 1) sec4_sg_len += dst_nents; @@ -263,12 +294,14 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, } edesc->sec4_sg = (void *)edesc + sizeof(*edesc) + desclen; + if (diff_size) + dma_to_sec4_sg_one(edesc->sec4_sg, ctx->padding_dma, diff_size, + 0); + + if (sec4_sg_index) + sg_to_sec4_sg_last(req->src, src_nents, edesc->sec4_sg + + !!diff_size, 0); - sec4_sg_index = 0; - if (src_nents > 1) { - sg_to_sec4_sg_last(req->src, src_nents, edesc->sec4_sg, 0); - sec4_sg_index += src_nents; - } if (dst_nents > 1) sg_to_sec4_sg_last(req->dst, dst_nents, edesc->sec4_sg + sec4_sg_index, 0); @@ -289,6 +322,10 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, edesc->sec4_sg_bytes = sec4_sg_bytes; + print_hex_dump_debug("caampkc sec4_sg@" __stringify(__LINE__) ": ", + DUMP_PREFIX_ADDRESS, 16, 4, edesc->sec4_sg, + edesc->sec4_sg_bytes, 1); + return edesc; sec4_sg_fail: @@ -978,6 +1015,15 @@ static int caam_rsa_init_tfm(struct crypto_akcipher *tfm) return PTR_ERR(ctx->dev); } + ctx->padding_dma = dma_map_single(ctx->dev, zero_buffer, + CAAM_RSA_MAX_INPUT_SIZE - 1, + DMA_TO_DEVICE); + if (dma_mapping_error(ctx->dev, ctx->padding_dma)) { + dev_err(ctx->dev, "unable to map padding\n"); + caam_jr_free(ctx->dev); + return -ENOMEM; + } + return 0; } @@ -987,6 +1033,8 @@ static void caam_rsa_exit_tfm(struct crypto_akcipher *tfm) struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm); struct caam_rsa_key *key = &ctx->key; + dma_unmap_single(ctx->dev, ctx->padding_dma, CAAM_RSA_MAX_INPUT_SIZE - + 1, DMA_TO_DEVICE); caam_rsa_free_key(key); caam_jr_free(ctx->dev); } @@ -1029,17 +1077,26 @@ int caam_pkc_init(struct device *ctrldev) if (!pk_inst) return 0; + /* allocate zero buffer, used for padding input */ + zero_buffer = kzalloc(CAAM_RSA_MAX_INPUT_SIZE - 1, GFP_DMA | + GFP_KERNEL); + if (!zero_buffer) + return -ENOMEM; + err = crypto_register_akcipher(&caam_rsa); - if (err) + if (err) { + kfree(zero_buffer); dev_warn(ctrldev, "%s alg registration failed\n", caam_rsa.base.cra_driver_name); - else + } else { dev_info(ctrldev, "caam pkc algorithms registered in /proc/crypto\n"); + } return err; } void caam_pkc_exit(void) { + kfree(zero_buffer); crypto_unregister_akcipher(&caam_rsa); } |