Add support for AES working in XEX-based Tweaked-codebook mode with
ciphertext Stealing (XTS)
sector index - HW limitation: CAAM device supports sector index of only
8 bytes to be used for sector index inside IV, instead of whole 16 bytes
received on request. This represents 2 ^ 64 = 16,777,216 Tera of possible
values for sector index.
Signed-off-by: Cristian Hristea <cristi.hristea@xxxxxxxxx>
Signed-off-by: Horia Geanta <horia.geanta@xxxxxxxxxxxxx>
Signed-off-by: Alex Porosanu <alexandru.porosanu@xxxxxxxxxxxxx>
Signed-off-by: Catalin Vasile <catalin.vasile@xxxxxxxxxxxxx>
---
drivers/crypto/caam/caamalg.c | 138 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 137 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index ad0d1ec..ea8189f 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -1705,6 +1705,126 @@ static int ablkcipher_setkey(struct crypto_ablkcipher *ablkcipher,
return ret;
}
+static int xts_ablkcipher_setkey(struct crypto_ablkcipher *ablkcipher,
+ const u8 *key, unsigned int keylen)
+{
+ struct caam_ctx *ctx = crypto_ablkcipher_ctx(ablkcipher);
+ struct device *jrdev = ctx->jrdev;
+ u32 *key_jump_cmd, *desc;
+ __be64 sector_size = cpu_to_be64(512);
+
+ if (keylen != 2 * AES_MIN_KEY_SIZE && keylen != 2 * AES_MAX_KEY_SIZE) {
+ crypto_ablkcipher_set_flags(ablkcipher,
+ CRYPTO_TFM_RES_BAD_KEY_LEN);
+ dev_err(jrdev, "key size mismatch\n");
+ return -EINVAL;
+ }
+
+ memcpy(ctx->key, key, keylen);
+ ctx->key_dma = dma_map_single(jrdev, ctx->key, keylen, DMA_TO_DEVICE);
+ if (dma_mapping_error(jrdev, ctx->key_dma)) {
+ dev_err(jrdev, "unable to map key i/o memory\n");
+ return -ENOMEM;
+ }
+ ctx->enckeylen = keylen;
+
+ /* xts_ablkcipher_encrypt shared descriptor */
+ desc = ctx->sh_desc_enc;
+ init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
+ /* Skip if already shared */
+ key_jump_cmd = append_jump(desc, JUMP_JSL | JUMP_TEST_ALL |
+ JUMP_COND_SHRD);
+
+ /* Load class1 keys only */
+ append_key_as_imm(desc, (void *)ctx->key, ctx->enckeylen,
+ ctx->enckeylen, CLASS_1 | KEY_DEST_CLASS_REG);
+
+ /* Load sector size with index 40 bytes (0x28) */
+ append_cmd(desc, CMD_LOAD | IMMEDIATE | LDST_SRCDST_BYTE_CONTEXT |
+ LDST_CLASS_1_CCB | (0x28 << LDST_OFFSET_SHIFT) | 8);
+ append_data(desc, (void *)§or_size, 8);
+
+ set_jump_tgt_here(desc, key_jump_cmd);
+
+ /*
+ * create sequence for loading the sector index
+ * Upper 8B of IV - will be used as sector index
+ * Lower 8B of IV - will be discarded
+ */
+ append_cmd(desc, CMD_SEQ_LOAD | LDST_SRCDST_BYTE_CONTEXT |
+ LDST_CLASS_1_CCB | (0x20 << LDST_OFFSET_SHIFT) | 8);
+ append_seq_fifo_load(desc, 8, FIFOLD_CLASS_SKIP);
+
+ /* Load operation */
+ append_operation(desc, ctx->class1_alg_type | OP_ALG_AS_INITFINAL |
+ OP_ALG_ENCRYPT);
+
+ /* Perform operation */
+ ablkcipher_append_src_dst(desc);
+
+ ctx->sh_desc_enc_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(jrdev, ctx->sh_desc_enc_dma)) {
+ dev_err(jrdev, "unable to map shared descriptor\n");
+ return -ENOMEM;
+ }
+#ifdef DEBUG
+ print_hex_dump(KERN_ERR,
+ "xts ablkcipher enc shdesc@" __stringify(__LINE__) ": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
+#endif
+
+ /* xts_ablkcipher_decrypt shared descriptor */
+ desc = ctx->sh_desc_dec;
+
+ init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
+ /* Skip if already shared */
+ key_jump_cmd = append_jump(desc, JUMP_JSL | JUMP_TEST_ALL |
+ JUMP_COND_SHRD);
+
+ /* Load class1 key only */
+ append_key_as_imm(desc, (void *)ctx->key, ctx->enckeylen,
+ ctx->enckeylen, CLASS_1 | KEY_DEST_CLASS_REG);
+
+ /* Load sector size with index 40 bytes (0x28) */
+ append_cmd(desc, CMD_LOAD | IMMEDIATE | LDST_SRCDST_BYTE_CONTEXT |
+ LDST_CLASS_1_CCB | (0x28 << LDST_OFFSET_SHIFT) | 8);
+ append_data(desc, (void *)§or_size, 8);
+
+ set_jump_tgt_here(desc, key_jump_cmd);
+
+ /*
+ * create sequence for loading the sector index
+ * Upper 8B of IV - will be used as sector index
+ * Lower 8B of IV - will be discarded
+ */
+ append_cmd(desc, CMD_SEQ_LOAD | LDST_SRCDST_BYTE_CONTEXT |
+ LDST_CLASS_1_CCB | (0x20 << LDST_OFFSET_SHIFT) | 8);
+ append_seq_fifo_load(desc, 8, FIFOLD_CLASS_SKIP);
+
+ /* Load operation */
+ append_dec_op1(desc, ctx->class1_alg_type);
+
+ /* Perform operation */
+ ablkcipher_append_src_dst(desc);
+
+ ctx->sh_desc_dec_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(jrdev, ctx->sh_desc_dec_dma)) {
+ dma_unmap_single(jrdev, ctx->sh_desc_enc_dma,
+ desc_bytes(ctx->sh_desc_enc), DMA_TO_DEVICE);
+ dev_err(jrdev, "unable to map shared descriptor\n");
+ return -ENOMEM;
+ }
+#ifdef DEBUG
+ print_hex_dump(KERN_ERR,
+ "xts ablkcipher dec shdesc@" __stringify(__LINE__) ": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
+#endif
+
+ return 0;
+}
+
/*
* aead_edesc - s/w-extended aead descriptor
* @assoc_nents: number of segments in associated data (SPI+Seq) scatterlist
@@ -2845,7 +2965,23 @@ static struct caam_alg_template driver_algs[] = {
.ivsize = CTR_RFC3686_IV_SIZE,
},
.class1_alg_type = OP_ALG_ALGSEL_AES | OP_ALG_AAI_CTR_MOD128,
- }
+ },
+ {
+ .name = "xts(aes)",
+ .driver_name = "xts-aes-caam",
+ .blocksize = AES_BLOCK_SIZE,
+ .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+ .template_ablkcipher = {
+ .setkey = xts_ablkcipher_setkey,
+ .encrypt = ablkcipher_encrypt,
+ .decrypt = ablkcipher_decrypt,
+ .geniv = "eseqiv",
+ .min_keysize = 2 * AES_MIN_KEY_SIZE,
+ .max_keysize = 2 * AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ },
+ .class1_alg_type = OP_ALG_ALGSEL_AES | OP_ALG_AAI_XTS,
+ },
};
static struct caam_aead_alg driver_aeads[] = {
--
1.8.3.1
--
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