2 * AMD Cryptographic Coprocessor (CCP) AES CMAC crypto API support
4 * Copyright (C) 2013 Advanced Micro Devices, Inc.
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/module.h>
14 #include <linux/sched.h>
15 #include <linux/delay.h>
16 #include <linux/scatterlist.h>
17 #include <linux/crypto.h>
18 #include <crypto/algapi.h>
19 #include <crypto/aes.h>
20 #include <crypto/hash.h>
21 #include <crypto/internal/hash.h>
22 #include <crypto/scatterwalk.h>
24 #include "ccp-crypto.h"
26 static int ccp_aes_cmac_complete(struct crypto_async_request *async_req,
29 struct ahash_request *req = ahash_request_cast(async_req);
30 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
31 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
32 unsigned int digest_size = crypto_ahash_digestsize(tfm);
38 /* Save remaining data to buffer */
39 unsigned int offset = rctx->nbytes - rctx->hash_rem;
41 scatterwalk_map_and_copy(rctx->buf, rctx->src,
42 offset, rctx->hash_rem, 0);
43 rctx->buf_count = rctx->hash_rem;
48 /* Update result area if supplied */
50 memcpy(req->result, rctx->iv, digest_size);
53 sg_free_table(&rctx->data_sg);
58 static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes,
61 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
62 struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
63 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
64 struct scatterlist *sg, *cmac_key_sg = NULL;
65 unsigned int block_size =
66 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
67 unsigned int need_pad, sg_count;
72 if (!ctx->u.aes.key_len)
78 len = (u64)rctx->buf_count + (u64)nbytes;
80 if (!final && (len <= block_size)) {
81 scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
83 rctx->buf_count += nbytes;
89 rctx->nbytes = nbytes;
92 rctx->hash_rem = final ? 0 : len & (block_size - 1);
93 rctx->hash_cnt = len - rctx->hash_rem;
94 if (!final && !rctx->hash_rem) {
95 /* CCP can't do zero length final, so keep some data around */
96 rctx->hash_cnt -= block_size;
97 rctx->hash_rem = block_size;
100 if (final && (rctx->null_msg || (len & (block_size - 1))))
105 sg_init_one(&rctx->iv_sg, rctx->iv, sizeof(rctx->iv));
107 /* Build the data scatterlist table - allocate enough entries for all
108 * possible data pieces (buffer, input data, padding)
110 sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2;
111 gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
112 GFP_KERNEL : GFP_ATOMIC;
113 ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
118 if (rctx->buf_count) {
119 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
120 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
128 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
136 int pad_length = block_size - (len & (block_size - 1));
138 rctx->hash_cnt += pad_length;
140 memset(rctx->pad, 0, sizeof(rctx->pad));
142 sg_init_one(&rctx->pad_sg, rctx->pad, pad_length);
143 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg);
151 sg = rctx->data_sg.sgl;
154 /* Initialize the K1/K2 scatterlist */
156 cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg
159 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
160 INIT_LIST_HEAD(&rctx->cmd.entry);
161 rctx->cmd.engine = CCP_ENGINE_AES;
162 rctx->cmd.u.aes.type = ctx->u.aes.type;
163 rctx->cmd.u.aes.mode = ctx->u.aes.mode;
164 rctx->cmd.u.aes.action = CCP_AES_ACTION_ENCRYPT;
165 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
166 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
167 rctx->cmd.u.aes.iv = &rctx->iv_sg;
168 rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE;
169 rctx->cmd.u.aes.src = sg;
170 rctx->cmd.u.aes.src_len = rctx->hash_cnt;
171 rctx->cmd.u.aes.dst = NULL;
172 rctx->cmd.u.aes.cmac_key = cmac_key_sg;
173 rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len;
174 rctx->cmd.u.aes.cmac_final = final;
176 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
181 sg_free_table(&rctx->data_sg);
186 static int ccp_aes_cmac_init(struct ahash_request *req)
188 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
190 memset(rctx, 0, sizeof(*rctx));
197 static int ccp_aes_cmac_update(struct ahash_request *req)
199 return ccp_do_cmac_update(req, req->nbytes, 0);
202 static int ccp_aes_cmac_final(struct ahash_request *req)
204 return ccp_do_cmac_update(req, 0, 1);
207 static int ccp_aes_cmac_finup(struct ahash_request *req)
209 return ccp_do_cmac_update(req, req->nbytes, 1);
212 static int ccp_aes_cmac_digest(struct ahash_request *req)
216 ret = ccp_aes_cmac_init(req);
220 return ccp_aes_cmac_finup(req);
223 static int ccp_aes_cmac_export(struct ahash_request *req, void *out)
225 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
226 struct ccp_aes_cmac_exp_ctx *state = out;
228 state->null_msg = rctx->null_msg;
229 memcpy(state->iv, rctx->iv, sizeof(state->iv));
230 state->buf_count = rctx->buf_count;
231 memcpy(state->buf, rctx->buf, sizeof(state->buf));
236 static int ccp_aes_cmac_import(struct ahash_request *req, const void *in)
238 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
239 const struct ccp_aes_cmac_exp_ctx *state = in;
241 rctx->null_msg = state->null_msg;
242 memcpy(rctx->iv, state->iv, sizeof(rctx->iv));
243 rctx->buf_count = state->buf_count;
244 memcpy(rctx->buf, state->buf, sizeof(rctx->buf));
249 static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key,
250 unsigned int key_len)
252 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
253 struct ccp_crypto_ahash_alg *alg =
254 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
255 u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo;
256 u64 rb_hi = 0x00, rb_lo = 0x87;
261 case AES_KEYSIZE_128:
262 ctx->u.aes.type = CCP_AES_TYPE_128;
264 case AES_KEYSIZE_192:
265 ctx->u.aes.type = CCP_AES_TYPE_192;
267 case AES_KEYSIZE_256:
268 ctx->u.aes.type = CCP_AES_TYPE_256;
271 crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
274 ctx->u.aes.mode = alg->mode;
276 /* Set to zero until complete */
277 ctx->u.aes.key_len = 0;
279 /* Set the key for the AES cipher used to generate the keys */
280 ret = crypto_cipher_setkey(ctx->u.aes.tfm_cipher, key, key_len);
284 /* Encrypt a block of zeroes - use key area in context */
285 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key));
286 crypto_cipher_encrypt_one(ctx->u.aes.tfm_cipher, ctx->u.aes.key,
289 /* Generate K1 and K2 */
290 k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key));
291 k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1));
293 k1_hi = (k0_hi << 1) | (k0_lo >> 63);
295 if (ctx->u.aes.key[0] & 0x80) {
299 gk = (__be64 *)ctx->u.aes.k1;
300 *gk = cpu_to_be64(k1_hi);
302 *gk = cpu_to_be64(k1_lo);
304 k2_hi = (k1_hi << 1) | (k1_lo >> 63);
306 if (ctx->u.aes.k1[0] & 0x80) {
310 gk = (__be64 *)ctx->u.aes.k2;
311 *gk = cpu_to_be64(k2_hi);
313 *gk = cpu_to_be64(k2_lo);
315 ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1);
316 sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1));
317 sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2));
319 /* Save the supplied key */
320 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key));
321 memcpy(ctx->u.aes.key, key, key_len);
322 ctx->u.aes.key_len = key_len;
323 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
328 static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm)
330 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
331 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
332 struct crypto_cipher *cipher_tfm;
334 ctx->complete = ccp_aes_cmac_complete;
335 ctx->u.aes.key_len = 0;
337 crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_aes_cmac_req_ctx));
339 cipher_tfm = crypto_alloc_cipher("aes", 0,
341 CRYPTO_ALG_NEED_FALLBACK);
342 if (IS_ERR(cipher_tfm)) {
343 pr_warn("could not load aes cipher driver\n");
344 return PTR_ERR(cipher_tfm);
346 ctx->u.aes.tfm_cipher = cipher_tfm;
351 static void ccp_aes_cmac_cra_exit(struct crypto_tfm *tfm)
353 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
355 if (ctx->u.aes.tfm_cipher)
356 crypto_free_cipher(ctx->u.aes.tfm_cipher);
357 ctx->u.aes.tfm_cipher = NULL;
360 int ccp_register_aes_cmac_algs(struct list_head *head)
362 struct ccp_crypto_ahash_alg *ccp_alg;
363 struct ahash_alg *alg;
364 struct hash_alg_common *halg;
365 struct crypto_alg *base;
368 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
372 INIT_LIST_HEAD(&ccp_alg->entry);
373 ccp_alg->mode = CCP_AES_MODE_CMAC;
376 alg->init = ccp_aes_cmac_init;
377 alg->update = ccp_aes_cmac_update;
378 alg->final = ccp_aes_cmac_final;
379 alg->finup = ccp_aes_cmac_finup;
380 alg->digest = ccp_aes_cmac_digest;
381 alg->export = ccp_aes_cmac_export;
382 alg->import = ccp_aes_cmac_import;
383 alg->setkey = ccp_aes_cmac_setkey;
386 halg->digestsize = AES_BLOCK_SIZE;
387 halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx);
390 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)");
391 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp");
392 base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC |
393 CRYPTO_ALG_KERN_DRIVER_ONLY |
394 CRYPTO_ALG_NEED_FALLBACK;
395 base->cra_blocksize = AES_BLOCK_SIZE;
396 base->cra_ctxsize = sizeof(struct ccp_ctx);
397 base->cra_priority = CCP_CRA_PRIORITY;
398 base->cra_type = &crypto_ahash_type;
399 base->cra_init = ccp_aes_cmac_cra_init;
400 base->cra_exit = ccp_aes_cmac_cra_exit;
401 base->cra_module = THIS_MODULE;
403 ret = crypto_register_ahash(alg);
405 pr_err("%s ahash algorithm registration error (%d)\n",
406 base->cra_name, ret);
411 list_add(&ccp_alg->entry, head);