nx-aes-ccm.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * AES CCM routines supporting the Power 7+ Nest Accelerators driver
  4 *
  5 * Copyright (C) 2012 International Business Machines Inc.
  6 *
  7 * Author: Kent Yoder <yoder1@us.ibm.com>
  8 */
  9
 10#include <crypto/internal/aead.h>
 11#include <crypto/aes.h>
 12#include <crypto/algapi.h>
 13#include <crypto/scatterwalk.h>
 14#include <linux/module.h>
 15#include <linux/types.h>
 16#include <linux/crypto.h>
 17#include <asm/vio.h>
 18
 19#include "nx_csbcpb.h"
 20#include "nx.h"
 21
 22
 23static int ccm_aes_nx_set_key(struct crypto_aead *tfm,
 24			      const u8           *in_key,
 25			      unsigned int        key_len)
 26{
 27	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
 28	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 29	struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
 30
 31	nx_ctx_init(nx_ctx, HCOP_FC_AES);
 32
 33	switch (key_len) {
 34	case AES_KEYSIZE_128:
 35		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
 36		NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
 37		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
 38		break;
 39	default:
 40		return -EINVAL;
 41	}
 42
 43	csbcpb->cpb.hdr.mode = NX_MODE_AES_CCM;
 44	memcpy(csbcpb->cpb.aes_ccm.key, in_key, key_len);
 45
 46	csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_CCA;
 47	memcpy(csbcpb_aead->cpb.aes_cca.key, in_key, key_len);
 48
 49	return 0;
 50
 51}
 52
 53static int ccm4309_aes_nx_set_key(struct crypto_aead *tfm,
 54				  const u8           *in_key,
 55				  unsigned int        key_len)
 56{
 57	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
 58
 59	if (key_len < 3)
 60		return -EINVAL;
 61
 62	key_len -= 3;
 63
 64	memcpy(nx_ctx->priv.ccm.nonce, in_key + key_len, 3);
 65
 66	return ccm_aes_nx_set_key(tfm, in_key, key_len);
 67}
 68
 69static int ccm_aes_nx_setauthsize(struct crypto_aead *tfm,
 70				  unsigned int authsize)
 71{
 72	switch (authsize) {
 73	case 4:
 74	case 6:
 75	case 8:
 76	case 10:
 77	case 12:
 78	case 14:
 79	case 16:
 80		break;
 81	default:
 82		return -EINVAL;
 83	}
 84
 85	return 0;
 86}
 87
 88static int ccm4309_aes_nx_setauthsize(struct crypto_aead *tfm,
 89				      unsigned int authsize)
 90{
 91	switch (authsize) {
 92	case 8:
 93	case 12:
 94	case 16:
 95		break;
 96	default:
 97		return -EINVAL;
 98	}
 99
100	return 0;
101}
102
103/* taken from crypto/ccm.c */
104static int set_msg_len(u8 *block, unsigned int msglen, int csize)
105{
106	__be32 data;
107
108	memset(block, 0, csize);
109	block += csize;
110
111	if (csize >= 4)
112		csize = 4;
113	else if (msglen > (unsigned int)(1 << (8 * csize)))
114		return -EOVERFLOW;
115
116	data = cpu_to_be32(msglen);
117	memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
118
119	return 0;
120}
121
122/* taken from crypto/ccm.c */
123static inline int crypto_ccm_check_iv(const u8 *iv)
124{
125	/* 2 <= L <= 8, so 1 <= L' <= 7. */
126	if (1 > iv[0] || iv[0] > 7)
127		return -EINVAL;
128
129	return 0;
130}
131
132/* based on code from crypto/ccm.c */
133static int generate_b0(u8 *iv, unsigned int assoclen, unsigned int authsize,
134		       unsigned int cryptlen, u8 *b0)
135{
136	unsigned int l, lp, m = authsize;
137
138	memcpy(b0, iv, 16);
139
140	lp = b0[0];
141	l = lp + 1;
142
143	/* set m, bits 3-5 */
144	*b0 |= (8 * ((m - 2) / 2));
145
146	/* set adata, bit 6, if associated data is used */
147	if (assoclen)
148		*b0 |= 64;
149
150	return set_msg_len(b0 + 16 - l, cryptlen, l);
151}
152
153static int generate_pat(u8                   *iv,
154			struct aead_request  *req,
155			struct nx_crypto_ctx *nx_ctx,
156			unsigned int          authsize,
157			unsigned int          nbytes,
158			unsigned int	      assoclen,
159			u8                   *out)
160{
161	struct nx_sg *nx_insg = nx_ctx->in_sg;
162	struct nx_sg *nx_outsg = nx_ctx->out_sg;
163	unsigned int iauth_len = 0;
164	u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL;
165	int rc;
166	unsigned int max_sg_len;
167
168	/* zero the ctr value */
169	memset(iv + 15 - iv[0], 0, iv[0] + 1);
170
171	/* page 78 of nx_wb.pdf has,
172	 * Note: RFC3610 allows the AAD data to be up to 2^64 -1 bytes
173	 * in length. If a full message is used, the AES CCA implementation
174	 * restricts the maximum AAD length to 2^32 -1 bytes.
175	 * If partial messages are used, the implementation supports
176	 * 2^64 -1 bytes maximum AAD length.
177	 *
178	 * However, in the cryptoapi's aead_request structure,
179	 * assoclen is an unsigned int, thus it cannot hold a length
180	 * value greater than 2^32 - 1.
181	 * Thus the AAD is further constrained by this and is never
182	 * greater than 2^32.
183	 */
184
185	if (!assoclen) {
186		b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
187	} else if (assoclen <= 14) {
188		/* if associated data is 14 bytes or less, we do 1 GCM
189		 * operation on 2 AES blocks, B0 (stored in the csbcpb) and B1,
190		 * which is fed in through the source buffers here */
191		b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
192		b1 = nx_ctx->priv.ccm.iauth_tag;
193		iauth_len = assoclen;
194	} else if (assoclen <= 65280) {
195		/* if associated data is less than (2^16 - 2^8), we construct
196		 * B1 differently and feed in the associated data to a CCA
197		 * operation */
198		b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
199		b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
200		iauth_len = 14;
201	} else {
202		b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
203		b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
204		iauth_len = 10;
205	}
206
207	/* generate B0 */
208	rc = generate_b0(iv, assoclen, authsize, nbytes, b0);
209	if (rc)
210		return rc;
211
212	/* generate B1:
213	 * add control info for associated data
214	 * RFC 3610 and NIST Special Publication 800-38C
215	 */
216	if (b1) {
217		memset(b1, 0, 16);
218		if (assoclen <= 65280) {
219			*(u16 *)b1 = assoclen;
220			memcpy_from_sglist(b1 + 2, req->src, 0, iauth_len);
221		} else {
222			*(u16 *)b1 = (u16)(0xfffe);
223			*(u32 *)&b1[2] = assoclen;
224			memcpy_from_sglist(b1 + 6, req->src, 0, iauth_len);
225		}
226	}
227
228	/* now copy any remaining AAD to scatterlist and call nx... */
229	if (!assoclen) {
230		return rc;
231	} else if (assoclen <= 14) {
232		unsigned int len = 16;
233
234		nx_insg = nx_build_sg_list(nx_insg, b1, &len, nx_ctx->ap->sglen);
235
236		if (len != 16)
237			return -EINVAL;
238
239		nx_outsg = nx_build_sg_list(nx_outsg, tmp, &len,
240					    nx_ctx->ap->sglen);
241
242		if (len != 16)
243			return -EINVAL;
244
245		/* inlen should be negative, indicating to phyp that its a
246		 * pointer to an sg list */
247		nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) *
248					sizeof(struct nx_sg);
249		nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) *
250					sizeof(struct nx_sg);
251
252		NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT;
253		NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE;
254
255		result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac;
256
257		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
258				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
259		if (rc)
260			return rc;
261
262		atomic_inc(&(nx_ctx->stats->aes_ops));
263		atomic64_add(assoclen, &nx_ctx->stats->aes_bytes);
264
265	} else {
266		unsigned int processed = 0, to_process;
267
268		processed += iauth_len;
269
270		/* page_limit: number of sg entries that fit on one page */
271		max_sg_len = min_t(u64, nx_ctx->ap->sglen,
272				nx_driver.of.max_sg_len/sizeof(struct nx_sg));
273		max_sg_len = min_t(u64, max_sg_len,
274				nx_ctx->ap->databytelen/NX_PAGE_SIZE);
275
276		do {
277			to_process = min_t(u32, assoclen - processed,
278					   nx_ctx->ap->databytelen);
279
280			nx_insg = nx_walk_and_build(nx_ctx->in_sg,
281						    nx_ctx->ap->sglen,
282						    req->src, processed,
283						    &to_process);
284
285			if ((to_process + processed) < assoclen) {
286				NX_CPB_FDM(nx_ctx->csbcpb_aead) |=
287					NX_FDM_INTERMEDIATE;
288			} else {
289				NX_CPB_FDM(nx_ctx->csbcpb_aead) &=
290					~NX_FDM_INTERMEDIATE;
291			}
292
293
294			nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) *
295						sizeof(struct nx_sg);
296
297			result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0;
298
299			rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,
300				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
301			if (rc)
302				return rc;
303
304			memcpy(nx_ctx->csbcpb_aead->cpb.aes_cca.b0,
305				nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0,
306				AES_BLOCK_SIZE);
307
308			NX_CPB_FDM(nx_ctx->csbcpb_aead) |= NX_FDM_CONTINUATION;
309
310			atomic_inc(&(nx_ctx->stats->aes_ops));
311			atomic64_add(assoclen, &nx_ctx->stats->aes_bytes);
312
313			processed += to_process;
314		} while (processed < assoclen);
315
316		result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0;
317	}
318
319	memcpy(out, result, AES_BLOCK_SIZE);
320
321	return rc;
322}
323
324static int ccm_nx_decrypt(struct aead_request   *req,
325			  u8                    *iv,
326			  unsigned int assoclen)
327{
328	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
329	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
330	unsigned int nbytes = req->cryptlen;
331	unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
332	struct nx_ccm_priv *priv = &nx_ctx->priv.ccm;
333	unsigned long irq_flags;
334	unsigned int processed = 0, to_process;
335	int rc = -1;
336
337	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
338
339	nbytes -= authsize;
340
341	/* copy out the auth tag to compare with later */
342	memcpy_from_sglist(priv->oauth_tag, req->src, nbytes + req->assoclen,
343			   authsize);
344
345	rc = generate_pat(iv, req, nx_ctx, authsize, nbytes, assoclen,
346			  csbcpb->cpb.aes_ccm.in_pat_or_b0);
347	if (rc)
348		goto out;
349
350	do {
351
352		/* to_process: the AES_BLOCK_SIZE data chunk to process in this
353		 * update. This value is bound by sg list limits.
354		 */
355		to_process = nbytes - processed;
356
357		if ((to_process + processed) < nbytes)
358			NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
359		else
360			NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
361
362		NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
363
364		rc = nx_build_sg_lists(nx_ctx, iv, req->dst, req->src,
365				       &to_process, processed + req->assoclen,
366				       csbcpb->cpb.aes_ccm.iv_or_ctr);
367		if (rc)
368			goto out;
369
370		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
371			   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
372		if (rc)
373			goto out;
374
375		/* for partial completion, copy following for next
376		 * entry into loop...
377		 */
378		memcpy(iv, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE);
379		memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0,
380			csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE);
381		memcpy(csbcpb->cpb.aes_ccm.in_s0,
382			csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE);
383
384		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
385
386		/* update stats */
387		atomic_inc(&(nx_ctx->stats->aes_ops));
388		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
389			     &(nx_ctx->stats->aes_bytes));
390
391		processed += to_process;
392	} while (processed < nbytes);
393
394	rc = crypto_memneq(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag,
395		    authsize) ? -EBADMSG : 0;
396out:
397	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
398	return rc;
399}
400
401static int ccm_nx_encrypt(struct aead_request   *req,
402			  u8                    *iv,
403			  unsigned int assoclen)
404{
405	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
406	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
407	unsigned int nbytes = req->cryptlen;
408	unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
409	unsigned long irq_flags;
410	unsigned int processed = 0, to_process;
411	int rc = -1;
412
413	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
414
415	rc = generate_pat(iv, req, nx_ctx, authsize, nbytes, assoclen,
416			  csbcpb->cpb.aes_ccm.in_pat_or_b0);
417	if (rc)
418		goto out;
419
420	do {
421		/* to process: the AES_BLOCK_SIZE data chunk to process in this
422		 * update. This value is bound by sg list limits.
423		 */
424		to_process = nbytes - processed;
425
426		if ((to_process + processed) < nbytes)
427			NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
428		else
429			NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
430
431		NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
432
433		rc = nx_build_sg_lists(nx_ctx, iv, req->dst, req->src,
434				       &to_process, processed + req->assoclen,
435				       csbcpb->cpb.aes_ccm.iv_or_ctr);
436		if (rc)
437			goto out;
438
439		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
440				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
441		if (rc)
442			goto out;
443
444		/* for partial completion, copy following for next
445		 * entry into loop...
446		 */
447		memcpy(iv, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE);
448		memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0,
449			csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE);
450		memcpy(csbcpb->cpb.aes_ccm.in_s0,
451			csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE);
452
453		NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
454
455		/* update stats */
456		atomic_inc(&(nx_ctx->stats->aes_ops));
457		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
458			     &(nx_ctx->stats->aes_bytes));
459
460		processed += to_process;
461
462	} while (processed < nbytes);
463
464	/* copy out the auth tag */
465	memcpy_to_sglist(req->dst, nbytes + req->assoclen,
466			 csbcpb->cpb.aes_ccm.out_pat_or_mac, authsize);
467
468out:
469	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
470	return rc;
471}
472
473static int ccm4309_aes_nx_encrypt(struct aead_request *req)
474{
475	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
476	struct nx_gcm_rctx *rctx = aead_request_ctx(req);
477	u8 *iv = rctx->iv;
478
479	iv[0] = 3;
480	memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3);
481	memcpy(iv + 4, req->iv, 8);
482
483	return ccm_nx_encrypt(req, iv, req->assoclen - 8);
484}
485
486static int ccm_aes_nx_encrypt(struct aead_request *req)
487{
488	int rc;
489
490	rc = crypto_ccm_check_iv(req->iv);
491	if (rc)
492		return rc;
493
494	return ccm_nx_encrypt(req, req->iv, req->assoclen);
495}
496
497static int ccm4309_aes_nx_decrypt(struct aead_request *req)
498{
499	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
500	struct nx_gcm_rctx *rctx = aead_request_ctx(req);
501	u8 *iv = rctx->iv;
502
503	iv[0] = 3;
504	memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3);
505	memcpy(iv + 4, req->iv, 8);
506
507	return ccm_nx_decrypt(req, iv, req->assoclen - 8);
508}
509
510static int ccm_aes_nx_decrypt(struct aead_request *req)
511{
512	int rc;
513
514	rc = crypto_ccm_check_iv(req->iv);
515	if (rc)
516		return rc;
517
518	return ccm_nx_decrypt(req, req->iv, req->assoclen);
519}
520
521struct aead_alg nx_ccm_aes_alg = {
522	.base = {
523		.cra_name        = "ccm(aes)",
524		.cra_driver_name = "ccm-aes-nx",
525		.cra_priority    = 300,
526		.cra_flags       = CRYPTO_ALG_NEED_FALLBACK,
527		.cra_blocksize   = 1,
528		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
529		.cra_module      = THIS_MODULE,
530	},
531	.init        = nx_crypto_ctx_aes_ccm_init,
532	.exit        = nx_crypto_ctx_aead_exit,
533	.ivsize      = AES_BLOCK_SIZE,
534	.maxauthsize = AES_BLOCK_SIZE,
535	.setkey      = ccm_aes_nx_set_key,
536	.setauthsize = ccm_aes_nx_setauthsize,
537	.encrypt     = ccm_aes_nx_encrypt,
538	.decrypt     = ccm_aes_nx_decrypt,
539};
540
541struct aead_alg nx_ccm4309_aes_alg = {
542	.base = {
543		.cra_name        = "rfc4309(ccm(aes))",
544		.cra_driver_name = "rfc4309-ccm-aes-nx",
545		.cra_priority    = 300,
546		.cra_flags       = CRYPTO_ALG_NEED_FALLBACK,
547		.cra_blocksize   = 1,
548		.cra_ctxsize     = sizeof(struct nx_crypto_ctx),
549		.cra_module      = THIS_MODULE,
550	},
551	.init        = nx_crypto_ctx_aes_ccm_init,
552	.exit        = nx_crypto_ctx_aead_exit,
553	.ivsize      = 8,
554	.maxauthsize = AES_BLOCK_SIZE,
555	.setkey      = ccm4309_aes_nx_set_key,
556	.setauthsize = ccm4309_aes_nx_setauthsize,
557	.encrypt     = ccm4309_aes_nx_encrypt,
558	.decrypt     = ccm4309_aes_nx_decrypt,
559};