xref: /titanic_41/usr/src/common/crypto/modes/gcm.c (revision 5fbb41393be5d63f75952b1d72d4df2642d22557)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef _KERNEL
27 #include <strings.h>
28 #include <limits.h>
29 #include <assert.h>
30 #include <security/cryptoki.h>
31 #endif
32 
33 #include <sys/types.h>
34 #include <sys/kmem.h>
35 #include <modes/modes.h>
36 #include <sys/crypto/common.h>
37 #include <sys/crypto/impl.h>
38 #include <sys/byteorder.h>
39 
40 struct aes_block {
41 	uint64_t a;
42 	uint64_t b;
43 };
44 
45 void
46 gcm_mul(uint64_t *x_in, uint64_t *y, uint64_t *res)
47 {
48 	uint64_t R = { 0xe100000000000000ULL };
49 	struct aes_block z = { 0, 0 };
50 	struct aes_block v;
51 	uint64_t x;
52 	int i, j;
53 
54 	v.a = ntohll(y[0]);
55 	v.b = ntohll(y[1]);
56 
57 	for (j = 0; j < 2; j++) {
58 		x = ntohll(x_in[j]);
59 		for (i = 0; i < 64; i++, x <<= 1) {
60 			if (x & 0x8000000000000000ULL) {
61 				z.a ^= v.a;
62 				z.b ^= v.b;
63 			}
64 			if (v.b & 1ULL) {
65 				v.b = (v.a << 63)|(v.b >> 1);
66 				v.a = (v.a >> 1) ^ R;
67 			} else {
68 				v.b = (v.a << 63)|(v.b >> 1);
69 				v.a = v.a >> 1;
70 			}
71 		}
72 	}
73 	res[0] = htonll(z.a);
74 	res[1] = htonll(z.b);
75 }
76 
77 #define	GHASH(c, d, t) \
78 	xor_block((uint8_t *)(d), (uint8_t *)(c)->gcm_ghash); \
79 	gcm_mul((uint64_t *)(c)->gcm_ghash, (c)->gcm_H, (uint64_t *)(t));
80 
81 /*
82  * Encrypt multiple blocks of data in GCM mode.  Decrypt for GCM mode
83  * is done in another function.
84  */
85 int
86 gcm_mode_encrypt_contiguous_blocks(gcm_ctx_t *ctx, char *data, size_t length,
87     crypto_data_t *out, size_t block_size,
88     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
89     void (*copy_block)(uint8_t *, uint8_t *),
90     void (*xor_block)(uint8_t *, uint8_t *))
91 {
92 	size_t remainder = length;
93 	size_t need;
94 	uint8_t *datap = (uint8_t *)data;
95 	uint8_t *blockp;
96 	uint8_t *lastp;
97 	void *iov_or_mp;
98 	offset_t offset;
99 	uint8_t *out_data_1;
100 	uint8_t *out_data_2;
101 	size_t out_data_1_len;
102 	uint64_t counter;
103 	uint64_t counter_mask = ntohll(0x00000000ffffffffULL);
104 
105 	if (length + ctx->gcm_remainder_len < block_size) {
106 		/* accumulate bytes here and return */
107 		bcopy(datap,
108 		    (uint8_t *)ctx->gcm_remainder + ctx->gcm_remainder_len,
109 		    length);
110 		ctx->gcm_remainder_len += length;
111 		ctx->gcm_copy_to = datap;
112 		return (CRYPTO_SUCCESS);
113 	}
114 
115 	lastp = (uint8_t *)ctx->gcm_cb;
116 	if (out != NULL)
117 		crypto_init_ptrs(out, &iov_or_mp, &offset);
118 
119 	do {
120 		/* Unprocessed data from last call. */
121 		if (ctx->gcm_remainder_len > 0) {
122 			need = block_size - ctx->gcm_remainder_len;
123 
124 			if (need > remainder)
125 				return (CRYPTO_DATA_LEN_RANGE);
126 
127 			bcopy(datap, &((uint8_t *)ctx->gcm_remainder)
128 			    [ctx->gcm_remainder_len], need);
129 
130 			blockp = (uint8_t *)ctx->gcm_remainder;
131 		} else {
132 			blockp = datap;
133 		}
134 
135 		/*
136 		 * Increment counter. Counter bits are confined
137 		 * to the bottom 32 bits of the counter block.
138 		 */
139 		counter = ntohll(ctx->gcm_cb[1] & counter_mask);
140 		counter = htonll(counter + 1);
141 		counter &= counter_mask;
142 		ctx->gcm_cb[1] = (ctx->gcm_cb[1] & ~counter_mask) | counter;
143 
144 		encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_cb,
145 		    (uint8_t *)ctx->gcm_tmp);
146 		xor_block(blockp, (uint8_t *)ctx->gcm_tmp);
147 
148 		lastp = (uint8_t *)ctx->gcm_tmp;
149 
150 		ctx->gcm_processed_data_len += block_size;
151 
152 		if (out == NULL) {
153 			if (ctx->gcm_remainder_len > 0) {
154 				bcopy(blockp, ctx->gcm_copy_to,
155 				    ctx->gcm_remainder_len);
156 				bcopy(blockp + ctx->gcm_remainder_len, datap,
157 				    need);
158 			}
159 		} else {
160 			crypto_get_ptrs(out, &iov_or_mp, &offset, &out_data_1,
161 			    &out_data_1_len, &out_data_2, block_size);
162 
163 			/* copy block to where it belongs */
164 			if (out_data_1_len == block_size) {
165 				copy_block(lastp, out_data_1);
166 			} else {
167 				bcopy(lastp, out_data_1, out_data_1_len);
168 				if (out_data_2 != NULL) {
169 					bcopy(lastp + out_data_1_len,
170 					    out_data_2,
171 					    block_size - out_data_1_len);
172 				}
173 			}
174 			/* update offset */
175 			out->cd_offset += block_size;
176 		}
177 
178 		/* add ciphertext to the hash */
179 		GHASH(ctx, ctx->gcm_tmp, ctx->gcm_ghash);
180 
181 		/* Update pointer to next block of data to be processed. */
182 		if (ctx->gcm_remainder_len != 0) {
183 			datap += need;
184 			ctx->gcm_remainder_len = 0;
185 		} else {
186 			datap += block_size;
187 		}
188 
189 		remainder = (size_t)&data[length] - (size_t)datap;
190 
191 		/* Incomplete last block. */
192 		if (remainder > 0 && remainder < block_size) {
193 			bcopy(datap, ctx->gcm_remainder, remainder);
194 			ctx->gcm_remainder_len = remainder;
195 			ctx->gcm_copy_to = datap;
196 			goto out;
197 		}
198 		ctx->gcm_copy_to = NULL;
199 
200 	} while (remainder > 0);
201 out:
202 	return (CRYPTO_SUCCESS);
203 }
204 
205 /* ARGSUSED */
206 int
207 gcm_encrypt_final(gcm_ctx_t *ctx, crypto_data_t *out, size_t block_size,
208     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
209     void (*copy_block)(uint8_t *, uint8_t *),
210     void (*xor_block)(uint8_t *, uint8_t *))
211 {
212 	uint64_t counter_mask = ntohll(0x00000000ffffffffULL);
213 	uint8_t *ghash, *macp;
214 	int i, rv;
215 
216 	if (out->cd_length <
217 	    (ctx->gcm_remainder_len + ctx->gcm_tag_len)) {
218 		return (CRYPTO_DATA_LEN_RANGE);
219 	}
220 
221 	ghash = (uint8_t *)ctx->gcm_ghash;
222 
223 	if (ctx->gcm_remainder_len > 0) {
224 		uint64_t counter;
225 		uint8_t *tmpp = (uint8_t *)ctx->gcm_tmp;
226 
227 		/*
228 		 * Here is where we deal with data that is not a
229 		 * multiple of the block size.
230 		 */
231 
232 		/*
233 		 * Increment counter.
234 		 */
235 		counter = ntohll(ctx->gcm_cb[1] & counter_mask);
236 		counter = htonll(counter + 1);
237 		counter &= counter_mask;
238 		ctx->gcm_cb[1] = (ctx->gcm_cb[1] & ~counter_mask) | counter;
239 
240 		encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_cb,
241 		    (uint8_t *)ctx->gcm_tmp);
242 
243 		macp = (uint8_t *)ctx->gcm_remainder;
244 		bzero(macp + ctx->gcm_remainder_len,
245 		    block_size - ctx->gcm_remainder_len);
246 
247 		/* XOR with counter block */
248 		for (i = 0; i < ctx->gcm_remainder_len; i++) {
249 			macp[i] ^= tmpp[i];
250 		}
251 
252 		/* add ciphertext to the hash */
253 		GHASH(ctx, macp, ghash);
254 
255 		ctx->gcm_processed_data_len += ctx->gcm_remainder_len;
256 	}
257 
258 	ctx->gcm_len_a_len_c[1] = htonll(ctx->gcm_processed_data_len << 3);
259 	GHASH(ctx, ctx->gcm_len_a_len_c, ghash);
260 	encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_J0,
261 	    (uint8_t *)ctx->gcm_J0);
262 	xor_block((uint8_t *)ctx->gcm_J0, ghash);
263 
264 	if (ctx->gcm_remainder_len > 0) {
265 		rv = crypto_put_output_data(macp, out, ctx->gcm_remainder_len);
266 		if (rv != CRYPTO_SUCCESS)
267 			return (rv);
268 	}
269 	out->cd_offset += ctx->gcm_remainder_len;
270 	ctx->gcm_remainder_len = 0;
271 	rv = crypto_put_output_data(ghash, out, ctx->gcm_tag_len);
272 	if (rv != CRYPTO_SUCCESS)
273 		return (rv);
274 	out->cd_offset += ctx->gcm_tag_len;
275 
276 	return (CRYPTO_SUCCESS);
277 }
278 
279 /*
280  * This will only deal with decrypting the last block of the input that
281  * might not be a multiple of block length.
282  */
283 static void
284 gcm_decrypt_incomplete_block(gcm_ctx_t *ctx, size_t block_size, size_t index,
285     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
286     void (*xor_block)(uint8_t *, uint8_t *))
287 {
288 	uint8_t *datap, *outp, *counterp;
289 	uint64_t counter;
290 	uint64_t counter_mask = ntohll(0x00000000ffffffffULL);
291 	int i;
292 
293 	/*
294 	 * Increment counter.
295 	 * Counter bits are confined to the bottom 32 bits
296 	 */
297 	counter = ntohll(ctx->gcm_cb[1] & counter_mask);
298 	counter = htonll(counter + 1);
299 	counter &= counter_mask;
300 	ctx->gcm_cb[1] = (ctx->gcm_cb[1] & ~counter_mask) | counter;
301 
302 	datap = (uint8_t *)ctx->gcm_remainder;
303 	outp = &((ctx->gcm_pt_buf)[index]);
304 	counterp = (uint8_t *)ctx->gcm_tmp;
305 
306 	/* authentication tag */
307 	bzero((uint8_t *)ctx->gcm_tmp, block_size);
308 	bcopy(datap, (uint8_t *)ctx->gcm_tmp, ctx->gcm_remainder_len);
309 
310 	/* add ciphertext to the hash */
311 	GHASH(ctx, ctx->gcm_tmp, ctx->gcm_ghash);
312 
313 	/* decrypt remaining ciphertext */
314 	encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_cb, counterp);
315 
316 	/* XOR with counter block */
317 	for (i = 0; i < ctx->gcm_remainder_len; i++) {
318 		outp[i] = datap[i] ^ counterp[i];
319 	}
320 }
321 
322 /* ARGSUSED */
323 int
324 gcm_mode_decrypt_contiguous_blocks(gcm_ctx_t *ctx, char *data, size_t length,
325     crypto_data_t *out, size_t block_size,
326     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
327     void (*copy_block)(uint8_t *, uint8_t *),
328     void (*xor_block)(uint8_t *, uint8_t *))
329 {
330 	size_t new_len;
331 	uint8_t *new;
332 
333 	/*
334 	 * Copy contiguous ciphertext input blocks to plaintext buffer.
335 	 * Ciphertext will be decrypted in the final.
336 	 */
337 	if (length > 0) {
338 		new_len = ctx->gcm_pt_buf_len + length;
339 #ifdef _KERNEL
340 		new = kmem_alloc(new_len, ctx->gcm_kmflag);
341 		bcopy(ctx->gcm_pt_buf, new, ctx->gcm_pt_buf_len);
342 		kmem_free(ctx->gcm_pt_buf, ctx->gcm_pt_buf_len);
343 #else
344 		new = malloc(new_len);
345 		bcopy(ctx->gcm_pt_buf, new, ctx->gcm_pt_buf_len);
346 		free(ctx->gcm_pt_buf);
347 #endif
348 		if (new == NULL)
349 			return (CRYPTO_HOST_MEMORY);
350 
351 		ctx->gcm_pt_buf = new;
352 		ctx->gcm_pt_buf_len = new_len;
353 		bcopy(data, &ctx->gcm_pt_buf[ctx->gcm_processed_data_len],
354 		    length);
355 		ctx->gcm_processed_data_len += length;
356 	}
357 
358 	ctx->gcm_remainder_len = 0;
359 	return (CRYPTO_SUCCESS);
360 }
361 
362 int
363 gcm_decrypt_final(gcm_ctx_t *ctx, crypto_data_t *out, size_t block_size,
364     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
365     void (*xor_block)(uint8_t *, uint8_t *))
366 {
367 	size_t pt_len;
368 	size_t remainder;
369 	uint8_t *ghash;
370 	uint8_t *blockp;
371 	uint8_t *cbp;
372 	uint64_t counter;
373 	uint64_t counter_mask = ntohll(0x00000000ffffffffULL);
374 	int processed = 0, rv;
375 
376 	ASSERT(ctx->gcm_processed_data_len == ctx->gcm_pt_buf_len);
377 
378 	pt_len = ctx->gcm_processed_data_len - ctx->gcm_tag_len;
379 	ghash = (uint8_t *)ctx->gcm_ghash;
380 	blockp = ctx->gcm_pt_buf;
381 	remainder = pt_len;
382 	while (remainder > 0) {
383 		/* add ciphertext to the hash */
384 		GHASH(ctx, blockp, ghash);
385 
386 		/*
387 		 * Increment counter.
388 		 * Counter bits are confined to the bottom 32 bits
389 		 */
390 		counter = ntohll(ctx->gcm_cb[1] & counter_mask);
391 		counter = htonll(counter + 1);
392 		counter &= counter_mask;
393 		ctx->gcm_cb[1] = (ctx->gcm_cb[1] & ~counter_mask) | counter;
394 
395 		cbp = (uint8_t *)ctx->gcm_tmp;
396 		encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_cb, cbp);
397 
398 		/* XOR with ciphertext */
399 		xor_block(cbp, blockp);
400 
401 		processed += block_size;
402 		blockp += block_size;
403 		remainder -= block_size;
404 
405 		/* Incomplete last block */
406 		if (remainder > 0 && remainder < block_size) {
407 			bcopy(blockp, ctx->gcm_remainder, remainder);
408 			ctx->gcm_remainder_len = remainder;
409 			/*
410 			 * not expecting anymore ciphertext, just
411 			 * compute plaintext for the remaining input
412 			 */
413 			gcm_decrypt_incomplete_block(ctx, block_size,
414 			    processed, encrypt_block, xor_block);
415 			ctx->gcm_remainder_len = 0;
416 			goto out;
417 		}
418 	}
419 out:
420 	ctx->gcm_len_a_len_c[1] = htonll(pt_len << 3);
421 	GHASH(ctx, ctx->gcm_len_a_len_c, ghash);
422 	encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_J0,
423 	    (uint8_t *)ctx->gcm_J0);
424 	xor_block((uint8_t *)ctx->gcm_J0, ghash);
425 
426 	/* compare the input authentication tag with what we calculated */
427 	if (bcmp(&ctx->gcm_pt_buf[pt_len], ghash, ctx->gcm_tag_len)) {
428 		/* They don't match */
429 		return (CRYPTO_INVALID_MAC);
430 	} else {
431 		rv = crypto_put_output_data(ctx->gcm_pt_buf, out, pt_len);
432 		if (rv != CRYPTO_SUCCESS)
433 			return (rv);
434 		out->cd_offset += pt_len;
435 	}
436 	return (CRYPTO_SUCCESS);
437 }
438 
439 static int
440 gcm_validate_args(CK_AES_GCM_PARAMS *gcm_param)
441 {
442 	size_t tag_len;
443 
444 	/*
445 	 * Check the length of the authentication tag (in bits).
446 	 */
447 	tag_len = gcm_param->ulTagBits;
448 	switch (tag_len) {
449 	case 32:
450 	case 64:
451 	case 96:
452 	case 104:
453 	case 112:
454 	case 120:
455 	case 128:
456 		break;
457 	default:
458 		return (CRYPTO_MECHANISM_PARAM_INVALID);
459 	}
460 
461 	if (gcm_param->ulIvLen == 0)
462 		return (CRYPTO_MECHANISM_PARAM_INVALID);
463 
464 	return (CRYPTO_SUCCESS);
465 }
466 
467 static void
468 gcm_format_initial_blocks(uchar_t *iv, ulong_t iv_len,
469     gcm_ctx_t *ctx, size_t block_size,
470     void (*copy_block)(uint8_t *, uint8_t *),
471     void (*xor_block)(uint8_t *, uint8_t *))
472 {
473 	uint8_t *cb;
474 	ulong_t remainder = iv_len;
475 	ulong_t processed = 0;
476 	uint8_t *datap, *ghash;
477 	uint64_t len_a_len_c[2];
478 
479 	ghash = (uint8_t *)ctx->gcm_ghash;
480 	cb = (uint8_t *)ctx->gcm_cb;
481 	if (iv_len == 12) {
482 		bcopy(iv, cb, 12);
483 		cb[12] = 0;
484 		cb[13] = 0;
485 		cb[14] = 0;
486 		cb[15] = 1;
487 		/* J0 will be used again in the final */
488 		copy_block(cb, (uint8_t *)ctx->gcm_J0);
489 	} else {
490 		/* GHASH the IV */
491 		do {
492 			if (remainder < block_size) {
493 				bzero(cb, block_size);
494 				bcopy(&(iv[processed]), cb, remainder);
495 				datap = (uint8_t *)cb;
496 				remainder = 0;
497 			} else {
498 				datap = (uint8_t *)(&(iv[processed]));
499 				processed += block_size;
500 				remainder -= block_size;
501 			}
502 			GHASH(ctx, datap, ghash);
503 		} while (remainder > 0);
504 
505 		len_a_len_c[0] = 0;
506 		len_a_len_c[1] = htonll(iv_len << 3);
507 		GHASH(ctx, len_a_len_c, ctx->gcm_J0);
508 
509 		/* J0 will be used again in the final */
510 		copy_block((uint8_t *)ctx->gcm_J0, (uint8_t *)cb);
511 	}
512 }
513 
514 /*
515  * The following function is called at encrypt or decrypt init time
516  * for AES GCM mode.
517  */
518 int
519 gcm_init(gcm_ctx_t *ctx, unsigned char *iv, size_t iv_len,
520     unsigned char *auth_data, size_t auth_data_len, size_t block_size,
521     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
522     void (*copy_block)(uint8_t *, uint8_t *),
523     void (*xor_block)(uint8_t *, uint8_t *))
524 {
525 	uint8_t *ghash, *datap, *authp;
526 	size_t remainder, processed;
527 
528 	/* encrypt zero block to get subkey H */
529 	bzero(ctx->gcm_H, sizeof (ctx->gcm_H));
530 	encrypt_block(ctx->gcm_keysched, (uint8_t *)ctx->gcm_H,
531 	    (uint8_t *)ctx->gcm_H);
532 
533 	gcm_format_initial_blocks(iv, iv_len, ctx, block_size,
534 	    copy_block, xor_block);
535 
536 	authp = (uint8_t *)ctx->gcm_tmp;
537 	ghash = (uint8_t *)ctx->gcm_ghash;
538 	bzero(authp, block_size);
539 	bzero(ghash, block_size);
540 
541 	processed = 0;
542 	remainder = auth_data_len;
543 	do {
544 		if (remainder < block_size) {
545 			/*
546 			 * There's not a block full of data, pad rest of
547 			 * buffer with zero
548 			 */
549 			bzero(authp, block_size);
550 			bcopy(&(auth_data[processed]), authp, remainder);
551 			datap = (uint8_t *)authp;
552 			remainder = 0;
553 		} else {
554 			datap = (uint8_t *)(&(auth_data[processed]));
555 			processed += block_size;
556 			remainder -= block_size;
557 		}
558 
559 		/* add auth data to the hash */
560 		GHASH(ctx, datap, ghash);
561 
562 	} while (remainder > 0);
563 
564 	return (CRYPTO_SUCCESS);
565 }
566 
567 int
568 gcm_init_ctx(gcm_ctx_t *gcm_ctx, char *param, size_t block_size,
569     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
570     void (*copy_block)(uint8_t *, uint8_t *),
571     void (*xor_block)(uint8_t *, uint8_t *))
572 {
573 	int rv;
574 	CK_AES_GCM_PARAMS *gcm_param;
575 
576 	if (param != NULL) {
577 		gcm_param = (CK_AES_GCM_PARAMS *)param;
578 
579 		if ((rv = gcm_validate_args(gcm_param)) != 0) {
580 			return (rv);
581 		}
582 
583 		gcm_ctx->gcm_tag_len = gcm_param->ulTagBits;
584 		gcm_ctx->gcm_tag_len >>= 3;
585 		gcm_ctx->gcm_processed_data_len = 0;
586 
587 		/* these values are in bits */
588 		gcm_ctx->gcm_len_a_len_c[0] = htonll(gcm_param->ulAADLen << 3);
589 
590 		rv = CRYPTO_SUCCESS;
591 		gcm_ctx->gcm_flags |= GCM_MODE;
592 	} else {
593 		rv = CRYPTO_MECHANISM_PARAM_INVALID;
594 		goto out;
595 	}
596 
597 	if (gcm_init(gcm_ctx, gcm_param->pIv, gcm_param->ulIvLen,
598 	    gcm_param->pAAD, gcm_param->ulAADLen, block_size,
599 	    encrypt_block, copy_block, xor_block) != 0) {
600 		rv = CRYPTO_MECHANISM_PARAM_INVALID;
601 	}
602 out:
603 	return (rv);
604 }
605 
606 int
607 gmac_init_ctx(gcm_ctx_t *gcm_ctx, char *param, size_t block_size,
608     int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
609     void (*copy_block)(uint8_t *, uint8_t *),
610     void (*xor_block)(uint8_t *, uint8_t *))
611 {
612 	int rv;
613 	CK_AES_GMAC_PARAMS *gmac_param;
614 
615 	if (param != NULL) {
616 		gmac_param = (CK_AES_GMAC_PARAMS *)param;
617 
618 		gcm_ctx->gcm_tag_len = CRYPTO_BITS2BYTES(AES_GMAC_TAG_BITS);
619 		gcm_ctx->gcm_processed_data_len = 0;
620 
621 		/* these values are in bits */
622 		gcm_ctx->gcm_len_a_len_c[0] = htonll(gmac_param->ulAADLen << 3);
623 
624 		rv = CRYPTO_SUCCESS;
625 		gcm_ctx->gcm_flags |= GMAC_MODE;
626 	} else {
627 		rv = CRYPTO_MECHANISM_PARAM_INVALID;
628 		goto out;
629 	}
630 
631 	if (gcm_init(gcm_ctx, gmac_param->pIv, AES_GMAC_IV_LEN,
632 	    gmac_param->pAAD, gmac_param->ulAADLen, block_size,
633 	    encrypt_block, copy_block, xor_block) != 0) {
634 		rv = CRYPTO_MECHANISM_PARAM_INVALID;
635 	}
636 out:
637 	return (rv);
638 }
639 
640 void *
641 gcm_alloc_ctx(int kmflag)
642 {
643 	gcm_ctx_t *gcm_ctx;
644 
645 #ifdef _KERNEL
646 	if ((gcm_ctx = kmem_zalloc(sizeof (gcm_ctx_t), kmflag)) == NULL)
647 #else
648 	if ((gcm_ctx = calloc(1, sizeof (gcm_ctx_t))) == NULL)
649 #endif
650 		return (NULL);
651 
652 	gcm_ctx->gcm_flags = GCM_MODE;
653 	return (gcm_ctx);
654 }
655 
656 void *
657 gmac_alloc_ctx(int kmflag)
658 {
659 	gcm_ctx_t *gcm_ctx;
660 
661 #ifdef _KERNEL
662 	if ((gcm_ctx = kmem_zalloc(sizeof (gcm_ctx_t), kmflag)) == NULL)
663 #else
664 	if ((gcm_ctx = calloc(1, sizeof (gcm_ctx_t))) == NULL)
665 #endif
666 		return (NULL);
667 
668 	gcm_ctx->gcm_flags = GMAC_MODE;
669 	return (gcm_ctx);
670 }
671 
672 void
673 gcm_set_kmflag(gcm_ctx_t *ctx, int kmflag)
674 {
675 	ctx->gcm_kmflag = kmflag;
676 }
677