593 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Linear symmetric key cipher operations.4 *5 * Generic encrypt/decrypt wrapper for ciphers.6 *7 * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>8 */9 10#include <linux/cryptouser.h>11#include <linux/err.h>12#include <linux/export.h>13#include <linux/kernel.h>14#include <linux/seq_file.h>15#include <linux/slab.h>16#include <linux/string.h>17#include <net/netlink.h>18#include "skcipher.h"19 20static inline struct crypto_lskcipher *__crypto_lskcipher_cast(21 struct crypto_tfm *tfm)22{23 return container_of(tfm, struct crypto_lskcipher, base);24}25 26static inline struct lskcipher_alg *__crypto_lskcipher_alg(27 struct crypto_alg *alg)28{29 return container_of(alg, struct lskcipher_alg, co.base);30}31 32static int lskcipher_setkey_unaligned(struct crypto_lskcipher *tfm,33 const u8 *key, unsigned int keylen)34{35 unsigned long alignmask = crypto_lskcipher_alignmask(tfm);36 struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm);37 u8 *buffer, *alignbuffer;38 unsigned long absize;39 int ret;40 41 absize = keylen + alignmask;42 buffer = kmalloc(absize, GFP_ATOMIC);43 if (!buffer)44 return -ENOMEM;45 46 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);47 memcpy(alignbuffer, key, keylen);48 ret = cipher->setkey(tfm, alignbuffer, keylen);49 kfree_sensitive(buffer);50 return ret;51}52 53int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm, const u8 *key,54 unsigned int keylen)55{56 unsigned long alignmask = crypto_lskcipher_alignmask(tfm);57 struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm);58 59 if (keylen < cipher->co.min_keysize || keylen > cipher->co.max_keysize)60 return -EINVAL;61 62 if ((unsigned long)key & alignmask)63 return lskcipher_setkey_unaligned(tfm, key, keylen);64 else65 return cipher->setkey(tfm, key, keylen);66}67EXPORT_SYMBOL_GPL(crypto_lskcipher_setkey);68 69static int crypto_lskcipher_crypt_unaligned(70 struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned len,71 u8 *iv, int (*crypt)(struct crypto_lskcipher *tfm, const u8 *src,72 u8 *dst, unsigned len, u8 *iv, u32 flags))73{74 unsigned statesize = crypto_lskcipher_statesize(tfm);75 unsigned ivsize = crypto_lskcipher_ivsize(tfm);76 unsigned bs = crypto_lskcipher_blocksize(tfm);77 unsigned cs = crypto_lskcipher_chunksize(tfm);78 int err;79 u8 *tiv;80 u8 *p;81 82 BUILD_BUG_ON(MAX_CIPHER_BLOCKSIZE > PAGE_SIZE ||83 MAX_CIPHER_ALIGNMASK >= PAGE_SIZE);84 85 tiv = kmalloc(PAGE_SIZE, GFP_ATOMIC);86 if (!tiv)87 return -ENOMEM;88 89 memcpy(tiv, iv, ivsize + statesize);90 91 p = kmalloc(PAGE_SIZE, GFP_ATOMIC);92 err = -ENOMEM;93 if (!p)94 goto out;95 96 while (len >= bs) {97 unsigned chunk = min((unsigned)PAGE_SIZE, len);98 int err;99 100 if (chunk > cs)101 chunk &= ~(cs - 1);102 103 memcpy(p, src, chunk);104 err = crypt(tfm, p, p, chunk, tiv, CRYPTO_LSKCIPHER_FLAG_FINAL);105 if (err)106 goto out;107 108 memcpy(dst, p, chunk);109 src += chunk;110 dst += chunk;111 len -= chunk;112 }113 114 err = len ? -EINVAL : 0;115 116out:117 memcpy(iv, tiv, ivsize + statesize);118 kfree_sensitive(p);119 kfree_sensitive(tiv);120 return err;121}122 123static int crypto_lskcipher_crypt(struct crypto_lskcipher *tfm, const u8 *src,124 u8 *dst, unsigned len, u8 *iv,125 int (*crypt)(struct crypto_lskcipher *tfm,126 const u8 *src, u8 *dst,127 unsigned len, u8 *iv,128 u32 flags))129{130 unsigned long alignmask = crypto_lskcipher_alignmask(tfm);131 132 if (((unsigned long)src | (unsigned long)dst | (unsigned long)iv) &133 alignmask)134 return crypto_lskcipher_crypt_unaligned(tfm, src, dst, len, iv,135 crypt);136 137 return crypt(tfm, src, dst, len, iv, CRYPTO_LSKCIPHER_FLAG_FINAL);138}139 140int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,141 u8 *dst, unsigned len, u8 *iv)142{143 struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);144 145 return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->encrypt);146}147EXPORT_SYMBOL_GPL(crypto_lskcipher_encrypt);148 149int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,150 u8 *dst, unsigned len, u8 *iv)151{152 struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);153 154 return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->decrypt);155}156EXPORT_SYMBOL_GPL(crypto_lskcipher_decrypt);157 158static int crypto_lskcipher_crypt_sg(struct skcipher_request *req,159 int (*crypt)(struct crypto_lskcipher *tfm,160 const u8 *src, u8 *dst,161 unsigned len, u8 *ivs,162 u32 flags))163{164 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);165 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);166 u8 *ivs = skcipher_request_ctx(req);167 struct crypto_lskcipher *tfm = *ctx;168 struct skcipher_walk walk;169 unsigned ivsize;170 u32 flags;171 int err;172 173 ivsize = crypto_lskcipher_ivsize(tfm);174 ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(skcipher) + 1);175 memcpy(ivs, req->iv, ivsize);176 177 flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP;178 179 if (req->base.flags & CRYPTO_SKCIPHER_REQ_CONT)180 flags |= CRYPTO_LSKCIPHER_FLAG_CONT;181 182 if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL))183 flags |= CRYPTO_LSKCIPHER_FLAG_FINAL;184 185 err = skcipher_walk_virt(&walk, req, false);186 187 while (walk.nbytes) {188 err = crypt(tfm, walk.src.virt.addr, walk.dst.virt.addr,189 walk.nbytes, ivs,190 flags & ~(walk.nbytes == walk.total ?191 0 : CRYPTO_LSKCIPHER_FLAG_FINAL));192 err = skcipher_walk_done(&walk, err);193 flags |= CRYPTO_LSKCIPHER_FLAG_CONT;194 }195 196 memcpy(req->iv, ivs, ivsize);197 198 return err;199}200 201int crypto_lskcipher_encrypt_sg(struct skcipher_request *req)202{203 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);204 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);205 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx);206 207 return crypto_lskcipher_crypt_sg(req, alg->encrypt);208}209 210int crypto_lskcipher_decrypt_sg(struct skcipher_request *req)211{212 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);213 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);214 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx);215 216 return crypto_lskcipher_crypt_sg(req, alg->decrypt);217}218 219static void crypto_lskcipher_exit_tfm(struct crypto_tfm *tfm)220{221 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm);222 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher);223 224 alg->exit(skcipher);225}226 227static int crypto_lskcipher_init_tfm(struct crypto_tfm *tfm)228{229 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm);230 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher);231 232 if (alg->exit)233 skcipher->base.exit = crypto_lskcipher_exit_tfm;234 235 if (alg->init)236 return alg->init(skcipher);237 238 return 0;239}240 241static void crypto_lskcipher_free_instance(struct crypto_instance *inst)242{243 struct lskcipher_instance *skcipher =244 container_of(inst, struct lskcipher_instance, s.base);245 246 skcipher->free(skcipher);247}248 249static void __maybe_unused crypto_lskcipher_show(250 struct seq_file *m, struct crypto_alg *alg)251{252 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);253 254 seq_printf(m, "type : lskcipher\n");255 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);256 seq_printf(m, "min keysize : %u\n", skcipher->co.min_keysize);257 seq_printf(m, "max keysize : %u\n", skcipher->co.max_keysize);258 seq_printf(m, "ivsize : %u\n", skcipher->co.ivsize);259 seq_printf(m, "chunksize : %u\n", skcipher->co.chunksize);260 seq_printf(m, "statesize : %u\n", skcipher->co.statesize);261}262 263static int __maybe_unused crypto_lskcipher_report(264 struct sk_buff *skb, struct crypto_alg *alg)265{266 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);267 struct crypto_report_blkcipher rblkcipher;268 269 memset(&rblkcipher, 0, sizeof(rblkcipher));270 271 strscpy(rblkcipher.type, "lskcipher", sizeof(rblkcipher.type));272 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));273 274 rblkcipher.blocksize = alg->cra_blocksize;275 rblkcipher.min_keysize = skcipher->co.min_keysize;276 rblkcipher.max_keysize = skcipher->co.max_keysize;277 rblkcipher.ivsize = skcipher->co.ivsize;278 279 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,280 sizeof(rblkcipher), &rblkcipher);281}282 283static const struct crypto_type crypto_lskcipher_type = {284 .extsize = crypto_alg_extsize,285 .init_tfm = crypto_lskcipher_init_tfm,286 .free = crypto_lskcipher_free_instance,287#ifdef CONFIG_PROC_FS288 .show = crypto_lskcipher_show,289#endif290#if IS_ENABLED(CONFIG_CRYPTO_USER)291 .report = crypto_lskcipher_report,292#endif293 .maskclear = ~CRYPTO_ALG_TYPE_MASK,294 .maskset = CRYPTO_ALG_TYPE_MASK,295 .type = CRYPTO_ALG_TYPE_LSKCIPHER,296 .tfmsize = offsetof(struct crypto_lskcipher, base),297};298 299static void crypto_lskcipher_exit_tfm_sg(struct crypto_tfm *tfm)300{301 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);302 303 crypto_free_lskcipher(*ctx);304}305 306int crypto_init_lskcipher_ops_sg(struct crypto_tfm *tfm)307{308 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);309 struct crypto_alg *calg = tfm->__crt_alg;310 struct crypto_lskcipher *skcipher;311 312 if (!crypto_mod_get(calg))313 return -EAGAIN;314 315 skcipher = crypto_create_tfm(calg, &crypto_lskcipher_type);316 if (IS_ERR(skcipher)) {317 crypto_mod_put(calg);318 return PTR_ERR(skcipher);319 }320 321 *ctx = skcipher;322 tfm->exit = crypto_lskcipher_exit_tfm_sg;323 324 return 0;325}326 327int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn,328 struct crypto_instance *inst,329 const char *name, u32 type, u32 mask)330{331 spawn->base.frontend = &crypto_lskcipher_type;332 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);333}334EXPORT_SYMBOL_GPL(crypto_grab_lskcipher);335 336struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,337 u32 type, u32 mask)338{339 return crypto_alloc_tfm(alg_name, &crypto_lskcipher_type, type, mask);340}341EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher);342 343static int lskcipher_prepare_alg(struct lskcipher_alg *alg)344{345 struct crypto_alg *base = &alg->co.base;346 int err;347 348 err = skcipher_prepare_alg_common(&alg->co);349 if (err)350 return err;351 352 if (alg->co.chunksize & (alg->co.chunksize - 1))353 return -EINVAL;354 355 base->cra_type = &crypto_lskcipher_type;356 base->cra_flags |= CRYPTO_ALG_TYPE_LSKCIPHER;357 358 return 0;359}360 361int crypto_register_lskcipher(struct lskcipher_alg *alg)362{363 struct crypto_alg *base = &alg->co.base;364 int err;365 366 err = lskcipher_prepare_alg(alg);367 if (err)368 return err;369 370 return crypto_register_alg(base);371}372EXPORT_SYMBOL_GPL(crypto_register_lskcipher);373 374void crypto_unregister_lskcipher(struct lskcipher_alg *alg)375{376 crypto_unregister_alg(&alg->co.base);377}378EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher);379 380int crypto_register_lskciphers(struct lskcipher_alg *algs, int count)381{382 int i, ret;383 384 for (i = 0; i < count; i++) {385 ret = crypto_register_lskcipher(&algs[i]);386 if (ret)387 goto err;388 }389 390 return 0;391 392err:393 for (--i; i >= 0; --i)394 crypto_unregister_lskcipher(&algs[i]);395 396 return ret;397}398EXPORT_SYMBOL_GPL(crypto_register_lskciphers);399 400void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count)401{402 int i;403 404 for (i = count - 1; i >= 0; --i)405 crypto_unregister_lskcipher(&algs[i]);406}407EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers);408 409int lskcipher_register_instance(struct crypto_template *tmpl,410 struct lskcipher_instance *inst)411{412 int err;413 414 if (WARN_ON(!inst->free))415 return -EINVAL;416 417 err = lskcipher_prepare_alg(&inst->alg);418 if (err)419 return err;420 421 return crypto_register_instance(tmpl, lskcipher_crypto_instance(inst));422}423EXPORT_SYMBOL_GPL(lskcipher_register_instance);424 425static int lskcipher_setkey_simple(struct crypto_lskcipher *tfm, const u8 *key,426 unsigned int keylen)427{428 struct crypto_lskcipher *cipher = lskcipher_cipher_simple(tfm);429 430 crypto_lskcipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);431 crypto_lskcipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &432 CRYPTO_TFM_REQ_MASK);433 return crypto_lskcipher_setkey(cipher, key, keylen);434}435 436static int lskcipher_init_tfm_simple(struct crypto_lskcipher *tfm)437{438 struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);439 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);440 struct crypto_lskcipher_spawn *spawn;441 struct crypto_lskcipher *cipher;442 443 spawn = lskcipher_instance_ctx(inst);444 cipher = crypto_spawn_lskcipher(spawn);445 if (IS_ERR(cipher))446 return PTR_ERR(cipher);447 448 *ctx = cipher;449 return 0;450}451 452static void lskcipher_exit_tfm_simple(struct crypto_lskcipher *tfm)453{454 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);455 456 crypto_free_lskcipher(*ctx);457}458 459static void lskcipher_free_instance_simple(struct lskcipher_instance *inst)460{461 crypto_drop_lskcipher(lskcipher_instance_ctx(inst));462 kfree(inst);463}464 465/**466 * lskcipher_alloc_instance_simple - allocate instance of simple block cipher467 *468 * Allocate an lskcipher_instance for a simple block cipher mode of operation,469 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn,470 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,471 * alignmask, and priority are set from the underlying cipher but can be472 * overridden if needed. The tfm context defaults to473 * struct crypto_lskcipher *, and default ->setkey(), ->init(), and474 * ->exit() methods are installed.475 *476 * @tmpl: the template being instantiated477 * @tb: the template parameters478 *479 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still480 * needs to register the instance.481 */482struct lskcipher_instance *lskcipher_alloc_instance_simple(483 struct crypto_template *tmpl, struct rtattr **tb)484{485 u32 mask;486 struct lskcipher_instance *inst;487 struct crypto_lskcipher_spawn *spawn;488 char ecb_name[CRYPTO_MAX_ALG_NAME];489 struct lskcipher_alg *cipher_alg;490 const char *cipher_name;491 int err;492 493 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);494 if (err)495 return ERR_PTR(err);496 497 cipher_name = crypto_attr_alg_name(tb[1]);498 if (IS_ERR(cipher_name))499 return ERR_CAST(cipher_name);500 501 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);502 if (!inst)503 return ERR_PTR(-ENOMEM);504 505 spawn = lskcipher_instance_ctx(inst);506 err = crypto_grab_lskcipher(spawn,507 lskcipher_crypto_instance(inst),508 cipher_name, 0, mask);509 510 ecb_name[0] = 0;511 if (err == -ENOENT && !!memcmp(tmpl->name, "ecb", 4)) {512 err = -ENAMETOOLONG;513 if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",514 cipher_name) >= CRYPTO_MAX_ALG_NAME)515 goto err_free_inst;516 517 err = crypto_grab_lskcipher(spawn,518 lskcipher_crypto_instance(inst),519 ecb_name, 0, mask);520 }521 522 if (err)523 goto err_free_inst;524 525 cipher_alg = crypto_lskcipher_spawn_alg(spawn);526 527 err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,528 &cipher_alg->co.base);529 if (err)530 goto err_free_inst;531 532 if (ecb_name[0]) {533 int len;534 535 err = -EINVAL;536 len = strscpy(ecb_name, &cipher_alg->co.base.cra_name[4],537 sizeof(ecb_name));538 if (len < 2)539 goto err_free_inst;540 541 if (ecb_name[len - 1] != ')')542 goto err_free_inst;543 544 ecb_name[len - 1] = 0;545 546 err = -ENAMETOOLONG;547 if (snprintf(inst->alg.co.base.cra_name, CRYPTO_MAX_ALG_NAME,548 "%s(%s)", tmpl->name, ecb_name) >=549 CRYPTO_MAX_ALG_NAME)550 goto err_free_inst;551 552 if (strcmp(ecb_name, cipher_name) &&553 snprintf(inst->alg.co.base.cra_driver_name,554 CRYPTO_MAX_ALG_NAME,555 "%s(%s)", tmpl->name, cipher_name) >=556 CRYPTO_MAX_ALG_NAME)557 goto err_free_inst;558 } else {559 /* Don't allow nesting. */560 err = -ELOOP;561 if ((cipher_alg->co.base.cra_flags & CRYPTO_ALG_INSTANCE))562 goto err_free_inst;563 }564 565 err = -EINVAL;566 if (cipher_alg->co.ivsize)567 goto err_free_inst;568 569 inst->free = lskcipher_free_instance_simple;570 571 /* Default algorithm properties, can be overridden */572 inst->alg.co.base.cra_blocksize = cipher_alg->co.base.cra_blocksize;573 inst->alg.co.base.cra_alignmask = cipher_alg->co.base.cra_alignmask;574 inst->alg.co.base.cra_priority = cipher_alg->co.base.cra_priority;575 inst->alg.co.min_keysize = cipher_alg->co.min_keysize;576 inst->alg.co.max_keysize = cipher_alg->co.max_keysize;577 inst->alg.co.ivsize = cipher_alg->co.base.cra_blocksize;578 inst->alg.co.statesize = cipher_alg->co.statesize;579 580 /* Use struct crypto_lskcipher * by default, can be overridden */581 inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_lskcipher *);582 inst->alg.setkey = lskcipher_setkey_simple;583 inst->alg.init = lskcipher_init_tfm_simple;584 inst->alg.exit = lskcipher_exit_tfm_simple;585 586 return inst;587 588err_free_inst:589 lskcipher_free_instance_simple(inst);590 return ERR_PTR(err);591}592EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple);593