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0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * GCM: Galois/Counter Mode.
0004  *
0005  * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
0006  */
0007 
0008 #include <crypto/gf128mul.h>
0009 #include <crypto/internal/aead.h>
0010 #include <crypto/internal/skcipher.h>
0011 #include <crypto/internal/hash.h>
0012 #include <crypto/null.h>
0013 #include <crypto/scatterwalk.h>
0014 #include <crypto/gcm.h>
0015 #include <crypto/hash.h>
0016 #include <linux/err.h>
0017 #include <linux/init.h>
0018 #include <linux/kernel.h>
0019 #include <linux/module.h>
0020 #include <linux/slab.h>
0021 
0022 struct gcm_instance_ctx {
0023     struct crypto_skcipher_spawn ctr;
0024     struct crypto_ahash_spawn ghash;
0025 };
0026 
0027 struct crypto_gcm_ctx {
0028     struct crypto_skcipher *ctr;
0029     struct crypto_ahash *ghash;
0030 };
0031 
0032 struct crypto_rfc4106_ctx {
0033     struct crypto_aead *child;
0034     u8 nonce[4];
0035 };
0036 
0037 struct crypto_rfc4106_req_ctx {
0038     struct scatterlist src[3];
0039     struct scatterlist dst[3];
0040     struct aead_request subreq;
0041 };
0042 
0043 struct crypto_rfc4543_instance_ctx {
0044     struct crypto_aead_spawn aead;
0045 };
0046 
0047 struct crypto_rfc4543_ctx {
0048     struct crypto_aead *child;
0049     struct crypto_sync_skcipher *null;
0050     u8 nonce[4];
0051 };
0052 
0053 struct crypto_rfc4543_req_ctx {
0054     struct aead_request subreq;
0055 };
0056 
0057 struct crypto_gcm_ghash_ctx {
0058     unsigned int cryptlen;
0059     struct scatterlist *src;
0060     int (*complete)(struct aead_request *req, u32 flags);
0061 };
0062 
0063 struct crypto_gcm_req_priv_ctx {
0064     u8 iv[16];
0065     u8 auth_tag[16];
0066     u8 iauth_tag[16];
0067     struct scatterlist src[3];
0068     struct scatterlist dst[3];
0069     struct scatterlist sg;
0070     struct crypto_gcm_ghash_ctx ghash_ctx;
0071     union {
0072         struct ahash_request ahreq;
0073         struct skcipher_request skreq;
0074     } u;
0075 };
0076 
0077 static struct {
0078     u8 buf[16];
0079     struct scatterlist sg;
0080 } *gcm_zeroes;
0081 
0082 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);
0083 
0084 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
0085     struct aead_request *req)
0086 {
0087     unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
0088 
0089     return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
0090 }
0091 
0092 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
0093                  unsigned int keylen)
0094 {
0095     struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
0096     struct crypto_ahash *ghash = ctx->ghash;
0097     struct crypto_skcipher *ctr = ctx->ctr;
0098     struct {
0099         be128 hash;
0100         u8 iv[16];
0101 
0102         struct crypto_wait wait;
0103 
0104         struct scatterlist sg[1];
0105         struct skcipher_request req;
0106     } *data;
0107     int err;
0108 
0109     crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
0110     crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
0111                        CRYPTO_TFM_REQ_MASK);
0112     err = crypto_skcipher_setkey(ctr, key, keylen);
0113     if (err)
0114         return err;
0115 
0116     data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
0117                GFP_KERNEL);
0118     if (!data)
0119         return -ENOMEM;
0120 
0121     crypto_init_wait(&data->wait);
0122     sg_init_one(data->sg, &data->hash, sizeof(data->hash));
0123     skcipher_request_set_tfm(&data->req, ctr);
0124     skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
0125                           CRYPTO_TFM_REQ_MAY_BACKLOG,
0126                       crypto_req_done,
0127                       &data->wait);
0128     skcipher_request_set_crypt(&data->req, data->sg, data->sg,
0129                    sizeof(data->hash), data->iv);
0130 
0131     err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
0132                             &data->wait);
0133 
0134     if (err)
0135         goto out;
0136 
0137     crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
0138     crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
0139                    CRYPTO_TFM_REQ_MASK);
0140     err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
0141 out:
0142     kfree_sensitive(data);
0143     return err;
0144 }
0145 
0146 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
0147                   unsigned int authsize)
0148 {
0149     return crypto_gcm_check_authsize(authsize);
0150 }
0151 
0152 static void crypto_gcm_init_common(struct aead_request *req)
0153 {
0154     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0155     __be32 counter = cpu_to_be32(1);
0156     struct scatterlist *sg;
0157 
0158     memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
0159     memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE);
0160     memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4);
0161 
0162     sg_init_table(pctx->src, 3);
0163     sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
0164     sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
0165     if (sg != pctx->src + 1)
0166         sg_chain(pctx->src, 2, sg);
0167 
0168     if (req->src != req->dst) {
0169         sg_init_table(pctx->dst, 3);
0170         sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
0171         sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
0172         if (sg != pctx->dst + 1)
0173             sg_chain(pctx->dst, 2, sg);
0174     }
0175 }
0176 
0177 static void crypto_gcm_init_crypt(struct aead_request *req,
0178                   unsigned int cryptlen)
0179 {
0180     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0181     struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
0182     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0183     struct skcipher_request *skreq = &pctx->u.skreq;
0184     struct scatterlist *dst;
0185 
0186     dst = req->src == req->dst ? pctx->src : pctx->dst;
0187 
0188     skcipher_request_set_tfm(skreq, ctx->ctr);
0189     skcipher_request_set_crypt(skreq, pctx->src, dst,
0190                      cryptlen + sizeof(pctx->auth_tag),
0191                      pctx->iv);
0192 }
0193 
0194 static inline unsigned int gcm_remain(unsigned int len)
0195 {
0196     len &= 0xfU;
0197     return len ? 16 - len : 0;
0198 }
0199 
0200 static void gcm_hash_len_done(struct crypto_async_request *areq, int err);
0201 
0202 static int gcm_hash_update(struct aead_request *req,
0203                crypto_completion_t compl,
0204                struct scatterlist *src,
0205                unsigned int len, u32 flags)
0206 {
0207     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0208     struct ahash_request *ahreq = &pctx->u.ahreq;
0209 
0210     ahash_request_set_callback(ahreq, flags, compl, req);
0211     ahash_request_set_crypt(ahreq, src, NULL, len);
0212 
0213     return crypto_ahash_update(ahreq);
0214 }
0215 
0216 static int gcm_hash_remain(struct aead_request *req,
0217                unsigned int remain,
0218                crypto_completion_t compl, u32 flags)
0219 {
0220     return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
0221 }
0222 
0223 static int gcm_hash_len(struct aead_request *req, u32 flags)
0224 {
0225     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0226     struct ahash_request *ahreq = &pctx->u.ahreq;
0227     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0228     be128 lengths;
0229 
0230     lengths.a = cpu_to_be64(req->assoclen * 8);
0231     lengths.b = cpu_to_be64(gctx->cryptlen * 8);
0232     memcpy(pctx->iauth_tag, &lengths, 16);
0233     sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
0234     ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
0235     ahash_request_set_crypt(ahreq, &pctx->sg,
0236                 pctx->iauth_tag, sizeof(lengths));
0237 
0238     return crypto_ahash_finup(ahreq);
0239 }
0240 
0241 static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
0242 {
0243     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0244     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0245 
0246     return gctx->complete(req, flags);
0247 }
0248 
0249 static void gcm_hash_len_done(struct crypto_async_request *areq, int err)
0250 {
0251     struct aead_request *req = areq->data;
0252 
0253     if (err)
0254         goto out;
0255 
0256     err = gcm_hash_len_continue(req, 0);
0257     if (err == -EINPROGRESS)
0258         return;
0259 
0260 out:
0261     aead_request_complete(req, err);
0262 }
0263 
0264 static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
0265 {
0266     return gcm_hash_len(req, flags) ?:
0267            gcm_hash_len_continue(req, flags);
0268 }
0269 
0270 static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
0271                        int err)
0272 {
0273     struct aead_request *req = areq->data;
0274 
0275     if (err)
0276         goto out;
0277 
0278     err = gcm_hash_crypt_remain_continue(req, 0);
0279     if (err == -EINPROGRESS)
0280         return;
0281 
0282 out:
0283     aead_request_complete(req, err);
0284 }
0285 
0286 static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
0287 {
0288     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0289     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0290     unsigned int remain;
0291 
0292     remain = gcm_remain(gctx->cryptlen);
0293     if (remain)
0294         return gcm_hash_remain(req, remain,
0295                        gcm_hash_crypt_remain_done, flags) ?:
0296                gcm_hash_crypt_remain_continue(req, flags);
0297 
0298     return gcm_hash_crypt_remain_continue(req, flags);
0299 }
0300 
0301 static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err)
0302 {
0303     struct aead_request *req = areq->data;
0304 
0305     if (err)
0306         goto out;
0307 
0308     err = gcm_hash_crypt_continue(req, 0);
0309     if (err == -EINPROGRESS)
0310         return;
0311 
0312 out:
0313     aead_request_complete(req, err);
0314 }
0315 
0316 static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
0317 {
0318     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0319     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0320 
0321     if (gctx->cryptlen)
0322         return gcm_hash_update(req, gcm_hash_crypt_done,
0323                        gctx->src, gctx->cryptlen, flags) ?:
0324                gcm_hash_crypt_continue(req, flags);
0325 
0326     return gcm_hash_crypt_remain_continue(req, flags);
0327 }
0328 
0329 static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
0330                        int err)
0331 {
0332     struct aead_request *req = areq->data;
0333 
0334     if (err)
0335         goto out;
0336 
0337     err = gcm_hash_assoc_remain_continue(req, 0);
0338     if (err == -EINPROGRESS)
0339         return;
0340 
0341 out:
0342     aead_request_complete(req, err);
0343 }
0344 
0345 static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
0346 {
0347     unsigned int remain;
0348 
0349     remain = gcm_remain(req->assoclen);
0350     if (remain)
0351         return gcm_hash_remain(req, remain,
0352                        gcm_hash_assoc_remain_done, flags) ?:
0353                gcm_hash_assoc_remain_continue(req, flags);
0354 
0355     return gcm_hash_assoc_remain_continue(req, flags);
0356 }
0357 
0358 static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err)
0359 {
0360     struct aead_request *req = areq->data;
0361 
0362     if (err)
0363         goto out;
0364 
0365     err = gcm_hash_assoc_continue(req, 0);
0366     if (err == -EINPROGRESS)
0367         return;
0368 
0369 out:
0370     aead_request_complete(req, err);
0371 }
0372 
0373 static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
0374 {
0375     if (req->assoclen)
0376         return gcm_hash_update(req, gcm_hash_assoc_done,
0377                        req->src, req->assoclen, flags) ?:
0378                gcm_hash_assoc_continue(req, flags);
0379 
0380     return gcm_hash_assoc_remain_continue(req, flags);
0381 }
0382 
0383 static void gcm_hash_init_done(struct crypto_async_request *areq, int err)
0384 {
0385     struct aead_request *req = areq->data;
0386 
0387     if (err)
0388         goto out;
0389 
0390     err = gcm_hash_init_continue(req, 0);
0391     if (err == -EINPROGRESS)
0392         return;
0393 
0394 out:
0395     aead_request_complete(req, err);
0396 }
0397 
0398 static int gcm_hash(struct aead_request *req, u32 flags)
0399 {
0400     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0401     struct ahash_request *ahreq = &pctx->u.ahreq;
0402     struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
0403 
0404     ahash_request_set_tfm(ahreq, ctx->ghash);
0405 
0406     ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
0407     return crypto_ahash_init(ahreq) ?:
0408            gcm_hash_init_continue(req, flags);
0409 }
0410 
0411 static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
0412 {
0413     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0414     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0415     u8 *auth_tag = pctx->auth_tag;
0416 
0417     crypto_xor(auth_tag, pctx->iauth_tag, 16);
0418     scatterwalk_map_and_copy(auth_tag, req->dst,
0419                  req->assoclen + req->cryptlen,
0420                  crypto_aead_authsize(aead), 1);
0421     return 0;
0422 }
0423 
0424 static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
0425 {
0426     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0427     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0428 
0429     gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
0430     gctx->cryptlen = req->cryptlen;
0431     gctx->complete = gcm_enc_copy_hash;
0432 
0433     return gcm_hash(req, flags);
0434 }
0435 
0436 static void gcm_encrypt_done(struct crypto_async_request *areq, int err)
0437 {
0438     struct aead_request *req = areq->data;
0439 
0440     if (err)
0441         goto out;
0442 
0443     err = gcm_encrypt_continue(req, 0);
0444     if (err == -EINPROGRESS)
0445         return;
0446 
0447 out:
0448     aead_request_complete(req, err);
0449 }
0450 
0451 static int crypto_gcm_encrypt(struct aead_request *req)
0452 {
0453     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0454     struct skcipher_request *skreq = &pctx->u.skreq;
0455     u32 flags = aead_request_flags(req);
0456 
0457     crypto_gcm_init_common(req);
0458     crypto_gcm_init_crypt(req, req->cryptlen);
0459     skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);
0460 
0461     return crypto_skcipher_encrypt(skreq) ?:
0462            gcm_encrypt_continue(req, flags);
0463 }
0464 
0465 static int crypto_gcm_verify(struct aead_request *req)
0466 {
0467     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0468     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0469     u8 *auth_tag = pctx->auth_tag;
0470     u8 *iauth_tag = pctx->iauth_tag;
0471     unsigned int authsize = crypto_aead_authsize(aead);
0472     unsigned int cryptlen = req->cryptlen - authsize;
0473 
0474     crypto_xor(auth_tag, iauth_tag, 16);
0475     scatterwalk_map_and_copy(iauth_tag, req->src,
0476                  req->assoclen + cryptlen, authsize, 0);
0477     return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
0478 }
0479 
0480 static void gcm_decrypt_done(struct crypto_async_request *areq, int err)
0481 {
0482     struct aead_request *req = areq->data;
0483 
0484     if (!err)
0485         err = crypto_gcm_verify(req);
0486 
0487     aead_request_complete(req, err);
0488 }
0489 
0490 static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
0491 {
0492     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0493     struct skcipher_request *skreq = &pctx->u.skreq;
0494     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0495 
0496     crypto_gcm_init_crypt(req, gctx->cryptlen);
0497     skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
0498     return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
0499 }
0500 
0501 static int crypto_gcm_decrypt(struct aead_request *req)
0502 {
0503     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0504     struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
0505     struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
0506     unsigned int authsize = crypto_aead_authsize(aead);
0507     unsigned int cryptlen = req->cryptlen;
0508     u32 flags = aead_request_flags(req);
0509 
0510     cryptlen -= authsize;
0511 
0512     crypto_gcm_init_common(req);
0513 
0514     gctx->src = sg_next(pctx->src);
0515     gctx->cryptlen = cryptlen;
0516     gctx->complete = gcm_dec_hash_continue;
0517 
0518     return gcm_hash(req, flags);
0519 }
0520 
0521 static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
0522 {
0523     struct aead_instance *inst = aead_alg_instance(tfm);
0524     struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
0525     struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
0526     struct crypto_skcipher *ctr;
0527     struct crypto_ahash *ghash;
0528     unsigned long align;
0529     int err;
0530 
0531     ghash = crypto_spawn_ahash(&ictx->ghash);
0532     if (IS_ERR(ghash))
0533         return PTR_ERR(ghash);
0534 
0535     ctr = crypto_spawn_skcipher(&ictx->ctr);
0536     err = PTR_ERR(ctr);
0537     if (IS_ERR(ctr))
0538         goto err_free_hash;
0539 
0540     ctx->ctr = ctr;
0541     ctx->ghash = ghash;
0542 
0543     align = crypto_aead_alignmask(tfm);
0544     align &= ~(crypto_tfm_ctx_alignment() - 1);
0545     crypto_aead_set_reqsize(tfm,
0546         align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
0547         max(sizeof(struct skcipher_request) +
0548             crypto_skcipher_reqsize(ctr),
0549             sizeof(struct ahash_request) +
0550             crypto_ahash_reqsize(ghash)));
0551 
0552     return 0;
0553 
0554 err_free_hash:
0555     crypto_free_ahash(ghash);
0556     return err;
0557 }
0558 
0559 static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
0560 {
0561     struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
0562 
0563     crypto_free_ahash(ctx->ghash);
0564     crypto_free_skcipher(ctx->ctr);
0565 }
0566 
0567 static void crypto_gcm_free(struct aead_instance *inst)
0568 {
0569     struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);
0570 
0571     crypto_drop_skcipher(&ctx->ctr);
0572     crypto_drop_ahash(&ctx->ghash);
0573     kfree(inst);
0574 }
0575 
0576 static int crypto_gcm_create_common(struct crypto_template *tmpl,
0577                     struct rtattr **tb,
0578                     const char *ctr_name,
0579                     const char *ghash_name)
0580 {
0581     u32 mask;
0582     struct aead_instance *inst;
0583     struct gcm_instance_ctx *ctx;
0584     struct skcipher_alg *ctr;
0585     struct hash_alg_common *ghash;
0586     int err;
0587 
0588     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
0589     if (err)
0590         return err;
0591 
0592     inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
0593     if (!inst)
0594         return -ENOMEM;
0595     ctx = aead_instance_ctx(inst);
0596 
0597     err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
0598                 ghash_name, 0, mask);
0599     if (err)
0600         goto err_free_inst;
0601     ghash = crypto_spawn_ahash_alg(&ctx->ghash);
0602 
0603     err = -EINVAL;
0604     if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
0605         ghash->digestsize != 16)
0606         goto err_free_inst;
0607 
0608     err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
0609                    ctr_name, 0, mask);
0610     if (err)
0611         goto err_free_inst;
0612     ctr = crypto_spawn_skcipher_alg(&ctx->ctr);
0613 
0614     /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
0615     err = -EINVAL;
0616     if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
0617         crypto_skcipher_alg_ivsize(ctr) != 16 ||
0618         ctr->base.cra_blocksize != 1)
0619         goto err_free_inst;
0620 
0621     err = -ENAMETOOLONG;
0622     if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
0623              "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
0624         goto err_free_inst;
0625 
0626     if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
0627              "gcm_base(%s,%s)", ctr->base.cra_driver_name,
0628              ghash->base.cra_driver_name) >=
0629         CRYPTO_MAX_ALG_NAME)
0630         goto err_free_inst;
0631 
0632     inst->alg.base.cra_priority = (ghash->base.cra_priority +
0633                        ctr->base.cra_priority) / 2;
0634     inst->alg.base.cra_blocksize = 1;
0635     inst->alg.base.cra_alignmask = ghash->base.cra_alignmask |
0636                        ctr->base.cra_alignmask;
0637     inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
0638     inst->alg.ivsize = GCM_AES_IV_SIZE;
0639     inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
0640     inst->alg.maxauthsize = 16;
0641     inst->alg.init = crypto_gcm_init_tfm;
0642     inst->alg.exit = crypto_gcm_exit_tfm;
0643     inst->alg.setkey = crypto_gcm_setkey;
0644     inst->alg.setauthsize = crypto_gcm_setauthsize;
0645     inst->alg.encrypt = crypto_gcm_encrypt;
0646     inst->alg.decrypt = crypto_gcm_decrypt;
0647 
0648     inst->free = crypto_gcm_free;
0649 
0650     err = aead_register_instance(tmpl, inst);
0651     if (err) {
0652 err_free_inst:
0653         crypto_gcm_free(inst);
0654     }
0655     return err;
0656 }
0657 
0658 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
0659 {
0660     const char *cipher_name;
0661     char ctr_name[CRYPTO_MAX_ALG_NAME];
0662 
0663     cipher_name = crypto_attr_alg_name(tb[1]);
0664     if (IS_ERR(cipher_name))
0665         return PTR_ERR(cipher_name);
0666 
0667     if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
0668         CRYPTO_MAX_ALG_NAME)
0669         return -ENAMETOOLONG;
0670 
0671     return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
0672 }
0673 
0674 static int crypto_gcm_base_create(struct crypto_template *tmpl,
0675                   struct rtattr **tb)
0676 {
0677     const char *ctr_name;
0678     const char *ghash_name;
0679 
0680     ctr_name = crypto_attr_alg_name(tb[1]);
0681     if (IS_ERR(ctr_name))
0682         return PTR_ERR(ctr_name);
0683 
0684     ghash_name = crypto_attr_alg_name(tb[2]);
0685     if (IS_ERR(ghash_name))
0686         return PTR_ERR(ghash_name);
0687 
0688     return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
0689 }
0690 
0691 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
0692                  unsigned int keylen)
0693 {
0694     struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
0695     struct crypto_aead *child = ctx->child;
0696 
0697     if (keylen < 4)
0698         return -EINVAL;
0699 
0700     keylen -= 4;
0701     memcpy(ctx->nonce, key + keylen, 4);
0702 
0703     crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
0704     crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
0705                      CRYPTO_TFM_REQ_MASK);
0706     return crypto_aead_setkey(child, key, keylen);
0707 }
0708 
0709 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
0710                       unsigned int authsize)
0711 {
0712     struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
0713     int err;
0714 
0715     err = crypto_rfc4106_check_authsize(authsize);
0716     if (err)
0717         return err;
0718 
0719     return crypto_aead_setauthsize(ctx->child, authsize);
0720 }
0721 
0722 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
0723 {
0724     struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
0725     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0726     struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
0727     struct aead_request *subreq = &rctx->subreq;
0728     struct crypto_aead *child = ctx->child;
0729     struct scatterlist *sg;
0730     u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
0731                crypto_aead_alignmask(child) + 1);
0732 
0733     scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
0734 
0735     memcpy(iv, ctx->nonce, 4);
0736     memcpy(iv + 4, req->iv, 8);
0737 
0738     sg_init_table(rctx->src, 3);
0739     sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
0740     sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
0741     if (sg != rctx->src + 1)
0742         sg_chain(rctx->src, 2, sg);
0743 
0744     if (req->src != req->dst) {
0745         sg_init_table(rctx->dst, 3);
0746         sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
0747         sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
0748         if (sg != rctx->dst + 1)
0749             sg_chain(rctx->dst, 2, sg);
0750     }
0751 
0752     aead_request_set_tfm(subreq, child);
0753     aead_request_set_callback(subreq, req->base.flags, req->base.complete,
0754                   req->base.data);
0755     aead_request_set_crypt(subreq, rctx->src,
0756                    req->src == req->dst ? rctx->src : rctx->dst,
0757                    req->cryptlen, iv);
0758     aead_request_set_ad(subreq, req->assoclen - 8);
0759 
0760     return subreq;
0761 }
0762 
0763 static int crypto_rfc4106_encrypt(struct aead_request *req)
0764 {
0765     int err;
0766 
0767     err = crypto_ipsec_check_assoclen(req->assoclen);
0768     if (err)
0769         return err;
0770 
0771     req = crypto_rfc4106_crypt(req);
0772 
0773     return crypto_aead_encrypt(req);
0774 }
0775 
0776 static int crypto_rfc4106_decrypt(struct aead_request *req)
0777 {
0778     int err;
0779 
0780     err = crypto_ipsec_check_assoclen(req->assoclen);
0781     if (err)
0782         return err;
0783 
0784     req = crypto_rfc4106_crypt(req);
0785 
0786     return crypto_aead_decrypt(req);
0787 }
0788 
0789 static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
0790 {
0791     struct aead_instance *inst = aead_alg_instance(tfm);
0792     struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
0793     struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
0794     struct crypto_aead *aead;
0795     unsigned long align;
0796 
0797     aead = crypto_spawn_aead(spawn);
0798     if (IS_ERR(aead))
0799         return PTR_ERR(aead);
0800 
0801     ctx->child = aead;
0802 
0803     align = crypto_aead_alignmask(aead);
0804     align &= ~(crypto_tfm_ctx_alignment() - 1);
0805     crypto_aead_set_reqsize(
0806         tfm,
0807         sizeof(struct crypto_rfc4106_req_ctx) +
0808         ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
0809         align + 24);
0810 
0811     return 0;
0812 }
0813 
0814 static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
0815 {
0816     struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
0817 
0818     crypto_free_aead(ctx->child);
0819 }
0820 
0821 static void crypto_rfc4106_free(struct aead_instance *inst)
0822 {
0823     crypto_drop_aead(aead_instance_ctx(inst));
0824     kfree(inst);
0825 }
0826 
0827 static int crypto_rfc4106_create(struct crypto_template *tmpl,
0828                  struct rtattr **tb)
0829 {
0830     u32 mask;
0831     struct aead_instance *inst;
0832     struct crypto_aead_spawn *spawn;
0833     struct aead_alg *alg;
0834     int err;
0835 
0836     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
0837     if (err)
0838         return err;
0839 
0840     inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
0841     if (!inst)
0842         return -ENOMEM;
0843 
0844     spawn = aead_instance_ctx(inst);
0845     err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
0846                    crypto_attr_alg_name(tb[1]), 0, mask);
0847     if (err)
0848         goto err_free_inst;
0849 
0850     alg = crypto_spawn_aead_alg(spawn);
0851 
0852     err = -EINVAL;
0853 
0854     /* Underlying IV size must be 12. */
0855     if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
0856         goto err_free_inst;
0857 
0858     /* Not a stream cipher? */
0859     if (alg->base.cra_blocksize != 1)
0860         goto err_free_inst;
0861 
0862     err = -ENAMETOOLONG;
0863     if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
0864              "rfc4106(%s)", alg->base.cra_name) >=
0865         CRYPTO_MAX_ALG_NAME ||
0866         snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
0867              "rfc4106(%s)", alg->base.cra_driver_name) >=
0868         CRYPTO_MAX_ALG_NAME)
0869         goto err_free_inst;
0870 
0871     inst->alg.base.cra_priority = alg->base.cra_priority;
0872     inst->alg.base.cra_blocksize = 1;
0873     inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
0874 
0875     inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
0876 
0877     inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
0878     inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
0879     inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
0880 
0881     inst->alg.init = crypto_rfc4106_init_tfm;
0882     inst->alg.exit = crypto_rfc4106_exit_tfm;
0883 
0884     inst->alg.setkey = crypto_rfc4106_setkey;
0885     inst->alg.setauthsize = crypto_rfc4106_setauthsize;
0886     inst->alg.encrypt = crypto_rfc4106_encrypt;
0887     inst->alg.decrypt = crypto_rfc4106_decrypt;
0888 
0889     inst->free = crypto_rfc4106_free;
0890 
0891     err = aead_register_instance(tmpl, inst);
0892     if (err) {
0893 err_free_inst:
0894         crypto_rfc4106_free(inst);
0895     }
0896     return err;
0897 }
0898 
0899 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
0900                  unsigned int keylen)
0901 {
0902     struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
0903     struct crypto_aead *child = ctx->child;
0904 
0905     if (keylen < 4)
0906         return -EINVAL;
0907 
0908     keylen -= 4;
0909     memcpy(ctx->nonce, key + keylen, 4);
0910 
0911     crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
0912     crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
0913                      CRYPTO_TFM_REQ_MASK);
0914     return crypto_aead_setkey(child, key, keylen);
0915 }
0916 
0917 static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
0918                       unsigned int authsize)
0919 {
0920     struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
0921 
0922     if (authsize != 16)
0923         return -EINVAL;
0924 
0925     return crypto_aead_setauthsize(ctx->child, authsize);
0926 }
0927 
0928 static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
0929 {
0930     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0931     struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
0932     struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
0933     struct aead_request *subreq = &rctx->subreq;
0934     unsigned int authsize = crypto_aead_authsize(aead);
0935     u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
0936                crypto_aead_alignmask(ctx->child) + 1);
0937     int err;
0938 
0939     if (req->src != req->dst) {
0940         err = crypto_rfc4543_copy_src_to_dst(req, enc);
0941         if (err)
0942             return err;
0943     }
0944 
0945     memcpy(iv, ctx->nonce, 4);
0946     memcpy(iv + 4, req->iv, 8);
0947 
0948     aead_request_set_tfm(subreq, ctx->child);
0949     aead_request_set_callback(subreq, req->base.flags,
0950                   req->base.complete, req->base.data);
0951     aead_request_set_crypt(subreq, req->src, req->dst,
0952                    enc ? 0 : authsize, iv);
0953     aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
0954                     subreq->cryptlen);
0955 
0956     return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
0957 }
0958 
0959 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
0960 {
0961     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0962     struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
0963     unsigned int authsize = crypto_aead_authsize(aead);
0964     unsigned int nbytes = req->assoclen + req->cryptlen -
0965                   (enc ? 0 : authsize);
0966     SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
0967 
0968     skcipher_request_set_sync_tfm(nreq, ctx->null);
0969     skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
0970     skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);
0971 
0972     return crypto_skcipher_encrypt(nreq);
0973 }
0974 
0975 static int crypto_rfc4543_encrypt(struct aead_request *req)
0976 {
0977     return crypto_ipsec_check_assoclen(req->assoclen) ?:
0978            crypto_rfc4543_crypt(req, true);
0979 }
0980 
0981 static int crypto_rfc4543_decrypt(struct aead_request *req)
0982 {
0983     return crypto_ipsec_check_assoclen(req->assoclen) ?:
0984            crypto_rfc4543_crypt(req, false);
0985 }
0986 
0987 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
0988 {
0989     struct aead_instance *inst = aead_alg_instance(tfm);
0990     struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
0991     struct crypto_aead_spawn *spawn = &ictx->aead;
0992     struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
0993     struct crypto_aead *aead;
0994     struct crypto_sync_skcipher *null;
0995     unsigned long align;
0996     int err = 0;
0997 
0998     aead = crypto_spawn_aead(spawn);
0999     if (IS_ERR(aead))
1000         return PTR_ERR(aead);
1001 
1002     null = crypto_get_default_null_skcipher();
1003     err = PTR_ERR(null);
1004     if (IS_ERR(null))
1005         goto err_free_aead;
1006 
1007     ctx->child = aead;
1008     ctx->null = null;
1009 
1010     align = crypto_aead_alignmask(aead);
1011     align &= ~(crypto_tfm_ctx_alignment() - 1);
1012     crypto_aead_set_reqsize(
1013         tfm,
1014         sizeof(struct crypto_rfc4543_req_ctx) +
1015         ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
1016         align + GCM_AES_IV_SIZE);
1017 
1018     return 0;
1019 
1020 err_free_aead:
1021     crypto_free_aead(aead);
1022     return err;
1023 }
1024 
1025 static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
1026 {
1027     struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
1028 
1029     crypto_free_aead(ctx->child);
1030     crypto_put_default_null_skcipher();
1031 }
1032 
1033 static void crypto_rfc4543_free(struct aead_instance *inst)
1034 {
1035     struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
1036 
1037     crypto_drop_aead(&ctx->aead);
1038 
1039     kfree(inst);
1040 }
1041 
1042 static int crypto_rfc4543_create(struct crypto_template *tmpl,
1043                 struct rtattr **tb)
1044 {
1045     u32 mask;
1046     struct aead_instance *inst;
1047     struct aead_alg *alg;
1048     struct crypto_rfc4543_instance_ctx *ctx;
1049     int err;
1050 
1051     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1052     if (err)
1053         return err;
1054 
1055     inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1056     if (!inst)
1057         return -ENOMEM;
1058 
1059     ctx = aead_instance_ctx(inst);
1060     err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1061                    crypto_attr_alg_name(tb[1]), 0, mask);
1062     if (err)
1063         goto err_free_inst;
1064 
1065     alg = crypto_spawn_aead_alg(&ctx->aead);
1066 
1067     err = -EINVAL;
1068 
1069     /* Underlying IV size must be 12. */
1070     if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1071         goto err_free_inst;
1072 
1073     /* Not a stream cipher? */
1074     if (alg->base.cra_blocksize != 1)
1075         goto err_free_inst;
1076 
1077     err = -ENAMETOOLONG;
1078     if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1079              "rfc4543(%s)", alg->base.cra_name) >=
1080         CRYPTO_MAX_ALG_NAME ||
1081         snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1082              "rfc4543(%s)", alg->base.cra_driver_name) >=
1083         CRYPTO_MAX_ALG_NAME)
1084         goto err_free_inst;
1085 
1086     inst->alg.base.cra_priority = alg->base.cra_priority;
1087     inst->alg.base.cra_blocksize = 1;
1088     inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1089 
1090     inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1091 
1092     inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1093     inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1094     inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1095 
1096     inst->alg.init = crypto_rfc4543_init_tfm;
1097     inst->alg.exit = crypto_rfc4543_exit_tfm;
1098 
1099     inst->alg.setkey = crypto_rfc4543_setkey;
1100     inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1101     inst->alg.encrypt = crypto_rfc4543_encrypt;
1102     inst->alg.decrypt = crypto_rfc4543_decrypt;
1103 
1104     inst->free = crypto_rfc4543_free;
1105 
1106     err = aead_register_instance(tmpl, inst);
1107     if (err) {
1108 err_free_inst:
1109         crypto_rfc4543_free(inst);
1110     }
1111     return err;
1112 }
1113 
1114 static struct crypto_template crypto_gcm_tmpls[] = {
1115     {
1116         .name = "gcm_base",
1117         .create = crypto_gcm_base_create,
1118         .module = THIS_MODULE,
1119     }, {
1120         .name = "gcm",
1121         .create = crypto_gcm_create,
1122         .module = THIS_MODULE,
1123     }, {
1124         .name = "rfc4106",
1125         .create = crypto_rfc4106_create,
1126         .module = THIS_MODULE,
1127     }, {
1128         .name = "rfc4543",
1129         .create = crypto_rfc4543_create,
1130         .module = THIS_MODULE,
1131     },
1132 };
1133 
1134 static int __init crypto_gcm_module_init(void)
1135 {
1136     int err;
1137 
1138     gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1139     if (!gcm_zeroes)
1140         return -ENOMEM;
1141 
1142     sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1143 
1144     err = crypto_register_templates(crypto_gcm_tmpls,
1145                     ARRAY_SIZE(crypto_gcm_tmpls));
1146     if (err)
1147         kfree(gcm_zeroes);
1148 
1149     return err;
1150 }
1151 
1152 static void __exit crypto_gcm_module_exit(void)
1153 {
1154     kfree(gcm_zeroes);
1155     crypto_unregister_templates(crypto_gcm_tmpls,
1156                     ARRAY_SIZE(crypto_gcm_tmpls));
1157 }
1158 
1159 subsys_initcall(crypto_gcm_module_init);
1160 module_exit(crypto_gcm_module_exit);
1161 
1162 MODULE_LICENSE("GPL");
1163 MODULE_DESCRIPTION("Galois/Counter Mode");
1164 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1165 MODULE_ALIAS_CRYPTO("gcm_base");
1166 MODULE_ALIAS_CRYPTO("rfc4106");
1167 MODULE_ALIAS_CRYPTO("rfc4543");
1168 MODULE_ALIAS_CRYPTO("gcm");
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