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0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * CCM: Counter with CBC-MAC
0004  *
0005  * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
0006  */
0007 
0008 #include <crypto/internal/aead.h>
0009 #include <crypto/internal/cipher.h>
0010 #include <crypto/internal/hash.h>
0011 #include <crypto/internal/skcipher.h>
0012 #include <crypto/scatterwalk.h>
0013 #include <linux/err.h>
0014 #include <linux/init.h>
0015 #include <linux/kernel.h>
0016 #include <linux/module.h>
0017 #include <linux/slab.h>
0018 
0019 struct ccm_instance_ctx {
0020     struct crypto_skcipher_spawn ctr;
0021     struct crypto_ahash_spawn mac;
0022 };
0023 
0024 struct crypto_ccm_ctx {
0025     struct crypto_ahash *mac;
0026     struct crypto_skcipher *ctr;
0027 };
0028 
0029 struct crypto_rfc4309_ctx {
0030     struct crypto_aead *child;
0031     u8 nonce[3];
0032 };
0033 
0034 struct crypto_rfc4309_req_ctx {
0035     struct scatterlist src[3];
0036     struct scatterlist dst[3];
0037     struct aead_request subreq;
0038 };
0039 
0040 struct crypto_ccm_req_priv_ctx {
0041     u8 odata[16];
0042     u8 idata[16];
0043     u8 auth_tag[16];
0044     u32 flags;
0045     struct scatterlist src[3];
0046     struct scatterlist dst[3];
0047     union {
0048         struct ahash_request ahreq;
0049         struct skcipher_request skreq;
0050     };
0051 };
0052 
0053 struct cbcmac_tfm_ctx {
0054     struct crypto_cipher *child;
0055 };
0056 
0057 struct cbcmac_desc_ctx {
0058     unsigned int len;
0059 };
0060 
0061 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
0062     struct aead_request *req)
0063 {
0064     unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
0065 
0066     return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
0067 }
0068 
0069 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
0070 {
0071     __be32 data;
0072 
0073     memset(block, 0, csize);
0074     block += csize;
0075 
0076     if (csize >= 4)
0077         csize = 4;
0078     else if (msglen > (1 << (8 * csize)))
0079         return -EOVERFLOW;
0080 
0081     data = cpu_to_be32(msglen);
0082     memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
0083 
0084     return 0;
0085 }
0086 
0087 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
0088                  unsigned int keylen)
0089 {
0090     struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
0091     struct crypto_skcipher *ctr = ctx->ctr;
0092     struct crypto_ahash *mac = ctx->mac;
0093     int err;
0094 
0095     crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
0096     crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
0097                        CRYPTO_TFM_REQ_MASK);
0098     err = crypto_skcipher_setkey(ctr, key, keylen);
0099     if (err)
0100         return err;
0101 
0102     crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
0103     crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
0104                     CRYPTO_TFM_REQ_MASK);
0105     return crypto_ahash_setkey(mac, key, keylen);
0106 }
0107 
0108 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
0109                   unsigned int authsize)
0110 {
0111     switch (authsize) {
0112     case 4:
0113     case 6:
0114     case 8:
0115     case 10:
0116     case 12:
0117     case 14:
0118     case 16:
0119         break;
0120     default:
0121         return -EINVAL;
0122     }
0123 
0124     return 0;
0125 }
0126 
0127 static int format_input(u8 *info, struct aead_request *req,
0128             unsigned int cryptlen)
0129 {
0130     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0131     unsigned int lp = req->iv[0];
0132     unsigned int l = lp + 1;
0133     unsigned int m;
0134 
0135     m = crypto_aead_authsize(aead);
0136 
0137     memcpy(info, req->iv, 16);
0138 
0139     /* format control info per RFC 3610 and
0140      * NIST Special Publication 800-38C
0141      */
0142     *info |= (8 * ((m - 2) / 2));
0143     if (req->assoclen)
0144         *info |= 64;
0145 
0146     return set_msg_len(info + 16 - l, cryptlen, l);
0147 }
0148 
0149 static int format_adata(u8 *adata, unsigned int a)
0150 {
0151     int len = 0;
0152 
0153     /* add control info for associated data
0154      * RFC 3610 and NIST Special Publication 800-38C
0155      */
0156     if (a < 65280) {
0157         *(__be16 *)adata = cpu_to_be16(a);
0158         len = 2;
0159     } else  {
0160         *(__be16 *)adata = cpu_to_be16(0xfffe);
0161         *(__be32 *)&adata[2] = cpu_to_be32(a);
0162         len = 6;
0163     }
0164 
0165     return len;
0166 }
0167 
0168 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
0169                unsigned int cryptlen)
0170 {
0171     struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
0172     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0173     struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
0174     struct ahash_request *ahreq = &pctx->ahreq;
0175     unsigned int assoclen = req->assoclen;
0176     struct scatterlist sg[3];
0177     u8 *odata = pctx->odata;
0178     u8 *idata = pctx->idata;
0179     int ilen, err;
0180 
0181     /* format control data for input */
0182     err = format_input(odata, req, cryptlen);
0183     if (err)
0184         goto out;
0185 
0186     sg_init_table(sg, 3);
0187     sg_set_buf(&sg[0], odata, 16);
0188 
0189     /* format associated data and compute into mac */
0190     if (assoclen) {
0191         ilen = format_adata(idata, assoclen);
0192         sg_set_buf(&sg[1], idata, ilen);
0193         sg_chain(sg, 3, req->src);
0194     } else {
0195         ilen = 0;
0196         sg_chain(sg, 2, req->src);
0197     }
0198 
0199     ahash_request_set_tfm(ahreq, ctx->mac);
0200     ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
0201     ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
0202     err = crypto_ahash_init(ahreq);
0203     if (err)
0204         goto out;
0205     err = crypto_ahash_update(ahreq);
0206     if (err)
0207         goto out;
0208 
0209     /* we need to pad the MAC input to a round multiple of the block size */
0210     ilen = 16 - (assoclen + ilen) % 16;
0211     if (ilen < 16) {
0212         memset(idata, 0, ilen);
0213         sg_init_table(sg, 2);
0214         sg_set_buf(&sg[0], idata, ilen);
0215         if (plain)
0216             sg_chain(sg, 2, plain);
0217         plain = sg;
0218         cryptlen += ilen;
0219     }
0220 
0221     ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
0222     err = crypto_ahash_finup(ahreq);
0223 out:
0224     return err;
0225 }
0226 
0227 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
0228 {
0229     struct aead_request *req = areq->data;
0230     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0231     struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
0232     u8 *odata = pctx->odata;
0233 
0234     if (!err)
0235         scatterwalk_map_and_copy(odata, req->dst,
0236                      req->assoclen + req->cryptlen,
0237                      crypto_aead_authsize(aead), 1);
0238     aead_request_complete(req, err);
0239 }
0240 
0241 static inline int crypto_ccm_check_iv(const u8 *iv)
0242 {
0243     /* 2 <= L <= 8, so 1 <= L' <= 7. */
0244     if (1 > iv[0] || iv[0] > 7)
0245         return -EINVAL;
0246 
0247     return 0;
0248 }
0249 
0250 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
0251 {
0252     struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
0253     struct scatterlist *sg;
0254     u8 *iv = req->iv;
0255     int err;
0256 
0257     err = crypto_ccm_check_iv(iv);
0258     if (err)
0259         return err;
0260 
0261     pctx->flags = aead_request_flags(req);
0262 
0263      /* Note: rfc 3610 and NIST 800-38C require counter of
0264      * zero to encrypt auth tag.
0265      */
0266     memset(iv + 15 - iv[0], 0, iv[0] + 1);
0267 
0268     sg_init_table(pctx->src, 3);
0269     sg_set_buf(pctx->src, tag, 16);
0270     sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
0271     if (sg != pctx->src + 1)
0272         sg_chain(pctx->src, 2, sg);
0273 
0274     if (req->src != req->dst) {
0275         sg_init_table(pctx->dst, 3);
0276         sg_set_buf(pctx->dst, tag, 16);
0277         sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
0278         if (sg != pctx->dst + 1)
0279             sg_chain(pctx->dst, 2, sg);
0280     }
0281 
0282     return 0;
0283 }
0284 
0285 static int crypto_ccm_encrypt(struct aead_request *req)
0286 {
0287     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0288     struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
0289     struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
0290     struct skcipher_request *skreq = &pctx->skreq;
0291     struct scatterlist *dst;
0292     unsigned int cryptlen = req->cryptlen;
0293     u8 *odata = pctx->odata;
0294     u8 *iv = req->iv;
0295     int err;
0296 
0297     err = crypto_ccm_init_crypt(req, odata);
0298     if (err)
0299         return err;
0300 
0301     err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
0302     if (err)
0303         return err;
0304 
0305     dst = pctx->src;
0306     if (req->src != req->dst)
0307         dst = pctx->dst;
0308 
0309     skcipher_request_set_tfm(skreq, ctx->ctr);
0310     skcipher_request_set_callback(skreq, pctx->flags,
0311                       crypto_ccm_encrypt_done, req);
0312     skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
0313     err = crypto_skcipher_encrypt(skreq);
0314     if (err)
0315         return err;
0316 
0317     /* copy authtag to end of dst */
0318     scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
0319                  crypto_aead_authsize(aead), 1);
0320     return err;
0321 }
0322 
0323 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
0324                    int err)
0325 {
0326     struct aead_request *req = areq->data;
0327     struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
0328     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0329     unsigned int authsize = crypto_aead_authsize(aead);
0330     unsigned int cryptlen = req->cryptlen - authsize;
0331     struct scatterlist *dst;
0332 
0333     pctx->flags = 0;
0334 
0335     dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
0336 
0337     if (!err) {
0338         err = crypto_ccm_auth(req, dst, cryptlen);
0339         if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
0340             err = -EBADMSG;
0341     }
0342     aead_request_complete(req, err);
0343 }
0344 
0345 static int crypto_ccm_decrypt(struct aead_request *req)
0346 {
0347     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0348     struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
0349     struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
0350     struct skcipher_request *skreq = &pctx->skreq;
0351     struct scatterlist *dst;
0352     unsigned int authsize = crypto_aead_authsize(aead);
0353     unsigned int cryptlen = req->cryptlen;
0354     u8 *authtag = pctx->auth_tag;
0355     u8 *odata = pctx->odata;
0356     u8 *iv = pctx->idata;
0357     int err;
0358 
0359     cryptlen -= authsize;
0360 
0361     err = crypto_ccm_init_crypt(req, authtag);
0362     if (err)
0363         return err;
0364 
0365     scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
0366                  authsize, 0);
0367 
0368     dst = pctx->src;
0369     if (req->src != req->dst)
0370         dst = pctx->dst;
0371 
0372     memcpy(iv, req->iv, 16);
0373 
0374     skcipher_request_set_tfm(skreq, ctx->ctr);
0375     skcipher_request_set_callback(skreq, pctx->flags,
0376                       crypto_ccm_decrypt_done, req);
0377     skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
0378     err = crypto_skcipher_decrypt(skreq);
0379     if (err)
0380         return err;
0381 
0382     err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
0383     if (err)
0384         return err;
0385 
0386     /* verify */
0387     if (crypto_memneq(authtag, odata, authsize))
0388         return -EBADMSG;
0389 
0390     return err;
0391 }
0392 
0393 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
0394 {
0395     struct aead_instance *inst = aead_alg_instance(tfm);
0396     struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
0397     struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
0398     struct crypto_ahash *mac;
0399     struct crypto_skcipher *ctr;
0400     unsigned long align;
0401     int err;
0402 
0403     mac = crypto_spawn_ahash(&ictx->mac);
0404     if (IS_ERR(mac))
0405         return PTR_ERR(mac);
0406 
0407     ctr = crypto_spawn_skcipher(&ictx->ctr);
0408     err = PTR_ERR(ctr);
0409     if (IS_ERR(ctr))
0410         goto err_free_mac;
0411 
0412     ctx->mac = mac;
0413     ctx->ctr = ctr;
0414 
0415     align = crypto_aead_alignmask(tfm);
0416     align &= ~(crypto_tfm_ctx_alignment() - 1);
0417     crypto_aead_set_reqsize(
0418         tfm,
0419         align + sizeof(struct crypto_ccm_req_priv_ctx) +
0420         max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
0421 
0422     return 0;
0423 
0424 err_free_mac:
0425     crypto_free_ahash(mac);
0426     return err;
0427 }
0428 
0429 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
0430 {
0431     struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
0432 
0433     crypto_free_ahash(ctx->mac);
0434     crypto_free_skcipher(ctx->ctr);
0435 }
0436 
0437 static void crypto_ccm_free(struct aead_instance *inst)
0438 {
0439     struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
0440 
0441     crypto_drop_ahash(&ctx->mac);
0442     crypto_drop_skcipher(&ctx->ctr);
0443     kfree(inst);
0444 }
0445 
0446 static int crypto_ccm_create_common(struct crypto_template *tmpl,
0447                     struct rtattr **tb,
0448                     const char *ctr_name,
0449                     const char *mac_name)
0450 {
0451     u32 mask;
0452     struct aead_instance *inst;
0453     struct ccm_instance_ctx *ictx;
0454     struct skcipher_alg *ctr;
0455     struct hash_alg_common *mac;
0456     int err;
0457 
0458     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
0459     if (err)
0460         return err;
0461 
0462     inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
0463     if (!inst)
0464         return -ENOMEM;
0465     ictx = aead_instance_ctx(inst);
0466 
0467     err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
0468                 mac_name, 0, mask | CRYPTO_ALG_ASYNC);
0469     if (err)
0470         goto err_free_inst;
0471     mac = crypto_spawn_ahash_alg(&ictx->mac);
0472 
0473     err = -EINVAL;
0474     if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
0475         mac->digestsize != 16)
0476         goto err_free_inst;
0477 
0478     err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
0479                    ctr_name, 0, mask);
0480     if (err)
0481         goto err_free_inst;
0482     ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
0483 
0484     /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
0485     err = -EINVAL;
0486     if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
0487         crypto_skcipher_alg_ivsize(ctr) != 16 ||
0488         ctr->base.cra_blocksize != 1)
0489         goto err_free_inst;
0490 
0491     /* ctr and cbcmac must use the same underlying block cipher. */
0492     if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
0493         goto err_free_inst;
0494 
0495     err = -ENAMETOOLONG;
0496     if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
0497              "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
0498         goto err_free_inst;
0499 
0500     if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
0501              "ccm_base(%s,%s)", ctr->base.cra_driver_name,
0502              mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
0503         goto err_free_inst;
0504 
0505     inst->alg.base.cra_priority = (mac->base.cra_priority +
0506                        ctr->base.cra_priority) / 2;
0507     inst->alg.base.cra_blocksize = 1;
0508     inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
0509                        ctr->base.cra_alignmask;
0510     inst->alg.ivsize = 16;
0511     inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
0512     inst->alg.maxauthsize = 16;
0513     inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
0514     inst->alg.init = crypto_ccm_init_tfm;
0515     inst->alg.exit = crypto_ccm_exit_tfm;
0516     inst->alg.setkey = crypto_ccm_setkey;
0517     inst->alg.setauthsize = crypto_ccm_setauthsize;
0518     inst->alg.encrypt = crypto_ccm_encrypt;
0519     inst->alg.decrypt = crypto_ccm_decrypt;
0520 
0521     inst->free = crypto_ccm_free;
0522 
0523     err = aead_register_instance(tmpl, inst);
0524     if (err) {
0525 err_free_inst:
0526         crypto_ccm_free(inst);
0527     }
0528     return err;
0529 }
0530 
0531 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
0532 {
0533     const char *cipher_name;
0534     char ctr_name[CRYPTO_MAX_ALG_NAME];
0535     char mac_name[CRYPTO_MAX_ALG_NAME];
0536 
0537     cipher_name = crypto_attr_alg_name(tb[1]);
0538     if (IS_ERR(cipher_name))
0539         return PTR_ERR(cipher_name);
0540 
0541     if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
0542              cipher_name) >= CRYPTO_MAX_ALG_NAME)
0543         return -ENAMETOOLONG;
0544 
0545     if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
0546              cipher_name) >= CRYPTO_MAX_ALG_NAME)
0547         return -ENAMETOOLONG;
0548 
0549     return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
0550 }
0551 
0552 static int crypto_ccm_base_create(struct crypto_template *tmpl,
0553                   struct rtattr **tb)
0554 {
0555     const char *ctr_name;
0556     const char *mac_name;
0557 
0558     ctr_name = crypto_attr_alg_name(tb[1]);
0559     if (IS_ERR(ctr_name))
0560         return PTR_ERR(ctr_name);
0561 
0562     mac_name = crypto_attr_alg_name(tb[2]);
0563     if (IS_ERR(mac_name))
0564         return PTR_ERR(mac_name);
0565 
0566     return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
0567 }
0568 
0569 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
0570                  unsigned int keylen)
0571 {
0572     struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
0573     struct crypto_aead *child = ctx->child;
0574 
0575     if (keylen < 3)
0576         return -EINVAL;
0577 
0578     keylen -= 3;
0579     memcpy(ctx->nonce, key + keylen, 3);
0580 
0581     crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
0582     crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
0583                      CRYPTO_TFM_REQ_MASK);
0584     return crypto_aead_setkey(child, key, keylen);
0585 }
0586 
0587 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
0588                       unsigned int authsize)
0589 {
0590     struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
0591 
0592     switch (authsize) {
0593     case 8:
0594     case 12:
0595     case 16:
0596         break;
0597     default:
0598         return -EINVAL;
0599     }
0600 
0601     return crypto_aead_setauthsize(ctx->child, authsize);
0602 }
0603 
0604 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
0605 {
0606     struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
0607     struct aead_request *subreq = &rctx->subreq;
0608     struct crypto_aead *aead = crypto_aead_reqtfm(req);
0609     struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
0610     struct crypto_aead *child = ctx->child;
0611     struct scatterlist *sg;
0612     u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
0613                crypto_aead_alignmask(child) + 1);
0614 
0615     /* L' */
0616     iv[0] = 3;
0617 
0618     memcpy(iv + 1, ctx->nonce, 3);
0619     memcpy(iv + 4, req->iv, 8);
0620 
0621     scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
0622 
0623     sg_init_table(rctx->src, 3);
0624     sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
0625     sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
0626     if (sg != rctx->src + 1)
0627         sg_chain(rctx->src, 2, sg);
0628 
0629     if (req->src != req->dst) {
0630         sg_init_table(rctx->dst, 3);
0631         sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
0632         sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
0633         if (sg != rctx->dst + 1)
0634             sg_chain(rctx->dst, 2, sg);
0635     }
0636 
0637     aead_request_set_tfm(subreq, child);
0638     aead_request_set_callback(subreq, req->base.flags, req->base.complete,
0639                   req->base.data);
0640     aead_request_set_crypt(subreq, rctx->src,
0641                    req->src == req->dst ? rctx->src : rctx->dst,
0642                    req->cryptlen, iv);
0643     aead_request_set_ad(subreq, req->assoclen - 8);
0644 
0645     return subreq;
0646 }
0647 
0648 static int crypto_rfc4309_encrypt(struct aead_request *req)
0649 {
0650     if (req->assoclen != 16 && req->assoclen != 20)
0651         return -EINVAL;
0652 
0653     req = crypto_rfc4309_crypt(req);
0654 
0655     return crypto_aead_encrypt(req);
0656 }
0657 
0658 static int crypto_rfc4309_decrypt(struct aead_request *req)
0659 {
0660     if (req->assoclen != 16 && req->assoclen != 20)
0661         return -EINVAL;
0662 
0663     req = crypto_rfc4309_crypt(req);
0664 
0665     return crypto_aead_decrypt(req);
0666 }
0667 
0668 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
0669 {
0670     struct aead_instance *inst = aead_alg_instance(tfm);
0671     struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
0672     struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
0673     struct crypto_aead *aead;
0674     unsigned long align;
0675 
0676     aead = crypto_spawn_aead(spawn);
0677     if (IS_ERR(aead))
0678         return PTR_ERR(aead);
0679 
0680     ctx->child = aead;
0681 
0682     align = crypto_aead_alignmask(aead);
0683     align &= ~(crypto_tfm_ctx_alignment() - 1);
0684     crypto_aead_set_reqsize(
0685         tfm,
0686         sizeof(struct crypto_rfc4309_req_ctx) +
0687         ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
0688         align + 32);
0689 
0690     return 0;
0691 }
0692 
0693 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
0694 {
0695     struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
0696 
0697     crypto_free_aead(ctx->child);
0698 }
0699 
0700 static void crypto_rfc4309_free(struct aead_instance *inst)
0701 {
0702     crypto_drop_aead(aead_instance_ctx(inst));
0703     kfree(inst);
0704 }
0705 
0706 static int crypto_rfc4309_create(struct crypto_template *tmpl,
0707                  struct rtattr **tb)
0708 {
0709     u32 mask;
0710     struct aead_instance *inst;
0711     struct crypto_aead_spawn *spawn;
0712     struct aead_alg *alg;
0713     int err;
0714 
0715     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
0716     if (err)
0717         return err;
0718 
0719     inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
0720     if (!inst)
0721         return -ENOMEM;
0722 
0723     spawn = aead_instance_ctx(inst);
0724     err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
0725                    crypto_attr_alg_name(tb[1]), 0, mask);
0726     if (err)
0727         goto err_free_inst;
0728 
0729     alg = crypto_spawn_aead_alg(spawn);
0730 
0731     err = -EINVAL;
0732 
0733     /* We only support 16-byte blocks. */
0734     if (crypto_aead_alg_ivsize(alg) != 16)
0735         goto err_free_inst;
0736 
0737     /* Not a stream cipher? */
0738     if (alg->base.cra_blocksize != 1)
0739         goto err_free_inst;
0740 
0741     err = -ENAMETOOLONG;
0742     if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
0743              "rfc4309(%s)", alg->base.cra_name) >=
0744         CRYPTO_MAX_ALG_NAME ||
0745         snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
0746              "rfc4309(%s)", alg->base.cra_driver_name) >=
0747         CRYPTO_MAX_ALG_NAME)
0748         goto err_free_inst;
0749 
0750     inst->alg.base.cra_priority = alg->base.cra_priority;
0751     inst->alg.base.cra_blocksize = 1;
0752     inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
0753 
0754     inst->alg.ivsize = 8;
0755     inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
0756     inst->alg.maxauthsize = 16;
0757 
0758     inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
0759 
0760     inst->alg.init = crypto_rfc4309_init_tfm;
0761     inst->alg.exit = crypto_rfc4309_exit_tfm;
0762 
0763     inst->alg.setkey = crypto_rfc4309_setkey;
0764     inst->alg.setauthsize = crypto_rfc4309_setauthsize;
0765     inst->alg.encrypt = crypto_rfc4309_encrypt;
0766     inst->alg.decrypt = crypto_rfc4309_decrypt;
0767 
0768     inst->free = crypto_rfc4309_free;
0769 
0770     err = aead_register_instance(tmpl, inst);
0771     if (err) {
0772 err_free_inst:
0773         crypto_rfc4309_free(inst);
0774     }
0775     return err;
0776 }
0777 
0778 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
0779                      const u8 *inkey, unsigned int keylen)
0780 {
0781     struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
0782 
0783     return crypto_cipher_setkey(ctx->child, inkey, keylen);
0784 }
0785 
0786 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
0787 {
0788     struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
0789     int bs = crypto_shash_digestsize(pdesc->tfm);
0790     u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
0791 
0792     ctx->len = 0;
0793     memset(dg, 0, bs);
0794 
0795     return 0;
0796 }
0797 
0798 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
0799                        unsigned int len)
0800 {
0801     struct crypto_shash *parent = pdesc->tfm;
0802     struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
0803     struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
0804     struct crypto_cipher *tfm = tctx->child;
0805     int bs = crypto_shash_digestsize(parent);
0806     u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
0807 
0808     while (len > 0) {
0809         unsigned int l = min(len, bs - ctx->len);
0810 
0811         crypto_xor(dg + ctx->len, p, l);
0812         ctx->len +=l;
0813         len -= l;
0814         p += l;
0815 
0816         if (ctx->len == bs) {
0817             crypto_cipher_encrypt_one(tfm, dg, dg);
0818             ctx->len = 0;
0819         }
0820     }
0821 
0822     return 0;
0823 }
0824 
0825 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
0826 {
0827     struct crypto_shash *parent = pdesc->tfm;
0828     struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
0829     struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
0830     struct crypto_cipher *tfm = tctx->child;
0831     int bs = crypto_shash_digestsize(parent);
0832     u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
0833 
0834     if (ctx->len)
0835         crypto_cipher_encrypt_one(tfm, dg, dg);
0836 
0837     memcpy(out, dg, bs);
0838     return 0;
0839 }
0840 
0841 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
0842 {
0843     struct crypto_cipher *cipher;
0844     struct crypto_instance *inst = (void *)tfm->__crt_alg;
0845     struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
0846     struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
0847 
0848     cipher = crypto_spawn_cipher(spawn);
0849     if (IS_ERR(cipher))
0850         return PTR_ERR(cipher);
0851 
0852     ctx->child = cipher;
0853 
0854     return 0;
0855 };
0856 
0857 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
0858 {
0859     struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
0860     crypto_free_cipher(ctx->child);
0861 }
0862 
0863 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
0864 {
0865     struct shash_instance *inst;
0866     struct crypto_cipher_spawn *spawn;
0867     struct crypto_alg *alg;
0868     u32 mask;
0869     int err;
0870 
0871     err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
0872     if (err)
0873         return err;
0874 
0875     inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
0876     if (!inst)
0877         return -ENOMEM;
0878     spawn = shash_instance_ctx(inst);
0879 
0880     err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
0881                  crypto_attr_alg_name(tb[1]), 0, mask);
0882     if (err)
0883         goto err_free_inst;
0884     alg = crypto_spawn_cipher_alg(spawn);
0885 
0886     err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
0887     if (err)
0888         goto err_free_inst;
0889 
0890     inst->alg.base.cra_priority = alg->cra_priority;
0891     inst->alg.base.cra_blocksize = 1;
0892 
0893     inst->alg.digestsize = alg->cra_blocksize;
0894     inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
0895                    alg->cra_alignmask + 1) +
0896                  alg->cra_blocksize;
0897 
0898     inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
0899     inst->alg.base.cra_init = cbcmac_init_tfm;
0900     inst->alg.base.cra_exit = cbcmac_exit_tfm;
0901 
0902     inst->alg.init = crypto_cbcmac_digest_init;
0903     inst->alg.update = crypto_cbcmac_digest_update;
0904     inst->alg.final = crypto_cbcmac_digest_final;
0905     inst->alg.setkey = crypto_cbcmac_digest_setkey;
0906 
0907     inst->free = shash_free_singlespawn_instance;
0908 
0909     err = shash_register_instance(tmpl, inst);
0910     if (err) {
0911 err_free_inst:
0912         shash_free_singlespawn_instance(inst);
0913     }
0914     return err;
0915 }
0916 
0917 static struct crypto_template crypto_ccm_tmpls[] = {
0918     {
0919         .name = "cbcmac",
0920         .create = cbcmac_create,
0921         .module = THIS_MODULE,
0922     }, {
0923         .name = "ccm_base",
0924         .create = crypto_ccm_base_create,
0925         .module = THIS_MODULE,
0926     }, {
0927         .name = "ccm",
0928         .create = crypto_ccm_create,
0929         .module = THIS_MODULE,
0930     }, {
0931         .name = "rfc4309",
0932         .create = crypto_rfc4309_create,
0933         .module = THIS_MODULE,
0934     },
0935 };
0936 
0937 static int __init crypto_ccm_module_init(void)
0938 {
0939     return crypto_register_templates(crypto_ccm_tmpls,
0940                      ARRAY_SIZE(crypto_ccm_tmpls));
0941 }
0942 
0943 static void __exit crypto_ccm_module_exit(void)
0944 {
0945     crypto_unregister_templates(crypto_ccm_tmpls,
0946                     ARRAY_SIZE(crypto_ccm_tmpls));
0947 }
0948 
0949 subsys_initcall(crypto_ccm_module_init);
0950 module_exit(crypto_ccm_module_exit);
0951 
0952 MODULE_LICENSE("GPL");
0953 MODULE_DESCRIPTION("Counter with CBC MAC");
0954 MODULE_ALIAS_CRYPTO("ccm_base");
0955 MODULE_ALIAS_CRYPTO("rfc4309");
0956 MODULE_ALIAS_CRYPTO("ccm");
0957 MODULE_ALIAS_CRYPTO("cbcmac");
0958 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
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