diff options
Diffstat (limited to 'crypto/ccm.c')
| -rw-r--r-- | crypto/ccm.c | 889 |
1 files changed, 889 insertions, 0 deletions
diff --git a/crypto/ccm.c b/crypto/ccm.c new file mode 100644 index 0000000..7cf7e5a --- /dev/null +++ b/crypto/ccm.c @@ -0,0 +1,889 @@ +/* + * CCM: Counter with CBC-MAC + * + * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#include <crypto/internal/aead.h> +#include <crypto/internal/skcipher.h> +#include <crypto/scatterwalk.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include "internal.h" + +struct ccm_instance_ctx { + struct crypto_skcipher_spawn ctr; + struct crypto_spawn cipher; +}; + +struct crypto_ccm_ctx { + struct crypto_cipher *cipher; + struct crypto_ablkcipher *ctr; +}; + +struct crypto_rfc4309_ctx { + struct crypto_aead *child; + u8 nonce[3]; +}; + +struct crypto_ccm_req_priv_ctx { + u8 odata[16]; + u8 idata[16]; + u8 auth_tag[16]; + u32 ilen; + u32 flags; + struct scatterlist src[2]; + struct scatterlist dst[2]; + struct ablkcipher_request abreq; +}; + +static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx( + struct aead_request *req) +{ + unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); + + return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); +} + +static int set_msg_len(u8 *block, unsigned int msglen, int csize) +{ + __be32 data; + + memset(block, 0, csize); + block += csize; + + if (csize >= 4) + csize = 4; + else if (msglen > (1 << (8 * csize))) + return -EOVERFLOW; + + data = cpu_to_be32(msglen); + memcpy(block - csize, (u8 *)&data + 4 - csize, csize); + + return 0; +} + +static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key, + unsigned int keylen) +{ + struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_ablkcipher *ctr = ctx->ctr; + struct crypto_cipher *tfm = ctx->cipher; + int err = 0; + + crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); + crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) & + CRYPTO_TFM_REQ_MASK); + err = crypto_ablkcipher_setkey(ctr, key, keylen); + crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) & + CRYPTO_TFM_RES_MASK); + if (err) + goto out; + + crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK); + crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) & + CRYPTO_TFM_REQ_MASK); + err = crypto_cipher_setkey(tfm, key, keylen); + crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) & + CRYPTO_TFM_RES_MASK); + +out: + return err; +} + +static int crypto_ccm_setauthsize(struct crypto_aead *tfm, + unsigned int authsize) +{ + switch (authsize) { + case 4: + case 6: + case 8: + case 10: + case 12: + case 14: + case 16: + break; + default: + return -EINVAL; + } + + return 0; +} + +static int format_input(u8 *info, struct aead_request *req, + unsigned int cryptlen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + unsigned int lp = req->iv[0]; + unsigned int l = lp + 1; + unsigned int m; + + m = crypto_aead_authsize(aead); + + memcpy(info, req->iv, 16); + + /* format control info per RFC 3610 and + * NIST Special Publication 800-38C + */ + *info |= (8 * ((m - 2) / 2)); + if (req->assoclen) + *info |= 64; + + return set_msg_len(info + 16 - l, cryptlen, l); +} + +static int format_adata(u8 *adata, unsigned int a) +{ + int len = 0; + + /* add control info for associated data + * RFC 3610 and NIST Special Publication 800-38C + */ + if (a < 65280) { + *(__be16 *)adata = cpu_to_be16(a); + len = 2; + } else { + *(__be16 *)adata = cpu_to_be16(0xfffe); + *(__be32 *)&adata[2] = cpu_to_be32(a); + len = 6; + } + + return len; +} + +static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n, + struct crypto_ccm_req_priv_ctx *pctx) +{ + unsigned int bs = 16; + u8 *odata = pctx->odata; + u8 *idata = pctx->idata; + int datalen, getlen; + + datalen = n; + + /* first time in here, block may be partially filled. */ + getlen = bs - pctx->ilen; + if (datalen >= getlen) { + memcpy(idata + pctx->ilen, data, getlen); + crypto_xor(odata, idata, bs); + crypto_cipher_encrypt_one(tfm, odata, odata); + datalen -= getlen; + data += getlen; + pctx->ilen = 0; + } + + /* now encrypt rest of data */ + while (datalen >= bs) { + crypto_xor(odata, data, bs); + crypto_cipher_encrypt_one(tfm, odata, odata); + + datalen -= bs; + data += bs; + } + + /* check and see if there's leftover data that wasn't + * enough to fill a block. + */ + if (datalen) { + memcpy(idata + pctx->ilen, data, datalen); + pctx->ilen += datalen; + } +} + +static void get_data_to_compute(struct crypto_cipher *tfm, + struct crypto_ccm_req_priv_ctx *pctx, + struct scatterlist *sg, unsigned int len) +{ + struct scatter_walk walk; + u8 *data_src; + int n; + + scatterwalk_start(&walk, sg); + + while (len) { + n = scatterwalk_clamp(&walk, len); + if (!n) { + scatterwalk_start(&walk, sg_next(walk.sg)); + n = scatterwalk_clamp(&walk, len); + } + data_src = scatterwalk_map(&walk, 0); + + compute_mac(tfm, data_src, n, pctx); + len -= n; + + scatterwalk_unmap(data_src, 0); + scatterwalk_advance(&walk, n); + scatterwalk_done(&walk, 0, len); + if (len) + crypto_yield(pctx->flags); + } + + /* any leftover needs padding and then encrypted */ + if (pctx->ilen) { + int padlen; + u8 *odata = pctx->odata; + u8 *idata = pctx->idata; + + padlen = 16 - pctx->ilen; + memset(idata + pctx->ilen, 0, padlen); + crypto_xor(odata, idata, 16); + crypto_cipher_encrypt_one(tfm, odata, odata); + pctx->ilen = 0; + } +} + +static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain, + unsigned int cryptlen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); + struct crypto_cipher *cipher = ctx->cipher; + unsigned int assoclen = req->assoclen; + u8 *odata = pctx->odata; + u8 *idata = pctx->idata; + int err; + + /* format control data for input */ + err = format_input(odata, req, cryptlen); + if (err) + goto out; + + /* encrypt first block to use as start in computing mac */ + crypto_cipher_encrypt_one(cipher, odata, odata); + + /* format associated data and compute into mac */ + if (assoclen) { + pctx->ilen = format_adata(idata, assoclen); + get_data_to_compute(cipher, pctx, req->assoc, req->assoclen); + } + + /* compute plaintext into mac */ + get_data_to_compute(cipher, pctx, plain, cryptlen); + +out: + return err; +} + +static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err) +{ + struct aead_request *req = areq->data; + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); + u8 *odata = pctx->odata; + + if (!err) + scatterwalk_map_and_copy(odata, req->dst, req->cryptlen, + crypto_aead_authsize(aead), 1); + aead_request_complete(req, err); +} + +static inline int crypto_ccm_check_iv(const u8 *iv) +{ + /* 2 <= L <= 8, so 1 <= L' <= 7. */ + if (1 > iv[0] || iv[0] > 7) + return -EINVAL; + + return 0; +} + +static int crypto_ccm_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); + struct ablkcipher_request *abreq = &pctx->abreq; + struct scatterlist *dst; + unsigned int cryptlen = req->cryptlen; + u8 *odata = pctx->odata; + u8 *iv = req->iv; + int err; + + err = crypto_ccm_check_iv(iv); + if (err) + return err; + + pctx->flags = aead_request_flags(req); + + err = crypto_ccm_auth(req, req->src, cryptlen); + if (err) + return err; + + /* Note: rfc 3610 and NIST 800-38C require counter of + * zero to encrypt auth tag. + */ + memset(iv + 15 - iv[0], 0, iv[0] + 1); + + sg_init_table(pctx->src, 2); + sg_set_buf(pctx->src, odata, 16); + scatterwalk_sg_chain(pctx->src, 2, req->src); + + dst = pctx->src; + if (req->src != req->dst) { + sg_init_table(pctx->dst, 2); + sg_set_buf(pctx->dst, odata, 16); + scatterwalk_sg_chain(pctx->dst, 2, req->dst); + dst = pctx->dst; + } + + ablkcipher_request_set_tfm(abreq, ctx->ctr); + ablkcipher_request_set_callback(abreq, pctx->flags, + crypto_ccm_encrypt_done, req); + ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv); + err = crypto_ablkcipher_encrypt(abreq); + if (err) + return err; + + /* copy authtag to end of dst */ + scatterwalk_map_and_copy(odata, req->dst, cryptlen, + crypto_aead_authsize(aead), 1); + return err; +} + +static void crypto_ccm_decrypt_done(struct crypto_async_request *areq, + int err) +{ + struct aead_request *req = areq->data; + struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); + struct crypto_aead *aead = crypto_aead_reqtfm(req); + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int cryptlen = req->cryptlen - authsize; + + if (!err) { + err = crypto_ccm_auth(req, req->dst, cryptlen); + if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize)) + err = -EBADMSG; + } + aead_request_complete(req, err); +} + +static int crypto_ccm_decrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); + struct ablkcipher_request *abreq = &pctx->abreq; + struct scatterlist *dst; + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int cryptlen = req->cryptlen; + u8 *authtag = pctx->auth_tag; + u8 *odata = pctx->odata; + u8 *iv = req->iv; + int err; + + if (cryptlen < authsize) + return -EINVAL; + cryptlen -= authsize; + + err = crypto_ccm_check_iv(iv); + if (err) + return err; + + pctx->flags = aead_request_flags(req); + + scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0); + + memset(iv + 15 - iv[0], 0, iv[0] + 1); + + sg_init_table(pctx->src, 2); + sg_set_buf(pctx->src, authtag, 16); + scatterwalk_sg_chain(pctx->src, 2, req->src); + + dst = pctx->src; + if (req->src != req->dst) { + sg_init_table(pctx->dst, 2); + sg_set_buf(pctx->dst, authtag, 16); + scatterwalk_sg_chain(pctx->dst, 2, req->dst); + dst = pctx->dst; + } + + ablkcipher_request_set_tfm(abreq, ctx->ctr); + ablkcipher_request_set_callback(abreq, pctx->flags, + crypto_ccm_decrypt_done, req); + ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv); + err = crypto_ablkcipher_decrypt(abreq); + if (err) + return err; + + err = crypto_ccm_auth(req, req->dst, cryptlen); + if (err) + return err; + + /* verify */ + if (memcmp(authtag, odata, authsize)) + return -EBADMSG; + + return err; +} + +static int crypto_ccm_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst); + struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm); + struct crypto_cipher *cipher; + struct crypto_ablkcipher *ctr; + unsigned long align; + int err; + + cipher = crypto_spawn_cipher(&ictx->cipher); + if (IS_ERR(cipher)) + return PTR_ERR(cipher); + + ctr = crypto_spawn_skcipher(&ictx->ctr); + err = PTR_ERR(ctr); + if (IS_ERR(ctr)) + goto err_free_cipher; + + ctx->cipher = cipher; + ctx->ctr = ctr; + + align = crypto_tfm_alg_alignmask(tfm); + align &= ~(crypto_tfm_ctx_alignment() - 1); + tfm->crt_aead.reqsize = align + + sizeof(struct crypto_ccm_req_priv_ctx) + + crypto_ablkcipher_reqsize(ctr); + + return 0; + +err_free_cipher: + crypto_free_cipher(cipher); + return err; +} + +static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm); + + crypto_free_cipher(ctx->cipher); + crypto_free_ablkcipher(ctx->ctr); +} + +static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb, + const char *full_name, + const char *ctr_name, + const char *cipher_name) +{ + struct crypto_attr_type *algt; + struct crypto_instance *inst; + struct crypto_alg *ctr; + struct crypto_alg *cipher; + struct ccm_instance_ctx *ictx; + int err; + + algt = crypto_get_attr_type(tb); + err = PTR_ERR(algt); + if (IS_ERR(algt)) + return ERR_PTR(err); + + if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) + return ERR_PTR(-EINVAL); + + cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER, + CRYPTO_ALG_TYPE_MASK); + err = PTR_ERR(cipher); + if (IS_ERR(cipher)) + return ERR_PTR(err); + + err = -EINVAL; + if (cipher->cra_blocksize != 16) + goto out_put_cipher; + + inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL); + err = -ENOMEM; + if (!inst) + goto out_put_cipher; + + ictx = crypto_instance_ctx(inst); + + err = crypto_init_spawn(&ictx->cipher, cipher, inst, + CRYPTO_ALG_TYPE_MASK); + if (err) + goto err_free_inst; + + crypto_set_skcipher_spawn(&ictx->ctr, inst); + err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0, + crypto_requires_sync(algt->type, + algt->mask)); + if (err) + goto err_drop_cipher; + + ctr = crypto_skcipher_spawn_alg(&ictx->ctr); + + /* Not a stream cipher? */ + err = -EINVAL; + if (ctr->cra_blocksize != 1) + goto err_drop_ctr; + + /* We want the real thing! */ + if (ctr->cra_ablkcipher.ivsize != 16) + goto err_drop_ctr; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "ccm_base(%s,%s)", ctr->cra_driver_name, + cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) + goto err_drop_ctr; + + memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME); + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; + inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC; + inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority; + inst->alg.cra_blocksize = 1; + inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask | + (__alignof__(u32) - 1); + inst->alg.cra_type = &crypto_aead_type; + inst->alg.cra_aead.ivsize = 16; + inst->alg.cra_aead.maxauthsize = 16; + inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx); + inst->alg.cra_init = crypto_ccm_init_tfm; + inst->alg.cra_exit = crypto_ccm_exit_tfm; + inst->alg.cra_aead.setkey = crypto_ccm_setkey; + inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize; + inst->alg.cra_aead.encrypt = crypto_ccm_encrypt; + inst->alg.cra_aead.decrypt = crypto_ccm_decrypt; + +out: + crypto_mod_put(cipher); + return inst; + +err_drop_ctr: + crypto_drop_skcipher(&ictx->ctr); +err_drop_cipher: + crypto_drop_spawn(&ictx->cipher); +err_free_inst: + kfree(inst); +out_put_cipher: + inst = ERR_PTR(err); + goto out; +} + +static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb) +{ + int err; + const char *cipher_name; + char ctr_name[CRYPTO_MAX_ALG_NAME]; + char full_name[CRYPTO_MAX_ALG_NAME]; + + cipher_name = crypto_attr_alg_name(tb[1]); + err = PTR_ERR(cipher_name); + if (IS_ERR(cipher_name)) + return ERR_PTR(err); + + if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", + cipher_name) >= CRYPTO_MAX_ALG_NAME) + return ERR_PTR(-ENAMETOOLONG); + + if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >= + CRYPTO_MAX_ALG_NAME) + return ERR_PTR(-ENAMETOOLONG); + + return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name); +} + +static void crypto_ccm_free(struct crypto_instance *inst) +{ + struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst); + + crypto_drop_spawn(&ctx->cipher); + crypto_drop_skcipher(&ctx->ctr); + kfree(inst); +} + +static struct crypto_template crypto_ccm_tmpl = { + .name = "ccm", + .alloc = crypto_ccm_alloc, + .free = crypto_ccm_free, + .module = THIS_MODULE, +}; + +static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb) +{ + int err; + const char *ctr_name; + const char *cipher_name; + char full_name[CRYPTO_MAX_ALG_NAME]; + + ctr_name = crypto_attr_alg_name(tb[1]); + err = PTR_ERR(ctr_name); + if (IS_ERR(ctr_name)) + return ERR_PTR(err); + + cipher_name = crypto_attr_alg_name(tb[2]); + err = PTR_ERR(cipher_name); + if (IS_ERR(cipher_name)) + return ERR_PTR(err); + + if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)", + ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME) + return ERR_PTR(-ENAMETOOLONG); + + return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name); +} + +static struct crypto_template crypto_ccm_base_tmpl = { + .name = "ccm_base", + .alloc = crypto_ccm_base_alloc, + .free = crypto_ccm_free, + .module = THIS_MODULE, +}; + +static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key, + unsigned int keylen) +{ + struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); + struct crypto_aead *child = ctx->child; + int err; + + if (keylen < 3) + return -EINVAL; + + keylen -= 3; + memcpy(ctx->nonce, key + keylen, 3); + + crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); + crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + err = crypto_aead_setkey(child, key, keylen); + crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & + CRYPTO_TFM_RES_MASK); + + return err; +} + +static int crypto_rfc4309_setauthsize(struct crypto_aead *parent, + unsigned int authsize) +{ + struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); + + switch (authsize) { + case 8: + case 12: + case 16: + break; + default: + return -EINVAL; + } + + return crypto_aead_setauthsize(ctx->child, authsize); +} + +static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req) +{ + struct aead_request *subreq = aead_request_ctx(req); + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead); + struct crypto_aead *child = ctx->child; + u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), + crypto_aead_alignmask(child) + 1); + + /* L' */ + iv[0] = 3; + + memcpy(iv + 1, ctx->nonce, 3); + memcpy(iv + 4, req->iv, 8); + + aead_request_set_tfm(subreq, child); + aead_request_set_callback(subreq, req->base.flags, req->base.complete, + req->base.data); + aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv); + aead_request_set_assoc(subreq, req->assoc, req->assoclen); + + return subreq; +} + +static int crypto_rfc4309_encrypt(struct aead_request *req) +{ + req = crypto_rfc4309_crypt(req); + + return crypto_aead_encrypt(req); +} + +static int crypto_rfc4309_decrypt(struct aead_request *req) +{ + req = crypto_rfc4309_crypt(req); + + return crypto_aead_decrypt(req); +} + +static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst); + struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm); + struct crypto_aead *aead; + unsigned long align; + + aead = crypto_spawn_aead(spawn); + if (IS_ERR(aead)) + return PTR_ERR(aead); + + ctx->child = aead; + + align = crypto_aead_alignmask(aead); + align &= ~(crypto_tfm_ctx_alignment() - 1); + tfm->crt_aead.reqsize = sizeof(struct aead_request) + + ALIGN(crypto_aead_reqsize(aead), + crypto_tfm_ctx_alignment()) + + align + 16; + + return 0; +} + +static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm); + + crypto_free_aead(ctx->child); +} + +static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb) +{ + struct crypto_attr_type *algt; + struct crypto_instance *inst; + struct crypto_aead_spawn *spawn; + struct crypto_alg *alg; + const char *ccm_name; + int err; + + algt = crypto_get_attr_type(tb); + err = PTR_ERR(algt); + if (IS_ERR(algt)) + return ERR_PTR(err); + + if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) + return ERR_PTR(-EINVAL); + + ccm_name = crypto_attr_alg_name(tb[1]); + err = PTR_ERR(ccm_name); + if (IS_ERR(ccm_name)) + return ERR_PTR(err); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + + spawn = crypto_instance_ctx(inst); + crypto_set_aead_spawn(spawn, inst); + err = crypto_grab_aead(spawn, ccm_name, 0, + crypto_requires_sync(algt->type, algt->mask)); + if (err) + goto out_free_inst; + + alg = crypto_aead_spawn_alg(spawn); + + err = -EINVAL; + + /* We only support 16-byte blocks. */ + if (alg->cra_aead.ivsize != 16) + goto out_drop_alg; + + /* Not a stream cipher? */ + if (alg->cra_blocksize != 1) + goto out_drop_alg; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, + "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME || + snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "rfc4309(%s)", alg->cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto out_drop_alg; + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; + inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; + inst->alg.cra_priority = alg->cra_priority; + inst->alg.cra_blocksize = 1; + inst->alg.cra_alignmask = alg->cra_alignmask; + inst->alg.cra_type = &crypto_nivaead_type; + + inst->alg.cra_aead.ivsize = 8; + inst->alg.cra_aead.maxauthsize = 16; + + inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx); + + inst->alg.cra_init = crypto_rfc4309_init_tfm; + inst->alg.cra_exit = crypto_rfc4309_exit_tfm; + + inst->alg.cra_aead.setkey = crypto_rfc4309_setkey; + inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize; + inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt; + inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt; + + inst->alg.cra_aead.geniv = "seqiv"; + +out: + return inst; + +out_drop_alg: + crypto_drop_aead(spawn); +out_free_inst: + kfree(inst); + inst = ERR_PTR(err); + goto out; +} + +static void crypto_rfc4309_free(struct crypto_instance *inst) +{ + crypto_drop_spawn(crypto_instance_ctx(inst)); + kfree(inst); +} + +static struct crypto_template crypto_rfc4309_tmpl = { + .name = "rfc4309", + .alloc = crypto_rfc4309_alloc, + .free = crypto_rfc4309_free, + .module = THIS_MODULE, +}; + +static int __init crypto_ccm_module_init(void) +{ + int err; + + err = crypto_register_template(&crypto_ccm_base_tmpl); + if (err) + goto out; + + err = crypto_register_template(&crypto_ccm_tmpl); + if (err) + goto out_undo_base; + + err = crypto_register_template(&crypto_rfc4309_tmpl); + if (err) + goto out_undo_ccm; + +out: + return err; + +out_undo_ccm: + crypto_unregister_template(&crypto_ccm_tmpl); +out_undo_base: + crypto_unregister_template(&crypto_ccm_base_tmpl); + goto out; +} + +static void __exit crypto_ccm_module_exit(void) +{ + crypto_unregister_template(&crypto_rfc4309_tmpl); + crypto_unregister_template(&crypto_ccm_tmpl); + crypto_unregister_template(&crypto_ccm_base_tmpl); +} + +module_init(crypto_ccm_module_init); +module_exit(crypto_ccm_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Counter with CBC MAC"); +MODULE_ALIAS("ccm_base"); +MODULE_ALIAS("rfc4309"); |
