diff options
| -rw-r--r-- | crypto/gcm.c | 190 |
1 files changed, 112 insertions, 78 deletions
diff --git a/crypto/gcm.c b/crypto/gcm.c index c54d478948a0..f6bee6f209a6 100644 --- a/crypto/gcm.c +++ b/crypto/gcm.c @@ -11,6 +11,7 @@ #include <crypto/algapi.h> #include <crypto/gf128mul.h> #include <crypto/scatterwalk.h> +#include <linux/completion.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> @@ -38,11 +39,17 @@ struct crypto_gcm_ghash_ctx { struct crypto_gcm_req_priv_ctx { u8 auth_tag[16]; u8 iauth_tag[16]; - u8 counter[16]; + struct scatterlist src[2]; + struct scatterlist dst[2]; struct crypto_gcm_ghash_ctx ghash; struct ablkcipher_request abreq; }; +struct crypto_gcm_setkey_result { + int err; + struct completion completion; +}; + static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( struct aead_request *req) { @@ -158,33 +165,15 @@ static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx, crypto_xor(dst, buf, 16); } -static inline void crypto_gcm_set_counter(u8 *counterblock, u32 value) +static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err) { - *((u32 *)&counterblock[12]) = cpu_to_be32(value + 1); -} + struct crypto_gcm_setkey_result *result = req->data; -static int crypto_gcm_encrypt_counter(struct crypto_aead *aead, u8 *block, - u32 value, const u8 *iv) -{ - struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); - struct crypto_ablkcipher *ctr = ctx->ctr; - struct ablkcipher_request req; - struct scatterlist sg; - u8 counterblock[16]; - - if (iv == NULL) - memset(counterblock, 0, 12); - else - memcpy(counterblock, iv, 12); - - crypto_gcm_set_counter(counterblock, value); - - sg_init_one(&sg, block, 16); - ablkcipher_request_set_tfm(&req, ctr); - ablkcipher_request_set_crypt(&req, &sg, &sg, 16, counterblock); - ablkcipher_request_set_callback(&req, 0, NULL, NULL); - memset(block, 0, 16); - return crypto_ablkcipher_encrypt(&req); + if (err == -EINPROGRESS) + return; + + result->err = err; + complete(&result->completion); } static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, @@ -192,10 +181,16 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, { struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); struct crypto_ablkcipher *ctr = ctx->ctr; - int alignmask = crypto_ablkcipher_alignmask(ctr); - u8 alignbuf[16+alignmask]; - u8 *hash = (u8 *)ALIGN((unsigned long)alignbuf, alignmask+1); - int err = 0; + struct { + be128 hash; + u8 iv[8]; + + struct crypto_gcm_setkey_result result; + + struct scatterlist sg[1]; + struct ablkcipher_request req; + } *data; + int err; crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) & @@ -203,62 +198,86 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, err = crypto_ablkcipher_setkey(ctr, key, keylen); if (err) - goto out; + return err; crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) & CRYPTO_TFM_RES_MASK); - err = crypto_gcm_encrypt_counter(aead, hash, -1, NULL); + data = kzalloc(sizeof(*data) + crypto_ablkcipher_reqsize(ctr), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + init_completion(&data->result.completion); + sg_init_one(data->sg, &data->hash, sizeof(data->hash)); + ablkcipher_request_set_tfm(&data->req, ctr); + ablkcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP | + CRYPTO_TFM_REQ_MAY_BACKLOG, + crypto_gcm_setkey_done, + &data->result); + ablkcipher_request_set_crypt(&data->req, data->sg, data->sg, + sizeof(data->hash), data->iv); + + err = crypto_ablkcipher_encrypt(&data->req); + if (err == -EINPROGRESS || err == -EBUSY) { + err = wait_for_completion_interruptible( + &data->result.completion); + if (!err) + err = data->result.err; + } + if (err) goto out; if (ctx->gf128 != NULL) gf128mul_free_4k(ctx->gf128); - ctx->gf128 = gf128mul_init_4k_lle((be128 *)hash); + ctx->gf128 = gf128mul_init_4k_lle(&data->hash); if (ctx->gf128 == NULL) err = -ENOMEM; - out: +out: + kfree(data); return err; } -static int crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req, - struct aead_request *req, - unsigned int cryptlen, - void (*done)(struct crypto_async_request *, - int)) +static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req, + struct aead_request *req, + unsigned int cryptlen) { struct crypto_aead *aead = crypto_aead_reqtfm(req); struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); u32 flags = req->base.tfm->crt_flags; - u8 *auth_tag = pctx->auth_tag; - u8 *counter = pctx->counter; struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; - int err = 0; + struct scatterlist *dst; + __be32 counter = cpu_to_be32(1); + + memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag)); + memcpy(req->iv + 12, &counter, 4); + + sg_init_table(pctx->src, 2); + sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag)); + 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, pctx->auth_tag, sizeof(pctx->auth_tag)); + scatterwalk_sg_chain(pctx->dst, 2, req->dst); + dst = pctx->dst; + } ablkcipher_request_set_tfm(ablk_req, ctx->ctr); - ablkcipher_request_set_callback(ablk_req, aead_request_flags(req), - done, req); - ablkcipher_request_set_crypt(ablk_req, req->src, req->dst, - cryptlen, counter); - - err = crypto_gcm_encrypt_counter(aead, auth_tag, 0, req->iv); - if (err) - goto out; - - memcpy(counter, req->iv, 12); - crypto_gcm_set_counter(counter, 1); + ablkcipher_request_set_crypt(ablk_req, pctx->src, dst, + cryptlen + sizeof(pctx->auth_tag), + req->iv); crypto_gcm_ghash_init(ghash, flags, ctx->gf128); crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen); crypto_gcm_ghash_flush(ghash); - - out: - return err; } static int crypto_gcm_hash(struct aead_request *req) @@ -291,25 +310,44 @@ static int crypto_gcm_encrypt(struct aead_request *req) { struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); struct ablkcipher_request *abreq = &pctx->abreq; - int err = 0; + int err; + + crypto_gcm_init_crypt(abreq, req, req->cryptlen); + ablkcipher_request_set_callback(abreq, aead_request_flags(req), + crypto_gcm_encrypt_done, req); - err = crypto_gcm_init_crypt(abreq, req, req->cryptlen, - crypto_gcm_encrypt_done); + err = crypto_ablkcipher_encrypt(abreq); if (err) return err; - if (req->cryptlen) { - err = crypto_ablkcipher_encrypt(abreq); - if (err) - return err; - } - return crypto_gcm_hash(req); } +static int crypto_gcm_verify(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); + struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; + u8 *auth_tag = pctx->auth_tag; + u8 *iauth_tag = pctx->iauth_tag; + unsigned int authsize = crypto_aead_authsize(aead); + unsigned int cryptlen = req->cryptlen - authsize; + + crypto_gcm_ghash_final_xor(ghash, req->assoclen, cryptlen, auth_tag); + + authsize = crypto_aead_authsize(aead); + scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0); + return memcmp(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; +} + static void crypto_gcm_decrypt_done(struct crypto_async_request *areq, int err) { - aead_request_complete(areq->data, err); + struct aead_request *req = areq->data; + + if (!err) + err = crypto_gcm_verify(req); + + aead_request_complete(req, err); } static int crypto_gcm_decrypt(struct aead_request *req) @@ -317,8 +355,6 @@ static int crypto_gcm_decrypt(struct aead_request *req) struct crypto_aead *aead = crypto_aead_reqtfm(req); struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); struct ablkcipher_request *abreq = &pctx->abreq; - u8 *auth_tag = pctx->auth_tag; - u8 *iauth_tag = pctx->iauth_tag; struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; unsigned int cryptlen = req->cryptlen; unsigned int authsize = crypto_aead_authsize(aead); @@ -328,19 +364,17 @@ static int crypto_gcm_decrypt(struct aead_request *req) return -EINVAL; cryptlen -= authsize; - err = crypto_gcm_init_crypt(abreq, req, cryptlen, - crypto_gcm_decrypt_done); - if (err) - return err; + crypto_gcm_init_crypt(abreq, req, cryptlen); + ablkcipher_request_set_callback(abreq, aead_request_flags(req), + crypto_gcm_decrypt_done, req); crypto_gcm_ghash_update_sg(ghash, req->src, cryptlen); - crypto_gcm_ghash_final_xor(ghash, req->assoclen, cryptlen, auth_tag); - scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0); - if (memcmp(iauth_tag, auth_tag, authsize)) - return -EBADMSG; + err = crypto_ablkcipher_decrypt(abreq); + if (err) + return err; - return crypto_ablkcipher_decrypt(abreq); + return crypto_gcm_verify(req); } static int crypto_gcm_init_tfm(struct crypto_tfm *tfm) @@ -436,7 +470,7 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb) inst->alg.cra_blocksize = 16; inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1); inst->alg.cra_type = &crypto_aead_type; - inst->alg.cra_aead.ivsize = 12; + inst->alg.cra_aead.ivsize = 16; inst->alg.cra_aead.maxauthsize = 16; inst->alg.cra_ctxsize = sizeof(struct crypto_gcm_ctx); inst->alg.cra_init = crypto_gcm_init_tfm; |