/* * GCM: Galois/Counter Mode. * * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. */ #include <crypto/gf128mul.h> #include <crypto/internal/aead.h> #include <crypto/internal/skcipher.h> #include <crypto/scatterwalk.h> #include <linux/completion.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> struct gcm_instance_ctx { struct crypto_skcipher_spawn ctr; }; struct crypto_gcm_ctx { struct crypto_ablkcipher *ctr; struct gf128mul_4k *gf128; }; struct crypto_rfc4106_ctx { struct crypto_aead *child; u8 nonce[4]; }; struct crypto_gcm_ghash_ctx { u32 bytes; u32 flags; struct gf128mul_4k *gf128; u8 buffer[16]; }; struct crypto_gcm_req_priv_ctx { u8 auth_tag[16]; u8 iauth_tag[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) { unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); } static void crypto_gcm_ghash_init(struct crypto_gcm_ghash_ctx *ctx, u32 flags, struct gf128mul_4k *gf128) { ctx->bytes = 0; ctx->flags = flags; ctx->gf128 = gf128; memset(ctx->buffer, 0, 16); } static void crypto_gcm_ghash_update(struct crypto_gcm_ghash_ctx *ctx, const u8 *src, unsigned int srclen) { u8 *dst = ctx->buffer; if (ctx->bytes) { int n = min(srclen, ctx->bytes); u8 *pos = dst + (16 - ctx->bytes); ctx->bytes -= n; srclen -= n; while (n--) *pos++ ^= *src++; if (!ctx->bytes) gf128mul_4k_lle((be128 *)dst, ctx->gf128); } while (srclen >= 16) { crypto_xor(dst, src, 16); gf128mul_4k_lle((be128 *)dst, ctx->gf128); src += 16; srclen -= 16; } if (srclen) { ctx->bytes = 16 - srclen; while (srclen--) *dst++ ^= *src++; } } static void crypto_gcm_ghash_update_sg(struct crypto_gcm_ghash_ctx *ctx, struct scatterlist *sg, int len) { struct scatter_walk walk; u8 *src; int n; if (!len) return; scatterwalk_start(&walk, sg); while (len) { n = scatterwalk_clamp(&walk, len); if (!n) { scatterwalk_start(&walk, scatterwalk_sg_next(walk.sg)); n = scatterwalk_clamp(&walk, len); } src = scatterwalk_map(&walk, 0); crypto_gcm_ghash_update(ctx, src, n); len -= n; scatterwalk_unmap(src, 0); scatterwalk_advance(&walk, n); scatterwalk_done(&walk, 0, len); if (len) crypto_yield(ctx->flags); } } static void crypto_gcm_ghash_flush(struct crypto_gcm_ghash_ctx *ctx) { u8 *dst = ctx->buffer; if (ctx->bytes) { u8 *tmp = dst + (16 - ctx->bytes); while (ctx->bytes--) *tmp++ ^= 0; gf128mul_4k_lle((be128 *)dst, ctx->gf128); } ctx->bytes = 0; } static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx, unsigned int authlen, unsigned int cryptlen, u8 *dst) { u8 *buf = ctx->buffer; u128 lengths; lengths.a = cpu_to_be64(authlen * 8); lengths.b = cpu_to_be64(cryptlen * 8); crypto_gcm_ghash_flush(ctx); crypto_xor(buf, (u8 *)&lengths, 16); gf128mul_4k_lle((be128 *)buf, ctx->gf128); crypto_xor(dst, buf, 16); } static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err) { struct crypto_gcm_setkey_result *result = req->data; if (err == -EINPROGRESS) return; result->err = err; complete(&result->completion); } static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, unsigned int keylen) { struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); struct crypto_ablkcipher *ctr = ctx->ctr; 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) & CRYPTO_TFM_REQ_MASK); err = crypto_ablkcipher_setkey(ctr, key, keylen); if (err) return err; crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) & CRYPTO_TFM_RES_MASK); 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(&data->hash); if (ctx->gf128 == NULL) err = -ENOMEM; out: kfree(data); return err; } static int crypto_gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) { switch (authsize) { case 4: case 8: case 12: case 13: case 14: case 15: case 16: break; default: return -EINVAL; } return 0; } 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; struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; 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_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); } static int crypto_gcm_hash(struct aead_request *req) { struct crypto_aead *aead = crypto_aead_reqtfm(req); struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); u8 *auth_tag = pctx->auth_tag; struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; crypto_gcm_ghash_update_sg(ghash, req->dst, req->cryptlen); crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen, auth_tag); scatterwalk_map_and_copy(auth_tag, req->dst, req->cryptlen, crypto_aead_authsize(aead), 1); return 0; } static void crypto_gcm_encrypt_done(struct crypto_async_request *areq, int err) { struct aead_request *req = areq->data; if (!err) err = crypto_gcm_hash(req); aead_request_complete(req, err); } 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; crypto_gcm_init_crypt(abreq, req, req->cryptlen); ablkcipher_request_set_callback(abreq, aead_request_flags(req), crypto_gcm_encrypt_done, req); 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) { 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) { 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; struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; unsigned int cryptlen = req->cryptlen; unsigned int authsize = crypto_aead_authsize(aead); int err; if (cryptlen < authsize) return -EINVAL; cryptlen -= authsize; 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); err = crypto_ablkcipher_decrypt(abreq); if (err) return err; return crypto_gcm_verify(req); } static int crypto_gcm_init_tfm(struct crypto_tfm *tfm) { struct crypto_instance *inst = (void *)tfm->__crt_alg; struct gcm_instance_ctx *ictx = crypto_instance_ctx(inst); struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm); struct crypto_ablkcipher *ctr; unsigned long align; int err; ctr = crypto_spawn_skcipher(&ictx->ctr); err = PTR_ERR(ctr); if (IS_ERR(ctr)) return err; ctx->ctr = ctr; ctx->gf128 = NULL; align = crypto_tfm_alg_alignmask(tfm); align &= ~(crypto_tfm_ctx_alignment() - 1); tfm->crt_aead.reqsize = align + sizeof(struct crypto_gcm_req_priv_ctx) + crypto_ablkcipher_reqsize(ctr); return 0; } static void crypto_gcm_exit_tfm(struct crypto_tfm *tfm) { struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm); if (ctx->gf128 != NULL) gf128mul_free_4k(ctx->gf128); crypto_free_ablkcipher(ctx->ctr); } static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb, const char *full_name, const char *ctr_name) { struct crypto_attr_type *algt; struct crypto_instance *inst; struct crypto_alg *ctr; struct gcm_instance_ctx *ctx; 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); inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); if (!inst) return ERR_PTR(-ENOMEM); ctx = crypto_instance_ctx(inst); crypto_set_skcipher_spawn(&ctx->ctr, inst); err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0, crypto_requires_sync(algt->type, algt->mask)); if (err) goto err_free_inst; ctr = crypto_skcipher_spawn_alg(&ctx->ctr); /* We only support 16-byte blocks. */ if (ctr->cra_ablkcipher.ivsize != 16) goto out_put_ctr; /* Not a stream cipher? */ err = -EINVAL; if (ctr->cra_blocksize != 1) goto out_put_ctr; err = -ENAMETOOLONG; if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)", ctr->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) goto out_put_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 = ctr->cra_priority; inst->alg.cra_blocksize = 1; inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 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_gcm_ctx); inst->alg.cra_init = crypto_gcm_init_tfm; inst->alg.cra_exit = crypto_gcm_exit_tfm; inst->alg.cra_aead.setkey = crypto_gcm_setkey; inst->alg.cra_aead.setauthsize = crypto_gcm_setauthsize; inst->alg.cra_aead.encrypt = crypto_gcm_encrypt; inst->alg.cra_aead.decrypt = crypto_gcm_decrypt; out: return inst; out_put_ctr: crypto_drop_skcipher(&ctx->ctr); err_free_inst: kfree(inst); inst = ERR_PTR(err); goto out; } static struct crypto_instance *crypto_gcm_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, "gcm(%s)", cipher_name) >= CRYPTO_MAX_ALG_NAME) return ERR_PTR(-ENAMETOOLONG); return crypto_gcm_alloc_common(tb, full_name, ctr_name); } static void crypto_gcm_free(struct crypto_instance *inst) { struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst); crypto_drop_skcipher(&ctx->ctr); kfree(inst); } static struct crypto_template crypto_gcm_tmpl = { .name = "gcm", .alloc = crypto_gcm_alloc, .free = crypto_gcm_free, .module = THIS_MODULE, }; static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb) { int err; const char *ctr_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); if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)", ctr_name) >= CRYPTO_MAX_ALG_NAME) return ERR_PTR(-ENAMETOOLONG); return crypto_gcm_alloc_common(tb, full_name, ctr_name); } static struct crypto_template crypto_gcm_base_tmpl = { .name = "gcm_base", .alloc = crypto_gcm_base_alloc, .free = crypto_gcm_free, .module = THIS_MODULE, }; static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key, unsigned int keylen) { struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); struct crypto_aead *child = ctx->child; int err; if (keylen < 4) return -EINVAL; keylen -= 4; memcpy(ctx->nonce, key + keylen, 4); 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_rfc4106_setauthsize(struct crypto_aead *parent, unsigned int authsize) { struct crypto_rfc4106_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_rfc4106_crypt(struct aead_request *req) { struct aead_request *subreq = aead_request_ctx(req); struct crypto_aead *aead = crypto_aead_reqtfm(req); struct crypto_rfc4106_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); memcpy(iv, ctx->nonce, 4); 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_rfc4106_encrypt(struct aead_request *req) { req = crypto_rfc4106_crypt(req); return crypto_aead_encrypt(req); } static int crypto_rfc4106_decrypt(struct aead_request *req) { req = crypto_rfc4106_crypt(req); return crypto_aead_decrypt(req); } static int crypto_rfc4106_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_rfc4106_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_rfc4106_exit_tfm(struct crypto_tfm *tfm) { struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm); crypto_free_aead(ctx->child); } static struct crypto_instance *crypto_rfc4106_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, "rfc4106(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME || snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "rfc4106(%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_rfc4106_ctx); inst->alg.cra_init = crypto_rfc4106_init_tfm; inst->alg.cra_exit = crypto_rfc4106_exit_tfm; inst->alg.cra_aead.setkey = crypto_rfc4106_setkey; inst->alg.cra_aead.setauthsize = crypto_rfc4106_setauthsize; inst->alg.cra_aead.encrypt = crypto_rfc4106_encrypt; inst->alg.cra_aead.decrypt = crypto_rfc4106_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_rfc4106_free(struct crypto_instance *inst) { crypto_drop_spawn(crypto_instance_ctx(inst)); kfree(inst); } static struct crypto_template crypto_rfc4106_tmpl = { .name = "rfc4106", .alloc = crypto_rfc4106_alloc, .free = crypto_rfc4106_free, .module = THIS_MODULE, }; static int __init crypto_gcm_module_init(void) { int err; err = crypto_register_template(&crypto_gcm_base_tmpl); if (err) goto out; err = crypto_register_template(&crypto_gcm_tmpl); if (err) goto out_undo_base; err = crypto_register_template(&crypto_rfc4106_tmpl); if (err) goto out_undo_gcm; out: return err; out_undo_gcm: crypto_unregister_template(&crypto_gcm_tmpl); out_undo_base: crypto_unregister_template(&crypto_gcm_base_tmpl); goto out; } static void __exit crypto_gcm_module_exit(void) { crypto_unregister_template(&crypto_rfc4106_tmpl); crypto_unregister_template(&crypto_gcm_tmpl); crypto_unregister_template(&crypto_gcm_base_tmpl); } module_init(crypto_gcm_module_init); module_exit(crypto_gcm_module_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Galois/Counter Mode"); MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); MODULE_ALIAS("gcm_base"); MODULE_ALIAS("rfc4106");