/* * seqiv: Sequence Number IV Generator * * This generator generates an IV based on a sequence number by xoring it * with a salt. This algorithm is mainly useful for CTR and similar modes. * * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> * * 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/geniv.h> #include <crypto/internal/skcipher.h> #include <crypto/null.h> #include <crypto/rng.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 <linux/spinlock.h> #include <linux/string.h> struct seqniv_request_ctx { struct scatterlist dst[2]; struct aead_request subreq; }; struct seqiv_ctx { spinlock_t lock; u8 salt[] __attribute__ ((aligned(__alignof__(u32)))); }; struct seqiv_aead_ctx { /* aead_geniv_ctx must be first the element */ struct aead_geniv_ctx geniv; struct crypto_blkcipher *null; u8 salt[] __attribute__ ((aligned(__alignof__(u32)))); }; static void seqiv_free(struct crypto_instance *inst); static void seqiv_complete2(struct skcipher_givcrypt_request *req, int err) { struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req); struct crypto_ablkcipher *geniv; if (err == -EINPROGRESS) return; if (err) goto out; geniv = skcipher_givcrypt_reqtfm(req); memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv)); out: kfree(subreq->info); } static void seqiv_complete(struct crypto_async_request *base, int err) { struct skcipher_givcrypt_request *req = base->data; seqiv_complete2(req, err); skcipher_givcrypt_complete(req, err); } static void seqiv_aead_complete2(struct aead_givcrypt_request *req, int err) { struct aead_request *subreq = aead_givcrypt_reqctx(req); struct crypto_aead *geniv; if (err == -EINPROGRESS) return; if (err) goto out; geniv = aead_givcrypt_reqtfm(req); memcpy(req->areq.iv, subreq->iv, crypto_aead_ivsize(geniv)); out: kfree(subreq->iv); } static void seqiv_aead_complete(struct crypto_async_request *base, int err) { struct aead_givcrypt_request *req = base->data; seqiv_aead_complete2(req, err); aead_givcrypt_complete(req, err); } static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err) { struct aead_request *subreq = aead_request_ctx(req); struct crypto_aead *geniv; if (err == -EINPROGRESS) return; if (err) goto out; geniv = crypto_aead_reqtfm(req); memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv)); out: kzfree(subreq->iv); } static void seqiv_aead_encrypt_complete(struct crypto_async_request *base, int err) { struct aead_request *req = base->data; seqiv_aead_encrypt_complete2(req, err); aead_request_complete(req, err); } static void seqniv_aead_encrypt_complete2(struct aead_request *req, int err) { unsigned int ivsize = 8; u8 data[20]; if (err == -EINPROGRESS) return; /* Swap IV and ESP header back to correct order. */ scatterwalk_map_and_copy(data, req->dst, 0, req->assoclen + ivsize, 0); scatterwalk_map_and_copy(data + ivsize, req->dst, 0, req->assoclen, 1); scatterwalk_map_and_copy(data, req->dst, req->assoclen, ivsize, 1); } static void seqniv_aead_encrypt_complete(struct crypto_async_request *base, int err) { struct aead_request *req = base->data; seqniv_aead_encrypt_complete2(req, err); aead_request_complete(req, err); } static void seqniv_aead_decrypt_complete2(struct aead_request *req, int err) { u8 data[4]; if (err == -EINPROGRESS) return; /* Move ESP header back to correct location. */ scatterwalk_map_and_copy(data, req->dst, 16, req->assoclen - 8, 0); scatterwalk_map_and_copy(data, req->dst, 8, req->assoclen - 8, 1); } static void seqniv_aead_decrypt_complete(struct crypto_async_request *base, int err) { struct aead_request *req = base->data; seqniv_aead_decrypt_complete2(req, err); aead_request_complete(req, err); } static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq, unsigned int ivsize) { unsigned int len = ivsize; if (ivsize > sizeof(u64)) { memset(info, 0, ivsize - sizeof(u64)); len = sizeof(u64); } seq = cpu_to_be64(seq); memcpy(info + ivsize - len, &seq, len); crypto_xor(info, ctx->salt, ivsize); } static int seqiv_givencrypt(struct skcipher_givcrypt_request *req) { struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req); struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req); crypto_completion_t compl; void *data; u8 *info; unsigned int ivsize; int err; ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv)); compl = req->creq.base.complete; data = req->creq.base.data; info = req->creq.info; ivsize = crypto_ablkcipher_ivsize(geniv); if (unlikely(!IS_ALIGNED((unsigned long)info, crypto_ablkcipher_alignmask(geniv) + 1))) { info = kmalloc(ivsize, req->creq.base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: GFP_ATOMIC); if (!info) return -ENOMEM; compl = seqiv_complete; data = req; } ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl, data); ablkcipher_request_set_crypt(subreq, req->creq.src, req->creq.dst, req->creq.nbytes, info); seqiv_geniv(ctx, info, req->seq, ivsize); memcpy(req->giv, info, ivsize); err = crypto_ablkcipher_encrypt(subreq); if (unlikely(info != req->creq.info)) seqiv_complete2(req, err); return err; } static int seqiv_aead_givencrypt(struct aead_givcrypt_request *req) { struct crypto_aead *geniv = aead_givcrypt_reqtfm(req); struct seqiv_ctx *ctx = crypto_aead_ctx(geniv); struct aead_request *areq = &req->areq; struct aead_request *subreq = aead_givcrypt_reqctx(req); crypto_completion_t compl; void *data; u8 *info; unsigned int ivsize; int err; aead_request_set_tfm(subreq, aead_geniv_base(geniv)); compl = areq->base.complete; data = areq->base.data; info = areq->iv; ivsize = crypto_aead_ivsize(geniv); if (unlikely(!IS_ALIGNED((unsigned long)info, crypto_aead_alignmask(geniv) + 1))) { info = kmalloc(ivsize, areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: GFP_ATOMIC); if (!info) return -ENOMEM; compl = seqiv_aead_complete; data = req; } aead_request_set_callback(subreq, areq->base.flags, compl, data); aead_request_set_crypt(subreq, areq->src, areq->dst, areq->cryptlen, info); aead_request_set_assoc(subreq, areq->assoc, areq->assoclen); seqiv_geniv(ctx, info, req->seq, ivsize); memcpy(req->giv, info, ivsize); err = crypto_aead_encrypt(subreq); if (unlikely(info != areq->iv)) seqiv_aead_complete2(req, err); return err; } static int seqniv_aead_encrypt(struct aead_request *req) { struct crypto_aead *geniv = crypto_aead_reqtfm(req); struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); struct seqniv_request_ctx *rctx = aead_request_ctx(req); struct aead_request *subreq = &rctx->subreq; struct scatterlist *dst; crypto_completion_t compl; void *data; unsigned int ivsize = 8; u8 buf[20] __attribute__ ((aligned(__alignof__(u32)))); int err; if (req->cryptlen < ivsize) return -EINVAL; /* ESP AD is at most 12 bytes (ESN). */ if (req->assoclen > 12) return -EINVAL; aead_request_set_tfm(subreq, ctx->geniv.child); compl = seqniv_aead_encrypt_complete; data = req; if (req->src != req->dst) { struct blkcipher_desc desc = { .tfm = ctx->null, }; err = crypto_blkcipher_encrypt(&desc, req->dst, req->src, req->assoclen + req->cryptlen); if (err) return err; } dst = scatterwalk_ffwd(rctx->dst, req->dst, ivsize); aead_request_set_callback(subreq, req->base.flags, compl, data); aead_request_set_crypt(subreq, dst, dst, req->cryptlen - ivsize, req->iv); aead_request_set_ad(subreq, req->assoclen); memcpy(buf, req->iv, ivsize); crypto_xor(buf, ctx->salt, ivsize); memcpy(req->iv, buf, ivsize); /* Swap order of IV and ESP AD for ICV generation. */ scatterwalk_map_and_copy(buf + ivsize, req->dst, 0, req->assoclen, 0); scatterwalk_map_and_copy(buf, req->dst, 0, req->assoclen + ivsize, 1); err = crypto_aead_encrypt(subreq); seqniv_aead_encrypt_complete2(req, err); return err; } static int seqiv_aead_encrypt(struct aead_request *req) { struct crypto_aead *geniv = crypto_aead_reqtfm(req); struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); struct aead_request *subreq = aead_request_ctx(req); crypto_completion_t compl; void *data; u8 *info; unsigned int ivsize = 8; int err; if (req->cryptlen < ivsize) return -EINVAL; aead_request_set_tfm(subreq, ctx->geniv.child); compl = req->base.complete; data = req->base.data; info = req->iv; if (req->src != req->dst) { struct blkcipher_desc desc = { .tfm = ctx->null, }; err = crypto_blkcipher_encrypt(&desc, req->dst, req->src, req->assoclen + req->cryptlen); if (err) return err; } if (unlikely(!IS_ALIGNED((unsigned long)info, crypto_aead_alignmask(geniv) + 1))) { info = kmalloc(ivsize, req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: GFP_ATOMIC); if (!info) return -ENOMEM; memcpy(info, req->iv, ivsize); compl = seqiv_aead_encrypt_complete; data = req; } aead_request_set_callback(subreq, req->base.flags, compl, data); aead_request_set_crypt(subreq, req->dst, req->dst, req->cryptlen - ivsize, info); aead_request_set_ad(subreq, req->assoclen + ivsize); crypto_xor(info, ctx->salt, ivsize); scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1); err = crypto_aead_encrypt(subreq); if (unlikely(info != req->iv)) seqiv_aead_encrypt_complete2(req, err); return err; } static int seqniv_aead_decrypt(struct aead_request *req) { struct crypto_aead *geniv = crypto_aead_reqtfm(req); struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); struct seqniv_request_ctx *rctx = aead_request_ctx(req); struct aead_request *subreq = &rctx->subreq; struct scatterlist *dst; crypto_completion_t compl; void *data; unsigned int ivsize = 8; u8 buf[20]; int err; if (req->cryptlen < ivsize + crypto_aead_authsize(geniv)) return -EINVAL; aead_request_set_tfm(subreq, ctx->geniv.child); compl = req->base.complete; data = req->base.data; if (req->assoclen > 12) return -EINVAL; else if (req->assoclen > 8) { compl = seqniv_aead_decrypt_complete; data = req; } if (req->src != req->dst) { struct blkcipher_desc desc = { .tfm = ctx->null, }; err = crypto_blkcipher_encrypt(&desc, req->dst, req->src, req->assoclen + req->cryptlen); if (err) return err; } /* Move ESP AD forward for ICV generation. */ scatterwalk_map_and_copy(buf, req->dst, 0, req->assoclen + ivsize, 0); memcpy(req->iv, buf + req->assoclen, ivsize); scatterwalk_map_and_copy(buf, req->dst, ivsize, req->assoclen, 1); dst = scatterwalk_ffwd(rctx->dst, req->dst, ivsize); aead_request_set_callback(subreq, req->base.flags, compl, data); aead_request_set_crypt(subreq, dst, dst, req->cryptlen - ivsize, req->iv); aead_request_set_ad(subreq, req->assoclen); err = crypto_aead_decrypt(subreq); if (req->assoclen > 8) seqniv_aead_decrypt_complete2(req, err); return err; } static int seqiv_aead_decrypt(struct aead_request *req) { struct crypto_aead *geniv = crypto_aead_reqtfm(req); struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); struct aead_request *subreq = aead_request_ctx(req); crypto_completion_t compl; void *data; unsigned int ivsize = 8; if (req->cryptlen < ivsize + crypto_aead_authsize(geniv)) return -EINVAL; aead_request_set_tfm(subreq, ctx->geniv.child); compl = req->base.complete; data = req->base.data; aead_request_set_callback(subreq, req->base.flags, compl, data); aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen - ivsize, req->iv); aead_request_set_ad(subreq, req->assoclen + ivsize); scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0); if (req->src != req->dst) scatterwalk_map_and_copy(req->iv, req->dst, req->assoclen, ivsize, 1); return crypto_aead_decrypt(subreq); } static int seqiv_init(struct crypto_tfm *tfm) { struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm); struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); int err; spin_lock_init(&ctx->lock); tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request); err = 0; if (!crypto_get_default_rng()) { crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt; err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, crypto_ablkcipher_ivsize(geniv)); crypto_put_default_rng(); } return err ?: skcipher_geniv_init(tfm); } static int seqiv_old_aead_init(struct crypto_tfm *tfm) { struct crypto_aead *geniv = __crypto_aead_cast(tfm); struct seqiv_ctx *ctx = crypto_aead_ctx(geniv); int err; spin_lock_init(&ctx->lock); crypto_aead_set_reqsize(__crypto_aead_cast(tfm), sizeof(struct aead_request)); err = 0; if (!crypto_get_default_rng()) { geniv->givencrypt = seqiv_aead_givencrypt; err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, crypto_aead_ivsize(geniv)); crypto_put_default_rng(); } return err ?: aead_geniv_init(tfm); } static int seqiv_aead_init_common(struct crypto_tfm *tfm, unsigned int reqsize) { struct crypto_aead *geniv = __crypto_aead_cast(tfm); struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); int err; spin_lock_init(&ctx->geniv.lock); crypto_aead_set_reqsize(geniv, sizeof(struct aead_request)); err = crypto_get_default_rng(); if (err) goto out; err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, crypto_aead_ivsize(geniv)); crypto_put_default_rng(); if (err) goto out; ctx->null = crypto_get_default_null_skcipher(); err = PTR_ERR(ctx->null); if (IS_ERR(ctx->null)) goto out; err = aead_geniv_init(tfm); if (err) goto drop_null; ctx->geniv.child = geniv->child; geniv->child = geniv; out: return err; drop_null: crypto_put_default_null_skcipher(); goto out; } static int seqiv_aead_init(struct crypto_tfm *tfm) { return seqiv_aead_init_common(tfm, sizeof(struct aead_request)); } static int seqniv_aead_init(struct crypto_tfm *tfm) { return seqiv_aead_init_common(tfm, sizeof(struct seqniv_request_ctx)); } static void seqiv_aead_exit(struct crypto_tfm *tfm) { struct seqiv_aead_ctx *ctx = crypto_tfm_ctx(tfm); crypto_free_aead(ctx->geniv.child); crypto_put_default_null_skcipher(); } static int seqiv_ablkcipher_create(struct crypto_template *tmpl, struct rtattr **tb) { struct crypto_instance *inst; int err; inst = skcipher_geniv_alloc(tmpl, tb, 0, 0); if (IS_ERR(inst)) return PTR_ERR(inst); err = -EINVAL; if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64)) goto free_inst; inst->alg.cra_init = seqiv_init; inst->alg.cra_exit = skcipher_geniv_exit; inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize; inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx); inst->alg.cra_alignmask |= __alignof__(u32) - 1; err = crypto_register_instance(tmpl, inst); if (err) goto free_inst; out: return err; free_inst: skcipher_geniv_free(inst); goto out; } static int seqiv_old_aead_create(struct crypto_template *tmpl, struct aead_instance *aead) { struct crypto_instance *inst = aead_crypto_instance(aead); int err = -EINVAL; if (inst->alg.cra_aead.ivsize < sizeof(u64)) goto free_inst; inst->alg.cra_init = seqiv_old_aead_init; inst->alg.cra_exit = aead_geniv_exit; inst->alg.cra_ctxsize = inst->alg.cra_aead.ivsize; inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx); err = crypto_register_instance(tmpl, inst); if (err) goto free_inst; out: return err; free_inst: aead_geniv_free(aead); goto out; } static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb) { struct aead_instance *inst; struct crypto_aead_spawn *spawn; struct aead_alg *alg; int err; inst = aead_geniv_alloc(tmpl, tb, 0, 0); if (IS_ERR(inst)) return PTR_ERR(inst); inst->alg.base.cra_alignmask |= __alignof__(u32) - 1; if (inst->alg.base.cra_aead.encrypt) return seqiv_old_aead_create(tmpl, inst); spawn = aead_instance_ctx(inst); alg = crypto_spawn_aead_alg(spawn); if (alg->base.cra_aead.encrypt) goto done; err = -EINVAL; if (inst->alg.ivsize != sizeof(u64)) goto free_inst; inst->alg.encrypt = seqiv_aead_encrypt; inst->alg.decrypt = seqiv_aead_decrypt; inst->alg.base.cra_init = seqiv_aead_init; inst->alg.base.cra_exit = seqiv_aead_exit; inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx); inst->alg.base.cra_ctxsize += inst->alg.base.cra_aead.ivsize; done: err = aead_register_instance(tmpl, inst); if (err) goto free_inst; out: return err; free_inst: aead_geniv_free(inst); goto out; } static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb) { struct crypto_attr_type *algt; int err; algt = crypto_get_attr_type(tb); if (IS_ERR(algt)) return PTR_ERR(algt); if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) err = seqiv_ablkcipher_create(tmpl, tb); else err = seqiv_aead_create(tmpl, tb); return err; } static int seqniv_create(struct crypto_template *tmpl, struct rtattr **tb) { struct aead_instance *inst; struct crypto_aead_spawn *spawn; struct aead_alg *alg; int err; inst = aead_geniv_alloc(tmpl, tb, 0, 0); err = PTR_ERR(inst); if (IS_ERR(inst)) goto out; spawn = aead_instance_ctx(inst); alg = crypto_spawn_aead_alg(spawn); if (alg->base.cra_aead.encrypt) goto done; err = -EINVAL; if (inst->alg.ivsize != sizeof(u64)) goto free_inst; inst->alg.encrypt = seqniv_aead_encrypt; inst->alg.decrypt = seqniv_aead_decrypt; inst->alg.base.cra_init = seqniv_aead_init; inst->alg.base.cra_exit = seqiv_aead_exit; inst->alg.base.cra_alignmask |= __alignof__(u32) - 1; inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx); inst->alg.base.cra_ctxsize += inst->alg.ivsize; done: err = aead_register_instance(tmpl, inst); if (err) goto free_inst; out: return err; free_inst: aead_geniv_free(inst); goto out; } static void seqiv_free(struct crypto_instance *inst) { if ((inst->alg.cra_flags ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) skcipher_geniv_free(inst); else aead_geniv_free(aead_instance(inst)); } static struct crypto_template seqiv_tmpl = { .name = "seqiv", .create = seqiv_create, .free = seqiv_free, .module = THIS_MODULE, }; static struct crypto_template seqniv_tmpl = { .name = "seqniv", .create = seqniv_create, .free = seqiv_free, .module = THIS_MODULE, }; static int __init seqiv_module_init(void) { int err; err = crypto_register_template(&seqiv_tmpl); if (err) goto out; err = crypto_register_template(&seqniv_tmpl); if (err) goto out_undo_niv; out: return err; out_undo_niv: crypto_unregister_template(&seqiv_tmpl); goto out; } static void __exit seqiv_module_exit(void) { crypto_unregister_template(&seqniv_tmpl); crypto_unregister_template(&seqiv_tmpl); } module_init(seqiv_module_init); module_exit(seqiv_module_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Sequence Number IV Generator"); MODULE_ALIAS_CRYPTO("seqiv"); MODULE_ALIAS_CRYPTO("seqniv");