--- /dev/null
+/*
+ * echainiv: Encrypted Chain IV Generator
+ *
+ * This generator generates an IV based on a sequence number by xoring it
+ * with a salt and then encrypting it with the same key as used to encrypt
+ * the plain text. This algorithm requires that the block size be equal
+ * to the IV size. It is mainly useful for CBC.
+ *
+ * This generator can only be used by algorithms where authentication
+ * is performed after encryption (i.e., authenc).
+ *
+ * Copyright (c) 2015 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/aead.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/mm.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+#define MAX_IV_SIZE 16
+
+struct echainiv_request_ctx {
+ struct scatterlist src[2];
+ struct scatterlist dst[2];
+ struct scatterlist ivbuf[2];
+ struct scatterlist *ivsg;
+ struct aead_givcrypt_request subreq;
+};
+
+struct echainiv_ctx {
+ struct crypto_aead *child;
+ spinlock_t lock;
+ struct crypto_blkcipher *null;
+ u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
+};
+
+static DEFINE_PER_CPU(u32 [MAX_IV_SIZE / sizeof(u32)], echainiv_iv);
+
+static int echainiv_setkey(struct crypto_aead *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ struct echainiv_ctx *ctx = crypto_aead_ctx(tfm);
+
+ return crypto_aead_setkey(ctx->child, key, keylen);
+}
+
+static int echainiv_setauthsize(struct crypto_aead *tfm,
+ unsigned int authsize)
+{
+ struct echainiv_ctx *ctx = crypto_aead_ctx(tfm);
+
+ return crypto_aead_setauthsize(ctx->child, authsize);
+}
+
+/* We don't care if we get preempted and read/write IVs from the next CPU. */
+void echainiv_read_iv(u8 *dst, unsigned size)
+{
+ u32 *a = (u32 *)dst;
+ u32 __percpu *b = echainiv_iv;
+
+ for (; size >= 4; size -= 4) {
+ *a++ = this_cpu_read(*b);
+ b++;
+ }
+}
+
+void echainiv_write_iv(const u8 *src, unsigned size)
+{
+ const u32 *a = (const u32 *)src;
+ u32 __percpu *b = echainiv_iv;
+
+ for (; size >= 4; size -= 4) {
+ this_cpu_write(*b, *a);
+ a++;
+ b++;
+ }
+}
+
+static void echainiv_encrypt_compat_complete2(struct aead_request *req,
+ int err)
+{
+ struct echainiv_request_ctx *rctx = aead_request_ctx(req);
+ struct aead_givcrypt_request *subreq = &rctx->subreq;
+ struct crypto_aead *geniv;
+
+ if (err == -EINPROGRESS)
+ return;
+
+ if (err)
+ goto out;
+
+ geniv = crypto_aead_reqtfm(req);
+ scatterwalk_map_and_copy(subreq->giv, rctx->ivsg, 0,
+ crypto_aead_ivsize(geniv), 1);
+
+out:
+ kzfree(subreq->giv);
+}
+
+static void echainiv_encrypt_compat_complete(
+ struct crypto_async_request *base, int err)
+{
+ struct aead_request *req = base->data;
+
+ echainiv_encrypt_compat_complete2(req, err);
+ aead_request_complete(req, err);
+}
+
+static void echainiv_encrypt_complete2(struct aead_request *req, int err)
+{
+ struct aead_request *subreq = aead_request_ctx(req);
+ struct crypto_aead *geniv;
+ unsigned int ivsize;
+
+ if (err == -EINPROGRESS)
+ return;
+
+ if (err)
+ goto out;
+
+ geniv = crypto_aead_reqtfm(req);
+ ivsize = crypto_aead_ivsize(geniv);
+
+ echainiv_write_iv(subreq->iv, ivsize);
+
+ if (req->iv != subreq->iv)
+ memcpy(req->iv, subreq->iv, ivsize);
+
+out:
+ if (req->iv != subreq->iv)
+ kzfree(subreq->iv);
+}
+
+static void echainiv_encrypt_complete(struct crypto_async_request *base,
+ int err)
+{
+ struct aead_request *req = base->data;
+
+ echainiv_encrypt_complete2(req, err);
+ aead_request_complete(req, err);
+}
+
+static int echainiv_encrypt_compat(struct aead_request *req)
+{
+ struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ struct echainiv_request_ctx *rctx = aead_request_ctx(req);
+ struct aead_givcrypt_request *subreq = &rctx->subreq;
+ unsigned int ivsize = crypto_aead_ivsize(geniv);
+ crypto_completion_t compl;
+ void *data;
+ u8 *info;
+ __be64 seq;
+ int err;
+
+ compl = req->base.complete;
+ data = req->base.data;
+
+ rctx->ivsg = scatterwalk_ffwd(rctx->ivbuf, req->dst, req->assoclen);
+ info = PageHighMem(sg_page(rctx->ivsg)) ? NULL : sg_virt(rctx->ivsg);
+
+ if (!info) {
+ info = kmalloc(ivsize, req->base.flags &
+ CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
+ GFP_ATOMIC);
+ if (!info)
+ return -ENOMEM;
+
+ compl = echainiv_encrypt_compat_complete;
+ data = req;
+ }
+
+ memcpy(&seq, req->iv + ivsize - sizeof(seq), sizeof(seq));
+
+ aead_givcrypt_set_tfm(subreq, ctx->child);
+ aead_givcrypt_set_callback(subreq, req->base.flags,
+ req->base.complete, req->base.data);
+ aead_givcrypt_set_crypt(subreq,
+ scatterwalk_ffwd(rctx->src, req->src,
+ req->assoclen + ivsize),
+ scatterwalk_ffwd(rctx->dst, rctx->ivsg,
+ ivsize),
+ req->cryptlen - ivsize, req->iv);
+ aead_givcrypt_set_assoc(subreq, req->src, req->assoclen);
+ aead_givcrypt_set_giv(subreq, info, be64_to_cpu(seq));
+
+ err = crypto_aead_givencrypt(subreq);
+ if (unlikely(PageHighMem(sg_page(rctx->ivsg))))
+ echainiv_encrypt_compat_complete2(req, err);
+ return err;
+}
+
+static int echainiv_encrypt(struct aead_request *req)
+{
+ struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+ struct echainiv_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;
+ int err;
+
+ aead_request_set_tfm(subreq, ctx->child);
+
+ compl = echainiv_encrypt_complete;
+ data = req;
+ info = req->iv;
+
+ ivsize = crypto_aead_ivsize(geniv);
+
+ if (req->src != req->dst) {
+ struct scatterlist src[2];
+ struct scatterlist dst[2];
+ struct blkcipher_desc desc = {
+ .tfm = ctx->null,
+ };
+
+ err = crypto_blkcipher_encrypt(
+ &desc,
+ scatterwalk_ffwd(dst, req->dst,
+ req->assoclen + ivsize),
+ scatterwalk_ffwd(src, req->src,
+ req->assoclen + ivsize),
+ req->cryptlen - ivsize);
+ 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);
+ }
+
+ 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, 0);
+
+ crypto_xor(info, ctx->salt, ivsize);
+ scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
+ echainiv_read_iv(info, ivsize);
+
+ err = crypto_aead_encrypt(subreq);
+ echainiv_encrypt_complete2(req, err);
+ return err;
+}
+
+static int echainiv_decrypt_compat(struct aead_request *req)
+{
+ struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ struct aead_request *subreq = aead_request_ctx(req);
+ crypto_completion_t compl;
+ void *data;
+ unsigned int ivsize;
+
+ aead_request_set_tfm(subreq, ctx->child);
+
+ compl = req->base.complete;
+ data = req->base.data;
+
+ ivsize = crypto_aead_ivsize(geniv);
+
+ 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);
+
+ return crypto_aead_decrypt(subreq);
+}
+
+static int echainiv_decrypt(struct aead_request *req)
+{
+ struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ struct aead_request *subreq = aead_request_ctx(req);
+ crypto_completion_t compl;
+ void *data;
+ unsigned int ivsize;
+
+ aead_request_set_tfm(subreq, ctx->child);
+
+ compl = req->base.complete;
+ data = req->base.data;
+
+ ivsize = crypto_aead_ivsize(geniv);
+
+ 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, 0);
+
+ 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 echainiv_encrypt_compat_first(struct aead_request *req)
+{
+ struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ int err = 0;
+
+ spin_lock_bh(&ctx->lock);
+ if (geniv->encrypt != echainiv_encrypt_compat_first)
+ goto unlock;
+
+ geniv->encrypt = echainiv_encrypt_compat;
+ err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
+ crypto_aead_ivsize(geniv));
+
+unlock:
+ spin_unlock_bh(&ctx->lock);
+
+ if (err)
+ return err;
+
+ return echainiv_encrypt_compat(req);
+}
+
+static int echainiv_encrypt_first(struct aead_request *req)
+{
+ struct crypto_aead *geniv = crypto_aead_reqtfm(req);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ int err = 0;
+
+ spin_lock_bh(&ctx->lock);
+ if (geniv->encrypt != echainiv_encrypt_first)
+ goto unlock;
+
+ geniv->encrypt = echainiv_encrypt;
+ err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
+ crypto_aead_ivsize(geniv));
+
+unlock:
+ spin_unlock_bh(&ctx->lock);
+
+ if (err)
+ return err;
+
+ return echainiv_encrypt(req);
+}
+
+static int echainiv_compat_init(struct crypto_tfm *tfm)
+{
+ struct crypto_aead *geniv = __crypto_aead_cast(tfm);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ int err;
+
+ spin_lock_init(&ctx->lock);
+
+ crypto_aead_set_reqsize(geniv, sizeof(struct echainiv_request_ctx));
+
+ err = aead_geniv_init(tfm);
+
+ ctx->child = geniv->child;
+ geniv->child = geniv;
+
+ return err;
+}
+
+static int echainiv_init(struct crypto_tfm *tfm)
+{
+ struct crypto_aead *geniv = __crypto_aead_cast(tfm);
+ struct echainiv_ctx *ctx = crypto_aead_ctx(geniv);
+ int err;
+
+ spin_lock_init(&ctx->lock);
+
+ crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
+
+ 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->child = geniv->child;
+ geniv->child = geniv;
+
+out:
+ return err;
+
+drop_null:
+ crypto_put_default_null_skcipher();
+ goto out;
+}
+
+static void echainiv_compat_exit(struct crypto_tfm *tfm)
+{
+ struct echainiv_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_aead(ctx->child);
+}
+
+static void echainiv_exit(struct crypto_tfm *tfm)
+{
+ struct echainiv_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_aead(ctx->child);
+ crypto_put_default_null_skcipher();
+}
+
+static struct crypto_template echainiv_tmpl;
+
+static struct crypto_instance *echainiv_aead_alloc(struct rtattr **tb)
+{
+ struct aead_instance *inst;
+ struct crypto_aead_spawn *spawn;
+ struct aead_alg *alg;
+
+ inst = aead_geniv_alloc(&echainiv_tmpl, tb, 0, 0);
+
+ if (IS_ERR(inst))
+ goto out;
+
+ if (inst->alg.ivsize < sizeof(u64) ||
+ inst->alg.ivsize & (sizeof(u32) - 1) ||
+ inst->alg.ivsize > MAX_IV_SIZE) {
+ aead_geniv_free(inst);
+ inst = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ spawn = aead_instance_ctx(inst);
+ alg = crypto_spawn_aead_alg(spawn);
+
+ inst->alg.setkey = echainiv_setkey;
+ inst->alg.setauthsize = echainiv_setauthsize;
+ inst->alg.encrypt = echainiv_encrypt_first;
+ inst->alg.decrypt = echainiv_decrypt;
+
+ inst->alg.base.cra_init = echainiv_init;
+ inst->alg.base.cra_exit = echainiv_exit;
+
+ inst->alg.base.cra_alignmask |= __alignof__(u32) - 1;
+ inst->alg.base.cra_ctxsize = sizeof(struct echainiv_ctx);
+ inst->alg.base.cra_ctxsize += inst->alg.base.cra_aead.ivsize;
+
+ if (alg->base.cra_aead.encrypt) {
+ inst->alg.encrypt = echainiv_encrypt_compat_first;
+ inst->alg.decrypt = echainiv_decrypt_compat;
+
+ inst->alg.base.cra_init = echainiv_compat_init;
+ inst->alg.base.cra_exit = echainiv_compat_exit;
+ }
+
+out:
+ return aead_crypto_instance(inst);
+}
+
+static struct crypto_instance *echainiv_alloc(struct rtattr **tb)
+{
+ struct crypto_instance *inst;
+ int err;
+
+ err = crypto_get_default_rng();
+ if (err)
+ return ERR_PTR(err);
+
+ inst = echainiv_aead_alloc(tb);
+
+ if (IS_ERR(inst))
+ goto put_rng;
+
+out:
+ return inst;
+
+put_rng:
+ crypto_put_default_rng();
+ goto out;
+}
+
+static void echainiv_free(struct crypto_instance *inst)
+{
+ aead_geniv_free(aead_instance(inst));
+ crypto_put_default_rng();
+}
+
+static struct crypto_template echainiv_tmpl = {
+ .name = "echainiv",
+ .alloc = echainiv_alloc,
+ .free = echainiv_free,
+ .module = THIS_MODULE,
+};
+
+static int __init echainiv_module_init(void)
+{
+ return crypto_register_template(&echainiv_tmpl);
+}
+
+static void __exit echainiv_module_exit(void)
+{
+ crypto_unregister_template(&echainiv_tmpl);
+}
+
+module_init(echainiv_module_init);
+module_exit(echainiv_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Encrypted Chain IV Generator");
+MODULE_ALIAS_CRYPTO("echainiv");
projects / linux-drm-fsl-dcu.git / blobdiff