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-rw-r--r--crypto/Makefile1
-rw-r--r--crypto/eseqiv.c264
2 files changed, 265 insertions, 0 deletions
diff --git a/crypto/Makefile b/crypto/Makefile
index 4b2e0c387cc..968b796d9e6 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -14,6 +14,7 @@ crypto_blkcipher-objs := ablkcipher.o
crypto_blkcipher-objs += blkcipher.o
obj-$(CONFIG_CRYPTO_BLKCIPHER) += crypto_blkcipher.o
obj-$(CONFIG_CRYPTO_BLKCIPHER) += chainiv.o
+obj-$(CONFIG_CRYPTO_BLKCIPHER) += eseqiv.o
crypto_hash-objs := hash.o
obj-$(CONFIG_CRYPTO_HASH) += crypto_hash.o
diff --git a/crypto/eseqiv.c b/crypto/eseqiv.c
new file mode 100644
index 00000000000..eb90d27ae11
--- /dev/null
+++ b/crypto/eseqiv.c
@@ -0,0 +1,264 @@
+/*
+ * eseqiv: Encrypted Sequence Number 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.
+ *
+ * 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/skcipher.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/random.h>
+#include <linux/scatterlist.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+struct eseqiv_request_ctx {
+ struct scatterlist src[2];
+ struct scatterlist dst[2];
+ char tail[];
+};
+
+struct eseqiv_ctx {
+ spinlock_t lock;
+ unsigned int reqoff;
+ char salt[];
+};
+
+static void eseqiv_complete2(struct skcipher_givcrypt_request *req)
+{
+ struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
+ struct eseqiv_request_ctx *reqctx = skcipher_givcrypt_reqctx(req);
+
+ memcpy(req->giv, PTR_ALIGN((u8 *)reqctx->tail,
+ crypto_ablkcipher_alignmask(geniv) + 1),
+ crypto_ablkcipher_ivsize(geniv));
+}
+
+static void eseqiv_complete(struct crypto_async_request *base, int err)
+{
+ struct skcipher_givcrypt_request *req = base->data;
+
+ if (err)
+ goto out;
+
+ eseqiv_complete2(req);
+
+out:
+ skcipher_givcrypt_complete(req, err);
+}
+
+static void eseqiv_chain(struct scatterlist *head, struct scatterlist *sg,
+ int chain)
+{
+ if (chain) {
+ head->length += sg->length;
+ sg = scatterwalk_sg_next(sg);
+ }
+
+ if (sg)
+ scatterwalk_sg_chain(head, 2, sg);
+ else
+ sg_mark_end(head);
+}
+
+static int eseqiv_givencrypt(struct skcipher_givcrypt_request *req)
+{
+ struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
+ struct eseqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
+ struct eseqiv_request_ctx *reqctx = skcipher_givcrypt_reqctx(req);
+ struct ablkcipher_request *subreq;
+ crypto_completion_t complete;
+ void *data;
+ struct scatterlist *osrc, *odst;
+ struct scatterlist *dst;
+ struct page *srcp;
+ struct page *dstp;
+ u8 *giv;
+ u8 *vsrc;
+ u8 *vdst;
+ __be64 seq;
+ unsigned int ivsize;
+ unsigned int len;
+ int err;
+
+ subreq = (void *)(reqctx->tail + ctx->reqoff);
+ ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv));
+
+ giv = req->giv;
+ complete = req->creq.base.complete;
+ data = req->creq.base.data;
+
+ osrc = req->creq.src;
+ odst = req->creq.dst;
+ srcp = sg_page(osrc);
+ dstp = sg_page(odst);
+ vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + osrc->offset;
+ vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + odst->offset;
+
+ ivsize = crypto_ablkcipher_ivsize(geniv);
+
+ if (vsrc != giv + ivsize && vdst != giv + ivsize) {
+ giv = PTR_ALIGN((u8 *)reqctx->tail,
+ crypto_ablkcipher_alignmask(geniv) + 1);
+ complete = eseqiv_complete;
+ data = req;
+ }
+
+ ablkcipher_request_set_callback(subreq, req->creq.base.flags, complete,
+ data);
+
+ sg_init_table(reqctx->src, 2);
+ sg_set_buf(reqctx->src, giv, ivsize);
+ eseqiv_chain(reqctx->src, osrc, vsrc == giv + ivsize);
+
+ dst = reqctx->src;
+ if (osrc != odst) {
+ sg_init_table(reqctx->dst, 2);
+ sg_set_buf(reqctx->dst, giv, ivsize);
+ eseqiv_chain(reqctx->dst, odst, vdst == giv + ivsize);
+
+ dst = reqctx->dst;
+ }
+
+ ablkcipher_request_set_crypt(subreq, reqctx->src, dst,
+ req->creq.nbytes, req->creq.info);
+
+ memcpy(req->creq.info, ctx->salt, ivsize);
+
+ len = ivsize;
+ if (ivsize > sizeof(u64)) {
+ memset(req->giv, 0, ivsize - sizeof(u64));
+ len = sizeof(u64);
+ }
+ seq = cpu_to_be64(req->seq);
+ memcpy(req->giv + ivsize - len, &seq, len);
+
+ err = crypto_ablkcipher_encrypt(subreq);
+ if (err)
+ goto out;
+
+ eseqiv_complete2(req);
+
+out:
+ return err;
+}
+
+static int eseqiv_givencrypt_first(struct skcipher_givcrypt_request *req)
+{
+ struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
+ struct eseqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
+
+ spin_lock_bh(&ctx->lock);
+ if (crypto_ablkcipher_crt(geniv)->givencrypt != eseqiv_givencrypt_first)
+ goto unlock;
+
+ crypto_ablkcipher_crt(geniv)->givencrypt = eseqiv_givencrypt;
+ get_random_bytes(ctx->salt, crypto_ablkcipher_ivsize(geniv));
+
+unlock:
+ spin_unlock_bh(&ctx->lock);
+
+ return eseqiv_givencrypt(req);
+}
+
+static int eseqiv_init(struct crypto_tfm *tfm)
+{
+ struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
+ struct eseqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
+ unsigned long alignmask;
+ unsigned int reqsize;
+
+ spin_lock_init(&ctx->lock);
+
+ alignmask = crypto_tfm_ctx_alignment() - 1;
+ reqsize = sizeof(struct eseqiv_request_ctx);
+
+ if (alignmask & reqsize) {
+ alignmask &= reqsize;
+ alignmask--;
+ }
+
+ alignmask = ~alignmask;
+ alignmask &= crypto_ablkcipher_alignmask(geniv);
+
+ reqsize += alignmask;
+ reqsize += crypto_ablkcipher_ivsize(geniv);
+ reqsize = ALIGN(reqsize, crypto_tfm_ctx_alignment());
+
+ ctx->reqoff = reqsize - sizeof(struct eseqiv_request_ctx);
+
+ tfm->crt_ablkcipher.reqsize = reqsize +
+ sizeof(struct ablkcipher_request);
+
+ return skcipher_geniv_init(tfm);
+}
+
+static struct crypto_template eseqiv_tmpl;
+
+static struct crypto_instance *eseqiv_alloc(struct rtattr **tb)
+{
+ struct crypto_instance *inst;
+ int err;
+
+ inst = skcipher_geniv_alloc(&eseqiv_tmpl, tb, 0, 0);
+ if (IS_ERR(inst))
+ goto out;
+
+ err = -EINVAL;
+ if (inst->alg.cra_ablkcipher.ivsize != inst->alg.cra_blocksize)
+ goto free_inst;
+
+ inst->alg.cra_ablkcipher.givencrypt = eseqiv_givencrypt_first;
+
+ inst->alg.cra_init = eseqiv_init;
+ inst->alg.cra_exit = skcipher_geniv_exit;
+
+ inst->alg.cra_ctxsize = sizeof(struct eseqiv_ctx);
+ inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize;
+
+out:
+ return inst;
+
+free_inst:
+ skcipher_geniv_free(inst);
+ inst = ERR_PTR(err);
+ goto out;
+}
+
+static struct crypto_template eseqiv_tmpl = {
+ .name = "eseqiv",
+ .alloc = eseqiv_alloc,
+ .free = skcipher_geniv_free,
+ .module = THIS_MODULE,
+};
+
+static int __init eseqiv_module_init(void)
+{
+ return crypto_register_template(&eseqiv_tmpl);
+}
+
+static void __exit eseqiv_module_exit(void)
+{
+ crypto_unregister_template(&eseqiv_tmpl);
+}
+
+module_init(eseqiv_module_init);
+module_exit(eseqiv_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Encrypted Sequence Number IV Generator");