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-rw-r--r--crypto/echainiv.c115
1 files changed, 24 insertions, 91 deletions
diff --git a/crypto/echainiv.c b/crypto/echainiv.c
index 1b01fe98e91f..e3d889b122e0 100644
--- a/crypto/echainiv.c
+++ b/crypto/echainiv.c
@@ -1,8 +1,8 @@
/*
* 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
+ * This generator generates an IV based on a sequence number by multiplying
+ * 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.
*
@@ -24,81 +24,17 @@
#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/slab.h>
#include <linux/string.h>
-#define MAX_IV_SIZE 16
-
-static DEFINE_PER_CPU(u32 [MAX_IV_SIZE / sizeof(u32)], echainiv_iv);
-
-/* We don't care if we get preempted and read/write IVs from the next CPU. */
-static 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++;
- }
-}
-
-static 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_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(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
struct aead_request *subreq = aead_request_ctx(req);
- crypto_completion_t compl;
- void *data;
+ __be64 nseqno;
+ u64 seqno;
u8 *info;
unsigned int ivsize = crypto_aead_ivsize(geniv);
int err;
@@ -108,8 +44,6 @@ static int echainiv_encrypt(struct aead_request *req)
aead_request_set_tfm(subreq, ctx->child);
- compl = echainiv_encrypt_complete;
- data = req;
info = req->iv;
if (req->src != req->dst) {
@@ -127,29 +61,30 @@ static int echainiv_encrypt(struct aead_request *req)
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_callback(subreq, req->base.flags,
+ req->base.complete, req->base.data);
aead_request_set_crypt(subreq, req->dst, req->dst,
req->cryptlen, info);
aead_request_set_ad(subreq, req->assoclen);
- crypto_xor(info, ctx->salt, ivsize);
+ memcpy(&nseqno, info + ivsize - 8, 8);
+ seqno = be64_to_cpu(nseqno);
+ memset(info, 0, 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;
+ do {
+ u64 a;
+
+ memcpy(&a, ctx->salt + ivsize - 8, 8);
+
+ a |= 1;
+ a *= seqno;
+
+ memcpy(info + ivsize - 8, &a, 8);
+ } while ((ivsize -= 8));
+
+ return crypto_aead_encrypt(subreq);
}
static int echainiv_decrypt(struct aead_request *req)
@@ -196,8 +131,7 @@ static int echainiv_aead_create(struct crypto_template *tmpl,
alg = crypto_spawn_aead_alg(spawn);
err = -EINVAL;
- if (inst->alg.ivsize & (sizeof(u32) - 1) ||
- inst->alg.ivsize > MAX_IV_SIZE)
+ if (inst->alg.ivsize & (sizeof(u64) - 1) || !inst->alg.ivsize)
goto free_inst;
inst->alg.encrypt = echainiv_encrypt;
@@ -206,7 +140,6 @@ static int echainiv_aead_create(struct crypto_template *tmpl,
inst->alg.init = aead_init_geniv;
inst->alg.exit = aead_exit_geniv;
- inst->alg.base.cra_alignmask |= __alignof__(u32) - 1;
inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
inst->alg.base.cra_ctxsize += inst->alg.ivsize;