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;