From 38b4d7aab1aba361528309d8d60c094d9299f4da Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Sun, 6 Apr 2014 17:23:55 +0200
Subject: [PATCH] crypto/modes: strict aliasing fixes from master.

---
 crypto/modes/cbc128.c | 25 ++++++++++++++-----------
 crypto/modes/cts128.c | 14 ++++----------
 2 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/crypto/modes/cbc128.c b/crypto/modes/cbc128.c
index 8f8bd563b9..64b2477886 100644
--- a/crypto/modes/cbc128.c
+++ b/crypto/modes/cbc128.c
@@ -121,7 +121,7 @@ void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 			unsigned char ivec[16], block128_f block)
 {
 	size_t n;
-	union { size_t align; unsigned char c[16]; } tmp;
+	union { size_t t[16/sizeof(size_t)]; unsigned char c[16]; } tmp;
 
 	assert(in && out && key && ivec);
 
@@ -141,11 +141,13 @@ void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 				out += 16;
 			}
 		}
-		else {
+		else  if (16%sizeof(size_t) == 0) { /* always true */
 			while (len>=16) {
+				size_t *out_t=(size_t *)out, *iv_t=(size_t *)iv;
+
 				(*block)(in, out, key);
-				for(n=0; n<16; n+=sizeof(size_t))
-					*(size_t *)(out+n) ^= *(size_t *)(iv+n);
+				for(n=0; n<16/sizeof(size_t); n++)
+					out_t[n] ^= iv_t[n];
 				iv = in;
 				len -= 16;
 				in  += 16;
@@ -169,15 +171,16 @@ void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 				out += 16;
 			}
 		}
-		else {
-			size_t c;
+		else if (16%sizeof(size_t) == 0) { /* always true */
 			while (len>=16) {
+				size_t c, *out_t=(size_t *)out, *ivec_t=(size_t *)ivec;
+				const size_t *in_t=(const size_t *)in;
+
 				(*block)(in, tmp.c, key);
-				for(n=0; n<16; n+=sizeof(size_t)) {
-					c = *(size_t *)(in+n);
-					*(size_t *)(out+n) =
-					*(size_t *)(tmp.c+n) ^ *(size_t *)(ivec+n);
-					*(size_t *)(ivec+n) = c;
+				for(n=0; n<16/sizeof(size_t); n++) {
+					c = in_t[n];
+					out_t[n] = tmp.t[n] ^ ivec_t[n];
+					ivec_t[n] = c;
 				}
 				len -= 16;
 				in  += 16;
diff --git a/crypto/modes/cts128.c b/crypto/modes/cts128.c
index e0430f9fdc..4a087a03af 100644
--- a/crypto/modes/cts128.c
+++ b/crypto/modes/cts128.c
@@ -78,12 +78,8 @@ size_t CRYPTO_cts128_encrypt(const unsigned char *in, unsigned char *out,
 	(*cbc)(in,out-16,residue,key,ivec,1);
 	memcpy(out,tmp.c,residue);
 #else
-	{
-	size_t n;
-	for (n=0; n<16; n+=sizeof(size_t))
-		*(size_t *)(tmp.c+n) = 0;
+	memset(tmp.c,0,sizeof(tmp));
 	memcpy(tmp.c,in,residue);
-	}
 	memcpy(out,out-16,residue);
 	(*cbc)(tmp.c,out-16,16,key,ivec,1);
 #endif
@@ -112,8 +108,7 @@ size_t CRYPTO_cts128_decrypt_block(const unsigned char *in, unsigned char *out,
 
 	(*block)(in,tmp.c+16,key);
 
-	for (n=0; n<16; n+=sizeof(size_t))
-		*(size_t *)(tmp.c+n) = *(size_t *)(tmp.c+16+n);
+	memcpy(tmp.c,tmp.c+16,16);
 	memcpy(tmp.c,in+16,residue);
 	(*block)(tmp.c,tmp.c,key);
 
@@ -131,7 +126,7 @@ size_t CRYPTO_cts128_decrypt_block(const unsigned char *in, unsigned char *out,
 size_t CRYPTO_cts128_decrypt(const unsigned char *in, unsigned char *out,
 			size_t len, const void *key,
 			unsigned char ivec[16], cbc128_f cbc)
-{	size_t residue, n;
+{	size_t residue;
 	union { size_t align; unsigned char c[32]; } tmp;
 
 	assert (in && out && key && ivec);
@@ -148,8 +143,7 @@ size_t CRYPTO_cts128_decrypt(const unsigned char *in, unsigned char *out,
 		out += len;
 	}
 
-	for (n=16; n<32; n+=sizeof(size_t))
-		*(size_t *)(tmp.c+n) = 0;
+	memset(tmp.c,0,sizeof(tmp));
 	/* this places in[16] at &tmp.c[16] and decrypted block at &tmp.c[0] */
 	(*cbc)(in,tmp.c,16,key,tmp.c+16,0);
 
-- 
2.25.1