ctr129.c: fix typo, simplify ctr128_inc and fix "n=0" bug.
authorAndy Polyakov <appro@openssl.org>
Sat, 10 Apr 2010 13:46:53 +0000 (13:46 +0000)
committerAndy Polyakov <appro@openssl.org>
Sat, 10 Apr 2010 13:46:53 +0000 (13:46 +0000)
crypto/modes/ctr128.c

index bd84f41..932037f 100644 (file)
 typedef unsigned int u32;
 typedef unsigned char u8;
 
-# define GETU32(pt) (((u32)(pt)[0] << 24) ^ ((u32)(pt)[1] << 16) ^ ((u32)(pt)[2] <<  8) ^ ((u32)(pt)[3]))
-# define PUTU32(ct, st) { (ct)[0] = (u8)((st) >> 24); (ct)[1] = (u8)((st) >> 16); (ct)[2] = (u8)((st) >>  8); (ct)[3] = (u8)(st); }
-
 #define STRICT_ALIGNMENT
-#if defined(__i386) || defined(__i386__) || \
-    defined(__x86_64) || defined(__x86_64__) || \
-    defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \
-    defined(__s390__) || defined(__s390x__)
+#if defined(__i386)    || defined(__i386__)    || \
+    defined(__x86_64)  || defined(__x86_64__)  || \
+    defined(_M_IX86)   || defined(_M_AMD64)    || defined(_M_X64) || \
+    defined(__s390__)  || defined(__s390x__)
 #  undef STRICT_ALIGNMENT
 #endif
 
@@ -77,18 +74,19 @@ typedef unsigned char u8;
 
 /* increment counter (128-bit int) by 1 */
 static void ctr128_inc(unsigned char *counter) {
-       u32 c,n=16;
+       u32 n=16;
+       u8  c;
 
        do {
-               n -= 4;
-               c = GETU32(counter+n);
-               ++c;    c &= 0xFFFFFFFF;
-               PUTU32(counter + n, c);
+               --n;
+               c = counter[n];
+               ++c;
+               counter[n] = c;
                if (c) return;
        } while (n);
 }
 
-#if !defined(OPENSSL_SMALL_FOORPRINT)
+#if !defined(OPENSSL_SMALL_FOOTPRINT)
 static void ctr128_inc_aligned(unsigned char *counter) {
        size_t *data,c,n;
        const union { long one; char little; } is_endian = {1};
@@ -151,14 +149,14 @@ void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out,
                while (len>=16) {
                        (*block)(ivec, ecount_buf, key);
                        ctr128_inc_aligned(ivec);
-                       for (n=0; n<16; n+=sizeof(size_t))
+                       for (; n<16; n+=sizeof(size_t))
                                *(size_t *)(out+n) =
                                *(size_t *)(in+n) ^ *(size_t *)(ecount_buf+n);
                        len -= 16;
                        out += 16;
                        in  += 16;
+                       n = 0;
                }
-               n = 0;
                if (len) {
                        (*block)(ivec, ecount_buf, key);
                        ctr128_inc_aligned(ivec);