*
*/
-#include "modes.h"
+#include <openssl/crypto.h>
+#include "modes_lcl.h"
#include <string.h>
#ifndef MODES_DEBUG
#endif
#include <assert.h>
-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__)
-# undef STRICT_ALIGNMENT
-#endif
-
/* NOTE: the IV/counter CTR mode is big-endian. The code itself
* is endian-neutral. */
/* 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};
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);
*num=n;
}
+
+/* increment upper 96 bits of 128-bit counter by 1 */
+static void ctr96_inc(unsigned char *counter) {
+ u32 n=12;
+ u8 c;
+
+ do {
+ --n;
+ c = counter[n];
+ ++c;
+ counter[n] = c;
+ if (c) return;
+ } while (n);
+}
+
+void CRYPTO_ctr128_encrypt_ctr32(const unsigned char *in, unsigned char *out,
+ size_t len, const void *key,
+ unsigned char ivec[16], unsigned char ecount_buf[16],
+ unsigned int *num, ctr128_f func)
+{
+ unsigned int n,ctr32;
+
+ assert(in && out && key && ecount_buf && num);
+ assert(*num < 16);
+
+ n = *num;
+
+ while (n && len) {
+ *(out++) = *(in++) ^ ecount_buf[n];
+ --len;
+ n = (n+1) % 16;
+ }
+
+ ctr32 = GETU32(ivec+12);
+ while (len>=16) {
+ size_t blocks = len/16;
+ /*
+ * 1<<28 is just a not-so-small yet not-so-large number...
+ * Below condition is practically never met, but it has to
+ * be checked for code correctness.
+ */
+ if (sizeof(size_t)>sizeof(unsigned int) && blocks>(1U<<28))
+ blocks = (1U<<28);
+ /*
+ * As (*func) operates on 32-bit counter, caller
+ * has to handle overflow. 'if' below detects the
+ * overflow, which is then handled by limiting the
+ * amount of blocks to the exact overflow point...
+ */
+ ctr32 += (u32)blocks;
+ if (ctr32 < blocks) {
+ blocks -= ctr32;
+ ctr32 = 0;
+ }
+ (*func)(in,out,blocks,key,ivec);
+ /* (*ctr) does not update ivec, caller does: */
+ PUTU32(ivec+12,ctr32);
+ /* ... overflow was detected, propogate carry. */
+ if (ctr32 == 0) ctr96_inc(ivec);
+ blocks *= 16;
+ len -= blocks;
+ out += blocks;
+ in += blocks;
+ }
+ if (len) {
+ memset(ecount_buf,0,16);
+ (*func)(ecount_buf,ecount_buf,1,key,ivec);
+ ++ctr32;
+ PUTU32(ivec+12,ctr32);
+ if (ctr32 == 0) ctr96_inc(ivec);
+ while (len--) {
+ out[n] = in[n] ^ ecount_buf[n];
+ ++n;
+ }
+ }
+
+ *num=n;
+}