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-rw-r--r--crypto/modes/xts128.c243
1 files changed, 130 insertions, 113 deletions
diff --git a/crypto/modes/xts128.c b/crypto/modes/xts128.c
index 9cf27a25e960..8f2af588b26d 100644
--- a/crypto/modes/xts128.c
+++ b/crypto/modes/xts128.c
@@ -6,7 +6,7 @@
* are met:
*
* 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
+ * notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
@@ -58,130 +58,147 @@
#endif
#include <assert.h>
-int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char iv[16],
- const unsigned char *inp, unsigned char *out,
- size_t len, int enc)
+int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
+ const unsigned char iv[16],
+ const unsigned char *inp, unsigned char *out,
+ size_t len, int enc)
{
- const union { long one; char little; } is_endian = {1};
- union { u64 u[2]; u32 d[4]; u8 c[16]; } tweak, scratch;
- unsigned int i;
-
- if (len<16) return -1;
-
- memcpy(tweak.c, iv, 16);
-
- (*ctx->block2)(tweak.c,tweak.c,ctx->key2);
-
- if (!enc && (len%16)) len-=16;
-
- while (len>=16) {
+ const union {
+ long one;
+ char little;
+ } is_endian = {
+ 1
+ };
+ union {
+ u64 u[2];
+ u32 d[4];
+ u8 c[16];
+ } tweak, scratch;
+ unsigned int i;
+
+ if (len < 16)
+ return -1;
+
+ memcpy(tweak.c, iv, 16);
+
+ (*ctx->block2) (tweak.c, tweak.c, ctx->key2);
+
+ if (!enc && (len % 16))
+ len -= 16;
+
+ while (len >= 16) {
#if defined(STRICT_ALIGNMENT)
- memcpy(scratch.c,inp,16);
- scratch.u[0] ^= tweak.u[0];
- scratch.u[1] ^= tweak.u[1];
+ memcpy(scratch.c, inp, 16);
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
#else
- scratch.u[0] = ((u64*)inp)[0]^tweak.u[0];
- scratch.u[1] = ((u64*)inp)[1]^tweak.u[1];
+ scratch.u[0] = ((u64 *)inp)[0] ^ tweak.u[0];
+ scratch.u[1] = ((u64 *)inp)[1] ^ tweak.u[1];
#endif
- (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
+ (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
#if defined(STRICT_ALIGNMENT)
- scratch.u[0] ^= tweak.u[0];
- scratch.u[1] ^= tweak.u[1];
- memcpy(out,scratch.c,16);
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ memcpy(out, scratch.c, 16);
#else
- ((u64*)out)[0] = scratch.u[0]^=tweak.u[0];
- ((u64*)out)[1] = scratch.u[1]^=tweak.u[1];
+ ((u64 *)out)[0] = scratch.u[0] ^= tweak.u[0];
+ ((u64 *)out)[1] = scratch.u[1] ^= tweak.u[1];
#endif
- inp += 16;
- out += 16;
- len -= 16;
-
- if (len==0) return 0;
-
- if (is_endian.little) {
- unsigned int carry,res;
-
- res = 0x87&(((int)tweak.d[3])>>31);
- carry = (unsigned int)(tweak.u[0]>>63);
- tweak.u[0] = (tweak.u[0]<<1)^res;
- tweak.u[1] = (tweak.u[1]<<1)|carry;
- }
- else {
- size_t c;
-
- for (c=0,i=0;i<16;++i) {
- /*+ substitutes for |, because c is 1 bit */
- c += ((size_t)tweak.c[i])<<1;
- tweak.c[i] = (u8)c;
- c = c>>8;
- }
- tweak.c[0] ^= (u8)(0x87&(0-c));
- }
- }
- if (enc) {
- for (i=0;i<len;++i) {
- u8 c = inp[i];
- out[i] = scratch.c[i];
- scratch.c[i] = c;
- }
- scratch.u[0] ^= tweak.u[0];
- scratch.u[1] ^= tweak.u[1];
- (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
- scratch.u[0] ^= tweak.u[0];
- scratch.u[1] ^= tweak.u[1];
- memcpy(out-16,scratch.c,16);
- }
- else {
- union { u64 u[2]; u8 c[16]; } tweak1;
-
- if (is_endian.little) {
- unsigned int carry,res;
-
- res = 0x87&(((int)tweak.d[3])>>31);
- carry = (unsigned int)(tweak.u[0]>>63);
- tweak1.u[0] = (tweak.u[0]<<1)^res;
- tweak1.u[1] = (tweak.u[1]<<1)|carry;
- }
- else {
- size_t c;
-
- for (c=0,i=0;i<16;++i) {
- /*+ substitutes for |, because c is 1 bit */
- c += ((size_t)tweak.c[i])<<1;
- tweak1.c[i] = (u8)c;
- c = c>>8;
- }
- tweak1.c[0] ^= (u8)(0x87&(0-c));
- }
+ inp += 16;
+ out += 16;
+ len -= 16;
+
+ if (len == 0)
+ return 0;
+
+ if (is_endian.little) {
+ unsigned int carry, res;
+
+ res = 0x87 & (((int)tweak.d[3]) >> 31);
+ carry = (unsigned int)(tweak.u[0] >> 63);
+ tweak.u[0] = (tweak.u[0] << 1) ^ res;
+ tweak.u[1] = (tweak.u[1] << 1) | carry;
+ } else {
+ size_t c;
+
+ for (c = 0, i = 0; i < 16; ++i) {
+ /*
+ * + substitutes for |, because c is 1 bit
+ */
+ c += ((size_t)tweak.c[i]) << 1;
+ tweak.c[i] = (u8)c;
+ c = c >> 8;
+ }
+ tweak.c[0] ^= (u8)(0x87 & (0 - c));
+ }
+ }
+ if (enc) {
+ for (i = 0; i < len; ++i) {
+ u8 c = inp[i];
+ out[i] = scratch.c[i];
+ scratch.c[i] = c;
+ }
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ memcpy(out - 16, scratch.c, 16);
+ } else {
+ union {
+ u64 u[2];
+ u8 c[16];
+ } tweak1;
+
+ if (is_endian.little) {
+ unsigned int carry, res;
+
+ res = 0x87 & (((int)tweak.d[3]) >> 31);
+ carry = (unsigned int)(tweak.u[0] >> 63);
+ tweak1.u[0] = (tweak.u[0] << 1) ^ res;
+ tweak1.u[1] = (tweak.u[1] << 1) | carry;
+ } else {
+ size_t c;
+
+ for (c = 0, i = 0; i < 16; ++i) {
+ /*
+ * + substitutes for |, because c is 1 bit
+ */
+ c += ((size_t)tweak.c[i]) << 1;
+ tweak1.c[i] = (u8)c;
+ c = c >> 8;
+ }
+ tweak1.c[0] ^= (u8)(0x87 & (0 - c));
+ }
#if defined(STRICT_ALIGNMENT)
- memcpy(scratch.c,inp,16);
- scratch.u[0] ^= tweak1.u[0];
- scratch.u[1] ^= tweak1.u[1];
+ memcpy(scratch.c, inp, 16);
+ scratch.u[0] ^= tweak1.u[0];
+ scratch.u[1] ^= tweak1.u[1];
#else
- scratch.u[0] = ((u64*)inp)[0]^tweak1.u[0];
- scratch.u[1] = ((u64*)inp)[1]^tweak1.u[1];
+ scratch.u[0] = ((u64 *)inp)[0] ^ tweak1.u[0];
+ scratch.u[1] = ((u64 *)inp)[1] ^ tweak1.u[1];
#endif
- (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
- scratch.u[0] ^= tweak1.u[0];
- scratch.u[1] ^= tweak1.u[1];
-
- for (i=0;i<len;++i) {
- u8 c = inp[16+i];
- out[16+i] = scratch.c[i];
- scratch.c[i] = c;
- }
- scratch.u[0] ^= tweak.u[0];
- scratch.u[1] ^= tweak.u[1];
- (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
+ (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
+ scratch.u[0] ^= tweak1.u[0];
+ scratch.u[1] ^= tweak1.u[1];
+
+ for (i = 0; i < len; ++i) {
+ u8 c = inp[16 + i];
+ out[16 + i] = scratch.c[i];
+ scratch.c[i] = c;
+ }
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
#if defined(STRICT_ALIGNMENT)
- scratch.u[0] ^= tweak.u[0];
- scratch.u[1] ^= tweak.u[1];
- memcpy (out,scratch.c,16);
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ memcpy(out, scratch.c, 16);
#else
- ((u64*)out)[0] = scratch.u[0]^tweak.u[0];
- ((u64*)out)[1] = scratch.u[1]^tweak.u[1];
+ ((u64 *)out)[0] = scratch.u[0] ^ tweak.u[0];
+ ((u64 *)out)[1] = scratch.u[1] ^ tweak.u[1];
#endif
- }
+ }
- return 0;
+ return 0;
}