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Differential D33529 Diff 100186 sys/opencrypto/xform_aes_xts.c

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sys/opencrypto/xform_aes_xts.c

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__FBSDID("$FreeBSD$"); __FBSDID("$FreeBSD$");
#include <sys/types.h> #include <sys/types.h>
#include <opencrypto/xform_enc.h> #include <opencrypto/xform_enc.h>
static int aes_xts_setkey(void *, const uint8_t *, int); static int aes_xts_setkey(void *, const uint8_t *, int);
static void aes_xts_encrypt(void *, const uint8_t *, uint8_t *); static void aes_xts_encrypt(void *, const uint8_t *, uint8_t *);
static void aes_xts_decrypt(void *, const uint8_t *, uint8_t *); static void aes_xts_decrypt(void *, const uint8_t *, uint8_t *);
static void aes_xts_encrypt_multi(void *, const uint8_t *, uint8_t *, size_t);
static void aes_xts_decrypt_multi(void *, const uint8_t *, uint8_t *, size_t);
static void aes_xts_reinit(void *, const uint8_t *, size_t); static void aes_xts_reinit(void *, const uint8_t *, size_t);
/* Encryption instances */ /* Encryption instances */
const struct enc_xform enc_xform_aes_xts = { const struct enc_xform enc_xform_aes_xts = {
.type = CRYPTO_AES_XTS, .type = CRYPTO_AES_XTS,
.name = "AES-XTS", .name = "AES-XTS",
.ctxsize = sizeof(struct aes_xts_ctx), .ctxsize = sizeof(struct aes_xts_ctx),
.blocksize = AES_BLOCK_LEN, .blocksize = AES_BLOCK_LEN,
.ivsize = AES_XTS_IV_LEN, .ivsize = AES_XTS_IV_LEN,
.minkey = AES_XTS_MIN_KEY, .minkey = AES_XTS_MIN_KEY,
.maxkey = AES_XTS_MAX_KEY, .maxkey = AES_XTS_MAX_KEY,
.setkey = aes_xts_setkey,
.reinit = aes_xts_reinit,
.encrypt = aes_xts_encrypt, .encrypt = aes_xts_encrypt,
.decrypt = aes_xts_decrypt, .decrypt = aes_xts_decrypt,
.setkey = aes_xts_setkey, .encrypt_multi = aes_xts_encrypt_multi,
.reinit = aes_xts_reinit .decrypt_multi = aes_xts_decrypt_multi,
}; };
/* /*
* Encryption wrapper routines. * Encryption wrapper routines.
*/ */
static void static void
aes_xts_reinit(void *key, const uint8_t *iv, size_t ivlen) aes_xts_reinit(void *key, const uint8_t *iv, size_t ivlen)
{ {
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/* Last 64 bits of IV are always zero */ /* Last 64 bits of IV are always zero */
bzero(ctx->tweak + AES_XTS_IVSIZE, AES_XTS_IVSIZE); bzero(ctx->tweak + AES_XTS_IVSIZE, AES_XTS_IVSIZE);
rijndael_encrypt(&ctx->key2, ctx->tweak, ctx->tweak); rijndael_encrypt(&ctx->key2, ctx->tweak, ctx->tweak);
} }
static void static void
aes_xts_crypt(struct aes_xts_ctx *ctx, const uint8_t *in, uint8_t *out, aes_xts_crypt(struct aes_xts_ctx *ctx, const uint8_t *in, uint8_t *out,
u_int do_encrypt) size_t len, bool do_encrypt)
{ {
uint8_t block[AES_XTS_BLOCKSIZE]; uint8_t block[AES_XTS_BLOCKSIZE];
u_int i, carry_in, carry_out; u_int i, carry_in, carry_out;
while (len > 0) {
for (i = 0; i < AES_XTS_BLOCKSIZE; i++) for (i = 0; i < AES_XTS_BLOCKSIZE; i++)
block[i] = in[i] ^ ctx->tweak[i]; block[i] = in[i] ^ ctx->tweak[i];
if (do_encrypt) if (do_encrypt)
rijndael_encrypt(&ctx->key1, block, out); rijndael_encrypt(&ctx->key1, block, out);
else else
rijndael_decrypt(&ctx->key1, block, out); rijndael_decrypt(&ctx->key1, block, out);
for (i = 0; i < AES_XTS_BLOCKSIZE; i++) for (i = 0; i < AES_XTS_BLOCKSIZE; i++)
out[i] ^= ctx->tweak[i]; out[i] ^= ctx->tweak[i];
/* Exponentiate tweak */ /* Exponentiate tweak */
carry_in = 0; carry_in = 0;
for (i = 0; i < AES_XTS_BLOCKSIZE; i++) { for (i = 0; i < AES_XTS_BLOCKSIZE; i++) {
carry_out = ctx->tweak[i] & 0x80; carry_out = ctx->tweak[i] & 0x80;
ctx->tweak[i] = (ctx->tweak[i] << 1) | (carry_in ? 1 : 0); ctx->tweak[i] = (ctx->tweak[i] << 1) | (carry_in ? 1 : 0);
carry_in = carry_out; carry_in = carry_out;
} }
if (carry_in) if (carry_in)
ctx->tweak[0] ^= AES_XTS_ALPHA; ctx->tweak[0] ^= AES_XTS_ALPHA;
in += AES_XTS_BLOCKSIZE;
out += AES_XTS_BLOCKSIZE;
len -= AES_XTS_BLOCKSIZE;
}
explicit_bzero(block, sizeof(block)); explicit_bzero(block, sizeof(block));
} }
static void static void
aes_xts_encrypt(void *key, const uint8_t *in, uint8_t *out) aes_xts_encrypt(void *key, const uint8_t *in, uint8_t *out)
{ {
aes_xts_crypt(key, in, out, 1); aes_xts_crypt(key, in, out, AES_XTS_BLOCKSIZE, true);
} }
static void static void
aes_xts_decrypt(void *key, const uint8_t *in, uint8_t *out) aes_xts_decrypt(void *key, const uint8_t *in, uint8_t *out)
{ {
aes_xts_crypt(key, in, out, 0); aes_xts_crypt(key, in, out, AES_XTS_BLOCKSIZE, false);
}
static void
aes_xts_encrypt_multi(void *vctx, const uint8_t *in, uint8_t *out, size_t len)
{
aes_xts_crypt(vctx, in, out, len, true);
}
static void
aes_xts_decrypt_multi(void *vctx, const uint8_t *in, uint8_t *out, size_t len)
{
aes_xts_crypt(vctx, in, out, len, false);
} }
static int static int
aes_xts_setkey(void *sched, const uint8_t *key, int len) aes_xts_setkey(void *sched, const uint8_t *key, int len)
{ {
struct aes_xts_ctx *ctx; struct aes_xts_ctx *ctx;
if (len != 32 && len != 64) if (len != 32 && len != 64)
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