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[Qemu-devel] [PATCH v4 10/26] crypto: refactor code for dealing with AES
From: |
Daniel P. Berrange |
Subject: |
[Qemu-devel] [PATCH v4 10/26] crypto: refactor code for dealing with AES cipher |
Date: |
Mon, 29 Feb 2016 12:00:45 +0000 |
The built-in and nettle cipher backends for AES maintain
two separate AES contexts, one for encryption and one for
decryption. This is going to be inconvenient for the future
code dealing with XTS, so wrap them up in a single struct
so there is just one pointer to pass around for both
encryptin and decryption.
Signed-off-by: Daniel P. Berrange <address@hidden>
---
crypto/cipher-builtin.c | 126 ++++++++++++++++++++++++++++++------------------
crypto/cipher-nettle.c | 57 +++++++++++-----------
2 files changed, 109 insertions(+), 74 deletions(-)
diff --git a/crypto/cipher-builtin.c b/crypto/cipher-builtin.c
index 138b7a0..836ed1a 100644
--- a/crypto/cipher-builtin.c
+++ b/crypto/cipher-builtin.c
@@ -22,10 +22,14 @@
#include "crypto/aes.h"
#include "crypto/desrfb.h"
+typedef struct QCryptoCipherBuiltinAESContext QCryptoCipherBuiltinAESContext;
+struct QCryptoCipherBuiltinAESContext {
+ AES_KEY enc;
+ AES_KEY dec;
+};
typedef struct QCryptoCipherBuiltinAES QCryptoCipherBuiltinAES;
struct QCryptoCipherBuiltinAES {
- AES_KEY encrypt_key;
- AES_KEY decrypt_key;
+ QCryptoCipherBuiltinAESContext key;
uint8_t iv[AES_BLOCK_SIZE];
};
typedef struct QCryptoCipherBuiltinDESRFB QCryptoCipherBuiltinDESRFB;
@@ -67,6 +71,58 @@ static void qcrypto_cipher_free_aes(QCryptoCipher *cipher)
}
+static void qcrypto_cipher_aes_ecb_encrypt(AES_KEY *key,
+ const void *in,
+ void *out,
+ size_t len)
+{
+ const uint8_t *inptr = in;
+ uint8_t *outptr = out;
+ while (len) {
+ if (len > AES_BLOCK_SIZE) {
+ AES_encrypt(inptr, outptr, key);
+ inptr += AES_BLOCK_SIZE;
+ outptr += AES_BLOCK_SIZE;
+ len -= AES_BLOCK_SIZE;
+ } else {
+ uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
+ memcpy(tmp1, inptr, len);
+ /* Fill with 0 to avoid valgrind uninitialized reads */
+ memset(tmp1 + len, 0, sizeof(tmp1) - len);
+ AES_encrypt(tmp1, tmp2, key);
+ memcpy(outptr, tmp2, len);
+ len = 0;
+ }
+ }
+}
+
+
+static void qcrypto_cipher_aes_ecb_decrypt(AES_KEY *key,
+ const void *in,
+ void *out,
+ size_t len)
+{
+ const uint8_t *inptr = in;
+ uint8_t *outptr = out;
+ while (len) {
+ if (len > AES_BLOCK_SIZE) {
+ AES_decrypt(inptr, outptr, key);
+ inptr += AES_BLOCK_SIZE;
+ outptr += AES_BLOCK_SIZE;
+ len -= AES_BLOCK_SIZE;
+ } else {
+ uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
+ memcpy(tmp1, inptr, len);
+ /* Fill with 0 to avoid valgrind uninitialized reads */
+ memset(tmp1 + len, 0, sizeof(tmp1) - len);
+ AES_decrypt(tmp1, tmp2, key);
+ memcpy(outptr, tmp2, len);
+ len = 0;
+ }
+ }
+}
+
+
static int qcrypto_cipher_encrypt_aes(QCryptoCipher *cipher,
const void *in,
void *out,
@@ -75,29 +131,18 @@ static int qcrypto_cipher_encrypt_aes(QCryptoCipher
*cipher,
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
- if (cipher->mode == QCRYPTO_CIPHER_MODE_ECB) {
- const uint8_t *inptr = in;
- uint8_t *outptr = out;
- while (len) {
- if (len > AES_BLOCK_SIZE) {
- AES_encrypt(inptr, outptr, &ctxt->state.aes.encrypt_key);
- inptr += AES_BLOCK_SIZE;
- outptr += AES_BLOCK_SIZE;
- len -= AES_BLOCK_SIZE;
- } else {
- uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
- memcpy(tmp1, inptr, len);
- /* Fill with 0 to avoid valgrind uninitialized reads */
- memset(tmp1 + len, 0, sizeof(tmp1) - len);
- AES_encrypt(tmp1, tmp2, &ctxt->state.aes.encrypt_key);
- memcpy(outptr, tmp2, len);
- len = 0;
- }
- }
- } else {
+ switch (cipher->mode) {
+ case QCRYPTO_CIPHER_MODE_ECB:
+ qcrypto_cipher_aes_ecb_encrypt(&ctxt->state.aes.key.enc,
+ in, out, len);
+ break;
+ case QCRYPTO_CIPHER_MODE_CBC:
AES_cbc_encrypt(in, out, len,
- &ctxt->state.aes.encrypt_key,
+ &ctxt->state.aes.key.enc,
ctxt->state.aes.iv, 1);
+ break;
+ default:
+ g_assert_not_reached();
}
return 0;
@@ -112,29 +157,18 @@ static int qcrypto_cipher_decrypt_aes(QCryptoCipher
*cipher,
{
QCryptoCipherBuiltin *ctxt = cipher->opaque;
- if (cipher->mode == QCRYPTO_CIPHER_MODE_ECB) {
- const uint8_t *inptr = in;
- uint8_t *outptr = out;
- while (len) {
- if (len > AES_BLOCK_SIZE) {
- AES_decrypt(inptr, outptr, &ctxt->state.aes.decrypt_key);
- inptr += AES_BLOCK_SIZE;
- outptr += AES_BLOCK_SIZE;
- len -= AES_BLOCK_SIZE;
- } else {
- uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
- memcpy(tmp1, inptr, len);
- /* Fill with 0 to avoid valgrind uninitialized reads */
- memset(tmp1 + len, 0, sizeof(tmp1) - len);
- AES_decrypt(tmp1, tmp2, &ctxt->state.aes.decrypt_key);
- memcpy(outptr, tmp2, len);
- len = 0;
- }
- }
- } else {
+ switch (cipher->mode) {
+ case QCRYPTO_CIPHER_MODE_ECB:
+ qcrypto_cipher_aes_ecb_decrypt(&ctxt->state.aes.key.dec,
+ in, out, len);
+ break;
+ case QCRYPTO_CIPHER_MODE_CBC:
AES_cbc_encrypt(in, out, len,
- &ctxt->state.aes.decrypt_key,
+ &ctxt->state.aes.key.dec,
ctxt->state.aes.iv, 0);
+ break;
+ default:
+ g_assert_not_reached();
}
return 0;
@@ -173,12 +207,12 @@ static int qcrypto_cipher_init_aes(QCryptoCipher *cipher,
ctxt = g_new0(QCryptoCipherBuiltin, 1);
- if (AES_set_encrypt_key(key, nkey * 8, &ctxt->state.aes.encrypt_key) != 0)
{
+ if (AES_set_encrypt_key(key, nkey * 8, &ctxt->state.aes.key.enc) != 0) {
error_setg(errp, "Failed to set encryption key");
goto error;
}
- if (AES_set_decrypt_key(key, nkey * 8, &ctxt->state.aes.decrypt_key) != 0)
{
+ if (AES_set_decrypt_key(key, nkey * 8, &ctxt->state.aes.key.dec) != 0) {
error_setg(errp, "Failed to set decryption key");
goto error;
}
diff --git a/crypto/cipher-nettle.c b/crypto/cipher-nettle.c
index 9b057fd..ed08782 100644
--- a/crypto/cipher-nettle.c
+++ b/crypto/cipher-nettle.c
@@ -42,16 +42,23 @@ static nettle_cipher_func aes_decrypt_wrapper;
static nettle_cipher_func des_encrypt_wrapper;
static nettle_cipher_func des_decrypt_wrapper;
+typedef struct QCryptoNettleAES {
+ struct aes_ctx enc;
+ struct aes_ctx dec;
+} QCryptoNettleAES;
+
static void aes_encrypt_wrapper(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
- aes_encrypt(ctx, length, dst, src);
+ const QCryptoNettleAES *aesctx = ctx;
+ aes_encrypt(&aesctx->enc, length, dst, src);
}
static void aes_decrypt_wrapper(cipher_ctx_t ctx, cipher_length_t length,
uint8_t *dst, const uint8_t *src)
{
- aes_decrypt(ctx, length, dst, src);
+ const QCryptoNettleAES *aesctx = ctx;
+ aes_decrypt(&aesctx->dec, length, dst, src);
}
static void des_encrypt_wrapper(cipher_ctx_t ctx, cipher_length_t length,
@@ -104,8 +111,7 @@ static void twofish_decrypt_wrapper(cipher_ctx_t ctx,
cipher_length_t length,
typedef struct QCryptoCipherNettle QCryptoCipherNettle;
struct QCryptoCipherNettle {
- void *ctx_encrypt;
- void *ctx_decrypt;
+ void *ctx;
nettle_cipher_func *alg_encrypt;
nettle_cipher_func *alg_decrypt;
uint8_t *iv;
@@ -163,10 +169,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm
alg,
switch (alg) {
case QCRYPTO_CIPHER_ALG_DES_RFB:
- ctx->ctx_encrypt = g_new0(struct des_ctx, 1);
- ctx->ctx_decrypt = NULL; /* 1 ctx can do both */
+ ctx->ctx = g_new0(struct des_ctx, 1);
rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
- des_set_key(ctx->ctx_encrypt, rfbkey);
+ des_set_key(ctx->ctx, rfbkey);
g_free(rfbkey);
ctx->alg_encrypt = des_encrypt_wrapper;
@@ -178,11 +183,10 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm
alg,
case QCRYPTO_CIPHER_ALG_AES_128:
case QCRYPTO_CIPHER_ALG_AES_192:
case QCRYPTO_CIPHER_ALG_AES_256:
- ctx->ctx_encrypt = g_new0(struct aes_ctx, 1);
- ctx->ctx_decrypt = g_new0(struct aes_ctx, 1);
+ ctx->ctx = g_new0(QCryptoNettleAES, 1);
- aes_set_encrypt_key(ctx->ctx_encrypt, nkey, key);
- aes_set_decrypt_key(ctx->ctx_decrypt, nkey, key);
+ aes_set_encrypt_key(&((QCryptoNettleAES *)ctx->ctx)->enc, nkey, key);
+ aes_set_decrypt_key(&((QCryptoNettleAES *)ctx->ctx)->dec, nkey, key);
ctx->alg_encrypt = aes_encrypt_wrapper;
ctx->alg_decrypt = aes_decrypt_wrapper;
@@ -191,10 +195,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm
alg,
break;
case QCRYPTO_CIPHER_ALG_CAST5_128:
- ctx->ctx_encrypt = g_new0(struct cast128_ctx, 1);
- ctx->ctx_decrypt = NULL; /* 1 ctx can do both */
+ ctx->ctx = g_new0(struct cast128_ctx, 1);
- cast5_set_key(ctx->ctx_encrypt, nkey, key);
+ cast5_set_key(ctx->ctx, nkey, key);
ctx->alg_encrypt = cast128_encrypt_wrapper;
ctx->alg_decrypt = cast128_decrypt_wrapper;
@@ -205,10 +208,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm
alg,
case QCRYPTO_CIPHER_ALG_SERPENT_128:
case QCRYPTO_CIPHER_ALG_SERPENT_192:
case QCRYPTO_CIPHER_ALG_SERPENT_256:
- ctx->ctx_encrypt = g_new0(struct serpent_ctx, 1);
- ctx->ctx_decrypt = NULL; /* 1 ctx can do both */
+ ctx->ctx = g_new0(struct serpent_ctx, 1);
- serpent_set_key(ctx->ctx_encrypt, nkey, key);
+ serpent_set_key(ctx->ctx, nkey, key);
ctx->alg_encrypt = serpent_encrypt_wrapper;
ctx->alg_decrypt = serpent_decrypt_wrapper;
@@ -219,10 +221,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm
alg,
case QCRYPTO_CIPHER_ALG_TWOFISH_128:
case QCRYPTO_CIPHER_ALG_TWOFISH_192:
case QCRYPTO_CIPHER_ALG_TWOFISH_256:
- ctx->ctx_encrypt = g_new0(struct twofish_ctx, 1);
- ctx->ctx_decrypt = NULL; /* 1 ctx can do both */
+ ctx->ctx = g_new0(struct twofish_ctx, 1);
- twofish_set_key(ctx->ctx_encrypt, nkey, key);
+ twofish_set_key(ctx->ctx, nkey, key);
ctx->alg_encrypt = twofish_encrypt_wrapper;
ctx->alg_decrypt = twofish_decrypt_wrapper;
@@ -257,8 +258,7 @@ void qcrypto_cipher_free(QCryptoCipher *cipher)
ctx = cipher->opaque;
g_free(ctx->iv);
- g_free(ctx->ctx_encrypt);
- g_free(ctx->ctx_decrypt);
+ g_free(ctx->ctx);
g_free(ctx);
g_free(cipher);
}
@@ -280,14 +280,15 @@ int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
switch (cipher->mode) {
case QCRYPTO_CIPHER_MODE_ECB:
- ctx->alg_encrypt(ctx->ctx_encrypt, len, out, in);
+ ctx->alg_encrypt(ctx->ctx, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CBC:
- cbc_encrypt(ctx->ctx_encrypt, ctx->alg_encrypt,
+ cbc_encrypt(ctx->ctx, ctx->alg_encrypt,
ctx->blocksize, ctx->iv,
len, out, in);
break;
+
default:
error_setg(errp, "Unsupported cipher algorithm %d",
cipher->alg);
@@ -313,15 +314,15 @@ int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
switch (cipher->mode) {
case QCRYPTO_CIPHER_MODE_ECB:
- ctx->alg_decrypt(ctx->ctx_decrypt ? ctx->ctx_decrypt :
ctx->ctx_encrypt,
- len, out, in);
+ ctx->alg_decrypt(ctx->ctx, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CBC:
- cbc_decrypt(ctx->ctx_decrypt ? ctx->ctx_decrypt : ctx->ctx_encrypt,
- ctx->alg_decrypt, ctx->blocksize, ctx->iv,
+ cbc_decrypt(ctx->ctx, ctx->alg_decrypt,
+ ctx->blocksize, ctx->iv,
len, out, in);
break;
+
default:
error_setg(errp, "Unsupported cipher algorithm %d",
cipher->alg);
--
2.5.0
- [Qemu-devel] [PATCH v4 08/26] crypto: add support for the twofish cipher algorithm, (continued)
- [Qemu-devel] [PATCH v4 08/26] crypto: add support for the twofish cipher algorithm, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 15/26] qemu-img/qemu-io: don't prompt for passwords if not required, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 16/26] tests: redirect stderr to stdout for iotests, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 12/26] crypto: add block encryption framework, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 18/26] tests: add output filter to python I/O tests helper, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 09/26] crypto: import an implementation of the XTS cipher mode, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 14/26] block: add flag to indicate that no I/O will be performed, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 23/26] qcow: convert QCow to use QCryptoBlock for encryption, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 11/26] crypto: wire up XTS mode for cipher APIs, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 17/26] tests: refactor python I/O tests helper main method, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 10/26] crypto: refactor code for dealing with AES cipher,
Daniel P. Berrange <=
- [Qemu-devel] [PATCH v4 20/26] qcow2: make qcow2_encrypt_sectors encrypt in place, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 22/26] qcow: make encrypt_sectors encrypt in place, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 24/26] block: rip out all traces of password prompting, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 26/26] block: remove support for legecy AES qcow/qcow2 encryption, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 13/26] crypto: implement the LUKS block encryption format, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 25/26] block: remove all encryption handling APIs, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 21/26] qcow2: convert QCow2 to use QCryptoBlock for encryption, Daniel P. Berrange, 2016/02/29
- [Qemu-devel] [PATCH v4 19/26] block: add generic full disk encryption driver, Daniel P. Berrange, 2016/02/29