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crypto: add CTR mode support

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Introduce CTR mode support for the cipher APIs.
CTR mode uses a counter rather than a traditional IV.
The counter has additional properties, including a nonce
and initial counter block. We reuse the ctx->iv as
the counter for conveniences.

Both libgcrypt and nettle are support CTR mode, the
cipher-builtin doesn't support yet.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Gonglei 2016-09-26 17:23:22 +08:00 committed by Daniel P. Berrange
parent f844836ddc
commit 3c28292f39
6 changed files with 94 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
crypto/cipher-gcrypt.c
View File

@ -59,6 +59,7 @@ struct QCryptoCipherGcrypt {
gcry_cipher_hd_t handle;
gcry_cipher_hd_t tweakhandle;
size_t blocksize;
/* Initialization vector or Counter */
uint8_t *iv;
};
@ -80,6 +81,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
case QCRYPTO_CIPHER_MODE_CBC:
gcrymode = GCRY_CIPHER_MODE_CBC;
break;
case QCRYPTO_CIPHER_MODE_CTR:
gcrymode = GCRY_CIPHER_MODE_CTR;
break;
default:
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_lookup[mode]);
@ -350,12 +354,21 @@ int qcrypto_cipher_setiv(QCryptoCipher *cipher,
if (ctx->iv) {
memcpy(ctx->iv, iv, niv);
} else {
gcry_cipher_reset(ctx->handle);
err = gcry_cipher_setiv(ctx->handle, iv, niv);
if (err != 0) {
error_setg(errp, "Cannot set IV: %s",
gcry_strerror(err));
return -1;
if (cipher->mode == QCRYPTO_CIPHER_MODE_CTR) {
err = gcry_cipher_setctr(ctx->handle, iv, niv);
if (err != 0) {
error_setg(errp, "Cannot set Counter: %s",
gcry_strerror(err));
return -1;
}
} else {
gcry_cipher_reset(ctx->handle);
err = gcry_cipher_setiv(ctx->handle, iv, niv);
if (err != 0) {
error_setg(errp, "Cannot set IV: %s",
gcry_strerror(err));
return -1;
}
}
}

15
crypto/cipher-nettle.c
View File

@ -28,6 +28,7 @@
#include <nettle/cast128.h>
#include <nettle/serpent.h>
#include <nettle/twofish.h>
#include <nettle/ctr.h>
typedef void (*QCryptoCipherNettleFuncWrapper)(const void *ctx,
size_t length,
@ -186,7 +187,7 @@ struct QCryptoCipherNettle {
QCryptoCipherNettleFuncNative alg_decrypt_native;
QCryptoCipherNettleFuncWrapper alg_encrypt_wrapper;
QCryptoCipherNettleFuncWrapper alg_decrypt_wrapper;
/* Initialization vector or Counter */
uint8_t *iv;
size_t blocksize;
};
@ -236,6 +237,7 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
case QCRYPTO_CIPHER_MODE_ECB:
case QCRYPTO_CIPHER_MODE_CBC:
case QCRYPTO_CIPHER_MODE_XTS:
case QCRYPTO_CIPHER_MODE_CTR:
break;
default:
error_setg(errp, "Unsupported cipher mode %s",
@ -441,6 +443,12 @@ int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
ctx->iv, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CTR:
ctr_crypt(ctx->ctx, ctx->alg_encrypt_native,
ctx->blocksize, ctx->iv,
len, out, in);
break;
default:
error_setg(errp, "Unsupported cipher mode %s",
QCryptoCipherMode_lookup[cipher->mode]);
@ -480,6 +488,11 @@ int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
ctx->alg_encrypt_wrapper, ctx->alg_decrypt_wrapper,
ctx->iv, len, out, in);
break;
case QCRYPTO_CIPHER_MODE_CTR:
ctr_crypt(ctx->ctx, ctx->alg_encrypt_native,
ctx->blocksize, ctx->iv,
len, out, in);
break;
default:
error_setg(errp, "Unsupported cipher mode %s",

1
crypto/cipher.c
View File

@ -55,6 +55,7 @@ static bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
[QCRYPTO_CIPHER_MODE_ECB] = false,
[QCRYPTO_CIPHER_MODE_CBC] = true,
[QCRYPTO_CIPHER_MODE_XTS] = true,
[QCRYPTO_CIPHER_MODE_CTR] = true,
};

6
include/crypto/cipher.h
View File

@ -215,16 +215,16 @@ int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
/**
* qcrypto_cipher_setiv:
* @cipher: the cipher object
* @iv: the initialization vector bytes
* @iv: the initialization vector or counter (CTR mode) bytes
* @niv: the length of @iv
* @errpr: pointer to a NULL-initialized error object
*
* If the @cipher object is setup to use a mode that requires
* initialization vectors, this sets the initialization vector
* initialization vectors or counter, this sets the @niv
* bytes. The @iv data should have the same length as the
* cipher key used when originally constructing the cipher
* object. It is an error to set an initialization vector
* if the cipher mode does not require one.
* or counter if the cipher mode does not require one.
*
* Returns: 0 on success, -1 on error
*/

3
qapi/crypto.json
View File

@ -89,11 +89,12 @@
# @ecb: Electronic Code Book
# @cbc: Cipher Block Chaining
# @xts: XEX with tweaked code book and ciphertext stealing
# @ctr: Counter (Since 2.8)
# Since: 2.6
##
{ 'enum': 'QCryptoCipherMode',
'prefix': 'QCRYPTO_CIPHER_MODE',
'data': ['ecb', 'cbc', 'xts']}
'data': ['ecb', 'cbc', 'xts', 'ctr']}
##

55
tests/test-crypto-cipher.c
View File

@ -380,6 +380,61 @@ static QCryptoCipherTestData test_data[] = {
.key =
"27182818284590452353602874713526"
"31415926535897932384626433832795",
},
{
/* NIST F.5.1 CTR-AES128.Encrypt */
.path = "/crypto/cipher/aes-ctr-128",
.alg = QCRYPTO_CIPHER_ALG_AES_128,
.mode = QCRYPTO_CIPHER_MODE_CTR,
.key = "2b7e151628aed2a6abf7158809cf4f3c",
.iv = "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff",
.plaintext =
"6bc1bee22e409f96e93d7e117393172a"
"ae2d8a571e03ac9c9eb76fac45af8e51"
"30c81c46a35ce411e5fbc1191a0a52ef"
"f69f2445df4f9b17ad2b417be66c3710",
.ciphertext =
"874d6191b620e3261bef6864990db6ce"
"9806f66b7970fdff8617187bb9fffdff"
"5ae4df3edbd5d35e5b4f09020db03eab"
"1e031dda2fbe03d1792170a0f3009cee",
},
{
/* NIST F.5.3 CTR-AES192.Encrypt */
.path = "/crypto/cipher/aes-ctr-192",
.alg = QCRYPTO_CIPHER_ALG_AES_192,
.mode = QCRYPTO_CIPHER_MODE_CTR,
.key = "8e73b0f7da0e6452c810f32b809079e562f8ead2522c6b7b",
.iv = "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff",
.plaintext =
"6bc1bee22e409f96e93d7e117393172a"
"ae2d8a571e03ac9c9eb76fac45af8e51"
"30c81c46a35ce411e5fbc1191a0a52ef"
"f69f2445df4f9b17ad2b417be66c3710",
.ciphertext =
"1abc932417521ca24f2b0459fe7e6e0b"
"090339ec0aa6faefd5ccc2c6f4ce8e94"
"1e36b26bd1ebc670d1bd1d665620abf7"
"4f78a7f6d29809585a97daec58c6b050",
},
{
/* NIST F.5.5 CTR-AES256.Encrypt */
.path = "/crypto/cipher/aes-ctr-256",
.alg = QCRYPTO_CIPHER_ALG_AES_256,
.mode = QCRYPTO_CIPHER_MODE_CTR,
.key = "603deb1015ca71be2b73aef0857d7781"
"1f352c073b6108d72d9810a30914dff4",
.iv = "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff",
.plaintext =
"6bc1bee22e409f96e93d7e117393172a"
"ae2d8a571e03ac9c9eb76fac45af8e51"
"30c81c46a35ce411e5fbc1191a0a52ef"
"f69f2445df4f9b17ad2b417be66c3710",
.ciphertext =
"601ec313775789a5b7a7f504bbf3d228"
"f443e3ca4d62b59aca84e990cacaf5c5"
"2b0930daa23de94ce87017ba2d84988d"
"dfc9c58db67aada613c2dd08457941a6",
}
};