Re: [PATCH v6] crypto: Introduce SM4 symmetric cipher algorithm

[Thomas Huth <thuth@redhat.com>]

On 07/12/2023 16.47, Hyman Huang wrote:
> Introduce the SM4 cipher algorithms (OSCCA GB/T 32907-2016).
> 
> SM4 (GBT.32907-2016) is a cryptographic standard issued by the
> Organization of State Commercial Administration of China (OSCCA)
> as an authorized cryptographic algorithms for the use within China.
> 
> Detect the SM4 cipher algorithms and enable the feature silently
> if it is available.
> 
> Signed-off-by: Hyman Huang <yong.huang@smartx.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---

FYI, starting with this commit, tests/unit/test-crypto-cipher is now failing 
on s390x hosts (i.e. big endian machines)... could be that there is maybe an 
endianess issue somewhere in here...

  Thomas



> diff --git a/crypto/block-luks.c b/crypto/block-luks.c
> index fb01ec38bb..f0813d69b4 100644
> --- a/crypto/block-luks.c
> +++ b/crypto/block-luks.c
> @@ -95,12 +95,23 @@ qcrypto_block_luks_cipher_size_map_twofish[] = {
>       { 0, 0 },
>   };
>   
> +#ifdef CONFIG_CRYPTO_SM4
> +static const QCryptoBlockLUKSCipherSizeMap
> +qcrypto_block_luks_cipher_size_map_sm4[] = {
> +    { 16, QCRYPTO_CIPHER_ALG_SM4},
> +    { 0, 0 },
> +};
> +#endif
> +
>   static const QCryptoBlockLUKSCipherNameMap
>   qcrypto_block_luks_cipher_name_map[] = {
>       { "aes", qcrypto_block_luks_cipher_size_map_aes },
>       { "cast5", qcrypto_block_luks_cipher_size_map_cast5 },
>       { "serpent", qcrypto_block_luks_cipher_size_map_serpent },
>       { "twofish", qcrypto_block_luks_cipher_size_map_twofish },
> +#ifdef CONFIG_CRYPTO_SM4
> +    { "sm4", qcrypto_block_luks_cipher_size_map_sm4},
> +#endif
>   };
>   
>   QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
> diff --git a/crypto/cipher-gcrypt.c.inc b/crypto/cipher-gcrypt.c.inc
> index a6a0117717..1377cbaf14 100644
> --- a/crypto/cipher-gcrypt.c.inc
> +++ b/crypto/cipher-gcrypt.c.inc
> @@ -35,6 +35,9 @@ bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
>       case QCRYPTO_CIPHER_ALG_SERPENT_256:
>       case QCRYPTO_CIPHER_ALG_TWOFISH_128:
>       case QCRYPTO_CIPHER_ALG_TWOFISH_256:
> +#ifdef CONFIG_CRYPTO_SM4
> +    case QCRYPTO_CIPHER_ALG_SM4:
> +#endif
>           break;
>       default:
>           return false;
> @@ -219,6 +222,11 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
>       case QCRYPTO_CIPHER_ALG_TWOFISH_256:
>           gcryalg = GCRY_CIPHER_TWOFISH;
>           break;
> +#ifdef CONFIG_CRYPTO_SM4
> +    case QCRYPTO_CIPHER_ALG_SM4:
> +        gcryalg = GCRY_CIPHER_SM4;
> +        break;
> +#endif
>       default:
>           error_setg(errp, "Unsupported cipher algorithm %s",
>                      QCryptoCipherAlgorithm_str(alg));
> diff --git a/crypto/cipher-nettle.c.inc b/crypto/cipher-nettle.c.inc
> index 24cc61f87b..42b39e18a2 100644
> --- a/crypto/cipher-nettle.c.inc
> +++ b/crypto/cipher-nettle.c.inc
> @@ -33,6 +33,9 @@
>   #ifndef CONFIG_QEMU_PRIVATE_XTS
>   #include <nettle/xts.h>
>   #endif
> +#ifdef CONFIG_CRYPTO_SM4
> +#include <nettle/sm4.h>
> +#endif
>   
>   static inline bool qcrypto_length_check(size_t len, size_t blocksize,
>                                           Error **errp)
> @@ -426,6 +429,30 @@ DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_twofish,
>                          QCryptoNettleTwofish, TWOFISH_BLOCK_SIZE,
>                          twofish_encrypt_native, twofish_decrypt_native)
>   
> +#ifdef CONFIG_CRYPTO_SM4
> +typedef struct QCryptoNettleSm4 {
> +    QCryptoCipher base;
> +    struct sm4_ctx key[2];
> +} QCryptoNettleSm4;
> +
> +static void sm4_encrypt_native(void *ctx, size_t length,
> +                               uint8_t *dst, const uint8_t *src)
> +{
> +    struct sm4_ctx *keys = ctx;
> +    sm4_crypt(&keys[0], length, dst, src);
> +}
> +
> +static void sm4_decrypt_native(void *ctx, size_t length,
> +                               uint8_t *dst, const uint8_t *src)
> +{
> +    struct sm4_ctx *keys = ctx;
> +    sm4_crypt(&keys[1], length, dst, src);
> +}
> +
> +DEFINE_ECB(qcrypto_nettle_sm4,
> +           QCryptoNettleSm4, SM4_BLOCK_SIZE,
> +           sm4_encrypt_native, sm4_decrypt_native)
> +#endif
>   
>   bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
>                                QCryptoCipherMode mode)
> @@ -443,6 +470,9 @@ bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
>       case QCRYPTO_CIPHER_ALG_TWOFISH_128:
>       case QCRYPTO_CIPHER_ALG_TWOFISH_192:
>       case QCRYPTO_CIPHER_ALG_TWOFISH_256:
> +#ifdef CONFIG_CRYPTO_SM4
> +    case QCRYPTO_CIPHER_ALG_SM4:
> +#endif
>           break;
>       default:
>           return false;
> @@ -701,6 +731,25 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
>   
>               return &ctx->base;
>           }
> +#ifdef CONFIG_CRYPTO_SM4
> +    case QCRYPTO_CIPHER_ALG_SM4:
> +        {
> +            QCryptoNettleSm4 *ctx = g_new0(QCryptoNettleSm4, 1);
> +
> +            switch (mode) {
> +            case QCRYPTO_CIPHER_MODE_ECB:
> +                ctx->base.driver = &qcrypto_nettle_sm4_driver_ecb;
> +                break;
> +            default:
> +                goto bad_cipher_mode;
> +            }
> +
> +            sm4_set_encrypt_key(&ctx->key[0], key);
> +            sm4_set_decrypt_key(&ctx->key[1], key);
> +
> +            return &ctx->base;
> +        }
> +#endif
>   
>       default:
>           error_setg(errp, "Unsupported cipher algorithm %s",
> diff --git a/crypto/cipher.c b/crypto/cipher.c
> index 74b09a5b26..5f512768ea 100644
> --- a/crypto/cipher.c
> +++ b/crypto/cipher.c
> @@ -38,6 +38,9 @@ static const size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = {
>       [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
>       [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 24,
>       [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 32,
> +#ifdef CONFIG_CRYPTO_SM4
> +    [QCRYPTO_CIPHER_ALG_SM4] = 16,
> +#endif
>   };
>   
>   static const size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = {
> @@ -53,6 +56,9 @@ static const size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = {
>       [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
>       [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 16,
>       [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 16,
> +#ifdef CONFIG_CRYPTO_SM4
> +    [QCRYPTO_CIPHER_ALG_SM4] = 16,
> +#endif
>   };
>   
>   static const bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
> diff --git a/meson.build b/meson.build
> index d2c4c2adb3..52f2f85b5a 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1480,6 +1480,7 @@ endif
>   gcrypt = not_found
>   nettle = not_found
>   hogweed = not_found
> +crypto_sm4 = not_found
>   xts = 'none'
>   
>   if get_option('nettle').enabled() and get_option('gcrypt').enabled()
> @@ -1505,6 +1506,17 @@ if not gnutls_crypto.found()
>            cc.find_library('gpg-error', required: true)],
>           version: gcrypt.version())
>       endif
> +    crypto_sm4 = gcrypt
> +    # SM4 ALG is available in libgcrypt >= 1.9
> +    if gcrypt.found() and not cc.links('''
> +      #include <gcrypt.h>
> +      int main(void) {
> +        gcry_cipher_hd_t handler;
> +        gcry_cipher_open(&handler, GCRY_CIPHER_SM4, GCRY_CIPHER_MODE_ECB, 0);
> +        return 0;
> +      }''', dependencies: gcrypt)
> +      crypto_sm4 = not_found
> +    endif
>     endif
>     if (not get_option('nettle').auto() or have_system) and not gcrypt.found()
>       nettle = dependency('nettle', version: '>=3.4',
> @@ -1513,6 +1525,18 @@ if not gnutls_crypto.found()
>       if nettle.found() and not cc.has_header('nettle/xts.h', dependencies: nettle)
>         xts = 'private'
>       endif
> +    crypto_sm4 = nettle
> +    # SM4 ALG is available in nettle >= 3.9
> +    if nettle.found() and not cc.links('''
> +      #include <nettle/sm4.h>
> +      int main(void) {
> +        struct sm4_ctx ctx;
> +        unsigned char key[16] = {0};
> +        sm4_set_encrypt_key(&ctx, key);
> +        return 0;
> +      }''', dependencies: nettle)
> +      crypto_sm4 = not_found
> +    endif
>     endif
>   endif
>   
> @@ -2199,6 +2223,7 @@ config_host_data.set('CONFIG_GNUTLS_CRYPTO', gnutls_crypto.found())
>   config_host_data.set('CONFIG_TASN1', tasn1.found())
>   config_host_data.set('CONFIG_GCRYPT', gcrypt.found())
>   config_host_data.set('CONFIG_NETTLE', nettle.found())
> +config_host_data.set('CONFIG_CRYPTO_SM4', crypto_sm4.found())
>   config_host_data.set('CONFIG_HOGWEED', hogweed.found())
>   config_host_data.set('CONFIG_QEMU_PRIVATE_XTS', xts == 'private')
>   config_host_data.set('CONFIG_MALLOC_TRIM', has_malloc_trim)
> @@ -4274,6 +4299,7 @@ summary_info += {'nettle':            nettle}
>   if nettle.found()
>      summary_info += {'  XTS':             xts != 'private'}
>   endif
> +summary_info += {'SM4 ALG support':   crypto_sm4}
>   summary_info += {'AF_ALG support':    have_afalg}
>   summary_info += {'rng-none':          get_option('rng_none')}
>   summary_info += {'Linux keyring':     have_keyring}
> diff --git a/qapi/crypto.json b/qapi/crypto.json
> index fd3d46ebd1..2f2aeff5fd 100644
> --- a/qapi/crypto.json
> +++ b/qapi/crypto.json
> @@ -94,6 +94,8 @@
>   #
>   # @twofish-256: Twofish with 256 bit / 32 byte keys
>   #
> +# @sm4: SM4 with 128 bit / 16 byte keys (since 9.0)
> +#
>   # Since: 2.6
>   ##
>   { 'enum': 'QCryptoCipherAlgorithm',
> @@ -102,7 +104,8 @@
>              'des', '3des',
>              'cast5-128',
>              'serpent-128', 'serpent-192', 'serpent-256',
> -           'twofish-128', 'twofish-192', 'twofish-256']}
> +           'twofish-128', 'twofish-192', 'twofish-256',
> +           'sm4']}
>   
>   ##
>   # @QCryptoCipherMode:
> diff --git a/tests/unit/test-crypto-cipher.c b/tests/unit/test-crypto-cipher.c
> index d9d9d078ff..11ab1a54fc 100644
> --- a/tests/unit/test-crypto-cipher.c
> +++ b/tests/unit/test-crypto-cipher.c
> @@ -382,6 +382,19 @@ static QCryptoCipherTestData test_data[] = {
>           .plaintext = "90afe91bb288544f2c32dc239b2635e6",
>           .ciphertext = "6cb4561c40bf0a9705931cb6d408e7fa",
>       },
> +#ifdef CONFIG_CRYPTO_SM4
> +    {
> +        /* SM4, GB/T 32907-2016, Appendix A.1 */
> +        .path = "/crypto/cipher/sm4",
> +        .alg = QCRYPTO_CIPHER_ALG_SM4,
> +        .mode = QCRYPTO_CIPHER_MODE_ECB,
> +        .key = "0123456789abcdeffedcba9876543210",
> +        .plaintext  =
> +            "0123456789abcdeffedcba9876543210",
> +        .ciphertext =
> +            "681edf34d206965e86b3e94f536e4246",
> +    },
> +#endif
>       {
>           /* #1 32 byte key, 32 byte PTX */
>           .path = "/crypto/cipher/aes-xts-128-1",