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

[Daniel P . Berrangé]

On Fri, Mar 08, 2024 at 09:30:52PM +0100, Thomas Huth wrote:
> 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...

Or more worringly the issue could be in nettle's impl of SM4, as
I'm not seeing an obvious place in this QEMU glue layer which
could cause endianness mistakes.

> 
>  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",
> 

With regards,
Daniel
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