diff options
Diffstat (limited to 'crypto/cipher-gcrypt.c')
| -rw-r--r-- | crypto/cipher-gcrypt.c | 123 |
1 files changed, 98 insertions, 25 deletions
diff --git a/crypto/cipher-gcrypt.c b/crypto/cipher-gcrypt.c index ce26456460..ede2f70df8 100644 --- a/crypto/cipher-gcrypt.c +++ b/crypto/cipher-gcrypt.c @@ -19,6 +19,8 @@ */ #include "qemu/osdep.h" +#include "crypto/xts.h" + #include <gcrypt.h> @@ -44,7 +46,9 @@ bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg) typedef struct QCryptoCipherGcrypt QCryptoCipherGcrypt; struct QCryptoCipherGcrypt { gcry_cipher_hd_t handle; + gcry_cipher_hd_t tweakhandle; size_t blocksize; + uint8_t *iv; }; QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, @@ -59,6 +63,7 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, switch (mode) { case QCRYPTO_CIPHER_MODE_ECB: + case QCRYPTO_CIPHER_MODE_XTS: gcrymode = GCRY_CIPHER_MODE_ECB; break; case QCRYPTO_CIPHER_MODE_CBC: @@ -69,7 +74,7 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, return NULL; } - if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) { + if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) { return NULL; } @@ -131,6 +136,14 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, gcry_strerror(err)); goto error; } + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + err = gcry_cipher_open(&ctx->tweakhandle, gcryalg, gcrymode, 0); + if (err != 0) { + error_setg(errp, "Cannot initialize cipher: %s", + gcry_strerror(err)); + goto error; + } + } if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) { /* We're using standard DES cipher from gcrypt, so we need @@ -142,7 +155,23 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, g_free(rfbkey); ctx->blocksize = 8; } else { - err = gcry_cipher_setkey(ctx->handle, key, nkey); + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + nkey /= 2; + err = gcry_cipher_setkey(ctx->handle, key, nkey); + if (err != 0) { + error_setg(errp, "Cannot set key: %s", + gcry_strerror(err)); + goto error; + } + err = gcry_cipher_setkey(ctx->tweakhandle, key + nkey, nkey); + } else { + err = gcry_cipher_setkey(ctx->handle, key, nkey); + } + if (err != 0) { + error_setg(errp, "Cannot set key: %s", + gcry_strerror(err)); + goto error; + } switch (cipher->alg) { case QCRYPTO_CIPHER_ALG_AES_128: case QCRYPTO_CIPHER_ALG_AES_192: @@ -161,10 +190,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, g_assert_not_reached(); } } - if (err != 0) { - error_setg(errp, "Cannot set key: %s", - gcry_strerror(err)); - goto error; + + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + ctx->iv = g_new0(uint8_t, ctx->blocksize); } cipher->opaque = ctx; @@ -172,6 +200,9 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, error: gcry_cipher_close(ctx->handle); + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + gcry_cipher_close(ctx->tweakhandle); + } g_free(ctx); g_free(cipher); return NULL; @@ -186,11 +217,35 @@ void qcrypto_cipher_free(QCryptoCipher *cipher) } ctx = cipher->opaque; gcry_cipher_close(ctx->handle); + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + gcry_cipher_close(ctx->tweakhandle); + } + g_free(ctx->iv); g_free(ctx); g_free(cipher); } +static void qcrypto_gcrypt_xts_encrypt(const void *ctx, + size_t length, + uint8_t *dst, + const uint8_t *src) +{ + gcry_error_t err; + err = gcry_cipher_encrypt((gcry_cipher_hd_t)ctx, dst, length, src, length); + g_assert(err == 0); +} + +static void qcrypto_gcrypt_xts_decrypt(const void *ctx, + size_t length, + uint8_t *dst, + const uint8_t *src) +{ + gcry_error_t err; + err = gcry_cipher_decrypt((gcry_cipher_hd_t)ctx, dst, length, src, length); + g_assert(err == 0); +} + int qcrypto_cipher_encrypt(QCryptoCipher *cipher, const void *in, void *out, @@ -206,13 +261,20 @@ int qcrypto_cipher_encrypt(QCryptoCipher *cipher, return -1; } - err = gcry_cipher_encrypt(ctx->handle, - out, len, - in, len); - if (err != 0) { - error_setg(errp, "Cannot encrypt data: %s", - gcry_strerror(err)); - return -1; + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + xts_encrypt(ctx->handle, ctx->tweakhandle, + qcrypto_gcrypt_xts_encrypt, + qcrypto_gcrypt_xts_decrypt, + ctx->iv, len, out, in); + } else { + err = gcry_cipher_encrypt(ctx->handle, + out, len, + in, len); + if (err != 0) { + error_setg(errp, "Cannot encrypt data: %s", + gcry_strerror(err)); + return -1; + } } return 0; @@ -234,13 +296,20 @@ int qcrypto_cipher_decrypt(QCryptoCipher *cipher, return -1; } - err = gcry_cipher_decrypt(ctx->handle, - out, len, - in, len); - if (err != 0) { - error_setg(errp, "Cannot decrypt data: %s", - gcry_strerror(err)); - return -1; + if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) { + xts_decrypt(ctx->handle, ctx->tweakhandle, + qcrypto_gcrypt_xts_encrypt, + qcrypto_gcrypt_xts_decrypt, + ctx->iv, len, out, in); + } else { + err = gcry_cipher_decrypt(ctx->handle, + out, len, + in, len); + if (err != 0) { + error_setg(errp, "Cannot decrypt data: %s", + gcry_strerror(err)); + return -1; + } } return 0; @@ -259,12 +328,16 @@ int qcrypto_cipher_setiv(QCryptoCipher *cipher, return -1; } - gcry_cipher_reset(ctx->handle); - err = gcry_cipher_setiv(ctx->handle, iv, niv); - if (err != 0) { - error_setg(errp, "Cannot set IV: %s", + 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; + return -1; + } } return 0; |