diff options
Diffstat (limited to 'qemu/crypto/cipher-gcrypt.c')
| -rw-r--r-- | qemu/crypto/cipher-gcrypt.c | 217 |
1 files changed, 183 insertions, 34 deletions
diff --git a/qemu/crypto/cipher-gcrypt.c b/qemu/crypto/cipher-gcrypt.c index 8cfc56250..ede2f70df 100644 --- a/qemu/crypto/cipher-gcrypt.c +++ b/qemu/crypto/cipher-gcrypt.c @@ -18,6 +18,9 @@ * */ +#include "qemu/osdep.h" +#include "crypto/xts.h" + #include <gcrypt.h> @@ -28,12 +31,25 @@ bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg) case QCRYPTO_CIPHER_ALG_AES_128: case QCRYPTO_CIPHER_ALG_AES_192: case QCRYPTO_CIPHER_ALG_AES_256: + case QCRYPTO_CIPHER_ALG_CAST5_128: + case QCRYPTO_CIPHER_ALG_SERPENT_128: + case QCRYPTO_CIPHER_ALG_SERPENT_192: + case QCRYPTO_CIPHER_ALG_SERPENT_256: + case QCRYPTO_CIPHER_ALG_TWOFISH_128: + case QCRYPTO_CIPHER_ALG_TWOFISH_256: return true; default: return false; } } +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, QCryptoCipherMode mode, @@ -41,12 +57,13 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, Error **errp) { QCryptoCipher *cipher; - gcry_cipher_hd_t handle; + QCryptoCipherGcrypt *ctx; gcry_error_t err; int gcryalg, gcrymode; switch (mode) { case QCRYPTO_CIPHER_MODE_ECB: + case QCRYPTO_CIPHER_MODE_XTS: gcrymode = GCRY_CIPHER_MODE_ECB; break; case QCRYPTO_CIPHER_MODE_CBC: @@ -57,7 +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; } @@ -78,6 +95,30 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, gcryalg = GCRY_CIPHER_AES256; break; + case QCRYPTO_CIPHER_ALG_CAST5_128: + gcryalg = GCRY_CIPHER_CAST5; + break; + + case QCRYPTO_CIPHER_ALG_SERPENT_128: + gcryalg = GCRY_CIPHER_SERPENT128; + break; + + case QCRYPTO_CIPHER_ALG_SERPENT_192: + gcryalg = GCRY_CIPHER_SERPENT192; + break; + + case QCRYPTO_CIPHER_ALG_SERPENT_256: + gcryalg = GCRY_CIPHER_SERPENT256; + break; + + case QCRYPTO_CIPHER_ALG_TWOFISH_128: + gcryalg = GCRY_CIPHER_TWOFISH128; + break; + + case QCRYPTO_CIPHER_ALG_TWOFISH_256: + gcryalg = GCRY_CIPHER_TWOFISH; + break; + default: error_setg(errp, "Unsupported cipher algorithm %d", alg); return NULL; @@ -87,12 +128,22 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, cipher->alg = alg; cipher->mode = mode; - err = gcry_cipher_open(&handle, gcryalg, gcrymode, 0); + ctx = g_new0(QCryptoCipherGcrypt, 1); + + err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0); if (err != 0) { error_setg(errp, "Cannot initialize cipher: %s", 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 @@ -100,22 +151,59 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, * bizarre RFB variant of DES :-) */ uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey); - err = gcry_cipher_setkey(handle, rfbkey, nkey); + err = gcry_cipher_setkey(ctx->handle, rfbkey, nkey); g_free(rfbkey); + ctx->blocksize = 8; } else { - err = gcry_cipher_setkey(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: + case QCRYPTO_CIPHER_ALG_AES_256: + case QCRYPTO_CIPHER_ALG_SERPENT_128: + case QCRYPTO_CIPHER_ALG_SERPENT_192: + case QCRYPTO_CIPHER_ALG_SERPENT_256: + case QCRYPTO_CIPHER_ALG_TWOFISH_128: + case QCRYPTO_CIPHER_ALG_TWOFISH_256: + ctx->blocksize = 16; + break; + case QCRYPTO_CIPHER_ALG_CAST5_128: + ctx->blocksize = 8; + break; + default: + 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 = handle; + cipher->opaque = ctx; return cipher; error: - gcry_cipher_close(handle); + 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; } @@ -123,34 +211,72 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, void qcrypto_cipher_free(QCryptoCipher *cipher) { - gcry_cipher_hd_t handle; + QCryptoCipherGcrypt *ctx; if (!cipher) { return; } - handle = cipher->opaque; - gcry_cipher_close(handle); + 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, size_t len, Error **errp) { - gcry_cipher_hd_t handle = cipher->opaque; + QCryptoCipherGcrypt *ctx = cipher->opaque; gcry_error_t err; - err = gcry_cipher_encrypt(handle, - out, len, - in, len); - if (err != 0) { - error_setg(errp, "Cannot encrypt data: %s", - gcry_strerror(err)); + if (len % ctx->blocksize) { + error_setg(errp, "Length %zu must be a multiple of block size %zu", + len, ctx->blocksize); 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; } @@ -161,18 +287,31 @@ int qcrypto_cipher_decrypt(QCryptoCipher *cipher, size_t len, Error **errp) { - gcry_cipher_hd_t handle = cipher->opaque; + QCryptoCipherGcrypt *ctx = cipher->opaque; gcry_error_t err; - err = gcry_cipher_decrypt(handle, - out, len, - in, len); - if (err != 0) { - error_setg(errp, "Cannot decrypt data: %s", - gcry_strerror(err)); + if (len % ctx->blocksize) { + error_setg(errp, "Length %zu must be a multiple of block size %zu", + len, ctx->blocksize); 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; } @@ -180,16 +319,26 @@ int qcrypto_cipher_setiv(QCryptoCipher *cipher, const uint8_t *iv, size_t niv, Error **errp) { - gcry_cipher_hd_t handle = cipher->opaque; + QCryptoCipherGcrypt *ctx = cipher->opaque; gcry_error_t err; - gcry_cipher_reset(handle); - err = gcry_cipher_setiv(handle, iv, niv); - if (err != 0) { - error_setg(errp, "Cannot set IV: %s", - gcry_strerror(err)); + if (niv != ctx->blocksize) { + error_setg(errp, "Expected IV size %zu not %zu", + ctx->blocksize, niv); return -1; } + 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 0; } |