]> git.proxmox.com Git - mirror_qemu.git/blobdiff - crypto/cipher-gcrypt.c
qapi: Mechanically convert FOO_lookup[...] to FOO_str(...)
[mirror_qemu.git] / crypto / cipher-gcrypt.c
index 56d4c9d10b78cad68df5841056af2f1725d3074a..10d75da75da2cedc536ed1055e3f5106a111444b 100644 (file)
  */
 
 #include "qemu/osdep.h"
+#include "crypto/xts.h"
+#include "cipherpriv.h"
+
 #include <gcrypt.h>
 
 
-bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg)
+bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
+                             QCryptoCipherMode mode)
 {
     switch (alg) {
     case QCRYPTO_CIPHER_ALG_DES_RFB:
+    case QCRYPTO_CIPHER_ALG_3DES:
     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:
+        break;
+    default:
+        return false;
+    }
+
+    switch (mode) {
+    case QCRYPTO_CIPHER_MODE_ECB:
+    case QCRYPTO_CIPHER_MODE_CBC:
+    case QCRYPTO_CIPHER_MODE_XTS:
+    case QCRYPTO_CIPHER_MODE_CTR:
         return true;
     default:
         return false;
@@ -38,32 +59,57 @@ 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;
+    /* Initialization vector or Counter */
+    uint8_t *iv;
 };
 
-QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
-                                  QCryptoCipherMode mode,
-                                  const uint8_t *key, size_t nkey,
-                                  Error **errp)
+static void
+qcrypto_gcrypt_cipher_free_ctx(QCryptoCipherGcrypt *ctx,
+                               QCryptoCipherMode mode)
+{
+    if (!ctx) {
+        return;
+    }
+
+    gcry_cipher_close(ctx->handle);
+    if (mode == QCRYPTO_CIPHER_MODE_XTS) {
+        gcry_cipher_close(ctx->tweakhandle);
+    }
+    g_free(ctx->iv);
+    g_free(ctx);
+}
+
+
+static QCryptoCipherGcrypt *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
+                                                   QCryptoCipherMode mode,
+                                                   const uint8_t *key,
+                                                   size_t nkey,
+                                                   Error **errp)
 {
-    QCryptoCipher *cipher;
     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:
         gcrymode = GCRY_CIPHER_MODE_CBC;
         break;
+    case QCRYPTO_CIPHER_MODE_CTR:
+        gcrymode = GCRY_CIPHER_MODE_CTR;
+        break;
     default:
-        error_setg(errp, "Unsupported cipher mode %d", mode);
+        error_setg(errp, "Unsupported cipher mode %s",
+                   QCryptoCipherMode_str(mode));
         return NULL;
     }
 
-    if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) {
+    if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
         return NULL;
     }
 
@@ -72,6 +118,10 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
         gcryalg = GCRY_CIPHER_DES;
         break;
 
+    case QCRYPTO_CIPHER_ALG_3DES:
+        gcryalg = GCRY_CIPHER_3DES;
+        break;
+
     case QCRYPTO_CIPHER_ALG_AES_128:
         gcryalg = GCRY_CIPHER_AES128;
         break;
@@ -84,15 +134,36 @@ 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);
+        error_setg(errp, "Unsupported cipher algorithm %s",
+                   QCryptoCipherAlgorithm_str(alg));
         return NULL;
     }
 
-    cipher = g_new0(QCryptoCipher, 1);
-    cipher->alg = alg;
-    cipher->mode = mode;
-
     ctx = g_new0(QCryptoCipherGcrypt, 1);
 
     err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
@@ -101,8 +172,16 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
                    gcry_strerror(err));
         goto error;
     }
+    if (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) {
+    if (alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
         /* We're using standard DES cipher from gcrypt, so we need
          * to munge the key so that the results are the same as the
          * bizarre RFB variant of DES :-)
@@ -112,44 +191,94 @@ QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
         g_free(rfbkey);
         ctx->blocksize = 8;
     } else {
-        err = gcry_cipher_setkey(ctx->handle, key, nkey);
-        ctx->blocksize = 16;
+        if (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 (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_3DES:
+        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 (mode == QCRYPTO_CIPHER_MODE_XTS) {
+        if (ctx->blocksize != XTS_BLOCK_SIZE) {
+            error_setg(errp,
+                       "Cipher block size %zu must equal XTS block size %d",
+                       ctx->blocksize, XTS_BLOCK_SIZE);
+            goto error;
+        }
+        ctx->iv = g_new0(uint8_t, ctx->blocksize);
     }
 
-    cipher->opaque = ctx;
-    return cipher;
+    return ctx;
 
  error:
-    gcry_cipher_close(ctx->handle);
-    g_free(ctx);
-    g_free(cipher);
+    qcrypto_gcrypt_cipher_free_ctx(ctx, mode);
     return NULL;
 }
 
 
-void qcrypto_cipher_free(QCryptoCipher *cipher)
+static void
+qcrypto_gcrypt_cipher_ctx_free(QCryptoCipher *cipher)
 {
-    QCryptoCipherGcrypt *ctx;
-    if (!cipher) {
-        return;
-    }
-    ctx = cipher->opaque;
-    gcry_cipher_close(ctx->handle);
-    g_free(ctx);
-    g_free(cipher);
+    qcrypto_gcrypt_cipher_free_ctx(cipher->opaque, cipher->mode);
 }
 
 
-int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
-                           const void *in,
-                           void *out,
-                           size_t len,
-                           Error **errp)
+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);
+}
+
+static int
+qcrypto_gcrypt_cipher_encrypt(QCryptoCipher *cipher,
+                              const void *in,
+                              void *out,
+                              size_t len,
+                              Error **errp)
 {
     QCryptoCipherGcrypt *ctx = cipher->opaque;
     gcry_error_t err;
@@ -160,24 +289,32 @@ 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;
 }
 
 
-int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
-                           const void *in,
-                           void *out,
-                           size_t len,
-                           Error **errp)
+static int
+qcrypto_gcrypt_cipher_decrypt(QCryptoCipher *cipher,
+                              const void *in,
+                              void *out,
+                              size_t len,
+                              Error **errp)
 {
     QCryptoCipherGcrypt *ctx = cipher->opaque;
     gcry_error_t err;
@@ -188,21 +325,29 @@ 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;
 }
 
-int qcrypto_cipher_setiv(QCryptoCipher *cipher,
-                         const uint8_t *iv, size_t niv,
-                         Error **errp)
+static int
+qcrypto_gcrypt_cipher_setiv(QCryptoCipher *cipher,
+                            const uint8_t *iv, size_t niv,
+                            Error **errp)
 {
     QCryptoCipherGcrypt *ctx = cipher->opaque;
     gcry_error_t err;
@@ -213,13 +358,34 @@ 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",
-                   gcry_strerror(err));
-        return -1;
+    if (ctx->iv) {
+        memcpy(ctx->iv, iv, niv);
+    } else {
+        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;
+            }
+        }
     }
 
     return 0;
 }
+
+
+static struct QCryptoCipherDriver qcrypto_cipher_lib_driver = {
+    .cipher_encrypt = qcrypto_gcrypt_cipher_encrypt,
+    .cipher_decrypt = qcrypto_gcrypt_cipher_decrypt,
+    .cipher_setiv = qcrypto_gcrypt_cipher_setiv,
+    .cipher_free = qcrypto_gcrypt_cipher_ctx_free,
+};