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-rw-r--r--crypto/secret.c513
1 files changed, 513 insertions, 0 deletions
diff --git a/crypto/secret.c b/crypto/secret.c
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index 0000000..9a9257a
--- /dev/null
+++ b/crypto/secret.c
@@ -0,0 +1,513 @@
+/*
+ * QEMU crypto secret support
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "crypto/secret.h"
+#include "crypto/cipher.h"
+#include "qom/object_interfaces.h"
+#include "qemu/base64.h"
+#include "trace.h"
+
+
+static void
+qcrypto_secret_load_data(QCryptoSecret *secret,
+ uint8_t **output,
+ size_t *outputlen,
+ Error **errp)
+{
+ char *data = NULL;
+ size_t length = 0;
+ GError *gerr = NULL;
+
+ *output = NULL;
+ *outputlen = 0;
+
+ if (secret->file) {
+ if (secret->data) {
+ error_setg(errp,
+ "'file' and 'data' are mutually exclusive");
+ return;
+ }
+ if (!g_file_get_contents(secret->file, &data, &length, &gerr)) {
+ error_setg(errp,
+ "Unable to read %s: %s",
+ secret->file, gerr->message);
+ g_error_free(gerr);
+ return;
+ }
+ *output = (uint8_t *)data;
+ *outputlen = length;
+ } else if (secret->data) {
+ *outputlen = strlen(secret->data);
+ *output = (uint8_t *)g_strdup(secret->data);
+ } else {
+ error_setg(errp, "Either 'file' or 'data' must be provided");
+ }
+}
+
+
+static void qcrypto_secret_decrypt(QCryptoSecret *secret,
+ const uint8_t *input,
+ size_t inputlen,
+ uint8_t **output,
+ size_t *outputlen,
+ Error **errp)
+{
+ uint8_t *key = NULL, *ciphertext = NULL, *iv = NULL;
+ size_t keylen, ciphertextlen, ivlen;
+ QCryptoCipher *aes = NULL;
+ uint8_t *plaintext = NULL;
+
+ *output = NULL;
+ *outputlen = 0;
+
+ if (qcrypto_secret_lookup(secret->keyid,
+ &key, &keylen,
+ errp) < 0) {
+ goto cleanup;
+ }
+
+ if (keylen != 32) {
+ error_setg(errp, "Key should be 32 bytes in length");
+ goto cleanup;
+ }
+
+ if (!secret->iv) {
+ error_setg(errp, "IV is required to decrypt secret");
+ goto cleanup;
+ }
+
+ iv = qbase64_decode(secret->iv, -1, &ivlen, errp);
+ if (!iv) {
+ goto cleanup;
+ }
+ if (ivlen != 16) {
+ error_setg(errp, "IV should be 16 bytes in length not %zu",
+ ivlen);
+ goto cleanup;
+ }
+
+ aes = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_256,
+ QCRYPTO_CIPHER_MODE_CBC,
+ key, keylen,
+ errp);
+ if (!aes) {
+ goto cleanup;
+ }
+
+ if (qcrypto_cipher_setiv(aes, iv, ivlen, errp) < 0) {
+ goto cleanup;
+ }
+
+ if (secret->format == QCRYPTO_SECRET_FORMAT_BASE64) {
+ ciphertext = qbase64_decode((const gchar*)input,
+ inputlen,
+ &ciphertextlen,
+ errp);
+ if (!ciphertext) {
+ goto cleanup;
+ }
+ plaintext = g_new0(uint8_t, ciphertextlen + 1);
+ } else {
+ ciphertextlen = inputlen;
+ plaintext = g_new0(uint8_t, inputlen + 1);
+ }
+ if (qcrypto_cipher_decrypt(aes,
+ ciphertext ? ciphertext : input,
+ plaintext,
+ ciphertextlen,
+ errp) < 0) {
+ plaintext = NULL;
+ goto cleanup;
+ }
+
+ if (plaintext[ciphertextlen - 1] > 16 ||
+ plaintext[ciphertextlen - 1] > ciphertextlen) {
+ error_setg(errp, "Incorrect number of padding bytes (%d) "
+ "found on decrypted data",
+ (int)plaintext[ciphertextlen - 1]);
+ g_free(plaintext);
+ plaintext = NULL;
+ goto cleanup;
+ }
+
+ /* Even though plaintext may contain arbitrary NUL
+ * ensure it is explicitly NUL terminated.
+ */
+ ciphertextlen -= plaintext[ciphertextlen - 1];
+ plaintext[ciphertextlen] = '\0';
+
+ *output = plaintext;
+ *outputlen = ciphertextlen;
+
+ cleanup:
+ g_free(ciphertext);
+ g_free(iv);
+ g_free(key);
+ qcrypto_cipher_free(aes);
+}
+
+
+static void qcrypto_secret_decode(const uint8_t *input,
+ size_t inputlen,
+ uint8_t **output,
+ size_t *outputlen,
+ Error **errp)
+{
+ *output = qbase64_decode((const gchar*)input,
+ inputlen,
+ outputlen,
+ errp);
+}
+
+
+static void
+qcrypto_secret_prop_set_loaded(Object *obj,
+ bool value,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+
+ if (value) {
+ Error *local_err = NULL;
+ uint8_t *input = NULL;
+ size_t inputlen = 0;
+ uint8_t *output = NULL;
+ size_t outputlen = 0;
+
+ qcrypto_secret_load_data(secret, &input, &inputlen, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ if (secret->keyid) {
+ qcrypto_secret_decrypt(secret, input, inputlen,
+ &output, &outputlen, &local_err);
+ g_free(input);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ input = output;
+ inputlen = outputlen;
+ } else {
+ if (secret->format != QCRYPTO_SECRET_FORMAT_RAW) {
+ qcrypto_secret_decode(input, inputlen,
+ &output, &outputlen, &local_err);
+ g_free(input);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ input = output;
+ inputlen = outputlen;
+ }
+ }
+
+ secret->rawdata = input;
+ secret->rawlen = inputlen;
+ } else {
+ g_free(secret->rawdata);
+ secret->rawlen = 0;
+ }
+}
+
+
+static bool
+qcrypto_secret_prop_get_loaded(Object *obj,
+ Error **errp G_GNUC_UNUSED)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+ return secret->data != NULL;
+}
+
+
+static void
+qcrypto_secret_prop_set_format(Object *obj,
+ int value,
+ Error **errp G_GNUC_UNUSED)
+{
+ QCryptoSecret *creds = QCRYPTO_SECRET(obj);
+
+ creds->format = value;
+}
+
+
+static int
+qcrypto_secret_prop_get_format(Object *obj,
+ Error **errp G_GNUC_UNUSED)
+{
+ QCryptoSecret *creds = QCRYPTO_SECRET(obj);
+
+ return creds->format;
+}
+
+
+static void
+qcrypto_secret_prop_set_data(Object *obj,
+ const char *value,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+
+ g_free(secret->data);
+ secret->data = g_strdup(value);
+}
+
+
+static char *
+qcrypto_secret_prop_get_data(Object *obj,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+ return g_strdup(secret->data);
+}
+
+
+static void
+qcrypto_secret_prop_set_file(Object *obj,
+ const char *value,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+
+ g_free(secret->file);
+ secret->file = g_strdup(value);
+}
+
+
+static char *
+qcrypto_secret_prop_get_file(Object *obj,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+ return g_strdup(secret->file);
+}
+
+
+static void
+qcrypto_secret_prop_set_iv(Object *obj,
+ const char *value,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+
+ g_free(secret->iv);
+ secret->iv = g_strdup(value);
+}
+
+
+static char *
+qcrypto_secret_prop_get_iv(Object *obj,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+ return g_strdup(secret->iv);
+}
+
+
+static void
+qcrypto_secret_prop_set_keyid(Object *obj,
+ const char *value,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+
+ g_free(secret->keyid);
+ secret->keyid = g_strdup(value);
+}
+
+
+static char *
+qcrypto_secret_prop_get_keyid(Object *obj,
+ Error **errp)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+ return g_strdup(secret->keyid);
+}
+
+
+static void
+qcrypto_secret_complete(UserCreatable *uc, Error **errp)
+{
+ object_property_set_bool(OBJECT(uc), true, "loaded", errp);
+}
+
+
+static void
+qcrypto_secret_init(Object *obj)
+{
+ object_property_add_bool(obj, "loaded",
+ qcrypto_secret_prop_get_loaded,
+ qcrypto_secret_prop_set_loaded,
+ NULL);
+ object_property_add_enum(obj, "format",
+ "QCryptoSecretFormat",
+ QCryptoSecretFormat_lookup,
+ qcrypto_secret_prop_get_format,
+ qcrypto_secret_prop_set_format,
+ NULL);
+ object_property_add_str(obj, "data",
+ qcrypto_secret_prop_get_data,
+ qcrypto_secret_prop_set_data,
+ NULL);
+ object_property_add_str(obj, "file",
+ qcrypto_secret_prop_get_file,
+ qcrypto_secret_prop_set_file,
+ NULL);
+ object_property_add_str(obj, "keyid",
+ qcrypto_secret_prop_get_keyid,
+ qcrypto_secret_prop_set_keyid,
+ NULL);
+ object_property_add_str(obj, "iv",
+ qcrypto_secret_prop_get_iv,
+ qcrypto_secret_prop_set_iv,
+ NULL);
+}
+
+
+static void
+qcrypto_secret_finalize(Object *obj)
+{
+ QCryptoSecret *secret = QCRYPTO_SECRET(obj);
+
+ g_free(secret->iv);
+ g_free(secret->file);
+ g_free(secret->keyid);
+ g_free(secret->rawdata);
+ g_free(secret->data);
+}
+
+static void
+qcrypto_secret_class_init(ObjectClass *oc, void *data)
+{
+ UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+ ucc->complete = qcrypto_secret_complete;
+}
+
+
+int qcrypto_secret_lookup(const char *secretid,
+ uint8_t **data,
+ size_t *datalen,
+ Error **errp)
+{
+ Object *obj;
+ QCryptoSecret *secret;
+
+ obj = object_resolve_path_component(
+ object_get_objects_root(), secretid);
+ if (!obj) {
+ error_setg(errp, "No secret with id '%s'", secretid);
+ return -1;
+ }
+
+ secret = (QCryptoSecret *)
+ object_dynamic_cast(obj,
+ TYPE_QCRYPTO_SECRET);
+ if (!secret) {
+ error_setg(errp, "Object with id '%s' is not a secret",
+ secretid);
+ return -1;
+ }
+
+ if (!secret->rawdata) {
+ error_setg(errp, "Secret with id '%s' has no data",
+ secretid);
+ return -1;
+ }
+
+ *data = g_new0(uint8, secret->rawlen + 1);
+ memcpy(*data, secret->rawdata, secret->rawlen);
+ (*data)[secret->rawlen] = '\0';
+ *datalen = secret->rawlen;
+
+ return 0;
+}
+
+
+char *qcrypto_secret_lookup_as_utf8(const char *secretid,
+ Error **errp)
+{
+ uint8_t *data;
+ size_t datalen;
+
+ if (qcrypto_secret_lookup(secretid,
+ &data,
+ &datalen,
+ errp) < 0) {
+ return NULL;
+ }
+
+ if (!g_utf8_validate((const gchar*)data, datalen, NULL)) {
+ error_setg(errp,
+ "Data from secret %s is not valid UTF-8",
+ secretid);
+ g_free(data);
+ return NULL;
+ }
+
+ return (char *)data;
+}
+
+
+char *qcrypto_secret_lookup_as_base64(const char *secretid,
+ Error **errp)
+{
+ uint8_t *data;
+ size_t datalen;
+ char *ret;
+
+ if (qcrypto_secret_lookup(secretid,
+ &data,
+ &datalen,
+ errp) < 0) {
+ return NULL;
+ }
+
+ ret = g_base64_encode(data, datalen);
+ g_free(data);
+ return ret;
+}
+
+
+static const TypeInfo qcrypto_secret_info = {
+ .parent = TYPE_OBJECT,
+ .name = TYPE_QCRYPTO_SECRET,
+ .instance_size = sizeof(QCryptoSecret),
+ .instance_init = qcrypto_secret_init,
+ .instance_finalize = qcrypto_secret_finalize,
+ .class_size = sizeof(QCryptoSecretClass),
+ .class_init = qcrypto_secret_class_init,
+ .interfaces = (InterfaceInfo[]) {
+ { TYPE_USER_CREATABLE },
+ { }
+ }
+};
+
+
+static void
+qcrypto_secret_register_types(void)
+{
+ type_register_static(&qcrypto_secret_info);
+}
+
+
+type_init(qcrypto_secret_register_types);