Merge remote-tracking branch 'remotes/berrange/tags/pull-qcrypto-secrets-base-2015-12-18-1' into staging

Merge QCryptoSecret object support

# gpg: Signature made Fri 18 Dec 2015 16:51:21 GMT using RSA key ID 15104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"

* remotes/berrange/tags/pull-qcrypto-secrets-base-2015-12-18-1:
  crypto: add support for loading encrypted x509 keys
  crypto: add QCryptoSecret object class for password/key handling
  qga: convert to use error checked base64 decode
  qemu-char: convert to use error checked base64 decode
  util: add base64 decoding function

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 562 insertions, 0 deletions

diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index b2a0e0b..a3135f1 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -7,6 +7,7 @@ crypto-obj-y += tlscreds.o
 crypto-obj-y += tlscredsanon.o
 crypto-obj-y += tlscredsx509.o
 crypto-obj-y += tlssession.o
+crypto-obj-y += secret.o
 
 # Let the userspace emulators avoid linking gnutls/etc
 crypto-aes-obj-y = aes.o
diff --git a/crypto/secret.c b/crypto/secret.c
new file mode 100644
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);
diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c
index 26f18cb..d58fdea 100644
--- a/crypto/tlscredsx509.c
+++ b/crypto/tlscredsx509.c
@@ -20,6 +20,7 @@
 
 #include "crypto/tlscredsx509.h"
 #include "crypto/tlscredspriv.h"
+#include "crypto/secret.h"
 #include "qom/object_interfaces.h"
 #include "trace.h"
 
@@ -607,9 +608,30 @@ qcrypto_tls_creds_x509_load(QCryptoTLSCredsX509 *creds,
     }
 
     if (cert != NULL && key != NULL) {
+#if GNUTLS_VERSION_NUMBER >= 0x030111
+        char *password = NULL;
+        if (creds->passwordid) {
+            password = qcrypto_secret_lookup_as_utf8(creds->passwordid,
+                                                     errp);
+            if (!password) {
+                goto cleanup;
+            }
+        }
+        ret = gnutls_certificate_set_x509_key_file2(creds->data,
+                                                    cert, key,
+                                                    GNUTLS_X509_FMT_PEM,
+                                                    password,
+                                                    0);
+        g_free(password);
+#else /* GNUTLS_VERSION_NUMBER < 0x030111 */
+        if (creds->passwordid) {
+            error_setg(errp, "PKCS8 decryption requires GNUTLS >= 3.1.11");
+            goto cleanup;
+        }
         ret = gnutls_certificate_set_x509_key_file(creds->data,
                                                    cert, key,
                                                    GNUTLS_X509_FMT_PEM);
+#endif /* GNUTLS_VERSION_NUMBER < 0x030111 */
         if (ret < 0) {
             error_setg(errp, "Cannot load certificate '%s' & key '%s': %s",
                        cert, key, gnutls_strerror(ret));
@@ -737,6 +759,27 @@ qcrypto_tls_creds_x509_prop_set_sanity(Object *obj,
 }
 
 
+static void
+qcrypto_tls_creds_x509_prop_set_passwordid(Object *obj,
+                                           const char *value,
+                                           Error **errp G_GNUC_UNUSED)
+{
+    QCryptoTLSCredsX509 *creds = QCRYPTO_TLS_CREDS_X509(obj);
+
+    creds->passwordid = g_strdup(value);
+}
+
+
+static char *
+qcrypto_tls_creds_x509_prop_get_passwordid(Object *obj,
+                                           Error **errp G_GNUC_UNUSED)
+{
+    QCryptoTLSCredsX509 *creds = QCRYPTO_TLS_CREDS_X509(obj);
+
+    return g_strdup(creds->passwordid);
+}
+
+
 static bool
 qcrypto_tls_creds_x509_prop_get_sanity(Object *obj,
                                        Error **errp G_GNUC_UNUSED)
@@ -769,6 +812,10 @@ qcrypto_tls_creds_x509_init(Object *obj)
                              qcrypto_tls_creds_x509_prop_get_sanity,
                              qcrypto_tls_creds_x509_prop_set_sanity,
                              NULL);
+    object_property_add_str(obj, "passwordid",
+                            qcrypto_tls_creds_x509_prop_get_passwordid,
+                            qcrypto_tls_creds_x509_prop_set_passwordid,
+                            NULL);
 }
 
 
@@ -777,6 +824,7 @@ qcrypto_tls_creds_x509_finalize(Object *obj)
 {
     QCryptoTLSCredsX509 *creds = QCRYPTO_TLS_CREDS_X509(obj);
 
+    g_free(creds->passwordid);
     qcrypto_tls_creds_x509_unload(creds);
 }