[Qemu-devel] [PATCH v4 2/4] hw/firmware: Add Edk2Crypto and edk2_add_host_crypto_policy()

[Philippe Mathieu-Daudé]

The Edk2Crypto object is used to hold configuration values specific
to EDK2.

The edk2_add_host_crypto_policy() function loads crypto policies
from the host, and register them as fw_cfg named file items.
So far only the 'https' policy is supported.

A usercase example is the 'HTTPS Boof' feature of OVMF [*].

Usage example:

  $ qemu-system-x86_64 \
      --object edk2_crypto,id=https,\
              ciphers=/etc/crypto-policies/back-ends/openssl.config,\
              cacerts=/etc/pki/ca-trust/extracted/edk2/cacerts.bin

(On Fedora these files are provided by the ca-certificates and
crypto-policies packages).

[*]: https://github.com/tianocore/edk2/blob/master/OvmfPkg/README

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
v3:
- '-object' -> '--object' in commit description (Eric)
- reworded the 'TODO: g_free' comment
v4:
- INTERFACE_CHECK -> OBJECT_CLASS_CHECK (Markus)
- path -> filename (Markus)
- dropped the 'TODO: g_free' comment (Markus)
- only allow 1 singleton (Markus)
---
 MAINTAINERS                             |   8 ++
 hw/Makefile.objs                        |   1 +
 hw/firmware/Makefile.objs               |   1 +
 hw/firmware/uefi_edk2_crypto_policies.c | 182 ++++++++++++++++++++++++
 include/hw/firmware/uefi_edk2.h         |  30 ++++
 5 files changed, 222 insertions(+)
 create mode 100644 hw/firmware/Makefile.objs
 create mode 100644 hw/firmware/uefi_edk2_crypto_policies.c
 create mode 100644 include/hw/firmware/uefi_edk2.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d326756079..1d6c30cab4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2207,6 +2207,14 @@ F: include/hw/i2c/smbus_master.h
 F: include/hw/i2c/smbus_slave.h
 F: include/hw/i2c/smbus_eeprom.h
 
+EDK2 Firmware
+M: Laszlo Ersek <address@hidden>
+M: Philippe Mathieu-Daudé <address@hidden>
+S: Maintained
+F: docs/interop/firmware.json
+F: hw/firmware/uefi_edk2_crypto_policies.c
+F: include/hw/firmware/uefi_edk2.h
+
 Usermode Emulation
 ------------------
 Overall
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 82aa7fab8e..2b075aa1e0 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -8,6 +8,7 @@ devices-dirs-$(CONFIG_SOFTMMU) += char/
 devices-dirs-$(CONFIG_SOFTMMU) += cpu/
 devices-dirs-$(CONFIG_SOFTMMU) += display/
 devices-dirs-$(CONFIG_SOFTMMU) += dma/
+devices-dirs-$(CONFIG_SOFTMMU) += firmware/
 devices-dirs-$(CONFIG_SOFTMMU) += gpio/
 devices-dirs-$(CONFIG_HYPERV) += hyperv/
 devices-dirs-$(CONFIG_I2C) += i2c/
diff --git a/hw/firmware/Makefile.objs b/hw/firmware/Makefile.objs
new file mode 100644
index 0000000000..ea1f6d44df
--- /dev/null
+++ b/hw/firmware/Makefile.objs
@@ -0,0 +1 @@
+common-obj-y += uefi_edk2_crypto_policies.o
diff --git a/hw/firmware/uefi_edk2_crypto_policies.c 
b/hw/firmware/uefi_edk2_crypto_policies.c
new file mode 100644
index 0000000000..c253115142
--- /dev/null
+++ b/hw/firmware/uefi_edk2_crypto_policies.c
@@ -0,0 +1,182 @@
+/*
+ * UEFI EDK2 Support
+ *
+ * Copyright (c) 2019 Red Hat Inc.
+ *
+ * Author:
+ *  Philippe Mathieu-Daudé <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qom/object_interfaces.h"
+#include "hw/firmware/uefi_edk2.h"
+
+
+#define TYPE_EDK2_CRYPTO "edk2_crypto"
+
+#define EDK2_CRYPTO_CLASS(klass) \
+     OBJECT_CLASS_CHECK(Edk2CryptoClass, (klass), \
+                        TYPE_EDK2_CRYPTO)
+#define EDK2_CRYPTO_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(Edk2CryptoClass, (obj), \
+                      TYPE_EDK2_CRYPTO)
+#define EDK2_CRYPTO(obj) \
+     OBJECT_CHECK(Edk2Crypto, (obj), \
+                  TYPE_EDK2_CRYPTO)
+
+typedef struct Edk2Crypto {
+    Object parent_obj;
+
+    bool initialized;
+
+    /*
+     * Path to the acceptable ciphersuites and the preferred order from
+     * the host-side crypto policy.
+     */
+    char *ciphers_filename;
+
+    /* Path to the trusted CA certificates configured on the host side. */
+    char *cacerts_filename;
+} Edk2Crypto;
+
+typedef struct Edk2CryptoClass {
+    ObjectClass parent_class;
+} Edk2CryptoClass;
+
+
+static void edk2_crypto_prop_set_ciphers(Object *obj, const char *value,
+                                         Error **errp G_GNUC_UNUSED)
+{
+    Edk2Crypto *s = EDK2_CRYPTO(obj);
+
+    g_free(s->ciphers_filename);
+    s->ciphers_filename = g_strdup(value);
+}
+
+static char *edk2_crypto_prop_get_ciphers(Object *obj,
+                                          Error **errp G_GNUC_UNUSED)
+{
+    Edk2Crypto *s = EDK2_CRYPTO(obj);
+
+    return g_strdup(s->ciphers_filename);
+}
+
+static void edk2_crypto_prop_set_cacerts(Object *obj, const char *value,
+                                         Error **errp G_GNUC_UNUSED)
+{
+    Edk2Crypto *s = EDK2_CRYPTO(obj);
+
+    g_free(s->cacerts_filename);
+    s->cacerts_filename = g_strdup(value);
+}
+
+static char *edk2_crypto_prop_get_cacerts(Object *obj,
+                                          Error **errp G_GNUC_UNUSED)
+{
+    Edk2Crypto *s = EDK2_CRYPTO(obj);
+
+    return g_strdup(s->cacerts_filename);
+}
+
+static void edk2_crypto_finalize(Object *obj)
+{
+    Edk2Crypto *s = EDK2_CRYPTO(obj);
+
+    g_free(s->ciphers_filename);
+    g_free(s->cacerts_filename);
+}
+
+static void edk2_crypto_class_init(ObjectClass *oc, void *data)
+{
+    object_class_property_add_str(oc, "ciphers",
+                                  edk2_crypto_prop_get_ciphers,
+                                  edk2_crypto_prop_set_ciphers,
+                                  NULL);
+    object_class_property_add_str(oc, "cacerts",
+                                  edk2_crypto_prop_get_cacerts,
+                                  edk2_crypto_prop_set_cacerts,
+                                  NULL);
+}
+
+static const TypeInfo edk2_crypto_info = {
+    .parent = TYPE_OBJECT,
+    .name = TYPE_EDK2_CRYPTO,
+    .instance_size = sizeof(Edk2Crypto),
+    .instance_finalize = edk2_crypto_finalize,
+    .class_size = sizeof(Edk2CryptoClass),
+    .class_init = edk2_crypto_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void edk2_crypto_register_types(void)
+{
+    type_register_static(&edk2_crypto_info);
+}
+
+type_init(edk2_crypto_register_types);
+
+static Edk2Crypto *edk2_crypto_by_id(const char *edk_crypto_id, Error **errp)
+{
+    Object *obj;
+    Object *container;
+
+    container = object_get_objects_root();
+    obj = object_resolve_path_component(container,
+                                        edk_crypto_id);
+    if (!obj) {
+        error_setg(errp, "Cannot find EDK2 crypto object ID %s",
+                   edk_crypto_id);
+        return NULL;
+    }
+
+    if (!object_dynamic_cast(obj, TYPE_EDK2_CRYPTO)) {
+        error_setg(errp, "Object '%s' is not a EDK2 crypto subclass",
+                   edk_crypto_id);
+        return NULL;
+    }
+
+    return EDK2_CRYPTO(obj);
+}
+
+bool edk2_add_host_crypto_policy(FWCfgState *fw_cfg, Error **errp)
+{
+    Edk2Crypto *s;
+    Error *local_err = NULL;
+
+    s = edk2_crypto_by_id("https", NULL);
+    if (!s) {
+        return true;
+    }
+    if (s->initialized) {
+        error_setg(errp, "EDK2 host crypto policy already initialized");
+        return false;
+    }
+    s->initialized = true;
+
+    if (s->ciphers_filename) {
+        if (!fw_cfg_add_file_from_host(fw_cfg, "etc/edk2/https/ciphers",
+                                       s->ciphers_filename, NULL,
+                                       &local_err)) {
+            goto report_error;
+        }
+    }
+    if (s->cacerts_filename) {
+        if (!fw_cfg_add_file_from_host(fw_cfg, "etc/edk2/https/cacerts",
+                                       s->cacerts_filename, NULL,
+                                       &local_err)) {
+            goto report_error;
+        }
+    }
+    return true;
+
+ report_error:
+    error_propagate_prepend(errp, local_err, "EDK2 host crypto policy: ");
+    return false;
+}
diff --git a/include/hw/firmware/uefi_edk2.h b/include/hw/firmware/uefi_edk2.h
new file mode 100644
index 0000000000..ff4a5439ce
--- /dev/null
+++ b/include/hw/firmware/uefi_edk2.h
@@ -0,0 +1,30 @@
+/*
+ * UEFI EDK2 Support
+ *
+ * Copyright (c) 2019 Red Hat Inc.
+ *
+ * Author:
+ *  Philippe Mathieu-Daudé <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_FIRMWARE_UEFI_EDK2_H
+#define HW_FIRMWARE_UEFI_EDK2_H
+
+#include "hw/nvram/fw_cfg.h"
+
+/**
+ * edk2_add_host_crypto_policy:
+ * @s: fw_cfg device being modified
+ * @errp: pointer to a NULL initialized error object
+ *
+ * Add a new named file containing the host crypto policy.
+ *
+ * Returns true on success, false on failure. In the latter case,
+ * an Error object is returned through @errp.
+ */
+bool edk2_add_host_crypto_policy(FWCfgState *fw_cfg, Error **errp);
+
+#endif /* HW_FIRMWARE_UEFI_EDK2_H */
-- 
2.20.1