Implement TCG DICE TCB Info X509 Extension

CMakeLists.txt

@@ -41,6 +41,7 @@ set(LIBNAT20_SOURCES
     # Add the core library source files here.
     src/core/asn1.c
     src/core/oid.c
+    src/core/x509_ext_tcg_dice_tcb_info.c
     src/core/x509.c
 )
 
@@ -50,13 +51,15 @@ set(LIBNAT20_PUB_HEADERS
     include/nat20/asn1.h
     include/nat20/crypto.h
     include/nat20/oid.h
+    include/nat20/x509_ext_tcg_dice_tcb_info.h
     include/nat20/x509.h
 )
 
 set(LIBNAT20_TEST_SOURCES
     # Add test source files here.
     src/core/test/test.cpp
     src/core/test/asn1.cpp
+    src/core/test/x509_ext_tcg_dice_tcb_info.cpp
 )
 
 set(LIBNAT20_DOC_PAGES

include/nat20/oid.h

@@ -37,7 +37,7 @@
  * @sa N20_ASN1_DEFINE_OID
  * @sa N20_ASN1_DECLARE_OID
  */
-#define N20_ASN1_MAX_OID_ELEMENTS 7
+#define N20_ASN1_MAX_OID_ELEMENTS 10
 
 /**
  * @brief Structure representing an object identifier.
@@ -129,6 +129,11 @@ N20_ASN1_DECLARE_OID(OID_EC_PUBLIC_KEY);
 N20_ASN1_DECLARE_OID(OID_SECP256R1);
 N20_ASN1_DECLARE_OID(OID_SECP384R1);
 
+N20_ASN1_DECLARE_OID(OID_SHA224);
+N20_ASN1_DECLARE_OID(OID_SHA256);
+N20_ASN1_DECLARE_OID(OID_SHA384);
+N20_ASN1_DECLARE_OID(OID_SHA512);
+
 N20_ASN1_DECLARE_OID(OID_ECDSA_WITH_SHA224);
 N20_ASN1_DECLARE_OID(OID_ECDSA_WITH_SHA256);
 N20_ASN1_DECLARE_OID(OID_ECDSA_WITH_SHA384);
@@ -144,4 +149,7 @@ N20_ASN1_DECLARE_OID(OID_COMMON_NAME);
 N20_ASN1_DECLARE_OID(OID_BASIC_CONSTRAINTS);
 N20_ASN1_DECLARE_OID(OID_KEY_USAGE);
 
+N20_ASN1_DECLARE_OID(OID_TCG_DICE_TCB_INFO);
+N20_ASN1_DECLARE_OID(OID_TCG_DICE_MULTI_TCB_INFO);
+
 /** @} */

include/nat20/x509_ext_tcg_dice_tcb_info.h

@@ -0,0 +1,326 @@
+/*
+ * Copyright 2025 Aurora Operations, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/** @file */
+
+#pragma once
+
+#include <nat20/asn1.h>
+#include <nat20/oid.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @defgroup n20_x509_ext_tcg_dice_tcb_info_operational_flags_macros TCG DICE TCB Info Operational
+ * Flags Macros.
+ *
+ * These macros set the corresponding flags in the operational flags (and mask)
+ * bit mask of @ref n20_x509_ext_tcg_dice_tcb_info_operational_flags_t.
+ * Each macro takes a pointer to an instance of
+ * @ref n20_x509_ext_tcg_dice_tcb_info_operational_flags_t as its argument.
+ *
+ * See TCG DICE Attestation Architecture Version 1.1, Section 6.1.1.1.
+ *
+ * # Example
+ *
+ * @code{.c}
+ * n20_x509_ext_tcg_dice_tcb_info_operational_flags_t operational_flags = {0};
+ * N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_SECURE(&operational_flags);
+ * @endcode
+ * @{
+ */
+
+/**
+ * @brief The target environment is not configured for normal operation.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_CONFIGURED(operational_flags) \
+    (operational_flags)->operational_flags_mask[0] |= 0x80
+/**
+ * @brief The target environment is not secure.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_SECURE(operational_flags) \
+    (operational_flags)->operational_flags_mask[0] |= 0x40
+/**
+ * @brief The target environment is recovering (e.g. from a failure).
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_RECOVERY(operational_flags) \
+    (operational_flags)->operational_flags_mask[0] |= 0x20
+/**
+ * @brief The target environment can be debuged.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_DEBUG(operational_flags) \
+    (operational_flags)->operational_flags_mask[0] |= 0x10
+/**
+ * @brief The target environment is vulnerable to replay attack.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_REPLAY_PROTECTED( \
+    operational_flags)                                                             \
+    (operational_flags)->operational_flags_mask[0] |= 0x08
+/**
+ * @brief The target environment is vulneerable to modification by unauthorized updates.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_INTEGRITY_PROTECTED( \
+    operational_flags)                                                                \
+    (operational_flags)->operational_flags_mask[0] |= 0x04
+/**
+ * @brief The target environment is not measured after being loaded into memory.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_RUNTIME_MEASURED( \
+    operational_flags)                                                             \
+    (operational_flags)->operational_flags_mask[0] |= 0x02
+/**
+ * @brief The target environment is mutable.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_IMMUTABLE(operational_flags) \
+    (operational_flags)->operational_flags_mask[0] |= 0x01
+/**
+ * @brief – The Target Environment measurements are not measurements of a Trusted Computing Base
+ * (TCB).
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_TCB(operational_flags) \
+    (operational_flags)->operational_flags_mask[1] |= 0x80
+/**
+ * @brief Used to force a fixed width of for the OperationalFlags (and OperationalFlagsMask) bit
+ * string.
+ */
+#define N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_FIXED_WIDTH(operational_flags) \
+    (operational_flags)->operational_flags_mask[3] |= 0x01
+/**
+ * @}
+ */
+
+/**
+ * @brief TCG DICE TCB Info Operational Flags.
+ *
+ * This type is used to populate the TCB Info Operational Flags and Operational Flags Mask
+ * ASN.1 bitstrings.
+ *
+ * Always zero initialize instances of this structure and
+ * set the flags using the @ref n20_x509_ext_tcg_dice_tcb_info_operational_flags_macros.
+ *
+ * # Example
+ *
+ * @code{.c}
+ * n20_x509_ext_tcg_dice_tcb_info_operational_flags_t operational_flags = {0};
+ * N20_X509_EXT_TCG_DICE_TCB_INFO_OPERATIONAL_FLAGS_SET_NOT_SECURE(&operational_flags);
+ * @endcode
+ *
+ * (See TCG DICE Attestation Architecture Version 1.1, Section 6.1.1.1.)
+ */
+typedef struct n20_x509_ext_tcg_dice_tcb_info_operational_flags_s {
+    /**
+     * @brief The operational flags mask.
+     *
+     * Use the @ref n20_x509_ext_tcg_dice_tcb_info_operational_flags_macros to set the individual
+     * bits of the operation flags mask. As described in
+     * @ref n20_x509_ext_tcg_dice_tcb_info_operational_flags_t, there is no need to access this
+     * field directly.
+     */
+    uint8_t operational_flags_mask[4];
+} n20_x509_ext_tcg_dice_tcb_info_operational_flags_t;
+
+/**
+ * @brief TCG DICE TCB FW ID.
+ *
+ * (See TCG DICE Attestation Architecture Version 1.1, Section 6.1.1.)
+ */
+typedef struct n20_x509_ext_tcg_dice_tcb_info_fwid_s {
+    /**
+     * @brief Hash algorithm OID of the algorithm used to generate the digest.
+     */
+    n20_asn1_object_identifier_t hash_algo;
+    /**
+     * @brief Digest of firmware, initialization values, or other settings of the Target
+     * Environment.
+     *
+     * If the digest buffer is NULL, no digest is added to the extension.
+     */
+    n20_asn1_slice_t digest;
+} n20_x509_ext_tcg_dice_tcb_info_fwid_t;
+
+/**
+ * @brief List of TCG DICE FWIDs.
+ *
+ * If the list is NULL, no FWIDs are inserted into the TCG DICE TCB Info extension.
+ */
+typedef struct n20_x509_ext_tcg_dice_tcb_info_fwid_list_s {
+    /**
+     * @brief List of FWIDs to include in the TCG DICE TCB Info extension.
+     */
+    n20_x509_ext_tcg_dice_tcb_info_fwid_t const *list;
+    /**
+     * @brief Number of FWIDs in the list.
+     */
+    size_t count;
+} n20_x509_ext_tcg_dice_tcb_info_fwid_list_t;
+
+/**
+ * @brief TCG DICE TCB Info X509 extension context.
+ *
+ * This is the context expected by
+ * @ref n20_x509_ext_tcg_dice_tcb_info_content.
+ * An instance of this object must be passed to the callback.
+ * This is typically done using @ref n20_x509_extension by
+ * initializing @ref n20_x509_extension_t.content_cb with
+ * @ref n20_x509_ext_tcg_dice_tcb_info_content and setting
+ * @ref n20_x509_extension_t.context to an instance of this
+ * struct.
+ *
+ * (See TCG DICE Attestation Architecture Version 1.1, Section 6.1.1.)
+ * @sa OID_TCG_DICE_TCB_INFO
+ */
+typedef struct n20_x509_ext_tcg_dice_tcb_info_s {
+    /**
+     * @brief The entity that created the measurement of the Target Environment.
+     *
+     * Must be a nul terminated UTF-8 encoded string.
+     *
+     * If NULL, vendor is not included in the generated extension.
+     */
+    char const *vendor;
+    /**
+     * @brief The product name associated with the measurement of the Target Environment.
+     *
+     * Must be a nul terminated UTF-8 encoded string.
+     *
+     * If NULL, model is not included in the generated extension.
+     */
+    char const *model;
+    /**
+     * @brief The revision string associated with the Target Environment.
+     *
+     * Must be a nul terminated UTF-8 encoded string.
+     *
+     * If NULL, version is not included in the generated extension.
+     */
+    char const *version;
+    /**
+     * @brief The security version number associated with the Target Environment.
+     */
+    int64_t svn;
+    /**
+     * @brief The DICE layer associated with this measurement of the Target Environment.
+     */
+    int64_t layer;
+    /**
+     * @brief A value that distinguishes different instances of the same type of Target Environment.
+     */
+    int64_t index;
+    /**
+     * @brief List of FWIDs to include in the extension.
+     *
+     * @sa n20_x509_ext_tcg_dice_tcb_info_fwid_list_t
+     */
+    n20_x509_ext_tcg_dice_tcb_info_fwid_list_t fwids;
+    /**
+     * @brief A list of flags that enumerate potentially simultaneous operational states of the
+     * Target Environment.
+     *
+     * @sa n20_x509_ext_tcg_dice_tcb_info_operational_flags_t
+     */
+    n20_x509_ext_tcg_dice_tcb_info_operational_flags_t flags;
+    /**
+     * @brief Used to commumicate which bits in @ref flags are meaningful.
+     *
+     * When a bit is set here, the bit at the corresponding position in @ref flags is meaninful to
+     * the verifier.
+     *
+     * @sa n20_x509_ext_tcg_dice_tcb_info_operational_flags_t
+     */
+    n20_x509_ext_tcg_dice_tcb_info_operational_flags_t flags_mask;
+    /**
+     * @brief Vendor supplied values that encode vendor, model, or device specific state.
+     *
+     * If vender_info.buffer is NULL vendor info is not included in the generated extension.
+     */
+    n20_asn1_slice_t vendor_info;
+    /**
+     * @brief A machine readable description of the measurement.
+     *
+     * If type.buffer is NULL, type is not included in the generated extension.
+     */
+    n20_asn1_slice_t type;
+} n20_x509_ext_tcg_dice_tcb_info_t;
+
+/**
+ * @brief Renders the value of a TCG DICE TCB Info X509 extension.
+ *
+ * The function expects a pointer to an instance of
+ * @ref n20_x509_ext_tcg_dice_tcb_info_t as @ref context argument.
+ *
+ * If @ref context is NULL, nothing is rendered, which would leave
+ * the resulting TCG DICE TCB Info extension malformed.
+ *
+ * This function is typically not used directly but instead
+ * passed to @ref n20_x509_extension by initializing an
+ * instance of @ref n20_x509_extensions_t
+ * (See @ref n20_x509_extension for an example).
+ */
+extern void n20_x509_ext_tcg_dice_tcb_info_content(n20_asn1_stream_t *const s, void *context);
+
+/**
+ * @brief TCG DICE Multi TCB Info X509 extension context.
+ *
+ * This is the context expected by
+ * @ref n20_x509_ext_tcg_dice_multi_tcb_info_content.
+ * An instance of this object must be passed to the callback.
+ * This is typically done using @ref n20_x509_extension by
+ * initializing @ref n20_x509_extension_t.content_cb with
+ * @ref n20_x509_ext_tcg_dice_multi_tcb_info_content and setting
+ * @ref n20_x509_extension_t.context to an instance of this
+ * struct.
+ *
+ * (See TCG DICE Attestation Architecture Version 1.1, Section 6.1.2.)
+ * @sa OID_TCG_DICE_MULTI_TCB_INFO
+ */
+typedef struct n20_x509_ext_tcg_dice_multi_tcb_info_s {
+    /**
+     * @brief List of TCB Info to include in the extension.
+     *
+     * If NULL, no list is rendered in the extension.
+     *
+     * @sa n20_x509_ext_tcg_dice_tcb_info_t
+     */
+    n20_x509_ext_tcg_dice_tcb_info_t const *list;
+    /**
+     * @brief Number of elements in the list.
+     */
+    size_t count;
+} n20_x509_ext_tcg_dice_multi_tcb_info_t;
+
+/**
+ * @brief Renders the value of a TCG DICE Multi TCB Info X509 extension.
+ *
+ * The function expects a pointer to an instance of
+ * @ref n20_x509_ext_tcg_dice_multi_tcb_info_t as @ref context argument.
+ *
+ * If @ref context is NULL, or the list is NULL or number of elements in the list is 0, nothing is
+ * rendered, which would leave the resulting TCG DICE Multi TCB Info extension malformed.
+ *
+ * This function is typically not used directly but instead
+ * passed to @ref n20_x509_extension by initializing an
+ * instance of @ref n20_x509_extensions_t
+ * (See @ref n20_x509_extension for an example).
+ */
+extern void n20_x509_ext_tcg_dice_multi_tcb_info_content(n20_asn1_stream_t *const s, void *context);
+
+#ifdef __cplusplus
+}
+#endif

src/core/oid.c

@@ -28,6 +28,11 @@ N20_ASN1_DEFINE_OID(OID_SECP256R1, 1, 2, 840, 10045, 3, 1, 7);
 /* Also known as NIST P-384 */
 N20_ASN1_DEFINE_OID(OID_SECP384R1, 1, 3, 132, 0, 34);
 
+N20_ASN1_DEFINE_OID(OID_SHA224, 2, 16, 840, 1, 101, 3, 4, 2, 4);
+N20_ASN1_DEFINE_OID(OID_SHA256, 2, 16, 840, 1, 101, 3, 4, 2, 1);
+N20_ASN1_DEFINE_OID(OID_SHA384, 2, 16, 840, 1, 101, 3, 4, 2, 2);
+N20_ASN1_DEFINE_OID(OID_SHA512, 2, 16, 840, 1, 101, 3, 4, 2, 3);
+
 N20_ASN1_DEFINE_OID(OID_ECDSA_WITH_SHA224, 1, 2, 840, 10045, 4, 3, 1);
 N20_ASN1_DEFINE_OID(OID_ECDSA_WITH_SHA256, 1, 2, 840, 10045, 4, 3, 2);
 N20_ASN1_DEFINE_OID(OID_ECDSA_WITH_SHA384, 1, 2, 840, 10045, 4, 3, 3);
@@ -42,3 +47,6 @@ N20_ASN1_DEFINE_OID(OID_COMMON_NAME, 2, 5, 4, 3);
 
 N20_ASN1_DEFINE_OID(OID_BASIC_CONSTRAINTS, 2, 5, 29, 19);
 N20_ASN1_DEFINE_OID(OID_KEY_USAGE, 2, 5, 29, 15);
+
+N20_ASN1_DEFINE_OID(OID_TCG_DICE_TCB_INFO, 2, 23, 133, 5, 4, 1);
+N20_ASN1_DEFINE_OID(OID_TCG_DICE_MULTI_TCB_INFO, 2, 23, 133, 5, 4, 5);