diff --git a/include/drivers/auth/auth_mod.h b/include/drivers/auth/auth_mod.h index 3965b58..d1fd52c 100644 --- a/include/drivers/auth/auth_mod.h +++ b/include/drivers/auth/auth_mod.h @@ -21,7 +21,18 @@ */ #define IMG_FLAG_AUTHENTICATED (1 << 0) - +#if COT_DESC_IN_DTB && !IMAGE_BL1 +/* + * Authentication image descriptor + */ +typedef struct auth_img_desc_s { + unsigned int img_id; + img_type_t img_type; + const struct auth_img_desc_s *parent; + auth_method_desc_t *img_auth_methods; + auth_param_desc_t *authenticated_data; +} auth_img_desc_t; +#else /* * Authentication image descriptor */ @@ -32,6 +43,7 @@ const auth_method_desc_t *const img_auth_methods; const auth_param_desc_t *const authenticated_data; } auth_img_desc_t; +#endif /* COT_DESC_IN_DTB && !IMAGE_BL1 */ /* Public functions */ void auth_mod_init(void); diff --git a/include/tools_share/tbbr_oid.h b/include/tools_share/tbbr_oid.h index 37d87d3..c789f79 100644 --- a/include/tools_share/tbbr_oid.h +++ b/include/tools_share/tbbr_oid.h @@ -7,6 +7,8 @@ #ifndef TBBR_OID_H #define TBBR_OID_H +#define MAX_OID_NAME_LEN 30 + /* * The following is a list of OID values defined and reserved by ARM, which * are used to define the extension fields of the certificate structure, as diff --git a/lib/fconf/fconf_cot_getter.c b/lib/fconf/fconf_cot_getter.c new file mode 100644 index 0000000..adfa534 --- /dev/null +++ b/lib/fconf/fconf_cot_getter.c @@ -0,0 +1,497 @@ +/* + * Copyright (c) 2020, Arm Limited. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include +#include + +#include +#include +#include +#include +#include +#include + +#include + +/* static structures used during authentication process */ +static auth_param_type_desc_t sig = AUTH_PARAM_TYPE_DESC( + AUTH_PARAM_SIG, 0); +static auth_param_type_desc_t sig_alg = AUTH_PARAM_TYPE_DESC( + AUTH_PARAM_SIG_ALG, 0); +static auth_param_type_desc_t raw_data = AUTH_PARAM_TYPE_DESC( + AUTH_PARAM_RAW_DATA, 0); + +/* pointers to an array of CoT descriptors */ +static const auth_img_desc_t *cot_desc[MAX_NUMBER_IDS]; +/* array of CoT descriptors */ +static auth_img_desc_t auth_img_descs[MAX_NUMBER_IDS]; + +/* array of authentication methods structures */ +static auth_method_desc_t auth_methods[MAX_NUMBER_IDS * AUTH_METHOD_NUM]; +static OBJECT_POOL_ARRAY(auth_methods_pool, auth_methods); + +/* array of authentication params structures */ +static auth_param_desc_t auth_params[MAX_NUMBER_IDS * COT_MAX_VERIFIED_PARAMS]; +static OBJECT_POOL_ARRAY(auth_params_pool, auth_params); + +/* array of authentication param type structures */ +static auth_param_type_desc_t auth_param_type_descs[MAX_NUMBER_IDS]; +static OBJECT_POOL_ARRAY(auth_param_type_descs_pool, auth_param_type_descs); + +/* + * array of OIDs + * Object IDs are used to search hash, pk, counter values in certificate. + * As per binding we have below 2 combinations: + * 1. Certificates are validated using nv-cntr and pk + * 2. Raw images are authenticated using hash + * Hence in worst case, there are maximum 2 OIDs per image/certificate + */ +static unsigned char oids[(MAX_NUMBER_IDS * 2)][MAX_OID_NAME_LEN]; +static OBJECT_POOL_ARRAY(oid_pool, oids); + +/* An array of auth buffer which holds hashes and pk + * ToDo: Size decided with the current number of images and + * certificates which are available in CoT. Size of these buffers bound to + * increase in the future on the addition of images/certificates. + */ +static unsigned char hash_auth_bufs[20][HASH_DER_LEN]; +static OBJECT_POOL_ARRAY(hash_auth_buf_pool, hash_auth_bufs); +static unsigned char pk_auth_bufs[12][PK_DER_LEN]; +static OBJECT_POOL_ARRAY(pk_auth_buf_pool, pk_auth_bufs); + +/******************************************************************************* + * update_parent_auth_data() - Update authentication data structure + * @auth_desc[in]: Pointer to the auth image descriptor + * @type_desc[in]: Pointer to authentication parameter + * @auth_buf_size[in]: Buffer size to hold pk or hash + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int update_parent_auth_data(const auth_img_desc_t *auth_desc, + auth_param_type_desc_t *type_desc, + unsigned int auth_buf_size) +{ + unsigned int i; + auth_param_desc_t *auth_data = &auth_desc->authenticated_data[0]; + unsigned char *auth_buf; + + for (i = 0U; i < COT_MAX_VERIFIED_PARAMS; i++) { + if (auth_data[i].type_desc == type_desc) { + return 0; + } + if (auth_data[i].type_desc == NULL) { + break; + } + } + + if (auth_buf_size == HASH_DER_LEN) { + auth_buf = pool_alloc(&hash_auth_buf_pool); + } else if (auth_buf_size == PK_DER_LEN) { + auth_buf = pool_alloc(&pk_auth_buf_pool); + } else { + return -1; + } + + if (i < COT_MAX_VERIFIED_PARAMS) { + auth_data[i].type_desc = type_desc; + auth_data[i].data.ptr = auth_buf; + auth_data[i].data.len = auth_buf_size; + } else { + ERROR("Out of authentication data array\n"); + return -1; + } + + return 0; +} + +/******************************************************************************* + * get_auth_param_type_desc() - Get pointer of authentication parameter + * @img_id[in]: Image Id + * @type_desc[out]: Pointer to authentication parameter + * @buf_size[out]: Buffer size which hold hash/pk + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int get_auth_param_type_desc(unsigned int img_id, + auth_param_type_desc_t **type_desc, + unsigned int *buf_size) +{ + auth_method_desc_t *img_auth_method = NULL; + img_type_t type = auth_img_descs[img_id].img_type; + + if (type == IMG_CERT) { + img_auth_method = + &auth_img_descs[img_id].img_auth_methods[AUTH_METHOD_SIG]; + *type_desc = img_auth_method->param.sig.pk; + *buf_size = PK_DER_LEN; + } else if (type == IMG_RAW) { + img_auth_method = + &auth_img_descs[img_id].img_auth_methods[AUTH_METHOD_HASH]; + *type_desc = img_auth_method->param.hash.hash; + *buf_size = HASH_DER_LEN; + } else { + return -1; + } + + return 0; +} + +/******************************************************************************* + * set_auth_method() - Update global auth image descriptors with authentication + * method data + * @auth_method_type[in]: Type of authentication method + * @oid[in]: Object Idetifier for pk/hash search + * @auth_method[in]: Pointer to authentication method to set + ******************************************************************************/ +static void set_auth_method(auth_method_type_t auth_method_type, char *oid, + auth_method_desc_t *auth_method) +{ + auth_param_type_t auth_param_type = AUTH_PARAM_NONE; + auth_param_type_desc_t *auth_param_type_desc; + + assert(auth_method != NULL); + + auth_param_type_desc = pool_alloc(&auth_param_type_descs_pool); + auth_method->type = auth_method_type; + + if (auth_method_type == AUTH_METHOD_SIG) { + auth_param_type = AUTH_PARAM_PUB_KEY; + auth_method->param.sig.sig = &sig; + auth_method->param.sig.alg = &sig_alg; + auth_method->param.sig.data = &raw_data; + auth_method->param.sig.pk = auth_param_type_desc; + } else if (auth_method_type == AUTH_METHOD_HASH) { + auth_param_type = AUTH_PARAM_HASH; + auth_method->param.hash.data = &raw_data; + auth_method->param.hash.hash = auth_param_type_desc; + } else if (auth_method_type == AUTH_METHOD_NV_CTR) { + auth_param_type = AUTH_PARAM_NV_CTR; + auth_method->param.nv_ctr.cert_nv_ctr = auth_param_type_desc; + auth_method->param.nv_ctr.plat_nv_ctr = auth_param_type_desc; + } + + auth_param_type_desc->type = auth_param_type; + auth_param_type_desc->cookie = (void *)oid; +} + +/******************************************************************************* + * get_oid() - get object identifier from device tree + * @dtb[in]: Pointer to the device tree blob in memory + * @node[in]: Offset of the node + * @prop[in]: Property to read from the given node + * @oid[out]: Object Indentifier of key/hash/nv-counter in certificate + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int get_oid(const void *dtb, int node, const char *prop, char **oid) +{ + uint32_t phandle; + int rc; + + rc = fdt_read_uint32(dtb, node, prop, &phandle); + if (rc < 0) { + return rc; + } + + node = fdt_node_offset_by_phandle(dtb, phandle); + if (node < 0) { + return node; + } + + *oid = pool_alloc(&oid_pool); + rc = fdtw_read_string(dtb, node, "oid", *oid, MAX_OID_NAME_LEN); + + return rc; +} + +/******************************************************************************* + * populate_and_set_auth_methods() - Populate auth method parameters from + * device tree and set authentication method + * structure. + * @dtb[in]: Pointer to the device tree blob in memory + * @node[in]: Offset of the node + * @img_id[in]: Image identifier + * @type[in]: Type of image + * @root_certificate[in]:Root certificate (authenticated by ROTPK) + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int populate_and_set_auth_methods(const void *dtb, int node, + unsigned int img_id, img_type_t type, + bool root_certificate) +{ + auth_method_type_t auth_method_type = AUTH_METHOD_NONE; + int rc; + char *oid = NULL; + + auth_method_desc_t *auth_method = pool_alloc_n(&auth_methods_pool, + AUTH_METHOD_NUM); + + /* + * This is as per binding document where certificates are + * verified by signature and images are verified by hash. + */ + if (type == IMG_CERT) { + if (root_certificate) { + oid = NULL; + } else { + rc = get_oid(dtb, node, "signing-key", &oid); + if (rc < 0) { + ERROR("FCONF: Can't read %s property\n", + "signing-key"); + return rc; + } + } + auth_method_type = AUTH_METHOD_SIG; + } else if (type == IMG_RAW) { + rc = get_oid(dtb, node, "hash", &oid); + if (rc < 0) { + ERROR("FCONF: Can't read %s property\n", + "hash"); + return rc; + } + auth_method_type = AUTH_METHOD_HASH; + } else { + return -1; + } + + set_auth_method(auth_method_type, oid, + &auth_method[auth_method_type]); + + /* Retrieve the optional property */ + rc = get_oid(dtb, node, "antirollback-counter", &oid); + if (rc == 0) { + auth_method_type = AUTH_METHOD_NV_CTR; + set_auth_method(auth_method_type, oid, + &auth_method[auth_method_type]); + } + + auth_img_descs[img_id].img_auth_methods = &auth_method[0]; + + return 0; +} + +/******************************************************************************* + * get_parent_img_id() - Get parent image id for given child node + * @dtb[in]: Pointer to the device tree blob in memory + * @node[in]: Offset of the child node + * @parent_img_id[out]: Image id of parent + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int get_parent_img_id(const void *dtb, int node, + unsigned int *parent_img_id) +{ + uint32_t phandle; + int err; + + err = fdt_read_uint32(dtb, node, "parent", &phandle); + if (err < 0) { + ERROR("FCONF: Could not read %s property in node\n", + "parent"); + return err; + } + + node = fdt_node_offset_by_phandle(dtb, phandle); + if (node < 0) { + ERROR("FCONF: Failed to locate node using its phandle\n"); + return node; + } + + err = fdt_read_uint32(dtb, node, "image-id", parent_img_id); + if (err < 0) { + ERROR("FCONF: Could not read %s property in node\n", + "image-id"); + } + + return err; +} + +/******************************************************************************* + * set_desc_data() - Update data in descriptor's structure + * @dtb[in]: Pointer to the device tree blob in memory + * @node[in]: Offset of the node + * @type[in]: Type of image (RAW/CERT) + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int set_desc_data(const void *dtb, int node, img_type_t type) +{ + int rc; + bool root_certificate = false; + unsigned int img_id, parent_img_id; + + rc = fdt_read_uint32(dtb, node, "image-id", &img_id); + if (rc < 0) { + ERROR("FCONF: Can't find property %s in node\n", + "image-id"); + return rc; + } + + if (fdt_getprop(dtb, node, "root-certificate", + NULL) != NULL) { + root_certificate = true; + } + + if (!root_certificate) { + rc = get_parent_img_id(dtb, node, &parent_img_id); + if (rc < 0) { + return rc; + } + auth_img_descs[img_id].parent = &auth_img_descs[parent_img_id]; + } + + auth_img_descs[img_id].img_id = img_id; + auth_img_descs[img_id].img_type = type; + + rc = populate_and_set_auth_methods(dtb, node, img_id, type, + root_certificate); + if (rc < 0) { + return rc; + } + + if (type == IMG_CERT) { + auth_param_desc_t *auth_param = + pool_alloc_n(&auth_params_pool, + COT_MAX_VERIFIED_PARAMS); + auth_img_descs[img_id].authenticated_data = &auth_param[0]; + } + + cot_desc[img_id] = &auth_img_descs[img_id]; + + return rc; +} + +/******************************************************************************* + * populate_manifest_descs() - Populate CoT descriptors and update global + * certificate structures + * @dtb[in]: Pointer to the device tree blob in memory + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int populate_manifest_descs(const void *dtb) +{ + int node, child; + int rc; + + /* + * Assert the node offset points to "arm, cert-descs" + * compatible property + */ + const char *compatible_str = "arm, cert-descs"; + + node = fdt_node_offset_by_compatible(dtb, -1, compatible_str); + if (node < 0) { + ERROR("FCONF: Can't find %s compatible in node\n", + compatible_str); + return node; + } + + fdt_for_each_subnode(child, dtb, node) { + rc = set_desc_data(dtb, child, IMG_CERT); + if (rc < 0) { + return rc; + } + } + + return 0; +} + +/******************************************************************************* + * populate_image_descs() - Populate CoT descriptors and update global + * image descriptor structures. + * @dtb[in]: Pointer to the device tree blob in memory + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int populate_image_descs(const void *dtb) +{ + int node, child; + int rc; + + /* + * Assert the node offset points to "arm, img-descs" + * compatible property + */ + const char *compatible_str = "arm, img-descs"; + + node = fdt_node_offset_by_compatible(dtb, -1, compatible_str); + if (node < 0) { + ERROR("FCONF: Can't find %s compatible in node\n", + compatible_str); + return node; + } + + fdt_for_each_subnode(child, dtb, node) { + rc = set_desc_data(dtb, child, IMG_RAW); + if (rc < 0) { + return rc; + } + } + + return 0; +} + +/******************************************************************************* + * fconf_populate_cot_descs() - Populate CoT descriptors and update global + * structures + * @config[in]: Pointer to the device tree blob in memory + * + * Return 0 on success or an error value otherwise. + ******************************************************************************/ +static int fconf_populate_cot_descs(uintptr_t config) +{ + auth_param_type_desc_t *type_desc = NULL; + unsigned int auth_buf_size = 0U; + int rc; + + /* As libfdt uses void *, we can't avoid this cast */ + const void *dtb = (void *)config; + + /* populate manifest descs information */ + rc = populate_manifest_descs(dtb); + if (rc < 0) { + ERROR("FCONF: population of %s descs failed %d\n", + "manifest", rc); + return rc; + } + + /* populate image descs information */ + rc = populate_image_descs(dtb); + if (rc < 0) { + ERROR("FCONF: population of %s descs failed %d\n", + "images", rc); + return rc; + } + + /* update parent's authentication data */ + for (unsigned int i = 0U; i < MAX_NUMBER_IDS; i++) { + if (auth_img_descs[i].parent != NULL) { + rc = get_auth_param_type_desc(i, + &type_desc, + &auth_buf_size); + if (rc < 0) { + ERROR("FCONF: failed to get auth data %d\n", + rc); + return rc; + } + + rc = update_parent_auth_data(auth_img_descs[i].parent, + type_desc, + auth_buf_size); + if (rc < 0) { + ERROR("FCONF: auth data update failed %d\n", + rc); + return rc; + } + } + } + + return rc; +} + +FCONF_REGISTER_POPULATOR(TB_FW, cot_desc, fconf_populate_cot_descs); +REGISTER_COT(cot_desc); diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk index 96ab2d3..bbcc954 100644 --- a/plat/arm/common/arm_common.mk +++ b/plat/arm/common/arm_common.mk @@ -297,9 +297,14 @@ # Include the selected chain of trust sources. ifeq (${COT},tbbr) - AUTH_SOURCES += drivers/auth/tbbr/tbbr_cot_common.c - BL1_SOURCES += drivers/auth/tbbr/tbbr_cot_bl1.c - BL2_SOURCES += drivers/auth/tbbr/tbbr_cot_bl2.c + BL1_SOURCES += drivers/auth/tbbr/tbbr_cot_common.c \ + drivers/auth/tbbr/tbbr_cot_bl1.c + ifneq (${COT_DESC_IN_DTB},0) + BL2_SOURCES += lib/fconf/fconf_cot_getter.c + else + BL2_SOURCES += drivers/auth/tbbr/tbbr_cot_common.c \ + drivers/auth/tbbr/tbbr_cot_bl2.c + endif else ifeq (${COT},dualroot) AUTH_SOURCES += drivers/auth/dualroot/cot.c else