Adding upstream version 2.10.0+dfsg.upstream/2.10.0+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 577 insertions, 0 deletions

diff --git a/drivers/auth/auth_mod.c b/drivers/auth/auth_mod.c
new file mode 100644
index 0000000..608866c
--- /dev/null
+++ b/drivers/auth/auth_mod.c
@@ -0,0 +1,577 @@
+/*
+ * Copyright (c) 2015-2023, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <platform_def.h>
+
+#include <common/debug.h>
+#include <common/tbbr/cot_def.h>
+#include <drivers/auth/auth_common.h>
+#include <drivers/auth/auth_mod.h>
+#include <drivers/auth/crypto_mod.h>
+#include <drivers/auth/img_parser_mod.h>
+#include <drivers/fwu/fwu.h>
+#include <lib/fconf/fconf_tbbr_getter.h>
+#include <plat/common/platform.h>
+
+#include <tools_share/zero_oid.h>
+
+/* ASN.1 tags */
+#define ASN1_INTEGER                 0x02
+
+#pragma weak plat_set_nv_ctr2
+
+static int cmp_auth_param_type_desc(const auth_param_type_desc_t *a,
+		const auth_param_type_desc_t *b)
+{
+	if ((a->type == b->type) && (a->cookie == b->cookie)) {
+		return 0;
+	}
+	return 1;
+}
+
+/*
+ * This function obtains the requested authentication parameter data from the
+ * information extracted from the parent image after its authentication.
+ */
+static int auth_get_param(const auth_param_type_desc_t *param_type_desc,
+			  const auth_img_desc_t *img_desc,
+			  void **param, unsigned int *len)
+{
+	int i;
+
+	if (img_desc->authenticated_data == NULL)
+		return 1;
+
+	for (i = 0 ; i < COT_MAX_VERIFIED_PARAMS ; i++) {
+		if (0 == cmp_auth_param_type_desc(param_type_desc,
+				img_desc->authenticated_data[i].type_desc)) {
+			*param = img_desc->authenticated_data[i].data.ptr;
+			*len = img_desc->authenticated_data[i].data.len;
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/*
+ * Authenticate an image by matching the data hash
+ *
+ * This function implements 'AUTH_METHOD_HASH'. To authenticate an image using
+ * this method, the image must contain:
+ *
+ *   - The data to calculate the hash from
+ *
+ * The parent image must contain:
+ *
+ *   - The hash to be matched with (including hash algorithm)
+ *
+ * For a successful authentication, both hashes must match. The function calls
+ * the crypto-module to check this matching.
+ *
+ * Parameters:
+ *   param: parameters to perform the hash authentication
+ *   img_desc: pointer to image descriptor so we can know the image type
+ *             and parent image
+ *   img: pointer to image in memory
+ *   img_len: length of image (in bytes)
+ *
+ * Return:
+ *   0 = success, Otherwise = error
+ */
+static int auth_hash(const auth_method_param_hash_t *param,
+		     const auth_img_desc_t *img_desc,
+		     void *img, unsigned int img_len)
+{
+	void *data_ptr, *hash_der_ptr;
+	unsigned int data_len, hash_der_len;
+	int rc;
+
+	/* Get the hash from the parent image. This hash will be DER encoded
+	 * and contain the hash algorithm */
+	rc = auth_get_param(param->hash, img_desc->parent,
+			&hash_der_ptr, &hash_der_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Get the data to be hashed from the current image */
+	rc = img_parser_get_auth_param(img_desc->img_type, param->data,
+			img, img_len, &data_ptr, &data_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Ask the crypto module to verify this hash */
+	rc = crypto_mod_verify_hash(data_ptr, data_len,
+				    hash_der_ptr, hash_der_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+/*
+ * Authenticate by digital signature
+ *
+ * This function implements 'AUTH_METHOD_SIG'. To authenticate an image using
+ * this method, the image must contain:
+ *
+ *   - Data to be signed
+ *   - Signature
+ *   - Signature algorithm
+ *
+ * We rely on the image parser module to extract this data from the image.
+ * The parent image must contain:
+ *
+ *   - Public key (or a hash of it)
+ *
+ * If the parent image contains only a hash of the key, we will try to obtain
+ * the public key from the image itself (i.e. self-signed certificates). In that
+ * case, the signature verification is considered just an integrity check and
+ * the authentication is established by calculating the hash of the key and
+ * comparing it with the hash obtained from the parent.
+ *
+ * If the image has no parent (NULL), it means it has to be authenticated using
+ * the ROTPK stored in the platform. Again, this ROTPK could be the key itself
+ * or a hash of it.
+ *
+ * Return: 0 = success, Otherwise = error
+ */
+static int auth_signature(const auth_method_param_sig_t *param,
+			  const auth_img_desc_t *img_desc,
+			  void *img, unsigned int img_len)
+{
+	void *data_ptr, *pk_ptr, *cnv_pk_ptr, *pk_plat_ptr, *sig_ptr, *sig_alg_ptr, *pk_oid;
+	unsigned int data_len, pk_len, cnv_pk_len, pk_plat_len, sig_len, sig_alg_len;
+	unsigned int flags = 0;
+	int rc;
+
+	/* Get the data to be signed from current image */
+	rc = img_parser_get_auth_param(img_desc->img_type, param->data,
+			img, img_len, &data_ptr, &data_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Get the signature from current image */
+	rc = img_parser_get_auth_param(img_desc->img_type, param->sig,
+			img, img_len, &sig_ptr, &sig_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Get the signature algorithm from current image */
+	rc = img_parser_get_auth_param(img_desc->img_type, param->alg,
+			img, img_len, &sig_alg_ptr, &sig_alg_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Get the public key from the parent. If there is no parent (NULL),
+	 * the certificate has been signed with the ROTPK, so we have to get
+	 * the PK from the platform */
+	if (img_desc->parent != NULL) {
+		rc = auth_get_param(param->pk, img_desc->parent,
+				&pk_ptr, &pk_len);
+		if (rc != 0) {
+			VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+				__func__, __LINE__, rc);
+			return rc;
+		}
+	} else {
+		/*
+		 * Root certificates are signed with the ROTPK, so we have to
+		 * get it from the platform.
+		 */
+		rc = plat_get_rotpk_info(param->pk->cookie, &pk_plat_ptr,
+					 &pk_plat_len, &flags);
+		if (rc != 0) {
+			VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+				__func__, __LINE__, rc);
+			return rc;
+		}
+
+		assert(is_rotpk_flags_valid(flags));
+
+		/* Also retrieve the key from the image. */
+		rc = img_parser_get_auth_param(img_desc->img_type,
+					       param->pk, img, img_len,
+					       &pk_ptr, &pk_len);
+		if (rc != 0) {
+			VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+				__func__, __LINE__, rc);
+			return rc;
+		}
+
+		/*
+		 * Validate the certificate's key against the platform ROTPK.
+		 *
+		 * Platform may store key in one of the following way -
+		 * 1. Hash of ROTPK
+		 * 2. Hash if prefixed, suffixed or modified ROTPK
+		 * 3. Full ROTPK
+		 */
+		if ((flags & ROTPK_NOT_DEPLOYED) != 0U) {
+			NOTICE("ROTPK is not deployed on platform. "
+				"Skipping ROTPK verification.\n");
+		} else if ((flags & ROTPK_IS_HASH) != 0U) {
+			/*
+			 * platform may store the hash of a prefixed,
+			 * suffixed or modified pk
+			 */
+			rc = crypto_mod_convert_pk(pk_ptr, pk_len, &cnv_pk_ptr, &cnv_pk_len);
+			if (rc != 0) {
+				VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+					__func__, __LINE__, rc);
+				return rc;
+			}
+
+			/*
+			 * The hash of the certificate's public key must match
+			 * the hash of the ROTPK.
+			 */
+			rc = crypto_mod_verify_hash(cnv_pk_ptr, cnv_pk_len,
+						    pk_plat_ptr, pk_plat_len);
+			if (rc != 0) {
+				VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+					__func__, __LINE__, rc);
+				return rc;
+			}
+		} else {
+			/* Platform supports full ROTPK */
+			if ((pk_len != pk_plat_len) ||
+			    (memcmp(pk_plat_ptr, pk_ptr, pk_len) != 0)) {
+				ERROR("plat and cert ROTPK len mismatch\n");
+				return -1;
+			}
+		}
+
+		/*
+		 * Set Zero-OID for ROTPK(subject key) as a the certificate
+		 * does not hold Key-OID information for ROTPK.
+		 */
+		if (param->pk->cookie != NULL) {
+			pk_oid = param->pk->cookie;
+		} else {
+			pk_oid = ZERO_OID;
+		}
+
+		/*
+		 * Public key is verified at this stage, notify platform
+		 * to measure and publish it.
+		 */
+		rc = plat_mboot_measure_key(pk_oid, pk_ptr, pk_len);
+		if (rc != 0) {
+			VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+				__func__, __LINE__, rc);
+		}
+	}
+
+	/* Ask the crypto module to verify the signature */
+	rc = crypto_mod_verify_signature(data_ptr, data_len,
+					 sig_ptr, sig_len,
+					 sig_alg_ptr, sig_alg_len,
+					 pk_ptr, pk_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+/*
+ * Authenticate by Non-Volatile counter
+ *
+ * To protect the system against rollback, the platform includes a non-volatile
+ * counter whose value can only be increased. All certificates include a counter
+ * value that should not be lower than the value stored in the platform. If the
+ * value is larger, the counter in the platform must be updated to the new value
+ * (provided it has been authenticated).
+ *
+ * Return: 0 = success, Otherwise = error
+ * Returns additionally,
+ * cert_nv_ctr -> NV counter value present in the certificate
+ * need_nv_ctr_upgrade = 0 -> platform NV counter upgrade is not needed
+ * need_nv_ctr_upgrade = 1 -> platform NV counter upgrade is needed
+ */
+static int auth_nvctr(const auth_method_param_nv_ctr_t *param,
+		      const auth_img_desc_t *img_desc,
+		      void *img, unsigned int img_len,
+		      unsigned int *cert_nv_ctr,
+		      bool *need_nv_ctr_upgrade)
+{
+	unsigned char *p;
+	void *data_ptr = NULL;
+	unsigned int data_len, len, i;
+	unsigned int plat_nv_ctr;
+	int rc;
+	bool is_trial_run = false;
+
+	/* Get the counter value from current image. The AM expects the IPM
+	 * to return the counter value as a DER encoded integer */
+	rc = img_parser_get_auth_param(img_desc->img_type, param->cert_nv_ctr,
+				       img, img_len, &data_ptr, &data_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Parse the DER encoded integer */
+	assert(data_ptr);
+	p = (unsigned char *)data_ptr;
+
+	/*
+	 * Integers must be at least 3 bytes: 1 for tag, 1 for length, and 1
+	 * for value.  The first byte (tag) must be ASN1_INTEGER.
+	 */
+	if ((data_len < 3) || (*p != ASN1_INTEGER)) {
+		/* Invalid ASN.1 integer */
+		return 1;
+	}
+	p++;
+
+	/*
+	 * NV-counters are unsigned integers up to 31 bits.  Trailing
+	 * padding is not allowed.
+	 */
+	len = (unsigned int)*p;
+	if ((len > 4) || (data_len - 2 != len)) {
+		return 1;
+	}
+	p++;
+
+	/* Check the number is not negative */
+	if (*p & 0x80) {
+		return 1;
+	}
+
+	/* Convert to unsigned int. This code is for a little-endian CPU */
+	*cert_nv_ctr = 0;
+	for (i = 0; i < len; i++) {
+		*cert_nv_ctr = (*cert_nv_ctr << 8) | *p++;
+	}
+
+	/* Get the counter from the platform */
+	rc = plat_get_nv_ctr(param->plat_nv_ctr->cookie, &plat_nv_ctr);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	if (*cert_nv_ctr < plat_nv_ctr) {
+		/* Invalid NV-counter */
+		return 1;
+	} else if (*cert_nv_ctr > plat_nv_ctr) {
+#if PSA_FWU_SUPPORT && IMAGE_BL2
+		is_trial_run = fwu_is_trial_run_state();
+#endif /* PSA_FWU_SUPPORT && IMAGE_BL2 */
+		*need_nv_ctr_upgrade = !is_trial_run;
+	}
+
+	return 0;
+}
+
+int plat_set_nv_ctr2(void *cookie, const auth_img_desc_t *img_desc __unused,
+		unsigned int nv_ctr)
+{
+	return plat_set_nv_ctr(cookie, nv_ctr);
+}
+
+/*
+ * Return the parent id in the output parameter '*parent_id'
+ *
+ * Return value:
+ *   0 = Image has parent, 1 = Image has no parent or parent is authenticated
+ */
+int auth_mod_get_parent_id(unsigned int img_id, unsigned int *parent_id)
+{
+	const auth_img_desc_t *img_desc = NULL;
+
+	assert(parent_id != NULL);
+	/* Get the image descriptor */
+	img_desc = FCONF_GET_PROPERTY(tbbr, cot, img_id);
+
+	/* Check if the image has no parent (ROT) */
+	if (img_desc->parent == NULL) {
+		*parent_id = 0;
+		return 1;
+	}
+
+	/* Check if the parent has already been authenticated */
+	if (auth_img_flags[img_desc->parent->img_id] & IMG_FLAG_AUTHENTICATED) {
+		*parent_id = 0;
+		return 1;
+	}
+
+	*parent_id = img_desc->parent->img_id;
+	return 0;
+}
+
+/*
+ * Initialize the different modules in the authentication framework
+ */
+void auth_mod_init(void)
+{
+	/* Check we have a valid CoT registered */
+	assert(cot_desc_ptr != NULL);
+
+	/* Image parser module */
+	img_parser_init();
+}
+
+/*
+ * Authenticate a certificate/image
+ *
+ * Return: 0 = success, Otherwise = error
+ */
+int auth_mod_verify_img(unsigned int img_id,
+			void *img_ptr,
+			unsigned int img_len)
+{
+	const auth_img_desc_t *img_desc = NULL;
+	const auth_param_type_desc_t *type_desc = NULL;
+	const auth_method_desc_t *auth_method = NULL;
+	void *param_ptr;
+	unsigned int param_len;
+	int rc, i;
+	unsigned int cert_nv_ctr = 0;
+	bool need_nv_ctr_upgrade = false;
+	bool sig_auth_done = false;
+	const auth_method_param_nv_ctr_t *nv_ctr_param = NULL;
+
+	/* Get the image descriptor from the chain of trust */
+	img_desc = FCONF_GET_PROPERTY(tbbr, cot, img_id);
+
+	/* Ask the parser to check the image integrity */
+	rc = img_parser_check_integrity(img_desc->img_type, img_ptr, img_len);
+	if (rc != 0) {
+		VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+			__func__, __LINE__, rc);
+		return rc;
+	}
+
+	/* Authenticate the image using the methods indicated in the image
+	 * descriptor. */
+	if (img_desc->img_auth_methods == NULL)
+		return 1;
+	for (i = 0 ; i < AUTH_METHOD_NUM ; i++) {
+		auth_method = &img_desc->img_auth_methods[i];
+		switch (auth_method->type) {
+		case AUTH_METHOD_NONE:
+			rc = 0;
+			break;
+		case AUTH_METHOD_HASH:
+			rc = auth_hash(&auth_method->param.hash,
+					img_desc, img_ptr, img_len);
+			break;
+		case AUTH_METHOD_SIG:
+			rc = auth_signature(&auth_method->param.sig,
+					img_desc, img_ptr, img_len);
+			sig_auth_done = true;
+			break;
+		case AUTH_METHOD_NV_CTR:
+			nv_ctr_param = &auth_method->param.nv_ctr;
+			rc = auth_nvctr(nv_ctr_param,
+					img_desc, img_ptr, img_len,
+					&cert_nv_ctr, &need_nv_ctr_upgrade);
+			break;
+		default:
+			/* Unknown authentication method */
+			rc = 1;
+			break;
+		}
+		if (rc != 0) {
+			VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+				__func__, __LINE__, rc);
+			return rc;
+		}
+	}
+
+	/*
+	 * Do platform NV counter upgrade only if the certificate gets
+	 * authenticated, and platform NV-counter upgrade is needed.
+	 */
+	if (need_nv_ctr_upgrade && sig_auth_done) {
+		rc = plat_set_nv_ctr2(nv_ctr_param->plat_nv_ctr->cookie,
+				      img_desc, cert_nv_ctr);
+		if (rc != 0) {
+			VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+				__func__, __LINE__, rc);
+			return rc;
+		}
+	}
+
+	/* Extract the parameters indicated in the image descriptor to
+	 * authenticate the children images. */
+	if (img_desc->authenticated_data != NULL) {
+		for (i = 0 ; i < COT_MAX_VERIFIED_PARAMS ; i++) {
+			if (img_desc->authenticated_data[i].type_desc == NULL) {
+				continue;
+			}
+
+			/* Get the parameter from the image parser module */
+			rc = img_parser_get_auth_param(img_desc->img_type,
+					img_desc->authenticated_data[i].type_desc,
+					img_ptr, img_len, &param_ptr, &param_len);
+			if (rc != 0) {
+				VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+					__func__, __LINE__, rc);
+				return rc;
+			}
+
+			/* Check parameter size */
+			if (param_len > img_desc->authenticated_data[i].data.len) {
+				return 1;
+			}
+
+			/* Copy the parameter for later use */
+			memcpy((void *)img_desc->authenticated_data[i].data.ptr,
+					(void *)param_ptr, param_len);
+
+			/*
+			 * If this is a public key then measure and publicise
+			 * it.
+			 */
+			type_desc = img_desc->authenticated_data[i].type_desc;
+			if (type_desc->type == AUTH_PARAM_PUB_KEY) {
+				rc = plat_mboot_measure_key(type_desc->cookie,
+							    param_ptr,
+							    param_len);
+				if (rc != 0) {
+					VERBOSE("[TBB] %s():%d failed with error code %d.\n",
+						__func__, __LINE__, rc);
+				}
+			}
+		}
+	}
+
+	/* Mark image as authenticated */
+	auth_img_flags[img_desc->img_id] |= IMG_FLAG_AUTHENTICATED;
+
+	return 0;
+}