TBB: add tool to generate certificates
This patch adds a tool that generates all the necessary elements
to establish the chain of trust (CoT) between the images.
The tool reads the binary images and signing keys and outputs the
corresponding certificates that will be used by the target at run
time to verify the authenticity of the images.
Note: the platform port must provide the file platform_oid.h. This
file will define the OIDs of the x509 extensions that will be added
to the certificates in order to establish the CoT.
Change-Id: I2734d6808b964a2107ab3a4805110698066a04be
diff --git a/tools/cert_create/src/ext.c b/tools/cert_create/src/ext.c
new file mode 100644
index 0000000..31f84a8
--- /dev/null
+++ b/tools/cert_create/src/ext.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <openssl/err.h>
+#include <openssl/x509v3.h>
+#include "ext.h"
+
+DECLARE_ASN1_ITEM(ASN1_INTEGER)
+DECLARE_ASN1_ITEM(ASN1_OCTET_STRING)
+
+/*
+ * This function adds the TBB extensions to the internal extension list
+ * maintained by OpenSSL so they can be used later.
+ *
+ * It also initializes the methods to print the contents of the extension. If an
+ * alias is specified in the TBB extension, we reuse the methods of the alias.
+ * Otherwise, only methods for V_ASN1_INTEGER and V_ASN1_OCTET_STRING are
+ * provided. Any other type will be printed as a raw ascii string.
+ *
+ * Return: 0 = success, Otherwise: error
+ */
+int ext_init(ext_t *tbb_ext)
+{
+ ext_t *ext;
+ X509V3_EXT_METHOD *m;
+ int i = 0, nid, ret;
+
+ while ((ext = &tbb_ext[i++]) && ext->oid) {
+ nid = OBJ_create(ext->oid, ext->sn, ext->ln);
+ if (ext->alias) {
+ X509V3_EXT_add_alias(nid, ext->alias);
+ } else {
+ m = &ext->method;
+ memset(m, 0x0, sizeof(X509V3_EXT_METHOD));
+ switch (ext->type) {
+ case V_ASN1_INTEGER:
+ m->it = ASN1_ITEM_ref(ASN1_INTEGER);
+ m->i2s = (X509V3_EXT_I2S)i2s_ASN1_INTEGER;
+ m->s2i = (X509V3_EXT_S2I)s2i_ASN1_INTEGER;
+ break;
+ case V_ASN1_OCTET_STRING:
+ m->it = ASN1_ITEM_ref(ASN1_OCTET_STRING);
+ m->i2s = (X509V3_EXT_I2S)i2s_ASN1_OCTET_STRING;
+ m->s2i = (X509V3_EXT_S2I)s2i_ASN1_OCTET_STRING;
+ break;
+ default:
+ continue;
+ }
+ m->ext_nid = nid;
+ ret = X509V3_EXT_add(m);
+ if (!ret) {
+ ERR_print_errors_fp(stdout);
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+ * Create a new extension
+ *
+ * Extension ::= SEQUENCE {
+ * id OBJECT IDENTIFIER,
+ * critical BOOLEAN DEFAULT FALSE,
+ * value OCTET STRING }
+ *
+ * Parameters:
+ * pex: OpenSSL extension pointer (output parameter)
+ * nid: extension identifier
+ * crit: extension critical (EXT_NON_CRIT, EXT_CRIT)
+ * data: extension data. This data will be encapsulated in an Octet String
+ *
+ * Return: Extension address, NULL if error
+ */
+static
+X509_EXTENSION *ext_new(int nid, int crit, unsigned char *data, int len)
+{
+ X509_EXTENSION *ex;
+ ASN1_OCTET_STRING *ext_data;
+
+ /* Octet string containing the extension data */
+ ext_data = ASN1_OCTET_STRING_new();
+ ASN1_OCTET_STRING_set(ext_data, data, len);
+
+ /* Create the extension */
+ ex = X509_EXTENSION_create_by_NID(NULL, nid, crit, ext_data);
+
+ /* The extension makes a copy of the data, so we can free this object */
+ ASN1_OCTET_STRING_free(ext_data);
+
+ return ex;
+}
+
+/*
+ * Creates a x509v3 extension containing a hash encapsulated in an ASN1 Octet
+ * String
+ *
+ * Parameters:
+ * pex: OpenSSL extension pointer (output parameter)
+ * nid: extension identifier
+ * crit: extension critical (EXT_NON_CRIT, EXT_CRIT)
+ * buf: pointer to the buffer that contains the hash
+ * len: size of the hash in bytes
+ *
+ * Return: Extension address, NULL if error
+ */
+X509_EXTENSION *ext_new_hash(int nid, int crit, unsigned char *buf, size_t len)
+{
+ X509_EXTENSION *ex = NULL;
+ ASN1_OCTET_STRING *hash = NULL;
+ unsigned char *p = NULL;
+ int sz = -1;
+
+ /* Encode Hash */
+ hash = ASN1_OCTET_STRING_new();
+ ASN1_OCTET_STRING_set(hash, buf, len);
+ sz = i2d_ASN1_OCTET_STRING(hash, NULL);
+ i2d_ASN1_OCTET_STRING(hash, &p);
+
+ /* Create the extension */
+ ex = ext_new(nid, crit, p, sz);
+
+ /* Clean up */
+ OPENSSL_free(p);
+ ASN1_OCTET_STRING_free(hash);
+
+ return ex;
+}
+
+/*
+ * Creates a x509v3 extension containing a nvcounter encapsulated in an ASN1
+ * Integer
+ *
+ * Parameters:
+ * pex: OpenSSL extension pointer (output parameter)
+ * nid: extension identifier
+ * crit: extension critical (EXT_NON_CRIT, EXT_CRIT)
+ * value: nvcounter value
+ *
+ * Return: Extension address, NULL if error
+ */
+X509_EXTENSION *ext_new_nvcounter(int nid, int crit, int value)
+{
+ X509_EXTENSION *ex = NULL;
+ ASN1_INTEGER *counter = NULL;
+ unsigned char *p = NULL;
+ int sz = -1;
+
+ /* Encode counter */
+ counter = ASN1_INTEGER_new();
+ ASN1_INTEGER_set(counter, value);
+ sz = i2d_ASN1_INTEGER(counter, NULL);
+ i2d_ASN1_INTEGER(counter, &p);
+
+ /* Create the extension */
+ ex = ext_new(nid, crit, p, sz);
+
+ /* Free objects */
+ OPENSSL_free(p);
+ ASN1_INTEGER_free(counter);
+
+ return ex;
+}
+
+/*
+ * Creates a x509v3 extension containing a public key in DER format:
+ *
+ * SubjectPublicKeyInfo ::= SEQUENCE {
+ * algorithm AlgorithmIdentifier,
+ * subjectPublicKey BIT STRING }
+ *
+ * Parameters:
+ * pex: OpenSSL extension pointer (output parameter)
+ * nid: extension identifier
+ * crit: extension critical (EXT_NON_CRIT, EXT_CRIT)
+ * k: key
+ *
+ * Return: Extension address, NULL if error
+ */
+X509_EXTENSION *ext_new_key(int nid, int crit, EVP_PKEY *k)
+{
+ X509_EXTENSION *ex = NULL;
+ unsigned char *p = NULL;
+ int sz = -1;
+
+ /* Encode key */
+ BIO *mem = BIO_new(BIO_s_mem());
+ if (i2d_PUBKEY_bio(mem, k) <= 0) {
+ ERR_print_errors_fp(stderr);
+ return NULL;
+ }
+ p = (unsigned char *)OPENSSL_malloc(4096);
+ sz = BIO_read(mem, p, 4096);
+
+ /* Create the extension */
+ ex = ext_new(nid, crit, p, sz);
+
+ /* Clean up */
+ OPENSSL_free(p);
+
+ return ex;
+}