cert_create: Use RSASSA-PSS signature scheme for certificates
This patch modifies the `cert_create` tool to use RSASSA-PSS scheme for
signing the certificates. This is compliant with RSA PKCS_2_1 standard as
mandated by TBBR.
Note that the certificates generated by using cert_create tool after this
patch can be authenticated during TBB only if the corresponding mbedtls
driver in ARM Trusted Firmware has the corresponding support.
Change-Id: If224f41c76b3c4765ae2af5259e67f73602818a4
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/tools/cert_create/src/cert.c b/tools/cert_create/src/cert.c
index 80ccfe9..9775664 100644
--- a/tools/cert_create/src/cert.c
+++ b/tools/cert_create/src/cert.c
@@ -10,6 +10,7 @@
#include <openssl/conf.h>
#include <openssl/err.h>
+#include <openssl/opensslv.h>
#include <openssl/pem.h>
#include <openssl/sha.h>
#include <openssl/x509v3.h>
@@ -27,6 +28,7 @@
#include "sha.h"
#define SERIAL_RAND_BITS 64
+#define RSA_SALT_LEN 32
int rand_serial(BIGNUM *b, ASN1_INTEGER *ai)
{
@@ -77,7 +79,6 @@
return 1;
}
-
int cert_new(cert_t *cert, int days, int ca, STACK_OF(X509_EXTENSION) * sk)
{
EVP_PKEY *pkey = keys[cert->key].key;
@@ -88,7 +89,9 @@
X509_EXTENSION *ex;
X509_NAME *name;
ASN1_INTEGER *sno;
- int i, num;
+ int i, num, rc = 0;
+ EVP_MD_CTX mdCtx;
+ EVP_PKEY_CTX *pKeyCtx = NULL;
/* Create the certificate structure */
x = X509_new();
@@ -108,6 +111,27 @@
issuer = x;
}
+ EVP_MD_CTX_init(&mdCtx);
+ if (!EVP_DigestSignInit(&mdCtx, &pKeyCtx, EVP_sha256(), NULL, ikey)) {
+ ERR_print_errors_fp(stdout);
+ goto END;
+ }
+
+ if (!EVP_PKEY_CTX_set_rsa_padding(pKeyCtx, RSA_PKCS1_PSS_PADDING)) {
+ ERR_print_errors_fp(stdout);
+ goto END;
+ }
+
+ if (!EVP_PKEY_CTX_set_rsa_pss_saltlen(pKeyCtx, RSA_SALT_LEN)) {
+ ERR_print_errors_fp(stdout);
+ goto END;
+ }
+
+ if (!EVP_PKEY_CTX_set_rsa_mgf1_md(pKeyCtx, EVP_sha256())) {
+ ERR_print_errors_fp(stdout);
+ goto END;
+ }
+
/* x509.v3 */
X509_set_version(x, 2);
@@ -152,14 +176,18 @@
}
}
- /* Sign the certificate with the issuer key */
- if (!X509_sign(x, ikey, EVP_sha256())) {
+ if (!X509_sign_ctx(x, &mdCtx)) {
ERR_print_errors_fp(stdout);
- return 0;
+ goto END;
}
+ /* X509 certificate signed successfully */
+ rc = 1;
cert->x = x;
- return 1;
+
+END:
+ EVP_MD_CTX_cleanup(&mdCtx);
+ return rc;
}
int cert_init(void)