[PATCH v5 0/3] Add support for OpenSSL Provider API

[PATCH v5 0/3] Add support for OpenSSL Provider API

[Eddie Kovsky]

The Engine API has been deprecated since the release of OpenSSL 3.0. End
users have been advised to migrate to the new Provider interface.
Several distributions have already removed support for engines, which is
preventing U-Boot from being compiled in those environments.

This series adds support for the OpenSSL Provider API while continuing
to support the existing Engine API on distros shipping older releases of
OpenSSL. Build dependencies for local development and CI are also
updated, while the final patch adds support for using hardware tokens
with the Provider API.

The changes have been tested with the FIT signature verification vboot
tests on Fedora 44, Debian 13, and RHEL 8 with OpenSSL 1.1.1. All 37
tests pass with both the legacy Engine library installed and with the
Provider API.

Signed-off-by: Eddie Kovsky <ekovsky@redhat.com>
---
Changes in v5:
- Fix Tested-by trailers
- Change error string in drain_openssl_errors()
- Additional testing on RHEL 8 with openssl 1.1.1
- Tested hardware token signing path with SoftHSM
v4: https://lore.kernel.org/u-boot/20260429180247.83091-1-ekovsky@redhat.com/

Changes in v4:
- Add comment that @engine pointer is null when using pkcs11 provider
- Remove extra line break
- Add pkcs11-provider package to build dependencies
v3: https://lore.kernel.org/u-boot/20260120164524.253188-1-ekovsky@redhat.com/

Changes in v3:
- Removed Kconfig option
- Changed macro symbol from CONFIG_OPENSSL_NO_DEPRECATED to
    USE_PKCS11_PROVIDER or USE_PKCS11_ENGINE
v2: https://lore.kernel.org/u-boot/20251027195834.71109-1-ekovsky@redhat.com/

Changes in v2:
- Remove default for new Kconfig option
- Use #ifdef instead of IS_ENABLED macro
- Remove comment after #endif
- Remove unrelated checkpatch cleanup of 'sslErr' variable name
v1: https://lore.kernel.org/u-boot/20251017171329.255689-1-ekovsky@redhat.com/
---

Eddie Kovsky (3):
  Add support for OpenSSL Provider API
  Add pkcs11-provider package to build dependencies
  rsa: load a pkcs11 token key through OSSL_STORE in the provider path

 doc/build/gcc.rst       |   4 +-
 lib/aes/aes-encrypt.c   |   4 +-
 lib/rsa/rsa-sign.c      | 194 ++++++++++++++++++++++++++++++++++++++--
 tools/docker/Dockerfile |   1 +
 4 files changed, 195 insertions(+), 8 deletions(-)

-- 
2.56.0

[PATCH v5 1/3] Add support for OpenSSL Provider API

[Eddie Kovsky]

Add support for the Provider API while continuing to support the existing
Engine API on distros shipping older releases of OpenSSL.

This is based on similar work contributed by Jan Stancek updating Linux
to use the Provider interface.

    commit 558bdc45dfb2669e1741384a0c80be9c82fa052c
    Author: Jan Stancek <jstancek@redhat.com>
    Date:   Fri Sep 20 19:52:48 2024 +0300

        sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3

Tested-by: Enric Balletbo i Serra <eballetb@redhat.com>
Tested-by: Mark Kettenis <mark.kettenis@xs4all.nl>
Signed-off-by: Eddie Kovsky <ekovsky@redhat.com>
---
 lib/aes/aes-encrypt.c |   4 +-
 lib/rsa/rsa-sign.c    | 102 +++++++++++++++++++++++++++++++++++++++---
 2 files changed, 100 insertions(+), 6 deletions(-)

diff --git a/lib/aes/aes-encrypt.c b/lib/aes/aes-encrypt.c
index def33a3b3248..0cb2221df800 100644
--- a/lib/aes/aes-encrypt.c
+++ b/lib/aes/aes-encrypt.c
@@ -16,7 +16,9 @@
 #include <openssl/err.h>
 #include <openssl/ssl.h>
 #include <openssl/evp.h>
-#include <openssl/engine.h>
+#if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0)
+# include <openssl/engine.h>
+#endif
 #include <uboot_aes.h>
 
 #if OPENSSL_VERSION_NUMBER >= 0x10000000L
diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c
index 0e38c9e802fd..361ed0647bc6 100644
--- a/lib/rsa/rsa-sign.c
+++ b/lib/rsa/rsa-sign.c
@@ -19,7 +19,47 @@
 #include <openssl/err.h>
 #include <openssl/ssl.h>
 #include <openssl/evp.h>
-#include <openssl/engine.h>
+#if OPENSSL_VERSION_MAJOR >= 3
+# define USE_PKCS11_PROVIDER
+# include <err.h>
+# include <openssl/provider.h>
+# include <openssl/store.h>
+#else
+# if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0)
+#  define USE_PKCS11_ENGINE
+#  include <openssl/engine.h>
+# endif
+#endif
+
+#ifdef USE_PKCS11_PROVIDER
+#define ERR(cond, fmt, ...)				\
+	do {						\
+		bool __cond = (cond);			\
+		drain_openssl_errors(__LINE__, 0);	\
+		if (__cond) {				\
+			errx(1, fmt, ## __VA_ARGS__);	\
+		}					\
+	} while (0)
+
+static void drain_openssl_errors(int l, int silent)
+{
+	const char *file;
+	char buf[120];
+	int e, line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	if (!silent)
+		fprintf(stderr, "At line:%d:\n", l);
+
+	while ((e = ERR_peek_error_line(&file, &line))) {
+		ERR_error_string(e, buf);
+		if (!silent)
+			fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
+		ERR_get_error();
+	}
+}
+#endif
 
 static int rsa_err(const char *msg)
 {
@@ -94,10 +134,11 @@ err_cert:
  *
  * @keydir:	Key prefix
  * @name	Name of key
- * @engine	Engine to use
+ * @engine	Engine to use or NULL when using pkcs11 provider
  * @evpp	Returns EVP_PKEY object, or NULL on failure
  * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
  */
+#ifdef USE_PKCS11_ENGINE
 static int rsa_engine_get_pub_key(const char *keydir, const char *name,
 				  ENGINE *engine, EVP_PKEY **evpp)
 {
@@ -157,21 +198,24 @@ static int rsa_engine_get_pub_key(const char *keydir, const char *name,
 
 	return 0;
 }
+#endif
 
 /**
  * rsa_get_pub_key() - read a public key
  *
  * @keydir:	Directory containing the key (PEM file) or key prefix (engine)
  * @name	Name of key file (will have a .crt extension)
- * @engine	Engine to use
+ * @engine	Engine to use or NULL when using pkcs11 provider
  * @evpp	Returns EVP_PKEY object, or NULL on failure
  * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
  */
 static int rsa_get_pub_key(const char *keydir, const char *name,
 			   ENGINE *engine, EVP_PKEY **evpp)
 {
+#ifdef USE_PKCS11_ENGINE
 	if (engine)
 		return rsa_engine_get_pub_key(keydir, name, engine, evpp);
+#endif
 	return rsa_pem_get_pub_key(keydir, name, evpp);
 }
 
@@ -207,13 +251,44 @@ static int rsa_pem_get_priv_key(const char *keydir, const char *name,
 		return -ENOENT;
 	}
 
+#ifdef USE_PKCS11_PROVIDER
+	EVP_PKEY *private_key = NULL;
+	OSSL_STORE_CTX *store;
+
+	if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true))
+		ERR(1, "OSSL_PROVIDER_try_load(pkcs11)");
+	if (!OSSL_PROVIDER_try_load(NULL, "default", true))
+		ERR(1, "OSSL_PROVIDER_try_load(default)");
+
+	store = OSSL_STORE_open(path, NULL, NULL, NULL, NULL);
+	ERR(!store, "OSSL_STORE_open");
+
+	while (!OSSL_STORE_eof(store)) {
+		OSSL_STORE_INFO *info = OSSL_STORE_load(store);
+
+		if (!info) {
+			drain_openssl_errors(__LINE__, 0);
+			continue;
+		}
+		if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_PKEY) {
+			private_key = OSSL_STORE_INFO_get1_PKEY(info);
+			ERR(!private_key, "OSSL_STORE_INFO_get1_PKEY");
+		}
+		OSSL_STORE_INFO_free(info);
+		if (private_key)
+			break;
+	}
+	OSSL_STORE_close(store);
+
+	*evpp = private_key;
+#else
 	if (!PEM_read_PrivateKey(f, evpp, NULL, path)) {
 		rsa_err("Failure reading private key");
 		fclose(f);
 		return -EPROTO;
 	}
 	fclose(f);
-
+#endif
 	return 0;
 }
 
@@ -226,6 +301,7 @@ static int rsa_pem_get_priv_key(const char *keydir, const char *name,
  * @evpp	Returns EVP_PKEY object, or NULL on failure
  * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
  */
+#ifdef USE_PKCS11_ENGINE
 static int rsa_engine_get_priv_key(const char *keydir, const char *name,
 				   const char *keyfile,
 				   ENGINE *engine, EVP_PKEY **evpp)
@@ -293,22 +369,25 @@ static int rsa_engine_get_priv_key(const char *keydir, const char *name,
 
 	return 0;
 }
+#endif
 
 /**
  * rsa_get_priv_key() - read a private key
  *
  * @keydir:	Directory containing the key (PEM file) or key prefix (engine)
  * @name	Name of key
- * @engine	Engine to use for signing
+ * @engine	Engine to use or NULL when using pkcs11 provider
  * @evpp	Returns EVP_PKEY object, or NULL on failure
  * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
  */
 static int rsa_get_priv_key(const char *keydir, const char *name,
 			    const char *keyfile, ENGINE *engine, EVP_PKEY **evpp)
 {
+#ifdef USE_PKCS11_ENGINE
 	if (engine)
 		return rsa_engine_get_priv_key(keydir, name, keyfile, engine,
 					       evpp);
+#endif
 	return rsa_pem_get_priv_key(keydir, name, keyfile, evpp);
 }
 
@@ -325,6 +404,7 @@ static int rsa_init(void)
 	return 0;
 }
 
+#ifdef USE_PKCS11_ENGINE
 static int rsa_engine_init(const char *engine_id, ENGINE **pe)
 {
 	const char *key_pass;
@@ -380,6 +460,7 @@ static void rsa_engine_remove(ENGINE *e)
 		ENGINE_free(e);
 	}
 }
+#endif
 
 static int rsa_sign_with_key(EVP_PKEY *pkey, struct padding_algo *padding_algo,
 			     struct checksum_algo *checksum_algo,
@@ -480,11 +561,13 @@ int rsa_sign(struct image_sign_info *info,
 	if (ret)
 		return ret;
 
+#ifdef USE_PKCS11_ENGINE
 	if (info->engine_id) {
 		ret = rsa_engine_init(info->engine_id, &e);
 		if (ret)
 			return ret;
 	}
+#endif
 
 	ret = rsa_get_priv_key(info->keydir, info->keyname, info->keyfile,
 			       e, &pkey);
@@ -496,16 +579,21 @@ int rsa_sign(struct image_sign_info *info,
 		goto err_sign;
 
 	EVP_PKEY_free(pkey);
+
+#ifdef USE_PKCS11_ENGINE
 	if (info->engine_id)
 		rsa_engine_remove(e);
+#endif
 
 	return ret;
 
 err_sign:
 	EVP_PKEY_free(pkey);
 err_priv:
+#ifdef USE_PKCS11_ENGINE
 	if (info->engine_id)
 		rsa_engine_remove(e);
+#endif
 	return ret;
 }
 
@@ -645,11 +733,13 @@ int rsa_add_verify_data(struct image_sign_info *info, void *keydest)
 	ENGINE *e = NULL;
 
 	debug("%s: Getting verification data\n", __func__);
+#ifdef USE_PKCS11_ENGINE
 	if (info->engine_id) {
 		ret = rsa_engine_init(info->engine_id, &e);
 		if (ret)
 			return ret;
 	}
+#endif
 	ret = rsa_get_pub_key(info->keydir, info->keyname, e, &pkey);
 	if (ret)
 		goto err_get_pub_key;
@@ -726,8 +816,10 @@ done:
 err_get_params:
 	EVP_PKEY_free(pkey);
 err_get_pub_key:
+#ifdef USE_PKCS11_ENGINE
 	if (info->engine_id)
 		rsa_engine_remove(e);
+#endif
 
 	if (ret)
 		return ret;
-- 
2.56.0

[PATCH v5 2/3] Add pkcs11-provider package to build dependencies

[Eddie Kovsky]

This package is needed to use PKCS11 with OpenSSL >= 3.0.

Signed-off-by: Eddie Kovsky <ekovsky@redhat.com>
---
 doc/build/gcc.rst       | 4 ++--
 tools/docker/Dockerfile | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/doc/build/gcc.rst b/doc/build/gcc.rst
index 1fef718ceecb..29a6a632e7e3 100644
--- a/doc/build/gcc.rst
+++ b/doc/build/gcc.rst
@@ -25,8 +25,8 @@ Depending on the build targets further packages maybe needed
 
     sudo apt-get install bc bison build-essential coccinelle \
       device-tree-compiler dfu-util efitools flex gdisk graphviz imagemagick \
-      libgnutls28-dev libguestfs-tools libncurses-dev \
-      libpython3-dev libsdl2-dev libssl-dev lz4 lzma lzma-alone openssl \
+      libgnutls28-dev libguestfs-tools libncurses-dev libpython3-dev \
+      libsdl2-dev libssl-dev lz4 lzma lzma-alone openssl pkcs11-provider \
       pkg-config python3 python3-asteval python3-coverage python3-filelock \
       python3-pkg-resources python3-pycryptodome python3-pyelftools \
       python3-pytest python3-pytest-xdist python3-sphinxcontrib.apidoc \
diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
index 187320c26d59..109d6503d8cd 100644
--- a/tools/docker/Dockerfile
+++ b/tools/docker/Dockerfile
@@ -122,6 +122,7 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
 	openssl \
 	picocom \
 	parted \
+	pkcs11-provider \
 	pkg-config \
 	python-is-python3 \
 	python3 \
-- 
2.56.0

[PATCH v5 3/3] rsa: load a pkcs11 token key through OSSL_STORE in the provider path

[Eddie Kovsky]

From: Johannes Schneider <johannes.schneider@leica-geosystems.com>

The OpenSSL Provider API support routes FIT signing-key loading through
OSSL_STORE on OpenSSL >= 3 (USE_PKCS11_PROVIDER), but only for key files:
rsa_pem_get_priv_key() fopen()s the path before OSSL_STORE_open(), so a pkcs11:
token URI fails with -ENOENT. The legacy engine path that handled tokens is
compiled out on OpenSSL >= 3, so FIT signing with a token key silently produces
an unsigned FIT (a configuration signature node with no value or
hashed-strings).

Load a pkcs11: key URI in the provider path directly through OSSL_STORE and the
pkcs11 provider: skip the fopen, append ";type=private" if absent. The PIN
travels in the URI (pin-value=); MKIMAGE_SIGN_PIN is unaffected.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Johannes Schneider <johannes.schneider@leica-geosystems.com>
Co-developed-by: Eddie Kovsky <ekovsky@redhat.com>
Signed-off-by: Eddie Kovsky <ekovsky@redhat.com>
---
 lib/rsa/rsa-sign.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c
index 361ed0647bc6..c39a2a11652f 100644
--- a/lib/rsa/rsa-sign.c
+++ b/lib/rsa/rsa-sign.c
@@ -92,6 +92,52 @@ static int rsa_pem_get_pub_key(const char *keydir, const char *name, EVP_PKEY **
 		return -EINVAL;
 
 	*evpp = NULL;
+#ifdef USE_PKCS11_PROVIDER
+	/*
+	 * A pkcs11: token URI is not a file: load it via OSSL_STORE + the pkcs11
+	 * provider instead of fopen (PIN in the URI, pin-value=).
+	 */
+	if (keydir && !strncmp(keydir, "pkcs11:", 7)) {
+		char uri[1200];
+		OSSL_STORE_CTX *p11_store;
+		EVP_PKEY *p11_key = NULL;
+
+		if (strstr(keydir, "type="))
+			snprintf(uri, sizeof(uri), "%s", keydir);
+		else
+			snprintf(uri, sizeof(uri), "%s;type=public", keydir);
+
+		if (!OSSL_PROVIDER_try_load(NULL, "default", true))
+			ERR(1, "OSSL_PROVIDER_try_load(default)");
+		if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true))
+			ERR(1, "OSSL_PROVIDER_try_load(pkcs11)");
+
+		p11_store = OSSL_STORE_open(uri, NULL, NULL, NULL, NULL);
+		ERR(!p11_store, "OSSL_STORE_open(%s)", uri);
+		while (!OSSL_STORE_eof(p11_store)) {
+			OSSL_STORE_INFO *info = OSSL_STORE_load(p11_store);
+
+			if (!info) {
+				if (OSSL_STORE_error(p11_store))
+					break;
+				continue;
+			}
+			if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_PUBKEY)
+				p11_key = OSSL_STORE_INFO_get1_PUBKEY(info);
+			OSSL_STORE_INFO_free(info);
+			if (p11_key)
+				break;
+		}
+		OSSL_STORE_close(p11_store);
+		if (!p11_key) {
+			fprintf(stderr, "No public key found at '%s'\n", uri);
+			return -EPROTO;
+		}
+		*evpp = p11_key;
+		return 0;
+	}
+
+#endif
 	snprintf(path, sizeof(path), "%s/%s.crt", keydir, name);
 	f = fopen(path, "r");
 	if (!f) {
@@ -237,6 +283,52 @@ static int rsa_pem_get_priv_key(const char *keydir, const char *name,
 		return -EINVAL;
 
 	*evpp = NULL;
+
+#ifdef USE_PKCS11_PROVIDER
+	/*
+	 * A pkcs11: token URI is not a file: load it via OSSL_STORE + the pkcs11
+	 * provider instead of fopen (PIN in the URI, pin-value=).
+	 */
+	if (keydir && !strncmp(keydir, "pkcs11:", 7)) {
+		char uri[1200];
+		OSSL_STORE_CTX *p11_store;
+		EVP_PKEY *p11_key = NULL;
+
+		if (strstr(keydir, "type="))
+			snprintf(uri, sizeof(uri), "%s", keydir);
+		else
+			snprintf(uri, sizeof(uri), "%s;type=private", keydir);
+
+		if (!OSSL_PROVIDER_try_load(NULL, "default", true))
+			ERR(1, "OSSL_PROVIDER_try_load(default)");
+		if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true))
+			ERR(1, "OSSL_PROVIDER_try_load(pkcs11)");
+
+		p11_store = OSSL_STORE_open(uri, NULL, NULL, NULL, NULL);
+		ERR(!p11_store, "OSSL_STORE_open(%s)", uri);
+		while (!OSSL_STORE_eof(p11_store)) {
+			OSSL_STORE_INFO *info = OSSL_STORE_load(p11_store);
+
+			if (!info) {
+				if (OSSL_STORE_error(p11_store))
+					break;
+				continue;
+			}
+			if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_PKEY)
+				p11_key = OSSL_STORE_INFO_get1_PKEY(info);
+			OSSL_STORE_INFO_free(info);
+			if (p11_key)
+				break;
+		}
+		OSSL_STORE_close(p11_store);
+		if (!p11_key) {
+			fprintf(stderr, "No private key found at '%s'\n", uri);
+			return -EPROTO;
+		}
+		*evpp = p11_key;
+		return 0;
+	}
+#endif
 	if (keydir && name)
 		snprintf(path, sizeof(path), "%s/%s.key", keydir, name);
 	else if (keyfile)
-- 
2.56.0