[PATCH v3] Add support for OpenSSL Provider API
Mattijs Korpershoek
mkorpershoek at kernel.org
Thu Jan 29 21:08:17 CET 2026
Hi Eddie,
Thank you for the patch.
On Tue, Jan 20, 2026 at 09:45, Eddie Kovsky <ekovsky at redhat.com> wrote:
> 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.
>
> 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 at redhat.com>
> Date: Fri Sep 20 19:52:48 2024 +0300
>
> sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3
>
> The changes have been tested with the FIT signature verification vboot
> tests on Fedora 42 and Debian 13. All 30 tests pass with both the legacy
> Engine library installed and with the Provider API.
>
> Signed-off-by: Eddie Kovsky <ekovsky at redhat.com>
As a follow-up, can we look into reverting/removing
commit 3a8b919932fd ("tools: avoid OpenSSL deprecation warnings") ?
This looks much better than v2 in my opinion.
Some additional comments below:
> ---
> 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/
> ---
> lib/aes/aes-encrypt.c | 4 +-
> lib/rsa/rsa-sign.c | 95 ++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 97 insertions(+), 2 deletions(-)
>
> diff --git a/lib/aes/aes-encrypt.c b/lib/aes/aes-encrypt.c
> index 90e1407b4f09..4fc4ce232478 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..31269db65950 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 main.c:%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)
> {
> @@ -98,6 +138,7 @@ err_cert:
> * @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)
> {
> @@ -157,6 +198,7 @@ static int rsa_engine_get_pub_key(const char *keydir, const char *name,
>
> return 0;
> }
> +#endif
>
> /**
> * rsa_get_pub_key() - read a public key
> @@ -170,8 +212,10 @@ static int rsa_engine_get_pub_key(const char *keydir, const char *name,
With this change, the ENGINE pointer might be NULL (or undefined).
Can we please update the documentation comment to reflect this?
For example, we could reword as:
* @engine Engine to use or NULL when using pcks11 provider
> 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);
> }
Actually, looking even closer at this function, it's seems to be called
only once.
Why can't we drop this function alltogether and call
rsa_engine_get_pub_key() / rsa_pem_get_pub_key() directly in
rsa_add_verify_data() ?
Reason I'm asking: in rsa_add_verify_data(), ENGINE *e is not used when
we use PROVIDER. It seems weird (and error prone) to pass a NULL pointer
to a function that does not need that argument
>
> @@ -207,6 +251,37 @@ 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);
> @@ -214,6 +289,7 @@ static int rsa_pem_get_priv_key(const char *keydir, const char *name,
> }
> fclose(f);
>
> +#endif
> return 0;
This block should be
fclose(f);
+#endif
return 0;
(not having a blank line between the fclose and the #endif)
> }
>
> @@ -226,6 +302,7 @@ 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)
> @@ -293,6 +370,7 @@ static int rsa_engine_get_priv_key(const char *keydir, const char *name,
>
> return 0;
> }
> +#endif
>
> /**
> * rsa_get_priv_key() - read a private key
> @@ -306,9 +384,11 @@ static int rsa_engine_get_priv_key(const char *keydir, const char *name,
> 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);
Same remark as for rsa_engine_get_pub_key. Can't we drop this static
function? It's only called once.
Maybe do a cleanup patch first, that gets rid of the static functions
and then do the provider support in a second patch of the same series?
I think it will reduce the amount of #ifdefs, which seems a good
argument.
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