This allows OpenVPN to load non-default providers. This is mainly
useful for loading the legacy provider with --providers legacy default
Patch v4: use spaces to seperate providers, unload providers.
Patch v5: General cleanup, rename option to --providers, add
option to usage() and add an entry to Changes.rst
Signed-off-by: Arne Schwabe <a...@rfc2549.org>
---
Changes.rst | 7 +++++++
doc/man-sections/generic-options.rst | 12 +++++++++++
src/openvpn/crypto_backend.h | 15 ++++++++++++++
src/openvpn/crypto_mbedtls.c | 13 ++++++++++++
src/openvpn/crypto_mbedtls.h | 3 +++
src/openvpn/crypto_openssl.c | 30 ++++++++++++++++++++++++++++
src/openvpn/crypto_openssl.h | 9 +++++++++
src/openvpn/openvpn.c | 13 ++++++++++++
src/openvpn/options.c | 8 ++++++++
src/openvpn/options.h | 9 +++++++++
10 files changed, 119 insertions(+)
diff --git a/Changes.rst b/Changes.rst
index 6f04e59ac..0ce39a839 100644
--- a/Changes.rst
+++ b/Changes.rst
@@ -50,6 +50,13 @@ Compatibility mode (``--compat-mode``)
with older peers. The options ``--compat-mode`` allows UIs to provide users
with an easy way to still connect to older servers.
+OpenSSL 3.0 support
+ OpenSSL 3.0 has been added. Most of OpenSSL 3.0 changes are not user
visible but
+ improve general compatibility with OpenSSL 3.0. ``--tls-cert-profile
insecure``
+ has been added to allow selecting the lowest OpenSSL security level (not
+ recommended, use only if you must). OpenSSL 3.0 no longer supports the
Blowfish
+ (and other deprecated) algorithm by default and the new option
``--provider``
+ allows loading the legacy provider to renable these algorithms.
Deprecated features
-------------------
diff --git a/doc/man-sections/generic-options.rst
b/doc/man-sections/generic-options.rst
index e6c1fe455..a8f049f20 100644
--- a/doc/man-sections/generic-options.rst
+++ b/doc/man-sections/generic-options.rst
@@ -280,6 +280,18 @@ which mode OpenVPN is configured as.
This option solves the problem by persisting keys across :code:`SIGUSR1`
resets, so they don't need to be re-read.
+--providers providers
+ Load the list of (OpenSSL) providers. This is mainly useful for using an
+ external provider for key management like tpm2-openssl or to load the
+ legacy provider with
+
+ ::
+
+ --providers legacy default
+
+ Behaviour of changing this option between SIGHUP might not be well behaving.
+ If you need to change/add/remove this option, fully restart OpenVPN.
+
--remap-usr1 signal
Control whether internally or externally generated :code:`SIGUSR1` signals
are remapped to :code:`SIGHUP` (restart without persisting state) or
diff --git a/src/openvpn/crypto_backend.h b/src/openvpn/crypto_backend.h
index 5aab3e1b7..c16837619 100644
--- a/src/openvpn/crypto_backend.h
+++ b/src/openvpn/crypto_backend.h
@@ -78,6 +78,21 @@ void crypto_clear_error(void);
*/
void crypto_init_lib_engine(const char *engine_name);
+
+/**
+ * Load the given (OpenSSL) providers
+ * @param provider name of providers to load
+ * @return reference to the loaded provider
+ */
+provider_t *crypto_load_provider(const char *provider);
+
+/**
+ * Unloads the given (OpenSSL) provider
+ * @param provname name of the provider to unload
+ * @param provider pointer to the provider to unload
+ */
+void crypto_unload_provider(const char* provname, provider_t *provider);
+
#ifdef DMALLOC
/*
* OpenSSL memory debugging. If dmalloc debugging is enabled, tell
diff --git a/src/openvpn/crypto_mbedtls.c b/src/openvpn/crypto_mbedtls.c
index 08b9e004f..39dbf38a5 100644
--- a/src/openvpn/crypto_mbedtls.c
+++ b/src/openvpn/crypto_mbedtls.c
@@ -69,6 +69,19 @@ crypto_init_lib_engine(const char *engine_name)
"available");
}
+provider_t *crypto_load_provider(const char *provider)
+{
+ if (provider)
+ {
+ msg(M_WARN, "Note: mbed TLS provider functionality is not available");
+ }
+ return NULL;
+}
+
+void crypto_unload_provider(const char* provname, provider_t *provider)
+{
+}
+
/*
*
* Functions related to the core crypto library
diff --git a/src/openvpn/crypto_mbedtls.h b/src/openvpn/crypto_mbedtls.h
index 019de01d1..758ab1b40 100644
--- a/src/openvpn/crypto_mbedtls.h
+++ b/src/openvpn/crypto_mbedtls.h
@@ -48,6 +48,9 @@ typedef mbedtls_md_context_t md_ctx_t;
/** Generic HMAC %context. */
typedef mbedtls_md_context_t hmac_ctx_t;
+/* Use a dummy type for the provider */
+typedef void provider_t;
+
/** Maximum length of an IV */
#define OPENVPN_MAX_IV_LENGTH MBEDTLS_MAX_IV_LENGTH
diff --git a/src/openvpn/crypto_openssl.c b/src/openvpn/crypto_openssl.c
index cc1d62210..c9731adb3 100644
--- a/src/openvpn/crypto_openssl.c
+++ b/src/openvpn/crypto_openssl.c
@@ -54,6 +54,9 @@
#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) &&
!defined(LIBRESSL_VERSION_NUMBER)
#include <openssl/kdf.h>
#endif
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+#include <openssl/provider.h>
+#endif
#if defined(_WIN32) && defined(OPENSSL_NO_EC)
#error Windows build with OPENSSL_NO_EC: disabling EC key is not supported.
@@ -149,6 +152,33 @@ crypto_init_lib_engine(const char *engine_name)
#endif
}
+provider_t *
+crypto_load_provider(const char *provider)
+{
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+ /* Load providers into the default (NULL) library context */
+ OSSL_PROVIDER* prov = OSSL_PROVIDER_load(NULL, provider);
+ if (!prov)
+ {
+ crypto_msg(M_FATAL, "failed to load provider '%s'", provider);
+ }
+ return prov;
+#else /* OPENSSL_VERSION_NUMBER >= 0x30000000L */
+ msg(M_WARN, "Note: OpenSSL provider functionality is not available");
+ return NULL;
+#endif
+}
+
+void crypto_unload_provider(const char* provname, provider_t *provider)
+{
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+ if (!OSSL_PROVIDER_unload(provider))
+ {
+ crypto_msg(M_FATAL, "failed to unload provider '%s'", provname);
+ }
+#endif
+}
+
/*
*
* Functions related to the core crypto library
diff --git a/src/openvpn/crypto_openssl.h b/src/openvpn/crypto_openssl.h
index e540a76b9..446f08508 100644
--- a/src/openvpn/crypto_openssl.h
+++ b/src/openvpn/crypto_openssl.h
@@ -33,6 +33,10 @@
#include <openssl/hmac.h>
#include <openssl/md5.h>
#include <openssl/sha.h>
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+#include <openssl/provider.h>
+#endif
+
/** Generic cipher key type %context. */
typedef EVP_CIPHER cipher_kt_t;
@@ -49,12 +53,17 @@ typedef EVP_MD_CTX md_ctx_t;
/** Generic HMAC %context. */
#if OPENSSL_VERSION_NUMBER < 0x30000000L
typedef HMAC_CTX hmac_ctx_t;
+
+/* Use a dummy type for the provider */
+typedef void provider_t;
#else
typedef struct {
OSSL_PARAM params[3];
uint8_t key[EVP_MAX_KEY_LENGTH];
EVP_MAC_CTX *ctx;
} hmac_ctx_t;
+
+typedef OSSL_PROVIDER provider_t;
#endif
/** Maximum length of an IV */
diff --git a/src/openvpn/openvpn.c b/src/openvpn/openvpn.c
index da06f59c2..a18a4dd43 100644
--- a/src/openvpn/openvpn.c
+++ b/src/openvpn/openvpn.c
@@ -112,10 +112,23 @@ void init_early(struct context *c)
/* init verbosity and mute levels */
init_verb_mute(c, IVM_LEVEL_1);
+ /* Initialise OpenSSL provider, this needs to be initialised this
+ * early since option post-processing and also openssl info
+ * printing depends on it */
+ for (int j=1; j < MAX_PARMS && c->options.providers.names[j]; j++)
+ {
+ c->options.providers.providers[j] =
+ crypto_load_provider(c->options.providers.names[j]);
+ }
}
static void uninit_early(struct context *c)
{
+ for (int j=1; j < MAX_PARMS && c->options.providers.providers[j]; j++)
+ {
+ crypto_unload_provider(c->options.providers.names[j],
+ c->options.providers.providers[j]);
+ }
net_ctx_free(&c->net_ctx);
}
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index b5d65d293..b1f9473dc 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -581,6 +581,7 @@ static const char usage_message[] =
" : Use --show-tls to see a list of supported TLS ciphers
(suites).\n"
"--tls-cert-profile p : Set the allowed certificate crypto algorithm
profile\n"
" (default=legacy).\n"
+ "--providers l : A list l of OpenSSL providers to load.\n"
"--tls-timeout n : Packet retransmit timeout on TLS control channel\n"
" if no ACK from remote within n seconds (default=%d).\n"
"--reneg-bytes n : Renegotiate data chan. key after n bytes sent and
recvd.\n"
@@ -8157,6 +8158,13 @@ add_option(struct options *options,
options->engine = "auto";
}
}
+ else if (streq(p[0], "providers") && p[1])
+ {
+ for (size_t j = 1; j < MAX_PARMS && p[j] != NULL;j++)
+ {
+ options->providers.names[j] = p[j];
+ }
+ }
#endif /* ENABLE_CRYPTO_MBEDTLS */
#ifdef ENABLE_PREDICTION_RESISTANCE
else if (streq(p[0], "use-prediction-resistance") && !p[1])
diff --git a/src/openvpn/options.h b/src/openvpn/options.h
index 20b34ed4e..d4f41cd71 100644
--- a/src/openvpn/options.h
+++ b/src/openvpn/options.h
@@ -179,6 +179,14 @@ struct remote_list
struct remote_entry *array[CONNECTION_LIST_SIZE];
};
+struct provider_list
+{
+ /* Names of the providers */
+ const char *names[MAX_PARMS];
+ /* Pointers to the loaded providers to unload them */
+ provider_t *providers[MAX_PARMS];
+};
+
enum vlan_acceptable_frames
{
VLAN_ONLY_TAGGED,
@@ -519,6 +527,7 @@ struct options
const char *ncp_ciphers;
const char *authname;
const char *engine;
+ struct provider_list providers;
bool replay;
bool mute_replay_warnings;
int replay_window;
--
2.33.0
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