This allows OpenVPN to load non-default providers. This is mainly
useful for loading the legacy provider with --providers legacy default
Cherry-pick of 08081aa0a153 to release/2.5. Changes.rst has been adjust to
better fit the changes in 2.5.
Signed-off-by: Arne Schwabe <a...@rfc2549.org>
---
Changes.rst | 14 +++++++++++++
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 | 31 ++++++++++++++++++++++++++++
src/openvpn/crypto_openssl.h | 11 ++++++++++
src/openvpn/openvpn.c | 15 +++++++++++++-
src/openvpn/options.c | 8 +++++++
src/openvpn/options.h | 9 ++++++++
10 files changed, 130 insertions(+), 1 deletion(-)
diff --git a/Changes.rst b/Changes.rst
index 45d2c3f39..884c122a9 100644
--- a/Changes.rst
+++ b/Changes.rst
@@ -14,6 +14,20 @@ New features
- upgrade pkcs11-helper to release 1.28.4
+- Limited OpenSSL 3.0 support
+ OpenSSL 3.0 support has been added. OpenSSL 3.0 support in 2.5 relies
+ on the compatiblity layer and full OpenSSL 3.0 support is coming with
+ OpenVPN 2.6. Only features that impact usage directly have been
+ backported:
+
+ ``--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 ``--providers`` allows loading
+ the legacy provider to renable these algorithms.
+
+
Bugfixes
--------
- CVE-2022-0547
diff --git a/doc/man-sections/generic-options.rst
b/doc/man-sections/generic-options.rst
index d5f08839b..18085f9bd 100644
--- a/doc/man-sections/generic-options.rst
+++ b/doc/man-sections/generic-options.rst
@@ -252,6 +252,18 @@ 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 b5a122eee..a9bb38ed2 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 1da99d147..000815209 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 816e1397a..14614a12d 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 0908e9aa1..beeaee4b7 100644
--- a/src/openvpn/crypto_openssl.c
+++ b/src/openvpn/crypto_openssl.c
@@ -51,6 +51,10 @@
#include <openssl/rand.h>
#include <openssl/ssl.h>
+#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.
#endif
@@ -145,6 +149,33 @@ 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 ecc66fbfd..9bb58adae 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;
@@ -49,6 +53,13 @@ typedef EVP_MD_CTX md_ctx_t;
/** Generic HMAC %context. */
typedef HMAC_CTX hmac_ctx_t;
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+/* Use a dummy type for the provider */
+typedef void provider_t;
+#else
+typedef OSSL_PROVIDER provider_t;
+#endif
+
/** Maximum length of an IV */
#define OPENVPN_MAX_IV_LENGTH EVP_MAX_IV_LENGTH
diff --git a/src/openvpn/openvpn.c b/src/openvpn/openvpn.c
index e03d25450..1cd8f1b30 100644
--- a/src/openvpn/openvpn.c
+++ b/src/openvpn/openvpn.c
@@ -112,14 +112,27 @@ 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)
{
net_ctx_free(&c->net_ctx);
+ 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);
}
-
/**************************************************************************/
/**
* OpenVPN's main init-run-cleanup loop.
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index e0b273bdd..f6ef02ae8 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -602,6 +602,7 @@ 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"
@@ -8129,6 +8130,13 @@ add_option(struct options *options,
options->keysize = keysize;
}
#endif
+ 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];
+ }
+ }
#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 251660fdc..372209042 100644
--- a/src/openvpn/options.h
+++ b/src/openvpn/options.h
@@ -176,6 +176,14 @@ 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 *prng_hash;
int prng_nonce_secret_len;
const char *engine;
+ struct provider_list providers;
bool replay;
bool mute_replay_warnings;
int replay_window;
--
2.32.0 (Apple Git-132)
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