@@ -63,6 +63,7 @@
#endif
#if HAVE_OPENSSL_ENGINE
+#include <openssl/ui.h>
#include <openssl/engine.h>
static bool engine_initialized = false; /* GLOBAL */
@@ -969,4 +970,56 @@ hmac_ctx_final(HMAC_CTX *ctx, uint8_t *dst)
HMAC_Final(ctx, dst, &in_hmac_len);
}
+#if HAVE_OPENSSL_ENGINE
+static int
+ui_reader(UI *ui, UI_STRING *uis)
+{
+ SSL_CTX *ctx = UI_get0_user_data(ui);
+
+ if (UI_get_string_type(uis) == UIT_PROMPT) {
+ pem_password_cb *cb = SSL_CTX_get_default_passwd_cb(ctx);
+ void *d = SSL_CTX_get_default_passwd_cb_userdata(ctx);
+ char password[64];
+
+ cb(password, sizeof(password), 0, d);
+ UI_set_result(ui, uis, password);
+
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+EVP_PKEY *
+engine_load_key(const char *file, SSL_CTX *ctx)
+{
+#if HAVE_OPENSSL_ENGINE
+ UI_METHOD *ui;
+ EVP_PKEY *pkey;
+
+ if (!engine_persist)
+ return NULL;
+
+ /* this will print out the error from BIO_read */
+ crypto_msg(M_INFO, "PEM_read_bio failed, now trying engine method to load private key");
+
+ ui = UI_create_method("openvpn");
+ if (!ui) {
+ crypto_msg(M_FATAL, "Engine UI creation failed");
+ return NULL;
+ }
+
+ UI_method_set_reader(ui, ui_reader);
+
+ pkey = ENGINE_load_private_key(engine_persist, file, ui, ctx);
+ if (!pkey)
+ crypto_msg(M_FATAL, "Engine could not load key file");
+ out:
+ UI_destroy_method(ui);
+ return pkey;
+#else
+ return NULL;
+#endif
+}
+
#endif /* ENABLE_CRYPTO_OPENSSL */
@@ -101,5 +101,17 @@ void crypto_print_openssl_errors(const unsigned int flags);
msg((flags), __VA_ARGS__); \
} while (false)
+/**
+ * Load a key file from an engine
+ *
+ * @param file The engine file to load
+ * @param ui The UI method for the password prompt
+ * @param data The data to pass to the UI method
+ *
+ * @return The private key if successful or NULL if not
+ */
+EVP_PKEY *
+engine_load_key(const char *file, SSL_CTX *ctx);
+
#endif /* CRYPTO_OPENSSL_H_ */
@@ -907,7 +907,11 @@ tls_ctx_load_priv_file(struct tls_root_ctx *ctx, const char *priv_key_file,
SSL_CTX_get_default_passwd_cb_userdata(ctx->ctx));
if (!pkey)
{
- goto end;
+ pkey = engine_load_key(priv_key_file, ctx->ctx);
+ if (!pkey)
+ {
+ goto end;
+ }
}
if (!SSL_CTX_use_PrivateKey(ssl_ctx, pkey))
As well as doing crypto acceleration, engines can also be used to load key files. If the engine is set, and the private key loading fails for bio methods, this patch makes openvpn try to get the engine to load the key. If that succeeds, we end up using an engine based key. This can be used with the openssl tpm engines to make openvpn use a TPM wrapped key file. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> --- v2: add better configuration guarding v4: - use crypto_msg() instead of raw openssl prints - remove ENGINE_init/finish(). Openvpn already initializes the engine so doing a second initialization is wrong. - don't clear the openssl errors from the BIO_read failure just in case they might be useful. - ad ui.h include for openssl 1.1 build failure --- src/openvpn/crypto_openssl.c | 53 ++++++++++++++++++++++++++++++++++++++++++++ src/openvpn/crypto_openssl.h | 12 ++++++++++ src/openvpn/ssl_openssl.c | 6 ++++- 3 files changed, 70 insertions(+), 1 deletion(-)