File revert-engine-key-removal.patch of Package openvpn

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File revert-engine-key-removal.patch of Package openvpn (Revision 770413bc2bb9559119928c2e344bda49)

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From 6998a420d7bfa5acf9668f7f0411b8adcec70779 Mon Sep 17 00:00:00 2001
From: James Bottomley <James.Bottomley@HansenPartnership.com>
Date: Thu, 16 Nov 2023 07:44:48 -0500
Subject: [PATCH] Revert "Remove openssl engine method for loading the key"

This reverts commit e7427bcbb9b16b52d81c65b01d440a8ecd1e6ea7.
---
 .gitignore                                    |   4 +
 configure.ac                                  |   1 +
 src/openvpn/crypto_openssl.c                  |  60 +++++++++
 src/openvpn/crypto_openssl.h                  |  12 ++
 src/openvpn/ssl_openssl.c                     |   4 +
 tests/unit_tests/Makefile.am                  |   3 +
 tests/unit_tests/engine-key/Makefile.am       |  31 +++++
 .../engine-key/check_engine_keys.sh           |  36 ++++++
 tests/unit_tests/engine-key/libtestengine.c   | 116 ++++++++++++++++++
 tests/unit_tests/engine-key/openssl.cnf.in    |  12 ++
 10 files changed, 279 insertions(+)
 create mode 100644 tests/unit_tests/engine-key/Makefile.am
 create mode 100755 tests/unit_tests/engine-key/check_engine_keys.sh
 create mode 100644 tests/unit_tests/engine-key/libtestengine.c
 create mode 100644 tests/unit_tests/engine-key/openssl.cnf.in

diff --git a/.gitignore b/.gitignore
index a1da3667..ed03aaa9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,10 @@ tests/t_client-*-20??????-??????/
 t_client.rc
 t_client_ips.rc
 tests/unit_tests/**/*_testdriver
+tests/unit_tests/engine-key/client.key
+tests/unit_tests/engine-key/log.txt
+tests/unit_tests/engine-key/openssl.cnf
+tests/unit_tests/engine-key/passwd
 
 src/openvpn/openvpn
 include/openvpn-plugin.h
diff --git a/configure.ac b/configure.ac
index 7e5763d3..614e3a80 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1538,6 +1538,7 @@ AC_CONFIG_FILES([
         tests/unit_tests/openvpn/Makefile
         tests/unit_tests/plugins/Makefile
         tests/unit_tests/plugins/auth-pam/Makefile
+	tests/unit_tests/engine-key/Makefile
 	sample/Makefile
 ])
 AC_CONFIG_FILES([tests/t_client.sh], [chmod +x tests/t_client.sh])
diff --git a/src/openvpn/crypto_openssl.c b/src/openvpn/crypto_openssl.c
index fe1254f8..22c6d684 100644
--- a/src/openvpn/crypto_openssl.c
+++ b/src/openvpn/crypto_openssl.c
@@ -1374,6 +1374,66 @@ memcmp_constant_time(const void *a, const void *b, size_t size)
     return CRYPTO_memcmp(a, b, size);
 }
 
+#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);
+
+    ENGINE_init(engine_persist);
+    pkey = ENGINE_load_private_key(engine_persist, file, ui, ctx);
+    ENGINE_finish(engine_persist);
+    if (!pkey)
+    {
+        crypto_msg(M_FATAL, "Engine could not load key file");
+    }
+
+    UI_destroy_method(ui);
+    return pkey;
+#else  /* if HAVE_OPENSSL_ENGINE */
+    return NULL;
+#endif /* if HAVE_OPENSSL_ENGINE */
+}
+
 #if (OPENSSL_VERSION_NUMBER >= 0x10100000L) && !defined(LIBRESSL_VERSION_NUMBER)
 bool
 ssl_tls1_PRF(const uint8_t *seed, int seed_len, const uint8_t *secret,
diff --git a/src/openvpn/crypto_openssl.h b/src/openvpn/crypto_openssl.h
index c5a53934..32849fd3 100644
--- a/src/openvpn/crypto_openssl.h
+++ b/src/openvpn/crypto_openssl.h
@@ -118,4 +118,16 @@ 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_ */
diff --git a/src/openvpn/ssl_openssl.c b/src/openvpn/ssl_openssl.c
index 23e76231..4c08add1 100644
--- a/src/openvpn/ssl_openssl.c
+++ b/src/openvpn/ssl_openssl.c
@@ -1057,6 +1057,10 @@ tls_ctx_load_priv_file(struct tls_root_ctx *ctx, const char *priv_key_file,
     pkey = PEM_read_bio_PrivateKey(in, NULL,
                                    SSL_CTX_get_default_passwd_cb(ctx->ctx),
                                    SSL_CTX_get_default_passwd_cb_userdata(ctx->ctx));
+    if (!pkey)
+    {
+        pkey = engine_load_key(priv_key_file, ctx->ctx);
+    }
 
     if (!pkey || !SSL_CTX_use_PrivateKey(ssl_ctx, pkey))
     {
diff --git a/tests/unit_tests/Makefile.am b/tests/unit_tests/Makefile.am
index 33fefaac..f27cd90f 100644
--- a/tests/unit_tests/Makefile.am
+++ b/tests/unit_tests/Makefile.am
@@ -2,4 +2,7 @@ AUTOMAKE_OPTIONS = foreign
 
 if ENABLE_UNITTESTS
 SUBDIRS = example_test openvpn plugins
+if OPENSSL_ENGINE
+SUBDIRS += engine-key
+endif
 endif
diff --git a/tests/unit_tests/engine-key/Makefile.am b/tests/unit_tests/engine-key/Makefile.am
new file mode 100644
index 00000000..0c288857
--- /dev/null
+++ b/tests/unit_tests/engine-key/Makefile.am
@@ -0,0 +1,31 @@
+AUTOMAKE_OPTIONS = foreign
+
+check_LTLIBRARIES = libtestengine.la
+conffiles = openssl.cnf
+EXTRA_DIST = \
+	openssl.cnf.in \
+	check_engine_keys.sh
+
+TESTS_ENVIRONMENT = srcdir="$(abs_srcdir)"; \
+	builddir="$(abs_builddir)"; \
+	top_builddir="$(top_builddir)"; \
+	top_srcdir="$(top_srcdir)"; \
+	export srcdir builddir top_builddir top_srcdir;
+
+if !CROSS_COMPILING
+TESTS = check_engine_keys.sh
+endif
+check_engine_keys.sh: $(conffiles)
+
+CLEANFILES = \
+	client.key \
+	passwd \
+	log.txt \
+	$(conffiles)
+
+openssl.cnf: $(srcdir)/openssl.cnf.in
+	sed "s|ABSBUILDDIR|$(abs_builddir)|" < $(srcdir)/openssl.cnf.in > $@
+
+libtestengine_la_SOURCES = libtestengine.c
+libtestengine_la_LDFLAGS = @TEST_LDFLAGS@ -rpath /lib -shrext .so
+libtestengine_la_CFLAGS = @TEST_CFLAGS@ -I$(openvpn_srcdir) -I$(compat_srcdir)
diff --git a/tests/unit_tests/engine-key/check_engine_keys.sh b/tests/unit_tests/engine-key/check_engine_keys.sh
new file mode 100755
index 00000000..12dd2301
--- /dev/null
+++ b/tests/unit_tests/engine-key/check_engine_keys.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+OPENSSL_CONF="${builddir}/openssl.cnf"
+export OPENSSL_CONF
+
+password='AT3S4PASSWD'
+
+key="${builddir}/client.key"
+pwdfile="${builddir}/passwd"
+
+# create an engine key for us
+sed 's/PRIVATE KEY/TEST ENGINE KEY/' < ${top_srcdir}/sample/sample-keys/client.key > ${key}
+echo "$password" > $pwdfile
+
+# our version of grep to output log.txt on failure in case it's an openssl
+# error mismatch and the grep expression needs updating
+loggrep() {
+    egrep -q "$1" log.txt || { echo '---- begin log.txt ----'; cat log.txt; echo '--- end log.txt ---'; return 1; }
+}
+
+# note here we've induced a mismatch in the client key and the server
+# cert which openvpn should report and die.  Check that it does.  Note
+# also that this mismatch depends on openssl not openvpn, so it is
+# somewhat fragile
+${top_builddir}/src/openvpn/openvpn --cd ${top_srcdir}/sample --config sample-config-files/loopback-server --engine testengine --key ${key} --askpass $pwdfile > log.txt 2>&1
+
+# first off check we died because of a key mismatch.  If this doesn't
+# pass, suspect openssl of returning different messages and update the
+# test accordingly
+loggrep '(x509 certificate routines:(X509_check_private_key)?:key values mismatch|func$128$:reason$116$)' log.txt || { echo "Key mismatch not detected"; exit 1; }
+
+# now look for the engine prints (these are under our control)
+loggrep 'ENGINE: engine_init called' || { echo "Engine initialization not detected"; exit 1; }
+loggrep 'ENGINE: engine_load_key called' || { echo "Key was not loaded from engine"; exit 1; }
+loggrep "ENGINE: engine_load_key got password ${password}" || { echo "Key password was not retrieved by the engine"; exit 1; }
+exit 0
diff --git a/tests/unit_tests/engine-key/libtestengine.c b/tests/unit_tests/engine-key/libtestengine.c
new file mode 100644
index 00000000..8bcfa92e
--- /dev/null
+++ b/tests/unit_tests/engine-key/libtestengine.c
@@ -0,0 +1,116 @@
+#include <string.h>
+#include <openssl/engine.h>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+
+static char *engine_id = "testengine";
+static char *engine_name = "Engine for testing openvpn engine key support";
+
+static int is_initialized = 0;
+
+static int
+engine_init(ENGINE *e)
+{
+    is_initialized = 1;
+    fprintf(stderr, "ENGINE: engine_init called\n");
+    return 1;
+}
+
+static int
+engine_finish(ENGINE *e)
+{
+    fprintf(stderr, "ENGINE: engine_finsh called\n");
+    is_initialized = 0;
+    return 1;
+}
+
+static EVP_PKEY *
+engine_load_key(ENGINE *e, const char *key_id,
+                UI_METHOD *ui_method, void *cb_data)
+{
+    BIO *b;
+    EVP_PKEY *pkey;
+    PKCS8_PRIV_KEY_INFO *p8inf;
+    UI *ui;
+    char auth[256];
+
+    fprintf(stderr, "ENGINE: engine_load_key called\n");
+
+    if (!is_initialized)
+    {
+        fprintf(stderr, "Load Key called without correct initialization\n");
+        return NULL;
+    }
+    b = BIO_new_file(key_id, "r");
+    if (!b)
+    {
+        fprintf(stderr, "File %s does not exist or cannot be read\n", key_id);
+        return 0;
+    }
+    /* Basically read an EVP_PKEY private key file with different
+     * PEM guards --- we are a test engine */
+    p8inf = PEM_ASN1_read_bio((d2i_of_void *)d2i_PKCS8_PRIV_KEY_INFO,
+                              "TEST ENGINE KEY", b,
+                              NULL, NULL, NULL);
+    BIO_free(b);
+    if (!p8inf)
+    {
+        fprintf(stderr, "Failed to read engine private key\n");
+        return NULL;
+    }
+    pkey = EVP_PKCS82PKEY(p8inf);
+
+    /* now we have a private key, pretend it had a password
+     * this verifies the password makes it through openvpn OK */
+    ui = UI_new();
+
+    if (ui_method)
+    {
+        UI_set_method(ui, ui_method);
+    }
+
+    UI_add_user_data(ui, cb_data);
+
+    if (UI_add_input_string(ui, "enter test engine key",
+                            UI_INPUT_FLAG_DEFAULT_PWD,
+                            auth, 0, sizeof(auth)) == 0)
+    {
+        fprintf(stderr, "UI_add_input_string failed\n");
+        goto out;
+    }
+
+    if (UI_process(ui))
+    {
+        fprintf(stderr, "UI_process failed\n");
+        goto out;
+    }
+
+    fprintf(stderr, "ENGINE: engine_load_key got password %s\n", auth);
+
+out:
+    UI_free(ui);
+
+    return pkey;
+}
+
+
+static int
+engine_bind_fn(ENGINE *e, const char *id)
+{
+    if (id && strcmp(id, engine_id) != 0)
+    {
+        return 0;
+    }
+    if (!ENGINE_set_id(e, engine_id)
+        || !ENGINE_set_name(e, engine_name)
+        || !ENGINE_set_init_function(e, engine_init)
+        || !ENGINE_set_finish_function(e, engine_finish)
+        || !ENGINE_set_load_privkey_function(e, engine_load_key))
+    {
+        return 0;
+    }
+    return 1;
+}
+
+IMPLEMENT_DYNAMIC_CHECK_FN()
+IMPLEMENT_DYNAMIC_BIND_FN(engine_bind_fn)
diff --git a/tests/unit_tests/engine-key/openssl.cnf.in b/tests/unit_tests/engine-key/openssl.cnf.in
new file mode 100644
index 00000000..5eda9fa9
--- /dev/null
+++ b/tests/unit_tests/engine-key/openssl.cnf.in
@@ -0,0 +1,12 @@
+HOME		= .
+openssl_conf	= openssl_init
+
+[req]
+[openssl_init]
+engines		= engines_section
+
+[engines_section]
+testengine	= testengine_section
+
+[testengine_section]
+dynamic_path	= ABSBUILDDIR/.libs/libtestengine.so
-- 
2.35.3

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File revert-engine-key-removal.patch of Package openvpn (Revision 770413bc2bb9559119928c2e344bda49)

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