Making a gost provider - Add the provider foundation

This adds the source to get a minimal provider that provides...
nothing.

1 files changed, 144 insertions, 0 deletions

diff --git a/gost_prov.c b/gost_prov.c
new file mode 100644
index 0000000..fe65c4d
--- /dev/null
+++ b/gost_prov.c
@@ -0,0 +1,144 @@
+/**********************************************************************
+ *                 gost_prov.c - The provider itself                  *
+ *                                                                    *
+ *      Copyright (c) 2021 Richard Levitte <richard@levitte.org>      *
+ *     This file is distributed under the same license as OpenSSL     *
+ *                                                                    *
+ *                Requires OpenSSL 3.0 for compilation                *
+ **********************************************************************/
+
+#include <openssl/core_dispatch.h>
+#include "gost_prov.h"
+#include "gost_lcl.h"
+#include "prov/err.h"           /* libprov err functions */
+
+/*********************************************************************
+ *
+ *  Errors
+ *
+ *****/
+
+/*
+ * Ugly hack, to get the errors generated by mkerr.pl.  This should ideally
+ * be replaced with a local OSSL_ITEM list of < number, string > pairs as
+ * reason strings, but for now, we will simply use GOST_str_reasons.
+ * Fortunately, the ERR_STRING_DATA structure is compatible with OSSL_ITEM,
+ * so we can return it directly.
+ */
+static struct proverr_functions_st *err_handle;
+#define GOST_PROV
+#include "e_gost_err.c"
+void ERR_GOST_error(int function, int reason, char *file, int line)
+{
+    proverr_new_error(err_handle);
+    proverr_set_error_debug(err_handle, file, line, NULL);
+    proverr_set_error(err_handle, reason, NULL);
+}
+
+/*********************************************************************
+ *
+ *  Provider context
+ *
+ *****/
+
+static void provider_ctx_free(PROV_CTX *ctx)
+{
+    if (ctx != NULL) {
+        ENGINE_free(ctx->e);
+        proverr_free_handle(ctx->proverr_handle);
+        OSSL_LIB_CTX_free(ctx->libctx);
+    }
+    free(ctx);
+}
+
+extern int populate_gost_engine(ENGINE *e);
+static PROV_CTX *provider_ctx_new(const OSSL_CORE_HANDLE *core,
+                                  const OSSL_DISPATCH *in)
+{
+    PROV_CTX *ctx;
+
+    if ((ctx = malloc(sizeof(*ctx))) != NULL
+        && (ctx->proverr_handle = proverr_new_handle(core, in)) != NULL
+        && (ctx->libctx = OSSL_LIB_CTX_new()) != NULL
+        && (ctx->e = ENGINE_new()) != NULL
+        && populate_gost_engine(ctx->e)) {
+        ctx->core_handle = core;
+
+        /* Ugly hack */
+        err_handle = ctx->proverr_handle;
+    } else {
+        provider_ctx_free(ctx);
+        ctx = NULL;
+    }
+    return ctx;
+}
+
+/*********************************************************************
+ *
+ *  Setup
+ *
+ *****/
+
+typedef void (*fptr_t)(void);
+
+/* The function that returns the appropriate algorithm table per operation */
+static const OSSL_ALGORITHM *gost_operation(void *vprovctx,
+                                                int operation_id,
+                                                const int *no_cache)
+{
+    return NULL;
+}
+
+static int gost_get_params(void *provctx, OSSL_PARAM *params)
+{
+    return 1;
+}
+
+static const OSSL_ITEM *gost_get_reason_strings(void *provctx)
+{
+#if 0
+    return reason_strings;
+#endif
+    return (OSSL_ITEM *)GOST_str_reasons;
+}
+
+/* The function that tears down this provider */
+static void gost_teardown(void *vprovctx)
+{
+    provider_ctx_free(vprovctx);
+}
+
+/* The base dispatch table */
+static const OSSL_DISPATCH provider_functions[] = {
+    { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (fptr_t)gost_operation },
+    { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (fptr_t)gost_get_reason_strings },
+    { OSSL_FUNC_PROVIDER_GET_PARAMS, (fptr_t)gost_get_params },
+    { OSSL_FUNC_PROVIDER_TEARDOWN, (fptr_t)gost_teardown },
+    { 0, NULL }
+};
+
+struct prov_ctx_st {
+    void *core_handle;
+    struct proverr_functions_st *err_handle;
+};
+
+#ifdef BUILDING_PROVIDER_AS_LIBRARY
+/*
+ * This allows the provider to be built in library form.  In this case, the
+ * application must add it explicitly like this:
+ *
+ * OSSL_PROVIDER_add_builtin(NULL, "gost", GOST_provider_init);
+ */
+# define OSSL_provider_init GOST_provider_init
+#endif
+
+int OSSL_provider_init(const OSSL_CORE_HANDLE *core,
+                       const OSSL_DISPATCH *in,
+                       const OSSL_DISPATCH **out,
+                       void **vprovctx)
+{
+    if ((*vprovctx = provider_ctx_new(core, in)) == NULL)
+        return 0;
+    *out = provider_functions;
+    return 1;
+}