Replumbing: add a configuration module for providers

This configuration module supports a configuration structure pretty
much like the engine configuration module, i.e. something like this:

    openssl_conf = openssl_init

    [openssl_init]
    providers = provider_section

    [provider_section]
    # Configure the provider named "foo"
    foo = foo_section
    # Configure the provider named "bar"
    bar = bar_section

    [foo_section]
    # Override name given in the provider section
    identity = myfoo
    # The exact path of the module.  This is platform specific
    module_path = /opt/openssl/modules/foo.so
    # Whether it should be automatically activated.  Value is unimportant
    activate = whatever

    # Anything else goes as well, and becomes parameters that the
    # provider can get
    what = 1
    # sub-sections will be followed as well
    ever = ever_section

    [ever_section]
    cookie = monster

All the configurations in a provider section and its sub-sections
become parameters for the provider to get, i.e. the "foo" provider
will be able to get values for the following keys (with associated
values shown):

    identity            => myfoo
    module_path         => /opt/openssl/modules/foo.so
    activate            => whatever
    what                => 1
    ever.cookie         => monster

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8549)

1 files changed, 179 insertions, 0 deletions

diff --git a/crypto/provider_conf.c b/crypto/provider_conf.c
new file mode 100644
index 0000000000..9d9b7a1348
--- /dev/null
+++ b/crypto/provider_conf.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <string.h>
+#include <openssl/trace.h>
+#include <openssl/err.h>
+#include <openssl/conf.h>
+#include <openssl/safestack.h>
+#include "internal/provider.h"
+
+/* PROVIDER config module */
+
+DEFINE_STACK_OF(OSSL_PROVIDER)
+static STACK_OF(OSSL_PROVIDER) *activated_providers = NULL;
+
+static const char *skip_dot(const char *name)
+{
+    const char *p = strchr(name, '.');
+
+    if (p != NULL)
+        return p + 1;
+    return name;
+}
+
+static int provider_conf_params(OSSL_PROVIDER *prov,
+                                const char *name, const char *value,
+                                const CONF *cnf)
+{
+    STACK_OF(CONF_VALUE) *sect;
+    int ok = 1;
+
+    OSSL_TRACE2(PROVIDER_CONF, "PROVIDER conf: %s = %s\n", name, value);
+
+    sect = NCONF_get_section(cnf, value);
+    if (sect != NULL) {
+        int i;
+        char buffer[512];
+        size_t buffer_len = 0;
+
+        if (name != NULL) {
+            OPENSSL_strlcpy(buffer, name, sizeof(buffer));
+            OPENSSL_strlcat(buffer, ".", sizeof(buffer));
+            buffer_len = strlen(buffer);
+        }
+
+        for (i = 0; i < sk_CONF_VALUE_num(sect); i++) {
+            CONF_VALUE *sectconf = sk_CONF_VALUE_value(sect, i);
+
+            if (buffer_len + strlen(sectconf->name) >= sizeof(buffer))
+                return 0;
+            buffer[buffer_len] = '\0';
+            OPENSSL_strlcat(buffer, sectconf->name, sizeof(buffer));
+            if (!provider_conf_params(prov, buffer, sectconf->value, cnf))
+                return 0;
+        }
+    } else {
+        ok = ossl_provider_add_parameter(prov, name, value);
+    }
+
+    return ok;
+}
+
+static int provider_conf_load(OPENSSL_CTX *libctx, const char *name,
+                              const char *value, const CONF *cnf)
+{
+    int i;
+    STACK_OF(CONF_VALUE) *ecmds;
+    int soft = 0;
+    OSSL_PROVIDER *prov = NULL;
+    const char *path = NULL;
+    long activate = 0;
+    int ok = 0;
+
+    name = skip_dot(name);
+    OSSL_TRACE1(PROVIDER_CONF, "Configuring provider %s\n", name);
+    /* Value is a section containing PROVIDER commands */
+    ecmds = NCONF_get_section(cnf, value);
+
+    if (!ecmds) {
+        CRYPTOerr(CRYPTO_F_PROVIDER_CONF_LOAD, CRYPTO_R_PROVIDER_SECTION_ERROR);
+        return 0;
+    }
+
+    /* Find the needed data first */
+    for (i = 0; i < sk_CONF_VALUE_num(ecmds); i++) {
+        CONF_VALUE *ecmd = sk_CONF_VALUE_value(ecmds, i);
+        const char *confname = skip_dot(ecmd->name);
+        const char *confvalue = ecmd->value;
+
+        OSSL_TRACE2(PROVIDER_CONF, "PROVIDER conf: %s = %s\n",
+                    confname, confvalue);
+
+        /* First handle some special pseudo confs */
+
+        /* Override provider name to use */
+        if (strcmp(confname, "identity") == 0)
+            name = confvalue;
+        else if (strcmp(confname, "soft_load") == 0)
+            soft = 1;
+        /* Load a dynamic PROVIDER */
+        else if (strcmp(confname, "module") == 0)
+            path = confvalue;
+        else if (strcmp(confname, "activate") == 0)
+            activate = 1;
+    }
+
+    prov = ossl_provider_new(libctx, name, NULL);
+    if (prov == NULL) {
+        if (soft)
+            ERR_clear_error();
+        return 0;
+    }
+
+    if (path != NULL)
+        ossl_provider_set_module_path(prov, path);
+
+    ok = provider_conf_params(prov, NULL, value, cnf);
+
+    if (ok && activate) {
+        if (!ossl_provider_activate(prov)) {
+            ok = 0;
+        } else {
+            if (activated_providers == NULL)
+                activated_providers = sk_OSSL_PROVIDER_new_null();
+            sk_OSSL_PROVIDER_push(activated_providers, prov);
+            ok = 1;
+        }
+    }
+
+    if (!(activate && ok))
+        ossl_provider_free(prov);
+
+    return ok;
+}
+
+static int provider_conf_init(CONF_IMODULE *md, const CONF *cnf)
+{
+    STACK_OF(CONF_VALUE) *elist;
+    CONF_VALUE *cval;
+    int i;
+
+    OSSL_TRACE2(PROVIDER_CONF, "Loading provider module: name %s, value %s\n",
+                CONF_imodule_get_name(md), CONF_imodule_get_value(md));
+    /* Value is a section containing PROVIDERs to configure */
+    elist = NCONF_get_section(cnf, CONF_imodule_get_value(md));
+
+    if (!elist) {
+        CRYPTOerr(CRYPTO_F_PROVIDER_CONF_INIT,
+                  CRYPTO_R_PROVIDER_SECTION_ERROR);
+        return 0;
+    }
+
+    for (i = 0; i < sk_CONF_VALUE_num(elist); i++) {
+        cval = sk_CONF_VALUE_value(elist, i);
+        if (!provider_conf_load(NULL, cval->name, cval->value, cnf))
+            return 0;
+    }
+
+    return 1;
+}
+
+
+static void provider_conf_deinit(CONF_IMODULE *md)
+{
+    sk_OSSL_PROVIDER_pop_free(activated_providers, ossl_provider_free);
+    activated_providers = NULL;
+    OSSL_TRACE(PROVIDER_CONF, "Cleaned up providers\n");
+}
+
+void ossl_provider_add_conf_module(void)
+{
+    CONF_module_add("providers", provider_conf_init, provider_conf_deinit);
+}