Add internal function ossl_algorithm_do_all()

This function is used to traverse all the implementations provided by
one provider, or all implementation for a specific operation across
all loaded providers, or both, and execute a given function for each
occurence.

This will be used by ossl_method_construct(), but also by information
processing functions.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9356)

2 files changed, 77 insertions, 1 deletions

diff --git a/crypto/build.info b/crypto/build.info
index 088ec87310..3f9eb52bb6 100644
--- a/crypto/build.info
+++ b/crypto/build.info
@@ -59,7 +59,8 @@ IF[{- !$disabled{asm} && $config{processor} ne '386' -}]
 ENDIF
 
 # The Core
-$CORE_COMMON=provider_core.c provider_predefined.c core_fetch.c core_namemap.c
+$CORE_COMMON=provider_core.c provider_predefined.c \
+        core_fetch.c core_algorithm.c core_namemap.c
 
 SOURCE[../libcrypto]=$CORE_COMMON provider_conf.c
 SOURCE[../providers/fips]=$CORE_COMMON
diff --git a/crypto/core_algorithm.c b/crypto/core_algorithm.c
new file mode 100644
index 0000000000..f88a0458ec
--- /dev/null
+++ b/crypto/core_algorithm.c
@@ -0,0 +1,75 @@
+/*
+ * 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 <openssl/core.h>
+#include <openssl/core_numbers.h>
+#include "internal/core.h"
+#include "internal/property.h"
+#include "internal/provider.h"
+
+struct algorithm_data_st {
+    OPENSSL_CTX *libctx;
+    int operation_id;            /* May be zero for finding them all */
+    void (*fn)(OSSL_PROVIDER *, const OSSL_ALGORITHM *, int no_store,
+               void *data);
+    void *data;
+};
+
+static int algorithm_do_this(OSSL_PROVIDER *provider, void *cbdata)
+{
+    struct algorithm_data_st *data = cbdata;
+    int no_store = 0;    /* Assume caching is ok */
+    int first_operation = 1;
+    int last_operation = OSSL_OP__HIGHEST;
+    int cur_operation;
+    int ok = 0;
+
+    if (data->operation_id != 0)
+        first_operation = last_operation = data->operation_id;
+
+    for (cur_operation = first_operation;
+         cur_operation <= last_operation;
+         cur_operation++) {
+        const OSSL_ALGORITHM *map =
+            ossl_provider_query_operation(provider, data->operation_id,
+                                          &no_store);
+
+        if (map == NULL)
+            break;
+
+        ok = 1;                  /* As long as we've found *something* */
+        while (map->algorithm_name != NULL) {
+            const OSSL_ALGORITHM *thismap = map++;
+
+            data->fn(provider, thismap, no_store, data->data);
+        }
+    }
+
+    return ok;
+}
+
+void ossl_algorithm_do_all(OPENSSL_CTX *libctx, int operation_id,
+                           OSSL_PROVIDER *provider,
+                           void (*fn)(OSSL_PROVIDER *provider,
+                                      const OSSL_ALGORITHM *algo,
+                                      int no_store, void *data),
+                           void *data)
+{
+    struct algorithm_data_st cbdata;
+
+    cbdata.libctx = libctx;
+    cbdata.operation_id = operation_id;
+    cbdata.fn = fn;
+    cbdata.data = data;
+
+    if (provider == NULL)
+        ossl_provider_forall_loaded(libctx, algorithm_do_this, &cbdata);
+    else
+        algorithm_do_this(provider, &cbdata);
+}