CORE: query for operations only once per provider (unless no_store is true)

When a desired algorithm wasn't available, we didn't register anywhere
that an attempt had been made, with the result that next time the same
attempt was made, the whole process would be done again.

To avoid this churn, we register a bit for each operation that has
been queried in the libcrypto provider object, and test it before
trying the same query and method construction loop again.

If course, if the provider has told us not to cache, we don't register
this bit.

Fixes #11814

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11842)

1 files changed, 43 insertions, 5 deletions

diff --git a/crypto/core_algorithm.c b/crypto/core_algorithm.c
index 79625fdea6..5c019f0405 100644
--- a/crypto/core_algorithm.c
+++ b/crypto/core_algorithm.c
@@ -16,8 +16,11 @@
 struct algorithm_data_st {
     OPENSSL_CTX *libctx;
     int operation_id;            /* May be zero for finding them all */
+    int (*pre)(OSSL_PROVIDER *, int operation_id, void *data, int *result);
     void (*fn)(OSSL_PROVIDER *, const OSSL_ALGORITHM *, int no_store,
                void *data);
+    int (*post)(OSSL_PROVIDER *, int operation_id, int no_store, void *data,
+                int *result);
     void *data;
 };
 
@@ -36,19 +39,48 @@ static int algorithm_do_this(OSSL_PROVIDER *provider, void *cbdata)
     for (cur_operation = first_operation;
          cur_operation <= last_operation;
          cur_operation++) {
-        const OSSL_ALGORITHM *map =
-            ossl_provider_query_operation(provider, cur_operation,
-                                          &no_store);
+        const OSSL_ALGORITHM *map = NULL;
+        int ret;
 
+        /* Do we fulfill pre-conditions? */
+        if (data->pre == NULL) {
+            /* If there is no pre-condition function, assume "yes" */
+            ret = 1;
+        } else {
+            if (!data->pre(provider, cur_operation, data->data, &ret))
+                /* Error, bail out! */
+                return 0;
+        }
+
+        /* If pre-condition not fulfilled, go to the next operation */
+        if (!ret)
+            continue;
+
+        map = ossl_provider_query_operation(provider, cur_operation,
+                                            &no_store);
         if (map == NULL)
             continue;
 
-        ok = 1;                  /* As long as we've found *something* */
         while (map->algorithm_names != NULL) {
             const OSSL_ALGORITHM *thismap = map++;
 
             data->fn(provider, thismap, no_store, data->data);
         }
+
+        /* Do we fulfill post-conditions? */
+        if (data->post == NULL) {
+            /* If there is no post-condition function, assume "yes" */
+            ret = 1;
+        } else {
+            if (!data->post(provider, cur_operation, no_store, data->data,
+                            &ret))
+                /* Error, bail out! */
+                return 0;
+        }
+
+        /* If post-condition fulfilled, set general success */
+        if (ret)
+            ok = 1;
     }
 
     return ok;
@@ -56,16 +88,22 @@ static int algorithm_do_this(OSSL_PROVIDER *provider, void *cbdata)
 
 void ossl_algorithm_do_all(OPENSSL_CTX *libctx, int operation_id,
                            OSSL_PROVIDER *provider,
+                           int (*pre)(OSSL_PROVIDER *, int operation_id,
+                                      void *data, int *result),
                            void (*fn)(OSSL_PROVIDER *provider,
                                       const OSSL_ALGORITHM *algo,
                                       int no_store, void *data),
+                           int (*post)(OSSL_PROVIDER *, int operation_id,
+                                       int no_store, void *data, int *result),
                            void *data)
 {
-    struct algorithm_data_st cbdata;
+    struct algorithm_data_st cbdata = { 0, };
 
     cbdata.libctx = libctx;
     cbdata.operation_id = operation_id;
+    cbdata.pre = pre;
     cbdata.fn = fn;
+    cbdata.post = post;
     cbdata.data = data;
 
     if (provider == NULL)