text: /*
   * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
   *
   * Licensed under the Apache License, Version 2.0 (the "License").
   * You may not use this file except in compliance with the License.
   * A copy of the License is located at
   *
   *  http://aws.amazon.com/apache2.0
   *
   * or in the "license" file accompanying this file. This file is distributed
   * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
   * express or implied. See the License for the specific language governing
   * permissions and limitations under the License.
   */
  
  #include <assert.h>
  #include <cbmc_proof/cbmc_utils.h>
  #include <cbmc_proof/make_common_datastructures.h>
  
  #include "api/s2n.h"
  #include "utils/s2n_blob.h"
  
  void s2n_free_harness()
  {
      /* Non-deterministic inputs. */
      struct s2n_blob *blob = cbmc_allocate_s2n_blob();
  
      /* Assumptions. */
      nondet_s2n_mem_init();
      __CPROVER_assume(s2n_result_is_ok(s2n_blob_validate(blob)));
      const struct s2n_blob old_blob = *blob;
  
      /* Operation under verification. */
      int result = s2n_free(blob);
      if (result == S2N_SUCCESS) {
          /* Postconditions. */
          assert(S2N_IMPLIES(old_blob.allocated, blob->data == NULL));
          assert_all_zeroes(blob, sizeof(*blob));
          if (old_blob.size != 0 && s2n_blob_is_growable(&old_blob)) {
              assert(!S2N_MEM_IS_READABLE(blob->data, old_blob.size));
          }
      }
  
      /* Cleanup after expected error cases, for memory leak check. */
      bool failed_before_free = (s2n_errno == S2N_ERR_NOT_INITIALIZED) || (s2n_errno == S2N_ERR_FREE_STATIC_BLOB);
      if ((result != S2N_SUCCESS && failed_before_free) || !s2n_blob_is_growable(blob)) {
          /* 1. `s2n_free` failed _before_ calling `free`, either because:
                (a) s2n was not initialized, or (b) the blob was a static blob.
             2. `blob` is not growable, then `s2n_free` is not supposed to `free` even if successful.
          */
          free(blob->data);
      }
      /* 3. free our heap-allocated `blob` since `s2n_free` only `free`s the contents. */
      free(blob);
  }
  