New sample program to benchmark certificate loading

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/programs/x509/load_roots.c b/programs/x509/load_roots.c
new file mode 100644
index 0000000..5baf08b
--- /dev/null
+++ b/programs/x509/load_roots.c
@@ -0,0 +1,207 @@
+/*
+ *  Root CA reading application
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ *
+ *  This file is provided under the Apache License 2.0, or the
+ *  GNU General Public License v2.0 or later.
+ *
+ *  **********
+ *  Apache License 2.0:
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License 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.
+ *
+ *  **********
+ *
+ *  **********
+ *  GNU General Public License v2.0 or later:
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  **********
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdio.h>
+#include <stdlib.h>
+#define mbedtls_time            time
+#define mbedtls_time_t          time_t
+#define mbedtls_fprintf         fprintf
+#define mbedtls_printf          printf
+#define mbedtls_exit            exit
+#define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
+
+#if !defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_FS_IO) ||  \
+    !defined(MBEDTLS_TIMING_C)
+int main( void )
+{
+    mbedtls_printf("MBEDTLS_X509_CRT_PARSE_C and/or MBEDTLS_FS_IO and/or "
+           "MBEDTLS_TIMING_C not defined.\n");
+    mbedtls_exit( 0 );
+}
+#else
+
+#include "mbedtls/error.h"
+#include "mbedtls/timing.h"
+#include "mbedtls/x509_crt.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define DFL_ITERATIONS          1
+#define DFL_PRIME_CACHE         1
+
+#define USAGE \
+    "\n usage: load_roots param=<>... [--] {FILE|DIR}...\n"   \
+    "\n acceptable parameters:\n"                       \
+    "    iterations=%%d        Iteration count (not including cache priming); default: 1\n"  \
+    "    prime=%%d             Prime the disk read cache? Default: 1 (yes)\n"  \
+    "\n"
+
+
+/*
+ * global options
+ */
+struct options
+{
+    const char **filenames;     /* NULL-terminated list of file names */
+    unsigned iterations;        /* Number of iterations to time */
+    int prime_cache;            /* Prime the disk read cache? */
+} opt;
+
+
+int read_certificates( const char *const *filenames )
+{
+    mbedtls_x509_crt cas;
+    int ret = 0;
+    const char *const *cur;
+    char error_message[200];
+
+    mbedtls_x509_crt_init( &cas );
+
+    for( cur = filenames; *cur != NULL; cur++ )
+    {
+        ret = mbedtls_x509_crt_parse_file( &cas, *cur );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, error_message, sizeof( error_message ) );
+            printf( "\n%s: -0x%04x (%s)\n", *cur, -ret, error_message );
+            goto exit;
+        }
+    }
+
+exit:
+    mbedtls_x509_crt_free( &cas );
+    return( ret == 0 );
+}
+
+int main( int argc, char *argv[] )
+{
+    int exit_code = MBEDTLS_EXIT_FAILURE;
+    unsigned i, j;
+    struct mbedtls_timing_hr_time timer;
+    unsigned long ms;
+
+    if( argc == 0 )
+    {
+        mbedtls_printf( USAGE );
+        goto exit;
+    }
+
+    opt.filenames = NULL;
+    opt.iterations = DFL_ITERATIONS;
+    opt.prime_cache = DFL_PRIME_CACHE;
+
+    for( i = 1; i < (unsigned) argc; i++ )
+    {
+        char *p = argv[i];
+        char *q = NULL;
+
+        if( strcmp( p, "--" ) == 0 )
+            break;
+        if( ( q = strchr( p, '=' ) ) == NULL )
+            break;
+        *q++ = '\0';
+
+        for( j = 0; p + j < q; j++ )
+        {
+            if( argv[i][j] >= 'A' && argv[i][j] <= 'Z' )
+                argv[i][j] |= 0x20;
+        }
+
+        if( strcmp( p, "iterations" ) == 0 )
+        {
+            opt.iterations = atoi( q );
+        }
+        else if( strcmp( p, "prime" ) == 0 )
+        {
+            opt.iterations = atoi( q ) != 0;
+        }
+        else
+            mbedtls_printf( "Unknown option: %s\n", p );
+    }
+
+    opt.filenames = (const char**) argv + i;
+    if( *opt.filenames == 0 )
+    {
+        mbedtls_printf( "Missing list of certificate files to parse\n" );
+        goto exit;
+    }
+
+    mbedtls_printf( "Parsing %u certificates", argc - i );
+    if( opt.prime_cache )
+    {
+        if( ! read_certificates( opt.filenames ) )
+            goto exit;
+        mbedtls_printf( " " );
+    }
+
+    (void) mbedtls_timing_get_timer( &timer, 1 );
+    for( i = 1; i <= opt.iterations; i++ )
+    {
+        if( ! read_certificates( opt.filenames ) )
+            goto exit;
+        mbedtls_printf( "." );
+    }
+    ms = mbedtls_timing_get_timer( &timer, 0 );
+    mbedtls_printf( "\n%u iterations -> %lu ms\n", opt.iterations, ms );
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+    mbedtls_exit( exit_code );
+}
+#endif /* necessary configuration */