Implement table-driven option parsing that allows an application to

specify what its valid options are and where it wants them to be stored.
This also allows for usage to be generated, almost for free, ensuring
that the options and usage are automatically kept in sync.

This will allow for a single option parsing implementation, rather than the
current one-hand-rolled-option-parsing-and-random-usage-implementation per
application.

As a starting point, port the openssl(1) rand application to the new option
parsing and usage (along with associated code clean up).

With input from doug@.

ok bcook@ doug@

1 files changed, 75 insertions, 74 deletions

diff --git a/src/usr.bin/openssl/rand.c b/src/usr.bin/openssl/rand.c
index 0800157a35..61c7013340 100644
--- a/src/usr.bin/openssl/rand.c
+++ b/src/usr.bin/openssl/rand.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rand.c,v 1.1 2014/08/26 17:47:25 jsing Exp $ */
+/* $OpenBSD: rand.c,v 1.2 2014/08/27 14:59:44 jsing Exp $ */
 /* ====================================================================
  * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
  *
@@ -63,123 +63,124 @@
 #include <openssl/err.h>
 #include <openssl/rand.h>
 
-/* -out file         - write to file
- * -base64           - base64 encode output
- * -hex              - hex encode output
- * num               - write 'num' bytes
- */
+struct {
+        int base64;
+        char *engine;
+        int hex;
+        char *outfile;
+} rand_config;
+
+struct option rand_options[] = {
+        {
+                .name = "base64",
+                .desc = "Perform base64 encoding on output",
+                .type = OPTION_FLAG,
+                .opt.flag = &rand_config.base64,
+        },
+#ifndef OPENSSL_NO_ENGINE
+        {
+                .name = "engine",
+                .argname = "id",
+                .desc = "Use the engine specified by the given identifier",
+                .type = OPTION_ARG,
+                .opt.arg = &rand_config.engine,
+        },
+#endif
+        {
+                .name = "hex",
+                .desc = "Hexadecimal output",
+                .type = OPTION_FLAG,
+                .opt.flag = &rand_config.hex,
+        },
+        {
+                .name = "out",
+                .argname = "file",
+                .desc = "Write to the given file instead of standard output",
+                .type = OPTION_ARG,
+                .opt.arg = &rand_config.outfile,
+        },
+        {},
+};
+
+static void
+rand_usage()
+{
+        fprintf(stderr,
+            "usage: rand [-base64 | -hex] [-engine id] [-out file] num\n");
+        options_usage(rand_options);
+}
 
 int rand_main(int, char **);
 
 int
 rand_main(int argc, char **argv)
 {
-        int i, r, ret = 1;
-        int badopt;
-        char *outfile = NULL;
-        int base64 = 0;
-        int hex = 0;
-        BIO *out = NULL;
+        char *num_bytes = NULL;
+        int ret = 1;
+        int badopt = 0;
         int num = -1;
-#ifndef OPENSSL_NO_ENGINE
-        char *engine = NULL;
-#endif
+        int i, r;
+        BIO *out = NULL;
 
-        badopt = 0;
-        i = 0;
-        while (!badopt && argv[++i] != NULL) {
-                if (strcmp(argv[i], "-out") == 0) {
-                        if ((argv[i + 1] != NULL) && (outfile == NULL))
-                                outfile = argv[++i];
-                        else
-                                badopt = 1;
-                }
-#ifndef OPENSSL_NO_ENGINE
-                else if (strcmp(argv[i], "-engine") == 0) {
-                        if ((argv[i + 1] != NULL) && (engine == NULL))
-                                engine = argv[++i];
-                        else
-                                badopt = 1;
-                }
-#endif
-                else if (strcmp(argv[i], "-base64") == 0) {
-                        if (!base64)
-                                base64 = 1;
-                        else
-                                badopt = 1;
-                } else if (strcmp(argv[i], "-hex") == 0) {
-                        if (!hex)
-                                hex = 1;
-                        else
-                                badopt = 1;
-                } else if (isdigit((unsigned char) argv[i][0])) {
-                        if (num < 0) {
-                                r = sscanf(argv[i], "%d", &num);
-                                if (r == 0 || num < 0)
-                                        badopt = 1;
-                        } else
-                                badopt = 1;
-                } else
-                        badopt = 1;
+        if (options_parse(argc, argv, rand_options, &num_bytes) != 0) {
+                rand_usage();
+                return (1);
         }
 
-        if (hex && base64)
+        if (num_bytes != NULL) {
+                r = sscanf(num_bytes, "%d", &num);
+                if (r == 0 || num < 0)
+                        badopt = 1;
+        } else
                 badopt = 1;
 
-        if (num < 0)
+        if (rand_config.hex && rand_config.base64)
                 badopt = 1;
 
         if (badopt) {
-                BIO_printf(bio_err, "Usage: rand [options] num\n");
-                BIO_printf(bio_err, "where options are\n");
-                BIO_printf(bio_err, "-out file             - write to file\n");
-#ifndef OPENSSL_NO_ENGINE
-                BIO_printf(bio_err, "-engine e             - use engine e, possibly a hardware device.\n");
-#endif
-                BIO_printf(bio_err, "-base64               - base64 encode output\n");
-                BIO_printf(bio_err, "-hex                  - hex encode output\n");
+                rand_usage();
                 goto err;
         }
+
 #ifndef OPENSSL_NO_ENGINE
-        setup_engine(bio_err, engine, 0);
+        setup_engine(bio_err, rand_config.engine, 0);
 #endif
 
         out = BIO_new(BIO_s_file());
         if (out == NULL)
                 goto err;
-        if (outfile != NULL)
-                r = BIO_write_filename(out, outfile);
-        else {
+        if (rand_config.outfile != NULL)
+                r = BIO_write_filename(out, rand_config.outfile);
+        else
                 r = BIO_set_fp(out, stdout, BIO_NOCLOSE | BIO_FP_TEXT);
-        }
         if (r <= 0)
                 goto err;
-
-        if (base64) {
+        if (rand_config.base64) {
                 BIO *b64 = BIO_new(BIO_f_base64());
                 if (b64 == NULL)
                         goto err;
                 out = BIO_push(b64, out);
         }
+
         while (num > 0) {
                 unsigned char buf[4096];
                 int chunk;
 
                 chunk = num;
                 if (chunk > (int) sizeof(buf))
-                        chunk = sizeof buf;
+                        chunk = sizeof(buf);
                 r = RAND_bytes(buf, chunk);
                 if (r <= 0)
                         goto err;
-                if (!hex)
-                        BIO_write(out, buf, chunk);
-                else {
+                if (rand_config.hex) {
                         for (i = 0; i < chunk; i++)
                                 BIO_printf(out, "%02x", buf[i]);
-                }
+                } else
+                        BIO_write(out, buf, chunk);
                 num -= chunk;
         }
-        if (hex)
+
+        if (rand_config.hex)
                 BIO_puts(out, "\n");
         (void) BIO_flush(out);