Big apps cleanup (option-parsing, etc)

This is merges the old "rsalz-monolith" branch over to master.  The biggest
change is that option parsing switch from cascasding 'else if strcmp("-foo")'
to a utility routine and somethin akin to getopt.  Also, an error in the
command line no longer prints the full summary; use -help (or --help :)
for that.  There have been many other changes and code-cleanup, see
bullet list below.

Special thanks to Matt for the long and detailed code review.

TEMPORARY:
        For now, comment out CRYPTO_mem_leaks() at end of main

Tickets closed:
        RT3515: Use 3DES in pkcs12 if built with no-rc2
        RT1766: s_client -reconnect and -starttls broke
        RT2932: Catch write errors
        RT2604: port should be 'unsigned short'
        RT2983: total_bytes undeclared #ifdef RENEG
        RT1523: Add -nocert to fix output in x509 app
        RT3508: Remove unused variable introduced by b09eb24
        RT3511: doc fix; req default serial is random
        RT1325,2973: Add more extensions to c_rehash
        RT2119,3407: Updated to dgst.pod
        RT2379: Additional typo fix
        RT2693: Extra include of string.h
        RT2880: HFS is case-insensitive filenames
        RT3246: req command prints version number wrong

Other changes; incompatibilities marked with *:
        Add SCSV support
        Add -misalign to speed command
        Make dhparam, dsaparam, ecparam, x509 output C in proper style
        Make some internal ocsp.c functions void
        Only display cert usages with -help in verify
        Use global bio_err, remove "BIO*err" parameter from functions
        For filenames, - always means stdin (or stdout as appropriate)
        Add aliases for -des/aes "wrap" ciphers.
        *Remove support for IISSGC (server gated crypto)
        *The undocumented OCSP -header flag is now "-header name=value"
        *Documented the OCSP -header flag

Reviewed-by: Matt Caswell <matt@openssl.org>

1 files changed, 915 insertions, 0 deletions

diff --git a/apps/opt.c b/apps/opt.c
new file mode 100644
index 0000000000..3706739c03
--- /dev/null
+++ b/apps/opt.c
@@ -0,0 +1,915 @@
+/* ====================================================================
+ * Copyright (c) 2015 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ */
+
+/* #define COMPILE_STANDALONE_TEST_DRIVER  */
+#include "apps.h"
+#include <assert.h>
+#include <string.h>
+#if !defined(OPENSSL_SYS_MSDOS)
+# include OPENSSL_UNISTD
+#endif
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <ctype.h>
+#include <openssl/bio.h>
+
+#define MAX_OPT_HELP_WIDTH 30
+const char OPT_HELP_STR[] = "--";
+const char OPT_MORE_STR[] = "---";
+
+/* Our state */
+static char **argv;
+static int argc;
+static int opt_index;
+static char *arg;
+static char *flag;
+static char *dunno;
+static const OPTIONS *unknown;
+static const OPTIONS *opts;
+static char prog[40];
+
+/*
+ * Return the simple name of the program; removing various platform gunk.
+ */
+#if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_NETWARE)
+char *opt_progname(const char *argv0)
+{
+    int i;
+    int n;
+    const char *p;
+    char *q;
+
+    /* find the last '/', '\' or ':' */
+    for (p = argv0 + strlen(argv0); --p > argv0;)
+        if (*p == '/' || *p == '\\' || *p == ':') {
+            p++;
+            break;
+        }
+
+    /* Strip off trailing nonsense. */
+    n = strlen(p);
+    if (n > 4 &&
+        (strcmp(&p[n - 4], ".exe") == 0 || strcmp(&p[n - 4], ".EXE") == 0)
+        n -= 4;
+#if defined(OPENSSL_SYS_NETWARE)
+    if (n > 4 &&
+        (strcmp(&p[n - 4], ".nlm") == 0 || strcmp(&p[n - 4], ".NLM") == 0)
+        n -= 4;
+#endif
+
+    /* Copy over the name, in lowercase. */
+    if (n > sizeof prog - 1)
+        n = sizeof prog - 1;
+    for (q = prog, i = 0; i < n; i++, p++)
+        q++ = isupper(*p) ? tolower(*p) : *p;
+    *q = '\0';
+    return prog;
+}
+
+#elif defined(OPENSSL_SYS_VMS)
+
+char *opt_progname(const char *argv0)
+{
+    const char *p, *q;
+
+    /* Find last special charcter sys:[foo.bar]openssl */
+    for (p = argv0 + strlen(argv0); --p > argv0;)
+        if (*p == ':' || *p == ']' || *p == '>') {
+            p++;
+            break;
+        }
+
+    q = strrchr(p, '.');
+    strncpy(prog, p, sizeof prog - 1);
+    prog[sizeof prog - 1] = '\0';
+    if (q == NULL || q - p >= sizeof prog)
+        prog[q - p] = '\0';
+    return prog;
+}
+
+#else
+
+char *opt_progname(const char *argv0)
+{
+    const char *p;
+
+    /* Could use strchr, but this is like the ones above. */
+    for (p = argv0 + strlen(argv0); --p > argv0;)
+        if (*p == '/') {
+            p++;
+            break;
+        }
+    strncpy(prog, p, sizeof prog - 1);
+    prog[sizeof prog - 1] = '\0';
+    return prog;
+}
+#endif
+
+char *opt_getprog(void)
+{
+    return prog;
+}
+
+/* Set up the arg parsing. */
+char *opt_init(int ac, char **av, const OPTIONS *o)
+{
+    /* Store state. */
+    argc = ac;
+    argv = av;
+    opt_index = 1;
+    opts = o;
+    opt_progname(av[0]);
+    unknown = NULL;
+
+    for (; o->name; ++o) {
+        const OPTIONS *next;
+#ifndef NDEBUG
+        int i;
+#endif
+
+        if (o->name == OPT_HELP_STR || o->name == OPT_MORE_STR)
+            continue;
+#ifndef NDEBUG
+        i = o->valtype;
+
+        /* Make sure options are legit. */
+        assert(o->name[0] != '-');
+        assert(o->retval > 0);
+        assert(i == 0 || i == '-'
+               || i == 'n' || i == 'p' || i == 'u'
+               || i == 's' || i == '<' || i == '>' || i == '/'
+               || i == 'f' || i == 'F');
+
+        /* Make sure there are no duplicates. */
+        for (next = o; (++next)->name;) {
+            /*
+             * do allow aliases: assert(o->retval != next->retval);
+             */
+            assert(strcmp(o->name, next->name) != 0);
+        }
+#endif
+        if (o->name[0] == '\0') {
+            assert(unknown == NULL);
+            unknown = o;
+            assert(unknown->valtype == 0 || unknown->valtype == '-');
+        }
+    }
+    return prog;
+}
+
+static OPT_PAIR formats[] = {
+    {"PEM/DER", OPT_FMT_PEMDER},
+    {"pkcs12", OPT_FMT_PKCS12},
+    {"smime", OPT_FMT_SMIME},
+    {"engine", OPT_FMT_ENGINE},
+    {"msblob", OPT_FMT_MSBLOB},
+    {"netscape", OPT_FMT_NETSCAPE},
+    {"nss", OPT_FMT_NSS},
+    {"text", OPT_FMT_TEXT},
+    {"http", OPT_FMT_HTTP},
+    {"pvk", OPT_FMT_PVK},
+    {NULL}
+};
+
+/* Print an error message about a failed format parse. */
+int opt_format_error(const char *s, unsigned long flags)
+{
+    OPT_PAIR *ap;
+
+    if (flags == OPT_FMT_PEMDER)
+        BIO_printf(bio_err, "%s: Bad format \"%s\"; must be pem or der\n",
+                   prog, s);
+    else {
+        BIO_printf(bio_err, "%s: Bad format \"%s\"; must be one of:\n",
+                   prog, s);
+        for (ap = formats; ap->name; ap++)
+            if (flags & ap->retval)
+                BIO_printf(bio_err, "   %s\n", ap->name);
+    }
+    return 0;
+}
+
+/* Parse a format string, put it into *result; return 0 on failure, else 1. */
+int opt_format(const char *s, unsigned long flags, int *result)
+{
+    switch (*s) {
+    default:
+        return 0;
+    case 'D':
+    case 'd':
+        if ((flags & OPT_FMT_PEMDER) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_ASN1;
+        break;
+    case 'T':
+    case 't':
+        if ((flags & OPT_FMT_TEXT) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_TEXT;
+        break;
+    case 'N':
+    case 'n':
+        if (strcmp(s, "NSS") == 0 || strcmp(s, "nss") == 0) {
+            if ((flags & OPT_FMT_NSS) == 0)
+                return opt_format_error(s, flags);
+            *result = FORMAT_NSS;
+        } else {
+            if ((flags & OPT_FMT_NETSCAPE) == 0)
+                return opt_format_error(s, flags);
+            *result = FORMAT_NETSCAPE;
+        }
+        break;
+    case 'S':
+    case 's':
+        if ((flags & OPT_FMT_SMIME) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_SMIME;
+        break;
+    case 'M':
+    case 'm':
+        if ((flags & OPT_FMT_MSBLOB) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_MSBLOB;
+        break;
+    case 'E':
+    case 'e':
+        if ((flags & OPT_FMT_ENGINE) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_ENGINE;
+        break;
+    case 'H':
+    case 'h':
+        if ((flags & OPT_FMT_HTTP) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_HTTP;
+        break;
+    case '1':
+        if ((flags & OPT_FMT_PKCS12) == 0)
+            return opt_format_error(s, flags);
+        *result = FORMAT_PKCS12;
+        break;
+    case 'P':
+    case 'p':
+        if (s[1] == '\0' || strcmp(s, "PEM") == 0 || strcmp(s, "pem") == 0) {
+            if ((flags & OPT_FMT_PEMDER) == 0)
+                return opt_format_error(s, flags);
+            *result = FORMAT_PEM;
+        } else if (strcmp(s, "PVK") == 0 || strcmp(s, "pvk") == 0) {
+            if ((flags & OPT_FMT_PVK) == 0)
+                return opt_format_error(s, flags);
+            *result = FORMAT_PVK;
+        } else if (strcmp(s, "P12") == 0 || strcmp(s, "p12") == 0
+                   || strcmp(s, "PKCS12") == 0 || strcmp(s, "pkcs12") == 0) {
+            if ((flags & OPT_FMT_PKCS12) == 0)
+                return opt_format_error(s, flags);
+            *result = FORMAT_PKCS12;
+        } else
+            return 0;
+        break;
+    }
+    return 1;
+}
+
+/* Parse a cipher name, put it in *EVP_CIPHER; return 0 on failure, else 1. */
+int opt_cipher(const char *name, const EVP_CIPHER **cipherp)
+{
+    *cipherp = EVP_get_cipherbyname(name);
+    if (*cipherp)
+        return 1;
+    BIO_printf(bio_err, "%s: Unknown cipher %s\n", prog, name);
+    return 0;
+}
+
+/*
+ * Parse message digest name, put it in *EVP_MD; return 0 on failure, else 1.
+ */
+int opt_md(const char *name, const EVP_MD **mdp)
+{
+    *mdp = EVP_get_digestbyname(name);
+    if (*mdp)
+        return 1;
+    BIO_printf(bio_err, "%s: Unknown digest %s\n", prog, name);
+    return 0;
+}
+
+/* Look through a list of name/value pairs. */
+int opt_pair(const char *name, const OPT_PAIR* pairs, int *result)
+{
+    const OPT_PAIR *pp;
+
+    for (pp = pairs; pp->name; pp++)
+        if (strcmp(pp->name, name) == 0) {
+            *result = pp->retval;
+            return 1;
+        }
+    BIO_printf(bio_err, "%s: Value must be one of:\n", prog);
+    for (pp = pairs; pp->name; pp++)
+        BIO_printf(bio_err, "\t%s\n", pp->name);
+    return 0;
+}
+
+/* See if cp looks like a hex number, in case user left off the 0x */
+static int scanforhex(const char *cp)
+{
+    if (*cp == '0' && (cp[1] == 'x' || cp[1] == 'X'))
+        return 16;
+    for (; *cp; cp++)
+        /* Look for a hex digit that isn't a regular digit. */
+        if (isxdigit(*cp) && !isdigit(*cp))
+            return 16;
+    return 0;
+}
+
+/* Parse an int, put it into *result; return 0 on failure, else 1. */
+int opt_int(const char *value, int *result)
+{
+    const char *fmt = "%d";
+    int base = scanforhex(value);
+
+    if (base == 16)
+        fmt = "%x";
+    else if (*value == '0')
+        fmt = "%o";
+    if (sscanf(value, fmt, result) != 1) {
+        BIO_printf(bio_err, "%s: Can't parse \"%s\" as a number\n",
+                   prog, value);
+        return 0;
+    }
+    return 1;
+}
+
+/* Parse a long, put it into *result; return 0 on failure, else 1. */
+int opt_long(const char *value, long *result)
+{
+    char *endptr;
+    int base = scanforhex(value);
+
+    *result = strtol(value, &endptr, base);
+    if (*endptr) {
+        BIO_printf(bio_err,
+                   "%s: Bad char %c in number %s\n", prog, *endptr, value);
+        return 0;
+    }
+    return 1;
+}
+
+/*
+ * Parse an unsigned long, put it into *result; return 0 on failure, else 1.
+ */
+int opt_ulong(const char *value, unsigned long *result)
+{
+    char *endptr;
+    int base = scanforhex(value);
+
+    *result = strtoul(value, &endptr, base);
+    if (*endptr) {
+        BIO_printf(bio_err,
+                   "%s: Bad char %c in number %s\n", prog, *endptr, value);
+        return 0;
+    }
+    return 1;
+}
+
+/*
+ * We pass opt as an int but cast it to "enum range" so that all the
+ * items in the OPT_V_ENUM enumeration are caught; this makes -Wswitch
+ * in gcc do the right thing.
+ */
+enum range { OPT_V_ENUM };
+
+int opt_verify(int opt, X509_VERIFY_PARAM *vpm)
+{
+    unsigned long ul;
+    int i;
+    ASN1_OBJECT *otmp;
+    X509_PURPOSE *xptmp;
+    const X509_VERIFY_PARAM *vtmp;
+
+    assert(vpm != NULL);
+    assert(opt > OPT_V__FIRST);
+    assert(opt < OPT_V__LAST);
+
+    switch ((enum range)opt) {
+    case OPT_V__FIRST:
+    case OPT_V__LAST:
+        return 0;
+    case OPT_V_POLICY:
+        otmp = OBJ_txt2obj(opt_arg(), 0);
+        if (otmp == NULL) {
+            BIO_printf(bio_err, "%s: Invalid Policy %s\n", prog, opt_arg());
+            return 0;
+        }
+        X509_VERIFY_PARAM_add0_policy(vpm, otmp);
+        break;
+    case OPT_V_PURPOSE:
+        i = X509_PURPOSE_get_by_sname(opt_arg());
+        if (i < 0) {
+            BIO_printf(bio_err, "%s: Invalid purpose %s\n", prog, opt_arg());
+            return 0;
+        }
+        xptmp = X509_PURPOSE_get0(i);
+        i = X509_PURPOSE_get_id(xptmp);
+        X509_VERIFY_PARAM_set_purpose(vpm, i);
+        break;
+    case OPT_V_VERIFY_NAME:
+        vtmp = X509_VERIFY_PARAM_lookup(opt_arg());
+        if (vtmp == NULL) {
+            BIO_printf(bio_err, "%s: Invalid verify name %s\n",
+                       prog, opt_arg());
+            return 0;
+        }
+        X509_VERIFY_PARAM_set1(vpm, vtmp);
+        break;
+    case OPT_V_VERIFY_DEPTH:
+        i = atoi(opt_arg());
+        if (i >= 0)
+            X509_VERIFY_PARAM_set_depth(vpm, i);
+        break;
+    case OPT_V_ATTIME:
+        opt_ulong(opt_arg(), &ul);
+        if (ul)
+            X509_VERIFY_PARAM_set_time(vpm, (time_t)ul);
+        break;
+    case OPT_V_VERIFY_HOSTNAME:
+        if (!X509_VERIFY_PARAM_set1_host(vpm, opt_arg(), 0))
+            return 0;
+        break;
+    case OPT_V_VERIFY_EMAIL:
+        if (!X509_VERIFY_PARAM_set1_email(vpm, opt_arg(), 0))
+            return 0;
+        break;
+    case OPT_V_VERIFY_IP:
+        if (!X509_VERIFY_PARAM_set1_ip_asc(vpm, opt_arg()))
+            return 0;
+        break;
+    case OPT_V_IGNORE_CRITICAL:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_IGNORE_CRITICAL);
+        break;
+    case OPT_V_ISSUER_CHECKS:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_CB_ISSUER_CHECK);
+        break;
+    case OPT_V_CRL_CHECK:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_CRL_CHECK);
+        break;
+    case OPT_V_CRL_CHECK_ALL:
+        X509_VERIFY_PARAM_set_flags(vpm,
+                                    X509_V_FLAG_CRL_CHECK |
+                                    X509_V_FLAG_CRL_CHECK_ALL);
+        break;
+    case OPT_V_POLICY_CHECK:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_POLICY_CHECK);
+        break;
+    case OPT_V_EXPLICIT_POLICY:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_EXPLICIT_POLICY);
+        break;
+    case OPT_V_INHIBIT_ANY:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_INHIBIT_ANY);
+        break;
+    case OPT_V_INHIBIT_MAP:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_INHIBIT_MAP);
+        break;
+    case OPT_V_X509_STRICT:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_X509_STRICT);
+        break;
+    case OPT_V_EXTENDED_CRL:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_EXTENDED_CRL_SUPPORT);
+        break;
+    case OPT_V_USE_DELTAS:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_USE_DELTAS);
+        break;
+    case OPT_V_POLICY_PRINT:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_NOTIFY_POLICY);
+        break;
+    case OPT_V_CHECK_SS_SIG:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_CHECK_SS_SIGNATURE);
+        break;
+    case OPT_V_TRUSTED_FIRST:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_TRUSTED_FIRST);
+        break;
+    case OPT_V_SUITEB_128_ONLY:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_SUITEB_128_LOS_ONLY);
+        break;
+    case OPT_V_SUITEB_128:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_SUITEB_128_LOS);
+        break;
+    case OPT_V_SUITEB_192:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_SUITEB_192_LOS);
+        break;
+    case OPT_V_PARTIAL_CHAIN:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_PARTIAL_CHAIN);
+        break;
+    case OPT_V_NO_ALT_CHAINS:
+        X509_VERIFY_PARAM_set_flags(vpm, X509_V_FLAG_NO_ALT_CHAINS);
+    }
+    return 1;
+
+}
+
+/*
+ * Parse the next flag (and value if specified), return 0 if done, -1 on
+ * error, otherwise the flag's retval.
+ */
+int opt_next(void)
+{
+    char *p;
+    char *endptr;
+    const OPTIONS *o;
+    int dummy;
+    int base;
+    long val;
+
+    /* Look at current arg; at end of the list? */
+    arg = NULL;
+    p = argv[opt_index];
+    if (p == NULL)
+        return 0;
+
+    /* If word doesn't start with a -, we're done. */
+    if (*p != '-')
+        return 0;
+
+    /* Hit "--" ? We're done. */
+    opt_index++;
+    if (strcmp(p, "--") == 0)
+        return 0;
+
+    /* Allow -nnn and --nnn */
+    if (*++p == '-')
+        p++;
+    flag = p - 1;
+
+    /* If we have --flag=foo, snip it off */
+    if ((arg = strchr(p, '=')) != NULL)
+        *arg++ = '\0';
+    for (o = opts; o->name; ++o) {
+        /* If not this option, move on to the next one. */
+        if (strcmp(p, o->name) != 0)
+            continue;
+
+        /* If it doesn't take a value, make sure none was given. */
+        if (o->valtype == 0 || o->valtype == '-') {
+            if (arg) {
+                BIO_printf(bio_err,
+                           "%s: Option -%s does not take a value\n", prog, p);
+                return -1;
+            }
+            return o->retval;
+        }
+
+        /* Want a value; get the next param if =foo not used. */
+        if (arg == NULL) {
+            if (argv[opt_index] == NULL) {
+                BIO_printf(bio_err,
+                           "%s: Option -%s needs a value\n", prog, o->name);
+                return -1;
+            }
+            arg = argv[opt_index++];
+        }
+
+        /* Syntax-check value. */
+        /*
+         * Do some basic syntax-checking on the value.  These tests aren't
+         * perfect (ignore range overflow) but they catch common failures.
+         */
+        switch (o->valtype) {
+        default:
+        case 's':
+            /* Just a string. */
+            break;
+        case '/':
+            if (app_isdir(arg) >= 0)
+                break;
+            BIO_printf(bio_err, "%s: Not a directory: %s\n", prog, arg);
+            return -1;
+        case '<':
+            /* Input file. */
+            if (strcmp(arg, "-") == 0 || app_access(arg, R_OK) >= 0)
+                break;
+            BIO_printf(bio_err,
+                       "%s: Cannot open input file %s, %s\n",
+                       prog, arg, strerror(errno));
+            return -1;
+        case '>':
+            /* Output file. */
+            if (strcmp(arg, "-") == 0 || app_access(arg, W_OK) >= 0 || errno == ENOENT)
+                break;
+            BIO_printf(bio_err,
+                       "%s: Cannot open output file %s, %s\n",
+                       prog, arg, strerror(errno));
+            return -1;
+        case 'p':
+        case 'n':
+            base = scanforhex(arg);
+            val = strtol(arg, &endptr, base);
+            if (*endptr == '\0') {
+                if (o->valtype == 'p' && val <= 0) {
+                    BIO_printf(bio_err,
+                               "%s: Non-positive number \"%s\" for -%s\n",
+                               prog, arg, o->name);
+                    return -1;
+                }
+                break;
+            }
+            BIO_printf(bio_err,
+                       "%s: Invalid number \"%s\" for -%s\n",
+                       prog, arg, o->name);
+            return -1;
+        case 'u':
+            base = scanforhex(arg);
+            strtoul(arg, &endptr, base);
+            if (*endptr == '\0')
+                break;
+            BIO_printf(bio_err,
+                       "%s: Invalid number \"%s\" for -%s\n",
+                       prog, arg, o->name);
+            return -1;
+        case 'f':
+        case 'F':
+            if (opt_format(arg,
+                           o->valtype == 'F' ? OPT_FMT_PEMDER
+                           : OPT_FMT_ANY, &dummy))
+                break;
+            BIO_printf(bio_err,
+                       "%s: Invalid format \"%s\" for -%s\n",
+                       prog, arg, o->name);
+            return -1;
+        }
+
+        /* Return the flag value. */
+        return o->retval;
+    }
+    if (unknown != NULL) {
+        dunno = p;
+        return unknown->retval;
+    }
+    BIO_printf(bio_err, "%s: Option unknown option -%s\n", prog, p);
+    return -1;
+}
+
+/* Return the most recent flag parameter. */
+char *opt_arg(void)
+{
+    return arg;
+}
+
+/* Return the most recent flag. */
+char *opt_flag(void)
+{
+    return flag;
+}
+
+/* Return the unknown option. */
+char *opt_unknown(void)
+{
+    return dunno;
+}
+
+/* Return the rest of the arguments after parsing flags. */
+char **opt_rest(void)
+{
+    return &argv[opt_index];
+}
+
+/* How many items in remaining args? */
+int opt_num_rest(void)
+{
+    int i = 0;
+    char **pp;
+
+    for (pp = opt_rest(); *pp; pp++, i++)
+        continue;
+    return i;
+}
+
+/* Return a string describing the parameter type. */
+static const char *valtype2param(const OPTIONS *o)
+{
+    switch (o->valtype) {
+    case '-':
+        return "";
+    case 's':
+        return "val";
+    case '/':
+        return "dir";
+    case '<':
+        return "infile";
+    case '>':
+        return "outfile";
+    case 'p':
+        return "pnum";
+    case 'n':
+        return "num";
+    case 'u':
+        return "unum";
+    case 'F':
+        return "der/pem";
+    case 'f':
+        return "format";
+    }
+    return "parm";
+}
+
+void opt_help(const OPTIONS *list)
+{
+    const OPTIONS *o;
+    int i;
+    int standard_prolog;
+    int width = 5;
+    char start[80 + 1];
+    char *p;
+    const char *help;
+
+    /* Starts with its own help message? */
+    standard_prolog = list[0].name != OPT_HELP_STR;
+
+    /* Find the widest help. */
+    for (o = list; o->name; o++) {
+        if (o->name == OPT_MORE_STR)
+            continue;
+        i = 2 + (int)strlen(o->name);
+        if (o->valtype != '-')
+            i += 1 + strlen(valtype2param(o));
+        if (i < MAX_OPT_HELP_WIDTH && i > width)
+            width = i;
+        assert(i < (int)sizeof start);
+    }
+
+    if (standard_prolog)
+        BIO_printf(bio_err, "Usage: %s [options]\nValid options are:\n",
+                   prog);
+
+    /* Now let's print. */
+    for (o = list; o->name; o++) {
+        help = o->helpstr ? o->helpstr : "(No additional info)";
+        if (o->name == OPT_HELP_STR) {
+            BIO_printf(bio_err, help, prog);
+            continue;
+        }
+
+        /* Pad out prefix */
+        memset(start, ' ', sizeof start - 1);
+        start[sizeof start - 1] = '\0';
+
+        if (o->name == OPT_MORE_STR) {
+            /* Continuation of previous line; padd and print. */
+            start[width] = '\0';
+            BIO_printf(bio_err, "%s  %s\n", start, help);
+            continue;
+        }
+
+        /* Build up the "-flag [param]" part. */
+        p = start;
+        *p++ = ' ';
+        *p++ = '-';
+        if (o->name[0])
+            p += strlen(strcpy(p, o->name));
+        else
+            *p++ = '*';
+        if (o->valtype != '-') {
+            *p++ = ' ';
+            p += strlen(strcpy(p, valtype2param(o)));
+        }
+        *p = ' ';
+        if ((int)(p - start) >= MAX_OPT_HELP_WIDTH) {
+            *p = '\0';
+            BIO_printf(bio_err, "%s\n", start);
+            memset(start, ' ', sizeof start);
+        }
+        start[width] = '\0';
+        BIO_printf(bio_err, "%s  %s\n", start, help);
+    }
+}
+
+#ifdef COMPILE_STANDALONE_TEST_DRIVER
+# include <sys/stat.h>
+
+typedef enum OPTION_choice {
+    OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
+    OPT_IN, OPT_INFORM, OPT_OUT, OPT_COUNT, OPT_U, OPT_FLAG,
+    OPT_STR, OPT_NOTUSED
+} OPTION_CHOICE;
+
+static OPTIONS options[] = {
+    {OPT_HELP_STR, 1, '-', "Usage: %s flags\n"},
+    {OPT_HELP_STR, 1, '-', "Valid options are:\n"},
+    {"help", OPT_HELP, '-', "Display this summary"},
+    {"in", OPT_IN, '<', "input file"},
+    {OPT_MORE_STR, 1, '-', "more detail about input"},
+    {"inform", OPT_INFORM, 'f', "input file format; defaults to pem"},
+    {"out", OPT_OUT, '>', "output file"},
+    {"count", OPT_COUNT, 'p', "a counter greater than zero"},
+    {"u", OPT_U, 'u', "an unsigned number"},
+    {"flag", OPT_FLAG, 0, "just some flag"},
+    {"str", OPT_STR, 's', "the magic word"},
+    {"areallyverylongoption", OPT_HELP, '-', "long way for help"},
+    {NULL}
+};
+
+BIO *bio_err;
+
+int app_isdir(const char *name)
+{
+    struct stat sb;
+
+    return name != NULL && stat(name, &sb) >= 0 && S_ISDIR(sb.st_mode);
+}
+
+int main(int ac, char **av)
+{
+    OPTION_CHOICE o;
+    char **rest;
+    char *prog;
+
+    bio_err = BIO_new_fp(stderr, BIO_NOCLOSE | BIO_FP_TEXT);
+
+    prog = opt_init(ac, av, options);
+    while ((o = opt_next()) != OPT_EOF) {
+        switch (c) {
+        case OPT_NOTUSED:
+        case OPT_EOF:
+        case OPT_ERR:
+            printf("%s: Usage error; try -help.\n", prog);
+            return 1;
+        case OPT_HELP:
+            opt_help(options);
+            return 0;
+        case OPT_IN:
+            printf("in %s\n", opt_arg());
+            break;
+        case OPT_INFORM:
+            printf("inform %s\n", opt_arg());
+            break;
+        case OPT_OUT:
+            printf("out %s\n", opt_arg());
+            break;
+        case OPT_COUNT:
+            printf("count %s\n", opt_arg());
+            break;
+        case OPT_U:
+            printf("u %s\n", opt_arg());
+            break;
+        case OPT_FLAG:
+            printf("flag\n");
+            break;
+        case OPT_STR:
+            printf("str %s\n", opt_arg());
+            break;
+        }
+    }
+    argc = opt_num_rest();
+    argv = opt_rest();
+
+    printf("args = %d\n", argc);
+    if (argc)
+        while (*argv)
+            printf("  %s\n", *argv++);
+    return 0;
+}
+#endif