On Fri, May 19, 2017 at 12:32:16AM -0500, Matthew Martin wrote:
> ikectl errors in a number of situations where shell special characters
> are used. For example:
> 
> % doas ikectl ca test create password \'
> [...]
> subject=/C=DE/ST=Lower Saxony/L=Hanover/O=OpenBSD/OU=iked/CN=VPN 
> CA/[email protected]
> Getting Private key
> sh: no closing quote
> 
> This is because it uses system(3) in various places to run openssl, tar,
> and zip. Take the hint from the system(3) man page, and write a small
> function that does the fork and exec bypassing sh.
> 
> Keep in mind while reviewing ca->batch was either "" or "-batch " and is
> now either "" or "-batch".
> 
> - Matthew Martin

This would be simpler if the 'run' style function just took a NULL
terminated array.  Closer to how other things work and could then
be passed directly to an exec call.

> 
> 
> 
> diff --git ikeca.c ikeca.c
> index cee6623a30f..69ca076407b 100644
> --- ikeca.c
> +++ ikeca.c
> @@ -24,6 +24,7 @@
>  #include <errno.h>
>  #include <string.h>
>  #include <stdlib.h>
> +#include <sys/wait.h>
>  #include <pwd.h>
>  #include <fcntl.h>
>  #include <fts.h>
> @@ -68,7 +69,7 @@ struct ca {
>       char             serial[PATH_MAX];
>       char             sslcnf[PATH_MAX];
>       char             extcnf[PATH_MAX];
> -     char             batch[PATH_MAX];
> +     char             batch[sizeof("-batch")];
>       char            *caname;
>  };
>  
> @@ -117,6 +118,7 @@ void               ca_setenv(const char *, const char *);
>  void          ca_clrenv(void);
>  void          ca_setcnf(struct ca *, const char *);
>  void          ca_create_index(struct ca *);
> +int static    run(int, ...);
>  
>  /* util.c */
>  int           expand_string(char *, size_t, const char *, const char *);
> @@ -131,7 +133,6 @@ int
>  ca_key_create(struct ca *ca, char *keyname)
>  {
>       struct stat              st;
> -     char                     cmd[PATH_MAX * 2];
>       char                     path[PATH_MAX];
>  
>       snprintf(path, sizeof(path), "%s/private/%s.key", ca->sslpath, keyname);
> @@ -141,10 +142,7 @@ ca_key_create(struct ca *ca, char *keyname)
>               return (0);
>       }
>  
> -     snprintf(cmd, sizeof(cmd),
> -         "%s genrsa -out %s 2048",
> -         PATH_OPENSSL, path);
> -     system(cmd);
> +     run(5, PATH_OPENSSL, "genrsa", "-out", path, "2048");
>       chmod(path, 0600);
>  
>       return (0);
> @@ -201,9 +199,9 @@ ca_delkey(struct ca *ca, char *keyname)
>  int
>  ca_request(struct ca *ca, char *keyname, int type)
>  {
> -     char            cmd[PATH_MAX * 2];
>       char            hostname[HOST_NAME_MAX+1];
>       char            name[128];
> +     char            key[PATH_MAX];
>       char            path[PATH_MAX];
>  
>       ca_setenv("$ENV::CERT_CN", keyname);
> @@ -227,13 +225,11 @@ ca_request(struct ca *ca, char *keyname, int type)
>  
>       ca_setcnf(ca, keyname);
>  
> +     snprintf(key, sizeof(key), "%s/private/%s.key",  ca->sslpath, keyname);
>       snprintf(path, sizeof(path), "%s/private/%s.csr", ca->sslpath, keyname);
> -     snprintf(cmd, sizeof(cmd), "%s req %s-new"
> -         " -key %s/private/%s.key -out %s -config %s",
> -         PATH_OPENSSL, ca->batch, ca->sslpath, keyname,
> -         path, ca->sslcnf);
>  
> -     system(cmd);
> +     run(10, PATH_OPENSSL, "req", ca->batch, "-new", "-key", key,
> +         "-out", path, "-config", ca->sslcnf);
>       chmod(path, 0600);
>  
>       return (0);
> @@ -242,7 +238,11 @@ ca_request(struct ca *ca, char *keyname, int type)
>  int
>  ca_sign(struct ca *ca, char *keyname, int type)
>  {
> -     char            cmd[PATH_MAX * 2];
> +     char            keyfile[PATH_MAX];
> +     char            cert[PATH_MAX];
> +     char            out[PATH_MAX];
> +     char            in[PATH_MAX];
> +     char            passfile[PATH_MAX+5];
>       const char      *extensions = NULL;
>  
>       if (type == HOST_IPADDR) {
> @@ -259,19 +259,16 @@ ca_sign(struct ca *ca, char *keyname, int type)
>       ca_setenv("$ENV::CASERIAL", ca->serial);
>       ca_setcnf(ca, keyname);
>  
> -     snprintf(cmd, sizeof(cmd),
> -         "%s ca -config %s -keyfile %s/private/ca.key"
> -         " -cert %s/ca.crt"
> -         " -extfile %s -extensions %s -out %s/%s.crt"
> -         " -in %s/private/%s.csr"
> -         " -passin file:%s -outdir %s -batch",
> -         PATH_OPENSSL, ca->sslcnf, ca->sslpath,
> -         ca->sslpath,
> -         ca->extcnf, extensions, ca->sslpath, keyname,
> -         ca->sslpath, keyname,
> -         ca->passfile, ca->sslpath);
> +     snprintf(keyfile, sizeof(keyfile), "%s/private/ca.key",  ca->sslpath);
> +     snprintf(cert, sizeof(cert), "%s/ca.crt", ca->sslpath);
> +     snprintf(out, sizeof(out), "%s/%s.crt", ca->sslpath, keyname);
> +     snprintf(in, sizeof(in), "%s/private/%s.csr", ca->sslpath, keyname);
> +     snprintf(passfile, sizeof(passfile), "file:%s", ca->passfile);
>  
> -     system(cmd);
> +     run(21, PATH_OPENSSL, "ca", "-config", ca->sslcnf, "-keyfile", keyfile,
> +         "-cert", cert, "-extfile", ca->extcnf, "-extensions", extensions,
> +         "-out", out, "-in", in, "-passin", passfile,
> +         "-outdir", ca->sslpath, "-batch");
>  
>       return (0);
>  }
> @@ -314,9 +311,9 @@ int
>  ca_key_install(struct ca *ca, char *keyname, char *dir)
>  {
>       struct stat      st;
> -     char             cmd[PATH_MAX * 2];
>       char             src[PATH_MAX];
>       char             dst[PATH_MAX];
> +     char             out[PATH_MAX];
>       char            *p = NULL;
>  
>       snprintf(src, sizeof(src), "%s/private/%s.key", ca->sslpath, keyname);
> @@ -336,9 +333,9 @@ ca_key_install(struct ca *ca, char *keyname, char *dir)
>       snprintf(dst, sizeof(dst), "%s/private/local.key", dir);
>       fcopy(src, dst, 0600);
>  
> -     snprintf(cmd, sizeof(cmd), "%s rsa -out %s/local.pub"
> -         " -in %s/private/local.key -pubout", PATH_OPENSSL, dir, dir);
> -     system(cmd);
> +     snprintf(out, sizeof(out), "%s/local.pub", dir);
> +
> +     run(7, PATH_OPENSSL, "rsa", "-out", out, "-in", dst, "-pubout");
>  
>       free(p);
>  
> @@ -406,37 +403,33 @@ ca_newpass(char *passfile, char *password)
>  int
>  ca_create(struct ca *ca)
>  {
> -     char                     cmd[PATH_MAX * 2];
> -     char                     path[PATH_MAX];
> +     char                     key[PATH_MAX];
> +     char                     passfile[PATH_MAX+5];
> +     char                     csr[PATH_MAX];
> +     char                     crt[PATH_MAX];
>  
>       ca_clrenv();
>  
> -     snprintf(path, sizeof(path), "%s/private/ca.key", ca->sslpath);
> -     snprintf(cmd, sizeof(cmd), "%s genrsa -aes256 -out"
> -         " %s -passout file:%s 2048", PATH_OPENSSL,
> -         path, ca->passfile);
> -     system(cmd);
> -     chmod(path, 0600);
> +     snprintf(key, sizeof(key), "%s/private/ca.key", ca->sslpath);
> +     snprintf(passfile, sizeof(passfile), "file:%s", ca->passfile);
> +
> +     run(8, PATH_OPENSSL, "genrsa", "-aes256", "-out", key,
> +         "-passout", passfile, "2048");
> +     chmod(key, 0600);
>  
>       ca_setenv("$ENV::CERT_CN", "VPN CA");
>       ca_setenv("$ENV::REQ_EXT", "x509v3_CA");
>       ca_setcnf(ca, "ca");
>  
> -     snprintf(path, sizeof(path), "%s/private/ca.csr", ca->sslpath);
> -     snprintf(cmd, sizeof(cmd), "%s req %s-new"
> -         " -key %s/private/ca.key"
> -         " -config %s -out %s -passin file:%s", PATH_OPENSSL,
> -         ca->batch, ca->sslpath, ca->sslcnf, path, ca->passfile);
> -     system(cmd);
> -     chmod(path, 0600);
> +     snprintf(csr, sizeof(csr), "%s/private/ca.csr", ca->sslpath);
> +     run(12, PATH_OPENSSL, "req", ca->batch, "-new", "-key", key,
> +         "-config", ca->sslcnf, "-out", csr, "-passin", passfile);
> +     chmod(csr, 0600);
>  
> -     snprintf(cmd, sizeof(cmd), "%s x509 -req -days 365"
> -         " -in %s/private/ca.csr -signkey %s/private/ca.key"
> -         " -sha256"
> -         " -extfile %s -extensions x509v3_CA -out %s/ca.crt -passin file:%s",
> -         PATH_OPENSSL, ca->sslpath, ca->sslpath, ca->extcnf, ca->sslpath,
> -         ca->passfile);
> -     system(cmd);
> +     snprintf(crt, sizeof(crt), "%s/ca.crt", ca->sslpath);
> +     run(18, PATH_OPENSSL, "x509", "-req", "-days", "365", "-in", csr,
> +         "-signkey", key, "-sha256", "-extfile", ca->extcnf,
> +         "-extensions", "x509v3_CA", "-out", crt, "-passin", passfile);
>  
>       /* Create the CRL revocation list */
>       ca_revoke(ca, NULL);
> @@ -486,7 +479,6 @@ ca_show_certs(struct ca *ca, char *name)
>  {
>       DIR             *dir;
>       struct dirent   *de;
> -     char             cmd[PATH_MAX * 2];
>       char             path[PATH_MAX];
>       char            *p;
>       struct stat      st;
> @@ -496,9 +488,7 @@ ca_show_certs(struct ca *ca, char *name)
>                   ca->sslpath, name);
>               if (stat(path, &st) != 0)
>                       err(1, "could not open file %s.crt", name);
> -             snprintf(cmd, sizeof(cmd), "%s x509 -text"
> -                 " -in %s", PATH_OPENSSL, path);
> -             system(cmd);
> +             run(5, PATH_OPENSSL, "x509", "-text", "-in", path);
>               printf("\n");
>               return (0);
>       }
> @@ -513,10 +503,8 @@ ca_show_certs(struct ca *ca, char *name)
>                               continue;
>                       snprintf(path, sizeof(path), "%s/%s", ca->sslpath,
>                           de->d_name);
> -                     snprintf(cmd, sizeof(cmd), "%s x509 -subject"
> -                         " -fingerprint -dates -noout -in %s",
> -                         PATH_OPENSSL, path);
> -                     system(cmd);
> +                     run(8, PATH_OPENSSL, "x509", "-subject", "-fingerprint",
> +                         "-dates", "-noout", "-in", path);
>                       printf("\n");
>               }
>       }
> @@ -650,10 +638,16 @@ ca_export(struct ca *ca, char *keyname, char *myname, 
> char *password)
>       struct stat      st;
>       char            *pass;
>       char             prev[_PASSWORD_LEN + 1];
> -     char             cmd[PATH_MAX * 2];
> +     char             passenv[_PASSWORD_LEN + 8];
>       char             oname[PATH_MAX];
>       char             src[PATH_MAX];
>       char             dst[PATH_MAX];
> +     char             cacrt[PATH_MAX];
> +     char             key[PATH_MAX];
> +     char             crt[PATH_MAX];
> +     char             pfx[PATH_MAX];
> +     char             capfx[PATH_MAX];
> +     char             passfile[PATH_MAX];
>       char            *p;
>       char             tpl[] = "/tmp/ikectl.XXXXXXXXXX";
>       unsigned int     i;
> @@ -671,7 +665,7 @@ ca_export(struct ca *ca, char *keyname, char *myname, 
> char *password)
>               *p = '_';
>  
>       if (password != NULL)
> -             pass = password;
> +             snprintf(passenv, sizeof(passenv), "EXPASS=%s", password);
>       else {
>               pass = getpass("Export passphrase:");
>               if (pass == NULL || *pass == '\0')
> @@ -681,24 +675,30 @@ ca_export(struct ca *ca, char *keyname, char *myname, 
> char *password)
>               pass = getpass("Retype export passphrase:");
>               if (pass == NULL || strcmp(prev, pass) != 0)
>                       errx(1, "passphrase does not match!");
> +
> +             snprintf(passenv, sizeof(passenv), "EXPASS=%s", pass);
>       }
>  
> +     snprintf(cacrt, sizeof(cacrt), "%s/ca.crt", ca->sslpath);
> +     snprintf(key, sizeof(key), "%s/private/%s.key", ca->sslpath, keyname);
> +     snprintf(crt, sizeof(crt), "%s/%s.crt", ca->sslpath, keyname);
> +     snprintf(pfx, sizeof(pfx), "%s/private/%s.pfx", ca->sslpath, oname);
> +     snprintf(capfx, sizeof(capfx), "%s/ca.pfx", ca->sslpath);
> +     snprintf(passfile, sizeof(passfile), "file:%s", ca->passfile);
> +
> +     putenv(passenv);
>       if (keyname != NULL) {
> -             snprintf(cmd, sizeof(cmd), "env EXPASS=%s %s pkcs12 -export"
> -                 " -name %s -CAfile %s/ca.crt -inkey %s/private/%s.key"
> -                 " -in %s/%s.crt -out %s/private/%s.pfx -passout env:EXPASS"
> -                 " -passin file:%s", pass, PATH_OPENSSL, keyname,
> -                 ca->sslpath, ca->sslpath, keyname, ca->sslpath, keyname,
> -                 ca->sslpath, oname, ca->passfile);
> -             system(cmd);
> -     }
> -
> -     snprintf(cmd, sizeof(cmd), "env EXPASS=%s %s pkcs12 -export"
> -         " -caname '%s' -name '%s' -cacerts -nokeys"
> -         " -in %s/ca.crt -out %s/ca.pfx -passout env:EXPASS -passin file:%s",
> -         pass, PATH_OPENSSL, ca->caname, ca->caname, ca->sslpath,
> -         ca->sslpath, ca->passfile);
> -     system(cmd);
> +             run(17, PATH_OPENSSL, "pkcs12", "-export", "-name", keyname,
> +                 "-CAfile", cacrt, "-inkey", key, "-in", crt, "-out", pfx,
> +                 "-passout", "env:EXPASS", "-passin", passfile);
> +     }
> +
> +     run(17, PATH_OPENSSL, "pkcs12", "-export", "-caname", ca->caname,
> +         "-name", ca->caname, "-cacerts", "-nokeys", "-in", cacrt,
> +         "-out", capfx, "-passout", "env:EXPASS", "-passin", passfile);
> +
> +     unsetenv("EXPASS");
> +     explicit_bzero(passenv, sizeof(passenv));
>  
>       if ((p = mkdtemp(tpl)) == NULL)
>               err(1, "could not create temp dir");
> @@ -753,21 +753,18 @@ ca_export(struct ca *ca, char *keyname, char *myname, 
> char *password)
>               snprintf(dst, sizeof(dst), "%s/certs/%s.crt", p, keyname);
>               fcopy(src, dst, 0644);
>  
> -             snprintf(cmd, sizeof(cmd), "%s rsa -out %s/local.pub"
> -                 " -in %s/private/%s.key -pubout", PATH_OPENSSL, p,
> -                 ca->sslpath, keyname);
> -             system(cmd);
> +             snprintf(src, sizeof(src), "%s/private/%s.key", ca->sslpath,
> +                 keyname);
> +             snprintf(dst, sizeof(dst), "%s/local.pub", p);
> +             run(7, PATH_OPENSSL, "rsa", "-out", dst, "-in", src, "-pubout");
>       }
>  
>       if (stat(PATH_TAR, &st) == 0) {
> +             snprintf(src, sizeof(src), "%s.tgz", oname);
>               if (keyname == NULL)
> -                     snprintf(cmd, sizeof(cmd), "%s -zcf %s.tgz -C %s .",
> -                         PATH_TAR, oname, ca->sslpath);
> +                     run(6, PATH_TAR, "-zcf", src, "-C", ca->sslpath, ".");
>               else
> -                     snprintf(cmd, sizeof(cmd), "%s -zcf %s.tgz -C %s .",
> -                         PATH_TAR, oname, p);
> -             system(cmd);
> -             snprintf(src, sizeof(src), "%s.tgz", oname);
> +                     run(6, PATH_TAR, "-zcf", src, "-C", p, ".");
>               if (realpath(src, dst) != NULL)
>                       printf("exported files in %s\n", dst);
>       }
> @@ -796,8 +793,7 @@ ca_export(struct ca *ca, char *keyname, char *myname, 
> char *password)
>                       err(1, "could not change %s", dst);
>  
>               snprintf(dst, sizeof(dst), "%s/%s.zip", src, oname);
> -             snprintf(cmd, sizeof(cmd), "%s -qr %s .", PATH_ZIP, dst);
> -             system(cmd);
> +             run(4, PATH_ZIP, "-qr", dst, ".");
>               printf("exported files in %s\n", dst);
>  
>               if (chdir(src) == -1)
> @@ -877,8 +873,9 @@ int
>  ca_revoke(struct ca *ca, char *keyname)
>  {
>       struct stat      st;
> -     char             cmd[PATH_MAX * 2];
>       char             path[PATH_MAX];
> +     char             cakey[PATH_MAX];
> +     char             cacrt[PATH_MAX];
>       char            *pass;
>       size_t           len;
>  
> @@ -902,27 +899,20 @@ ca_revoke(struct ca *ca, char *keyname)
>       ca_setenv("$ENV::CASERIAL", ca->serial);
>       ca_setcnf(ca, "ca-revoke");
>  
> +     snprintf(cakey, sizeof(cakey), "%s/private/ca.key", ca->sslpath);
> +     snprintf(cacrt, sizeof(cacrt), "%s/ca.crt", ca->sslpath);
> +
>       if (keyname) {
> -             snprintf(cmd, sizeof(cmd),
> -                 "%s ca %s-config %s -keyfile %s/private/ca.key"
> -                 " -key %s"
> -                 " -cert %s/ca.crt"
> -                 " -revoke %s/%s.crt",
> -                 PATH_OPENSSL, ca->batch, ca->sslcnf,
> -                 ca->sslpath, pass, ca->sslpath, ca->sslpath, keyname);
> -             system(cmd);
> -     }
> -
> -     snprintf(cmd, sizeof(cmd),
> -         "%s ca %s-config %s -keyfile %s/private/ca.key"
> -         " -key %s"
> -         " -gencrl"
> -         " -cert %s/ca.crt"
> -         " -crldays 365"
> -         " -out %s/ca.crl",
> -         PATH_OPENSSL, ca->batch, ca->sslcnf, ca->sslpath,
> -         pass, ca->sslpath, ca->sslpath);
> -     system(cmd);
> +             snprintf(path, sizeof(path), "%s/%s.crt", ca->sslpath, keyname);
> +             run(13, PATH_OPENSSL, "ca", ca->batch, "-config", ca->sslcnf,
> +                 "-keyfile", cakey, "-key", pass, "-cert", cacrt,
> +                 "-revoke", path);
> +     }
> +
> +     snprintf(path, sizeof(path), "%s/ca.crl", ca->sslpath);
> +     run(16, PATH_OPENSSL, "ca", ca->batch, "-config", ca->sslcnf,
> +         "-keyfile", cakey, "-key", pass, "-gencrl", "-cert", cacrt,
> +         "-crldays", "365", "-out", path);
>  
>       explicit_bzero(pass, len);
>       free(pass);
> @@ -996,7 +986,7 @@ ca_setup(char *caname, int create, int quiet, char *pass)
>       strlcat(ca->passfile, "/ikeca.passwd", sizeof(ca->passfile));
>  
>       if (quiet)
> -             strlcpy(ca->batch, "-batch ", sizeof(ca->batch));
> +             strlcpy(ca->batch, "-batch", sizeof(ca->batch));
>  
>       if (create == 0 && stat(ca->sslpath, &st) == -1) {
>               free(ca->caname);
> @@ -1016,3 +1006,37 @@ ca_setup(char *caname, int create, int quiet, char 
> *pass)
>  
>       return (ca);
>  }
> +
> +int static
> +run(int n, ...)
> +{
> +     pid_t pid, cpid;
> +     va_list ap;
> +     int i = 0, status;
> +     char **argv;
> +
> +     argv = reallocarray(NULL, n + 1, sizeof(char *));
> +
> +     va_start(ap, n);
> +     while (n--) {
> +             argv[i] = va_arg(ap, char *);
> +             // Ignore empty arguments for ca->batch
> +             if (argv[i][0] != '\0')
> +                     i++;
> +     }
> +     va_end(ap);
> +     argv[i] = NULL;
> +
> +     switch (cpid = fork()) {
> +     case -1:
> +             return -1;
> +     case 0:
> +             return execv(argv[0], argv);
> +     }
> +
> +     do {
> +             pid = waitpid(cpid, &status, 0);
> +     } while (pid == -1 && errno == EINTR);
> +
> +     return (pid == -1 ? -1 : WEXITSTATUS(status));
> +}
> 

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