allow to specify TLS ciphers and protocols in smtp(1)

improvements from jmc@ schwarze@ tb@

ok tb@

diff --git a/usr.sbin/smtpd/smtp.1 b/usr.sbin/smtpd/smtp.1
index 1074065..f020fe6 100644 (file)
--- a/usr.sbin/smtpd/smtp.1
+++ b/usr.sbin/smtpd/smtp.1
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: smtp.1,v 1.9 2021/02/13 08:07:48 jmc Exp $
+.\"    $OpenBSD: smtp.1,v 1.10 2021/05/22 09:09:07 eric Exp $
 .\"
 .\" Copyright (c) 2018, Eric Faurot <eric@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: February 13 2021 $
+.Dd $Mdocdate: May 22 2021 $
 .Dt SMTP 1
 .Os
 .Sh NAME
@@ -27,6 +27,7 @@
 .Op Fl F Ar from
 .Op Fl H Ar helo
 .Op Fl s Ar server
+.Op Fl T Ar params
 .Op Ar recipient ...
 .Sh DESCRIPTION
 The
@@ -91,6 +92,26 @@ SMTP session with forced TLS on connection.
 .Pp
 Defaults to
 .Dq smtp://localhost:25 .
+.It Fl T Ar params
+Set specific parameters for TLS sessions.
+The
+.Ar params
+string is a comma or space separated list of options.
+The available options are:
+.Bl -tag -width Ds
+.It protocols Ns = Ns Ar value
+Specify the protocols to use.
+Refer to
+.Xr tls_config_parse_protocols 3
+for
+.Ar value .
+.It ciphers Ns = Ns Ar value
+Specify the allowed ciphers.
+Refer to
+.Xr tls_config_set_ciphers 3
+for
+.Ar value .
+.El
 .It Fl v
 Be more verbose.
 This option can be specified multiple times.

diff --git a/usr.sbin/smtpd/smtpc.c b/usr.sbin/smtpd/smtpc.c
index ca48604..4bf64fc 100644 (file)
--- a/usr.sbin/smtpd/smtpc.c
+++ b/usr.sbin/smtpd/smtpc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: smtpc.c,v 1.15 2021/04/10 10:19:19 eric Exp $ */
+/*     $OpenBSD: smtpc.c,v 1.16 2021/05/22 09:09:07 eric Exp $ */
 
 /*
  * Copyright (c) 2018 Eric Faurot <eric@openbsd.org>
@@ -48,22 +48,57 @@ static struct smtp_mail mail;
 static const char *servname = NULL;
 static struct tls_config *tls_config;
 
+static const char *protocols = NULL;
+static const char *ciphers = NULL;
+
 static void
 usage(void)
 {
        extern char *__progname;
 
        fprintf(stderr, "usage: %s [-Chnv] [-a authfile] [-F from] [-H helo] "
-           "[-s server] [recipient ...]\n", __progname);
+           "[-s server] [-T params] [recipient ...]\n", __progname);
        exit(1);
 }
 
+static void
+parse_tls_options(char *opt)
+{
+       static char * const tokens[] = {
+#define CIPHERS 0
+               "ciphers",
+#define PROTOCOLS 1
+               "protocols",
+               NULL };
+       char *value;
+
+       while (*opt) {
+               switch (getsubopt(&opt, tokens, &value)) {
+               case CIPHERS:
+                       if (value == NULL)
+                               fatalx("missing value for ciphers");
+                       ciphers = value;
+                       break;
+               case PROTOCOLS:
+                       if (value == NULL)
+                               fatalx("missing value for protocols");
+                       protocols = value;
+                       break;
+               case -1:
+                       if (suboptarg)
+                               fatalx("invalid TLS option \"%s\"", suboptarg);
+                       fatalx("missing TLS option");
+               }
+       }
+}
+
 int
 main(int argc, char **argv)
 {
        char hostname[256];
        FILE *authfile;
        int ch, i;
+       uint32_t protos;
        char *server = "localhost";
        char *authstr = NULL;
        size_t alloc = 0;
@@ -91,7 +126,7 @@ main(int argc, char **argv)
        memset(&mail, 0, sizeof(mail));
        mail.from = pw->pw_name;
 
-       while ((ch = getopt(argc, argv, "CF:H:S:a:hns:v")) != -1) {
+       while ((ch = getopt(argc, argv, "CF:H:S:T:a:hns:v")) != -1) {
                switch (ch) {
                case 'C':
                        params.tls_verify = 0;
@@ -105,6 +140,9 @@ main(int argc, char **argv)
                case 'S':
                        servname = optarg;
                        break;
+               case 'T':
+                       parse_tls_options(optarg);
+                       break;
                case 'a':
                        if ((authfile = fopen(optarg, "r")) == NULL)
                                fatal("%s: open", optarg);
@@ -159,6 +197,17 @@ main(int argc, char **argv)
        tls_config = tls_config_new();
        if (tls_config == NULL)
                fatal("tls_config_new");
+
+       if (protocols) {
+               if (tls_config_parse_protocols(&protos, protocols) == -1)
+                       fatalx("failed to parse protocol '%s'", protocols);
+               if (tls_config_set_protocols(tls_config, protos) == -1)
+                       fatalx("tls_config_set_protocols: %s",
+                           tls_config_error(tls_config));
+       }
+       if (ciphers && tls_config_set_ciphers(tls_config, ciphers) == -1)
+               fatalx("tls_config_set_ciphers: %s",
+                   tls_config_error(tls_config));
        if (tls_config_set_ca_file(tls_config, tls_default_ca_cert_file()) == -1)
                fatal("tls_set_ca_file");
        if (!params.tls_verify) {