apps/smime: Point out that the six operations are mutually exclusive and add check

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18917)

diff --git a/apps/smime.c b/apps/smime.c
index 4afef3d33396f58331cbcb0dc3f1d01d57993fae..59e96dcaec4b32ca20b3b8d7cf30c662d1ae1493 100644 (file)
--- a/apps/smime.c
+++ b/apps/smime.c
@@ -28,9 +28,9 @@ static int smime_cb(int ok, X509_STORE_CTX *ctx);
 #define SMIME_ENCRYPT   (1 | SMIME_OP)
 #define SMIME_DECRYPT   (2 | SMIME_IP)
 #define SMIME_SIGN      (3 | SMIME_OP | SMIME_SIGNERS)
+#define SMIME_RESIGN    (6 | SMIME_IP | SMIME_OP | SMIME_SIGNERS)
 #define SMIME_VERIFY    (4 | SMIME_IP)
 #define SMIME_PK7OUT    (5 | SMIME_IP | SMIME_OP)
-#define SMIME_RESIGN    (6 | SMIME_IP | SMIME_OP | SMIME_SIGNERS)
 
 typedef enum OPTION_choice {
     OPT_COMMON,
@@ -75,12 +75,12 @@ const OPTIONS smime_options[] = {
     {"sign", OPT_SIGN, '-', "Sign message"},
     {"resign", OPT_RESIGN, '-', "Resign a signed message"},
     {"verify", OPT_VERIFY, '-', "Verify signed message"},
+    {"pk7out", OPT_PK7OUT, '-', "Output PKCS#7 structure"},
 
     OPT_SECTION("Signing/Encryption"),
     {"passin", OPT_PASSIN, 's', "Input file pass phrase source"},
     {"md", OPT_MD, 's', "Digest algorithm to use when signing or resigning"},
     {"", OPT_CIPHER, '-', "Any supported cipher"},
-    {"pk7out", OPT_PK7OUT, '-', "Output PKCS#7 structure"},
     {"nointern", OPT_NOINTERN, '-',
      "Don't search certificates in message for signer"},
     {"nodetach", OPT_NODETACH, '-', "Use opaque signing"},
@@ -129,6 +129,32 @@ const OPTIONS smime_options[] = {
     {NULL}
 };
 
+static const char *operation_name(int operation)
+{
+    switch (operation) {
+    case SMIME_ENCRYPT:
+        return "encrypt";
+    case SMIME_DECRYPT:
+        return "decrypt";
+    case SMIME_SIGN:
+        return "sign";
+    case SMIME_RESIGN:
+        return "resign";
+    case SMIME_VERIFY:
+        return "verify";
+    case SMIME_PK7OUT:
+        return "pk7out";
+    default:
+        return "(invalid operation)";
+    }
+}
+
+#define SET_OPERATION(op) \
+    ((operation != 0 && (operation != (op))) \
+     ? 0 * BIO_printf(bio_err, "%s: Cannot use -%s together with -%s\n", \
+                      prog, operation_name(op), operation_name(operation)) \
+     : (operation = (op)))
+
 int smime_main(int argc, char **argv)
 {
     CONF *conf = NULL;
@@ -188,22 +214,28 @@ int smime_main(int argc, char **argv)
             outfile = opt_arg();
             break;
         case OPT_ENCRYPT:
-            operation = SMIME_ENCRYPT;
+            if (!SET_OPERATION(SMIME_ENCRYPT))
+                goto end;
             break;
         case OPT_DECRYPT:
-            operation = SMIME_DECRYPT;
+            if (!SET_OPERATION(SMIME_DECRYPT))
+                goto end;
             break;
         case OPT_SIGN:
-            operation = SMIME_SIGN;
+            if (!SET_OPERATION(SMIME_SIGN))
+                goto end;
             break;
         case OPT_RESIGN:
-            operation = SMIME_RESIGN;
+            if (!SET_OPERATION(SMIME_RESIGN))
+                goto end;
             break;
         case OPT_VERIFY:
-            operation = SMIME_VERIFY;
+            if (!SET_OPERATION(SMIME_VERIFY))
+                goto end;
             break;
         case OPT_PK7OUT:
-            operation = SMIME_PK7OUT;
+            if (!SET_OPERATION(SMIME_PK7OUT))
+                goto end;
             break;
         case OPT_TEXT:
             flags |= PKCS7_TEXT;

diff --git a/doc/man1/openssl-smime.pod.in b/doc/man1/openssl-smime.pod.in
index e438c866c38307cc8792562648390ebbdc740c26..1460221e13178004334828a20f430767f295349d 100644 (file)
--- a/doc/man1/openssl-smime.pod.in
+++ b/doc/man1/openssl-smime.pod.in
@@ -59,7 +59,9 @@ and verify S/MIME messages.
 
 =head1 OPTIONS
 
-There are six operation options that set the type of operation to be performed.
+There are six operation options that set the type of operation to be performed:
+B<-encrypt>, B<-decrypt>, B<-sign>, B<-resign>, B<-verify>, and B<-pk7out>.
+These are mutually exclusive.
 The meaning of the other options varies according to the operation type.
 
 =over 4
@@ -88,6 +90,10 @@ Sign mail using the supplied certificate and private key. Input file is
 the message to be signed. The signed message in MIME format is written
 to the output file.
 
+=item B<-resign>
+
+Resign a message: take an existing message and one or more new signers.
+
 =item B<-verify>
 
 Verify signed mail. Expects a signed mail message on input and outputs
@@ -97,10 +103,6 @@ the signed data. Both clear text and opaque signing is supported.
 
 Takes an input message and writes out a PEM encoded PKCS#7 structure.
 
-=item B<-resign>
-
-Resign a message: take an existing message and one or more new signers.
-
 =item B<-in> I<filename>
 
 The input message to be encrypted or signed or the MIME message to