RT2547: Tighten perms on generated privkey files

When generating a private key, try to make the output file be readable
only by the owner.  Put it in CHANGES file since it might be noticeable.

Add "int private" flag to apps that write private keys, and check that it's
set whenever we do write a private key.  Checked via assert so that this
bug (security-related) gets fixed.  Thanks to Viktor for help in tracing
the code-paths where private keys are written.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/apps/ecparam.c b/apps/ecparam.c
index ae755735b7..a0781c525b 100644
--- a/apps/ecparam.c
+++ b/apps/ecparam.c
@@ -70,7 +70,6 @@
 
 #include <openssl/opensslconf.h>
 #ifndef OPENSSL_NO_EC
-# include <assert.h>
 # include <stdio.h>
 # include <stdlib.h>
 # include <time.h>
@@ -142,8 +141,8 @@ int ecparam_main(int argc, char **argv)
     unsigned char *buffer = NULL;
     OPTION_CHOICE o;
     int asn1_flag = OPENSSL_EC_NAMED_CURVE, new_asn1_flag = 0;
-    int informat = FORMAT_PEM, outformat = FORMAT_PEM, noout = 0, C = 0, ret =
-        1;
+    int informat = FORMAT_PEM, outformat = FORMAT_PEM, noout = 0, C = 0;
+    int ret = 1, private = 0;
     int list_curves = 0, no_seed = 0, check = 0, new_form = 0;
     int text = 0, i, need_rand = 0, genkey = 0;
 
@@ -219,6 +218,7 @@ int ecparam_main(int argc, char **argv)
     }
     argc = opt_num_rest();
     argv = opt_rest();
+    private = genkey ? 1 : 0;
 
     if (!app_load_modules(NULL))
         goto end;
@@ -226,7 +226,7 @@ int ecparam_main(int argc, char **argv)
     in = bio_open_default(infile, RB(informat));
     if (in == NULL)
         goto end;
-    out = bio_open_default(outfile, WB(outformat));
+    out = bio_open_owner(outfile, WB(outformat), private);
     if (out == NULL)
         goto end;
 
@@ -473,6 +473,7 @@ int ecparam_main(int argc, char **argv)
             EC_KEY_free(eckey);
             goto end;
         }
+        assert(private);
         if (outformat == FORMAT_ASN1)
             i = i2d_ECPrivateKey_bio(out, eckey);
         else