Fix old bug in contrib/sslinfo: X509_NAME_to_text freed the BIO_s_mem buffer

it was using too soon.  In a situation where pg_do_encoding_conversion is
a no-op, this led to garbage data returned.

In HEAD, also modify the code that's ensuring null termination to make it
a tad more obvious what's happening.

diff --git a/contrib/sslinfo/sslinfo.c b/contrib/sslinfo/sslinfo.c
index a215abb8b6e76a801248117e245372b7c1728b8f..a8145653c0c55dee362b1b3b033a5be4ef6e9892 100644 (file)
--- a/contrib/sslinfo/sslinfo.c
+++ b/contrib/sslinfo/sslinfo.c
@@ -4,7 +4,7 @@
  * Written by Victor B. Wagner <vitus@cryptocom.ru>, Cryptocom LTD
  * This file is distributed under BSD-style license.
  *
- * $PostgreSQL: pgsql/contrib/sslinfo/sslinfo.c,v 1.7 2008/03/25 22:42:42 tgl Exp $
+ * $PostgreSQL: pgsql/contrib/sslinfo/sslinfo.c,v 1.8 2008/11/10 14:57:38 tgl Exp $
  */
 
 #include "postgres.h"
@@ -113,9 +113,9 @@ ssl_client_serial(PG_FUNCTION_ARGS)
 Datum
 ASN1_STRING_to_text(ASN1_STRING *str)
 {
-       BIO                *membuf = NULL;
-       size_t          size,
-                               outlen;
+       BIO                *membuf;
+       size_t          size;
+       char            nullterm;
        char       *sp;
        char       *dp;
        text       *result;
@@ -125,16 +125,15 @@ ASN1_STRING_to_text(ASN1_STRING *str)
        ASN1_STRING_print_ex(membuf, str,
                                                 ((ASN1_STRFLGS_RFC2253 & ~ASN1_STRFLGS_ESC_MSB)
                                                  | ASN1_STRFLGS_UTF8_CONVERT));
-
-       outlen = 0;
-       BIO_write(membuf, &outlen, 1);
+       /* ensure null termination of the BIO's content */
+       nullterm = '\0';
+       BIO_write(membuf, &nullterm, 1);
        size = BIO_get_mem_data(membuf, &sp);
        dp = (char *) pg_do_encoding_conversion((unsigned char *) sp,
                                                                                        size - 1,
                                                                                        PG_UTF8,
                                                                                        GetDatabaseEncoding());
        result = cstring_to_text(dp);
-
        if (dp != sp)
                pfree(dp);
        BIO_free(membuf);
@@ -271,6 +270,7 @@ X509_NAME_to_text(X509_NAME *name)
        ASN1_STRING *v;
        const char *field_name;
        size_t          size;
+       char            nullterm;
        char       *sp;
        char       *dp;
        text       *result;
@@ -290,24 +290,18 @@ X509_NAME_to_text(X509_NAME *name)
                                                          | ASN1_STRFLGS_UTF8_CONVERT));
        }
 
-       i = 0;
-       BIO_write(membuf, &i, 1);
+       /* ensure null termination of the BIO's content */
+       nullterm = '\0';
+       BIO_write(membuf, &nullterm, 1);
        size = BIO_get_mem_data(membuf, &sp);
-
        dp = (char *) pg_do_encoding_conversion((unsigned char *) sp,
                                                                                        size - 1,
                                                                                        PG_UTF8,
                                                                                        GetDatabaseEncoding());
-       BIO_free(membuf);
-
        result = cstring_to_text(dp);
-
-       /*
-        * pg_do_encoding_conversion has annoying habit of returning source
-        * pointer
-        */
        if (dp != sp)
                pfree(dp);
+       BIO_free(membuf);
 
        PG_RETURN_TEXT_P(result);
 }