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 , 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);
 }