Needed by tests for empty-password cases.

commit 1e123231769fe640f446442cb210664d280ccbac

Author: Greg Hudson <ghudson@mit.edu>

Date:   Fri May 24 13:16:52 2013 -0400

    Fix rc4 string-to-key on unterminated inputs

    The internal UTF-8 to UCS-2 conversion functions did not properly

    respect their length arguments, instead assuming that the input string

    is terminated with a zero bytes.  As a result,

    krb5int_arcfour_string_to_key could fail on unterminated inputs.  Fix

    the underlying support functions to read their inputs only up to the

    specified length.

    ticket: 7643 (new)

diff --git a/src/util/support/utf8_conv.c b/src/util/support/utf8_conv.c

index d580bbc..b8bf989 100644

--- a/src/util/support/utf8_conv.c

+++ b/src/util/support/utf8_conv.c

@@ -78,7 +78,8 @@ k5_utf8s_to_ucs2s(krb5_ucs2 *ucs2str,

     /* If input ptr is NULL or empty... */

     if (utf8str == NULL || *utf8str == '\0') {

-        *ucs2str = 0;

+        if (ucs2str != NULL)

+            *ucs2str = 0;

         return 0;

     }

@@ -119,9 +120,7 @@ k5_utf8s_to_ucs2s(krb5_ucs2 *ucs2str,

         ucs2len++;              /* Count number of wide chars stored/required */

     }

-    assert(ucs2len < count);

-

-    if (ucs2str != NULL) {

+    if (ucs2str != NULL && ucs2len < count) {

         /* Add null terminator if there's room in the buffer. */

         ucs2str[ucs2len] = 0;

     }

@@ -172,12 +171,13 @@ krb5int_utf8cs_to_ucs2s(const char *utf8s,

         return ENOMEM;

     }

-    len = k5_utf8s_to_ucs2s(*ucs2s, utf8s, chars + 1, 0);

+    len = k5_utf8s_to_ucs2s(*ucs2s, utf8s, chars, 0);

     if (len < 0) {

         free(*ucs2s);

         *ucs2s = NULL;

         return EINVAL;

     }

+    (*ucs2s)[chars] = 0;

     if (ucs2chars != NULL) {

         *ucs2chars = chars;

@@ -223,21 +223,23 @@ krb5int_utf8cs_to_ucs2les(const char *utf8s,

 {

     ssize_t len;

     size_t chars;

+    krb5_ucs2 *ucs2s;

-    chars = krb5int_utf8c_chars(utf8s, utf8slen);

+    *ucs2les = NULL;

-    *ucs2les = (unsigned char *)malloc((chars + 1) * sizeof(krb5_ucs2));

-    if (*ucs2les == NULL) {

+    chars = krb5int_utf8c_chars(utf8s, utf8slen);

+    ucs2s = malloc((chars + 1) * sizeof(krb5_ucs2));

+    if (ucs2s == NULL)

         return ENOMEM;

-    }

-    len = k5_utf8s_to_ucs2s((krb5_ucs2 *)*ucs2les, utf8s, chars + 1, 1);

+    len = k5_utf8s_to_ucs2s(ucs2s, utf8s, chars, 1);

     if (len < 0) {

-        free(*ucs2les);

-        *ucs2les = NULL;

+        free(ucs2s);

         return EINVAL;

     }

+    ucs2s[chars] = 0;

+    *ucs2les = (unsigned char *)ucs2s;

     if (ucs2leslen != NULL) {

         *ucs2leslen = chars * sizeof(krb5_ucs2);

     }

@@ -402,13 +404,14 @@ krb5int_ucs2cs_to_utf8s(const krb5_ucs2 *ucs2s,

         return ENOMEM;

     }

-    len = k5_ucs2s_to_utf8s(*utf8s, (krb5_ucs2 *)ucs2s,

-                            (size_t)len + 1, (ssize_t)ucs2slen, 0);

+    len = k5_ucs2s_to_utf8s(*utf8s, (krb5_ucs2 *)ucs2s, (size_t)len,

+                            (ssize_t)ucs2slen, 0);

     if (len < 0) {

         free(*utf8s);

         *utf8s = NULL;

         return EINVAL;

     }

+    (*utf8s)[len] = '\0';

     if (utf8slen != NULL) {

         *utf8slen = len;

@@ -438,13 +441,14 @@ krb5int_ucs2lecs_to_utf8s(const unsigned char *ucs2les,

         return ENOMEM;

     }

-    len = k5_ucs2s_to_utf8s(*utf8s, (krb5_ucs2 *)ucs2les,

-                            (size_t)len + 1, (ssize_t)ucs2leslen, 1);

+    len = k5_ucs2s_to_utf8s(*utf8s, (krb5_ucs2 *)ucs2les, (size_t)len,

+                            (ssize_t)ucs2leslen, 1);

     if (len < 0) {

         free(*utf8s);

         *utf8s = NULL;

         return EINVAL;

     }

+    (*utf8s)[len] = '\0';

     if (utf8slen != NULL) {

         *utf8slen = len;