DKIM: fix buffer overflow in verify

[exim.git] / src / src / pdkim / pdkim.c

diff --git a/src/src/pdkim/pdkim.c b/src/src/pdkim/pdkim.c
index eec1a9c1621268d94fbac86295b9547c3bea99d2..df507381f7ad8e9e265a4059039739736d328967 100644 (file)
--- a/src/src/pdkim/pdkim.c
+++ b/src/src/pdkim/pdkim.c
@@ -710,7 +710,7 @@ if (b->canon_method == PDKIM_CANON_RELAXED)
   if (!relaxed_data)
     {
     BOOL seen_wsp = FALSE;
-    const uschar * p;
+    const uschar * p, * r;
     int q = 0;
 
     /* We want to be able to free this else we allocate
@@ -721,7 +721,7 @@ if (b->canon_method == PDKIM_CANON_RELAXED)
     relaxed_data = store_malloc(sizeof(blob) + orig_data->len+1);
     relaxed_data->data = US (relaxed_data+1);
 
-    for (p = orig_data->data; *p; p++)
+    for (p = orig_data->data, r = p + orig_data->len; p < r; p++)
       {
       char c = *p;
       if (c == '\r')
@@ -848,6 +848,7 @@ ctx->linebuf_offset = 0;
 
 /* -------------------------------------------------------------------------- */
 /* Call from pdkim_feed below for processing complete body lines */
+/* NOTE: the line is not NUL-terminated; but we have a count */
 
 static void
 pdkim_bodyline_complete(pdkim_ctx * ctx)