Juan Lang : rsaenh: Explicitly clear unused memory when exporting a private key.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 49c11910d8e0856715d14567c48a2489ff92d80a
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=49c11910d8e0856715d14567c48a2489ff92d80a

Author: Juan Lang <juan.lang at gmail.com>
Date:   Thu Nov  5 09:49:00 2009 -0800

rsaenh: Explicitly clear unused memory when exporting a private key.

---

 dlls/rsaenh/implglue.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/dlls/rsaenh/implglue.c b/dlls/rsaenh/implglue.c
index 68a9380..3477210 100644
--- a/dlls/rsaenh/implglue.c
+++ b/dlls/rsaenh/implglue.c
@@ -397,24 +397,45 @@ BOOL export_private_key_impl(BYTE *pbDest, const KEY_CONTEXT *pKeyContext, DWORD
 {
     mp_to_unsigned_bin(&pKeyContext->rsa.N, pbDest);
     reverse_bytes(pbDest, dwKeyLen);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.N) < dwKeyLen)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.N), 0,
+               dwKeyLen - mp_unsigned_bin_size(&pKeyContext->rsa.N));
     pbDest += dwKeyLen;
     mp_to_unsigned_bin(&pKeyContext->rsa.p, pbDest);
     reverse_bytes(pbDest, (dwKeyLen+1)>>1);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.p) < (dwKeyLen+1)>>1)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.p), 0,
+               ((dwKeyLen+1)>>1) - mp_unsigned_bin_size(&pKeyContext->rsa.p));
     pbDest += (dwKeyLen+1)>>1;
     mp_to_unsigned_bin(&pKeyContext->rsa.q, pbDest);
     reverse_bytes(pbDest, (dwKeyLen+1)>>1);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.q) < (dwKeyLen+1)>>1)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.q), 0,
+               ((dwKeyLen+1)>>1) - mp_unsigned_bin_size(&pKeyContext->rsa.q));
     pbDest += (dwKeyLen+1)>>1;
     mp_to_unsigned_bin(&pKeyContext->rsa.dP, pbDest);
     reverse_bytes(pbDest, (dwKeyLen+1)>>1);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.dP) < (dwKeyLen+1)>>1)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.dP), 0,
+               ((dwKeyLen+1)>>1) - mp_unsigned_bin_size(&pKeyContext->rsa.dP));
     pbDest += (dwKeyLen+1)>>1;
     mp_to_unsigned_bin(&pKeyContext->rsa.dQ, pbDest);
     reverse_bytes(pbDest, (dwKeyLen+1)>>1);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.dQ) < (dwKeyLen+1)>>1)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.dQ), 0,
+               ((dwKeyLen+1)>>1) - mp_unsigned_bin_size(&pKeyContext->rsa.dQ));
     pbDest += (dwKeyLen+1)>>1;
     mp_to_unsigned_bin(&pKeyContext->rsa.qP, pbDest);
     reverse_bytes(pbDest, (dwKeyLen+1)>>1);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.qP) < (dwKeyLen+1)>>1)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.qP), 0,
+               ((dwKeyLen+1)>>1) - mp_unsigned_bin_size(&pKeyContext->rsa.qP));
     pbDest += (dwKeyLen+1)>>1;
     mp_to_unsigned_bin(&pKeyContext->rsa.d, pbDest);
     reverse_bytes(pbDest, dwKeyLen);
+    if (mp_unsigned_bin_size(&pKeyContext->rsa.d) < dwKeyLen)
+        memset(pbDest + mp_unsigned_bin_size(&pKeyContext->rsa.d), 0,
+               dwKeyLen - mp_unsigned_bin_size(&pKeyContext->rsa.d));
     *pdwPubExp = (DWORD)mp_get_int(&pKeyContext->rsa.e);
 
     return TRUE;