From 1739aea5358f2a9689b4d38b19d3f07ababd4b4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mois=C3=A9s=20Guimar=C3=A3es?= <moisesguimaraesm@gmail.com>
Date: Fri, 4 Jul 2014 10:15:39 -0300
Subject: [PATCH] asn: refactoring SignCert to reduce stack usage: 512 bytes -
 pointers size moved to the heap. --- variable sig moved to the heap (1152
 bytes saved)

---
 ctaocrypt/src/asn.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/ctaocrypt/src/asn.c b/ctaocrypt/src/asn.c
index 7ecab8b11..0031d3661 100644
--- a/ctaocrypt/src/asn.c
+++ b/ctaocrypt/src/asn.c
@@ -5851,21 +5851,28 @@ int MakeCertReq(Cert* cert, byte* derBuffer, word32 derSz,
 int SignCert(int requestSz, int sType, byte* buffer, word32 buffSz,
              RsaKey* rsaKey, ecc_key* eccKey, RNG* rng)
 {
-    byte    sig[MAX_ENCODED_SIG_SZ];
-    int     sigSz;
+    int sigSz;
+    DECLARE_ARRAY(byte, sig, MAX_ENCODED_SIG_SZ);
 
     if (requestSz < 0)
         return requestSz;
 
-    sigSz = MakeSignature(buffer, requestSz, sig, sizeof(sig), rsaKey, eccKey,
-                          rng, sType);
-    if (sigSz < 0)
-        return sigSz; 
+    if (!CREATE_ARRAY(byte, sig, MAX_ENCODED_SIG_SZ))
+        return MEMORY_E;
 
-    if (requestSz + MAX_SEQ_SZ * 2 + sigSz > (int)buffSz)
-        return BUFFER_E; 
+    sigSz = MakeSignature(buffer, requestSz, sig, MAX_ENCODED_SIG_SZ, rsaKey,
+                          eccKey, rng, sType);
 
-    return AddSignature(buffer, requestSz, sig, sigSz, sType);
+    if (sigSz >= 0) {
+        if (requestSz + MAX_SEQ_SZ * 2 + sigSz > (int)buffSz)
+            sigSz = BUFFER_E;
+        else
+            sigSz = AddSignature(buffer, requestSz, sig, sigSz, sType);
+    }
+    
+    DESTROY_ARRAY(sig);
+
+    return sigSz;
 }