From 379110a8a27316dcf4479895582018be675be573 Mon Sep 17 00:00:00 2001
From: seelabs <scott.determan@yahoo.com>
Date: Sat, 26 Sep 2015 20:15:20 -0400
Subject: [PATCH] Improve treatment of signature components

---
 src/ripple/crypto/impl/ECDSACanonical.cpp | 2 +-
 src/ripple/crypto/impl/RFC1751.cpp        | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/ripple/crypto/impl/ECDSACanonical.cpp b/src/ripple/crypto/impl/ECDSACanonical.cpp
index 66ad596ab..6cdd0e2d7 100644
--- a/src/ripple/crypto/impl/ECDSACanonical.cpp
+++ b/src/ripple/crypto/impl/ECDSACanonical.cpp
@@ -98,7 +98,7 @@ public:
         : m_skip (0)
     {
         // The format is: <02> <length of signature> <signature>
-        if ((sig[0] != 0x02) || (size < 3))
+        if ((size < 3) || (sig[0] != 0x02))
             return;
 
         std::size_t const len (sig[1]);
diff --git a/src/ripple/crypto/impl/RFC1751.cpp b/src/ripple/crypto/impl/RFC1751.cpp
index 9f9a8720a..009083c0c 100644
--- a/src/ripple/crypto/impl/RFC1751.cpp
+++ b/src/ripple/crypto/impl/RFC1751.cpp
@@ -271,12 +271,13 @@ unsigned long RFC1751::extract (char const* s, int start, int length)
     assert (length >= 0);
     assert (start + length <= 66);
 
+    int const shiftR = 24 - (length + (start % 8));
     cl = s[start / 8];                      // get components
-    cc = s[start / 8 + 1];
-    cr = s[start / 8 + 2];
+    cc = (shiftR < 16) ? s[start / 8 + 1] : 0;
+    cr = (shiftR < 8) ? s[start / 8 + 2] : 0;
 
     x = ((long) (cl << 8 | cc) << 8 | cr) ; // Put bits together
-    x = x >> (24 - (length + (start % 8))); // Right justify number
+    x = x >> shiftR; // Right justify number
     x = ( x & (0xffff >> (16 - length) ) ); // Trim extra bits.
 
     return x;