From bb62f3be6d7a1ee1fb323aefd2402b0d0075e74a Mon Sep 17 00:00:00 2001
From: w00t
Date: Sun, 6 Jan 2008 18:40:36 +0000
Subject: Backport r8651: SHA256 consistancy fix.

git-svn-id: http://svn.inspircd.org/repository/branches/1_1_stable@8652 e03df62e-2008-0410-955e-edbf42e46eb7
---
 src/modules/m_sha256.cpp | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

(limited to 'src/modules/m_sha256.cpp')

diff --git a/src/modules/m_sha256.cpp b/src/modules/m_sha256.cpp
index 547e7655c..c15799ea1 100644
--- a/src/modules/m_sha256.cpp
+++ b/src/modules/m_sha256.cpp
@@ -189,7 +189,25 @@ class ModuleSHA256 : public Module
 	
 	void SHA256Update(SHA256Context *ctx, unsigned char *message, unsigned int len)
 	{
-		unsigned int rem_len = SHA256_BLOCK_SIZE - ctx->len;
+		/*
+		 * XXX here be dragons!
+		 * After many hours of pouring over this, I think I've found the problem.
+		 * When Special created our module from the reference one, he used:
+		 *
+		 * unsigned int rem_len = SHA256_BLOCK_SIZE - ctx->len;
+		 *
+		 * instead of the reference's version of:
+		 *
+		 * unsigned int tmp_len = SHA256_BLOCK_SIZE - ctx->len;
+		 * unsigned int rem_len = len < tmp_len ? len : tmp_len;
+		 *
+		 * I've changed back to the reference version of this code, and it seems to work with no errors.
+		 * So I'm inclined to believe this was the problem..
+		 * -- w00t (January 06, 2008)
+		 */
+		unsigned int tmp_len = SHA256_BLOCK_SIZE - ctx->len;
+		unsigned int rem_len = len < tmp_len ? len : tmp_len;
+
 		memcpy(&ctx->block[ctx->len], message, rem_len);
 		if (ctx->len + len < SHA256_BLOCK_SIZE)
 		{
-- 
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