Clean up challenge generation to not include character 0x7F, and fix some other thing...

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@11591 e03df62e-2008-0410-955e-edbf42e46eb7

diff --git a/src/modules/m_spanningtree/hmac.cpp b/src/modules/m_spanningtree/hmac.cpp
index 62cf5c114177445f05ad9e94d71939c224aaf446..e1d46d0d974da1ce9d33f6d5999f98d88b1fc219 100644 (file)
--- a/src/modules/m_spanningtree/hmac.cpp
+++ b/src/modules/m_spanningtree/hmac.cpp
@@ -68,7 +68,8 @@ std::string TreeSocket::MakePass(const std::string &password, const std::string
                 * Note that we are encoding the hex hash, not the binary
                 * output of the hash which is slightly different to standard.
                 *
-                * Don't ask me why its always 0x5c and 0x36... it just is.
+                * 5c and 36 were chosen as part of the HMAC standard, because they
+                * flip the bits in a way likely to strengthen the function.
                 */
                std::string hmac1, hmac2;
 
@@ -98,21 +99,17 @@ std::string TreeSocket::RandString(unsigned int ilength)
 {
        char* randombuf = new char[ilength+1];
        std::string out;
-#ifdef WINDOWS
-       int f = -1;
-#else
+#ifndef WINDOWS
        int f = open("/dev/urandom", O_RDONLY, 0);
-#endif
 
        if (f >= 0)
        {
-#ifndef WINDOWS
-               if (read(f, randombuf, ilength) < 1)
-                       ServerInstance->Logs->Log("m_spanningtree", DEFAULT, "There are crack smoking monkeys in your kernel (in other words, nonblocking /dev/urandom blocked.)");
+               if (read(f, randombuf, ilength) < ilength)
+                       ServerInstance->Logs->Log("m_spanningtree", DEFAULT, "Entropy source has gone predictable (did not return enough data)");
                close(f);
-#endif
        }
        else
+#endif
        {
                for (unsigned int i = 0; i < ilength; i++)
                        randombuf[i] = rand();
@@ -120,8 +117,8 @@ std::string TreeSocket::RandString(unsigned int ilength)
 
        for (unsigned int i = 0; i < ilength; i++)
        {
-               char randchar = static_cast<char>((randombuf[i] & 0x7F) | 0x21);
-               out += (randchar == '=' ? '_' : randchar);
+               char randchar = static_cast<char>(0x3F + (randombuf[i] & 0x3F));
+               out += randchar;
        }
 
        delete[] randombuf;