simple base64::encode

2 files changed, 113 insertions, 0 deletions

diff --git a/util/base64.cpp b/util/base64.cpp
new file mode 100644
index 00000000000..3a44745111f
--- /dev/null
+++ b/util/base64.cpp
@@ -0,0 +1,86 @@
+// util/base64.cpp
+
+
+/**
+*    Copyright (C) 2008 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "stdafx.h"
+
+namespace mongo {
+    namespace base64 {
+
+        const char * alphabet = 
+            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+            "abcdefghijklmnopqrstuvwxyz"
+            "0123456789"
+            "+/";
+
+        void testAlphabet(){
+            assert( strlen( alphabet ) == 64 );
+            for ( int i=0; i<26; i++ )
+                assert( alphabet[i] == toupper( alphabet[i+26] ) );
+        }
+        
+        
+        void encode( stringstream& ss , const char * data , int size ){
+            for ( int i=0; i<size; i+=3 ){
+                int left = size - i;
+                const char * start = data + i;
+                
+                // byte 0
+                ss << alphabet[start[0]>>2];
+                
+                // byte 1
+                char temp = ( start[0] & 0x3 ) << 4;
+                if ( left == 1 ){
+                    ss << alphabet[temp];
+                    break;
+                }
+                temp |= start[1] >> 4;
+                ss << alphabet[temp];
+
+                // byte 2
+                temp = ( start[1] & 0xF ) << 2;
+                if ( left == 2 ){
+                    ss << alphabet[temp];
+                    break;
+                }
+                temp |= start[2] >> 6;
+                ss << alphabet[temp];
+
+                // byte 3
+                ss << alphabet[start[2] & 0x3f];
+            }
+
+            int mod = size % 3;
+            if ( mod == 1 ){
+                ss << "==";
+            }
+            else if ( mod == 2 ){
+                ss << "=";
+            }
+        }
+
+
+        string encode( const char * data , int size ){
+            stringstream ss;
+            encode( ss , data ,size );
+            return ss.str();
+        }
+
+    }
+}
+
diff --git a/util/base64.h b/util/base64.h
new file mode 100644
index 00000000000..416b2ce9502
--- /dev/null
+++ b/util/base64.h
@@ -0,0 +1,27 @@
+// util/base64.h
+
+/**
+*    Copyright (C) 2008 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "stdafx.h"
+
+namespace mongo {
+    namespace base64 {
+        void encode( stringstream& ss , void * data , int size );
+        string encode( const char * data , int size );
+        void testAlphabet();
+    }
+}