1 files changed, 109 insertions, 0 deletions
diff --git a/src/mongo/util/base64.cpp b/src/mongo/util/base64.cpp
new file mode 100644
index 00000000000..aff06e26126
--- /dev/null
+++ b/src/mongo/util/base64.cpp
@@ -0,0 +1,109 @@
+// util/base64.cpp
+
+
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#include "pch.h"
+#include "base64.h"
+
+namespace mongo {
+    namespace base64 {
+
+        Alphabet alphabet;
+
+        void encode( stringstream& ss , const char * data , int size ) {
+            for ( int i=0; i<size; i+=3 ) {
+                int left = size - i;
+                const unsigned char * start = (const unsigned char*)data + i;
+
+                // byte 0
+                ss << alphabet.e(start[0]>>2);
+
+                // byte 1
+                unsigned char temp = ( start[0] << 4 );
+                if ( left == 1 ) {
+                    ss << alphabet.e(temp);
+                    break;
+                }
+                temp |= ( ( start[1] >> 4 ) & 0xF );
+                ss << alphabet.e(temp);
+
+                // byte 2
+                temp = ( start[1] & 0xF ) << 2;
+                if ( left == 2 ) {
+                    ss << alphabet.e(temp);
+                    break;
+                }
+                temp |= ( ( start[2] >> 6 ) & 0x3 );
+                ss << alphabet.e(temp);
+
+                // byte 3
+                ss << alphabet.e(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();
+        }
+
+        string encode( const string& s ) {
+            return encode( s.c_str() , s.size() );
+        }
+
+
+        void decode( stringstream& ss , const string& s ) {
+            uassert( 10270 ,  "invalid base64" , s.size() % 4 == 0 );
+            const unsigned char * data = (const unsigned char*)s.c_str();
+            int size = s.size();
+
+            unsigned char buf[3];
+            for ( int i=0; i<size; i+=4) {
+                const unsigned char * start = data + i;
+                buf[0] = ( ( alphabet.decode[start[0]] << 2 ) & 0xFC ) | ( ( alphabet.decode[start[1]] >> 4 ) & 0x3 );
+                buf[1] = ( ( alphabet.decode[start[1]] << 4 ) & 0xF0 ) | ( ( alphabet.decode[start[2]] >> 2 ) & 0xF );
+                buf[2] = ( ( alphabet.decode[start[2]] << 6 ) & 0xC0 ) | ( ( alphabet.decode[start[3]] & 0x3F ) );
+
+                int len = 3;
+                if ( start[3] == '=' ) {
+                    len = 2;
+                    if ( start[2] == '=' ) {
+                        len = 1;
+                    }
+                }
+                ss.write( (const char*)buf , len );
+            }
+        }
+
+        string decode( const string& s ) {
+            stringstream ss;
+            decode( ss , s );
+            return ss.str();
+        }
+
+    }
+}
+