fix base64 issue

3 files changed, 55 insertions, 16 deletions

diff --git a/dbtests/basictests.cpp b/dbtests/basictests.cpp
index 5bf22b83f0b..2a9ecfbf9e0 100644
--- a/dbtests/basictests.cpp
+++ b/dbtests/basictests.cpp
@@ -55,6 +55,29 @@ namespace BasicTests {
             ASSERT_EQUALS( s , base64::decode( base64::encode( s ) ) );
         }
         
+        void roundTrip( const char * data , int len ){
+            string s = base64::encode( data , len );
+            string out = base64::decode( s );
+            ASSERT_EQUALS( out.size() , len );
+            bool broke = false;
+            for ( int i=0; i<len; i++ ){
+                if ( data[i] != out[i] )
+                    broke = true;
+            }
+            if ( ! broke )
+                return;
+
+            cout << s << endl;
+            for ( int i=0; i<len; i++ )
+                cout << hex << ( data[i] & 0xFF ) << dec << " ";
+            cout << endl;
+            for ( int i=0; i<len; i++ )
+                cout << hex << ( out[i] & 0xFF ) << dec << " ";
+            cout << endl;
+            
+            ASSERT(0);
+        }
+        
         void run(){
 
             ASSERT_EQUALS( "ZWxp" , base64::encode( "eli" , 3 ) );
@@ -71,6 +94,19 @@ namespace BasicTests {
             roundTrip( "eliot" );
             roundTrip( "eliots" );
             roundTrip( "eliotsz" );
+            
+            char z[] = { 0x1 , 0x2 , 0x3 , 0x4 };
+            roundTrip( z , 4 );
+            
+            char y[] = {
+                0x01, 0x10, 0x83, 0x10, 0x51, 0x87, 0x20, 0x92, 0x8B, 0x30,
+                0xD3, 0x8F, 0x41, 0x14, 0x93, 0x51, 0x55, 0x97, 0x61, 0x96,
+                0x9B, 0x71, 0xD7, 0x9F, 0x82, 0x18, 0xA3, 0x92, 0x59, 0xA7,
+                0xA2, 0x9A, 0xAB, 0xB2, 0xDB, 0xAF, 0xC3, 0x1C, 0xB3, 0xD3,
+                0x5D, 0xB7, 0xE3, 0x9E, 0xBB, 0xF3, 0xDF, 0xBF
+            };
+            roundTrip( y , 4 );
+            roundTrip( y , 40 );
         }
     };
     
diff --git a/util/base64.cpp b/util/base64.cpp
index 15b9cbbc3d3..ab2594888a8 100644
--- a/util/base64.cpp
+++ b/util/base64.cpp
@@ -49,8 +49,13 @@ namespace mongo {
                     assert( encode[i] == toupper( encode[i+26] ) );
             }
 
-
+            char e( int x ){
+                return encode[x&0x3f];
+            }
+            
+        private:
             const char * encode;
+        public:
             char * decode;
         } alphabet;
         
@@ -61,28 +66,28 @@ namespace mongo {
                 const char * start = data + i;
                 
                 // byte 0
-                ss << alphabet.encode[start[0]>>2];
+                ss << alphabet.e(start[0]>>2);
                 
                 // byte 1
-                char temp = ( start[0] & 0x3 ) << 4;
+                char temp = ( start[0] << 4 );
                 if ( left == 1 ){
-                    ss << alphabet.encode[temp];
+                    ss << alphabet.e(temp);
                     break;
                 }
-                temp |= start[1] >> 4;
-                ss << alphabet.encode[temp];
+                temp |= ( ( start[1] >> 4 ) & 0xF );
+                ss << alphabet.e(temp);
 
                 // byte 2
                 temp = ( start[1] & 0xF ) << 2;
                 if ( left == 2 ){
-                    ss << alphabet.encode[temp];
+                    ss << alphabet.e(temp);
                     break;
                 }
-                temp |= start[2] >> 6;
-                ss << alphabet.encode[temp];
+                temp |= ( ( start[2] >> 6 ) & 0x3 );
+                ss << alphabet.e(temp);
 
                 // byte 3
-                ss << alphabet.encode[start[2] & 0x3f];
+                ss << alphabet.e(start[2] & 0x3f);
             }
 
             int mod = size % 3;
@@ -114,12 +119,10 @@ namespace mongo {
             char buf[4];
             buf[3] = 0;
             for ( int i=0; i<size; i+=4){
-                memset( buf , 0 , 4 );
                 const char * start = data + i;
-                buf[0] = ( alphabet.decode[start[0]] << 2 ) | ( alphabet.decode[start[1]] >> 4 );
-                buf[1] = ( alphabet.decode[start[1]] << 4 ) | ( alphabet.decode[start[2]] >> 2 );
-                buf[2] = ( alphabet.decode[start[2]] << 6 ) | ( alphabet.decode[start[3]]  );
-
+                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 ) );
                 ss << buf;
             }
         }
diff --git a/util/base64.h b/util/base64.h
index 305e45af1c8..c9dde9c23dc 100644
--- a/util/base64.h
+++ b/util/base64.h
@@ -21,7 +21,7 @@
 namespace mongo {
     namespace base64 {
 
-        void encode( stringstream& ss , void * data , int size );
+        void encode( stringstream& ss , const char * data , int size );
         string encode( const char * data , int size );
         string encode( const string& s );