PL/SQL BASE64 Encode/Decode

SELECT UTL_RAW.CAST_TO_VARCHAR2(UTL_ENCODE.BASE64_ENCODE(UTL_RAW.CAST_TO_RAW('1234nextguide'))) FROM dual;
SELECT UTL_RAW.CAST_TO_VARCHAR2(UTL_ENCODE.BASE64_DECODE(UTL_RAW.CAST_TO_RAW('MTIzNG5leHRndWlkZQ=='))) FROM dual;

SELECT UTL_ENCODE.TEXT_ENCODE('1234nextguide', 'WE8ISO8859P1', 1) FROM dual;
SELECT UTL_ENCODE.TEXT_DECODE('MTIzNG5leHRndWlkZQ==', 'WE8ISO8859P1', 1) FROM dual;

/*------------------------------------------------------------------------------
-- 개체명 : B2C
-- 생성일 : 2010-03-22 오후 3:03:32
-- 최종수정일 : 2010-03-22 오후 3:03:39
-- 상태 : VALID
------------------------------------------------------------------------------*/
CREATE OR REPLACE FUNCTION B2C(B IN BLOB) RETURN CLOB -- TYPECASTS BLOB TO CLOB (BINARY CONVERSION)
IS
    pos       PLS_INTEGER  := 1;
    buffer    VARCHAR2( 32767 );
    res       CLOB;
    lob_len   PLS_INTEGER  := DBMS_LOB.getLength(b);
BEGIN
    DBMS_LOB.createTemporary(res, TRUE);
    DBMS_LOB.OPEN(res, DBMS_LOB.LOB_ReadWrite);

    LOOP
        buffer := UTL_RAW.CAST_TO_VARCHAR2(DBMS_LOB.SUBSTR(b, 16000, pos));

        IF LENGTH( buffer ) > 0
        THEN
            DBMS_LOB.writeAppend( res, LENGTH( buffer ), buffer );
        END IF;

        pos := pos + 16000;
        EXIT WHEN pos > lob_len;
    END LOOP;

    RETURN res; -- res is OPEN here
END b2c;

/*------------------------------------------------------------------------------
-- 개체명 : C2B
-- 생성일 : 2010-03-22 오후 3:03:32
-- 최종수정일 : 2010-03-22 오후 3:03:39
-- 상태 : VALID
------------------------------------------------------------------------------*/
CREATE OR REPLACE FUNCTION C2B(C IN CLOB) RETURN BLOB -- TYPECASTS CLOB TO BLOB (BINARY CONVERSION)
IS
	pos       PLS_INTEGER  := 1;
    buffer    RAW( 32767 );
    res       BLOB;
    lob_len   PLS_INTEGER  := DBMS_LOB.getLength(c);
BEGIN
    DBMS_LOB.createTemporary(res, TRUE);
    DBMS_LOB.OPEN(res, DBMS_LOB.LOB_ReadWrite);

    LOOP
        buffer := UTL_RAW.CAST_TO_RAW(DBMS_LOB.SUBSTR(c, 16000, pos));

        IF UTL_RAW.LENGTH(buffer) > 0
        THEN
            DBMS_LOB.writeAppend(res, UTL_RAW.LENGTH(buffer), buffer);
        END IF;

        pos := pos + 16000;

        EXIT WHEN pos > lob_len;
    END LOOP;

    RETURN res; -- res is OPEN here
END c2b;

/*------------------------------------------------------------------------------
-- 개체명 : BASE64_B2C
-- 생성일 : 2010-03-22 오후 3:03:32
-- 최종수정일 : 2010-03-22 오후 3:03:39
-- 상태 : VALID
------------------------------------------------------------------------------*/
CREATE OR REPLACE FUNCTION BASE64_B2C(B IN BLOB) RETURN CLOB
IS
	v_buffer_size	INTEGER  := 4096;
	v_buffer_raw	RAW(4096);
	v_offset		INTEGER DEFAULT 1;
	v_clob			CLOB;
BEGIN
	DBMS_LOB.createTemporary(v_clob, FALSE, DBMS_LOB.CALL);

	LOOP
		BEGIN
			DBMS_LOB.READ(b, v_buffer_size, v_offset, v_buffer_raw);
			EXCEPTION
				WHEN NO_DATA_FOUND THEN
            EXIT;
        END;

        v_offset := v_offset + v_buffer_size;
        DBMS_LOB.APPEND(v_clob, to_clob(utl_raw.cast_to_varchar2(utl_encode.base64_encode(v_buffer_raw))));
    END LOOP;

    RETURN v_clob;
END BASE64_B2C;

/*------------------------------------------------------------------------------
-- 개체명 : BASE64_C2B
-- 생성일 : 2010-03-22 오후 3:03:32
-- 최종수정일 : 2010-03-22 오후 3:03:39
-- 상태 : VALID
------------------------------------------------------------------------------*/
CREATE OR REPLACE FUNCTION BASE64_C2B(C IN CLOB) RETURN BLOB
IS
	v_blob				BLOB;
	v_offset			INTEGER;
	v_buffer_varchar	VARCHAR2(4096);
	v_buffer_raw		RAW(4096);
	v_buffer_size		BINARY_INTEGER := 4096;
BEGIN
	IF c IS NULL
	THEN
        RETURN NULL;
    END IF;

    DBMS_LOB.createTemporary(v_blob, TRUE);
    v_offset := 1;

    LOOP
        BEGIN
            DBMS_LOB.READ(c, v_buffer_size, v_offset, v_buffer_varchar);
            EXCEPTION
                WHEN NO_DATA_FOUND THEN
            EXIT;
        END;

        v_buffer_raw := UTL_ENCODE.BASE64_DECODE(UTL_RAW.CAST_TO_RAW(v_buffer_varchar));
        dbms_lob.writeAppend(v_blob, UTL_RAW.LENGTH(v_buffer_raw), v_buffer_raw);
        v_offset := v_offset + v_buffer_size;
    END LOOP;

    RETURN v_blob;

END BASE64_C2B;