Шифрование и дешифрование от Oracle к PostgreSQL

Question

Подскажите, пожалуйста, как мне этого добиться (от Oracle до Postgres).

Для этих следующих функций.

ENCRYPTION

PROCEDURE sp_encrypt
(
    i_ustring   IN  VARCHAR2,
    o_estring   OUT VARCHAR2
)
IS
    crypt_part  VARCHAR2(10);
BEGIN
    o_estring := NULL;
    FOR pos in 1..length(i_ustring)
        loop
            crypt_part := NULL;
            crypt_part := utl_raw.bit_xor(HEXTORAW(utl_raw.cast_to_raw(SUBSTR(i_ustring,pos,1))),HEXTORAW(fn_num_to_hex(MOD(pos,256))));
            if length(crypt_part)<2
                then
                    crypt_part := '0'||crypt_part;
            end if;
            o_estring := o_estring||crypt_part;
        end loop;
        o_estring :=  utl_raw.cast_to_varchar2(utl_raw.reverse(utl_raw.cast_to_raw(o_estring)));
END sp_encrypt;

DECRYPTION

PROCEDURE sp_decrypt
(
    i_estring   IN  VARCHAR2,
    o_ustring   OUT VARCHAR2
)
IS
    estring     VARCHAR2(32767);
    crypt_part  VARCHAR2(10);
    pos         NUMBER;
BEGIN
    estring :=  utl_raw.cast_to_varchar2(utl_raw.reverse(utl_raw.cast_to_raw(i_estring)));
    pos := 1;
    FOR cnt in 1..length(estring)/2
        loop
            crypt_part := NULL;
            crypt_part := CHR(fn_hex_to_num(utl_raw.bit_xor(HEXTORAW(SUBSTR(estring,pos,2)),HEXTORAW(fn_num_to_hex(MOD(NVL(LENGTH(o_ustring),0)+1,256))))));
            o_ustring := o_ustring||crypt_part;
            pos:=pos+2;
        end loop;
END sp_decrypt;