pb加密转换成C#

本来想把PB 的函数封装成COM组件调用,结果怎么都搞不定,只能讲代码搞出来换种语言实现了.

string s_ret
integer i_first,i_second,i_third,i_fourth
integer by4,i,reallen
long i_total
string is_key
string is_base64
string EncMap[ to ]
int DecMap[ to ]
integer by3
long i_len

is_base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
is_base64 = is_base64 + "abcdefghijklmnopqrstuvwxyz"
is_base64 = is_base64 + ""
is_base64 = is_base64 + "+/"
for i =  to
    EncMap[i]=mid(is_base64,i+,)
next
for i =  to
    DecMap[asc(EncMap[i])] = i
next
choose case a_type
    case //加密
        s_ret = ""
        if len(a_text)=  then
            return s_ret
        end if
        by3=len(a_text) - mod(len(a_text),)
        i=
        do while i<= by3
            i_first = asc(mid(a_text,i + ,))
            i_second = asc(mid(a_text, i + ,))
            i_third = asc(mid(a_text,i + ,))
            s_ret = s_ret + encmap[i_first / ]
            s_ret = s_ret + encmap[mod(i_first , ) *  + i_second /  ]
            s_ret = s_ret + encmap[mod(i_second , ) *  + i_third /  ]
            s_ret = s_ret + encmap[mod(i_third , )]
            i = i +
        loop
        if i <= len(a_text) then
            i_first = asc(mid(a_text, i + , ))
            if mod(len(a_text), )= then
                i_second =asc(mid(a_text,i+,))
                s_ret = s_ret + encmap[i_first / ]
                s_ret = s_ret + encmap[mod(i_first , ) *  + i_second /  ]
                s_ret = s_ret + encmap[mod(i_second , ) *  ]
                s_ret = s_ret + "="
            else
                s_ret = s_ret + encmap[i_first / ]
                s_ret = s_ret + encmap[mod(i_first,) * ]
                s_ret = s_ret + "=="
            end if
        end if
        i_len = len(s_ret)
        s_ret = left(string(i_len+),) + s_ret

    case //解密
        if len(a_text)=  then
            s_ret = ""
            return s_ret
        end if
        a_text=right(a_text,len(a_text)-)
        reallen = len(a_text)
        do while mid(a_text,reallen,) = "="
            reallen = reallen -
        loop
        by4=reallen - mod(reallen,)
        i=
        do while i<= by4
            i_first = decmap[asc(mid(a_text,i + ,))]
            i_second = decmap[asc(mid(a_text, i + ,))]
            i_third = decmap[asc(mid(a_text,i + ,))]
            i_fourth = decmap[asc(mid(a_text,i + ,))]
            s_ret = s_ret + char(i_first *  + i_second / )
            s_ret = s_ret + char(mod(i_second,) *  + i_third /  )
            if mod(i_third,) *  + i_fourth <>  then
                s_ret = s_ret + char(mod(i_third,) *  + i_fourth)
            end if
            i = i +
        loop
        if i<= reallen then     //只可能是xx==或xxx=两种形式有效
            if mod(reallen,) =  then    //xx==形式
                i_first = decmap[asc(mid(a_text,i + ,))]
                i_second = decmap[asc(mid(a_text, i + ,))]
                s_ret = s_ret + char(i_first *  + i_second / )
                s_ret = s_ret + char(mod(i_second,) * )
            else
                i_first = decmap[asc(mid(a_text,i + ,))]
                i_second = decmap[asc(mid(a_text, i + ,))]
                i_third = decmap[asc(mid(a_text,i + ,))]
                s_ret = s_ret + char(i_first *  + i_second / )
                s_ret = s_ret + char(mod(i_second,) *  + i_third /  )
            end if
        end if

end choose
return s_ret 

        public static string right(string s1, int str)
        {
            return s1.Substring(s1.Trim().Length - str, str);
        }

        public static string left(string s1, int str)
        {
            return s1.Substring( , str);
        }

        public static char mid(string s1, int str, int len)
        {
            return s1.Substring(str, len).ToArray()[];
        }

        public static int asc(char c1)
         {
             return(int)c1;
         }

        public static int mod(int x,int y)
        {
            return x % y;
        }

        public static int len(string s1)
        {
            return s1.Length;
        }

        public static string encrypt(string a_text, string type = "")
        {
            string s_ret;
            int i_first, i_second, i_third, i_fourth;
            int by4, i, reallen;
            long i_total;
            string is_key;
            string is_base64;
            char[] encmap = new char[];
            int[] decmap = new int[];
            int by3 = ;
            long i_len;

            is_base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
            is_base64 = is_base64 + "abcdefghijklmnopqrstuvwxyz";
            is_base64 = is_base64 + "";
            is_base64 = is_base64 + "+/";

            char[] tk = is_base64.ToCharArray();

            for (i = ; i <= ; i++)
            {
                encmap[i] = tk[i];
            }

            for (i = ; i <= ; i++)
            {
                int tp = (int)asc(encmap[i]);
                decmap[tp] = i;
            }

            s_ret = "";
            if (a_text.Trim() == "")
            {
                return s_ret;
            }

            if (type == "")
            {
                by3 = a_text.Length - (a_text.Length % );

                i = ;
                while (i < by3)
                {
                    i_first = asc(mid(a_text, i + , ));

                    i_second = asc(mid(a_text, i + , ));
                    i_third = asc(mid(a_text, i + , ));
                    s_ret = s_ret + encmap[i_first / ];
                    s_ret = s_ret + encmap[mod(i_first, ) *  + i_second / ];
                    s_ret = s_ret + encmap[mod(i_second, ) *  + i_third / ];
                    s_ret = s_ret + encmap[mod(i_third, )];
                    i = i + ;
                }
                if (i < len(a_text))
                {
                    i_first = asc(mid(a_text, i + , ));
                    if ((a_text.Length % ) == )
                    {
                        i_second = asc(mid(a_text, i + , ));
                        s_ret = s_ret + encmap[i_first / ];
                        s_ret = s_ret + encmap[mod(i_first, ) *  + i_second / ];
                        s_ret = s_ret + encmap[mod(i_second, ) * ];
                        s_ret = s_ret + "=";
                    }
                    else
                    {
                        s_ret = s_ret + encmap[i_first / ];
                        s_ret = s_ret + encmap[mod(i_first, ) * ];
                        s_ret = s_ret + "==";
                    }
                }
                i_len = len(s_ret);
                s_ret = left((i_len + ).ToString(), ) + s_ret;
            }
            else
            {

                a_text = right(a_text, len(a_text) - );
                reallen = len(a_text);
                while (mid(a_text, reallen - , ) == '=')
                {
                    reallen = reallen - ;
                }

                by4 = reallen - mod(reallen, );

                i = ;

                while (i < by4)
                {
                    i_first = decmap[asc(mid(a_text, i + , ))];
                    i_second = decmap[asc(mid(a_text, i + , ))];
                    i_third = decmap[asc(mid(a_text, i + , ))];
                    i_fourth = decmap[asc(mid(a_text, i + , ))];
                    s_ret = s_ret + (char)(i_first *  + i_second / );
                    s_ret = s_ret + (char)(mod(i_second, ) *  + i_third / );
                    if (mod(i_third, ) *  + i_fourth != )
                    {
                        s_ret = s_ret + (char)(mod(i_third, ) *  + i_fourth);
                    }
                    i = i + ;
                }
                if (i < reallen)
                {
                    //只可能是xx==或xxx=两种形式有效
                    if (mod(reallen, ) == )    //xx==形式
                    {
                        i_first = decmap[asc(mid(a_text, i + , ))];
                        i_second = decmap[asc(mid(a_text, i + , ))];
                        s_ret = s_ret + (char)(i_first *  + i_second / );
                        s_ret = s_ret + (char)(mod(i_second, ) * );
                    }
                    else
                    {
                        i_first = decmap[asc(mid(a_text, i + , ))];
                        i_second = decmap[asc(mid(a_text, i + , ))];
                        i_third = decmap[asc(mid(a_text, i + , ))];
                        s_ret = s_ret + (char)(i_first *  + i_second / );
                        s_ret = s_ret + (char)(mod(i_second, ) *  + i_third / );
                    }
                }
            }
            return s_ret;
        }