智能卡协议ISO7816
对于智能卡来说，主要是ATR与PPS的获取，其他的信息，就要参照具体卡的制造商来通信了。
Structures and content
1，atr的整体构成：最多不超过32个字节
A reset operation results in the answer from the card c**isting of the initial character TS followed by at most 32 characters in the following order:- T0 ................... Format character (Mandatory) - TAi, TBi, TCi, TDi ... Interface characters(Optional) - T1, T2, ... ,TK ...... Historical characters (Optional) - TCK .................. Check character (Conditional)Reset | | _________________________________________ _______ _________ | | | | | | | | | | | | | | | | | '-->| TS| T0|TA1|TB1|TC1|TD1|TA2|TB2|TC2|TD2| ......... | T1| ... | TK|TCK| |___|___|___|___|___|___|___|___|___|___|_ _|___|_ _|__ |___| TS: Initial character TO: Format character TAi : Interface character [ codes FI,DI ] TBi : Interface character [ codes II,PI1 ] TCi : Interface character [ codes N ] TDi : Interface character [ codes Yi+1, T ] T1, ... , TK : Historical characters (max,15) TCK : Check characterFigure: General configuration of the Answer to Reset2，atr的第一个字节TS，也就是atr的位说明：The two possible values of TS (ten c**ecutive bits from start to bi and corresponding hexadecimal value) are
- Inverse convention : (Z)ZZAAAAAZ where logic level ONE is A, ba is b8 (msb is first), equal to $3F when decoded by inverse convention.
- Direct convention : (Z)ZZAZZZAAZ where logic level ONE is Z, ba is b1 (lsb first), equal to $3B when decoded by direct convention.
Startbabbbcbdbebfbgbhbi Z ____ _______ ___________ ______ | | | | | Z Z Z | | | | (Z)| A | Z Z | A | or | | Z(Z) A |___| |___|_A___A___A_|___|___| Figure: Initial character TS上面是对TS也就是atr的第一个字节atr的说明：当TS的逻辑电平时A时，atr=3B，正向传输；当TS的逻辑电平时Z时，atr=3F，反向传输。 3，atr的第二个字节atr，也就是T0的位说明：主要是其中的b1-b4组成的K，来说明历史字节数。这4个为最大可以表示15，这个K表明在这个字节后面还跟有K个历史字节，除开这K个历史字节后才是真正的atr数据。Format character T0 ------------------- The T0 character contains two parts: - The most significant half byte (b5, b6, b7, b8) is named Y1 and indicates with a logic level ONE the presence of subsequent characters TA1, TB1, TC1, TD1 respectively.
- The least significant half byte (b4 to b1) is named K and indicates the number (0 to 15) of historical characters.
,----,----,----,----,----,----,----,----, | b8 | b7 | b6 | b5 | b4 | b3 | b2 | b1 | '----'----'----'----'----'----'----'----' :<------- Y1 ------>:<-------- K ------>: Y1 : indicator for the presence of the interface characters TA1 is transmitted when b5=1 TB1 is transmitted when b6=1 TC1 is transmitted when b7=1 TD1 is transmitted when b8=1 K : number of hitorical characters Figure : Informati** provided by T0 4，协议类型说明字节：TAi, TBi, TCi (i=1, 2, 3, ... ) indicate the protocol parameters 此段代码就是根据上面的协议来解析atr数据的，可以仔细参考nRet = eis_smartcard_reset(index, atr); atr_len += 2; //CLA/INS if (atr & 0x0f0) { if (atr & 0x80) { // TD1 is transmitted when b8=1 td1_flag = 1; atr_len ++; } else { me->irdtV3Mgr->vdMgr->sc_info.protocol = IRDETO_V3_SC_T0; } if (atr & 0x40) { atr_len ++; } if (atr & 0x20) { atr_len ++; } if (atr & 0x10) { atr_len ++; } } if (td1_flag) {//TD1---T>0, TCK if ((atr & 0x0f) == 0) { me->irdtV3Mgr->vdMgr->sc_info.protocol = IRDETO_V3_SC_T0; } else if ((atr & 0x0f) == 1) { me->irdtV3Mgr->vdMgr->sc_info.protocol = IRDETO_V3_SC_T1; } else if ((atr & 0x0f) == 14) { me->irdtV3Mgr->vdMgr->sc_info.protocol = IRDETO_V3_SC_T14; } atr_len ++; } atr_len += (atr & 0x0f);
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