从 EMV 响应中获取数据

Question

I tried to translate an EMV response of my card details. For that, I used

https://github.com/binaryfoo/emv-bertlv to get data.

below you can see the output:

[6F (FCI template)] 8407A0000000031010A52F500B56495341204352454449548701015F...1A02
      [84 (dedicated file name)] A0000000031010
      [A5 (FCI proprietary template)] 500B56495341204352454449548701015F2D086573656E707466729F...1A02
        [50 (application label)] VISA CREDIT
        [87 (application priority indicator)] 01
        [5F2D (language preference)] esenptfr
        [9F12 (application preferred name)] CREDITO
        [9F11 (issuer code table index)] 01
        [9F38 (PDOL - Processing data object list)] 9F1A02
I/System.out:       9F1A (terminal country code) 2 bytes 

How can I get application label value using this output?

Answer 1

If I understand your question correctly, you want to understand how they parsed your string to that form. For that, you need to understand EMV parsing following TLV (Tag Length(in hex) and Value ) format. Sometimes tags are grouped under a template. Follow this answer for more details where I have explained in further detail with references from EMVCo specs.