The PDF417 barcode is 720 bytes. First 4 bytes indicate the version of barcode.
V1: 01 e1 02 45
V2: 01 9b 09 45
Next two bytes are zero. Remaining 714 bytes form 6 blocks - 5 blocks of 128, 1 block of 74.
Different keys are used depending on version and and block size.
openssl rsautl -inkey _128.key -pubin -in block_1.enc -raw > block_1.bin