6 - Magnetic Stripe Card Data Sent from Device to Host (MSR Only | Keypad Entry Only)
eDynamo| Secure Card Reader Authenticator | Programmer’s Manual (COMMANDS)
Page 49 of 245 (
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6.9
MagnePrint Data Length (HID | GATT | SLIP)
This one-byte value indicates the number of bytes in the
always a multiple of 8 bytes in length. This value is zero if there is no MagnePrint data. After the
Encrypted MagnePrint data is decrypted, there may be fewer bytes of MagnePrint data than indicated by
this value. The number of bytes of decrypted MagnePrint data is indicated by
If the device is set to a security level below
, it uses the current value of
to determine the behavior of this value.
Format
Where to Find Value
HID
Usage 0x2B
Streaming
N/A
TLV
N/A
GATT/SLIP
Offset 348
6.10
MagnePrint Absolute Data Length (HID | TLV | GATT | SLIP)
This one-byte value indicates the number of usable bytes in
decryption.
If the device is set to a security level below
, it uses the current value of
to determine the behavior of this value.
Format
Where to Find Value
HID
Usage 0x54
Streaming
N/A
TLV
Data Object 8263
GATT/SLIP
Offset 855
6.11
Encrypted MagnePrint Data
This value contains Encrypted MagnePrint data, which when decrypted generally yields a 54-byte value.
The least significant bit of the first byte of data in the decrypted value corresponds to the first bit of
MagnePrint data.
If the device is set to a security level below
, it uses the current value of
to determine the behavior of this value.
To derive a decrypted MagnePrint value to authenticate a card, the host should do the following:
1)
If the device transmitted a
, truncate the data to that length to strip out
protocol padding and yield a decryptable data block.
2)
Decrypt the data block.
3)
If the device transmitted a
MagnePrint Absolute Data Length (HID | TLV | GATT | SLIP)
truncate the data to that length to yield the MagnePrint data.
