> For the complete documentation index, see [llms.txt](https://developer.magtek.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.magtek.com/api-and-command-reference/scra-dynafamily-programmers-manual/data-types-and-shared-tlv-data-objects/emv-configuration-ca-public-keys-file-type.md).

# EMV Configuration CA Public Keys File Type

The host can load this file type to control the behavior of the device’s EMV contact and contactless kernels when the device should support Offline Data Authentication (ODA). Populate all values from information provided by each payment brand that should be supported by the device. The host can load this file using **Start Send File to Device (Unsecured) - Command 0xD812**.

MagTek provides tools that allow these settings to be loaded using a Microsoft Excel spreadsheet in xlsx format for more convenient authoring, review, and change tracking. For a reference sample spreadsheet,

contact MagTek Support Services. The MagTek tools expect the spreadsheet to be formatted format as shown in **Table XX**. Each CA Key to be supported is defined in a tab of the Excel file.

## **Table EMVCKF-1 - EMV Configuration CA Keys File Type**

<table><thead><tr><th width="115.18182373046875">Tag</th><th width="95.3636474609375">Len</th><th>Value / Description</th><th width="74.9090576171875">Typ</th><th width="75.272705078125">Req</th><th>Example</th></tr></thead><tbody><tr><td>DFDF79</td><td>05</td><td>Registered Application ID (RID)</td><td>B</td><td>R</td><td>A0 00 00 00 04</td></tr><tr><td>DFDF7A</td><td>01</td><td>CA Public Key Index</td><td>B</td><td>R</td><td>05</td></tr><tr><td>DFDF7B</td><td>var</td><td>CA Public key Modulus</td><td>B</td><td>R</td><td>B8 04 8A … D5 97</td></tr><tr><td>DFDF7C</td><td>01 or 03</td><td>CA Public Key Exponent</td><td>B</td><td>R</td><td>03</td></tr><tr><td>DFDF7D</td><td>14</td><td>CA Public Key Checksum</td><td>B</td><td>R</td><td>EB FA 0D 5D 06 D8 CE 70 2D A3 EA E8 90 70 1D 45 E2 74 C8 45</td></tr></tbody></table>

The MagTek tool converts the spreadsheet data into the format shown in **CA Keys Raw Format.**

## **Table EMVCKF-2 - CA Keys Raw Format**

| CA Keys Raw Format                                                    |
| --------------------------------------------------------------------- |
| RID (5 Bytes) As defined by the payment brand.                        |
| Index (1 Byte) As defined by the payment brand.                       |
| <p>Exponent Length (1 Byte)</p><ul><li>0x01</li><li>0x03</li></ul>    |
| Key Length (1 Byte), Max of 248 bytes per EMVCo specifications        |
| <p>Exponent (1 or 3 Bytes)</p><ul><li>0x03</li><li>0x010001</li></ul> |
| Modulus As defined by the payment brand.                              |
| Additional CA Keys, repeating from RID through Modulus, as needed.    |
| SHA-1 hash of all data in the file                                    |


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