The dwMaxIFSD field is a number value from the USB CCID descriptor: Indicates the maximum IFSD supported by CCID for protocol T=1.
| dwMaxIFSD | # | % |
|---|---|---|
| 254 | 176 | 69.29 % |
| 252 | 34 | 13.39 % |
| 247 | 16 | 6.30 % |
| 0 | 12 | 4.72 % |
| 1024 | 4 | 1.57 % |
| 256 | 3 | 1.18 % |
| 1400 | 2 | 0.79 % |
| 1041 | 1 | 0.39 % |
| 123 | 1 | 0.39 % |
| 2048 | 1 | 0.39 % |
| 240 | 1 | 0.39 % |
| 248 | 1 | 0.39 % |
| 49 | 1 | 0.39 % |
| 64 | 1 | 0.39 % |
Some values may look strange or bogus:
- 0 is used by 5% of readers. It is not a bug for a ICCD device with a T=0 card inside because dwMaxIFSD is only used with a T=1 card.
Readers with dwMaxIFSD = 0 are:- ATMEL AT91SC192192CT-USB ICCD reader
- ATMEL AT98SC032CT-USB
- ATMEL VaultIC420 Smart Object
- ATMEL VaultIC440
- ATMEL VaultIC460
- Gemalto Hybrid Smartcard Reader
- IID AT90S064 CCID READER
- INSIDE Secure VaultIC 405 Smart Object
- INSIDE Secure VaultIC 441 Smart Object
- Inside Secure VaultIC 420 Smart Object
- Inside Secure VaultIC 440 Smart Object
- Inside Secure VaultIC 460 Smart Object
- MYSMART MySMART PAD V2.0
- SchlumbergerSema SchlumbergerSema Cyberflex Access
- SecuTech SecuTech Token
- TianYu CCID Key TianYu CCID SmartKey
- The maximum value for dwMaxIFSD is dwMaxCCIDMessageLength - 10.
Readers with dwMaxIFSD > dwMaxCCIDMessageLength - 10, so bogus readers, are:
- Aktiv Co., ProgramPark Rutoken Magistra
- CCB eSafeLD
- Feitian bR301
- Free Software Initiative of Japan Gnuk
- Gemalto PDT
- Giesecke & Devrient GmbH Star Sign Card Token 550 (ICCD)
- OCS ID-One Cosmo Card USB Smart Chip Device
- Philips Semiconductors JCOP41V221
- Philips Semiconductors SmartMX Sample
- Planeta RC700-NFC CCID
- Yubico Yubikey NEO CCID
- Yubico Yubikey NEO OTP+CCID