Documentation
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Overview ¶
Package desfire decodes Mifare DESFire Application Identifiers (AIDs) — the 3-byte values returned by the DESFire GetApplicationIDs command that identify each application stored on the card. Pure offline parser; no transport, no hardware.
Wrap-vs-native judgement: the DESFire AID format is a public NXP specification (DESFire reference, AN10833 for the MAD extension). The walker is a 3-byte lookup with a per-function- code category table. Wrapping a FAP for this would require an SD-card install + a firmware-fork dependency for a pure lookup. Native delivers offline analysis — operators paste a DESFire AID from a Flipper / Proxmark / pcsc_scan "list applications" output and identify the application without re-presenting the card.
Pairs with the existing NFC decoders (nfc_iso14443a_identify for the card-type identification; mifare_classic_decode for the Classic emulation path; nfc_emv_decode for EMV BER-TLV inside DESFire applications).
What this package covers:
- 3-byte AID decode (big-endian rendering matches the form printed in NXP application notes and operator tools)
- MAD-style AID detection (high nibble 0xF — MIFARE Application Directory format)
- Function code category lookup for MAD AIDs per NXP AN10833 / ISO 7816-5 (transit / banking / retail / loyalty / access / parking / membership / etc.)
- Well-known AID name catalog (MIFARE Classic emulation, OV-chipkaart, HID iCLASS-SE, ePassport, etc.)
- Special-value detection (empty 0x000000, wildcard 0xFFFFFF, MIFARE Classic emulation 0xF40000)
What this package does NOT cover (deliberately out of scope):
- DESFire application key derivation (needs the card master key)
- DESFire file structure decode (separate Spec when a caller materialises with file-listing output)
- Application key file decryption (AES-128 / 3K3DES)
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type AID ¶
type AID struct {
// Raw is the 24-bit value (high byte = byte 0 = canonical
// rendering).
Raw int `json:"raw"`
// Hex is the operator-facing 6-char uppercase form ("F40000").
Hex string `json:"hex"`
// Special is "empty" (000000), "mifare_classic" (F40000),
// "wildcard" (FFFFFF), or "" for normal AIDs.
Special string `json:"special,omitempty"`
// MADFormatted reports whether the AID uses the MIFARE
// Application Directory format (high nibble 0xF).
MADFormatted bool `json:"mad_formatted"`
// FunctionCode is the 12-bit MAD function code (bits 23..12
// when MAD-formatted). 0 for non-MAD AIDs.
FunctionCode int `json:"function_code,omitempty"`
FunctionCodeHex string `json:"function_code_hex,omitempty"`
// Category is the documented MAD category name when the
// function code matches a known range, "" otherwise.
Category string `json:"category,omitempty"`
// ApplicationName is the well-known application name when
// the full AID is in our catalog.
ApplicationName string `json:"application_name,omitempty"`
// VendorSubID is the 12-bit sub-identifier (bits 11..0)
// when the AID is MAD-formatted. The MAD allocates this
// sub-space to individual operators within a category.
VendorSubID int `json:"vendor_sub_id,omitempty"`
VendorSubIDHex string `json:"vendor_sub_id_hex,omitempty"`
}
AID is the decoded view of a 3-byte DESFire Application Identifier.
func Decode ¶
Decode parses a hex-encoded 3-byte DESFire AID. Accepts 6 hex chars with optional 0x prefix and ':' / '-' / '_' / whitespace separators.
func DecodeUint24 ¶
DecodeUint24 is the integer-input variant of Decode. Takes the bottom 24 bits of the input (high byte ignored).
Source Files