Otfad

Data Structures
struct	otfad_kek_t
	Format of OTFAD key wrap key (KEK). More...
struct	keyblob_t
	Key Blob format. More...
struct	keyblob_data_t

Enumerations
enum	_otfad_driver_errors {   kStatus_OtfadSecurityViolation = MAKE_STATUS(kStatusGroup_OTFADDriver, 0),   kStatus_OtfadLogicallyDisabled = MAKE_STATUS(kStatusGroup_OTFADDriver, 1),   kStatus_OtfadInvalidKey = MAKE_STATUS(kStatusGroup_OTFADDriver, 2),   kStatus_OtfadInvalidKeyBlob = MAKE_STATUS(kStatusGroup_OTFADDriver, 3) }
	OTFAD Driver status codes.
enum	_constants {   kAesKeySizeBytes = 16,   kCtrSizeBytes = 8,   kCrc32SizeBytes = 32,   kNumKeyBlobs = 4,   kKeyBlobSizeBytes = 64,   kKeyBlobArraySizeBytes = kKeyBlobSizeBytes * kNumKeyBlobs }
	Constants. More...

Functions
status_t	otfad_init (uint32_t instance, const uint8_t *keyBlobs, const otfad_kek_t *kek)
	Initialize. More...
static void	program_contexts (OTFAD_Type *baseAddr, uint8_t *keyBlobs, uint32_t *kek)
	Program context regiters with information from key blobs. More...
static bool	validate_crc (const keyblob_t *keyBlob)
	Validate CRC32 in key blob. More...

Variables
const uint32_t	g_otfadBaseAddr [] = OTFAD_BASE_ADDRS
	Instance base addresses.

Usage Information

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Data Structure Documentation

struct otfad_kek_t

Format of OTFAD key wrap key (KEK).

The four consecutive little-endian memory-mapped registers provide 128 bits of key storage.

Data Fields
uint32_t	keyWord0	Word0: KEY[31:0][A03, A02, A01, A00].
uint32_t	keyWord1	Word1: KEY[31:0][A07, A06, A05, A04].
uint32_t	keyWord2	Word2: KEY[31:0][A11, A10, A09, A08].
uint32_t	keyWord3	Word3: KEY[31:0][A15, A14, A13, A12].

struct keyblob_t

Key Blob format.

Data Fields
uint8_t	ctr[kCtrSizeBytes]
uint32_t	endaddr
uint8_t	expanded_wrap_data[8]
uint8_t	key[kAesKeySizeBytes]
uint32_t	key_blob_crc32
uint32_t	srtaddr
uint8_t	unused_filler[16]
uint32_t	zero_fill

struct keyblob_data_t

Collaboration diagram for keyblob_data_t:

Data Fields
uint8_t	ivHeader[8]
keyblob_t	keyBlob

Enumeration Type Documentation

enum _constants

Constants.

Enumerator
kAesKeySizeBytes	Number of bytes in AES-128 key.
kCtrSizeBytes	Number of bytes in Ctr.
kCrc32SizeBytes	Number of bytes covered by CRC32.
kNumKeyBlobs	Number of key blobs.
kKeyBlobSizeBytes	Key blob size in bytes.
kKeyBlobArraySizeBytes	Key blob array size in bytes.

Function Documentation

status_t otfad_init	(	uint32_t	instance,
		const uint8_t *	keyBlobs,
		const otfad_kek_t *	kek
	)

Initialize.

If OTFAD KEY in the SIM module is invalid, or the key blobs are invalid, then the OTFAD will be initialized to bypass mode (no decryption). Otherwise, keyBlobs will be unwrapped and programmed into the OTFAD context registers.

Parameters

instance	Module instance
keyBlobs	Pointer to array of 4 key blobs
kek	Pointer to OTFAD Key Encryption Key (KEK)

Return values

kStatus_OtfadLogicallyDisabled	OTFAD is disabled
kStatus_OtfadSecurityViolation	Security violation detectd
kStatus_Success	OTFAD has been initialized

static void program_contexts ( OTFAD_Type *  baseAddr, uint8_t *  keyBlobs, uint32_t *  kek  )

static

Program context regiters with information from key blobs.

Key blobs are unwrapped first. Each blob is validated with CRC32.

Parameters

baseAddr	OTFAD module base address
keyBlobs	pointer to array of 4 key blobs
kek	KeK words

bool validate_crc ( const keyblob_t *  keyBlob )

static

Validate CRC32 in key blob.

Parameters

keyBlob

Pointer to key blob

Returns

True if CRC matches, False otherwise