Protocol Steps for Chip Authentication

Functions
BUF_MEM *	CA_STEP1_get_pubkey (const EAC_CTX *ctx)
	Get the PICC's encoded public key. More...
BUF_MEM *	CA_STEP2_get_eph_pubkey (const EAC_CTX *ctx)
	Get the PCD's ephemeral public key (generated in TA step 3) More...
int	CA_STEP3_check_pcd_pubkey (const EAC_CTX *ctx, const BUF_MEM *comp_pubkey, const BUF_MEM *pubkey)
	Check whether the public key matches the compressed public key previously received in TA. More...
int	CA_STEP4_compute_shared_secret (const EAC_CTX *ctx, const BUF_MEM *pubkey)
	Compute the shared secret using the PICC's static key pair and the PCD's ephemeral key pair. More...
int	CA_STEP5_derive_keys (const EAC_CTX *ctx, const BUF_MEM *pub, BUF_MEM **nonce, BUF_MEM **token)
	Derives the PICC's encryption and authentication keys. More...
int	CA_STEP6_derive_keys (EAC_CTX *ctx, const BUF_MEM *nonce, const BUF_MEM *token)
	Derives the PCD's encryption and authentication keys. More...

Detailed Description

Function Documentation

CA_STEP1_get_pubkey()

BUF_MEM* CA_STEP1_get_pubkey

(

const EAC_CTX *

ctx

)

Get the PICC's encoded public key.

Parameters

[in]

ctx

EAC context

Returns

Encoded public key or NULL in case of an error

See also

CA's Protocol Specification

CA_STEP2_get_eph_pubkey()

BUF_MEM* CA_STEP2_get_eph_pubkey

(

const EAC_CTX *

ctx

)

Get the PCD's ephemeral public key (generated in TA step 3)

Parameters

[in]

ctx

EAC context

Returns

Public key or NULL in case of an error

See also

CA's Protocol Specification

CA_STEP3_check_pcd_pubkey()

int CA_STEP3_check_pcd_pubkey	(	const EAC_CTX *	ctx,
		const BUF_MEM *	comp_pubkey,
		const BUF_MEM *	pubkey
	)

Check whether the public key matches the compressed public key previously received in TA.

Parameters

[in]	ctx	EAC context
[in]	comp_pubkey	Compressed public key (received in TA step 3)
[in]	pubkey	Uncompressed public key (received in CA step 2)

Returns

1 if the keys match, 0 if they don't or -1 in case of an error

See also

CA's Protocol Specification

CA_STEP4_compute_shared_secret()

int CA_STEP4_compute_shared_secret	(	const EAC_CTX *	ctx,
		const BUF_MEM *	pubkey
	)

Compute the shared secret using the PICC's static key pair and the PCD's ephemeral key pair.

Parameters

[in,out]	ctx	EAC context. The secret is saved in ctx.
[in]	pubkey	Public key from the other party

Returns

1 on success or 0 in case of an error

See also

CA_get_pubkey() extracts the PICC's public key from an EF.CardSecurity

CA's Protocol Specification

CA_STEP5_derive_keys()

int CA_STEP5_derive_keys	(	const EAC_CTX *	ctx,
		const BUF_MEM *	pub,
		BUF_MEM **	nonce,
		BUF_MEM **	token
	)

Derives the PICC's encryption and authentication keys.

Parameters

[in,out]	ctx	EAC context. The keys are saved in ctx.
[in]	pub	PCD's ephemeral public key
[out]	nonce	Generated nonce
[out]	token	Authentication token

Returns

1 on success or 0 in case of an error

See also

CA's Protocol Specification

CA_STEP6_derive_keys()

int CA_STEP6_derive_keys	(	EAC_CTX *	ctx,
		const BUF_MEM *	nonce,
		const BUF_MEM *	token
	)

Derives the PCD's encryption and authentication keys.

Parameters

[in,out]	ctx	EAC context. The keys are saved in ctx.
[in]	nonce	PICC's generated nonce
[in]	token	PICC's authentication token to verify

Returns

1 on success or 0 in case of an error

See also

CA's Protocol Specification