Functions

General Description

Typedefs
typedef cy_en_cryptolite_status_t(*	cy_cryptolite_ed25519_sha512_init_t) (void *context)
	Pointer to a sha initialization function.
typedef cy_en_cryptolite_status_t(*	cy_cryptolite_ed25519_sha512_update_t) (void *context, uint8_t const *input, uint32_t inputSize)
	Pointer to a sha update function.
typedef cy_en_cryptolite_status_t(*	cy_cryptolite_ed25519_sha512_start_t) (void *context)
	Pointer to a sha start function.
typedef cy_en_cryptolite_status_t(*	cy_cryptolite_ed25519_sha512_finish_t) (void *context, uint8_t *output)
	Pointer to a sha output function.
typedef cy_en_cryptolite_status_t(*	cy_cryptolite_ed25519_sha512_free_t) (void *context)
	Pointer to a sha deinitialization function.

Functions
cy_en_cryptolite_status_t	Cy_Cryptolite_ECC_Init (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, cy_stc_cryptolite_ecc_buffer_t *eccBuffer)
	Init ECC Context. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ECC_Free (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext)
	Clean up ECC Context. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ECC_SignHash (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *hash, uint32_t hashlen, uint8_t *sig, const cy_stc_cryptolite_ecc_key *key, const uint8_t *messageKey)
	Function to generate an ECC signature. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ECC_VerifyHash (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *sig, uint32_t siglen, const uint8_t *hash, uint32_t hashlen, cy_en_cryptolite_sig_verify_result_t *stat, const cy_stc_cryptolite_ecc_key *key)
	Verify an ECC signature. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ECC_SharedSecret (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, cy_en_cryptolite_ecc_curve_id_t curveID, const uint8_t *privateKey, const cy_stc_cryptolite_ecc_key *key, uint8_t const *sharedSecret)
	Generate a Shared Secret key from one private key and others public key. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_Init (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, cy_stc_cryptolite_ecc_buffer_t *eccBuffer, cy_stc_cryptolite_ed25519_sha512_t *shaFunctions)
	Init ED25519 Context. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_Free (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext)
	Free ED25519 Context. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_Sign (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *hash, uint32_t hashlen, uint8_t *sig, const cy_stc_cryptolite_ecc_key *key, cy_en_cryptolite_eddsa_sig_type_t sigType, const uint8_t *sigctx, uint32_t sigctx_len)
	Sign a message. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_PointMultiplication (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *ecpGX, const uint8_t *ecpGY, const uint8_t *ecpD, uint8_t *ecpQX, uint8_t *ecpQY)
	Edwards 25519 elliptic curve point multiplication in GF(p). More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_PointDecode (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *publicKey, uint8_t *pubKey_x, uint8_t *pubKey_y)
	Decode ED25519 encoded public key in to x and y. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_Verify (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, uint8_t *sig, const uint8_t *hash, uint32_t hashlen, const cy_stc_cryptolite_ecc_key *key, uint32_t *stat, cy_en_cryptolite_eddsa_sig_type_t sigType, const uint8_t *sigctx, uint32_t sigctx_len)
	Verify ED25519 signed message. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_ED25519_MakePublicKey (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *privateKey, cy_stc_cryptolite_ecc_key *publicKey)
	Make a new ED25519 public key. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_EC25519_MakePublicKey (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, const uint8_t *privateKey, cy_stc_cryptolite_ecc_key *publicKey)
	Make a new EC25519 public key. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_EC25519_MakePrivateKey (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, uint8_t *privateKey, cy_func_get_random_data_t GetRandomDataFunc, void *randomDataInfo)
	Make a new EC25519 private key. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_EC25519_PointMultiplication (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_ecdsa_t *cfContext, uint8_t *p_r, const uint8_t *p_x, const uint8_t *p_d)
	EC25519 Elliptic curve point multiplication in GF(p). More...
cy_en_cryptolite_status_t	Cy_Cryptolite_Rsa_Init (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_rsa_t *cfContext, cy_stc_cryptolite_rsa_buffer_t *rsaBuffers)
	Initialize the RSA context. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_Rsa_Proc (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_rsa_t *cfContext, cy_stc_cryptolite_rsa_pub_key_t *key, uint8_t const *message, uint32_t messageSize, uint8_t *processedMessage)
	RSA process algorithm based on the Montgomery algorithm using Barrett reduction. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_Rsa_Coef (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_rsa_t *cfContext, cy_stc_cryptolite_rsa_pub_key_t *key)
	Calculation constant coefficients to speed-up Montgomery algorithm. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_Rsa_Free (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_rsa_t *cfContext)
	Cleanup the RSA context. More...
cy_en_cryptolite_status_t	Cy_Cryptolite_Rsa_Verify (CRYPTOLITE_Type *base, cy_stc_cryptolite_context_rsa_t *cfContext, cy_en_cryptolite_sig_verify_result_t *verResult, cy_en_cryptolite_sha_mode_t digestType, uint8_t const *digest, uint32_t digestLength, uint8_t const *decryptedSignature, uint32_t decryptedSignatureLength)
	RSA verification with checks for content, paddings and signature format. More...

Function Documentation

Cy_Cryptolite_ECC_Init()

cy_en_cryptolite_status_t Cy_Cryptolite_ECC_Init	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		cy_stc_cryptolite_ecc_buffer_t *	eccBuffer
	)

Init ECC Context.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
eccBuffer	The pointer to the cy_stc_cryptolite_ecc_buffer_t.

Returns

status code. See cy_en_cryptolite_status_t.

Function Usage

    cy_en_cryptolite_status_t status = CY_CRYPTOLITE_BAD_PARAMS;
    cy_stc_cryptolite_context_ecdsa_t sig_ctx;
    cy_stc_cryptolite_ecc_key key;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_stc_cryptolite_ecc_buffer_t ecdsa_buf;

    uint8_t ecc_p256_signature[] = {
    0x0f, 0x8c, 0x19, 0xf5, 0xaf, 0xfe, 0xa6, 0xd5, 0x93, 0xa3, 0x3e, 0x17, 0x6a, 0xa5, 0x27, 0x17,
    0xbf, 0xf8, 0xd5, 0x87, 0x51, 0x65, 0xfc, 0x63, 0xe8, 0x0a, 0x2d, 0x65, 0x58, 0x0d, 0x29, 0x57,
    0x89, 0xdb, 0x5f, 0xfb, 0x53, 0x97, 0xba, 0x4c, 0x67, 0x83, 0x4e, 0x27, 0x31, 0xee, 0x26, 0x8e,
    0xa6, 0xf7, 0xe8, 0x38, 0x46, 0xfb, 0xb0, 0x21, 0x45, 0xb3, 0x54, 0x42, 0xdb, 0x18, 0xcf, 0x0b };

    uint8_t hash_256[] =  {
    0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea, 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
    0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c, 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad };

    uint8_t ecc_p256_public_key[] = {
    0xde, 0xa5, 0xe4, 0x5d, 0x0e, 0xa3, 0x7f, 0xc5, 0x66, 0x23, 0x2a, 0x50, 0x8f, 0x4a, 0xd2, 0x0e,
    0xa1, 0x3d, 0x47, 0xe4, 0xbf, 0x5f, 0xa4, 0xd5, 0x4a, 0x57, 0xa0, 0xba, 0x01, 0x20, 0x42, 0x08,
    0x70, 0x97, 0x49, 0x6e, 0xfc, 0x58, 0x3f, 0xed, 0x8b, 0x24, 0xa5, 0xb9, 0xbe, 0x9a, 0x51, 0xde,
    0x06, 0x3f, 0x5a, 0x00, 0xa8, 0xb6, 0x98, 0xa1, 0x6f, 0xd7, 0xf2, 0x9b, 0x54, 0x85, 0xf3, 0x20};

    memset(&key, 0, sizeof(key));
    memset(&sig_ctx, 0, sizeof(sig_ctx));

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    key.type = PK_PUBLIC;
    key.curveID = CY_CRYPTOLITE_ECC_ECP_SECP256R1;
    key.pubkey.x = (void *)ecc_p256_public_key;
    key.pubkey.y = (void *)(ecc_p256_public_key +  sizeof(ecc_p256_public_key)/2);

    Cy_Cryptolite_InvertEndianness(key.pubkey.x, sizeof(ecc_p256_public_key)/2);
    Cy_Cryptolite_InvertEndianness(key.pubkey.y, sizeof(ecc_p256_public_key)/2);

    Cy_Cryptolite_InvertEndianness(hash_256, sizeof(hash_256));

    Cy_Cryptolite_InvertEndianness(ecc_p256_signature, sizeof(ecc_p256_signature)/2);
    Cy_Cryptolite_InvertEndianness(ecc_p256_signature + sizeof(ecc_p256_signature)/2, sizeof(ecc_p256_signature)/2);

    status = Cy_Cryptolite_ECC_Init(CRYPTOLITE,&sig_ctx, &ecdsa_buf);

    /* ... check for errors... */

    status = Cy_Cryptolite_ECC_VerifyHash(CRYPTOLITE, &sig_ctx, ecc_p256_signature, sizeof(ecc_p256_signature), hash_256, sizeof(hash_256), &verResult, &key);

    /* ... check for errors... */

    status =  Cy_Cryptolite_ECC_Free(CRYPTOLITE, &sig_ctx);

    /* ... check for errors & verResult to be CY_CRYPTOLITE_SIG_VALID... */

Cy_Cryptolite_ECC_Free()

cy_en_cryptolite_status_t Cy_Cryptolite_ECC_Free	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext
	)

Clean up ECC Context.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.

Returns

status code. See cy_en_cryptolite_status_t.

Function Usage

    cy_en_cryptolite_status_t status = CY_CRYPTOLITE_BAD_PARAMS;
    cy_stc_cryptolite_context_ecdsa_t sig_ctx;
    cy_stc_cryptolite_ecc_key key;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_stc_cryptolite_ecc_buffer_t ecdsa_buf;

    uint8_t ecc_p256_signature[] = {
    0x0f, 0x8c, 0x19, 0xf5, 0xaf, 0xfe, 0xa6, 0xd5, 0x93, 0xa3, 0x3e, 0x17, 0x6a, 0xa5, 0x27, 0x17,
    0xbf, 0xf8, 0xd5, 0x87, 0x51, 0x65, 0xfc, 0x63, 0xe8, 0x0a, 0x2d, 0x65, 0x58, 0x0d, 0x29, 0x57,
    0x89, 0xdb, 0x5f, 0xfb, 0x53, 0x97, 0xba, 0x4c, 0x67, 0x83, 0x4e, 0x27, 0x31, 0xee, 0x26, 0x8e,
    0xa6, 0xf7, 0xe8, 0x38, 0x46, 0xfb, 0xb0, 0x21, 0x45, 0xb3, 0x54, 0x42, 0xdb, 0x18, 0xcf, 0x0b };

    uint8_t hash_256[] =  {
    0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea, 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
    0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c, 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad };

    uint8_t ecc_p256_public_key[] = {
    0xde, 0xa5, 0xe4, 0x5d, 0x0e, 0xa3, 0x7f, 0xc5, 0x66, 0x23, 0x2a, 0x50, 0x8f, 0x4a, 0xd2, 0x0e,
    0xa1, 0x3d, 0x47, 0xe4, 0xbf, 0x5f, 0xa4, 0xd5, 0x4a, 0x57, 0xa0, 0xba, 0x01, 0x20, 0x42, 0x08,
    0x70, 0x97, 0x49, 0x6e, 0xfc, 0x58, 0x3f, 0xed, 0x8b, 0x24, 0xa5, 0xb9, 0xbe, 0x9a, 0x51, 0xde,
    0x06, 0x3f, 0x5a, 0x00, 0xa8, 0xb6, 0x98, 0xa1, 0x6f, 0xd7, 0xf2, 0x9b, 0x54, 0x85, 0xf3, 0x20};

    memset(&key, 0, sizeof(key));
    memset(&sig_ctx, 0, sizeof(sig_ctx));

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    key.type = PK_PUBLIC;
    key.curveID = CY_CRYPTOLITE_ECC_ECP_SECP256R1;
    key.pubkey.x = (void *)ecc_p256_public_key;
    key.pubkey.y = (void *)(ecc_p256_public_key +  sizeof(ecc_p256_public_key)/2);

    Cy_Cryptolite_InvertEndianness(key.pubkey.x, sizeof(ecc_p256_public_key)/2);
    Cy_Cryptolite_InvertEndianness(key.pubkey.y, sizeof(ecc_p256_public_key)/2);

    Cy_Cryptolite_InvertEndianness(hash_256, sizeof(hash_256));

    Cy_Cryptolite_InvertEndianness(ecc_p256_signature, sizeof(ecc_p256_signature)/2);
    Cy_Cryptolite_InvertEndianness(ecc_p256_signature + sizeof(ecc_p256_signature)/2, sizeof(ecc_p256_signature)/2);

    status = Cy_Cryptolite_ECC_Init(CRYPTOLITE,&sig_ctx, &ecdsa_buf);

    /* ... check for errors... */

    status = Cy_Cryptolite_ECC_VerifyHash(CRYPTOLITE, &sig_ctx, ecc_p256_signature, sizeof(ecc_p256_signature), hash_256, sizeof(hash_256), &verResult, &key);

    /* ... check for errors... */

    status =  Cy_Cryptolite_ECC_Free(CRYPTOLITE, &sig_ctx);

    /* ... check for errors & verResult to be CY_CRYPTOLITE_SIG_VALID... */

Cy_Cryptolite_ECC_SignHash()

cy_en_cryptolite_status_t Cy_Cryptolite_ECC_SignHash	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	hash,
		uint32_t	hashlen,
		uint8_t *	sig,
		const cy_stc_cryptolite_ecc_key *	key,
		const uint8_t *	messageKey
	)

Function to generate an ECC signature.

key, hash and messageKey must be in little endian. Cy_Cryptolite_InvertEndianness() function is used for converting the endianness.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
hash	The hash (message digest) to be signed.
hashlen	The length of the hash (octets).
sig	The pointer to the buffer to store the generated signature 'R' followed by 'S'.
key	The private ECC key to sign the hash. See cy_stc_cryptolite_ecc_key.
messageKey	The random number for generating the signature.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_ECC_VerifyHash()

cy_en_cryptolite_status_t Cy_Cryptolite_ECC_VerifyHash	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	sig,
		uint32_t	siglen,
		const uint8_t *	hash,
		uint32_t	hashlen,
		cy_en_cryptolite_sig_verify_result_t *	stat,
		const cy_stc_cryptolite_ecc_key *	key
	)

Verify an ECC signature.

sig, hash and key must be in little endian. Cy_Cryptolite_InvertEndianness() function is used for converting the endianness.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the ecdsa context.
sig	The signature to verify, 'R' followed by 'S'.
siglen	The length of signature.
hash	The hash (message digest) that was signed.
hashlen	The length of the hash (octets).
stat	Result of signature, 0xAAAAAAAA = invalid, 0x55555555 = valid.
key	The corresponding public ECC key. See cy_stc_cryptolite_ecc_key.

Returns

status code. See cy_en_cryptolite_status_t.

Function Usage

    cy_en_cryptolite_status_t status = CY_CRYPTOLITE_BAD_PARAMS;
    cy_stc_cryptolite_context_ecdsa_t sig_ctx;
    cy_stc_cryptolite_ecc_key key;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_stc_cryptolite_ecc_buffer_t ecdsa_buf;

    uint8_t ecc_p256_signature[] = {
    0x0f, 0x8c, 0x19, 0xf5, 0xaf, 0xfe, 0xa6, 0xd5, 0x93, 0xa3, 0x3e, 0x17, 0x6a, 0xa5, 0x27, 0x17,
    0xbf, 0xf8, 0xd5, 0x87, 0x51, 0x65, 0xfc, 0x63, 0xe8, 0x0a, 0x2d, 0x65, 0x58, 0x0d, 0x29, 0x57,
    0x89, 0xdb, 0x5f, 0xfb, 0x53, 0x97, 0xba, 0x4c, 0x67, 0x83, 0x4e, 0x27, 0x31, 0xee, 0x26, 0x8e,
    0xa6, 0xf7, 0xe8, 0x38, 0x46, 0xfb, 0xb0, 0x21, 0x45, 0xb3, 0x54, 0x42, 0xdb, 0x18, 0xcf, 0x0b };

    uint8_t hash_256[] =  {
    0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea, 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
    0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c, 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad };

    uint8_t ecc_p256_public_key[] = {
    0xde, 0xa5, 0xe4, 0x5d, 0x0e, 0xa3, 0x7f, 0xc5, 0x66, 0x23, 0x2a, 0x50, 0x8f, 0x4a, 0xd2, 0x0e,
    0xa1, 0x3d, 0x47, 0xe4, 0xbf, 0x5f, 0xa4, 0xd5, 0x4a, 0x57, 0xa0, 0xba, 0x01, 0x20, 0x42, 0x08,
    0x70, 0x97, 0x49, 0x6e, 0xfc, 0x58, 0x3f, 0xed, 0x8b, 0x24, 0xa5, 0xb9, 0xbe, 0x9a, 0x51, 0xde,
    0x06, 0x3f, 0x5a, 0x00, 0xa8, 0xb6, 0x98, 0xa1, 0x6f, 0xd7, 0xf2, 0x9b, 0x54, 0x85, 0xf3, 0x20};

    memset(&key, 0, sizeof(key));
    memset(&sig_ctx, 0, sizeof(sig_ctx));

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    key.type = PK_PUBLIC;
    key.curveID = CY_CRYPTOLITE_ECC_ECP_SECP256R1;
    key.pubkey.x = (void *)ecc_p256_public_key;
    key.pubkey.y = (void *)(ecc_p256_public_key +  sizeof(ecc_p256_public_key)/2);

    Cy_Cryptolite_InvertEndianness(key.pubkey.x, sizeof(ecc_p256_public_key)/2);
    Cy_Cryptolite_InvertEndianness(key.pubkey.y, sizeof(ecc_p256_public_key)/2);

    Cy_Cryptolite_InvertEndianness(hash_256, sizeof(hash_256));

    Cy_Cryptolite_InvertEndianness(ecc_p256_signature, sizeof(ecc_p256_signature)/2);
    Cy_Cryptolite_InvertEndianness(ecc_p256_signature + sizeof(ecc_p256_signature)/2, sizeof(ecc_p256_signature)/2);

    status = Cy_Cryptolite_ECC_Init(CRYPTOLITE,&sig_ctx, &ecdsa_buf);

    /* ... check for errors... */

    status = Cy_Cryptolite_ECC_VerifyHash(CRYPTOLITE, &sig_ctx, ecc_p256_signature, sizeof(ecc_p256_signature), hash_256, sizeof(hash_256), &verResult, &key);

    /* ... check for errors... */

    status =  Cy_Cryptolite_ECC_Free(CRYPTOLITE, &sig_ctx);

    /* ... check for errors & verResult to be CY_CRYPTOLITE_SIG_VALID... */

Cy_Cryptolite_ECC_SharedSecret()

cy_en_cryptolite_status_t Cy_Cryptolite_ECC_SharedSecret	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		cy_en_cryptolite_ecc_curve_id_t	curveID,
		const uint8_t *	privateKey,
		const cy_stc_cryptolite_ecc_key *	key,
		uint8_t const *	sharedSecret
	)

Generate a Shared Secret key from one private key and others public key.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
curveID	The ECC curve id.
privateKey	The pointer to the ECC private key.
key	The generated public ECC key. See cy_stc_cryptolite_ecc_key.
sharedSecret	The pointer to store the generated shared Secret.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_ED25519_Init()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_Init	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		cy_stc_cryptolite_ecc_buffer_t *	eccBuffer,
		cy_stc_cryptolite_ed25519_sha512_t *	shaFunctions
	)

Init ED25519 Context.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
eccBuffer	The pointer to the cy_stc_cryptolite_ecc_buffer_t.
shaFunctions	The pointer to the cy_stc_cryptolite_ed25519_sha512_t.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_ED25519_Free()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_Free	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext
	)

Free ED25519 Context.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_ED25519_Sign()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_Sign	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	hash,
		uint32_t	hashlen,
		uint8_t *	sig,
		const cy_stc_cryptolite_ecc_key *	key,
		cy_en_cryptolite_eddsa_sig_type_t	sigType,
		const uint8_t *	sigctx,
		uint32_t	sigctx_len
	)

Sign a message.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
hash	The message to sign. Provided as is in data buffer. This is usually the hash of the original data to be signed.
hashlen	The length of the message in bytes.
sig	[out] The destination for the signature, 'r' followed by 's'.
key	Key (Little Endian) used for signature generation. See cy_stc_cryptolite_ecc_key.
sigType	signature Type. CY_CRYPTOLITE_EDDSA_PURE,CY_CRYPTOLITE_EDDSA_CTX or CY_CRYPTOLITE_EDDSA_PREHASH
sigctx	signature context. can be NULL if EDDSA_PURE is used or if no context is provided.
sigctx_len	The length of the signature context

Returns

status code. See cy_en_cryptolite_status_t.

Function Usage

    cy_en_cryptolite_status_t crypto_status;
    cy_stc_cryptolite_context_ecdsa_t cfContext;
    cy_stc_cryptolite_ecc_buffer_t eccBuffer;
    cy_stc_cryptolite_ed25519_sha512_t shaFunctions;

    mbedtls_sha512_context g_512ctx;

    /* message and Key are treated big-endian and sig generated as little-endian
      sig(R,S) = ed25519_sign(key,msg)
    */
    CY_ALIGN(4) cy_stc_cryptolite_ecc_key myKey;
    CY_ALIGN(4) uint8_t sign_msg[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE*2] = {0};
    CY_ALIGN(4) uint8_t msg[] = {0x05,0x04,0x03,0x02,0x01};

    /* */
    CY_ALIGN(4) uint8_t prvKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE] =
    {
        0x9d, 0x61, 0xb1, 0x9d, 0xef, 0xfd, 0x5a, 0x60, 0xba, 0x84,
        0x4a, 0xf4, 0x92, 0xec, 0x2c, 0xc4, 0x44, 0x49, 0xc5, 0x69,
        0x7b, 0x32, 0x69, 0x19, 0x70, 0x3b, 0xac, 0x03, 0x1c, 0xae,
        0x7f, 0x60
    };

    CY_ALIGN(4) uint8_t pubKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE*2] = {0};

    myKey.curveID = CY_CRYPTOLITE_ECC_ECP_ED25519;
    myKey.type = PK_PRIVATE;
    myKey.k = prvKey;
    myKey.pubkey.x = &pubKey[0];
    myKey.pubkey.y = &pubKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE];

    uint8_t *msg_ptr = msg;
    uint32_t msg_size = sizeof(msg);

    static const uint8_t publicKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE] =
    {
        0xD7,0x5A,0x98,0x01,0x82,0xB1,0x0A,0xB7,0xD5,0x4B,0xFE,0xD3,
        0xC9, 0x64, 0x07, 0x3A, 0x0E, 0xE1, 0x72, 0xF3, 0xDA, 0xA6,
        0x23, 0x25, 0xAF, 0x02, 0x1A, 0x68, 0xF7, 0x07, 0x51, 0x1A
    };


    /* Initialize user defined sha512 function pointers */
    shaFunctions.shactx = &g_512ctx;
    shaFunctions.sha_init = hook_sha512_init;
    shaFunctions.sha_start = hook_sha512_start;
    shaFunctions.sha_update = hook_sha512_update;
    shaFunctions.sha_finish = hook_sha512_finish;
    shaFunctions.sha_free = hook_sha512_free;

    Cy_Cryptolite_ED25519_Init(CRYPTOLITE, &cfContext, &eccBuffer, &shaFunctions);

    /* public key decode test*/
    crypto_status = Cy_Cryptolite_ED25519_PointDecode(CRYPTOLITE, &cfContext, publicKey, myKey.pubkey.x, myKey.pubkey.y);

    /* Generate Pub Key Test*/
    /* private key expected in big-endian */
    crypto_status = Cy_Cryptolite_ED25519_MakePublicKey(CRYPTOLITE, &cfContext, prvKey, &myKey);

    /* ... check for errors... */

    /* CY_CRYPTOLITE_EDDSA_PURE*/
    /* Public Key should be in little Endian */
    crypto_status = Cy_Cryptolite_ED25519_Sign(CRYPTOLITE, &cfContext, msg_ptr, msg_size, sign_msg, &myKey, CY_CRYPTOLITE_EDDSA_PURE, NULL, 0);
    /* ... check for errors... */

    /* Verify signatures */
    uint32_t stat = 0;
    /* PURE Verify*/
    msg_ptr = msg;
    msg_size = sizeof(msg);

    crypto_status = Cy_Cryptolite_ED25519_Verify(CRYPTOLITE, &cfContext, sign_msg, msg_ptr, msg_size, &myKey, &stat, CY_CRYPTOLITE_EDDSA_PURE, NULL, 0);

    /* ... check for errors... */

Cy_Cryptolite_ED25519_PointMultiplication()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_PointMultiplication	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	ecpGX,
		const uint8_t *	ecpGY,
		const uint8_t *	ecpD,
		uint8_t *	ecpQX,
		uint8_t *	ecpQY
	)

Edwards 25519 elliptic curve point multiplication in GF(p).

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
ecpGX	X coordinate of base point.
ecpGY	Y coordinate of base point.
ecpD	multiplication scalar value.
ecpQX	X coordinate of result point.
ecpQY	Y coordinate of result point.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_ED25519_PointDecode()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_PointDecode	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	publicKey,
		uint8_t *	pubKey_x,
		uint8_t *	pubKey_y
	)

Decode ED25519 encoded public key in to x and y.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
publicKey	[in] encoded 32 byte Public key.
pubKey_x	[out] Decoded 32 bytes Public key x in little-endian format.
pubKey_y	[out] Decoded 32 bytes Public key y in little-endian format.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_ED25519_Verify()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_Verify	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		uint8_t *	sig,
		const uint8_t *	hash,
		uint32_t	hashlen,
		const cy_stc_cryptolite_ecc_key *	key,
		uint32_t *	stat,
		cy_en_cryptolite_eddsa_sig_type_t	sigType,
		const uint8_t *	sigctx,
		uint32_t	sigctx_len
	)

Verify ED25519 signed message.

On successful verification, CY_CRYPTOLITE_SUCCESS is returned and stat is 0xA1A1A1A1.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
sig	The signature to verify, 'R' followed by 'S'.
hash	The hash or message that was signed.
hashlen	The length of the hash or message (octets).
stat	Result of signature verification, 0xA1A1A1A1==valid, 0x00BADBAD==invalid.
key	The corresponding uncompressed public key to use (little-endian). See cy_stc_cryptolite_ecc_key.
sigType	signature Type. CY_CRYPTOLITE_EDDSA_PURE,CY_CRYPTOLITE_EDDSA_CTX or CY_CRYPTOLITE_EDDSA_PREHASH
sigctx	signature context. can be NULL if EDDSA_PURE is used or if no context is provided.
sigctx_len	The length of the signature context

Returns

status code. See cy_en_cryptolite_status_t.

Function Usage

    cy_en_cryptolite_status_t crypto_status;
    cy_stc_cryptolite_context_ecdsa_t cfContext;
    cy_stc_cryptolite_ecc_buffer_t eccBuffer;
    cy_stc_cryptolite_ed25519_sha512_t shaFunctions;

    mbedtls_sha512_context g_512ctx;

    /* message and Key are treated big-endian and sig generated as little-endian
      sig(R,S) = ed25519_sign(key,msg)
    */
    CY_ALIGN(4) cy_stc_cryptolite_ecc_key myKey;
    CY_ALIGN(4) uint8_t sign_msg[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE*2] = {0};
    CY_ALIGN(4) uint8_t msg[] = {0x05,0x04,0x03,0x02,0x01};

    /* */
    CY_ALIGN(4) uint8_t prvKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE] =
    {
        0x9d, 0x61, 0xb1, 0x9d, 0xef, 0xfd, 0x5a, 0x60, 0xba, 0x84,
        0x4a, 0xf4, 0x92, 0xec, 0x2c, 0xc4, 0x44, 0x49, 0xc5, 0x69,
        0x7b, 0x32, 0x69, 0x19, 0x70, 0x3b, 0xac, 0x03, 0x1c, 0xae,
        0x7f, 0x60
    };

    CY_ALIGN(4) uint8_t pubKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE*2] = {0};

    myKey.curveID = CY_CRYPTOLITE_ECC_ECP_ED25519;
    myKey.type = PK_PRIVATE;
    myKey.k = prvKey;
    myKey.pubkey.x = &pubKey[0];
    myKey.pubkey.y = &pubKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE];

    uint8_t *msg_ptr = msg;
    uint32_t msg_size = sizeof(msg);

    static const uint8_t publicKey[CY_CRYPTOLITE_ECC_ED25519_BYTE_SIZE] =
    {
        0xD7,0x5A,0x98,0x01,0x82,0xB1,0x0A,0xB7,0xD5,0x4B,0xFE,0xD3,
        0xC9, 0x64, 0x07, 0x3A, 0x0E, 0xE1, 0x72, 0xF3, 0xDA, 0xA6,
        0x23, 0x25, 0xAF, 0x02, 0x1A, 0x68, 0xF7, 0x07, 0x51, 0x1A
    };


    /* Initialize user defined sha512 function pointers */
    shaFunctions.shactx = &g_512ctx;
    shaFunctions.sha_init = hook_sha512_init;
    shaFunctions.sha_start = hook_sha512_start;
    shaFunctions.sha_update = hook_sha512_update;
    shaFunctions.sha_finish = hook_sha512_finish;
    shaFunctions.sha_free = hook_sha512_free;

    Cy_Cryptolite_ED25519_Init(CRYPTOLITE, &cfContext, &eccBuffer, &shaFunctions);

    /* public key decode test*/
    crypto_status = Cy_Cryptolite_ED25519_PointDecode(CRYPTOLITE, &cfContext, publicKey, myKey.pubkey.x, myKey.pubkey.y);

    /* Generate Pub Key Test*/
    /* private key expected in big-endian */
    crypto_status = Cy_Cryptolite_ED25519_MakePublicKey(CRYPTOLITE, &cfContext, prvKey, &myKey);

    /* ... check for errors... */

    /* CY_CRYPTOLITE_EDDSA_PURE*/
    /* Public Key should be in little Endian */
    crypto_status = Cy_Cryptolite_ED25519_Sign(CRYPTOLITE, &cfContext, msg_ptr, msg_size, sign_msg, &myKey, CY_CRYPTOLITE_EDDSA_PURE, NULL, 0);
    /* ... check for errors... */

    /* Verify signatures */
    uint32_t stat = 0;
    /* PURE Verify*/
    msg_ptr = msg;
    msg_size = sizeof(msg);

    crypto_status = Cy_Cryptolite_ED25519_Verify(CRYPTOLITE, &cfContext, sign_msg, msg_ptr, msg_size, &myKey, &stat, CY_CRYPTOLITE_EDDSA_PURE, NULL, 0);

    /* ... check for errors... */

Cy_Cryptolite_ED25519_MakePublicKey()

cy_en_cryptolite_status_t Cy_Cryptolite_ED25519_MakePublicKey	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	privateKey,
		cy_stc_cryptolite_ecc_key *	publicKey
	)

Make a new ED25519 public key.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
privateKey	[in] Private key.
publicKey	[out] Newly created Public key. See cy_stc_cryptolite_ecc_key.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_EC25519_MakePublicKey()

cy_en_cryptolite_status_t Cy_Cryptolite_EC25519_MakePublicKey	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		const uint8_t *	privateKey,
		cy_stc_cryptolite_ecc_key *	publicKey
	)

Make a new EC25519 public key.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
privateKey	[in] Private key.
publicKey	[out] Newly created Public key. See cy_stc_cryptolite_ecc_key.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_EC25519_MakePrivateKey()

cy_en_cryptolite_status_t Cy_Cryptolite_EC25519_MakePrivateKey	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		uint8_t *	privateKey,
		cy_func_get_random_data_t	GetRandomDataFunc,
		void *	randomDataInfo
	)

Make a new EC25519 private key.

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
privateKey	[out] Destination of the newly created key.
GetRandomDataFunc	See cy_func_get_random_data_t.
randomDataInfo	Argument for GetRandomDataFunc.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_EC25519_PointMultiplication()

cy_en_cryptolite_status_t Cy_Cryptolite_EC25519_PointMultiplication	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_ecdsa_t *	cfContext,
		uint8_t *	p_r,
		const uint8_t *	p_x,
		const uint8_t *	p_d
	)

EC25519 Elliptic curve point multiplication in GF(p).

Parameters

base	The pointer to a Cryptolite instance.
cfContext	The pointer to the cy_stc_cryptolite_context_ecdsa_t.
p_r	Pointer to result point.
p_x	Pointer to X coordinate of base point.
p_d	Pointer to Scalar multiplication value.

Returns

status code. See cy_en_cryptolite_status_t.

Cy_Cryptolite_Rsa_Init()

cy_en_cryptolite_status_t Cy_Cryptolite_Rsa_Init	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_rsa_t *	cfContext,
		cy_stc_cryptolite_rsa_buffer_t *	rsaBuffers
	)

Initialize the RSA context.

Parameters

base	The pointer to the CRYPTOLITE instance.
cfContext	The pointer to the CRYPTOLITE context.
rsaBuffers	The pointer to the RSA buffers.

Returns

cy_en_cryptolite_status_t

Function Usage

    CY_ALIGN(4) uint8_t encryptedSignature_2048[] =
    {
        0x86, 0x1c, 0xf4, 0x97, 0xcc, 0xb0, 0xf9, 0x8e, 0xb1, 0x93, 0x20, 0x30, 0x5b, 0xe4, 0xe2, 0xf4,
        0x30, 0x66, 0xa3, 0x6d, 0xe8, 0x74, 0x4f, 0xa9, 0xe9, 0xd1, 0x16, 0xc5, 0x17, 0xc0, 0x97, 0x1d,
        0x60, 0x39, 0xb0, 0xda, 0xf4, 0x65, 0xad, 0x7e, 0x59, 0x6c, 0xce, 0x12, 0x29, 0x8b, 0x23, 0xdd,
        0x4b, 0xb6, 0xd3, 0xb6, 0x7e, 0x2b, 0x5d, 0xae, 0x55, 0x5e, 0x43, 0xf3, 0x61, 0x8a, 0x8c, 0xbd,
        0x47, 0x59, 0x05, 0x21, 0x4b, 0x54, 0x7b, 0x49, 0xd2, 0xbd, 0x33, 0xdb, 0x82, 0x5d, 0xfc, 0xb4,
        0xf8, 0xcf, 0x37, 0x2d, 0x2f, 0x04, 0x76, 0x66, 0x0d, 0x16, 0xea, 0x28, 0xb3, 0xde, 0x40, 0x86,
        0x8d, 0x83, 0x2d, 0xca, 0x6d, 0x5d, 0xac, 0xf5, 0x0e, 0x4f, 0xb3, 0xb3, 0x04, 0xb6, 0x91, 0x87,
        0xab, 0xac, 0x1f, 0x2f, 0xdc, 0x50, 0xf5, 0x9d, 0x88, 0xe3, 0x20, 0x23, 0xcc, 0xb0, 0x8a, 0x1f,
        0xf9, 0x7e, 0x08, 0xb0, 0x55, 0x3f, 0xf5, 0xa4, 0x86, 0x25, 0x77, 0x62, 0x7e, 0x51, 0x55, 0xe8,
        0x1f, 0xd5, 0x24, 0xf5, 0xa8, 0x5a, 0x97, 0xb6, 0x0a, 0x8e, 0xe3, 0x65, 0x6d, 0xfd, 0xe3, 0xc6,
        0xff, 0x1b, 0x32, 0x0d, 0xdb, 0x99, 0x55, 0x7b, 0x06, 0xd0, 0x98, 0xea, 0xae, 0xa9, 0xbc, 0xcd,
        0xa1, 0x81, 0xad, 0x07, 0xc7, 0xd8, 0x4a, 0xa9, 0x6e, 0x3f, 0xc6, 0xdf, 0x7c, 0x12, 0xce, 0xb3,
        0x8e, 0x5d, 0x30, 0x2b, 0xb8, 0x66, 0xf4, 0xf9, 0xc8, 0xa0, 0xcc, 0x83, 0x70, 0x46, 0x31, 0x3a,
        0x98, 0x29, 0xae, 0x60, 0x38, 0x6f, 0xe2, 0x7e, 0xac, 0x5b, 0x8e, 0x15, 0xa0, 0x21, 0x00, 0x78,
        0x72, 0x4c, 0x87, 0x70, 0x60, 0x6a, 0x23, 0x9a, 0x49, 0x7f, 0x93, 0xfd, 0x26, 0x3f, 0xb9, 0x3d,
        0x3e, 0xa8, 0xfe, 0x0a, 0x0c, 0xc6, 0x67, 0x37, 0x19, 0x03, 0xdf, 0xe5, 0x4f, 0x6d, 0x03, 0x4d,
    };


    CY_ALIGN(4) uint8_t modulus_2048[] =
    {

    /* Big endian format */
        0xbf,0xbe,0x6e,0xc4,0x9e,0x76,0x9d,0x45,0xf9,0x17,0x32,0x9d,0x4a,0xa0,0xe4,0xf0,
        0xf9,0x9f,0x02,0x6b,0xb2,0xcb,0x8a,0xe0,0x51,0xd4,0xea,0x7c,0x7c,0xdf,0xa2,0xa9,
        0xa5,0x5a,0x64,0x42,0x76,0xcd,0x38,0x90,0x3d,0x42,0x91,0x3d,0x1b,0xc6,0x6c,0x80,
        0xc6,0xd7,0x16,0xcb,0x93,0xfe,0x59,0x1f,0xa7,0x97,0x1f,0x57,0xd5,0x6b,0x33,0x53,
        0xc8,0x54,0x7f,0xa6,0x4e,0xf8,0x26,0x7e,0x6e,0xd5,0x1f,0x78,0x31,0x32,0xdf,0xca,
        0x82,0x39,0xb1,0x42,0x57,0xa8,0xa8,0x9f,0x93,0x4e,0x39,0x7b,0xa7,0xf0,0x39,0x61,
        0x42,0x31,0x38,0xa2,0xff,0x05,0xf5,0x0d,0x06,0x0d,0x26,0x66,0xe5,0x71,0x6f,0x0d,
        0x52,0x24,0x6f,0x4d,0x83,0x8e,0x97,0xda,0x88,0x91,0x41,0xe4,0x16,0x31,0x70,0x69,
        0xea,0x3a,0x61,0x4f,0xb3,0x58,0x4c,0xc7,0xdd,0xf0,0x6a,0xd0,0x7b,0xa5,0x2c,0x47,
        0x03,0x06,0x7a,0x31,0x8f,0xab,0xc7,0xca,0x73,0xc4,0xa9,0xe8,0x17,0xd3,0xff,0x2e,
        0x2b,0x0d,0x60,0x48,0x5d,0x69,0x8a,0xa0,0xb4,0x8e,0x37,0xe9,0xf5,0x2d,0xb7,0x5f,
        0xfd,0x27,0x2b,0x65,0x05,0xfc,0xab,0x43,0x43,0xdc,0x84,0x40,0x7f,0x1b,0x67,0x7d,
        0x7e,0xc1,0xa7,0xf5,0x37,0xfa,0xb9,0xcd,0x56,0x7f,0xde,0xb3,0xb8,0x76,0x90,0xf4,
        0x00,0x3b,0xcc,0x9b,0xb6,0xf8,0xec,0xbc,0x41,0x92,0x71,0xe3,0xe2,0xf3,0x0d,0xf9,
        0xd7,0x7a,0x2a,0x27,0x3f,0x80,0xb3,0x98,0x9d,0x39,0xaa,0x10,0xdc,0x8b,0x6c,0x16,
        0xca,0x97,0xef,0x55,0xd6,0x5f,0x18,0x89,0x61,0x0e,0x24,0xb9,0x11,0x4d,0x6e,0xc7
    };

    CY_ALIGN(4)  uint8_t plainTxt[] = "abc";

    CY_ALIGN(4) uint8_t publicExponent[] =
    {
    /* This is a part of public key. (So called e)
    * Refer public_key.txt
    */
    /* Big endian format */
        0x01, 0x00, 0x01
    };

    CY_ALIGN(4) uint8_t barretCoef[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};  /* Must be modulo length + 1 BITS */
    CY_ALIGN(4) uint8_t inverseModulo[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};    /* Must be same as modulo length */
    CY_ALIGN(4) uint8_t rBar[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};             /* Must be same as modulo length */


    CY_ALIGN(4)uint8_t decryptedSignature[2048/8]={0};
    CY_ALIGN(4) uint8_t calculatedHash[32]={0};
    cy_stc_cryptolite_rsa_buffer_t rsa_buffer;

    cy_stc_cryptolite_context_rsa_t rsa_ctx;
    cy_stc_cryptolite_context_sha256_t sha_ctx;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_en_cryptolite_status_t status;

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    memset((void*)&decryptedSignature, 0u, sizeof(decryptedSignature));
    memset((void*)&calculatedHash, 0u, sizeof(calculatedHash));
    memset((void*)&rsa_buffer, 0u, sizeof(rsa_buffer));
    memset((void*)&rsa_ctx, 0u, sizeof(rsa_ctx));
    memset((void*)&sha_ctx, 0u, sizeof(sha_ctx));

    Cy_Cryptolite_InvertEndianness(modulus_2048, 2048u/8 );
    Cy_Cryptolite_InvertEndianness(encryptedSignature_2048, sizeof(encryptedSignature_2048) );

    Cy_Cryptolite_InvertEndianness(publicExponent, sizeof(publicExponent));

    cy_stc_cryptolite_rsa_pub_key_t pubKeyPtr =
    {
        .moduloPtr          = modulus_2048,
        .moduloLength       = 2048u,
        .pubExpPtr          = publicExponent,
        .pubExpLength       = sizeof(publicExponent)* 8,       /* 17 bits */
        .barretCoefPtr       = barretCoef,
        .inverseModuloPtr    = inverseModulo,
        .rBarPtr             = rBar,
        .preCalculatedCoeff  = false
    };

    status = Cy_Cryptolite_Rsa_Init(CRYPTOLITE, &rsa_ctx, &rsa_buffer);

    /* ... check for errors... */

    /* At first decrypt the received signature. */
    status = Cy_Cryptolite_Rsa_Proc(CRYPTOLITE, &rsa_ctx, &pubKeyPtr, encryptedSignature_2048, 2048u, decryptedSignature);

    /* ... check for errors... */

    /* Calculate the hash from the plain text */
    status = Cy_Cryptolite_Sha256_Run(CRYPTOLITE, plainTxt, sizeof(plainTxt)-1, calculatedHash, &sha_ctx);

    /* ... check for errors... */

    Cy_Cryptolite_InvertEndianness(decryptedSignature, sizeof(encryptedSignature_2048));

    /* Finally verify decrypted signature with calculated digest */
    status = Cy_Cryptolite_Rsa_Verify(CRYPTOLITE, &rsa_ctx, &verResult, CY_CRYPTOLITE_MODE_SHA256, calculatedHash, sizeof(calculatedHash), decryptedSignature, sizeof(encryptedSignature_2048));

    /* ... check for errors... */

    Cy_Cryptolite_Rsa_Free(CRYPTOLITE, &rsa_ctx);

    /* ... check verResult is CY_CRYPTOLITE_SIG_VALID... */

Cy_Cryptolite_Rsa_Proc()

cy_en_cryptolite_status_t Cy_Cryptolite_Rsa_Proc	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_rsa_t *	cfContext,
		cy_stc_cryptolite_rsa_pub_key_t *	key,
		uint8_t const *	message,
		uint32_t	messageSize,
		uint8_t *	processedMessage
	)

RSA process algorithm based on the Montgomery algorithm using Barrett reduction.

https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29

Key, message, processedMessage buffers must be 4 byte aligned and end with 4 byte boundary.

Parameters

base	The pointer to the CRYPTOLITE instance.
cfContext	The pointer to the CRYPTOLITE context.
key	The pointer to the cy_stc_cryptolite_rsa_pub_key_t structure that stores public key.
message	The pointer to the message to be processed.
messageSize	The length of the message to be processed.
processedMessage	The pointer to processed message.

Returns

cy_en_cryptolite_status_t

Function Usage

    CY_ALIGN(4) uint8_t encryptedSignature_2048[] =
    {
        0x86, 0x1c, 0xf4, 0x97, 0xcc, 0xb0, 0xf9, 0x8e, 0xb1, 0x93, 0x20, 0x30, 0x5b, 0xe4, 0xe2, 0xf4,
        0x30, 0x66, 0xa3, 0x6d, 0xe8, 0x74, 0x4f, 0xa9, 0xe9, 0xd1, 0x16, 0xc5, 0x17, 0xc0, 0x97, 0x1d,
        0x60, 0x39, 0xb0, 0xda, 0xf4, 0x65, 0xad, 0x7e, 0x59, 0x6c, 0xce, 0x12, 0x29, 0x8b, 0x23, 0xdd,
        0x4b, 0xb6, 0xd3, 0xb6, 0x7e, 0x2b, 0x5d, 0xae, 0x55, 0x5e, 0x43, 0xf3, 0x61, 0x8a, 0x8c, 0xbd,
        0x47, 0x59, 0x05, 0x21, 0x4b, 0x54, 0x7b, 0x49, 0xd2, 0xbd, 0x33, 0xdb, 0x82, 0x5d, 0xfc, 0xb4,
        0xf8, 0xcf, 0x37, 0x2d, 0x2f, 0x04, 0x76, 0x66, 0x0d, 0x16, 0xea, 0x28, 0xb3, 0xde, 0x40, 0x86,
        0x8d, 0x83, 0x2d, 0xca, 0x6d, 0x5d, 0xac, 0xf5, 0x0e, 0x4f, 0xb3, 0xb3, 0x04, 0xb6, 0x91, 0x87,
        0xab, 0xac, 0x1f, 0x2f, 0xdc, 0x50, 0xf5, 0x9d, 0x88, 0xe3, 0x20, 0x23, 0xcc, 0xb0, 0x8a, 0x1f,
        0xf9, 0x7e, 0x08, 0xb0, 0x55, 0x3f, 0xf5, 0xa4, 0x86, 0x25, 0x77, 0x62, 0x7e, 0x51, 0x55, 0xe8,
        0x1f, 0xd5, 0x24, 0xf5, 0xa8, 0x5a, 0x97, 0xb6, 0x0a, 0x8e, 0xe3, 0x65, 0x6d, 0xfd, 0xe3, 0xc6,
        0xff, 0x1b, 0x32, 0x0d, 0xdb, 0x99, 0x55, 0x7b, 0x06, 0xd0, 0x98, 0xea, 0xae, 0xa9, 0xbc, 0xcd,
        0xa1, 0x81, 0xad, 0x07, 0xc7, 0xd8, 0x4a, 0xa9, 0x6e, 0x3f, 0xc6, 0xdf, 0x7c, 0x12, 0xce, 0xb3,
        0x8e, 0x5d, 0x30, 0x2b, 0xb8, 0x66, 0xf4, 0xf9, 0xc8, 0xa0, 0xcc, 0x83, 0x70, 0x46, 0x31, 0x3a,
        0x98, 0x29, 0xae, 0x60, 0x38, 0x6f, 0xe2, 0x7e, 0xac, 0x5b, 0x8e, 0x15, 0xa0, 0x21, 0x00, 0x78,
        0x72, 0x4c, 0x87, 0x70, 0x60, 0x6a, 0x23, 0x9a, 0x49, 0x7f, 0x93, 0xfd, 0x26, 0x3f, 0xb9, 0x3d,
        0x3e, 0xa8, 0xfe, 0x0a, 0x0c, 0xc6, 0x67, 0x37, 0x19, 0x03, 0xdf, 0xe5, 0x4f, 0x6d, 0x03, 0x4d,
    };


    CY_ALIGN(4) uint8_t modulus_2048[] =
    {

    /* Big endian format */
        0xbf,0xbe,0x6e,0xc4,0x9e,0x76,0x9d,0x45,0xf9,0x17,0x32,0x9d,0x4a,0xa0,0xe4,0xf0,
        0xf9,0x9f,0x02,0x6b,0xb2,0xcb,0x8a,0xe0,0x51,0xd4,0xea,0x7c,0x7c,0xdf,0xa2,0xa9,
        0xa5,0x5a,0x64,0x42,0x76,0xcd,0x38,0x90,0x3d,0x42,0x91,0x3d,0x1b,0xc6,0x6c,0x80,
        0xc6,0xd7,0x16,0xcb,0x93,0xfe,0x59,0x1f,0xa7,0x97,0x1f,0x57,0xd5,0x6b,0x33,0x53,
        0xc8,0x54,0x7f,0xa6,0x4e,0xf8,0x26,0x7e,0x6e,0xd5,0x1f,0x78,0x31,0x32,0xdf,0xca,
        0x82,0x39,0xb1,0x42,0x57,0xa8,0xa8,0x9f,0x93,0x4e,0x39,0x7b,0xa7,0xf0,0x39,0x61,
        0x42,0x31,0x38,0xa2,0xff,0x05,0xf5,0x0d,0x06,0x0d,0x26,0x66,0xe5,0x71,0x6f,0x0d,
        0x52,0x24,0x6f,0x4d,0x83,0x8e,0x97,0xda,0x88,0x91,0x41,0xe4,0x16,0x31,0x70,0x69,
        0xea,0x3a,0x61,0x4f,0xb3,0x58,0x4c,0xc7,0xdd,0xf0,0x6a,0xd0,0x7b,0xa5,0x2c,0x47,
        0x03,0x06,0x7a,0x31,0x8f,0xab,0xc7,0xca,0x73,0xc4,0xa9,0xe8,0x17,0xd3,0xff,0x2e,
        0x2b,0x0d,0x60,0x48,0x5d,0x69,0x8a,0xa0,0xb4,0x8e,0x37,0xe9,0xf5,0x2d,0xb7,0x5f,
        0xfd,0x27,0x2b,0x65,0x05,0xfc,0xab,0x43,0x43,0xdc,0x84,0x40,0x7f,0x1b,0x67,0x7d,
        0x7e,0xc1,0xa7,0xf5,0x37,0xfa,0xb9,0xcd,0x56,0x7f,0xde,0xb3,0xb8,0x76,0x90,0xf4,
        0x00,0x3b,0xcc,0x9b,0xb6,0xf8,0xec,0xbc,0x41,0x92,0x71,0xe3,0xe2,0xf3,0x0d,0xf9,
        0xd7,0x7a,0x2a,0x27,0x3f,0x80,0xb3,0x98,0x9d,0x39,0xaa,0x10,0xdc,0x8b,0x6c,0x16,
        0xca,0x97,0xef,0x55,0xd6,0x5f,0x18,0x89,0x61,0x0e,0x24,0xb9,0x11,0x4d,0x6e,0xc7
    };

    CY_ALIGN(4)  uint8_t plainTxt[] = "abc";

    CY_ALIGN(4) uint8_t publicExponent[] =
    {
    /* This is a part of public key. (So called e)
    * Refer public_key.txt
    */
    /* Big endian format */
        0x01, 0x00, 0x01
    };

    CY_ALIGN(4) uint8_t barretCoef[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};  /* Must be modulo length + 1 BITS */
    CY_ALIGN(4) uint8_t inverseModulo[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};    /* Must be same as modulo length */
    CY_ALIGN(4) uint8_t rBar[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};             /* Must be same as modulo length */


    CY_ALIGN(4)uint8_t decryptedSignature[2048/8]={0};
    CY_ALIGN(4) uint8_t calculatedHash[32]={0};
    cy_stc_cryptolite_rsa_buffer_t rsa_buffer;

    cy_stc_cryptolite_context_rsa_t rsa_ctx;
    cy_stc_cryptolite_context_sha256_t sha_ctx;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_en_cryptolite_status_t status;

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    memset((void*)&decryptedSignature, 0u, sizeof(decryptedSignature));
    memset((void*)&calculatedHash, 0u, sizeof(calculatedHash));
    memset((void*)&rsa_buffer, 0u, sizeof(rsa_buffer));
    memset((void*)&rsa_ctx, 0u, sizeof(rsa_ctx));
    memset((void*)&sha_ctx, 0u, sizeof(sha_ctx));

    Cy_Cryptolite_InvertEndianness(modulus_2048, 2048u/8 );
    Cy_Cryptolite_InvertEndianness(encryptedSignature_2048, sizeof(encryptedSignature_2048) );

    Cy_Cryptolite_InvertEndianness(publicExponent, sizeof(publicExponent));

    cy_stc_cryptolite_rsa_pub_key_t pubKeyPtr =
    {
        .moduloPtr          = modulus_2048,
        .moduloLength       = 2048u,
        .pubExpPtr          = publicExponent,
        .pubExpLength       = sizeof(publicExponent)* 8,       /* 17 bits */
        .barretCoefPtr       = barretCoef,
        .inverseModuloPtr    = inverseModulo,
        .rBarPtr             = rBar,
        .preCalculatedCoeff  = false
    };

    status = Cy_Cryptolite_Rsa_Init(CRYPTOLITE, &rsa_ctx, &rsa_buffer);

    /* ... check for errors... */

    /* At first decrypt the received signature. */
    status = Cy_Cryptolite_Rsa_Proc(CRYPTOLITE, &rsa_ctx, &pubKeyPtr, encryptedSignature_2048, 2048u, decryptedSignature);

    /* ... check for errors... */

    /* Calculate the hash from the plain text */
    status = Cy_Cryptolite_Sha256_Run(CRYPTOLITE, plainTxt, sizeof(plainTxt)-1, calculatedHash, &sha_ctx);

    /* ... check for errors... */

    Cy_Cryptolite_InvertEndianness(decryptedSignature, sizeof(encryptedSignature_2048));

    /* Finally verify decrypted signature with calculated digest */
    status = Cy_Cryptolite_Rsa_Verify(CRYPTOLITE, &rsa_ctx, &verResult, CY_CRYPTOLITE_MODE_SHA256, calculatedHash, sizeof(calculatedHash), decryptedSignature, sizeof(encryptedSignature_2048));

    /* ... check for errors... */

    Cy_Cryptolite_Rsa_Free(CRYPTOLITE, &rsa_ctx);

    /* ... check verResult is CY_CRYPTOLITE_SIG_VALID... */

Cy_Cryptolite_Rsa_Coef()

cy_en_cryptolite_status_t Cy_Cryptolite_Rsa_Coef	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_rsa_t *	cfContext,
		cy_stc_cryptolite_rsa_pub_key_t *	key
	)

Calculation constant coefficients to speed-up Montgomery algorithm.

These coefficients are: coefficient for Barrett reduction, binary inverse of the modulo, result of (2^moduloLength mod modulo)

Parameters

base	The pointer to the CRYPTOLITE instance.
cfContext	The pointer to the CRYPTOLITE context.
key	The pointer to the cy_stc_cryptolite_rsa_pub_key_t structure that stores a public key.

Returns

cy_en_cryptolite_status_t

Cy_Cryptolite_Rsa_Free()

cy_en_cryptolite_status_t Cy_Cryptolite_Rsa_Free	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_rsa_t *	cfContext
	)

Cleanup the RSA context.

Parameters

base	The pointer to the CRYPTOLITE instance.
cfContext	The pointer to the CRYPTOLITE context.

Returns

cy_en_cryptolite_status_t

Function Usage

    CY_ALIGN(4) uint8_t encryptedSignature_2048[] =
    {
        0x86, 0x1c, 0xf4, 0x97, 0xcc, 0xb0, 0xf9, 0x8e, 0xb1, 0x93, 0x20, 0x30, 0x5b, 0xe4, 0xe2, 0xf4,
        0x30, 0x66, 0xa3, 0x6d, 0xe8, 0x74, 0x4f, 0xa9, 0xe9, 0xd1, 0x16, 0xc5, 0x17, 0xc0, 0x97, 0x1d,
        0x60, 0x39, 0xb0, 0xda, 0xf4, 0x65, 0xad, 0x7e, 0x59, 0x6c, 0xce, 0x12, 0x29, 0x8b, 0x23, 0xdd,
        0x4b, 0xb6, 0xd3, 0xb6, 0x7e, 0x2b, 0x5d, 0xae, 0x55, 0x5e, 0x43, 0xf3, 0x61, 0x8a, 0x8c, 0xbd,
        0x47, 0x59, 0x05, 0x21, 0x4b, 0x54, 0x7b, 0x49, 0xd2, 0xbd, 0x33, 0xdb, 0x82, 0x5d, 0xfc, 0xb4,
        0xf8, 0xcf, 0x37, 0x2d, 0x2f, 0x04, 0x76, 0x66, 0x0d, 0x16, 0xea, 0x28, 0xb3, 0xde, 0x40, 0x86,
        0x8d, 0x83, 0x2d, 0xca, 0x6d, 0x5d, 0xac, 0xf5, 0x0e, 0x4f, 0xb3, 0xb3, 0x04, 0xb6, 0x91, 0x87,
        0xab, 0xac, 0x1f, 0x2f, 0xdc, 0x50, 0xf5, 0x9d, 0x88, 0xe3, 0x20, 0x23, 0xcc, 0xb0, 0x8a, 0x1f,
        0xf9, 0x7e, 0x08, 0xb0, 0x55, 0x3f, 0xf5, 0xa4, 0x86, 0x25, 0x77, 0x62, 0x7e, 0x51, 0x55, 0xe8,
        0x1f, 0xd5, 0x24, 0xf5, 0xa8, 0x5a, 0x97, 0xb6, 0x0a, 0x8e, 0xe3, 0x65, 0x6d, 0xfd, 0xe3, 0xc6,
        0xff, 0x1b, 0x32, 0x0d, 0xdb, 0x99, 0x55, 0x7b, 0x06, 0xd0, 0x98, 0xea, 0xae, 0xa9, 0xbc, 0xcd,
        0xa1, 0x81, 0xad, 0x07, 0xc7, 0xd8, 0x4a, 0xa9, 0x6e, 0x3f, 0xc6, 0xdf, 0x7c, 0x12, 0xce, 0xb3,
        0x8e, 0x5d, 0x30, 0x2b, 0xb8, 0x66, 0xf4, 0xf9, 0xc8, 0xa0, 0xcc, 0x83, 0x70, 0x46, 0x31, 0x3a,
        0x98, 0x29, 0xae, 0x60, 0x38, 0x6f, 0xe2, 0x7e, 0xac, 0x5b, 0x8e, 0x15, 0xa0, 0x21, 0x00, 0x78,
        0x72, 0x4c, 0x87, 0x70, 0x60, 0x6a, 0x23, 0x9a, 0x49, 0x7f, 0x93, 0xfd, 0x26, 0x3f, 0xb9, 0x3d,
        0x3e, 0xa8, 0xfe, 0x0a, 0x0c, 0xc6, 0x67, 0x37, 0x19, 0x03, 0xdf, 0xe5, 0x4f, 0x6d, 0x03, 0x4d,
    };


    CY_ALIGN(4) uint8_t modulus_2048[] =
    {

    /* Big endian format */
        0xbf,0xbe,0x6e,0xc4,0x9e,0x76,0x9d,0x45,0xf9,0x17,0x32,0x9d,0x4a,0xa0,0xe4,0xf0,
        0xf9,0x9f,0x02,0x6b,0xb2,0xcb,0x8a,0xe0,0x51,0xd4,0xea,0x7c,0x7c,0xdf,0xa2,0xa9,
        0xa5,0x5a,0x64,0x42,0x76,0xcd,0x38,0x90,0x3d,0x42,0x91,0x3d,0x1b,0xc6,0x6c,0x80,
        0xc6,0xd7,0x16,0xcb,0x93,0xfe,0x59,0x1f,0xa7,0x97,0x1f,0x57,0xd5,0x6b,0x33,0x53,
        0xc8,0x54,0x7f,0xa6,0x4e,0xf8,0x26,0x7e,0x6e,0xd5,0x1f,0x78,0x31,0x32,0xdf,0xca,
        0x82,0x39,0xb1,0x42,0x57,0xa8,0xa8,0x9f,0x93,0x4e,0x39,0x7b,0xa7,0xf0,0x39,0x61,
        0x42,0x31,0x38,0xa2,0xff,0x05,0xf5,0x0d,0x06,0x0d,0x26,0x66,0xe5,0x71,0x6f,0x0d,
        0x52,0x24,0x6f,0x4d,0x83,0x8e,0x97,0xda,0x88,0x91,0x41,0xe4,0x16,0x31,0x70,0x69,
        0xea,0x3a,0x61,0x4f,0xb3,0x58,0x4c,0xc7,0xdd,0xf0,0x6a,0xd0,0x7b,0xa5,0x2c,0x47,
        0x03,0x06,0x7a,0x31,0x8f,0xab,0xc7,0xca,0x73,0xc4,0xa9,0xe8,0x17,0xd3,0xff,0x2e,
        0x2b,0x0d,0x60,0x48,0x5d,0x69,0x8a,0xa0,0xb4,0x8e,0x37,0xe9,0xf5,0x2d,0xb7,0x5f,
        0xfd,0x27,0x2b,0x65,0x05,0xfc,0xab,0x43,0x43,0xdc,0x84,0x40,0x7f,0x1b,0x67,0x7d,
        0x7e,0xc1,0xa7,0xf5,0x37,0xfa,0xb9,0xcd,0x56,0x7f,0xde,0xb3,0xb8,0x76,0x90,0xf4,
        0x00,0x3b,0xcc,0x9b,0xb6,0xf8,0xec,0xbc,0x41,0x92,0x71,0xe3,0xe2,0xf3,0x0d,0xf9,
        0xd7,0x7a,0x2a,0x27,0x3f,0x80,0xb3,0x98,0x9d,0x39,0xaa,0x10,0xdc,0x8b,0x6c,0x16,
        0xca,0x97,0xef,0x55,0xd6,0x5f,0x18,0x89,0x61,0x0e,0x24,0xb9,0x11,0x4d,0x6e,0xc7
    };

    CY_ALIGN(4)  uint8_t plainTxt[] = "abc";

    CY_ALIGN(4) uint8_t publicExponent[] =
    {
    /* This is a part of public key. (So called e)
    * Refer public_key.txt
    */
    /* Big endian format */
        0x01, 0x00, 0x01
    };

    CY_ALIGN(4) uint8_t barretCoef[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};  /* Must be modulo length + 1 BITS */
    CY_ALIGN(4) uint8_t inverseModulo[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};    /* Must be same as modulo length */
    CY_ALIGN(4) uint8_t rBar[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};             /* Must be same as modulo length */


    CY_ALIGN(4)uint8_t decryptedSignature[2048/8]={0};
    CY_ALIGN(4) uint8_t calculatedHash[32]={0};
    cy_stc_cryptolite_rsa_buffer_t rsa_buffer;

    cy_stc_cryptolite_context_rsa_t rsa_ctx;
    cy_stc_cryptolite_context_sha256_t sha_ctx;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_en_cryptolite_status_t status;

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    memset((void*)&decryptedSignature, 0u, sizeof(decryptedSignature));
    memset((void*)&calculatedHash, 0u, sizeof(calculatedHash));
    memset((void*)&rsa_buffer, 0u, sizeof(rsa_buffer));
    memset((void*)&rsa_ctx, 0u, sizeof(rsa_ctx));
    memset((void*)&sha_ctx, 0u, sizeof(sha_ctx));

    Cy_Cryptolite_InvertEndianness(modulus_2048, 2048u/8 );
    Cy_Cryptolite_InvertEndianness(encryptedSignature_2048, sizeof(encryptedSignature_2048) );

    Cy_Cryptolite_InvertEndianness(publicExponent, sizeof(publicExponent));

    cy_stc_cryptolite_rsa_pub_key_t pubKeyPtr =
    {
        .moduloPtr          = modulus_2048,
        .moduloLength       = 2048u,
        .pubExpPtr          = publicExponent,
        .pubExpLength       = sizeof(publicExponent)* 8,       /* 17 bits */
        .barretCoefPtr       = barretCoef,
        .inverseModuloPtr    = inverseModulo,
        .rBarPtr             = rBar,
        .preCalculatedCoeff  = false
    };

    status = Cy_Cryptolite_Rsa_Init(CRYPTOLITE, &rsa_ctx, &rsa_buffer);

    /* ... check for errors... */

    /* At first decrypt the received signature. */
    status = Cy_Cryptolite_Rsa_Proc(CRYPTOLITE, &rsa_ctx, &pubKeyPtr, encryptedSignature_2048, 2048u, decryptedSignature);

    /* ... check for errors... */

    /* Calculate the hash from the plain text */
    status = Cy_Cryptolite_Sha256_Run(CRYPTOLITE, plainTxt, sizeof(plainTxt)-1, calculatedHash, &sha_ctx);

    /* ... check for errors... */

    Cy_Cryptolite_InvertEndianness(decryptedSignature, sizeof(encryptedSignature_2048));

    /* Finally verify decrypted signature with calculated digest */
    status = Cy_Cryptolite_Rsa_Verify(CRYPTOLITE, &rsa_ctx, &verResult, CY_CRYPTOLITE_MODE_SHA256, calculatedHash, sizeof(calculatedHash), decryptedSignature, sizeof(encryptedSignature_2048));

    /* ... check for errors... */

    Cy_Cryptolite_Rsa_Free(CRYPTOLITE, &rsa_ctx);

    /* ... check verResult is CY_CRYPTOLITE_SIG_VALID... */

Cy_Cryptolite_Rsa_Verify()

cy_en_cryptolite_status_t Cy_Cryptolite_Rsa_Verify	(	CRYPTOLITE_Type *	base,
		cy_stc_cryptolite_context_rsa_t *	cfContext,
		cy_en_cryptolite_sig_verify_result_t *	verResult,
		cy_en_cryptolite_sha_mode_t	digestType,
		uint8_t const *	digest,
		uint32_t	digestLength,
		uint8_t const *	decryptedSignature,
		uint32_t	decryptedSignatureLength
	)

RSA verification with checks for content, paddings and signature format.

SHA digest of the message and decrypted message should be calculated before. Supports only PKCS1-v1_5 format, inside of this format supported padding using only SHA, cases with MD2 and MD5 are not supported. PKCS1-v1_5 described here, page 31: http://www.emc.com/collateral/white-papers/h11300-pkcs-1v2-2-rsa-cryptography-standard-wp.pdf

The digest and decryptedSignature buffers must be 4 byte aligned

Returns the verification result cy_en_cryptolite_sig_verify_result_t.

Parameters

base	The pointer to the CRYPTOLITE instance.
cfContext	The pointer to the CRYPTOLITE context.
verResult	The pointer to the verification result cy_en_cryptolite_sig_verify_result_t.
digestType	SHA mode used for hash calculation cy_en_cryptolite_sha_mode_t.
digest	The pointer to the hash of the message or the message whose signature is to be verified.
digestLength	The length of the message whose signature is to be verified and is applicable for CY_CRYPTOLITE_MODE_SHA_NONE mode.
decryptedSignature	The pointer to the decrypted signature to be verified.
decryptedSignatureLength	The length of the decrypted signature to be verified (in bytes)

Returns

cy_en_cryptolite_status_t

Function Usage

    CY_ALIGN(4) uint8_t encryptedSignature_2048[] =
    {
        0x86, 0x1c, 0xf4, 0x97, 0xcc, 0xb0, 0xf9, 0x8e, 0xb1, 0x93, 0x20, 0x30, 0x5b, 0xe4, 0xe2, 0xf4,
        0x30, 0x66, 0xa3, 0x6d, 0xe8, 0x74, 0x4f, 0xa9, 0xe9, 0xd1, 0x16, 0xc5, 0x17, 0xc0, 0x97, 0x1d,
        0x60, 0x39, 0xb0, 0xda, 0xf4, 0x65, 0xad, 0x7e, 0x59, 0x6c, 0xce, 0x12, 0x29, 0x8b, 0x23, 0xdd,
        0x4b, 0xb6, 0xd3, 0xb6, 0x7e, 0x2b, 0x5d, 0xae, 0x55, 0x5e, 0x43, 0xf3, 0x61, 0x8a, 0x8c, 0xbd,
        0x47, 0x59, 0x05, 0x21, 0x4b, 0x54, 0x7b, 0x49, 0xd2, 0xbd, 0x33, 0xdb, 0x82, 0x5d, 0xfc, 0xb4,
        0xf8, 0xcf, 0x37, 0x2d, 0x2f, 0x04, 0x76, 0x66, 0x0d, 0x16, 0xea, 0x28, 0xb3, 0xde, 0x40, 0x86,
        0x8d, 0x83, 0x2d, 0xca, 0x6d, 0x5d, 0xac, 0xf5, 0x0e, 0x4f, 0xb3, 0xb3, 0x04, 0xb6, 0x91, 0x87,
        0xab, 0xac, 0x1f, 0x2f, 0xdc, 0x50, 0xf5, 0x9d, 0x88, 0xe3, 0x20, 0x23, 0xcc, 0xb0, 0x8a, 0x1f,
        0xf9, 0x7e, 0x08, 0xb0, 0x55, 0x3f, 0xf5, 0xa4, 0x86, 0x25, 0x77, 0x62, 0x7e, 0x51, 0x55, 0xe8,
        0x1f, 0xd5, 0x24, 0xf5, 0xa8, 0x5a, 0x97, 0xb6, 0x0a, 0x8e, 0xe3, 0x65, 0x6d, 0xfd, 0xe3, 0xc6,
        0xff, 0x1b, 0x32, 0x0d, 0xdb, 0x99, 0x55, 0x7b, 0x06, 0xd0, 0x98, 0xea, 0xae, 0xa9, 0xbc, 0xcd,
        0xa1, 0x81, 0xad, 0x07, 0xc7, 0xd8, 0x4a, 0xa9, 0x6e, 0x3f, 0xc6, 0xdf, 0x7c, 0x12, 0xce, 0xb3,
        0x8e, 0x5d, 0x30, 0x2b, 0xb8, 0x66, 0xf4, 0xf9, 0xc8, 0xa0, 0xcc, 0x83, 0x70, 0x46, 0x31, 0x3a,
        0x98, 0x29, 0xae, 0x60, 0x38, 0x6f, 0xe2, 0x7e, 0xac, 0x5b, 0x8e, 0x15, 0xa0, 0x21, 0x00, 0x78,
        0x72, 0x4c, 0x87, 0x70, 0x60, 0x6a, 0x23, 0x9a, 0x49, 0x7f, 0x93, 0xfd, 0x26, 0x3f, 0xb9, 0x3d,
        0x3e, 0xa8, 0xfe, 0x0a, 0x0c, 0xc6, 0x67, 0x37, 0x19, 0x03, 0xdf, 0xe5, 0x4f, 0x6d, 0x03, 0x4d,
    };


    CY_ALIGN(4) uint8_t modulus_2048[] =
    {

    /* Big endian format */
        0xbf,0xbe,0x6e,0xc4,0x9e,0x76,0x9d,0x45,0xf9,0x17,0x32,0x9d,0x4a,0xa0,0xe4,0xf0,
        0xf9,0x9f,0x02,0x6b,0xb2,0xcb,0x8a,0xe0,0x51,0xd4,0xea,0x7c,0x7c,0xdf,0xa2,0xa9,
        0xa5,0x5a,0x64,0x42,0x76,0xcd,0x38,0x90,0x3d,0x42,0x91,0x3d,0x1b,0xc6,0x6c,0x80,
        0xc6,0xd7,0x16,0xcb,0x93,0xfe,0x59,0x1f,0xa7,0x97,0x1f,0x57,0xd5,0x6b,0x33,0x53,
        0xc8,0x54,0x7f,0xa6,0x4e,0xf8,0x26,0x7e,0x6e,0xd5,0x1f,0x78,0x31,0x32,0xdf,0xca,
        0x82,0x39,0xb1,0x42,0x57,0xa8,0xa8,0x9f,0x93,0x4e,0x39,0x7b,0xa7,0xf0,0x39,0x61,
        0x42,0x31,0x38,0xa2,0xff,0x05,0xf5,0x0d,0x06,0x0d,0x26,0x66,0xe5,0x71,0x6f,0x0d,
        0x52,0x24,0x6f,0x4d,0x83,0x8e,0x97,0xda,0x88,0x91,0x41,0xe4,0x16,0x31,0x70,0x69,
        0xea,0x3a,0x61,0x4f,0xb3,0x58,0x4c,0xc7,0xdd,0xf0,0x6a,0xd0,0x7b,0xa5,0x2c,0x47,
        0x03,0x06,0x7a,0x31,0x8f,0xab,0xc7,0xca,0x73,0xc4,0xa9,0xe8,0x17,0xd3,0xff,0x2e,
        0x2b,0x0d,0x60,0x48,0x5d,0x69,0x8a,0xa0,0xb4,0x8e,0x37,0xe9,0xf5,0x2d,0xb7,0x5f,
        0xfd,0x27,0x2b,0x65,0x05,0xfc,0xab,0x43,0x43,0xdc,0x84,0x40,0x7f,0x1b,0x67,0x7d,
        0x7e,0xc1,0xa7,0xf5,0x37,0xfa,0xb9,0xcd,0x56,0x7f,0xde,0xb3,0xb8,0x76,0x90,0xf4,
        0x00,0x3b,0xcc,0x9b,0xb6,0xf8,0xec,0xbc,0x41,0x92,0x71,0xe3,0xe2,0xf3,0x0d,0xf9,
        0xd7,0x7a,0x2a,0x27,0x3f,0x80,0xb3,0x98,0x9d,0x39,0xaa,0x10,0xdc,0x8b,0x6c,0x16,
        0xca,0x97,0xef,0x55,0xd6,0x5f,0x18,0x89,0x61,0x0e,0x24,0xb9,0x11,0x4d,0x6e,0xc7
    };

    CY_ALIGN(4)  uint8_t plainTxt[] = "abc";

    CY_ALIGN(4) uint8_t publicExponent[] =
    {
    /* This is a part of public key. (So called e)
    * Refer public_key.txt
    */
    /* Big endian format */
        0x01, 0x00, 0x01
    };

    CY_ALIGN(4) uint8_t barretCoef[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};  /* Must be modulo length + 1 BITS */
    CY_ALIGN(4) uint8_t inverseModulo[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};    /* Must be same as modulo length */
    CY_ALIGN(4) uint8_t rBar[4*VU_BITS_TO_WORDS(CY_CRYPTOLITE_RSA_BITSIZE+1)]={0};             /* Must be same as modulo length */


    CY_ALIGN(4)uint8_t decryptedSignature[2048/8]={0};
    CY_ALIGN(4) uint8_t calculatedHash[32]={0};
    cy_stc_cryptolite_rsa_buffer_t rsa_buffer;

    cy_stc_cryptolite_context_rsa_t rsa_ctx;
    cy_stc_cryptolite_context_sha256_t sha_ctx;
    cy_en_cryptolite_sig_verify_result_t verResult;
    cy_en_cryptolite_status_t status;

    verResult = CY_CRYPTOLITE_SIG_INVALID;
    memset((void*)&decryptedSignature, 0u, sizeof(decryptedSignature));
    memset((void*)&calculatedHash, 0u, sizeof(calculatedHash));
    memset((void*)&rsa_buffer, 0u, sizeof(rsa_buffer));
    memset((void*)&rsa_ctx, 0u, sizeof(rsa_ctx));
    memset((void*)&sha_ctx, 0u, sizeof(sha_ctx));

    Cy_Cryptolite_InvertEndianness(modulus_2048, 2048u/8 );
    Cy_Cryptolite_InvertEndianness(encryptedSignature_2048, sizeof(encryptedSignature_2048) );

    Cy_Cryptolite_InvertEndianness(publicExponent, sizeof(publicExponent));

    cy_stc_cryptolite_rsa_pub_key_t pubKeyPtr =
    {
        .moduloPtr          = modulus_2048,
        .moduloLength       = 2048u,
        .pubExpPtr          = publicExponent,
        .pubExpLength       = sizeof(publicExponent)* 8,       /* 17 bits */
        .barretCoefPtr       = barretCoef,
        .inverseModuloPtr    = inverseModulo,
        .rBarPtr             = rBar,
        .preCalculatedCoeff  = false
    };

    status = Cy_Cryptolite_Rsa_Init(CRYPTOLITE, &rsa_ctx, &rsa_buffer);

    /* ... check for errors... */

    /* At first decrypt the received signature. */
    status = Cy_Cryptolite_Rsa_Proc(CRYPTOLITE, &rsa_ctx, &pubKeyPtr, encryptedSignature_2048, 2048u, decryptedSignature);

    /* ... check for errors... */

    /* Calculate the hash from the plain text */
    status = Cy_Cryptolite_Sha256_Run(CRYPTOLITE, plainTxt, sizeof(plainTxt)-1, calculatedHash, &sha_ctx);

    /* ... check for errors... */

    Cy_Cryptolite_InvertEndianness(decryptedSignature, sizeof(encryptedSignature_2048));

    /* Finally verify decrypted signature with calculated digest */
    status = Cy_Cryptolite_Rsa_Verify(CRYPTOLITE, &rsa_ctx, &verResult, CY_CRYPTOLITE_MODE_SHA256, calculatedHash, sizeof(calculatedHash), decryptedSignature, sizeof(encryptedSignature_2048));

    /* ... check for errors... */

    Cy_Cryptolite_Rsa_Free(CRYPTOLITE, &rsa_ctx);

    /* ... check verResult is CY_CRYPTOLITE_SIG_VALID... */