Functions

General Description

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_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_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... */