Signature API
Functions
Name | |
---|---|
int | wc_SignatureGetSize(enum wc_SignatureType sig_type, const void * key, word32 key_len) This function returns the maximum size of the resulting signature. |
int | wc_SignatureVerify(enum wc_HashType hash_type, enum wc_SignatureType sig_type, const byte * data, word32 data_len, const byte * sig, word32 sig_len, const void * key, word32 key_len) This function validates a signature by hashing the data and using the resulting hash and key to verify the signature. |
int | wc_SignatureGenerate(enum wc_HashType hash_type, enum wc_SignatureType sig_type, const byte * data, word32 data_len, byte * sig, word32 * sig_len, const void * key, word32 key_len, WC_RNG * rng) This function generates a signature from the data using a key. It first creates a hash of the data then signs the hash using the key. |
Functions Documentation
function wc_SignatureGetSize
int wc_SignatureGetSize(
enum wc_SignatureType sig_type,
const void * key,
word32 key_len
)
This function returns the maximum size of the resulting signature.
Parameters:
- sig_type A signature type enum value such as WC_SIGNATURE_TYPE_ECC or WC_SIGNATURE_TYPE_RSA.
- key Pointer to a key structure such as ecc_key or RsaKey.
- key_len Size of the key structure.
See:
Return: Returns SIG_TYPE_E if sig_type is not supported. Returns BAD_FUNC_ARG if sig_type was invalid. A positive return value indicates the maximum size of a signature.
Example
// Get signature length
enum wc_SignatureType sig_type = WC_SIGNATURE_TYPE_ECC;
ecc_key eccKey;
word32 sigLen;
wc_ecc_init(&eccKey);
sigLen = wc_SignatureGetSize(sig_type, &eccKey, sizeof(eccKey));
if (sigLen > 0) {
// Success
}
function wc_SignatureVerify
int wc_SignatureVerify(
enum wc_HashType hash_type,
enum wc_SignatureType sig_type,
const byte * data,
word32 data_len,
const byte * sig,
word32 sig_len,
const void * key,
word32 key_len
)
This function validates a signature by hashing the data and using the resulting hash and key to verify the signature.
Parameters:
- hash_type A hash type from the “enum wc_HashType” such as “WC_HASH_TYPE_SHA256”.
- sig_type A signature type enum value such as WC_SIGNATURE_TYPE_ECC or WC_SIGNATURE_TYPE_RSA.
- data Pointer to buffer containing the data to hash.
- data_len Length of the data buffer.
- sig Pointer to buffer to output signature.
- sig_len Length of the signature output buffer.
- key Pointer to a key structure such as ecc_key or RsaKey.
- key_len Size of the key structure.
See:
Return:
- 0 Success
- SIG_TYPE_E -231, signature type not enabled/ available
- BAD_FUNC_ARG -173, bad function argument provided
- BUFFER_E -132, output buffer too small or input too large.
Example
int ret;
ecc_key eccKey;
// Import the public key
wc_ecc_init(&eccKey);
ret = wc_ecc_import_x963(eccPubKeyBuf, eccPubKeyLen, &eccKey);
// Perform signature verification using public key
ret = wc_SignatureVerify(
WC_HASH_TYPE_SHA256, WC_SIGNATURE_TYPE_ECC,
fileBuf, fileLen,
sigBuf, sigLen,
&eccKey, sizeof(eccKey));
printf("Signature Verification: %s
(%d)\n", (ret == 0) ? "Pass" : "Fail", ret);
wc_ecc_free(&eccKey);
function wc_SignatureGenerate
int wc_SignatureGenerate(
enum wc_HashType hash_type,
enum wc_SignatureType sig_type,
const byte * data,
word32 data_len,
byte * sig,
word32 * sig_len,
const void * key,
word32 key_len,
WC_RNG * rng
)
This function generates a signature from the data using a key. It first creates a hash of the data then signs the hash using the key.
Parameters:
- hash_type A hash type from the “enum wc_HashType” such as “WC_HASH_TYPE_SHA256”.
- sig_type A signature type enum value such as WC_SIGNATURE_TYPE_ECC or WC_SIGNATURE_TYPE_RSA.
- data Pointer to buffer containing the data to hash.
- data_len Length of the data buffer.
- sig Pointer to buffer to output signature.
- sig_len Length of the signature output buffer.
- key Pointer to a key structure such as ecc_key or RsaKey.
- key_len Size of the key structure.
- rng Pointer to an initialized RNG structure.
See:
Return:
- 0 Success
- SIG_TYPE_E -231, signature type not enabled/ available
- BAD_FUNC_ARG -173, bad function argument provided
- BUFFER_E -132, output buffer too small or input too large.
Example
int ret;
WC_RNG rng;
ecc_key eccKey;
wc_InitRng(&rng);
wc_ecc_init(&eccKey);
// Generate key
ret = wc_ecc_make_key(&rng, 32, &eccKey);
// Get signature length and allocate buffer
sigLen = wc_SignatureGetSize(sig_type, &eccKey, sizeof(eccKey));
sigBuf = malloc(sigLen);
// Perform signature verification using public key
ret = wc_SignatureGenerate(
WC_HASH_TYPE_SHA256, WC_SIGNATURE_TYPE_ECC,
fileBuf, fileLen,
sigBuf, &sigLen,
&eccKey, sizeof(eccKey),
&rng);
printf("Signature Generation: %s
(%d)\n", (ret == 0) ? "Pass" : "Fail", ret);
free(sigBuf);
wc_ecc_free(&eccKey);
wc_FreeRng(&rng);
Updated on 2024-08-30 at 01:18:19 +0000