/* ECC Public x963 Export */
int CRYPT_ECC_PublicExport(CRYPT_ECC_CTX* ecc, unsigned char* out,
unsigned int outSz, unsigned int* usedSz)
{
int ret;
unsigned int inOut = outSz;
if (ecc == NULL || out == NULL)
return BAD_FUNC_ARG;
ret = wc_ecc_export_x963((ecc_key*)ecc->holder, out, &inOut);
*usedSz = inOut;
return ret;
}
int main()
{
ecc_key key;
byte der[4096];
byte buf[4096];
word32 idx = 0;
FILE* derFile;
size_t sz;
RNG rng;
wc_InitRng(&rng);
wc_ecc_init(&key);
if (wc_ecc_make_key(&rng, 32, &key) != 0) {
printf("error making ecc key\n");
return -1;
}
/* write private key */
if (wc_EccKeyToDer(&key, der, sizeof(der)) < 0) {
printf("error in ecc to der\n");
return -1;
}
printf("writing private key to ecc-key.der\n");
derFile = fopen("ecc-key.der", "w");
if (!derFile) {
printf("error loading file\n");
return -1;
}
sz = fwrite(der, 1, 4096, derFile);
fclose(derFile);
wc_ecc_free(&key);
/* open and read from der file */
printf("reading in private key\n");
derFile = fopen("ecc-key.der", "rb");
if (!derFile) {
printf("error reading from file\n");
return -1;
}
sz = fread(buf, 1, 4096, derFile);
fclose(derFile);
/* load private ecc key */
printf("storing private key in ecc struct\n");
wc_ecc_init(&key);
if (wc_EccPrivateKeyDecode(buf, &idx, &key, (word32)sz) != 0) {
printf("error decoding private key\n");
return -1;
}
wc_ecc_free(&key);
/* Or the der file can be loaded into a TLS connection using something like
int wc_DerToPem(der, sizeof(der), pemOut, sizeof(pemOut),
ECC_PRIVATEKEY_TYPE);
int wolfSSL_use_PrivateKey_file(&ssl, pemOut, SSL_FILETYPE_PEM);
*/
/* to store a public key */
wc_ecc_init(&key);
if (wc_ecc_make_key(&rng, 32, &key) != 0) {
printf("error making ecc key\n");
return -1;
}
printf("storing public key into ecc-public.x963\n");
memset(buf, 0, sizeof(buf));
idx = sizeof(buf);
if (wc_ecc_export_x963(&key, buf, &idx) != 0) {
printf("error exporting public ecc key\n");
return -1;
}
derFile = fopen("ecc-public.x963", "w"); /* reused the derFile pointer */
if (!derFile) {
printf("error loading file\n");
return -1;
}
sz = fwrite(buf, 1, idx, derFile);
/* close stuff up */
fclose(derFile);
wc_ecc_free(&key);
wc_FreeRng(&rng);
return 0;
}
int ecc_sign_verify_test(enum wc_HashType hash_type,
enum wc_SignatureType sig_type, const byte* fileBuf, int fileLen,
byte* verifyFileBuf, int* verifyFileLen, int* pmaxSigSz, int* pmaxCurveSigSz,
int curveId, int keySz)
{
int ret;
ecc_key eccKey;
RNG rng;
byte* sigBuf = NULL;
word32 sigLen;
byte eccPubKeyBuf[ECC_BUFSIZE], eccPrivKeyBuf[ECC_BUFSIZE];
word32 eccPubKeyLen, eccPrivKeyLen;
word32 maxCurveSigSz;
#ifdef DEBUG_SIG_TEST
printf("ECC Signature: Curve %s, Size %d\n", wc_ecc_get_name(curveId), keySz);
#endif
/* Init */
wc_InitRng(&rng);
/* Generate key */
wc_ecc_init(&eccKey);
ret = wc_ecc_make_key_ex(&rng, keySz, &eccKey, curveId);
if(ret != 0) {
printf("ECC Make Key Failed! %d\n", ret);
goto exit;
}
ret = wc_ecc_sig_size(&eccKey);
if (ret < 0) {
printf("ECC Sig SizeFailed! %d\n", ret);
goto exit;
}
maxCurveSigSz = ret;
/* Display public key data */
eccPubKeyLen = ECC_BUFSIZE;
ret = wc_ecc_export_x963(&eccKey, eccPubKeyBuf, &eccPubKeyLen);
if (ret != 0) {
printf("ECC public key x963 export failed! %d\n", ret);
ret = EXIT_FAILURE;
goto exit;
}
#ifdef DEBUG_SIG_TEST
printf("ECC Public Key: Len %d\n", eccPubKeyLen);
hexdump(eccPubKeyBuf, eccPubKeyLen, 16);
#endif
/* Display private key data */
eccPrivKeyLen = ECC_BUFSIZE;
ret = wc_ecc_export_private_only(&eccKey, eccPrivKeyBuf, &eccPrivKeyLen);
if (ret != 0) {
printf("ECC private key export failed! %d\n", ret);
ret = EXIT_FAILURE;
goto exit;
}
#ifdef DEBUG_SIG_TEST
printf("ECC Private Key: Len %d\n", eccPrivKeyLen);
hexdump(eccPrivKeyBuf, eccPrivKeyLen, 16);
#endif
if (verifyFileBuf) {
sigLen = *verifyFileLen;
sigBuf = verifyFileBuf;
}
else {
/* Get signature length and allocate buffer */
sigLen = wc_SignatureGetSize(sig_type, &eccKey, sizeof(eccKey));
if(sigLen <= 0) {
printf("ECC Signature type %d not supported!\n", sig_type);
ret = EXIT_FAILURE;
goto exit;
}
sigBuf = malloc(sigLen);
if(!sigBuf) {
printf("ECC Signature malloc failed!\n");
ret = EXIT_FAILURE;
goto exit;
}
#ifdef DEBUG_SIG_TEST
printf("ECC Signature Len: %d\n", sigLen);
#endif
/* Perform hash and sign to create signature */
ret = wc_SignatureGenerate(
hash_type, sig_type,
fileBuf, fileLen,
sigBuf, &sigLen,
&eccKey, sizeof(eccKey),
&rng);
*verifyFileLen = sigLen;
#ifdef DEBUG_SIG_TEST
printf("ECC Signature Generation: %s (%d)\n",
(ret == 0) ? "Pass" : "Fail", ret);
#endif
if(ret < 0) {
ret = EXIT_FAILURE;
goto exit;
}
}
#ifdef DEBUG_SIG_TEST
printf("Signature Data:\n");
hexdump(sigBuf, sigLen, 16);
#endif
/* Perform signature verification */
/* Release and init new key */
wc_ecc_free(&eccKey);
wc_ecc_init(&eccKey);
/* Import the public key */
ret = wc_ecc_import_x963_ex(eccPubKeyBuf, eccPubKeyLen, &eccKey, curveId);
if (ret != 0) {
printf("ECC public key import failed! %d\n", ret);
ret = EXIT_FAILURE;
goto exit;
}
/* Perform signature verification using public key */
ret = wc_SignatureVerify(
hash_type, sig_type,
fileBuf, fileLen,
sigBuf, sigLen,
&eccKey, sizeof(eccKey));
#ifdef DEBUG_SIG_TEST
printf("ECC Signature Verification: %s (%d)\n",
(ret == 0) ? "Pass" : "Fail", ret);
#endif
if (ret < 0) {
ret = EXIT_FAILURE;
}
if (pmaxSigSz && *pmaxSigSz < sigLen) {
#ifdef DEBUG_SIG_TEST_MAX
printf("Curve: Max %d->%d\n", *pmaxSigSz, sigLen);
hexdump(sigBuf, sigLen, 16);
#endif
*pmaxSigSz = sigLen;
}
if (pmaxCurveSigSz && *pmaxCurveSigSz < maxCurveSigSz) {
*pmaxCurveSigSz = maxCurveSigSz;
}
exit:
/* Free */
if(sigBuf) {
free(sigBuf);
}
wc_ecc_free(&eccKey);
wc_FreeRng(&rng);
return ret;
}
int main(int argc, char** argv)
{
int ret;
WC_RNG rng;
ecEncCtx* srvCtx = NULL;
void* devCtx = NULL;
const byte* mySalt;
byte peerSalt[EXCHANGE_SALT_SZ];
byte buffer[BTLE_MSG_MAX_SIZE];
word32 bufferSz;
byte plain[BTLE_MSG_MAX_SIZE];
word32 plainSz;
ecc_key myKey, peerKey;
int type;
wolfSSL_Init();
#ifdef DEBUG_WOLFSSL
wolfSSL_Debugging_ON();
#endif
/* make my session key */
ret = wc_ecc_init(&myKey);
ret |= wc_ecc_init(&peerKey);
if (ret != 0) {
printf("wc_ecc_init failed!\n");
goto cleanup;
}
/* open BTLE */
ret = btle_open(&devCtx, BTLE_ROLE_SERVER);
if (ret != 0) {
printf("btle_open failed %d! errno %d\n", ret, errno);
goto cleanup;
}
ret = wc_InitRng(&rng);
if (ret != 0) {
printf("wc_InitRng failed! %d\n", ret);
goto cleanup;
}
ret = wc_ecc_make_key(&rng, 32, &myKey);
if (ret != 0) {
printf("wc_ecc_make_key failed %d\n", ret);
goto cleanup;
}
srvCtx = wc_ecc_ctx_new(REQ_RESP_SERVER, &rng);
if (srvCtx == NULL) {
printf("wc_ecc_ctx_new failed!\n");
ret = -1; goto cleanup;
}
/* exchange public keys */
/* Get peer key */
ret = btle_recv(buffer, sizeof(buffer), &type, devCtx);
if (ret < 0) {
printf("btle_recv key failed %d! errno %d\n", ret, errno);
goto cleanup;
}
if (type != BTLE_PKT_TYPE_KEY) {
printf("btle_recv expected key!\n");
ret = -1; goto cleanup;
}
bufferSz = ret;
ret = wc_ecc_import_x963(buffer, bufferSz, &peerKey);
if (ret != 0) {
printf("wc_ecc_import_x963 failed %d!\n", ret);
goto cleanup;
}
/* send my public key */
/* export my public key */
bufferSz = sizeof(buffer);
ret = wc_ecc_export_x963(&myKey, buffer, &bufferSz);
if (ret != 0) {
printf("wc_ecc_export_x963 failed %d\n", ret);
goto cleanup;
}
/* TODO: Server should hash and sign this public key with a trust ceritifcate (already exchanged) */
/* ECC signature is about 65 bytes */
ret = btle_send(buffer, bufferSz, BTLE_PKT_TYPE_KEY, devCtx);
if (ret != bufferSz) {
printf("btle_send key failed %d!\n", ret);
goto cleanup;
}
while (1) {
mySalt = wc_ecc_ctx_get_own_salt(srvCtx);
if (mySalt == NULL) {
printf("wc_ecc_ctx_get_own_salt failed!\n");
ret = -1; goto cleanup;
}
/* Get peer salt */
ret = btle_recv(peerSalt, EXCHANGE_SALT_SZ, &type, devCtx);
if (ret <= 0) {
printf("btle_recv salt failed %d! errno %d\n", ret, errno);
goto cleanup;
}
if (type != BTLE_PKT_TYPE_SALT) {
printf("btle_recv expected salt!\n");
ret = -1; goto cleanup;
}
/* Send my salt */
/* You must send mySalt before set_peer_salt, because buffer changes */
ret = btle_send(mySalt, EXCHANGE_SALT_SZ, BTLE_PKT_TYPE_SALT, devCtx);
if (ret != EXCHANGE_SALT_SZ) {
printf("btle_send salt failed %d!\n", ret);
goto cleanup;
}
ret = wc_ecc_ctx_set_peer_salt(srvCtx, peerSalt);
if (ret != 0) {
printf("wc_ecc_ctx_set_peer_salt failed %d\n", ret);
goto cleanup;
}
/* Get message */
bufferSz = sizeof(buffer);
ret = btle_recv(buffer, bufferSz, &type, devCtx);
if (ret <= 0) {
printf("btle_recv msg failed %d! errno %d\n", ret, errno);
goto cleanup;
}
if (type != BTLE_PKT_TYPE_MSG) {
printf("btle_recv expected msg!\n");
ret = -1; goto cleanup;
}
/* Decrypt message */
bufferSz = ret;
plainSz = sizeof(plain);
ret = wc_ecc_decrypt(&myKey, &peerKey, buffer, bufferSz, plain, &plainSz, srvCtx);
if (ret != 0) {
printf("wc_ecc_decrypt failed %d!\n", ret);
goto cleanup;
}
printf("Recv %d: %s\n", plainSz, plain);
/* Encrypt message */
bufferSz = sizeof(buffer);
ret = wc_ecc_encrypt(&myKey, &peerKey, plain, plainSz, buffer, &bufferSz, srvCtx);
if (ret != 0) {
printf("wc_ecc_encrypt failed %d!\n", ret);
goto cleanup;
}
/* Send message */
ret = btle_send(buffer, bufferSz, BTLE_PKT_TYPE_MSG, devCtx);
if (ret != bufferSz) {
printf("btle_send failed %d!\n", ret);
goto cleanup;
}
/* check for exit flag */
if (strstr((char*)plain, "EXIT"))
break;
/* reset context (reset my salt) */
ret = wc_ecc_ctx_reset(srvCtx, &rng);
if (ret != 0) {
printf("wc_ecc_ctx_reset failed %d\n", ret);
goto cleanup;
}
}
cleanup:
if (devCtx != NULL)
btle_close(devCtx);
wolfSSL_Cleanup();
return ret;
}