/*
rsa oaep encryption
*/
unsigned char *rsacrypt(pk_context *pkctx,const unsigned char *plaintext,const unsigned int plaintextsize){
entropy_context entropy = {0};
ctr_drbg_context ctr_drbg = {0};
rsa_context rsactx = {0};
int pkresult = 0;
unsigned char *encryptedoutput = NULL;
unsigned int encryptedoutputsize = 0;
char pers[33] = "3s:!2OXI(FX%#Q($[CEjiGRIk\\-)4e&?";
int ret = 0;
entropy_init( &entropy );
if((ret = ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, (unsigned char *)&pers[0],strlen(pers))) != 0 ){
outputerror(DBG_ERROR,"%s\n","rsacrypt::failed to initialize random generator");
return NULL;
}
encryptedoutputsize = pk_get_len(pkctx);
outputerror(DBG_INFO,"%s %Iu\n","rsacrypt::buffer size for rsa encrypted output ",encryptedoutputsize);
encryptedoutput = (unsigned char *)malloc(encryptedoutputsize);
SecureZeroMemory(encryptedoutput,encryptedoutputsize);
rsa_copy(&rsactx,pkctx->pk_ctx);
rsactx.padding = RSA_PKCS_V21;
rsactx.hash_id = POLARSSL_MD_SHA1;
pkresult = 0;
pkresult = rsa_rsaes_oaep_encrypt(&rsactx,ctr_drbg_random,&ctr_drbg,RSA_PUBLIC,"cryptoshot",strlen("cryptoshot"),plaintextsize,plaintext,encryptedoutput);
if(pkresult != 0){
outputerror(DBG_ERROR,"%s %i\n","rsacrypt::failed to encrypt data",pkresult);
return NULL;
}
entropy_free(&entropy);
rsa_free(&rsactx);
return encryptedoutput;
}
/*
* Add the message padding, then do an RSA operation
*/
int rsa_pkcs1_encrypt( rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode, size_t ilen,
const unsigned char *input,
unsigned char *output )
{
switch( ctx->padding )
{
#if defined(POLARSSL_PKCS1_V15)
case RSA_PKCS_V15:
return rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen,
input, output );
#endif
#if defined(POLARSSL_PKCS1_V21)
case RSA_PKCS_V21:
return rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0,
ilen, input, output );
#endif
default:
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
}
