void DH_generate_key(DH_CTX *dh_ctx)
{
BI_CTX *bi_ctx = bi_initialize();
int len = dh_ctx->len;
bigint *p = bi_import(bi_ctx, dh_ctx->p, len); //p modulus
bigint *g = bi_import(bi_ctx, dh_ctx->g, dh_ctx->glen); //generator
bigint *x, *gx;
bi_permanent(g);
//generate private key X
get_random_NZ(len, dh_ctx->x);
x = bi_import(bi_ctx, dh_ctx->x, len);
bi_permanent(x);
//calculate public key gx = g^x mod p
bi_set_mod(bi_ctx, p, BIGINT_M_OFFSET);
bi_ctx->mod_offset = BIGINT_M_OFFSET;
gx = bi_mod_power(bi_ctx, g, x);
bi_permanent(gx);
bi_export(bi_ctx, x, dh_ctx->x, len);
bi_export(bi_ctx, gx, dh_ctx->gx, len);
bi_depermanent(g);
bi_depermanent(x);
bi_depermanent(gx);
bi_free(bi_ctx, g);
bi_free(bi_ctx, x);
bi_free(bi_ctx, gx);
bi_free_mod(bi_ctx, BIGINT_M_OFFSET);
bi_terminate(bi_ctx);
}
/**
* Use PKCS1.5 for encryption/signing.
* see http://www.rsasecurity.com/rsalabs/node.asp?id=2125
*/
int RSA_encrypt(const RSA_CTX *ctx, const uint8_t *in_data, uint16_t in_len,
uint8_t *out_data, int is_signing)
{
int byte_size = ctx->num_octets;
int num_pads_needed = byte_size-in_len-3;
bigint *dat_bi, *encrypt_bi;
/* note: in_len+11 must be > byte_size */
out_data[0] = 0; /* ensure encryption block is < modulus */
if (is_signing)
{
out_data[1] = 1; /* PKCS1.5 signing pads with "0xff"'s */
memset(&out_data[2], 0xff, num_pads_needed);
}
else /* randomize the encryption padding with non-zero bytes */
{
out_data[1] = 2;
if (get_random_NZ(num_pads_needed, &out_data[2]) < 0)
return -1;
}
out_data[2+num_pads_needed] = 0;
memcpy(&out_data[3+num_pads_needed], in_data, in_len);
/* now encrypt it */
dat_bi = bi_import(ctx->bi_ctx, out_data, byte_size);
encrypt_bi = is_signing ? RSA_private(ctx, dat_bi) :
RSA_public(ctx, dat_bi);
bi_export(ctx->bi_ctx, encrypt_bi, out_data, byte_size);
/* save a few bytes of memory */
bi_clear_cache(ctx->bi_ctx);
return byte_size;
}
/**
* Use PKCS1.5 for encryption/signing.
* see http://www.rsasecurity.com/rsalabs/node.asp?id=2125
*/
int RSA_encrypt(const RSA_CTX *ctx, const uint8_t *in_data, uint16_t in_len,
uint8_t *out_data, int is_signing)
{
int byte_size = ctx->num_octets;printf("byte_size:%d\n",byte_size);
int num_pads_needed = byte_size-in_len-3;printf("num_pads_needed:%d\n",num_pads_needed);
bigint *dat_bi, *encrypt_bi;
/* note: in_len+11 must be > byte_size */
out_data[0] = 0; /* ensure encryption block is < modulus */
if (is_signing)
{
out_data[1] = 1; /* PKCS1.5 signing pads with "0xff"'s */
memset(&out_data[2], 0xff, num_pads_needed);
}
else /* randomize the encryption padding with non-zero bytes */
{
out_data[1] = 2;
get_random_NZ(num_pads_needed, &out_data[2]);
}
out_data[2+num_pads_needed] = 0;
memcpy(&out_data[3+num_pads_needed], in_data, in_len);
/* now encrypt it */
dat_bi = bi_import(ctx->bi_ctx, out_data, byte_size);
bi_print("pre_dispose_data",dat_bi);
encrypt_bi = is_signing ? RSA_private(ctx, dat_bi) :
RSA_public(ctx, dat_bi);
bi_export(ctx->bi_ctx, encrypt_bi, out_data, byte_size);
int i=0;
printf("encrypted message in uint8_t:");
for (i;i<byte_size;i++)
printf("0x%02x ",out_data[i]);
printf("\n\n");
return byte_size;
}
