crypto_error_t crypto_create_context(bytestring_t *ctx,
crypto_alg_t alg_type,
const bytestring_t *key_bin)
{
DES_key_schedule ks;
bytestring_clear(ctx);
bytestring_pushback(ctx,ALG_TYPE(alg_type));
bytestring_pushback(ctx,PAD_TYPE(alg_type)>>8);
switch (ALG_TYPE(alg_type))
{
case CRYPTO_ALG_DES_ECB:
case CRYPTO_ALG_DES_CBC:
if (key_bin==NULL || bytestring_get_size(key_bin)!=8 || key_bin->width!=8)
return CRYPTO_ERROR_BAD_KEY_FORMAT;
DES_set_key_unchecked((const_DES_cblock *)key_bin->data,&ks);
bytestring_append_data(ctx,DES_KS_SIZE,(unsigned char *)&ks);
break;
case CRYPTO_ALG_DES2_EDE_ECB:
case CRYPTO_ALG_DES2_EDE_CBC:
case CRYPTO_ALG_ISO9797_M3:
if (key_bin==NULL || bytestring_get_size(key_bin)!=16 || key_bin->width!=8)
return CRYPTO_ERROR_BAD_KEY_FORMAT;
DES_set_key_unchecked((const_DES_cblock *)key_bin->data,&ks);
bytestring_append_data(ctx,DES_KS_SIZE,(unsigned char *)&ks);
DES_set_key_unchecked((const_DES_cblock *)(key_bin->data+8),&ks);
bytestring_append_data(ctx,DES_KS_SIZE,(unsigned char *)&ks);
break;
case CRYPTO_ALG_SHA1:
/* nothing else to do */
break;
default:
return CRYPTO_ERROR_UNKNOWN_KEY_TYPE;
}
return CRYPTO_OK;
}
int bytestring_insert_data(bytestring_t *bs,
unsigned pos,
unsigned len, const unsigned char* data)
{
if (pos>=bs->len)
return bytestring_append_data(bs,len,data);
bytestring_resize(bs,bs->len+len);
memmove(bs->data+pos+len,bs->data+pos,len);
memcpy(bs->data,data,len);
return BYTESTRING_OK;
}
int bytestring_append(bytestring_t *bs,
const bytestring_t *extra)
{
return bytestring_append_data(bs,extra->len,extra->data);
}
