static crypto_error_t crypto_pad(bytestring_t *dst, const bytestring_t *ctx,const bytestring_t *src)
{
unsigned char e;
bytestring_copy(dst,src);
bytestring_get_element(&e,ctx,1);
switch (((unsigned)e)<<8)
{
case CRYPTO_PAD_OPT_80_ZERO:
if ((bytestring_get_size(dst)&0x7)==0)
break;
case CRYPTO_PAD_ISO9797_P2:
bytestring_pushback(dst,0x80);
bytestring_pad_right(dst,8,0);
break;
case CRYPTO_PAD_ZERO:
bytestring_pad_right(dst,8,0);
break;
default:
bytestring_clear(dst);
return CRYPTO_ERROR_UNKNOWN_PADDING_METHOD;
}
return CRYPTO_OK;
}
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;
}
bytestring_t* bytestring_new_from_hex(const char *hex)
{
bytestring_t *dat=bytestring_new();
unsigned hex_len=strlen(hex);
unsigned c;
size_t i=0;
bytestring_reserve(dat,hex_len/2);
while (i<hex_len)
{
if (is_blank(hex[i]))
{
i++;
continue;
}
c=(hex_nibble(hex[i])<<4) | hex_nibble(hex[i+1]);
if (c>255)
return dat;
bytestring_pushback(dat,(unsigned char)c);
i+=2;
}
return dat;
}