80 lines
2.2 KiB
Go
80 lines
2.2 KiB
Go
package contract
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import (
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"errors"
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"strings"
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)
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type AcceptedContract struct {
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Hash string
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BlockCipher string
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BlockCipherMode string
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AsymetricCryptography string
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}
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func listContains(lst []string, elm string) bool {
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for _, elm_ := range lst {
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if elm == elm_ {
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return true
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}
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}
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return false
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}
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func joinAsError(msg []string) error {
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if len(msg) > 0 {
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return errors.New(strings.Join(msg, "\n"))
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}
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return nil
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}
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func getFirstItemInList1ThatIsAlsoInList2(lst1, lst2 []string) (string, error) {
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for _, elm := range lst1 {
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if listContains(lst2, elm) {
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return elm, nil
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}
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}
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return "", errors.New("no items in list1 is in list2")
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}
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func getBestBlockCipher(prvCtr *PrivateContract, pubCtr *PublicContract) (string, error) {
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if b, err := getFirstItemInList1ThatIsAlsoInList2(pubCtr.AcceptedBlockCyphers, prvCtr.AcceptedBlockCyphers); err != nil {
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return "", errors.New("cannot find a block cypher that satisfy both contracts")
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} else {
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return b, nil
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}
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}
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func getBestBlockCipherMode(prvCtr *PrivateContract, pubCtr *PublicContract) (string, error) {
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if m, err := getFirstItemInList1ThatIsAlsoInList2(pubCtr.AcceptedBlockCypherModes, prvCtr.AcceptedBlockCypherModes); err != nil {
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return "", errors.New("cannot find a block cypher mode that satisfy both contracts")
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} else {
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return m, nil
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}
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}
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func getBestHash(prvCtr *PrivateContract, pubCtr *PublicContract) (string, error) {
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if h, err := getFirstItemInList1ThatIsAlsoInList2(pubCtr.AcceptedHashes, prvCtr.AcceptedHashes); err != nil {
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return "", errors.New("cannot find a hash that satisfy both contracts")
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} else {
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return h, nil
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}
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}
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func GetAcceptedContract(prvCtr *PrivateContract, pubCtr *PublicContract) (*AcceptedContract, error) {
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ret := new(AcceptedContract)
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errs := make([]string, 0, 4)
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var err error
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if ret.Hash, err = getBestHash(prvCtr, pubCtr); err != nil {
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errs = append(errs, err.Error())
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}
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if ret.BlockCipher, err = getBestBlockCipher(prvCtr, pubCtr); err != nil {
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errs = append(errs, err.Error())
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}
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if ret.BlockCipherMode, err = getBestBlockCipherMode(prvCtr, pubCtr); err != nil {
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errs = append(errs, err.Error())
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}
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return ret, joinAsError(errs)
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}
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