I'm trying to revoke user by JAVA SDK
String crl = caClient.revoke(revoker, userToRevoke, "removefromcrl", true);
After executed the above line userToRevoke can still query and invoke normally. Why is it like that?
and what should I do next with this crl string?
Your nodes must update periodically the crls folder under their MSP folder. Otherwise, revoked certificates cannot be detected by the MSP.
https://hyperledger-fabric.readthedocs.io/en/latest/msp.html#msp-setup-on-the-peer-orderer-side
https://hyperledger-fabric-ca.readthedocs.io/en/latest/users-guide.html#generating-a-crl-certificate-revocation-list
And they should also be updated in the channel configuration, which is even more tedious.
Related
What is the procedure of replacing a root CA cert with another one of a different key pair.
Q-1 : Is that required to follow config update steps to do as we do in add/remove org, since RCA need to change?
(Understood that changing the RCA require to reCreate all peers,nodes, identities as well)
When we use the default setup of fabric CA, then
it bootstraps the fabric ca server with bootstrap administrator - 'fabric-ca-server start -b admin:adminpw -d'
On enrolling the bootstrap administrator -
It creates the following in msp : cacerts, Keystore, sign certs (Set-A)
now when we have to create identities then it uses Set-A, and all such stuff also got bind to the genesis block as well, as certificate got configured via ConfigTX file, and that got stored in the config channel of fabric.
Q-2 : Now If we have to change the RCA's cacerts, Keystore, sign certs (Set-B), then what is the procedure to do that ?
Not found any guidelines or documents on this, It's just logically understood if that is possible then maybe follow the similar steps as we do in add/remove orgs.
Q-3: But even to replace all identities with new RCA along with RCA's cert, key pair etc, then I don't think existing data may work?
if the live network already has x data, but RCA's cacerts, Keystore, sign certs and all identities got changed and also updated the config file with config-update way as we do in add/remove orgs so it has new certificate info ?
I noticed that HLf admincerts and tls certs, by default, have an expiration date of 1 year. In my case, they have expired and my orderer and peer nodes are giving me a bad certificate error.
Is there any way to do certificate rotation? I don't want to loose any data as the network is in a production enviroment. I am using hyperledger fabric 1.4 version with the raft ordering service.
You can change the default expiry time of an x509 certificate by changing its duration in the fabric-ca-server configuration file. You'll find this file inside CA's docker container.
Reference to the fabric-ca-server configuration file can be found here.
Change the value of expiry from 8760h to xxxx in the signing section of the file. signing section looks like this:
signing:
default:
usage:
- digital signature
expiry: 8760h
profiles:
ca:
usage:
- cert sign
- crl sign
expiry: 43800h
caconstraint:
isca: true
maxpathlen: 0
tls:
usage:
- signing
- key encipherment
- server auth
- client auth
- key agreement
expiry: 8760h
After changing the value of expiry, you'll have to restart your CA container for the changes to take effect.
Once your container is restarted, re-enroll your admin to create a new x509 certificate with the updated expiry duration. You can read about reenrolling an identity from here.
If you want to avoid such scenarios in the future for any user, you can reenroll it before doing a transaction. You can perform the re-enroll operation if the certificate has already expired or going to expire in the next x amount of time.
I am on fabric v2.3 and using Fabric CA.
When we re-enroll the peers, orderer or admin it will generate a new pair of certifcates.
Please correct me if i am wrong, these newly generated certificates needs to be updated in the channel configuration as well? At least this is what the doc says here
I tried to follow the doc and it does contains the root_certs and tls_certs which we need to replace. A usual sample config block after decoding it into json files looks something like this. The respective certs needs to replaced here which seems quite error prone since it's manual and a lot of certs needs to be replaced (depending on the number of peers, orderers, and organisations you've got). And, also not to forget these certs are referenced by the ccp.yaml and ccp.json as well which is used by the fabric sdk.
I am not sure if my understanding is correct about this, as I am struggling with this thing as well. I haven't been able to successfully pull this of as of now. It's strange that hyperledger fabric/Fabric CA doesn't really has a straightforward way of doing this.
Our case: k8s, fabric v2.2, mutual tls requied for all hyperledger connections, certificates expired 3 days ago.
First of all we need to pass through expired tls. Add to the orderer config:
ORDERER_GENERAL_TLS_TLSHANDSHAKETIMESHIFT: 120h
ORDERER_GENERAL_AUTHENTICATION_NOEXPIRATIONCHECKS: "true"
The latest parameter will allow to use expired MSP entities later.
To skip tls checks on the peer side, use the --tlsHandshakeTimeShift 120h parameter.
After the connection was restored, we need to update certificates in the blockchain. Unfortunately there is no analog of the _NOEXPIRATIONCHECKS option for the peer, so we need to use a time-shifted environment. I didn't manage to run the one in the kubernetes, so I had to use a notebook with ntp disabled and port-forwarded orderer endpoint. Be aware that if your kubernetes authentication is token-based, it can stop working because of having the incorrect time. In Azure, this is fixed by getting admin config.
That environment should be enough for step-by-step replaying of your standard certificate rotating scripts. If you don't have any, dive into this issue.
I am trying to make following function with customized tokens. The goal is to mint tokens including metadata which is only exposed to the owner of token. This means that no one is permitted to read the metadata other than the owner. Is it possible to create such tokens?
Thank you.
You can implement that with Attribute Based Access Control with the help of Hyperledger Fabric CA, Chaincode's client identity library and some programming related key management techniques.
In Chaincode Side:
To store metadata, the chaincode will get the owner/user certificate with the help of client identity library and by parsing that certificate, chaincode will get certificate user's/owner's public key and hold the public key with a variable named as "variablePublicKey" and after that will store it's metadata with key "variablePublicKey.metadata".
To read the metadata, the chaincode will get the owner/user certificate with the help of client identity library and by parsing that certificate, chaincode will get certificate user's/owner's public key and hold the public key with a variable named as "variablePublicKey" and after that will get it's metadata with key "variablePublicKey.metadata".
To ensure security with this system, your chaincode must need to add some substring with each of user Input key. For example if user want to invoke or to query a car type asset, the chaincode will always add a substring with that user input, like user input key is "xyz" so the chaincode will add a substring with that like "xyz.car" and store/update value against the "xyz.car" key. To query a car, if the user give the input as "xyz", the chaincode will add a substring with that like "xyz.car" and query value against the "xyz.car" key
This is a theoretical question about certificate validation in Hyperledger Fabric. How does Fabric handle a scenario like a compromised certificate authority? Does it monitor public log servers to ensure a certificate is valid?
Certificate Revocation Lists
A Certificate Revocation List (CRL) is easy to understand — it’s just a list of references to certificates that a CA knows to be revoked for one reason or another. If you recall the store scenario, a CRL would be like a list of stolen credit cards.
When a third party wants to verify another party’s identity, it first checks the issuing CA’s CRL to make sure that the certificate has not been revoked. A verifier doesn’t have to check the CRL, but if they don’t they run the risk of accepting a compromised identity.
Using a CRL to check that a certificate is still valid. If an impersonator tries to pass a compromised digital certificate to a validating party, it can be first checked against the issuing CA’s CRL to make sure it’s not listed as no longer valid.
link: https://hyperledger-fabric.readthedocs.io/en/release-2.2/identity/identity.html#certificate-revocation-lists
Generating a CRL (Certificate Revocation List)
After a certificate is revoked in the Fabric CA server, the appropriate MSPs in Hyperledger Fabric must also be updated. This includes both local MSPs of the peers as well as MSPs in the appropriate channel configuration blocks. To do this, PEM encoded CRL (certificate revocation list) file must be placed in the crls folder of the MSP. The fabric-ca-client gencrl command can be used to generate a CRL. Any identity with hf.GenCRL attribute can create a CRL that contains serial numbers of all certificates that were revoked during a certain period. The created CRL is stored in the /crls/crl.pem file.
The following command will create a CRL containing all the revoked certficates (expired and unexpired) and store the CRL in the ~/msp/crls/crl.pem file.
export FABRIC_CA_CLIENT_HOME=~/clientconfig
fabric-ca-client gencrl -M ~/msp
The next command will create a CRL containing all certificates (expired and unexpired) that were revoked after 2017-09-13T16:39:57-08:00 (specified by the –revokedafter flag) and before 2017-09-21T16:39:57-08:00 (specified by the –revokedbefore flag) and store the CRL in the ~/msp/crls/crl.pem file.
export FABRIC_CA_CLIENT_HOME=~/clientconfig
fabric-ca-client gencrl --caname "" --revokedafter 2017-09-13T16:39:57-08:00 --revokedbefore 2017-09-21T16:39:57-08:00 -M ~/msp
The –caname flag specifies the name of the CA to which this request is sent. In this example, the gencrl request is sent to the default CA.
The –revokedafter and –revokedbefore flags specify the lower and upper boundaries of a time period. The generated CRL will contain certificates that were revoked in this time period. The values must be UTC timestamps specified in RFC3339 format. The –revokedafter timestamp cannot be greater than the –revokedbefore timestamp.
By default, ‘Next Update’ date of the CRL is set to next day. The crl.expiry CA configuration property can be used to specify a custom value.
The gencrl command will also accept –expireafter and –expirebefore flags that can be used to generate a CRL with revoked certificates that expire during the period specified by these flags. For example, the following command will generate a CRL that contains certificates that were revoked after 2017-09-13T16:39:57-08:00 and before 2017-09-21T16:39:57-08:00, and that expire after 2017-09-13T16:39:57-08:00 and before 2018-09-13T16:39:57-08:00
export FABRIC_CA_CLIENT_HOME=~/clientconfig
fabric-ca-client gencrl --caname "" --expireafter 2017-09-13T16:39:57-08:00 --expirebefore 2018-09-13T16:39:57-08:00 --revokedafter 2017-09-13T16:39:57-08:00 --revokedbefore 2017-09-21T16:39:57-08:00 -M ~/msp
link: https://hyperledger-fabric-ca.readthedocs.io/en/release-1.4/users-guide.html#generating-a-crl-certificate-revocation-list
Besides that, Hyperledger Fabric provides Pluggable Consensus Protocol and the security is depends on your plugable MSP too.
Generating the public key but not able to generate the private key of admin user while registering a new user through REST services in blockchain network and also getting below mentioned error.
Error:Failed Error: Private key missing from key store. Can not
establish the signing identity for user admin.
Followed the below steps :
Created a network in hyperledger fabric.
Created new a node application to publish the rest services by
referring the existing "balance-transfer" application.
Then started the node application.
Testing the rest services url in postman tool.
Getting the above mentioned error while testing the url http://localhost:4000/users in Postman tool.
Error at code level:
app.js--->helper.js
let adminUserObj = await client.setUserContext({username: admins[0].username, password: admins[0].secret});
Please suggest.
Remove the folders holding key-value store for organizations -> fabric-client-kv-* from the balance-transfer fabric sample.
rm -rf fabric-client-kv-*
Then create the network again. This resolved the issue for me.
have you tried to restart the network completely? (by using the "runApp.sh" script for that?) Take a look inside this script to the restartNetwork() function, where the "fabric-client-kv-org" folders in your balance-transfer folder are removed.
Does it work?