go-iprs

Go implementation of IPRS spec. Note: This module is a work in progress

Table of Contents

• Install
• Usage
• License

Install

go-iprs is a standard Go module which can be installed with:

go get github.com/ipfs/go-iprs

Note that go-iprs is packaged with Gx, so it is recommended to use Gx to install and use it (see Usage section).

Usage

IPRS Records are published to a path that consists of a validation CID (eg CID of a public key) and an ID, eg /iprs/<cid>/photos

The record value is the path to an IPLD node in the block store. It can be

• an IPFS path eg /ipfs/<B58hash>/some/path
• the raw bytes of a CID pointing to an IPLD node
• a CID in string format with an optional path, eg <cid>/some/path
• an IPNS path eg /ipns/<B58hash>/some/path or /ipns/ipfs.io/some/path
• an IPRS path eg /iprs/<cid>/photos/3/size or /iprs/ipfs.io/some/path

Records are created with a RecordValidation and a RecordSigner. RecordValidation indicates under what conditions the record is considered valid, for example before a certain date (EOL) or between certain dates (TimeRange). RecordSigner adds verification data to a record, by signing it, eg with a private key, or with an x509 certificate.

Examples

Records created with the KeyRecordSigner have a BasePath() at /iprs/<key hash>

Creating an EOL record signed with a private key

pk := GenerateAPrivateKey()
vstore := CreateAValueStore()
dag := CreateADAGStore()
rs := NewRecordSystem(vstore, dag, rsv.NoCacheOpts)

// Get the CID of the target Node
p1, err := cid.Parse("/ipfs/QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN")
if err != nil {
	return err
}

// Create the record
eol := time.Now().Add(time.Hour)
validation := rec.NewEolRecordValidation(eol)
signer := rec.NewKeyRecordSigner(pk)
record, err := rec.NewRecord(validation, signer, p1.Bytes())
if err != nil {
	return err
}
iprsKey, err := signer.BasePath("myrec")
if err != nil {
	return err
}

// Publish the record
err = rs.Publish(ctx, iprsKey, record)

Creating a TimeRange record signed with a private key

// Create the record
var BeginningOfTime *time.Time // nil indicates the beginning of time (ie, no start date)
var EndOfTime *time.Time       // nil indicates the end of time (ie, no expiration)
start := BeginningOfTime
end := time.Now().Add(time.Hour)
validation := rec.NewRangeRecordValidation(start, end)
signer := rec.NewKeyRecordSigner(pk)
record, err := rec.NewRecord(validation, signer, p1.Bytes())
if err != nil {
	return err
}
iprsKey, err := signer.BasePath("myrec")
if err != nil {
	return err
}

// Publish the record
err = rs.Publish(ctx, iprsKey, record)

Records created with the CertRecordSigner have a BasePath() at /iprs/<ca cert key hash>. The CA Certificate can issue a child certificate that can be used to create a record under the CA Certificate's path. This provides a way to share IPRS path ownership between different users. For example Alice creates a CA Certificate and publishes a record at /iprs/<alice ca cert hash>/myrepo. She then issues a child certificate to Bob. Bob can now publish a new record to the same IPRS key.

Creating an EOL record signed with a CA certificate key

caCert, caPk := GenerateCACertificate()
childCert, childPk := GenerateChildCertificate(caCert, caPk)

// Value is CID of Alice's commit
p1, err := cid.Parse("/ipfs/ipfsHashOfAlicesCommit")

// Create the record with the CA certificate
validation := rec.NewEolRecordValidation(eol)
signer := rec.NewCertRecordSigner(caCert, caPk)
record, err := rec.NewRecord(validation, signer, p1.Bytes())
if err != nil {
	return err
}

// Publish the record
iprsKey, err := signer.BasePath("myrepo") // /iprs/<cert hash>/myrepo
if err != nil {
	return err
}
err = rs.Publish(ctx, iprsKey, record)
if err != nil {
	return err
}

// ...

// Create a record with the child certificate
// Value is CID of Bob's commit
p2, err := cid.Parse("/ipfs/ipfsHashOfBobsCommit")

validation := rec.NewEolRecordValidation(eol)
signer := rec.NewCertRecordSigner(childCert, childPk)
record2, err := rec.NewRecord(validation, signer, p2.Bytes())
if err != nil {
	return err
}

// Publish the record to the same IPRS path
// /iprs/<cert hash>/myrepo
err = rs.Publish(ctx, iprsKey, record2)

Resolving an IPRS path to its target Node

iprsPath := GetIprsPath()
nodeLink, path, err := rs.Resolve(ctx, iprsPath)
fmt.Printf("Link with CID %s and path %s", nodeLink.Cid, path)

Using Gx and Gx-go

This module is packaged with Gx. In order to use it in your own project it is recommended that you:

go get -u github.com/whyrusleeping/gx
go get -u github.com/whyrusleeping/gx-go
cd <your-project-repository>
gx init
gx import github.com/ipfs/go-iprs
gx install --global
gx-go --rewrite

Please check Gx and Gx-go documentation for more information.

License

MIT