nuts-node

Open-source implementation of did:web, OpenID4VC, PEX, private key management and related logic. It enables secure and trusted data exchange between organizations. It contains all the necessary components for secure discovery and authorization.

See the documentation for how to set up, integrate and use the Nuts node.

Development

or higher is required.

Building

Just use go build.

ES256 Koblitz support

To enable ES256K (Koblitz) support, you need to build with the jwx_es256k tag:

go build -tags jwx_es256k

Building for exotic environments

You can build and run the Nuts node on more exotic environments, e.g. Raspberry Pis:

• 32-bit ARMv6 (Raspberry Pi Zero): env GOOS=linux GOARCH=arm GOARM=6 go build

Running tests

Tests can be run by executing

go test ./...

Code Generation

Code generation is used for generating mocks, OpenAPI client- and servers, and gRPC services. Make sure that GOPATH/bin is available on PATH and that the dependencies are installed

Install protoc:

MacOS: brew install protobuf
Linux: apt install -y protobuf-compiler

Install Go tools:

make install-tools

Generating code:

To regenerate all code run the run-generators target from the makefile or use one of the following for a specific group

Group	Command
Mocks	make gen-mocks
OpenApi	make gen-api
Protobuf + gRCP	make gen-protobuf
All	make run-generators

README

The readme is auto-generated from a template and uses the documentation to fill in the blanks.

make gen-readme

Documentation

The documentation can be build by running the following command from the /docs directory:

make html

Configuration

The Nuts node can be configured using a YAML configuration file, environment variables and commandline params.

The parameters follow the following convention: $ nuts --parameter X is equal to $ NUTS_PARAMETER=X nuts is equal to parameter: X in a yaml file.

Or for this piece of yaml

nested:
    parameter: X

is equal to $ nuts --nested.parameter X is equal to $ NUTS_NESTED_PARAMETER=X nuts

Config parameters for engines are prepended by the engine.ConfigKey by default (configurable):

engine:
    nested:
        parameter: X

is equal to $ nuts --engine.nested.parameter X is equal to $ NUTS_ENGINE_NESTED_PARAMETER=X nuts

While most options are a single value, some are represented as a list (indicated with the square brackets in the table below). To provide multiple values through flags or environment variables you can separate them with a comma (var1,var2). If you need to provide an actual value with a comma, you can escape it with a backslash (\,) to avoid it having split into multiple values.

Ordering

Command line parameters have the highest priority, then environment variables, then parameters from the configfile and lastly defaults. The location of the configfile is determined by the environment variable NUTS_CONFIGFILE or the commandline parameter --configfile. If both are missing the default location ./nuts.yaml is used. :

CLI > ENV > Config File > Defaults

Server options

The following options can be configured on the server:

Server Options

Key	Default	Description
configfile cpuprofile	./config/nuts.yaml	Nuts config file When set, a CPU profile is written to the given path. Ignored when strictmode is set.
datadir	./data	Directory where the node stores its files.
internalratelimiter	true	When set, expensive internal calls are rate-limited to protect the network. Always enabled in strict mode.
loggerformat	text	Log format (text, json)
strictmode url	true	When set, insecure settings are forbidden. Public facing URL of the server (required). Must be HTTPS when strictmode is set.
verbosity	info	Log level (trace, debug, info, warn, error)
httpclient.timeout Crypto crypto.storage crypto.external.address	30s	Request time-out for HTTP clients, such as '10s'. Refer to Golang's 'time.Duration' syntax for a more elaborate description of the syntax. Storage to use, 'external' for an external backend (experimental), 'fs' for file system (for development purposes), 'vaultkv' for Vault KV store (recommended, will be replaced by external backend in future). Address of the external storage service.
crypto.external.timeout crypto.vault.address	100ms	Time-out when invoking the external storage backend, in Golang time.Duration string format (e.g. 1s). The Vault address. If set it overwrites the VAULT_ADDR env var.
crypto.vault.pathprefix	kv	The Vault path prefix.
crypto.vault.timeout crypto.vault.token Discovery	5s	Timeout of client calls to Vault, in Golang time.Duration string format (e.g. 1s). The Vault token. If set it overwrites the VAULT_TOKEN env var.
discovery.client.refresh_interval	10m0s	Interval at which the client synchronizes with the Discovery Server; refreshing Verifiable Presentations of local DIDs and loading changes, updating the local copy. It only will actually refresh registrations of local DIDs that about to expire (less than 1/4th of their lifetime left). Specified as Golang duration (e.g. 1m, 1h30m).
discovery.definitions.directory	./config/discovery	Directory to load Discovery Service Definitions from. If not set, the discovery service will be disabled. If the directory contains JSON files that can't be parsed as service definition, the node will fail to start.
discovery.server.ids HTTP	[]	IDs of the Discovery Service for which to act as server. If an ID does not map to a loaded service definition, the node will fail to start.
http.log	metadata	What to log about HTTP requests. Options are 'nothing', 'metadata' (log request method, URI, IP and response code), and 'metadata-and-body' (log the request and response body, in addition to the metadata).
http.internal.address http.internal.auth.audience http.internal.auth.authorizedkeyspath http.internal.auth.type	127.0.0.1:8081	Address and port the server will be listening to for internal-facing endpoints. Expected audience for JWT tokens (default: hostname) Path to an authorized_keys file for trusted JWT signers Whether to enable authentication for /internal endpoints, specify 'token_v2' for bearer token mode or 'token' for legacy bearer token mode.
http.public.address JSONLD	:8080	Address and port the server will be listening to for public-facing endpoints.
jsonld.contexts.localmapping	[https://nuts.nl/credentials/v1=assets/contexts/nuts.ldjson,https://www.w3.org/2018/credentials/v1=assets/contexts/w3c-credentials-v1.ldjson,https://w3id.org/vc/status-list/2021/v1=assets/contexts/w3c-statuslist2021.ldjson,https://w3c-ccg.github.io/lds-jws2020/contexts/lds-jws2020-v1.json=assets/contexts/lds-jws2020-v1.ldjson,https://schema.org=assets/contexts/schema-org-v13.ldjson]	This setting allows mapping external URLs to local files for e.g. preventing external dependencies. These mappings have precedence over those in remoteallowlist.
jsonld.contexts.remoteallowlist PKI	[https://schema.org,https://www.w3.org/2018/credentials/v1,https://w3c-ccg.github.io/lds-jws2020/contexts/lds-jws2020-v1.json,https://w3id.org/vc/status-list/2021/v1]	In strict mode, fetching external JSON-LD contexts is not allowed except for context-URLs listed here.
pki.maxupdatefailhours	4	Maximum number of hours that a denylist update can fail
pki.softfail Storage storage.sql.connection policy policy.address	true	Do not reject certificates if their revocation status cannot be established when softfail is true Connection string for the SQL database. If not set it, defaults to a SQLite database stored inside the configured data directory. Note: using SQLite is not recommended in production environments. If using SQLite anyways, remember to enable foreign keys ('_foreign_keys=on') and the write-ahead-log ('_journal_mode=WAL'). The address of a remote policy server. Mutual exclusive with policy.directory.
policy.directory	./config/policy	Directory to read policy files from. Policy files are JSON files that contain a scope to PresentationDefinition mapping. Mutual exclusive with policy.address.

Options specific for did:nuts/gRPC

The following table contains additional (deprecated) options that are relevant for use cases that use did:nuts DIDs and/or the gRPC network. If your use case does not use these features, you can ignore this table.

did:nuts/gRPC Server Options

Key	Default	Description
tls.certfile tls.certheader tls.certkeyfile tls.offload		PEM file containing the certificate for the gRPC server (also used as client certificate). Required in strict mode. Name of the HTTP header that will contain the client certificate when TLS is offloaded for gRPC. PEM file containing the private key of the gRPC server certificate. Required in strict mode. Whether to enable TLS offloading for incoming gRPC connections. Enable by setting it to 'incoming'. If enabled 'tls.certheader' must be configured as well.
tls.truststorefile Auth	./config/ssl/truststore.pem	PEM file containing the trusted CA certificates for authenticating remote gRPC servers. Required in strict mode.
auth.accesstokenlifespan	60	defines how long (in seconds) an access token is valid. Uses default in strict mode.
auth.clockskew	5000	allowed JWT Clock skew in milliseconds
auth.contractvalidators	[irma,dummy,employeeid]	sets the different contract validators to use
auth.irma.autoupdateschemas	true	set if you want automatically update the IRMA schemas every 60 minutes.
auth.irma.schememanager Events	pbdf	IRMA schemeManager to use for attributes. Can be either 'pbdf' or 'irma-demo'.
events.nats.hostname	0.0.0.0	Hostname for the NATS server
events.nats.port events.nats.storagedir	4222	Port where the NATS server listens on Directory where file-backed streams are stored in the NATS server
events.nats.timeout GoldenHammer	30	Timeout for NATS server operations
goldenhammer.enabled	true	Whether to enable automatically fixing DID documents with the required endpoints.
goldenhammer.interval Network	10m0s	The interval in which to check for DID documents to fix.
network.bootstrapnodes	[]	List of bootstrap nodes ('<host>:<port>') which the node initially connect to.
network.connectiontimeout	5000	Timeout before an outbound connection attempt times out (in milliseconds).
network.enablediscovery	true	Whether to enable automatic connecting to other nodes.
network.grpcaddr	:5555	Local address for gRPC to listen on. If empty the gRPC server won't be started and other nodes will not be able to connect to this node (outbound connections can still be made).
network.maxbackoff network.nodedid	24h0m0s	Maximum between outbound connections attempts to unresponsive nodes (in Golang duration format, e.g. '1h', '30m'). Specifies the DID of the party that operates this node. It is used to identify the node on the network. If the DID document does not exist of is deactivated, the node will not start.
network.protocols	[]	Specifies the list of network protocols to enable on the server. They are specified by version (1, 2). If not set, all protocols are enabled.
network.v2.diagnosticsinterval	5000	Interval (in milliseconds) that specifies how often the node should broadcast its diagnostic information to other nodes (specify 0 to disable).
network.v2.gossipinterval Storage storage.bbolt.backup.directory	5000	Interval (in milliseconds) that specifies how often the node should gossip its new hashes to other nodes. Target directory for BBolt database backups.
storage.bbolt.backup.interval storage.redis.address storage.redis.database storage.redis.password storage.redis.username storage.redis.sentinel.master	0s	Interval, formatted as Golang duration (e.g. 10m, 1h) at which BBolt database backups will be performed. Redis database server address. This can be a simple 'host:port' or a Redis connection URL with scheme, auth and other options. Redis database name, which is used as prefix every key. Can be used to have multiple instances use the same Redis instance. Redis database password. If set, it overrides the username in the connection URL. Redis database username. If set, it overrides the username in the connection URL. Name of the Redis Sentinel master. Setting this property enables Redis Sentinel.
storage.redis.sentinel.nodes storage.redis.sentinel.password storage.redis.sentinel.username storage.redis.tls.truststorefile storage.session.redis.address storage.session.redis.database storage.session.redis.password storage.session.redis.username storage.session.redis.sentinel.master	[]	Addresses of the Redis Sentinels to connect to initially. Setting this property enables Redis Sentinel. Password for authenticating to Redis Sentinels. Username for authenticating to Redis Sentinels. PEM file containing the trusted CA certificate(s) for authenticating remote Redis servers. Can only be used when connecting over TLS (use 'rediss://' as scheme in address). Redis database server address. This can be a simple 'host:port' or a Redis connection URL with scheme, auth and other options. Redis database name, which is used as prefix every key. Can be used to have multiple instances use the same Redis instance. Redis database password. If set, it overrides the username in the connection URL. Redis database username. If set, it overrides the username in the connection URL. Name of the Redis Sentinel master. Setting this property enables Redis Sentinel.
storage.session.redis.sentinel.nodes	[]	Addresses of the Redis Sentinels to connect to initially. Setting this property enables Redis Sentinel.
storage.session.redis.sentinel.passwor	d	Password for authenticating to Redis Sentinels.
storage.session.redis.sentinel.usernam	e	Username for authenticating to Redis Sentinels.
storage.session.redis.tls.truststorefi VCR vcr.openid4vci.definitionsdir	le	PEM file containing the trusted CA certificate(s) for authenticating remote Redis servers. Can only be used when connecting over TLS (use 'rediss://' as scheme in address). Directory with the additional credential definitions the node could issue (experimental, may change without notice).
vcr.openid4vci.enabled	true	Enable issuing and receiving credentials over OpenID4VCI.
vcr.openid4vci.timeout	30s	Time-out for OpenID4VCI HTTP client operations.

This table is automatically generated using the configuration flags in the core and engines. When they're changed the options table must be regenerated using the Makefile:

$ make docs

Secrets

All options ending with token or password are considered secrets and can only be set through environment variables or the config file.

Strict mode

Several of the server options above allow the node to be configured in a way that is unsafe for production environments, but are convenient for testing or development. The node can be configured to run in strict mode (default) to prevent any insecure configurations. Below is a summary of the impact strictmode=true has on the node and its configuration.

Save storage of any private key material requires some serious consideration. For this reason the crypto.storage backend must explicitly be set.

Private transactions can only be exchanged over authenticated nodes. Therefore is requires TLS to be configured through tls.{certfile,certkeyfile,truststore}. To verify that authentication is correctly configured on your node, check the network.auth_config status on the /health endpoint. See Monitoring <nuts-node-monitoring> for more details.

The incorporated IRMA server is automatically changed to production mode. In fact, running in strict mode is the only way to enable IRMA's production mode. In addition, it requires auth.irma.schememanager=pbdf.

As a general safety precaution auth.contractvalidators ignores the dummy option if configured, requesting an access token from another node on /n2n/auth/v1/accesstoken does not return any error details, auth.accesstokenlifespan is always 60 seconds, http.default.cors.origin does not allow a wildcard (*), json-ld context can only be downloaded from trusted domains configured in jsonld.contexts.remoteallowlist, and the internalratelimiter is always on.

Interacting with remote Nuts nodes requires HTTPS: it will refuse to connect to plain HTTP endpoints when in strict mode.