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	./config/nuts.yaml	Nuts config file
cpuprofile		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.
didmethods	[web,nuts]	Comma-separated list of enabled DID methods (without did: prefix). It also controls the order in which DIDs are returned by APIs, and which DID is used for signing if the verifying party does not impose restrictions on the DID method used.
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	true	When set, insecure settings are forbidden.
url		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	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.
Auth
auth.authorizationendpoint.enabled	false	enables the v2 API's OAuth2 Authorization Endpoint, used by OpenID4VP and OpenID4VCI. This flag might be removed in a future version (or its default become 'true') as the use cases and implementation of OpenID4VP and OpenID4VCI mature.
Crypto
crypto.storage		Storage to use, 'fs' for file system (for development purposes), 'vaultkv' for HashiCorp Vault KV store, 'azure-keyvault' for Azure Key Vault, 'external' for an external backend (deprecated).
crypto.azurekv.hsm	false	Whether to store the key in a hardware security module (HSM). If true, the Azure Key Vault must be configured for HSM usage. Default: false
crypto.azurekv.timeout	10s	Timeout of client calls to Azure Key Vault, in Golang time.Duration string format (e.g. 10s).
crypto.azurekv.url		The URL of the Azure Key Vault.
crypto.azurekv.auth.type	default	Credential type to use when authenticating to the Azure Key Vault. Options: default, managed_identity (see https://github.com/Azure/azure-sdk-for-go/blob/main/sdk/azidentity/README.md for an explanation of the options).
crypto.vault.address		The Vault address. If set it overwrites the VAULT_ADDR env var.
crypto.vault.pathprefix	kv	The Vault path prefix.
crypto.vault.timeout	5s	Timeout of client calls to Vault, in Golang time.Duration string format (e.g. 1s).
crypto.vault.token		The Vault token. If set it overwrites the VAULT_TOKEN env var.
Discovery
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	[]	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
http.clientipheader	X-Forwarded-For	Case-sensitive HTTP Header that contains the client IP used for audit logs. For the X-Forwarded-For header only link-local, loopback, and private IPs are excluded. Switch to X-Real-IP or a custom header if you see your own proxy/infra in the logs.
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). When debug vebosity is set the authorization headers are also logged when the request is fully logged.
http.cache.maxbytes	10485760	HTTP client maximum size of the response cache in bytes. If 0, the HTTP client does not cache responses.
http.internal.address	127.0.0.1:8081	Address and port the server will be listening to for internal-facing endpoints.
http.internal.auth.audience		Expected audience for JWT tokens (default: hostname)
http.internal.auth.authorizedkeyspath		Path to an authorized_keys file for trusted JWT signers
http.internal.auth.type		Whether to enable authentication for /internal endpoints, specify 'token_v2' for bearer token mode or 'token' for legacy bearer token mode.
http.public.address	:8080	Address and port the server will be listening to for public-facing endpoints.
JSONLD
jsonld.contexts.localmapping	[https://nuts.nl/credentials/2024=assets/contexts/nuts-2024.ldjson,https://nuts.nl/credentials/v1=assets/contexts/nuts.ldjson,https://schema.org=assets/contexts/schema-org-v13.ldjson,https://w3c-ccg.github.io/lds-jws2020/contexts/lds-jws2020-v1.json=assets/contexts/lds-jws2020-v1.ldjson,https://w3id.org/vc/status-list/2021/v1=assets/contexts/w3c-statuslist2021.ldjson,https://www.w3.org/2018/credentials/v1=assets/contexts/w3c-credentials-v1.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	[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
pki.maxupdatefailhours	4	Maximum number of hours that a denylist update can fail
pki.softfail	true	Do not reject certificates if their revocation status cannot be established when softfail is true
Storage
storage.session.memcached.address	[]	List of Memcached server addresses. These can be a simple 'host:port' or a Memcached connection URL with scheme, auth and other options.
storage.session.redis.address		Redis session database server address. This can be a simple 'host:port' or a Redis connection URL with scheme, auth and other options. If not set it, defaults to an in-memory database.
storage.session.redis.database		Redis session database name, which is used as prefix every key. Can be used to have multiple instances use the same Redis instance.
storage.session.redis.password		Redis session database password. If set, it overrides the username in the connection URL.
storage.session.redis.username		Redis session database username. If set, it overrides the username in the connection URL.
storage.session.redis.tls.truststorefile		PEM file containing the trusted CA certificate(s) for authenticating remote Redis session servers. Can only be used when connecting over TLS (use 'rediss://' as scheme in address).
storage.sql.connection		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').
policy
policy.directory	./config/policy	Directory to read policy files from. Policy files are JSON files that contain a scope to PresentationDefinition mapping.

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		PEM file containing the certificate for the gRPC server (also used as client certificate). Required in strict mode.
tls.certheader		Name of the HTTP header that will contain the client certificate when TLS is offloaded for gRPC.
tls.certkeyfile		PEM file containing the private key of the gRPC server certificate. Required in strict mode.
tls.offload		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	./config/ssl/truststore.pem	PEM file containing the trusted CA certificates for authenticating remote gRPC servers. Required in strict mode.
Auth
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	pbdf	IRMA schemeManager to use for attributes. Can be either 'pbdf' or 'irma-demo'.
auth.irma.cors.origin	[]	sets the allowed CORS origins for the IRMA server
Events
events.nats.hostname	0.0.0.0	Hostname for the NATS server
events.nats.port	4222	Port where the NATS server listens on
events.nats.storagedir		Directory where file-backed streams are stored in the NATS server
events.nats.timeout	30	Timeout for NATS server operations
GoldenHammer
goldenhammer.enabled	true	Whether to enable automatically fixing DID documents with the required endpoints.
goldenhammer.interval	10m0s	The interval in which to check for DID documents to fix.
Network
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	24h0m0s	Maximum between outbound connections attempts to unresponsive nodes (in Golang duration format, e.g. '1h', '30m').
network.nodedid		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	5000	Interval (in milliseconds) that specifies how often the node should gossip its new hashes to other nodes.
Storage
storage.bbolt.backup.directory		Target directory for BBolt database backups.
storage.bbolt.backup.interval	0s	Interval, formatted as Golang duration (e.g. 10m, 1h) at which BBolt database backups will be performed.
storage.redis.address		Redis database server address. This can be a simple 'host:port' or a Redis connection URL with scheme, auth and other options.
storage.redis.database		Redis database name, which is used as prefix every key. Can be used to have multiple instances use the same Redis instance.
storage.redis.password		Redis database password. If set, it overrides the username in the connection URL.
storage.redis.username		Redis database username. If set, it overrides the username in the connection URL.
storage.redis.sentinel.master		Name of the Redis Sentinel master. Setting this property enables Redis Sentinel.
storage.redis.sentinel.nodes	[]	Addresses of the Redis Sentinels to connect to initially. Setting this property enables Redis Sentinel.
storage.redis.sentinel.password		Password for authenticating to Redis Sentinels.
storage.redis.sentinel.username		Username for authenticating to Redis Sentinels.
storage.redis.tls.truststorefile		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).
VCR
vcr.openid4vci.definitionsdir		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 and data requires some serious consideration. For this reason the crypto.storage backend and the storage.sql.connection connection string 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 :ref:`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, 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.