Unwrapped and base64-decoded from the Sigstore Bundles and DSSE Envelopes, NPM V1 attestations are actually two parts: SLSA's build provenance and NPM's publish attestations. slsa-verifier will verify the envelopes and bundles around both attestations with the attestations file.
example build attestation
$ curl -Ss $(npm view [email protected] --json | jq -r '.dist.attestations.url') | jq '.attestations[1].bundle.dsseEnvelope.payload' -r | base64 -d | jq
{
"_type": "https://in-toto.io/Statement/v1",
"subject": [
{
"name": "pkg:npm/[email protected]",
"digest": {
"sha512": "8d9d7972f676516c75014aa074e11ae604d98f0b64ec6725a61e2838ff3dab162118fa71433fb31e1550d30bd0dec9d086ce032b94457b583900c507acf39c40"
}
}
],
"predicateType": "https://slsa.dev/provenance/v1",
"predicate": {
"buildDefinition": {
"buildType": "https://slsa-framework.github.io/github-actions-buildtypes/workflow/v1",
"externalParameters": {
"workflow": {
"ref": "refs/tags/v1.0.1",
"repository": "https://github.com/ramonpetgrave64/gundam-visor",
"path": ".github/workflows/npm-publish.yml"
}
},
"internalParameters": {
"github": {
"event_name": "release",
"repository_id": "810002373",
"repository_owner_id": "32398091"
}
},
"resolvedDependencies": [
{
"uri": "git+https://github.com/ramonpetgrave64/gundam-visor@refs/tags/v1.0.1",
"digest": {
"gitCommit": "599500821344b070902a7a5666064bfdaba715df"
}
}
]
},
"runDetails": {
"builder": {
"id": "https://github.com/actions/runner/github-hosted"
},
"metadata": {
"invocationId": "https://github.com/ramonpetgrave64/gundam-visor/actions/runs/9358004112/attempts/1"
}
}
}
}
exmaple publish attestation
$ curl -Ss $(npm view [email protected] --json | jq -r '.dist.attestations.url') | jq '.attestations[0].bundle.dsseEnvelope.payload' -r | base64 -d | jq
{
"_type": "https://in-toto.io/Statement/v0.1",
"subject": [
{
"name": "pkg:npm/[email protected]",
"digest": {
"sha512": "8d9d7972f676516c75014aa074e11ae604d98f0b64ec6725a61e2838ff3dab162118fa71433fb31e1550d30bd0dec9d086ce032b94457b583900c507acf39c40"
}
}
],
"predicateType": "https://github.com/npm/attestation/tree/main/specs/publish/v0.1",
"predicate": {
"name": "gundam-visor",
"version": "1.0.1",
"registry": "https://registry.npmjs.org"
}
}