Quickstart: SCITT Statements (Preview)

How to push a collection of Statements using SCITT APIs

The SCITT API is currently in preview and subject to change

The Supply Chain Integrity, Transparency and Trust (SCITT) initiative is a set of IETF standards for managing the compliance and auditability of goods and services across end-to-end supply chains. SCITT supports the ongoing verification of goods and services where the authenticity of entities, evidence, policy, and artifacts can be assured and the actions of entities can be guaranteed to be authorized, non-repudiable, immutable, and auditable.

To assure insights to supply chain artifacts are current, the SCITT APIs provide a correlation of statements, allowing verifiers to view a full history of statements. This includes previously registered statements, and newly registered statements providing the most up to date insights.

This quickstart will:

1. create, or use an existing a key to sign a collection of statements about an artifact
2. create and register a statement for an artifact
3. query a collection of statements about the artifact

Prerequisites#

• A DataTrails subscription with a Token for API access
• DataTrails sample code
• Python to run the samples
• Environment Configuration

DataTrails Sample Code#

The Quickstart uses existing samples and scripts to focus on the SCITT APIs.

Clone the DataTrails SCITT Examples repository to copy those files to your environment.

git clone https://github.com/datatrails/datatrails-scitt-samples.git && \
cd datatrails-scitt-samples

Environment Configuration#

1. Create a Python Virtual Environment for the sample scripts and install the dependencies

   python -m  venv venv && \
   source venv/bin/activate && \
   pip install --upgrade pip && \
   pip install -r requirements.txt
   

2. To ease copying and pasting commands, update any variables to fit your environment

   # your identity
   ISSUER="sample.synsation.io"
   
   # signing key to sign the SCITT Statements
   SIGNING_KEY="my-signing-key.pem"
   
   # File representing the signed statement to be registered
   SIGNED_STATEMENT_FILE="signed-statement.cbor"
   
   # File representing the transparent statement, which includes the signed statement and the registration receipt
   TRANSPARENT_STATEMENT_FILE="transparent-statement.cbor"
   
   # Subject is a property used to correlate a collection of statements about an artifact
   SUBJECT="my-product-id"
   

Create a Signing Key#

If you already have a signing key, skip ahead to Generating a Payload

For the Quickstart, create a testing key which DataTrails will cryptographically validate upon registration

openssl ecparam -name prime256v1 -genkey -out $SIGNING_KEY

Generate a Payload#

Create any payload you wish to register on DataTrails.

cat > payload.json <<EOF
{
    "author": "fred",
    "title": "my biography",
    "reviews": "mixed"
}
EOF

Create a COSE Signed Statement#

Create a COSE Signed Statement, hashing the content of the payload.json file. The payload may already be stored in another storage/package manager, which can be referenced with the --location-hint parameter.

python scitt/create_hashed_signed_statement.py \
  --content-type "application/json" \
  --issuer $ISSUER \
  --payload-file payload.json \
  --payload-location "https://storage.example/$SUBJECT" \
  --signing-key-file $SIGNING_KEY \
  --subject $SUBJECT \
  --output-file $SIGNED_STATEMENT_FILE

Register the SCITT Statement on DataTrails#

1. Submit the Signed Statement to DataTrails, using the credentials in the DATATRAILS_CLIENT_ID and DATATRAILS_CLIENT_SECRET.

   python scitt/register_signed_statement.py \
     --signed-statement-file signed-statement.cbor \
     --output-file $TRANSPARENT_STATEMENT_FILE \
     --log-level INFO
   

2. View the Transparent Statement, as a result of registering the Signed Statement

   python scitt/dump_cbor.py \
     --input signed-statement.cbor
   

Retrieve Statements for the Artifact#

The power of SCITT is the ability to retrieve the history of statements made for a given artifact. By querying the series of statements, consumers can verify who did what and when for a given artifact.

1. Query DataTrails for the collection of statements

   curl -H @$HOME/.datatrails/bearer-token.txt \
     https://app.datatrails.ai/archivist/v2/publicassets/-/events?event_attributes.subject=$SUBJECT | jq
   

Coming soon: Filter on specific content types, such as what SBOMs have been registered, or which issuers have made statements.

Verify Receipt Integrity#

To verify the signature of the receipt

python scitt/verify_receipt_signature.py \
  --transparent-statement-file $TRANSPARENT_STATEMENT_FILE

Summary#

The quickstart created a collection of statements for a given artifact. Over time, as new information is available, authors can publish new statements which verifiers and consumers can benefit from, making decisions specific to their environment.

There are no limits to the types of additional statements that may be registered, which may include new vulnerability information, notifications of new versions, end of life (EOL) notifications, or more. By using the content-type parameter, verifiers can filter to specific types, filter statements by the issuer, or other headers & metadata.

For more information:

• SCITT.io