Verify Signed Binaries

Walrus release binaries and Docker images are signed using Cosign with a GCP KMS key. Each binary has a corresponding .sig file containing its signature. Docker image signatures are stored in the registry.

Prerequisites

• Install Cosign
• Install the gcloud CLI (for downloading binaries)

Use the verification script

The easiest way to download and verify binaries is to use the provided script. See also the Storage Node Setup guide for standard binary downloads without verification.

# Download the script
curl -sSfL https://raw.githubusercontent.com/MystenLabs/walrus/main/scripts/download_and_verify_binary.sh \
  -o download_and_verify_binary.sh
chmod +x download_and_verify_binary.sh

# Download and verify a binary
./download_and_verify_binary.sh <ref> <binary_name>

The command takes 2 arguments:

• ref: A git reference (branch, tag, or commit SHA)
• binary_name: The full binary name with platform suffix

For example:

./download_and_verify_binary.sh v1.0.0 walrus-ubuntu-x86_64

This downloads the binary and signature, then verifies the signature using the public key.

Available platforms

Platform	Suffix
Linux x86_64	-ubuntu-x86_64
Linux ARM64	-ubuntu-aarch64
macOS x86_64	-macos-x86_64
macOS ARM64	-macos-arm64
Windows x86_64	-windows-x86_64.exe

Available binaries

Binary	Description
walrus	The Walrus CLI client
walrus-node	The Walrus storage node
walrus-upload-relay	The Walrus upload relay service

Verify manually

If you prefer to verify manually without the script, first download the signed binaries from Google Cloud Storage:

# Download the binary
gcloud storage cp gs://mysten-walrus-binaries/signed/<ref>/walrus-ubuntu-x86_64 ./walrus

# Download the signature
gcloud storage cp gs://mysten-walrus-binaries/signed/<ref>/walrus-ubuntu-x86_64.sig ./walrus.sig

Then verify them using the public key:

# Download the public key
curl -sSfL https://docs.walrus.site/walrus-signing.pub -o walrus-signing.pub

# Verify the binary
cosign verify-blob \
  --key walrus-signing.pub \
  --signature walrus.sig \
  --insecure-ignore-tlog \
  walrus

If successful, the output displays:

Verified OK

info

The --insecure-ignore-tlog flag is required because signatures are not uploaded to the Sigstore transparency log. Verification is still cryptographically secure using the signing key.

Verify using the GCP KMS key directly

If you have GCP access:

# Authenticate with GCP
gcloud auth application-default login

# Verify the binary
cosign verify-blob \
  --key gcpkms://projects/walrus-infra/locations/global/keyRings/walrus-signing/cryptoKeys/release-sign \
  --signature walrus.sig \
  --insecure-ignore-tlog \
  walrus

Verify Docker images

Signed Docker images are published to Docker Hub with the -signed suffix.

Available images

Image	Description
mysten/walrus-service	Walrus storage node service
mysten/walrus-upload-relay	Walrus upload relay service

Image tags

Each image is tagged in 2 ways:

• By commit SHA: mysten/walrus-service:FULL_SHA-signed
• By version: mysten/walrus-service:vVERSION-signed

Pull a signed image

# Pull by version
docker pull mysten/walrus-service:v1.0.0-signed

# Pull by commit SHA
docker pull mysten/walrus-service:a5a6dc7b12345678-signed

Verify a Docker image

# Download the public key
curl -sSfL https://docs.walrus.site/walrus-signing.pub -o walrus-signing.pub

# Verify the image
cosign verify --key walrus-signing.pub mysten/walrus-service:v1.0.0-signed

You can also verify using the GCP KMS key directly:

cosign verify \
  --key gcpkms://projects/walrus-infra/locations/global/keyRings/walrus-signing/cryptoKeys/release-sign \
  mysten/walrus-service:v1.0.0-signed

Verify the image digest matches

To ensure the image you pulled matches what was signed:

# Get the digest of your local image
docker inspect --format='{{index .RepoDigests 0}}' mysten/walrus-service:v1.0.0-signed

# Compare with the digest shown in the cosign verify output

Troubleshoot common errors

Permission denied when verifying

If you get a permission denied error when using the GCP KMS key directly, try one of the following:

• Authenticate with GCP by running gcloud auth application-default login.
• Use the public key method instead.

Signature verification failed

If verification fails:

1. Ensure you downloaded both the binary and signature for the same version.
2. Ensure the files were not corrupted during download.
3. Try re-downloading both files.

No matching signatures error for Docker images

If you see a no matching signatures error:

1. Ensure the image tag includes the -signed suffix.
2. Verify the commit SHA is correct.
3. Check that the image was actually signed.

Image not found

If the Docker image is not found:

1. Verify the commit SHA exists in the repository.
2. Check that the signed binaries workflow ran successfully for that commit.
3. Ensure you are using the correct image name.

Security considerations

The signing infrastructure has the following properties:

• The signing key is stored in GCP KMS and cannot be exported.
• Only authorized CI/CD workflows can sign binaries and images.
• Each binary is signed individually, not just the archive.
• Docker image signatures are stored in the registry alongside the image.