Code Signing

In Infisical, Code Signing lets you digitally sign software artifacts (JARs, binaries, container images, and more) while keeping private keys secure on the server. Instead of distributing signing keys to developer workstations or CI pipelines, signing operations are performed centrally through Infisical with full audit trails and approval controls.

How It Works

sequenceDiagram
    participant Tool as Signing Tool
    participant PKCS as PKCS#11 Module
    participant Infisical as Infisical

    Tool->>PKCS: Sign data
    PKCS->>Infisical: POST /signers/{id}/sign
    Infisical->>Infisical: Validate grant, sign data
    Infisical-->>PKCS: Signature
    PKCS-->>Tool: Signature

1. A Signer is created and bound to a certificate with the codeSigning extended key usage.
2. Optionally, a Signing Policy is attached to govern who can use the signer and under what conditions. Without a policy, authorized users and identities can sign immediately.
3. When a policy is configured, users or machine identities request signing access through the signing workflow. Once approved, the caller receives a grant that authorizes signing operations.
4. The signing tool (e.g., jarsigner) calls the Infisical API, either directly or through the PKCS#11 module, and the signature is computed server-side.
5. Every signing operation is recorded as an immutable audit entry on the signer.

Core Concepts

Signers

A signer is a named code-signer bound to a certificate. It represents a signing capability within a project. Private keys are stored securely on the Infisical server and never leave it. All cryptographic operations are performed server-side.

Signing Policies

Signing policies optionally define the rules that must be satisfied before signing can occur. Policies support constraints that can be combined:

• Max Window Duration: Limits how long a signing grant remains valid.
• Max Signings: Limits the total number of signing operations a grant allows.

Signing Operations

Every call to sign data, whether it succeeds, fails, or is denied, is recorded as a signing operation. This provides a complete audit trail of who signed what, when, and using which grant.

PKCS#11 Module

The Infisical PKCS#11 module implements the PKCS#11 v2.40 standard, allowing standard signing tools to use Infisical signers without code changes. The module supports RSA (PKCS#1 v1.5 and PSS) and ECDSA signing mechanisms.

Getting Started