ToolUp.ArtefactSigning.AwsKms 0.39.2

ToolUp.ArtefactSigning.AwsKms

AWS KMS-backed IArtefactSigner for ToolUp.ArtefactSigning (Phase 40 / 22a). Signs artefacts with an AWS KMS asymmetric ECDSA P-256 (ECC_NIST_P256) key — the private key never enters process memory. The signer hashes the JWS signing input locally (SHA-256) and asks KMS to sign the digest, then converts the DER signature KMS returns into the raw r‖s shape JWS ES256 requires. The detached JWS is byte-identical to the in-process DefaultArtefactSigner output, so the shipped DefaultArtefactVerifier (or any JWS verifier holding the public key) validates it.

GP 1 — the AWS SDK dependency is isolated to this companion; it never reaches the ToolUp.ArtefactSigning substrate. Server-only companion.

Quick start

open Amazon.KeyManagementService
open ToolUp.ArtefactSigning.AwsKms

let kms = new AmazonKeyManagementServiceClient() // region + creds from the env
let signer = AwsKmsArtefactSigner.create kms "arn:aws:kms:eu-west-2:...:key/<asymmetric-ecc-key>"

let! result = signer.Sign artefactBytes        // -> Ok ArtefactSignature
let! pubKey = signer.VerifyKey ()              // PEM + JWK for the verification endpoint

The produced ArtefactSignature verifies with the in-process DefaultArtefactVerifier (the public key is served from KMS via GetPublicKey; the JWS shape is identical).

ECDSA P-256 only

AWS KMS asymmetric signing offers RSA + ECC (P-256/384/521) + SM2 — not Ed25519. The Phase 40 EdDSA flavour stays in-process (DefaultArtefactSigner); this companion covers ES256, the JWS shape compliance auditors expect for non-repudiation. The KMS key must be created with KeySpec = ECC_NIST_P256 and KeyUsage = SIGN_VERIFY.

Verification

The signer requires a live KMS asymmetric key (no offline fake — KMS has no local emulator and IAmazonKeyManagementService is not practically mockable). Mirrors the env-gated live-arm convention of the AWS KMS encryption resolver / AIProviders.Tests. Verify against a real key:

1. Create an asymmetric ECC_NIST_P256 / SIGN_VERIFY KMS key; grant the deployment role kms:Sign + kms:GetPublicKey.
2. Sign an artefact → verify the returned ArtefactSignature with DefaultArtefactVerifier (resolving the public key from VerifyKey).
3. Tamper the artefact → verification fails (VerificationError.Tampered).

The pure DER→P1363 conversion + JWS-assembly helpers (JwsBuilder.derEcdsaToP1363 / assembleDetachedJws) are unit-tested offline in ToolUp.ArtefactSigning.Tests.

License

Apache-2.0.