feat(lab8): cosign sign + SBOM/provenance attestations + blob signing

.gitignore

@@ -16,7 +16,6 @@ labs/lab7/results/
 labs/lab8/results/
 labs/lab9/falco/logs/
 labs/lab10/work/dd/
-labs/lab10/imports/import-*.json
 labs/lab11/logs/
 labs/lab11/reverse-proxy/certs/
 labs/lab12/results/

.pre-commit-config.yaml

@@ -0,0 +1,11 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.5.0
+    hooks:
+      - id: detect-private-key
+      - id: check-added-large-files
+
+  - repo: https://github.com/gitleaks/gitleaks
+    rev: v8.30.1
+    hooks:
+      - id: gitleaks

labs/lab8/keys/cosign.pub

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+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE9+BnCtLaUoyCaWsvQ58yj+tbMY0p
+s7IKbCA1f+KzYb0+T+QoE0biBGg1B99aOkOM5V9ovf9FSA8Uhkd3M4iDMQ==
+-----END PUBLIC KEY-----

submissions/lab8.md

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+# Lab 8 — Submission
+## Task 1: Sign + Tamper Demo
+### Registry + image push
+- Registry container: `lab8-registry` running on `localhost:5000`
+- Image pushed: `localhost:5000/juice-shop:v20.0.0`
+- Image digest: `localhost:5000/juice-shop@sha256:8c76bce948965bcb2ad33c24a659d58f307d679ff48ec253a3d29138329f3c0d`
+### Signing
+- Output of `cosign sign` (success line):
+Pushing signature to: localhost:5000/juice-shop
+
+### Verification (PASSED)
+Output of `cosign verify` on original digest:
+```json
+[{"critical":{"identity":{"docker-reference":"localhost:5000/juice-shop"},"image":{"docker-manifest-digest":"sha256:8c76bce948965bcb2ad33c24a659d58f307d679ff48ec253a3d29138329f3c0d"},"type":"cosign container image signature"},"optional":{"Bundle":{"SignedEntryTimestamp":"MEYCIQDSJIhyvWHHFPtZSWbR/CRaoNlpVavwaJV28CNbztaOgQIhAKp6nelSUcZvFVcRywXq+k4pbEkcyQdXHGQdUSSfvy7c","Payload":{"body":"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","integratedTime":1783109783,"logIndex":2063967325,"logID":"c0d23d6ad406973f9559f3ba2d1ca01f84147d8ffc5b8445c224f98b9591801d"}}}}]
+
+```
+### Tamper Demo (FAILED — correctly)
+Output of cosign verify on tampered digest:
+```
+WARNING: Skipping tlog verification is an insecure practice that lacks of transparency and auditability verification for the signature.
+Error: no signatures found
+main.go:69: error during command execution: no signatures found
+```
+### Sanity — original still verifies
+```
+Verification for localhost:5000/juice-shop@sha256:8c76bce948965bcb2ad33c24a659d58f307d679ff48ec253a3d29138329f3c0d --
+The following checks were performed on each of these signatures:
+  - The cosign claims were validated
+  - The signatures were verified against the specified public key
+Why digest binding matters (Lecture 8 slide 6)
+Cosign binds the signature to the immutable image digest (SHA-256 of the image bytes), not to the human-readable tag. In the tamper demo, Alpine was re-tagged as juice-shop:v20.0.0-tampered, which produced a completely different digest (sha256:6c2a9711...) with no matching signature. If Cosign had signed only the tag :v20.0.0, an attacker could push malicious content under the same tag name and verification would still appear to pass — digest binding prevents this tag-mutation attack because the signature is cryptographically tied to the exact byte stream that was signed.
+```
+
+### Why digest binding matters (Lecture 8 slide 6)
+Cosign binds the signature to the immutable image digest (SHA-256 of the image bytes), not to the human-readable tag. In the tamper demo, Alpine was re-tagged as juice-shop:v20.0.0-tampered, which produced a completely different digest (sha256:6c2a9711...) with no matching signature. If Cosign had signed only the tag :v20.0.0, an attacker could push malicious content under the same tag name and verification would still appear to pass — digest binding prevents this tag-mutation attack because the signature is cryptographically tied to the exact byte stream that was signed.
+
+
+## Task 2: SBOM + Provenance Attestations
+### SBOM attestation
+- Attached: yes (`cosign attest --type cyclonedx` exit 0)
+- Verify-attestation output (first 30 lines of decoded payload):
+```json
+Verification for localhost:5000/juice-shop@sha256:8c76bce948965bcb2ad33c24a659d58f307d679ff48ec253a3d29138329f3c0d --
+The following checks were performed on each of these signatures:
+  - The cosign claims were validated
+  - The signatures were verified against the specified public key
+{
+  "_type": "https://in-toto.io/Statement/v0.1",
+  "predicateType": "https://cyclonedx.org/bom",
+  "subject": [
+    {
+      "name": "localhost:5000/juice-shop",
+      "digest": {
+        "sha256": "8c76bce948965bcb2ad33c24a659d58f307d679ff48ec253a3d29138329f3c0d"
+      }
+    }
+  ],
+  "predicate": {
+    "$schema": "http://cyclonedx.org/schema/bom-1.6.schema.json",
+    "bomFormat": "CycloneDX",
+    "components": [
+      {
+        "author": "Benjamin Byholm <bbyholm@abo.fi> (https://github.com/kkoopa/), Mathias Küsel (https://github.com/mathiask88/)",
+        "bom-ref": "pkg:npm/1to2@1.0.0?package-id=3cea2309a653e6ed",
+        "cpe": "cpe:2.3:a:nodejs:1to2:1.0.0:*:*:*:*:*:*:*",
+        "description": "NAN 1 -> 2 Migration Script",
+        "externalReferences": [
+          {
+            "type": "distribution",
+            "url": "git://github.com/nodejs/nan.git"
+          }
+        ],
+        "licenses": [
+          {
+            "license": {
+              "id": "MIT"
+```
+- Component count matches Lab 4 source: yes
+- diff between Lab 4 SBOM and extracted-from-attestation SBOM: `` (empty diff = success)
+### Provenance attestation
+- Attached: yes
+- Builder ID in predicate: https://localhost/lab8-student
+- buildType in predicate: https://example.com/lab8/local-build
+### What this gives a Lab 9 verifier (2-3 sentences)
+A signed image alone only proves who built/published it — it does not tell you what is inside. A signed image with a CycloneDX SBOM attestation lets an admission controller (e.g. Kyverno verify-images) require both a trusted signature AND a verifiable component list at deploy time. When the next Log4Shell hits, the "signed but no SBOM" image forces manual forensics to find affected libraries; the "signed with SBOM" image lets you query the attestation immediately for log4j coordinates and block or quarantine deployments before pods start.
+
+
+## Bonus: Blob Signing 
+### Sign + verify
+- Signed: `my-tool.tar.gz` + `my-tool.tar.gz.bundle`
+- Verify-blob success output:
+Verified OK
+
+### Tamper test failed (correctly)
+```
+WARNING: Skipping tlog verification is an insecure practice that lacks of transparency and auditability verification for the blob. Error: invalid signature when validating ASN.1 encoded signature main.go:74: error during command execution: invalid signature when validating ASN.1 encoded signature
+```
+
+### Codecov 2021 mitigation (2-3 sentences)
+```
+Codecov's bash uploader was distributed via `curl | bash` without signature verification, allowing a compromised script to run on CI machines. If consumers had run `cosign verify-blob --key cosign.pub --bundle install.sh.bundle install.sh` before executing the script, the modified bytes would have failed verification (`invalid signature`) and the pipeline would have stopped instead of running malicious code. This is exactly the `cosign verify-blob` API from Lecture 8 slide 14 — signing release artifacts at build time and verifying before execution closes the `curl | bash` trust gap.
+```