From a5df2854a3ef16f67ce0fd3cf48ced0f4fe1ca31 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 03:33:50 +0000
Subject: [PATCH 01/24] Add a generic container workflow

---
 .../workflows/generator_container_slsa3.yml   | 163 ++++++++++++++++++
 internal/builders/generic/attest.go           |  13 +-
 2 files changed, 172 insertions(+), 4 deletions(-)
 create mode 100644 .github/workflows/generator_container_slsa3.yml

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
new file mode 100644
index 0000000000..e45d4cf8b4
--- /dev/null
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -0,0 +1,163 @@
+# Copyright 2022 SLSA Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: SLSA container image provenance
+
+permissions:
+  contents: read
+
+env:
+  # Generator
+  BUILDER_BINARY: generic-generator
+  BUILDER_RELEASE_BINARY: slsa-generator-generic-linux-amd64
+  BUILDER_REPOSITORY: slsa-framework/slsa-github-generator
+  # Verifier
+  # NOTE: These VERIFIER_* variables are used for verification of generator
+  # release binaries when the compile-generator input is false.
+  VERIFIER_REPOSITORY: slsa-framework/slsa-verifier
+  VERIFIER_RELEASE_BINARY: slsa-verifier-linux-amd64
+  VERIFIER_RELEASE_BINARY_SHA256: f92fc4e571949c796d7709bb3f0814a733124b0155e484fad095b5ca68b4cb21
+  VERIFIER_RELEASE: v1.1.1
+
+on:
+  workflow_call:
+    secrets:
+      registry-password:
+        description: "Password to log in the container registry."
+        required: false # NOTE: This is actually required right now.
+    inputs:
+      image:
+        description: "The OCI image name."
+        required: true
+        type: string
+      registry-user:
+        description: "Username to log into the container registry."
+        required: false # NOTE: This is actually required right now.
+        type: string
+      # FIXME: support not uploading to registry.
+      # upload-to-registry:
+      #   description: "If true the provenance is pushed to the container registry."
+      #   required: false
+      #   type: boolean
+      #   default: true
+      compile-generator:
+        description: "Build the generator from source. This increases build time by ~2m."
+        required: false
+        type: boolean
+        default: false
+    outputs:
+      attestation-name:
+        description: "The artifact name of the signed provenance"
+        value: ${{ jobs.generator.outputs.attestation-name }}
+
+jobs:
+  # detect-env detects the reusable workflow's repository and ref for use later
+  # in the workflow.
+  detect-env:
+    outputs:
+      repository: ${{ steps.detect.outputs.repository }}
+      ref: ${{ steps.detect.outputs.ref }}
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write # Needed to detect the current reusable repository and ref.
+    steps:
+      - name: Detect the generator ref
+        id: detect
+        uses: slsa-framework/slsa-github-generator/.github/actions/detect-workflow@d995948e8d53cc639c0d3ef69db31dbc243519c4 # v1.1.1
+
+  # generator builds the generator binary and runs it to generate SLSA
+  # provenance.
+  #
+  # If `compile-generator` is true then the generator is compiled
+  # from source at the ref detected by `detect-env`.
+  #
+  # If `compile-generator` is false, then the generator binary is downloaded
+  # with the release at the ref detected by `detect-env`. This must be a tag
+  # reference.
+  generator:
+    outputs:
+      attestation-name: ${{ steps.sign-prov.outputs.attestation-name }}
+      attestation-sha256: ${{ steps.sign-prov.outputs.attestation-sha256 }}
+    runs-on: ubuntu-latest
+    needs: [detect-env]
+    permissions:
+      id-token: write # Needed for keyless.
+      contents: read
+      # actions permissions are needed to read info on the workflow and
+      # workflow run.
+      actions: read
+      packages: write
+    steps:
+      - name: Generate builder
+        uses: slsa-framework/slsa-github-generator/.github/actions/generate-builder@1b4ebe8029b40670c71aae9b9c88be486beb6b49
+        with:
+          repository: "${{ needs.detect-env.outputs.repository }}"
+          ref: "${{ needs.detect-env.outputs.ref }}"
+          go-version: 1.18
+          binary: "${{ env.BUILDER_BINARY }}"
+          compile-builder: "${{ inputs.compile-generator }}"
+          directory: "${{ env.BUILDER_DIR }}/generic"
+
+      # Note: here we need packages permissions
+      - uses: sigstore/cosign-installer@7e0881f8fe90b25e305bbf0309761e9314607e25 # v2.4.0
+      - name: Login
+        env:
+          UNTRUSTED_IMAGE: "${{ inputs.image }}"
+          UNTRUSTED_USERNAME: "${{ inputs.registry-username }}"
+          UNTRUSTED_PASSWORD: "${{ secrets.registry-password }}"
+        run: |
+          set -euo pipefail
+
+          untrusted_registry="docker.io"
+
+          # HACK: Need to figure out a better way to do this.
+          maybe_domain=$(echo "$UNTRUSTED_IMAGE" | cut -f1 -d "/" | grep "\.")
+          if [ "$maybe_domain" != "" ]; then
+            untrusted_registry="$maybe_domain"
+          fi
+
+          echo "login to $untrusted_registry"
+          cosign login "$untrusted_registry" -u "$UNTRUSTED_USERNAME" -p "$UNTRUSTED_PASSWORD"
+
+      - name: Create and sign provenance
+        id: sign-prov
+        shell: bash
+        # NOTE: Inputs and github context are set to environment variables in
+        # order to avoid script injection.
+        # See: https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#understanding-the-risk-of-script-injections
+        env:
+          UNTRUSTED_IMAGE: "${{ inputs.image }}"
+          GITHUB_CONTEXT: "${{ toJSON(github) }}"
+        run: |
+          set -euo pipefail
+
+          # Generate a predicate only.
+          attestation_name="attestation.intoto.jsonl"
+          predicate_name="predicate.json"
+          ./"$BUILDER_BINARY" attest -g="" --predicate="$predicate_name"
+
+          # TODO: Set --no-upload if inputs.upload-to-registry is false.
+          COSIGN_EXPERIMENTAL=1 cosign attest --predicate="$predicate_name" \
+            --type slsaprovenance \
+            --force \
+            "$UNTRUSTED_IMAGE" >"$attestation_name"
+          echo "::set-output name=attestation-name::$attestation_name"
+
+      - name: Upload the signed provenance
+        uses: actions/upload-artifact@3cea5372237819ed00197afe530f5a7ea3e805c8 # v3.1.0
+        with:
+          name: "${{ steps.sign-prov.outputs.attestation-name }}"
+          path: "${{ steps.sign-prov.outputs.attestation-name }}"
+          if-no-files-found: error
+          retention-days: 5
diff --git a/internal/builders/generic/attest.go b/internal/builders/generic/attest.go
index 12845d4154..8e4762bc59 100644
--- a/internal/builders/generic/attest.go
+++ b/internal/builders/generic/attest.go
@@ -158,11 +158,16 @@ run in the context of a Github Actions workflow.`,
 			ghContext, err := github.GetWorkflowContext()
 			check(err)
 
-			parsedSubjects, err := parseSubjects(subjects)
-			check(err)
+			var parsedSubjects []intoto.Subject
+			// We don't actually care about the subjects if we aren't writing an attestation.
+			if attPath != "" {
+				var err error
+				parsedSubjects, err = parseSubjects(subjects)
+				check(err)
 
-			if len(parsedSubjects) == 0 {
-				check(errors.New("expected at least one subject"))
+				if len(parsedSubjects) == 0 {
+					check(errors.New("expected at least one subject"))
+				}
 			}
 
 			ctx := context.Background()

From 212feb7e9d0087398a8578279355a6b81428e87d Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 04:11:14 +0000
Subject: [PATCH 02/24] fix input

---
 .github/workflows/generator_container_slsa3.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index e45d4cf8b4..0da09e4303 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -41,7 +41,7 @@ on:
         description: "The OCI image name."
         required: true
         type: string
-      registry-user:
+      registry-username:
         description: "Username to log into the container registry."
         required: false # NOTE: This is actually required right now.
         type: string

From 4821dc220a87770701a14c00c9cfee21f8a67152 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 05:27:32 +0000
Subject: [PATCH 03/24] update hashes

---
 .github/workflows/generator_container_slsa3.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 0da09e4303..2204e98fca 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -74,7 +74,7 @@ jobs:
     steps:
       - name: Detect the generator ref
         id: detect
-        uses: slsa-framework/slsa-github-generator/.github/actions/detect-workflow@d995948e8d53cc639c0d3ef69db31dbc243519c4 # v1.1.1
+        uses: slsa-framework/slsa-github-generator/.github/actions/detect-workflow@49e648aa7f5f4f88513b6cd54f6b189516184e6b
 
   # generator builds the generator binary and runs it to generate SLSA
   # provenance.
@@ -100,7 +100,7 @@ jobs:
       packages: write
     steps:
       - name: Generate builder
-        uses: slsa-framework/slsa-github-generator/.github/actions/generate-builder@1b4ebe8029b40670c71aae9b9c88be486beb6b49
+        uses: slsa-framework/slsa-github-generator/.github/actions/generate-builder@49e648aa7f5f4f88513b6cd54f6b189516184e6b
         with:
           repository: "${{ needs.detect-env.outputs.repository }}"
           ref: "${{ needs.detect-env.outputs.ref }}"

From e6a8759f320ef6873f0744116ac30eb08863947e Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 05:47:28 +0000
Subject: [PATCH 04/24] Avoid OIDC client creation errors on PRs

---
 .github/actions/detect-workflow/main.go      | 26 ++++++++++----------
 .github/actions/detect-workflow/main_test.go |  8 ++++--
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/.github/actions/detect-workflow/main.go b/.github/actions/detect-workflow/main.go
index 0a66903452..89e880fb78 100644
--- a/.github/actions/detect-workflow/main.go
+++ b/.github/actions/detect-workflow/main.go
@@ -28,14 +28,14 @@ import (
 )
 
 type action struct {
-	getenv func(string) string
-	event  map[string]any
-	client *github.OIDCClient
+	getenv    func(string) string
+	event     map[string]any
+	getClient func() (*github.OIDCClient, error)
 }
 
 // TODO(github.com/slsa-framework/slsa-github-generator/issues/164): use the github context via the shared library
 
-func newAction(getenv func(string) string, c *github.OIDCClient) (*action, error) {
+func newAction(getenv func(string) string, getClient func() (*github.OIDCClient, error)) (*action, error) {
 	eventPath := getenv("GITHUB_EVENT_PATH")
 	if eventPath == "" {
 		return nil, errors.New("GITHUB_EVENT_PATH not set")
@@ -52,9 +52,9 @@ func newAction(getenv func(string) string, c *github.OIDCClient) (*action, error
 	}
 
 	return &action{
-		getenv: getenv,
-		event:  event,
-		client: c,
+		getenv:    getenv,
+		event:     event,
+		getClient: getClient,
 	}, nil
 }
 
@@ -107,7 +107,11 @@ func (a *action) getRepoRef(ctx context.Context) (string, string, error) {
 		}
 		audience = path.Join(audience, "detect-workflow")
 
-		t, err := a.client.Token(ctx, []string{audience})
+		client, err := a.getClient()
+		if err != nil {
+			return "", "", fmt.Errorf("creating OIDC client: %w", err)
+		}
+		t, err := client.Token(ctx, []string{audience})
 		if err != nil {
 			return "", "", fmt.Errorf("getting OIDC token: %w", err)
 		}
@@ -136,11 +140,7 @@ func (a *action) getRepoRef(ctx context.Context) (string, string, error) {
 }
 
 func main() {
-	c, err := github.NewOIDCClient()
-	if err != nil {
-		log.Fatal(err)
-	}
-	a, err := newAction(os.Getenv, c)
+	a, err := newAction(os.Getenv, github.NewOIDCClient)
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/.github/actions/detect-workflow/main_test.go b/.github/actions/detect-workflow/main_test.go
index 89950c69a5..7c70b40af9 100644
--- a/.github/actions/detect-workflow/main_test.go
+++ b/.github/actions/detect-workflow/main_test.go
@@ -122,7 +122,9 @@ func Test_action_getRepoRef(t *testing.T) {
 				}
 				return ""
 			},
-			client: c,
+			getClient: func() (*github.OIDCClient, error) {
+				return c, nil
+			},
 		}
 
 		repo, ref, err := a.getRepoRef(context.Background())
@@ -151,7 +153,9 @@ func Test_action_getRepoRef(t *testing.T) {
 				}
 				return env[k]
 			},
-			client: c,
+			getClient: func() (*github.OIDCClient, error) {
+				return c, nil
+			},
 			event: map[string]any{
 				"pull_request": map[string]any{
 					"head": map[string]any{

From 1fba8203bf6ff0d003bddf54bb77676965ae6ea9 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 05:55:52 +0000
Subject: [PATCH 05/24] Add BUILDER_DIR to generic workflow

---
 .github/workflows/generator_generic_slsa3.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/generator_generic_slsa3.yml b/.github/workflows/generator_generic_slsa3.yml
index eb2764719e..62221e4800 100644
--- a/.github/workflows/generator_generic_slsa3.yml
+++ b/.github/workflows/generator_generic_slsa3.yml
@@ -29,6 +29,8 @@ env:
   VERIFIER_RELEASE_BINARY: slsa-verifier-linux-amd64
   VERIFIER_RELEASE_BINARY_SHA256: f92fc4e571949c796d7709bb3f0814a733124b0155e484fad095b5ca68b4cb21
   VERIFIER_RELEASE: v1.1.1
+  # Builder location
+  BUILDER_DIR: internal/builders
 
 on:
   workflow_call:

From a41b963c2cbe5cd784c7b83c0167157709a7aa98 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 06:21:42 +0000
Subject: [PATCH 06/24] Add BUILDER_DIR

---
 .github/workflows/generator_container_slsa3.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 2204e98fca..43eba2c39f 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -29,6 +29,8 @@ env:
   VERIFIER_RELEASE_BINARY: slsa-verifier-linux-amd64
   VERIFIER_RELEASE_BINARY_SHA256: f92fc4e571949c796d7709bb3f0814a733124b0155e484fad095b5ca68b4cb21
   VERIFIER_RELEASE: v1.1.1
+  # Builder location
+  BUILDER_DIR: internal/builders
 
 on:
   workflow_call:
@@ -107,6 +109,7 @@ jobs:
           go-version: 1.18
           binary: "${{ env.BUILDER_BINARY }}"
           compile-builder: "${{ inputs.compile-generator }}"
+          # NOTE: We are using the generic generator.
           directory: "${{ env.BUILDER_DIR }}/generic"
 
       # Note: here we need packages permissions

From 894ddf8520e55c5c95a8b3dd064b095252aa00f0 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Fri, 1 Jul 2022 06:59:18 +0000
Subject: [PATCH 07/24] Fix args to builder

---
 .github/workflows/generator_container_slsa3.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 43eba2c39f..76660b0de2 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -148,7 +148,7 @@ jobs:
           # Generate a predicate only.
           attestation_name="attestation.intoto.jsonl"
           predicate_name="predicate.json"
-          ./"$BUILDER_BINARY" attest -g="" --predicate="$predicate_name"
+          ./"$BUILDER_BINARY" attest --signature="" --predicate="$predicate_name"
 
           # TODO: Set --no-upload if inputs.upload-to-registry is false.
           COSIGN_EXPERIMENTAL=1 cosign attest --predicate="$predicate_name" \

From f4ce48f0b3d72fb3a544aac99c49b94d4ee0282a Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Tue, 5 Jul 2022 01:08:55 +0000
Subject: [PATCH 08/24] Sign the image as well

---
 .github/workflows/generator_container_slsa3.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 76660b0de2..5eb62456bd 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -150,6 +150,9 @@ jobs:
           predicate_name="predicate.json"
           ./"$BUILDER_BINARY" attest --signature="" --predicate="$predicate_name"
 
+          # FIXME: is this necessary?
+          COSIGN_EXPERIMENTAL=1 cosign sign "$UNTRUSTED_IMAGE"
+
           # TODO: Set --no-upload if inputs.upload-to-registry is false.
           COSIGN_EXPERIMENTAL=1 cosign attest --predicate="$predicate_name" \
             --type slsaprovenance \

From 99f70ed2b06f32ed79a9b207a1f089f4b3d938bf Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Tue, 5 Jul 2022 01:33:09 +0000
Subject: [PATCH 09/24] don't sign for now

---
 .github/workflows/generator_container_slsa3.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 5eb62456bd..9095fc7ca6 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -151,7 +151,7 @@ jobs:
           ./"$BUILDER_BINARY" attest --signature="" --predicate="$predicate_name"
 
           # FIXME: is this necessary?
-          COSIGN_EXPERIMENTAL=1 cosign sign "$UNTRUSTED_IMAGE"
+          # COSIGN_EXPERIMENTAL=1 cosign sign "$UNTRUSTED_IMAGE"
 
           # TODO: Set --no-upload if inputs.upload-to-registry is false.
           COSIGN_EXPERIMENTAL=1 cosign attest --predicate="$predicate_name" \

From d37c7e243b73ffa757ed5e77576869574b3349bc Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Tue, 5 Jul 2022 02:15:57 +0000
Subject: [PATCH 10/24] Updates to inputs and domain parsing

---
 .../workflows/generator_container_slsa3.yml   | 44 ++++---------------
 1 file changed, 8 insertions(+), 36 deletions(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 9095fc7ca6..dde37294fe 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -37,7 +37,7 @@ on:
     secrets:
       registry-password:
         description: "Password to log in the container registry."
-        required: false # NOTE: This is actually required right now.
+        required: true
     inputs:
       image:
         description: "The OCI image name."
@@ -45,23 +45,13 @@ on:
         type: string
       registry-username:
         description: "Username to log into the container registry."
-        required: false # NOTE: This is actually required right now.
+        required: true
         type: string
-      # FIXME: support not uploading to registry.
-      # upload-to-registry:
-      #   description: "If true the provenance is pushed to the container registry."
-      #   required: false
-      #   type: boolean
-      #   default: true
       compile-generator:
         description: "Build the generator from source. This increases build time by ~2m."
         required: false
         type: boolean
         default: false
-    outputs:
-      attestation-name:
-        description: "The artifact name of the signed provenance"
-        value: ${{ jobs.generator.outputs.attestation-name }}
 
 jobs:
   # detect-env detects the reusable workflow's repository and ref for use later
@@ -88,9 +78,6 @@ jobs:
   # with the release at the ref detected by `detect-env`. This must be a tag
   # reference.
   generator:
-    outputs:
-      attestation-name: ${{ steps.sign-prov.outputs.attestation-name }}
-      attestation-sha256: ${{ steps.sign-prov.outputs.attestation-sha256 }}
     runs-on: ubuntu-latest
     needs: [detect-env]
     permissions:
@@ -122,10 +109,12 @@ jobs:
         run: |
           set -euo pipefail
 
+          # NOTE: Some docker images are of the form <org>/<name>
+          # Here we get the first part and check if it has a '.' or ':'
+          # character in it to see if it's a domain name.
+          # See: https://stackoverflow.com/questions/37861791/how-are-docker-image-names-parsed#37867949
           untrusted_registry="docker.io"
-
-          # HACK: Need to figure out a better way to do this.
-          maybe_domain=$(echo "$UNTRUSTED_IMAGE" | cut -f1 -d "/" | grep "\.")
+          maybe_domain=$(echo "$UNTRUSTED_IMAGE" | cut -f1 -d "/" | grep -E "\.|:")
           if [ "$maybe_domain" != "" ]; then
             untrusted_registry="$maybe_domain"
           fi
@@ -136,9 +125,6 @@ jobs:
       - name: Create and sign provenance
         id: sign-prov
         shell: bash
-        # NOTE: Inputs and github context are set to environment variables in
-        # order to avoid script injection.
-        # See: https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#understanding-the-risk-of-script-injections
         env:
           UNTRUSTED_IMAGE: "${{ inputs.image }}"
           GITHUB_CONTEXT: "${{ toJSON(github) }}"
@@ -146,24 +132,10 @@ jobs:
           set -euo pipefail
 
           # Generate a predicate only.
-          attestation_name="attestation.intoto.jsonl"
           predicate_name="predicate.json"
           ./"$BUILDER_BINARY" attest --signature="" --predicate="$predicate_name"
 
-          # FIXME: is this necessary?
-          # COSIGN_EXPERIMENTAL=1 cosign sign "$UNTRUSTED_IMAGE"
-
-          # TODO: Set --no-upload if inputs.upload-to-registry is false.
           COSIGN_EXPERIMENTAL=1 cosign attest --predicate="$predicate_name" \
             --type slsaprovenance \
             --force \
-            "$UNTRUSTED_IMAGE" >"$attestation_name"
-          echo "::set-output name=attestation-name::$attestation_name"
-
-      - name: Upload the signed provenance
-        uses: actions/upload-artifact@3cea5372237819ed00197afe530f5a7ea3e805c8 # v3.1.0
-        with:
-          name: "${{ steps.sign-prov.outputs.attestation-name }}"
-          path: "${{ steps.sign-prov.outputs.attestation-name }}"
-          if-no-files-found: error
-          retention-days: 5
+            "$UNTRUSTED_IMAGE"

From 9b4cf527098d47ec9da93c57fb51402ee5701a07 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Tue, 5 Jul 2022 03:22:26 +0000
Subject: [PATCH 11/24] Add basic usage docs for container workflow

---
 internal/builders/container/README.md | 261 ++++++++++++++++++++++++++
 1 file changed, 261 insertions(+)
 create mode 100644 internal/builders/container/README.md

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
new file mode 100644
index 0000000000..08a25ee6e7
--- /dev/null
+++ b/internal/builders/container/README.md
@@ -0,0 +1,261 @@
+# Generation of SLSA3+ provenance for container images
+
+This document explains how to generate SLSA provenance for container images.
+
+This can be done by adding an additional step to your existing Github Actions
+workflow to call a [reusable
+workflow](https://docs.github.com/en/actions/using-workflows/reusing-workflows)
+to generate generic SLSA provenance. We'll call this workflow the "container
+workflow" from now on.
+
+The container workflow differs from ecosystem specific builders (like the [Go
+builder](../go)) which build the artifacts as well as generate provenance. This
+project simply generates provenance as a separate step in an existing workflow.
+
+---
+
+- [Project Status](#project-status)
+- [Benefits of Provenance](#benefits-of-provenance)
+- [Generating Provenance](#generating-provenance)
+  - [Getting Started](#getting-started)
+  - [Supported Triggers](#supported-triggers)
+  - [Workflow Inputs](#workflow-inputs)
+  - [Workflow Outputs](#workflow-outputs)
+  - [Provenance Format](#provenance-format)
+  - [Provenance Example](#provenance-example)
+
+---
+
+## Project Status
+
+This workflow is currently under active development. The API could change while
+approaching an initial release.
+
+## Benefits of Provenance
+
+Using the generic workflow will generate a non-forgeable attestation to the
+container image using the identity of the GitHub workflow. This can be used
+to create a positive attestation to a container image coming from your
+repository.
+
+That means that once your users verify the image they have downloaded they
+can be sure that the image was created by your repository's workflow and
+hasn't been tampered with.
+
+## Generating Provenance
+
+The container workflow uses a Github Actions reusable workflow to generate the
+provenance.
+
+### Getting Started
+
+To get started, you will need to add some steps to your current workflow. We
+will assume you have an existing Github Actions workflow to build your project.
+
+```yaml
+provenance:
+  needs: [build]
+  permissions:
+    actions: read
+    id-token: write
+    contents: read
+    packages: write
+  if: startsWith(github.ref, 'refs/tags/')
+  # TODO(https://github.com/slsa-framework/slsa-github-generator/issues/492): Use a tagged release once we have one.
+  uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@main
+  with:
+    image: ${{ needs.build.outputs.tag }}
+    registry-username: ${{ github.actor }}
+    # TODO(https://github.com/slsa-framework/slsa-github-generator/issues/492): Remove after GA release.
+    compile-generator: true
+  secrets:
+    registry-password: ${{ secrets.GITHUB_TOKEN }}
+```
+
+Here's an example of what it might look like all together.
+
+```yaml
+jobs:
+  # This step builds our image, pushes it, and outputs the repo hash digest.
+  build:
+    permissions:
+      contents: read
+      packages: write
+    outputs:
+      tag: ${{ steps.hash.outputs.tag }}
+      sha: ${{ steps.hash.outputs.sha }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the repository
+        uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b # v2.3.4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@dc7b9719a96d48369863986a06765841d7ea23f6 # v2.0.0
+
+      - name: Authenticate Docker
+        uses: docker/login-action@49ed152c8eca782a232dede0303416e8f356c37b # v2.0.0
+        with:
+          registry: ${{ env.IMAGE_REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@69f6fc9d46f2f8bf0d5491e4aabe0bb8c6a4678a # v4.0.1
+        with:
+          images: ${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@e551b19e49efd4e98792db7592c17c09b89db8d8 # v3.0.0
+        id: build
+        with:
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+      - name: Output digest
+        id: hash
+        env:
+          IMAGE_TAGS: ${{ steps.meta.outputs.tags }}
+          SHA: ${{ steps.build.outputs.digest }}
+        run: |
+          # sha output of docker/build-push-action is of the form 'sha256:<digest>'
+          sha=$(echo $SHA | cut -d':' -f2)
+          # docker/build-push-action outputs multiple tags including latest.
+          # It seems to put latest at the end of the list.
+          tag=$(echo "$IMAGE_TAGS" | head -n1)
+          echo "::set-output name=tag::$tag"
+          echo "::set-output name=sha::$sha"
+
+  # This step calls the container workflow to generate provenance and push it to
+  # the container registry.
+  provenance:
+    needs: [build]
+    permissions:
+      actions: read
+      id-token: write
+      contents: read
+      packages: write
+    if: startsWith(github.ref, 'refs/tags/')
+    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@main
+    with:
+      # XXX: should this use the sha instead of the tag?
+      image: ${{ needs.build.outputs.tag }}
+      registry-username: ${{ github.actor }}
+      # TODO(https://github.com/slsa-framework/slsa-github-generator/issues/492): Remove after GA release.
+      compile-generator: true
+    secrets:
+      registry-password: ${{ secrets.GITHUB_TOKEN }}
+```
+
+### Supported Triggers
+
+The following [GitHub trigger events](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows) are fully supported and tested:
+
+- `schedule`
+- `push` (including new tags)
+- `release`
+- Manual run via `workflow_dispatch`
+
+However, in practice, most triggers should work with the exception of
+`pull_request`. If you would like support for `pull_request`, please tell us
+about your use case on [issue #358](https://github.com/slsa-framework/slsa-github-generator/issues/358). If
+you have an issue in all other triggers please submit a [new
+issue](https://github.com/slsa-framework/slsa-github-generator/issues/new/choose).
+
+### Workflow Inputs
+
+The [container workflow](https://github.com/slsa-framework/slsa-github-generator/blob/main/.github/workflows/generator_container_slsa3.yml) accepts the following inputs:
+
+Inputs:
+
+| Name                | Required | Description                                                        |
+| ------------------- | -------- | ------------------------------------------------------------------ |
+| `image`             | yes      | The OCI image name.                                                |
+| `registry-username` | yes      | Username to log into the container registry.                       |
+| `compile-generator` | false    | Build the generator from source. This increases build time by ~2m. |
+
+Secrets:
+
+| Name                | Required | Description                                |
+| ------------------- | -------- | ------------------------------------------ |
+| `registry-password` | yes      | Password to log in the container registry. |
+
+### Provenance Format
+
+The project generates SLSA provenance with the following values.
+
+| Name                         | Value                                                          | Description                                                                                                                                                                                                            |
+| ---------------------------- | -------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `buildType`                  | `"https://github.com/slsa-framework/slsa-github-generator@v1"` | Identifies a generic GitHub Actions build.                                                                                                                                                                             |
+| `metadata.buildInvocationID` | `"[run_id]-[run_attempt]"`                                     | The GitHub Actions [`run_id`](https://docs.github.com/en/actions/learn-github-actions/contexts#github-context) does not update when a workflow is re-run. Run attempt is added to make the build invocation ID unique. |
+
+### Provenance Example
+
+The following is an example of the generated proveanance. Provenance is
+generated as an [in-toto](https://in-toto.io/) statement with a SLSA predicate.
+
+```json
+{
+  "_type": "https://in-toto.io/Statement/v0.1",
+  "predicateType": "https://slsa.dev/provenance/v0.2",
+  "subject": [
+    {
+      "name": "ghcr.io/ianlewis/actions-test",
+      "digest": {
+        "sha256": "8ae83e5b11e4cc8257f5f4d1023081ba1c72e8e60e8ed6cacd0d53a4ca2d142b"
+      }
+    },
+  ],
+  "predicate": {
+    "builder": {
+      "id": "https://github.com/slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@refs/tags/v1.1.1"
+    },
+    "buildType": "https://github.com/slsa-framework/slsa-github-generator@v1",
+    "invocation": {
+      "configSource": {
+        "uri": "git+https://github.com/ianlewis/actions-test@refs/heads/main.git",
+        "digest": {
+          "sha1": "e491e4b2ce5bc76fb103729b61b04d3c46d8a192"
+        },
+        "entryPoint": ".github/workflows/generic-container.yml"
+      },
+      "parameters": {},
+      "environment": {
+        "github_actor": "ianlewis",
+        "github_actor_id": "49289",
+        "github_base_ref": "",
+        "github_event_name": "push",
+        "github_event_payload": {...},
+        "github_head_ref": "",
+        "github_ref": "refs/tags/v0.0.9",
+        "github_ref_type": "tag",
+        "github_repository_id": "474793590",
+        "github_repository_owner": "ianlewis",
+        "github_repository_owner_id": "49289",
+        "github_run_attempt": "1",
+        "github_run_id": "2556669934",
+        "github_run_number": "12",
+        "github_sha1": "e491e4b2ce5bc76fb103729b61b04d3c46d8a192"
+      }
+    },
+    "metadata": {
+      "buildInvocationID": "2556669934-1",
+      "completeness": {
+        "parameters": true,
+        "environment": false,
+        "materials": false
+      },
+      "reproducible": false
+    },
+    "materials": [
+      {
+        "uri": "git+https://github.com/ianlewis/actions-test@refs/tags/v0.0.9",
+        "digest": {
+          "sha1": "e491e4b2ce5bc76fb103729b61b04d3c46d8a192"
+        }
+      }
+    ]
+  }
+}
+```

From 8b548af664d224cff38571a787185f7d1bb4270c Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Wed, 6 Jul 2022 00:15:50 +0000
Subject: [PATCH 12/24] docs fixes

---
 internal/builders/container/README.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index 08a25ee6e7..e034ff6050 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -33,7 +33,7 @@ approaching an initial release.
 
 ## Benefits of Provenance
 
-Using the generic workflow will generate a non-forgeable attestation to the
+Using the container workflow will generate a non-forgeable attestation to the
 container image using the identity of the GitHub workflow. This can be used
 to create a positive attestation to a container image coming from your
 repository.
@@ -209,7 +209,7 @@ generated as an [in-toto](https://in-toto.io/) statement with a SLSA predicate.
   ],
   "predicate": {
     "builder": {
-      "id": "https://github.com/slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@refs/tags/v1.1.1"
+      "id": "https://github.com/slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@refs/tags/v1.1.1"
     },
     "buildType": "https://github.com/slsa-framework/slsa-github-generator@v1",
     "invocation": {

From 7276289fe50efea3d7096e781b474eb083ca9f07 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Wed, 6 Jul 2022 01:24:15 +0000
Subject: [PATCH 13/24] Update example to use the image digest

---
 internal/builders/container/README.md | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index e034ff6050..37dfdcfa4e 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -82,8 +82,7 @@ jobs:
       contents: read
       packages: write
     outputs:
-      tag: ${{ steps.hash.outputs.tag }}
-      sha: ${{ steps.hash.outputs.sha }}
+      image-and-digest: ${{ steps.digest.outputs.image }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout the repository
@@ -113,19 +112,17 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
 
-      - name: Output digest
-        id: hash
+      - name: Output image and digest
+        id: digest
         env:
-          IMAGE_TAGS: ${{ steps.meta.outputs.tags }}
-          SHA: ${{ steps.build.outputs.digest }}
+          DIGEST: ${{ steps.build.outputs.digest }}
         run: |
-          # sha output of docker/build-push-action is of the form 'sha256:<digest>'
-          sha=$(echo $SHA | cut -d':' -f2)
-          # docker/build-push-action outputs multiple tags including latest.
-          # It seems to put latest at the end of the list.
-          tag=$(echo "$IMAGE_TAGS" | head -n1)
-          echo "::set-output name=tag::$tag"
-          echo "::set-output name=sha::$sha"
+          # NOTE: We need to use the image and digest in order to make sure
+          # that the image we attest has not been modified.
+          # NOTE: The digest output from docker/build-push-action is of the
+          # form "sha256:<digest>"
+          image_name="${IMAGE_REGISTRY}/${IMAGE_NAME}@${DIGEST}"
+          echo "::set-output name=image::$image_name"
 
   # This step calls the container workflow to generate provenance and push it to
   # the container registry.
@@ -139,8 +136,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/')
     uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@main
     with:
-      # XXX: should this use the sha instead of the tag?
-      image: ${{ needs.build.outputs.tag }}
+      image: ${{ needs.build.outputs.image-and-digest }}
       registry-username: ${{ github.actor }}
       # TODO(https://github.com/slsa-framework/slsa-github-generator/issues/492): Remove after GA release.
       compile-generator: true

From ed01d20b5c955171cb3d112006d9b40153c0c4b6 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Wed, 6 Jul 2022 01:32:46 +0000
Subject: [PATCH 14/24] Add a separate digest input

---
 .github/workflows/generator_container_slsa3.yml | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index dde37294fe..270602ca13 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -40,7 +40,11 @@ on:
         required: true
     inputs:
       image:
-        description: "The OCI image name."
+        description: "The OCI image name. This must not include a tag or digest."
+        required: true
+        type: string
+      digest:
+        description: "The OCI image digest. The image digest of the form '<algorithm>:<digest>' (e.g. 'sha256:abcdef...')"
         required: true
         type: string
       registry-username:
@@ -127,6 +131,7 @@ jobs:
         shell: bash
         env:
           UNTRUSTED_IMAGE: "${{ inputs.image }}"
+          UNTRUSTED_DIGEST: "${{ inputs.digest }}"
           GITHUB_CONTEXT: "${{ toJSON(github) }}"
         run: |
           set -euo pipefail
@@ -138,4 +143,4 @@ jobs:
           COSIGN_EXPERIMENTAL=1 cosign attest --predicate="$predicate_name" \
             --type slsaprovenance \
             --force \
-            "$UNTRUSTED_IMAGE"
+            "${UNTRUSTED_IMAGE}@${UNTRUSTED_DIGEST}"

From a15cb3d2c1b409a960c4a5bd4db9ec5e64e5f911 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Wed, 6 Jul 2022 02:36:57 +0000
Subject: [PATCH 15/24] Add digest input to docs

---
 internal/builders/container/README.md | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index 37dfdcfa4e..f6f4f1eccf 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -20,7 +20,6 @@ project simply generates provenance as a separate step in an existing workflow.
   - [Getting Started](#getting-started)
   - [Supported Triggers](#supported-triggers)
   - [Workflow Inputs](#workflow-inputs)
-  - [Workflow Outputs](#workflow-outputs)
   - [Provenance Format](#provenance-format)
   - [Provenance Example](#provenance-example)
 
@@ -165,11 +164,12 @@ The [container workflow](https://github.com/slsa-framework/slsa-github-generator
 
 Inputs:
 
-| Name                | Required | Description                                                        |
-| ------------------- | -------- | ------------------------------------------------------------------ |
-| `image`             | yes      | The OCI image name.                                                |
-| `registry-username` | yes      | Username to log into the container registry.                       |
-| `compile-generator` | false    | Build the generator from source. This increases build time by ~2m. |
+| Name                | Required | Description                                                                                         |
+| ------------------- | -------- | --------------------------------------------------------------------------------------------------- |
+| `image`             | yes      | The OCI image name. This must not include a tag or digest.                                          |
+| `digest`            | yes      | The OCI image digest. The image digest of the form '<algorithm>:<digest>' (e.g. 'sha256:abcdef...') |
+| `registry-username` | yes      | Username to log into the container registry.                                                        |
+| `compile-generator` | false    | Build the generator from source. This increases build time by ~2m.                                  |
 
 Secrets:
 

From 05e7f7b9c407fa6b81f5a27a23c3d2fb11eb44fe Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Thu, 7 Jul 2022 12:48:45 +0900
Subject: [PATCH 16/24] Update internal/builders/container/README.md

Co-authored-by: Joshua Lock <jlock@vmware.com>
---
 internal/builders/container/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index f6f4f1eccf..2c3be32d3e 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -169,7 +169,7 @@ Inputs:
 | `image`             | yes      | The OCI image name. This must not include a tag or digest.                                          |
 | `digest`            | yes      | The OCI image digest. The image digest of the form '<algorithm>:<digest>' (e.g. 'sha256:abcdef...') |
 | `registry-username` | yes      | Username to log into the container registry.                                                        |
-| `compile-generator` | false    | Build the generator from source. This increases build time by ~2m.                                  |
+| `compile-generator` | false    | Whether to build the generator from source. This increases build time by ~2m.                                  |
 
 Secrets:
 

From 0cf0b4995a45f6f9b06ec09f648fec8975d119c5 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Thu, 7 Jul 2022 03:57:22 +0000
Subject: [PATCH 17/24] Update comments

---
 .github/workflows/generator_container_slsa3.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 270602ca13..c5a5945a97 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -85,11 +85,13 @@ jobs:
     runs-on: ubuntu-latest
     needs: [detect-env]
     permissions:
-      id-token: write # Needed for keyless.
+      # id-token:write is needed to create an OCID token for keyless signing.
+      id-token: write
       contents: read
       # actions permissions are needed to read info on the workflow and
       # workflow run.
       actions: read
+      # packages:write permissions are needed to login and upload attestations.
       packages: write
     steps:
       - name: Generate builder
@@ -103,7 +105,6 @@ jobs:
           # NOTE: We are using the generic generator.
           directory: "${{ env.BUILDER_DIR }}/generic"
 
-      # Note: here we need packages permissions
       - uses: sigstore/cosign-installer@7e0881f8fe90b25e305bbf0309761e9314607e25 # v2.4.0
       - name: Login
         env:

From a4a692241141e4fe18c1863c5b2f13bed92ac024 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Thu, 7 Jul 2022 03:57:44 +0000
Subject: [PATCH 18/24] comment out contents:read to test

---
 .github/workflows/generator_container_slsa3.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index c5a5945a97..6fc0fab484 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -87,7 +87,7 @@ jobs:
     permissions:
       # id-token:write is needed to create an OCID token for keyless signing.
       id-token: write
-      contents: read
+      # contents: read
       # actions permissions are needed to read info on the workflow and
       # workflow run.
       actions: read

From a7c38dcb2e634adc8f25315620e0b543e9aaa8c7 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Thu, 7 Jul 2022 03:59:01 +0000
Subject: [PATCH 19/24] comment out contents:read to test

---
 .github/workflows/generator_container_slsa3.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 6fc0fab484..9e0f0b8e8b 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -14,8 +14,8 @@
 
 name: SLSA container image provenance
 
-permissions:
-  contents: read
+# permissions:
+#   contents: read
 
 env:
   # Generator

From 160b3204fc6332e6d8e588c722b95c6e1dd494cf Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Thu, 7 Jul 2022 04:30:55 +0000
Subject: [PATCH 20/24] remove contents:read permissions

---
 .github/workflows/generator_container_slsa3.yml | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 9e0f0b8e8b..5dfaf039fc 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -14,9 +14,6 @@
 
 name: SLSA container image provenance
 
-# permissions:
-#   contents: read
-
 env:
   # Generator
   BUILDER_BINARY: generic-generator
@@ -87,7 +84,6 @@ jobs:
     permissions:
       # id-token:write is needed to create an OCID token for keyless signing.
       id-token: write
-      # contents: read
       # actions permissions are needed to read info on the workflow and
       # workflow run.
       actions: read

From c12b0a3d0ad1ece50b29c4549048cb73e0f97a6d Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Thu, 7 Jul 2022 04:32:52 +0000
Subject: [PATCH 21/24] remove contents:read from docs

---
 internal/builders/container/README.md | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index 2c3be32d3e..d18f30fb17 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -55,10 +55,9 @@ will assume you have an existing Github Actions workflow to build your project.
 provenance:
   needs: [build]
   permissions:
-    actions: read
-    id-token: write
-    contents: read
-    packages: write
+    actions: read # for detecting the Github Actions environment.
+    id-token: write # for creating OCID tokens for signing.
+    packages: write # for uploading attestations.
   if: startsWith(github.ref, 'refs/tags/')
   # TODO(https://github.com/slsa-framework/slsa-github-generator/issues/492): Use a tagged release once we have one.
   uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@main
@@ -128,10 +127,9 @@ jobs:
   provenance:
     needs: [build]
     permissions:
-      actions: read
-      id-token: write
-      contents: read
-      packages: write
+      actions: read # for detecting the Github Actions environment.
+      id-token: write # for creating OCID tokens for signing.
+      packages: write # for uploading attestations.
     if: startsWith(github.ref, 'refs/tags/')
     uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@main
     with:
@@ -169,7 +167,7 @@ Inputs:
 | `image`             | yes      | The OCI image name. This must not include a tag or digest.                                          |
 | `digest`            | yes      | The OCI image digest. The image digest of the form '<algorithm>:<digest>' (e.g. 'sha256:abcdef...') |
 | `registry-username` | yes      | Username to log into the container registry.                                                        |
-| `compile-generator` | false    | Whether to build the generator from source. This increases build time by ~2m.                                  |
+| `compile-generator` | false    | Whether to build the generator from source. This increases build time by ~2m.                       |
 
 Secrets:
 

From cb48241e96221142f0d55ba2b18698f6c82b1fa9 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Sun, 10 Jul 2022 23:42:10 +0000
Subject: [PATCH 22/24] Fix repository domain check

---
 .github/workflows/generator_container_slsa3.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/generator_container_slsa3.yml b/.github/workflows/generator_container_slsa3.yml
index 5dfaf039fc..4d8989cdab 100644
--- a/.github/workflows/generator_container_slsa3.yml
+++ b/.github/workflows/generator_container_slsa3.yml
@@ -115,7 +115,8 @@ jobs:
           # character in it to see if it's a domain name.
           # See: https://stackoverflow.com/questions/37861791/how-are-docker-image-names-parsed#37867949
           untrusted_registry="docker.io"
-          maybe_domain=$(echo "$UNTRUSTED_IMAGE" | cut -f1 -d "/" | grep -E "\.|:")
+          # NOTE: Do not fail the script if grep does not match.
+          maybe_domain=$(echo "$UNTRUSTED_IMAGE" | cut -f1 -d "/" | { grep -E "\.|:" || true; })
           if [ "$maybe_domain" != "" ]; then
             untrusted_registry="$maybe_domain"
           fi

From 493a82a770c6ff3618d0c3af2d2f15f7f3d90f8d Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Mon, 11 Jul 2022 00:15:47 +0000
Subject: [PATCH 23/24] Update docs

---
 internal/builders/container/README.md | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index d18f30fb17..587c5110fa 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -73,6 +73,10 @@ provenance:
 Here's an example of what it might look like all together.
 
 ```yaml
+env:
+  IMAGE_REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
 jobs:
   # This step builds our image, pushes it, and outputs the repo hash digest.
   build:
@@ -80,7 +84,7 @@ jobs:
       contents: read
       packages: write
     outputs:
-      image-and-digest: ${{ steps.digest.outputs.image }}
+      image: ${{ steps.image.outputs.image }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout the repository
@@ -110,16 +114,12 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
 
-      - name: Output image and digest
-        id: digest
-        env:
-          DIGEST: ${{ steps.build.outputs.digest }}
+      - name: Output image
+        id: image
         run: |
-          # NOTE: We need to use the image and digest in order to make sure
-          # that the image we attest has not been modified.
-          # NOTE: The digest output from docker/build-push-action is of the
-          # form "sha256:<digest>"
-          image_name="${IMAGE_REGISTRY}/${IMAGE_NAME}@${DIGEST}"
+	  # NOTE: Set the image as an output because the `env` context is not
+          # available to the inputs of a reusable workflow call.
+          image_name="${IMAGE_REGISTRY}/${IMAGE_NAME}"
           echo "::set-output name=image::$image_name"
 
   # This step calls the container workflow to generate provenance and push it to
@@ -133,7 +133,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/')
     uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@main
     with:
-      image: ${{ needs.build.outputs.image-and-digest }}
+      image: ${{ needs.build.outputs.image }}
       registry-username: ${{ github.actor }}
       # TODO(https://github.com/slsa-framework/slsa-github-generator/issues/492): Remove after GA release.
       compile-generator: true

From d0c9e91190220cef4b2ff282ff5f3b8467316da2 Mon Sep 17 00:00:00 2001
From: Ian Lewis <ianlewis@google.com>
Date: Mon, 11 Jul 2022 00:20:07 +0000
Subject: [PATCH 24/24] fix whitespace

---
 internal/builders/container/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/internal/builders/container/README.md b/internal/builders/container/README.md
index 587c5110fa..05094e4eaf 100644
--- a/internal/builders/container/README.md
+++ b/internal/builders/container/README.md
@@ -117,7 +117,7 @@ jobs:
       - name: Output image
         id: image
         run: |
-	  # NOTE: Set the image as an output because the `env` context is not
+          # NOTE: Set the image as an output because the `env` context is not
           # available to the inputs of a reusable workflow call.
           image_name="${IMAGE_REGISTRY}/${IMAGE_NAME}"
           echo "::set-output name=image::$image_name"