fix: ECR authentication (#409)

* chore: Adding makefile targets for local building.

* fix: Implement proper parsing of different ECR auth mechanisms.

* chore: Fix typos and cleanup Makefil [skip ci]

GNUmakefile

@@ -2,11 +2,28 @@ TEST?=$$(go list ./... |grep -v 'vendor')
 GOFMT_FILES?=$$(find . -name '*.go' |grep -v vendor)
 PKG_NAME=internal/provider
 
+# Values to install the provider locally for testing purposes
+HOSTNAME=registry.terraform.io
+NAMESPACE=kreuzwerker
+NAME=docker
+BINARY=terraform-provider-${NAME}
+VERSION=9.9.9
+OS_ARCH=darwin_arm64
+
+.PHONY: build test testacc vet fmt fmtcheck errcheck test-compile website-link-check website-lint website-lint-fix
+
 default: build
 
 build: fmtcheck
 	go install
 
+local-build:
+	go build -o ${BINARY}
+
+local-install: local-build
+	mkdir -p ~/.terraform.d/plugins/${HOSTNAME}/${NAMESPACE}/${NAME}/${VERSION}/${OS_ARCH}
+	mv ${BINARY} ~/.terraform.d/plugins/${HOSTNAME}/${NAMESPACE}/${NAME}/${VERSION}/${OS_ARCH}
+
 setup:
 	go install github.com/katbyte/terrafmt
 	go install github.com/client9/misspell/cmd/misspell
@@ -90,8 +107,6 @@ website-lint-fix:
 	@docker run --rm -v $(PWD):/markdown 06kellyjac/markdownlint-cli --fix docs/
 	@terrafmt fmt ./docs --pattern '*.md'
 
-.PHONY: build test testacc vet fmt fmtcheck errcheck test-compile website-link-check website-lint website-lint-fix
-
 chlog-%:
 	@echo "Generating CHANGELOG.md"
 	git-chglog --next-tag $* -o CHANGELOG.md

internal/provider/authentication_helpers.go

@@ -0,0 +1,50 @@
+package provider
+
+import (
+	b64 "encoding/base64"
+	"log"
+	"regexp"
+	"strings"
+)
+
+// ECR HTTP authentication needs Bearer token in the Authorization header
+// This token is an JWT which was b64 encoded again
+// Depending on the aws cli command, the returned token is different
+// "aws ecr get-login-password" is a simply JWT, which needs to be prefixed with "AWS:" and then b64 encoded
+// "aws ecr get-authorization-token" is the best case, everything is encoded properly
+// in case someone passes an base64 decoded token from "aws ecr get-authorization-token" we need to b64 encode it again
+func normalizeECRPasswordForHTTPUsage(password string) string {
+	if strings.HasPrefix(password, "ey") {
+		return b64.StdEncoding.EncodeToString([]byte("AWS:" + password))
+	} else if strings.HasPrefix(password, "AWS:") {
+		return b64.StdEncoding.EncodeToString([]byte(password))
+	}
+	return password
+}
+
+// Docker operations need a JWT, so this function basically does the opposite as `normalizeECRPasswordForHTTPUsage`
+// aws ecr get-authorization-token does not return a JWT, but a base64 encoded string which we need to decode
+func normalizeECRPasswordForDockerCLIUsage(password string) string {
+	if strings.HasPrefix(password, "ey") {
+		return password
+	}
+
+	if !strings.HasPrefix(password, "AWS:") {
+		decodedPassword, err := b64.StdEncoding.DecodeString(password)
+		if err != nil {
+			log.Fatalf("Error creating registry request: %s", err)
+		}
+		password = string(decodedPassword)
+	}
+
+	return password[4:]
+}
+
+func isECRRepositoryURL(url string) bool {
+	if url == "public.ecr.aws" {
+		return true
+	}
+	// Regexp is based on the ecr urls shown in https://docs.aws.amazon.com/AmazonECR/latest/userguide/registry_auth.html
+	var ecrRexp = regexp.MustCompile(`^.*?dkr\.ecr\..*?\.amazonaws\.com$`)
+	return ecrRexp.MatchString(url)
+}

internal/provider/authentication_helpers_test.go

@@ -0,0 +1,19 @@
+package provider
+
+import "testing"
+
+func TestIsECRRepositoryURL(t *testing.T) {
+
+	if !isECRRepositoryURL("2385929435838.dkr.ecr.eu-central-1.amazonaws.com") {
+		t.Fatalf("Expected true")
+	}
+	if !isECRRepositoryURL("39e39fmgvkgd.dkr.ecr.us-east-1.amazonaws.com") {
+		t.Fatalf("Expected true")
+	}
+	if isECRRepositoryURL("39e39fmgvkgd.dkr.ecrus-east-1.amazonaws.com") {
+		t.Fatalf("Expected false")
+	}
+	if !isECRRepositoryURL("public.ecr.aws") {
+		t.Fatalf("Expected true")
+	}
+}

internal/provider/data_source_docker_registry_image.go

@@ -102,10 +102,15 @@ func getImageDigest(registry, image, tag, username, password string, insecureSki
 	}
 
 	if username != "" {
-		if registry != "ghcr.io" {
+		if registry != "ghcr.io" && !isECRRepositoryURL(registry) && registry != "gcr.io" {
 			req.SetBasicAuth(username, password)
 		} else {
-			req.Header.Add("Authorization", "Bearer "+b64.StdEncoding.EncodeToString([]byte(password)))
+			if isECRRepositoryURL(registry) {
+				password = normalizeECRPasswordForHTTPUsage(password)
+				req.Header.Add("Authorization", "Basic "+password)
+			} else {
+				req.Header.Add("Authorization", "Bearer "+b64.StdEncoding.EncodeToString([]byte(password)))
+			}
 		}
 	}
 

internal/provider/provider.go

@@ -223,8 +223,12 @@ func providerSetToRegistryAuth(authList []interface{}) (*AuthConfigs, error) {
 		// username/password or the given config file
 		if username, ok := auth["username"]; ok && username.(string) != "" {
 			log.Println("[DEBUG] Using username for registry auths:", username)
+			password := auth["password"].(string)
+			if isECRRepositoryURL(registryHostname) {
+				password = normalizeECRPasswordForDockerCLIUsage(password)
+			}
 			authConfig.Username = auth["username"].(string)
-			authConfig.Password = auth["password"].(string)
+			authConfig.Password = password
 
 			// Note: check for config_file_content first because config_file has a default which would be used
 			// nevertheless config_file_content is set or not. The default has to be kept to check for the