backend/s3: Adds parameter skip_s3_checksum to skip checksum on upload

internal/backend/remote-state/s3/backend.go

@@ -45,6 +45,7 @@ type Backend struct {
 	kmsKeyID              string
 	ddbTable              string
 	workspaceKeyPrefix    string
+	skipS3Checksum        bool
 }
 
 // ConfigSchema returns a description of the expected configuration
@@ -183,7 +184,7 @@ func (b *Backend) ConfigSchema() *configschema.Block {
 			"skip_credentials_validation": {
 				Type:        cty.Bool,
 				Optional:    true,
-				Description: "Skip the credentials validation via STS API.",
+				Description: "Skip the credentials validation via STS API. Useful for testing and for AWS API implementations that do not have STS available.",
 			},
 			"skip_requesting_account_id": {
 				Type:        cty.Bool,
@@ -200,6 +201,11 @@ func (b *Backend) ConfigSchema() *configschema.Block {
 				Optional:    true,
 				Description: "Skip static validation of region name.",
 			},
+			"skip_s3_checksum": {
+				Type:        cty.Bool,
+				Optional:    true,
+				Description: "Do not include checksum when uploading S3 Objects. Useful for some S3-Compatible APIs.",
+			},
 			"sse_customer_key": {
 				Type:        cty.String,
 				Optional:    true,
@@ -903,6 +909,7 @@ func (b *Backend) Configure(obj cty.Value) tfdiags.Diagnostics {
 	b.serverSideEncryption = boolAttr(obj, "encrypt")
 	b.kmsKeyID = stringAttr(obj, "kms_key_id")
 	b.ddbTable = stringAttr(obj, "dynamodb_table")
+	b.skipS3Checksum = boolAttr(obj, "skip_s3_checksum")
 
 	if _, ok := stringAttrOk(obj, "kms_key_id"); ok {
 		if customerKey := os.Getenv("AWS_SSE_CUSTOMER_KEY"); customerKey != "" {

internal/backend/remote-state/s3/backend_state.go

@@ -151,6 +151,7 @@ func (b *Backend) remoteClient(name string) (*RemoteClient, error) {
 		acl:                   b.acl,
 		kmsKeyID:              b.kmsKeyID,
 		ddbTable:              b.ddbTable,
+		skipS3Checksum:        b.skipS3Checksum,
 	}
 
 	return client, nil

internal/backend/remote-state/s3/backend_test.go

@@ -61,6 +61,15 @@ func TestBackend_impl(t *testing.T) {
 	var _ backend.Backend = new(Backend)
 }
 
+func TestBackend_InternalValidate(t *testing.T) {
+	b := New()
+
+	schema := b.ConfigSchema()
+	if err := schema.InternalValidate(); err != nil {
+		t.Fatalf("failed InternalValidate: %s", err)
+	}
+}
+
 func TestBackendConfig_original(t *testing.T) {
 	testACC(t)
 

internal/backend/remote-state/s3/client.go

@@ -47,6 +47,7 @@ type RemoteClient struct {
 	acl                   string
 	kmsKeyID              string
 	ddbTable              string
+	skipS3Checksum        bool
 }
 
 var (
@@ -182,6 +183,10 @@ func (c *RemoteClient) get(ctx context.Context) (*remote.Payload, error) {
 }
 
 func (c *RemoteClient) Put(data []byte) error {
+	return c.put(data)
+}
+
+func (c *RemoteClient) put(data []byte, optFns ...func(*s3.Options)) error {
 	ctx := context.TODO()
 	log := c.logger(operationClientPut)
 
@@ -193,11 +198,13 @@ func (c *RemoteClient) Put(data []byte) error {
 	sum := md5.Sum(data)
 
 	input := &s3.PutObjectInput{
-		ContentType:       aws.String(contentType),
-		Body:              bytes.NewReader(data),
-		Bucket:            aws.String(c.bucketName),
-		Key:               aws.String(c.path),
-		ChecksumAlgorithm: s3types.ChecksumAlgorithmSha256,
+		ContentType: aws.String(contentType),
+		Body:        bytes.NewReader(data),
+		Bucket:      aws.String(c.bucketName),
+		Key:         aws.String(c.path),
+	}
+	if !c.skipS3Checksum {
+		input.ChecksumAlgorithm = s3types.ChecksumAlgorithmSha256
 	}
 
 	if c.serverSideEncryption {
@@ -219,16 +226,18 @@ func (c *RemoteClient) Put(data []byte) error {
 
 	log.Info("Uploading remote state")
 
-	uploader := manager.NewUploader(c.s3Client)
+	uploader := manager.NewUploader(c.s3Client, func(u *manager.Uploader) {
+		u.ClientOptions = optFns
+	})
 	_, err := uploader.Upload(ctx, input)
 	if err != nil {
-		return fmt.Errorf("failed to upload state: %s", err)
+		return fmt.Errorf("failed to upload state: %w", err)
 	}
 
 	if err := c.putMD5(ctx, sum[:]); err != nil {
 		// if this errors out, we unfortunately have to error out altogether,
 		// since the next Get will inevitably fail.
-		return fmt.Errorf("failed to store state MD5: %s", err)
+		return fmt.Errorf("failed to store state MD5: %w", err)
 	}
 
 	return nil

internal/backend/remote-state/s3/client_test.go

@@ -7,17 +7,22 @@ import (
 	"bytes"
 	"context"
 	"crypto/md5"
+	"errors"
 	"fmt"
 	"io"
 	"testing"
 	"time"
 
 	"github.com/aws/aws-sdk-go-v2/feature/s3/manager"
+	"github.com/aws/aws-sdk-go-v2/service/s3"
 	s3types "github.com/aws/aws-sdk-go-v2/service/s3/types"
+	"github.com/aws/smithy-go/middleware"
+	smithyhttp "github.com/aws/smithy-go/transport/http"
 	"github.com/hashicorp/terraform/internal/backend"
 	"github.com/hashicorp/terraform/internal/states/remote"
 	"github.com/hashicorp/terraform/internal/states/statefile"
 	"github.com/hashicorp/terraform/internal/states/statemgr"
+	"golang.org/x/exp/maps"
 )
 
 func TestRemoteClient_impl(t *testing.T) {
@@ -383,3 +388,106 @@ func (b neverEnding) Read(p []byte) (n int, err error) {
 	}
 	return len(p), nil
 }
+
+func TestRemoteClientSkipS3Checksum(t *testing.T) {
+	testACC(t)
+
+	ctx := context.TODO()
+
+	bucketName := fmt.Sprintf("terraform-remote-s3-test-%x", time.Now().Unix())
+	keyName := "testState"
+
+	testcases := map[string]struct {
+		config   map[string]any
+		expected string
+	}{
+		"default": {
+			config:   map[string]any{},
+			expected: string(s3types.ChecksumAlgorithmSha256),
+		},
+		"true": {
+			config: map[string]any{
+				"skip_s3_checksum": true,
+			},
+			expected: "",
+		},
+		"false": {
+			config: map[string]any{
+				"skip_s3_checksum": false,
+			},
+			expected: string(s3types.ChecksumAlgorithmSha256),
+		},
+	}
+
+	for name, testcase := range testcases {
+		t.Run(name, func(t *testing.T) {
+			config := map[string]interface{}{
+				"bucket": bucketName,
+				"key":    keyName,
+			}
+			maps.Copy(config, testcase.config)
+			b := backend.TestBackendConfig(t, New(), backend.TestWrapConfig(config)).(*Backend)
+
+			createS3Bucket(ctx, t, b.s3Client, bucketName, b.awsConfig.Region)
+			defer deleteS3Bucket(ctx, t, b.s3Client, bucketName, b.awsConfig.Region)
+
+			state, err := b.StateMgr(backend.DefaultStateName)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			c := state.(*remote.State).Client
+			client := c.(*RemoteClient)
+
+			s := statemgr.TestFullInitialState()
+			sf := &statefile.File{State: s}
+			var stateBuf bytes.Buffer
+			if err := statefile.Write(sf, &stateBuf); err != nil {
+				t.Fatal(err)
+			}
+
+			var checksum string
+			err = client.put(stateBuf.Bytes(), func(opts *s3.Options) {
+				opts.APIOptions = append(opts.APIOptions,
+					addRetrieveChecksumHeaderMiddleware(t, &checksum),
+					addCancelRequestMiddleware(),
+				)
+			})
+			if err == nil {
+				t.Fatal("Expected an error, got none")
+			} else if !errors.Is(err, errCancelOperation) {
+				t.Fatalf("Unexpected error: %s", err)
+			}
+
+			if a, e := checksum, testcase.expected; a != e {
+				t.Fatalf("expected %q, got %q", e, a)
+			}
+		})
+	}
+}
+
+func addRetrieveChecksumHeaderMiddleware(t *testing.T, checksum *string) func(*middleware.Stack) error {
+	return func(stack *middleware.Stack) error {
+		return stack.Finalize.Add(
+			retrieveChecksumHeaderMiddleware(t, checksum),
+			middleware.After,
+		)
+	}
+}
+
+func retrieveChecksumHeaderMiddleware(t *testing.T, checksum *string) middleware.FinalizeMiddleware {
+	return middleware.FinalizeMiddlewareFunc(
+		"Test: Retrieve Stuff",
+		func(ctx context.Context, in middleware.FinalizeInput, next middleware.FinalizeHandler) (middleware.FinalizeOutput, middleware.Metadata, error) {
+			t.Helper()
+
+			request, ok := in.Request.(*smithyhttp.Request)
+			if !ok {
+				t.Fatalf("Expected *github.com/aws/smithy-go/transport/http.Request, got %s", fullTypeName(in.Request))
+			}
+
+			*checksum = request.Header.Get("x-amz-sdk-checksum-algorithm")
+
+			return next.HandleFinalize(ctx, in)
+		})
+}

website/docs/language/settings/backends/s3.mdx

@@ -173,9 +173,13 @@ The following configuration is optional:
 * `shared_credentials_file`  - (Optional, **Deprecated**, use `shared_credentials_files` instead) Path to the AWS shared credentials file. Defaults to `~/.aws/credentials`.
 * `shared_credentials_files`  - (Optional) List of paths to AWS shared credentials files. Defaults to `~/.aws/credentials`.
 * `skip_credentials_validation` - (Optional) Skip credentials validation via the STS API.
+  Useful for testing and for AWS API implementations that do not have STS available.
 * `skip_region_validation` - (Optional) Skip validation of provided region name.
-* `skip_requesting_account_id` - (Optional) Whether to skip requesting the account ID. Useful for AWS API implementations that do not have the IAM, STS API, or metadata API.
+* `skip_requesting_account_id` - (Optional) Whether to skip requesting the account ID.
+  Useful for AWS API implementations that do not have the IAM, STS API, or metadata API.
 * `skip_metadata_api_check` - (Optional) Skip usage of EC2 Metadata API.
+* `skip_s3_checksum` - (Optional) Do not include checksum when uploading S3 Objects.
+  Useful for some S3-Compatible APIs.
 * `sts_endpoint` - (Optional, **Deprecated**) Custom endpoint URL for the AWS Security Token Service (STS) API.
   Use `endpoints.sts` instead.
 * `sts_region` - (Optional) AWS region for STS. If unset, AWS will use the same region for STS as other non-STS operations.