src

user_agent.go (13854B)

---

 package middleware
 
 import (
 	"context"
 	"fmt"
 	"os"
 	"runtime"
 	"sort"
 	"strings"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/smithy-go/middleware"
 	smithyhttp "github.com/aws/smithy-go/transport/http"
 )
 
 var languageVersion = strings.TrimPrefix(runtime.Version(), "go")
 
 // SDKAgentKeyType is the metadata type to add to the SDK agent string
 type SDKAgentKeyType int
 
 // The set of valid SDKAgentKeyType constants. If an unknown value is assigned for SDKAgentKeyType it will
 // be mapped to AdditionalMetadata.
 const (
 	_ SDKAgentKeyType = iota
 	APIMetadata
 	OperatingSystemMetadata
 	LanguageMetadata
 	EnvironmentMetadata
 	FeatureMetadata
 	ConfigMetadata
 	FrameworkMetadata
 	AdditionalMetadata
 	ApplicationIdentifier
 	FeatureMetadata2
 )
 
 // Hardcoded value to specify which version of the user agent we're using
 const uaMetadata = "ua/2.1"
 
 func (k SDKAgentKeyType) string() string {
 	switch k {
 	case APIMetadata:
 		return "api"
 	case OperatingSystemMetadata:
 		return "os"
 	case LanguageMetadata:
 		return "lang"
 	case EnvironmentMetadata:
 		return "exec-env"
 	case FeatureMetadata:
 		return "ft"
 	case ConfigMetadata:
 		return "cfg"
 	case FrameworkMetadata:
 		return "lib"
 	case ApplicationIdentifier:
 		return "app"
 	case FeatureMetadata2:
 		return "m"
 	case AdditionalMetadata:
 		fallthrough
 	default:
 		return "md"
 	}
 }
 
 const execEnvVar = `AWS_EXECUTION_ENV`
 
 var validChars = map[rune]bool{
 	'!': true, '#': true, '$': true, '%': true, '&': true, '\'': true, '*': true, '+': true,
 	'-': true, '.': true, '^': true, '_': true, '`': true, '|': true, '~': true,
 }
 
 // UserAgentFeature enumerates tracked SDK features.
 type UserAgentFeature string
 
 // Enumerates UserAgentFeature.
 const (
 	UserAgentFeatureResourceModel UserAgentFeature = "A" // n/a (we don't generate separate resource types)
 
 	UserAgentFeatureWaiter    = "B"
 	UserAgentFeaturePaginator = "C"
 
 	UserAgentFeatureRetryModeLegacy   = "D" // n/a (equivalent to standard)
 	UserAgentFeatureRetryModeStandard = "E"
 	UserAgentFeatureRetryModeAdaptive = "F"
 
 	UserAgentFeatureS3Transfer      = "G"
 	UserAgentFeatureS3CryptoV1N     = "H" // n/a (crypto client is external)
 	UserAgentFeatureS3CryptoV2      = "I" // n/a
 	UserAgentFeatureS3ExpressBucket = "J"
 	UserAgentFeatureS3AccessGrants  = "K" // not yet implemented
 
 	UserAgentFeatureGZIPRequestCompression = "L"
 
 	UserAgentFeatureProtocolRPCV2CBOR = "M"
 
 	UserAgentFeatureAccountIDEndpoint      = "O" // DO NOT IMPLEMENT: rules output is not currently defined. SDKs should not parse endpoints for feature information.
 	UserAgentFeatureAccountIDModePreferred = "P"
 	UserAgentFeatureAccountIDModeDisabled  = "Q"
 	UserAgentFeatureAccountIDModeRequired  = "R"
 
 	UserAgentFeatureRequestChecksumCRC32          = "U"
 	UserAgentFeatureRequestChecksumCRC32C         = "V"
 	UserAgentFeatureRequestChecksumCRC64          = "W"
 	UserAgentFeatureRequestChecksumSHA1           = "X"
 	UserAgentFeatureRequestChecksumSHA256         = "Y"
 	UserAgentFeatureRequestChecksumWhenSupported  = "Z"
 	UserAgentFeatureRequestChecksumWhenRequired   = "a"
 	UserAgentFeatureResponseChecksumWhenSupported = "b"
 	UserAgentFeatureResponseChecksumWhenRequired  = "c"
 
 	UserAgentFeatureDynamoDBUserAgent = "d" // not yet implemented
 
 	UserAgentFeatureCredentialsCode                 = "e"
 	UserAgentFeatureCredentialsJvmSystemProperties  = "f" // n/a (this is not a JVM sdk)
 	UserAgentFeatureCredentialsEnvVars              = "g"
 	UserAgentFeatureCredentialsEnvVarsStsWebIDToken = "h"
 	UserAgentFeatureCredentialsStsAssumeRole        = "i"
 	UserAgentFeatureCredentialsStsAssumeRoleSaml    = "j" // not yet implemented
 	UserAgentFeatureCredentialsStsAssumeRoleWebID   = "k"
 	UserAgentFeatureCredentialsStsFederationToken   = "l" // not yet implemented
 	UserAgentFeatureCredentialsStsSessionToken      = "m" // not yet implemented
 	UserAgentFeatureCredentialsProfile              = "n"
 	UserAgentFeatureCredentialsProfileSourceProfile = "o"
 	UserAgentFeatureCredentialsProfileNamedProvider = "p"
 	UserAgentFeatureCredentialsProfileStsWebIDToken = "q"
 	UserAgentFeatureCredentialsProfileSso           = "r"
 	UserAgentFeatureCredentialsSso                  = "s"
 	UserAgentFeatureCredentialsProfileSsoLegacy     = "t"
 	UserAgentFeatureCredentialsSsoLegacy            = "u"
 	UserAgentFeatureCredentialsProfileProcess       = "v"
 	UserAgentFeatureCredentialsProcess              = "w"
 	UserAgentFeatureCredentialsBoto2ConfigFile      = "x" // n/a (this is not boto/Python)
 	UserAgentFeatureCredentialsAwsSdkStore          = "y" // n/a (this is used by .NET based sdk)
 	UserAgentFeatureCredentialsHTTP                 = "z"
 	UserAgentFeatureCredentialsIMDS                 = "0"
 
 	UserAgentFeatureBearerServiceEnvVars = "3"
 
 	UserAgentFeatureCredentialsProfileLogin = "AC"
 	UserAgentFeatureCredentialsLogin        = "AD"
 )
 
 var credentialSourceToFeature = map[aws.CredentialSource]UserAgentFeature{
 	aws.CredentialSourceCode:                 UserAgentFeatureCredentialsCode,
 	aws.CredentialSourceEnvVars:              UserAgentFeatureCredentialsEnvVars,
 	aws.CredentialSourceEnvVarsSTSWebIDToken: UserAgentFeatureCredentialsEnvVarsStsWebIDToken,
 	aws.CredentialSourceSTSAssumeRole:        UserAgentFeatureCredentialsStsAssumeRole,
 	aws.CredentialSourceSTSAssumeRoleSaml:    UserAgentFeatureCredentialsStsAssumeRoleSaml,
 	aws.CredentialSourceSTSAssumeRoleWebID:   UserAgentFeatureCredentialsStsAssumeRoleWebID,
 	aws.CredentialSourceSTSFederationToken:   UserAgentFeatureCredentialsStsFederationToken,
 	aws.CredentialSourceSTSSessionToken:      UserAgentFeatureCredentialsStsSessionToken,
 	aws.CredentialSourceProfile:              UserAgentFeatureCredentialsProfile,
 	aws.CredentialSourceProfileSourceProfile: UserAgentFeatureCredentialsProfileSourceProfile,
 	aws.CredentialSourceProfileNamedProvider: UserAgentFeatureCredentialsProfileNamedProvider,
 	aws.CredentialSourceProfileSTSWebIDToken: UserAgentFeatureCredentialsProfileStsWebIDToken,
 	aws.CredentialSourceProfileSSO:           UserAgentFeatureCredentialsProfileSso,
 	aws.CredentialSourceSSO:                  UserAgentFeatureCredentialsSso,
 	aws.CredentialSourceProfileSSOLegacy:     UserAgentFeatureCredentialsProfileSsoLegacy,
 	aws.CredentialSourceSSOLegacy:            UserAgentFeatureCredentialsSsoLegacy,
 	aws.CredentialSourceProfileProcess:       UserAgentFeatureCredentialsProfileProcess,
 	aws.CredentialSourceProcess:              UserAgentFeatureCredentialsProcess,
 	aws.CredentialSourceHTTP:                 UserAgentFeatureCredentialsHTTP,
 	aws.CredentialSourceIMDS:                 UserAgentFeatureCredentialsIMDS,
 	aws.CredentialSourceProfileLogin:         UserAgentFeatureCredentialsProfileLogin,
 	aws.CredentialSourceLogin:                UserAgentFeatureCredentialsLogin,
 }
 
 // RequestUserAgent is a build middleware that set the User-Agent for the request.
 type RequestUserAgent struct {
 	sdkAgent, userAgent *smithyhttp.UserAgentBuilder
 	features            map[UserAgentFeature]struct{}
 }
 
 // NewRequestUserAgent returns a new requestUserAgent which will set the User-Agent and X-Amz-User-Agent for the
 // request.
 //
 // User-Agent example:
 //
 //	aws-sdk-go-v2/1.2.3
 //
 // X-Amz-User-Agent example:
 //
 //	aws-sdk-go-v2/1.2.3 md/GOOS/linux md/GOARCH/amd64 lang/go/1.15
 func NewRequestUserAgent() *RequestUserAgent {
 	userAgent, sdkAgent := smithyhttp.NewUserAgentBuilder(), smithyhttp.NewUserAgentBuilder()
 	addProductName(userAgent)
 	addUserAgentMetadata(userAgent)
 	addProductName(sdkAgent)
 
 	r := &RequestUserAgent{
 		sdkAgent:  sdkAgent,
 		userAgent: userAgent,
 		features:  map[UserAgentFeature]struct{}{},
 	}
 
 	addSDKMetadata(r)
 
 	return r
 }
 
 func addSDKMetadata(r *RequestUserAgent) {
 	r.AddSDKAgentKey(OperatingSystemMetadata, getNormalizedOSName())
 	r.AddSDKAgentKeyValue(LanguageMetadata, "go", languageVersion)
 	r.AddSDKAgentKeyValue(AdditionalMetadata, "GOOS", runtime.GOOS)
 	r.AddSDKAgentKeyValue(AdditionalMetadata, "GOARCH", runtime.GOARCH)
 	if ev := os.Getenv(execEnvVar); len(ev) > 0 {
 		r.AddSDKAgentKey(EnvironmentMetadata, ev)
 	}
 }
 
 func addProductName(builder *smithyhttp.UserAgentBuilder) {
 	builder.AddKeyValue(aws.SDKName, aws.SDKVersion)
 }
 
 func addUserAgentMetadata(builder *smithyhttp.UserAgentBuilder) {
 	builder.AddKey(uaMetadata)
 }
 
 // AddUserAgentKey retrieves a requestUserAgent from the provided stack, or initializes one.
 func AddUserAgentKey(key string) func(*middleware.Stack) error {
 	return func(stack *middleware.Stack) error {
 		requestUserAgent, err := getOrAddRequestUserAgent(stack)
 		if err != nil {
 			return err
 		}
 		requestUserAgent.AddUserAgentKey(key)
 		return nil
 	}
 }
 
 // AddUserAgentKeyValue retrieves a requestUserAgent from the provided stack, or initializes one.
 func AddUserAgentKeyValue(key, value string) func(*middleware.Stack) error {
 	return func(stack *middleware.Stack) error {
 		requestUserAgent, err := getOrAddRequestUserAgent(stack)
 		if err != nil {
 			return err
 		}
 		requestUserAgent.AddUserAgentKeyValue(key, value)
 		return nil
 	}
 }
 
 // AddSDKAgentKey retrieves a requestUserAgent from the provided stack, or initializes one.
 func AddSDKAgentKey(keyType SDKAgentKeyType, key string) func(*middleware.Stack) error {
 	return func(stack *middleware.Stack) error {
 		requestUserAgent, err := getOrAddRequestUserAgent(stack)
 		if err != nil {
 			return err
 		}
 		requestUserAgent.AddSDKAgentKey(keyType, key)
 		return nil
 	}
 }
 
 // AddSDKAgentKeyValue retrieves a requestUserAgent from the provided stack, or initializes one.
 func AddSDKAgentKeyValue(keyType SDKAgentKeyType, key, value string) func(*middleware.Stack) error {
 	return func(stack *middleware.Stack) error {
 		requestUserAgent, err := getOrAddRequestUserAgent(stack)
 		if err != nil {
 			return err
 		}
 		requestUserAgent.AddSDKAgentKeyValue(keyType, key, value)
 		return nil
 	}
 }
 
 // AddRequestUserAgentMiddleware registers a requestUserAgent middleware on the stack if not present.
 func AddRequestUserAgentMiddleware(stack *middleware.Stack) error {
 	_, err := getOrAddRequestUserAgent(stack)
 	return err
 }
 
 func getOrAddRequestUserAgent(stack *middleware.Stack) (*RequestUserAgent, error) {
 	id := (*RequestUserAgent)(nil).ID()
 	bm, ok := stack.Build.Get(id)
 	if !ok {
 		bm = NewRequestUserAgent()
 		err := stack.Build.Add(bm, middleware.After)
 		if err != nil {
 			return nil, err
 		}
 	}
 
 	requestUserAgent, ok := bm.(*RequestUserAgent)
 	if !ok {
 		return nil, fmt.Errorf("%T for %s middleware did not match expected type", bm, id)
 	}
 
 	return requestUserAgent, nil
 }
 
 // AddUserAgentKey adds the component identified by name to the User-Agent string.
 func (u *RequestUserAgent) AddUserAgentKey(key string) {
 	u.userAgent.AddKey(strings.Map(rules, key))
 }
 
 // AddUserAgentKeyValue adds the key identified by the given name and value to the User-Agent string.
 func (u *RequestUserAgent) AddUserAgentKeyValue(key, value string) {
 	u.userAgent.AddKeyValue(strings.Map(rules, key), strings.Map(rules, value))
 }
 
 // AddUserAgentFeature adds the feature ID to the tracking list to be emitted
 // in the final User-Agent string.
 func (u *RequestUserAgent) AddUserAgentFeature(feature UserAgentFeature) {
 	u.features[feature] = struct{}{}
 }
 
 // AddSDKAgentKey adds the component identified by name to the User-Agent string.
 func (u *RequestUserAgent) AddSDKAgentKey(keyType SDKAgentKeyType, key string) {
 	// TODO: should target sdkAgent
 	u.userAgent.AddKey(keyType.string() + "/" + strings.Map(rules, key))
 }
 
 // AddSDKAgentKeyValue adds the key identified by the given name and value to the User-Agent string.
 func (u *RequestUserAgent) AddSDKAgentKeyValue(keyType SDKAgentKeyType, key, value string) {
 	// TODO: should target sdkAgent
 	u.userAgent.AddKeyValue(keyType.string(), strings.Map(rules, key)+"#"+strings.Map(rules, value))
 }
 
 // AddCredentialsSource adds the credential source as a feature on the User-Agent string
 func (u *RequestUserAgent) AddCredentialsSource(source aws.CredentialSource) {
 	x, ok := credentialSourceToFeature[source]
 	if ok {
 		u.AddUserAgentFeature(x)
 	}
 }
 
 // ID the name of the middleware.
 func (u *RequestUserAgent) ID() string {
 	return "UserAgent"
 }
 
 // HandleBuild adds or appends the constructed user agent to the request.
 func (u *RequestUserAgent) HandleBuild(ctx context.Context, in middleware.BuildInput, next middleware.BuildHandler) (
 	out middleware.BuildOutput, metadata middleware.Metadata, err error,
 ) {
 	switch req := in.Request.(type) {
 	case *smithyhttp.Request:
 		u.addHTTPUserAgent(req)
 		// TODO: To be re-enabled
 		// u.addHTTPSDKAgent(req)
 	default:
 		return out, metadata, fmt.Errorf("unknown transport type %T", in)
 	}
 
 	return next.HandleBuild(ctx, in)
 }
 
 func (u *RequestUserAgent) addHTTPUserAgent(request *smithyhttp.Request) {
 	const userAgent = "User-Agent"
 	if len(u.features) > 0 {
 		updateHTTPHeader(request, userAgent, buildFeatureMetrics(u.features))
 	}
 	updateHTTPHeader(request, userAgent, u.userAgent.Build())
 }
 
 func (u *RequestUserAgent) addHTTPSDKAgent(request *smithyhttp.Request) {
 	const sdkAgent = "X-Amz-User-Agent"
 	updateHTTPHeader(request, sdkAgent, u.sdkAgent.Build())
 }
 
 func updateHTTPHeader(request *smithyhttp.Request, header string, value string) {
 	var current string
 	if v := request.Header[header]; len(v) > 0 {
 		current = v[0]
 	}
 	if len(current) > 0 {
 		current = value + " " + current
 	} else {
 		current = value
 	}
 	request.Header[header] = append(request.Header[header][:0], current)
 }
 
 func rules(r rune) rune {
 	switch {
 	case r >= '0' && r <= '9':
 		return r
 	case r >= 'A' && r <= 'Z' || r >= 'a' && r <= 'z':
 		return r
 	case validChars[r]:
 		return r
 	default:
 		return '-'
 	}
 }
 
 func buildFeatureMetrics(features map[UserAgentFeature]struct{}) string {
 	fs := make([]string, 0, len(features))
 	for f := range features {
 		fs = append(fs, string(f))
 	}
 
 	sort.Strings(fs)
 	return fmt.Sprintf("%s/%s", FeatureMetadata2.string(), strings.Join(fs, ","))
 }