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|
package jwt
import (
"context"
"fmt"
stdhttp "net/http"
"strings"
"google.golang.org/grpc/metadata"
"github.com/go-kit/kit/transport/grpc"
"github.com/go-kit/kit/transport/http"
)
const (
bearer string = "bearer"
bearerFormat string = "Bearer %s"
)
// HTTPToContext moves a JWT from request header to context. Particularly
// useful for servers.
func HTTPToContext() http.RequestFunc {
return func(ctx context.Context, r *stdhttp.Request) context.Context {
token, ok := extractTokenFromAuthHeader(r.Header.Get("Authorization"))
if !ok {
return ctx
}
return context.WithValue(ctx, JWTContextKey, token)
}
}
// ContextToHTTP moves a JWT from context to request header. Particularly
// useful for clients.
func ContextToHTTP() http.RequestFunc {
return func(ctx context.Context, r *stdhttp.Request) context.Context {
token, ok := ctx.Value(JWTContextKey).(string)
if ok {
r.Header.Add("Authorization", generateAuthHeaderFromToken(token))
}
return ctx
}
}
// GRPCToContext moves a JWT from grpc metadata to context. Particularly
// userful for servers.
func GRPCToContext() grpc.ServerRequestFunc {
return func(ctx context.Context, md metadata.MD) context.Context {
// capital "Key" is illegal in HTTP/2.
authHeader, ok := md["authorization"]
if !ok {
return ctx
}
token, ok := extractTokenFromAuthHeader(authHeader[0])
if ok {
ctx = context.WithValue(ctx, JWTContextKey, token)
}
return ctx
}
}
// ContextToGRPC moves a JWT from context to grpc metadata. Particularly
// useful for clients.
func ContextToGRPC() grpc.ClientRequestFunc {
return func(ctx context.Context, md *metadata.MD) context.Context {
token, ok := ctx.Value(JWTContextKey).(string)
if ok {
// capital "Key" is illegal in HTTP/2.
(*md)["authorization"] = []string{generateAuthHeaderFromToken(token)}
}
return ctx
}
}
func extractTokenFromAuthHeader(val string) (token string, ok bool) {
authHeaderParts := strings.Split(val, " ")
if len(authHeaderParts) != 2 || !strings.EqualFold(authHeaderParts[0], bearer) {
return "", false
}
return authHeaderParts[1], true
}
func generateAuthHeaderFromToken(token string) string {
return fmt.Sprintf(bearerFormat, token)
}
|
