namespacegcs=::google::cloud::storage;using::google::cloud::StatusOr;[](gcs::Clientclient,std::stringconst&bucket_name,std::stringconst&object_name,std::stringconst&signing_account){autodocument=client.GenerateSignedPostPolicyV4(gcs::PolicyDocumentV4{bucket_name,object_name,/*expiration=*/std::chrono::minutes(10),},gcs::AddExtensionFieldOption("x-goog-meta-test","data"),gcs::SigningAccount(signing_account));if(!document)throwstd::move(document).status();// Create the HTML form for the computed policy.std::ostringstreamos;os <<"<form action='" <<document->url <<"' method='POST'"     <<" enctype='multipart/form-data'>\n";for(autoconst&field:document->required_form_fields){os <<"  <input name='" <<field.first <<"' value='" <<field.second       <<"' type='hidden' />\n";}os <<"  <input type='submit' value='Upload File' /><br />\n"     <<"  <input type='file' name='file' /><br />\n"     <<"</form>";std::cout <<"A sample HTML form:\n" <<os.str() <<"\n";}

// Create a signed post policy which can be used to upload a specific object and// expires in 1 hour after creation.UrlSignerurlSigner=UrlSigner.FromCredential(credential);UrlSigner.Optionsoptions=UrlSigner.Options.FromDuration(TimeSpan.FromHours(1)).WithSigningVersion(SigningVersion.V4).WithScheme("https");UrlSigner.PostPolicypostPolicy=UrlSigner.PostPolicy.ForBucketAndKey(bucketName,objectName);postPolicy.SetCustomField(UrlSigner.PostPolicyCustomElement.GoogleMetadata,"x-goog-meta-test","data");UrlSigner.SignedPostPolicysignedPostPolicy=awaiturlSigner.SignAsync(postPolicy,options);// Create an HTML form including all the fields in the signed post policy.StringBuilderform=newStringBuilder();form.AppendLine($"<form action=\"{signedPostPolicy.PostUrl}\" method=\"post\" enctype=\"multipart/form-data\">");foreach(varfieldinsignedPostPolicy.Fields){form.AppendLine($"<input type=\"hidden\" name=\"{field.Key}\" value=\"{field.Value}\">");}// Include the file element. It should always be the last element in the form.form.AppendLine("<input name=\"file\" type=\"file\">");form.AppendLine("<input type=\"submit\" value=\"Upload\">");form.AppendLine("</form>");// You can now save the form to file and serve it as static content// or send it as the response to a request made to your application.File.WriteAllText("PostPolicySimple.html",form.ToString());

importcom.google.cloud.storage.BlobInfo;importcom.google.cloud.storage.PostPolicyV4;importcom.google.cloud.storage.Storage;importcom.google.cloud.storage.StorageOptions;importjava.util.Map;importjava.util.concurrent.TimeUnit;publicclassGenerateSignedPostPolicyV4{/**   * Generating a signed POST policy requires Credentials which implement ServiceAccountSigner.   * These can be set explicitly using the Storage.PostPolicyV4Option.signWith(ServiceAccountSigner)   * option. If you don't, you could also pass a service account signer to StorageOptions, i.e.   * StorageOptions().newBuilder().setCredentials(ServiceAccountSignerCredentials). In this example,   * neither of these options are used, which means the following code only works when the   * credentials are defined via the environment variable GOOGLE_APPLICATION_CREDENTIALS, and those   * credentials are authorized to sign a policy. See the documentation for   * Storage.generateSignedPostPolicyV4 for more details.   */publicstaticvoidgenerateSignedPostPolicyV4(StringprojectId,StringbucketName,StringblobName){// The ID of your GCP project// String projectId = "your-project-id";// The ID of the GCS bucket to upload to// String bucketName = "your-bucket-name"// The name to give the object uploaded to GCS// String blobName = "your-object-name"Storagestorage=StorageOptions.newBuilder().setProjectId(projectId).build().getService();PostPolicyV4.PostFieldsV4fields=PostPolicyV4.PostFieldsV4.newBuilder().setCustomMetadataField("test","data").build();PostPolicyV4policy=storage.generateSignedPostPolicyV4(BlobInfo.newBuilder(bucketName,blobName).build(),10,TimeUnit.MINUTES,fields);StringBuilderhtmlForm=newStringBuilder("<form action='"+policy.getUrl()+"' method='POST' enctype='multipart/form-data'>\n");for(Map.Entry<String,String>entry:policy.getFields().entrySet()){htmlForm.append("  <input name='"+entry.getKey()+"' value='"+entry.getValue()+"' type='hidden' />\n");}htmlForm.append("  <input type='file' name='file'/><br />\n");htmlForm.append("  <input type='submit' value='Upload File'/><br />\n");htmlForm.append("</form>\n");System.out.println("You can use the following HTML form to upload an object to bucket "+bucketName+" for the next ten minutes:");System.out.println(htmlForm.toString());}}

import("context""fmt""html/template""io""time""cloud.google.com/go/storage")// form is a template for an HTML form that will use the data from the signed// post policy.varform=`<form action="{{ .URL }}" method="POST" enctype="multipart/form-data">{{- range $name, $value := .Fields }}<input name="{{ $name }}" value="{{ $value }}" type="hidden"/>{{- end }}<input type="file" name="file"/><br /><input type="submit" value="Upload File" name="submit"/><br /></form>`vartmpl=template.Must(template.New("policyV4").Parse(form))// generateSignedPostPolicyV4 generates a signed post policy.funcgenerateSignedPostPolicyV4(wio.Writer,bucket,objectstring)(*storage.PostPolicyV4,error){// bucket := "bucket-name"// object := "object-name"ctx:=context.Background()client,err:=storage.NewClient(ctx)iferr!=nil{returnnil,fmt.Errorf("storage.NewClient: %w",err)}deferclient.Close()metadata:=map[string]string{"x-goog-meta-test":"data",}// Generating a signed POST policy requires credentials authorized to sign a URL.// You can pass these in through PostPolicyV4Options with one of the following options://    a. a Google service account private key, obtainable from the Google Developers Console//    b. a Google Access ID with iam.serviceAccounts.signBlob permissions//    c. a SignBytes function implementing custom signing// In this example, none of these options are used, which means the// GenerateSignedPostPolicyV4 function attempts to use the same authentication// that was used to instantiatethe Storage client. This authentication must// include a private key or have iam.serviceAccounts.signBlob permissions.opts:=&storage.PostPolicyV4Options{Expires:time.Now().Add(10*time.Minute),Fields:&storage.PolicyV4Fields{Metadata:metadata,},}policy,err:=client.Bucket(bucket).GenerateSignedPostPolicyV4(object,opts)iferr!=nil{returnnil,fmt.Errorf("storage.GenerateSignedPostPolicyV4: %w",err)}// Generate the form, using the data from the policy.iferr=tmpl.Execute(w,policy);err!=nil{returnpolicy,fmt.Errorf("executing template: %w",err)}returnpolicy,nil}

/** * TODO(developer): Uncomment the following lines before running the sample. */// The ID of your GCS bucket// const bucketName = 'your-unique-bucket-name';// The ID of your GCS file// const fileName = 'your-file-name';// Imports the Google Cloud client libraryconst{Storage}=require('@google-cloud/storage');// Creates a clientconststorage=newStorage();asyncfunctiongenerateV4SignedPolicy(){constbucket=storage.bucket(bucketName);constfile=bucket.file(fileName);// These options will allow temporary uploading of a file// through an HTML form.constexpires=Date.now()+10*60*1000;//  10 minutesconstoptions={expires,fields:{'x-goog-meta-test':'data'},};// Get a v4 signed policy for uploading fileconst[response]=awaitfile.generateSignedPostPolicyV4(options);// Create an HTML form with the provided policyletoutput=`<form action="${response.url}" method="POST" enctype="multipart/form-data">\n`;// Include all fields returned in the HTML form as they're requiredfor(constnameofObject.keys(response.fields)){constvalue=response.fields[name];output+=`  <input name="${name}" value="${value}" type="hidden"/>\n`;}output+='  <input type="file" name="file"/><br />\n';output+='  <input type="submit" value="Upload File"/><br />\n';output+='</form>';console.log(output);}generateV4SignedPolicy().catch(console.error);

use Google\Cloud\Storage\StorageClient;/** * Generates a v4 POST Policy to be used in an HTML form and echo's form. * * @param string $bucketName The name of your Cloud Storage bucket. *        (e.g. 'my-bucket') * @param string $objectName The name of your Cloud Storage object. *        (e.g. 'my-object') */function generate_v4_post_policy(string $bucketName, string $objectName): void{    $storage = new StorageClient();    $bucket = $storage->bucket($bucketName);    $response = $bucket->generateSignedPostPolicyV4(        $objectName,        new \DateTime('10 min'),        [            'fields' => [                'x-goog-meta-test' => 'data'            ]        ]    );    $url = $response['url'];    $output = "<form action='$url' method='POST' enctype='multipart/form-data'>" . PHP_EOL;    foreach ($response['fields'] as $name => $value) {        $output .= "  <input name='$name' value='$value' type='hidden'/>" . PHP_EOL;    }    $output .= "  <input type='file' name='file'/><br />" . PHP_EOL;    $output .= "  <input type='submit' value='Upload File' name='submit'/><br />" . PHP_EOL;    $output .= '</form>' . PHP_EOL;    echo $output;}

importdatetimefromgoogle.cloudimportstoragedefgenerate_signed_post_policy_v4(bucket_name,blob_name):"""Generates a v4 POST Policy and prints an HTML form."""# bucket_name = 'your-bucket-name'# blob_name = 'your-object-name'storage_client=storage.Client()policy=storage_client.generate_signed_post_policy_v4(bucket_name,blob_name,expiration=datetime.timedelta(minutes=10),fields={'x-goog-meta-test':'data'})# Create an HTML form with the provided policyheader="<form action='{}' method='POST' enctype='multipart/form-data'>\n"form=header.format(policy["url"])# Include all fields returned in the HTML form as they're requiredforkey,valueinpolicy["fields"].items():form+=f"  <input name='{key}' value='{value}' type='hidden'/>\n"form+="  <input type='file' name='file'/><br />\n"form+="  <input type='submit' value='Upload File' /><br />\n"form+="</form>"print(form)returnform

defgenerate_signed_post_policy_v4bucket_name:,file_name:# The ID of the GCS bucket to upload to# bucket_name = "your-unique-bucket-name"# The name to give the object uploaded to GCS# file_name = "your-file-name"require"google/cloud/storage"storage=Google::Cloud::Storage.newbucket=storage.bucketbucket_namepost_object=bucket.generate_signed_post_policy_v4file_name,expires:600,fields:{"x-goog-meta-test"=>"data"}html_form="<form action='#{post_object.url}' method='POST' enctype='multipart/form-data'>\n"post_object.fields.eachdo|name,value|html_form+="  <input name='#{name}' value='#{value}' type='hidden'/>\n"endhtml_form+="  <input type='file' name='file'/><br />\n"html_form+="  <input type='submit' value='Upload File'/><br />\n"html_form+="</form>\n"puts"You can use the following form to upload an object to bucket#{bucket_name} for the next 10 minutes:\n"putshtml_formpost_objectend