Merge pull request #39 from docker/release-v0.4.0

Prepare v0.4.0 release

CHANGELOG.md

@@ -4,6 +4,14 @@ This changelog tracks the releases of docker-credential-helpers.
 This project includes different binaries per platform.
 The platform released is identified after the tag name.
 
+## v0.4.0 (Go client, Mac OS X, Windows, Linux)
+
+- Full implementation for OSX ready
+- Fix some windows issues
+- Implement client.List, change list API
+- mac: delete credentials before adding them to avoid already exist error (fixes #37)
+
+
 ## v0.3.0 (Go client)
 
 - Add Go client library to talk with the native programs.

README.md

@@ -58,11 +58,12 @@ You can see examples of each function in the [client](https://godoc.org/github.c
 
 ## Development
 
-A credential helper can be any program that can read values from the standard input. We use the first argument in the command line to differentiate the kind of command to execute. There are three valid values:
+A credential helper can be any program that can read values from the standard input. We use the first argument in the command line to differentiate the kind of command to execute. There are four valid values:
 
 - `store`: Adds credentials to the keychain. The payload in the standard input is a JSON document with `ServerURL`, `Username` and `Secret`.
 - `get`: Retrieves credentials from the keychain. The payload in the standard input is the raw value for the `ServerURL`.
 - `erase`: Removes credentials from the keychain. The payload in the standard input is the raw value for the `ServerURL`.
+- `list`: Lists stored credentials. There is no standard input payload.
 
 This repository also includes libraries to implement new credentials programs in Go. Adding a new helper program is pretty easy. You can see how the OS X keychain helper works in the [osxkeychain](osxkeychain) directory.
 

client/client.go

@@ -55,11 +55,10 @@ func Get(program ProgramFunc, serverURL string) (*credentials.Credentials, error
 	return resp, nil
 }
 
-// Erase executes a program to remove the server credentails from the native store.
+// Erase executes a program to remove the server credentials from the native store.
 func Erase(program ProgramFunc, serverURL string) error {
 	cmd := program("erase")
 	cmd.Input(strings.NewReader(serverURL))
-
 	out, err := cmd.Output()
 	if err != nil {
 		t := strings.TrimSpace(string(out))
@@ -68,3 +67,21 @@ func Erase(program ProgramFunc, serverURL string) error {
 
 	return nil
 }
+
+// List executes a program to list server credentials in the native store.
+func List(program ProgramFunc) (map[string]string, error) {
+	cmd := program("list")
+	cmd.Input(strings.NewReader("unused"))
+	out, err := cmd.Output()
+	if err != nil {
+		t := strings.TrimSpace(string(out))
+		return nil, fmt.Errorf("error listing credentials - err: %v, out: `%s`", err, t)
+	}
+
+	var resp map[string]string
+	if err = json.NewDecoder(bytes.NewReader(out)).Decode(&resp); err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}

client/client_test.go

@@ -13,6 +13,7 @@ import (
 
 const (
 	validServerAddress   = "https://index.docker.io/v1"
+	validUsername        = "linus"
 	validServerAddress2  = "https://example.com:5002"
 	invalidServerAddress = "https://foobar.example.com"
 	missingCredsAddress  = "https://missing.docker.io/v1"
@@ -70,6 +71,9 @@ func (m *mockProgram) Output() ([]byte, error) {
 		default:
 			return []byte("error storing credentials"), errProgramExited
 		}
+	case "list":
+		return []byte(fmt.Sprintf(`{"%s": "%s"}`, validServerAddress, validUsername)), nil
+
 	}
 
 	return []byte(fmt.Sprintf("unknown argument %q with %q", m.arg, inS)), errProgramExited
@@ -190,3 +194,14 @@ func TestErase(t *testing.T) {
 		t.Fatalf("Expected error for server %s, got nil", invalidServerAddress)
 	}
 }
+
+func TestList(t *testing.T) {
+	auths, err := List(mockProgramFn)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if username, exists := auths[validServerAddress]; !exists || username != validUsername {
+		t.Fatalf("auths[%s] returned %s, %t; expected %s, %t", validServerAddress, username, exists, validUsername, true)
+	}
+}

credentials/credentials.go

@@ -25,7 +25,7 @@ type Credentials struct {
 func Serve(helper Helper) {
 	var err error
 	if len(os.Args) != 2 {
-		err = fmt.Errorf("Usage: %s <store|get|erase>", os.Args[0])
+		err = fmt.Errorf("Usage: %s <store|get|erase|list>", os.Args[0])
 	}
 
 	if err == nil {
@@ -47,6 +47,8 @@ func HandleCommand(helper Helper, key string, in io.Reader, out io.Writer) error
 		return Get(helper, in, out)
 	case "erase":
 		return Erase(helper, in)
+	case "list":
+		return List(helper, out)
 	}
 	return fmt.Errorf("Unknown credential action `%s`", key)
 }
@@ -127,3 +129,13 @@ func Erase(helper Helper, reader io.Reader) error {
 
 	return helper.Delete(serverURL)
 }
+
+//List returns all the serverURLs of keys in
+//the OS store as a list of strings
+func List(helper Helper, writer io.Writer) error {
+	accts, err := helper.List()
+	if err != nil {
+		return err
+	}
+	return json.NewEncoder(writer).Encode(accts)
+}

credentials/credentials_test.go

@@ -36,6 +36,11 @@ func (m *memoryStore) Get(serverURL string) (string, string, error) {
 	return c.Username, c.Secret, nil
 }
 
+func (m *memoryStore) List() (map[string]string, error) {
+	//Simply a placeholder to let memoryStore be a valid implementation of Helper interface
+	return nil, nil
+}
+
 func TestStore(t *testing.T) {
 	serverURL := "https://index.docker.io/v1/"
 	creds := &Credentials{
@@ -138,3 +143,17 @@ func TestErase(t *testing.T) {
 		t.Fatal("expected error getting missing creds, got empty")
 	}
 }
+
+func TestList(t *testing.T) {
+	//This tests that there is proper input an output into the byte stream
+	//Individual stores are very OS specific and have been tested in osxkeychain and secretservice respectively
+	out := new(bytes.Buffer)
+	h := newMemoryStore()
+	if err := List(h, out); err != nil {
+		t.Fatal(err)
+	}
+	//testing that there is an output
+	if out.Len() == 0 {
+		t.Fatalf("expected output in the writer, got %d", 0)
+	}
+}

credentials/helper.go

@@ -9,4 +9,6 @@ type Helper interface {
 	// Get retrieves credentials from the store.
 	// It returns username and secret as strings.
 	Get(serverURL string) (string, string, error)
+	// List returns the stored serverURLs and their associated usernames.
+	List() (map[string]string, error)
 }

osxkeychain/osxkeychain_darwin.c

@@ -1,4 +1,7 @@
 #include "osxkeychain_darwin.h"
+#include <CoreFoundation/CoreFoundation.h>
+#include <stdio.h>
+#include <string.h>
 
 char *get_error(OSStatus status) {
   char *buf = malloc(128);
@@ -96,3 +99,77 @@ char *keychain_delete(struct Server *server) {
   }
   return NULL;
 }
+
+char * CFStringToCharArr(CFStringRef aString) {
+  if (aString == NULL) {
+    return NULL;
+  }
+  CFIndex length = CFStringGetLength(aString);
+  CFIndex maxSize =
+  CFStringGetMaximumSizeForEncoding(length, kCFStringEncodingUTF8) + 1;
+  char *buffer = (char *)malloc(maxSize);
+  if (CFStringGetCString(aString, buffer, maxSize,
+                         kCFStringEncodingUTF8)) {
+    return buffer;
+  }
+  return NULL;
+}
+
+char *keychain_list(char *** paths, char *** accts, unsigned int *list_l) {
+    CFMutableDictionaryRef query = CFDictionaryCreateMutable (NULL, 1, NULL, NULL);
+    CFDictionaryAddValue(query, kSecClass, kSecClassInternetPassword);
+    CFDictionaryAddValue(query, kSecReturnAttributes, kCFBooleanTrue);
+    CFDictionaryAddValue(query, kSecMatchLimit, kSecMatchLimitAll);
+    //Use this query dictionary
+    CFTypeRef result= NULL;
+    OSStatus status = SecItemCopyMatching(
+    query,
+    &result);
+    //Ran a search and store the results in result
+    if (status) {
+        return get_error(status);
+    }
+    int numKeys = CFArrayGetCount(result);
+    *paths = (char **) malloc((int)sizeof(char *)*numKeys);
+    *accts = (char **) malloc((int)sizeof(char *)*numKeys);
+    //result is of type CFArray
+    for(int i=0; i<numKeys; i++) {
+        CFDictionaryRef currKey = CFArrayGetValueAtIndex(result,i);
+        if (CFDictionaryContainsKey(currKey, CFSTR("path"))) {
+            //Even if a key is stored without an account, Apple defaults it to null so these arrays will be of the same length
+            CFStringRef pathTmp = CFDictionaryGetValue(currKey, CFSTR("path"));
+            CFStringRef acctTmp = CFDictionaryGetValue(currKey, CFSTR("acct"));
+            if (acctTmp == NULL) {
+                acctTmp = CFSTR("account not defined");
+            }
+            char * path = (char *) malloc(CFStringGetLength(pathTmp)+1);
+            path = CFStringToCharArr(pathTmp);
+            path[strlen(path)] = '\0';
+            char * acct = (char *) malloc(CFStringGetLength(acctTmp)+1);
+            acct = CFStringToCharArr(acctTmp);
+            acct[strlen(acct)] = '\0';
+            //We now have all we need, username and servername. Now export this to .go
+            (*paths)[i] = (char *) malloc(sizeof(char)*(strlen(path)+1));
+            memcpy((*paths)[i], path, sizeof(char)*(strlen(path)+1));
+            (*accts)[i] = (char *) malloc(sizeof(char)*(strlen(acct)+1));
+            memcpy((*accts)[i], acct, sizeof(char)*(strlen(acct)+1));
+        }
+        else {
+            char * path = "0";
+            char * acct = "0";
+            (*paths)[i] = (char *) malloc(sizeof(char)*(strlen(path)));
+            memcpy((*paths)[i], path, sizeof(char)*(strlen(path)));
+            (*accts)[i] = (char *) malloc(sizeof(char)*(strlen(acct)));
+            memcpy((*accts)[i], acct, sizeof(char)*(strlen(acct)));
+        }
+    }
+    *list_l = numKeys;
+    return NULL;
+}
+
+void freeListData(char *** data, unsigned int length) {
+     for(int i=0; i<length; i++) {
+        free((*data)[i]);
+     }
+     free(*data);
+}

osxkeychain/osxkeychain_darwin.go

@@ -27,6 +27,8 @@ type Osxkeychain struct{}
 
 // Add adds new credentials to the keychain.
 func (h Osxkeychain) Add(creds *credentials.Credentials) error {
+	h.Delete(creds.ServerURL)
+
 	s, err := splitServer(creds.ServerURL)
 	if err != nil {
 		return err
@@ -83,7 +85,6 @@ func (h Osxkeychain) Get(serverURL string) (string, string, error) {
 	if errMsg != nil {
 		defer C.free(unsafe.Pointer(errMsg))
 		goMsg := C.GoString(errMsg)
-
 		if goMsg == errCredentialsNotFound {
 			return "", "", credentials.NewErrCredentialsNotFound()
 		}
@@ -96,6 +97,38 @@ func (h Osxkeychain) Get(serverURL string) (string, string, error) {
 	return user, pass, nil
 }
 
+// List returns the stored URLs and corresponding usernames.
+func (h Osxkeychain) List() (map[string]string, error) {
+	var pathsC **C.char
+	defer C.free(unsafe.Pointer(pathsC))
+	var acctsC **C.char
+	defer C.free(unsafe.Pointer(acctsC))
+	var listLenC C.uint
+	errMsg := C.keychain_list(&pathsC, &acctsC, &listLenC)
+	if errMsg != nil {
+		defer C.free(unsafe.Pointer(errMsg))
+		goMsg := C.GoString(errMsg)
+		return nil, errors.New(goMsg)
+	}
+
+	defer C.freeListData(&pathsC, listLenC)
+	defer C.freeListData(&acctsC, listLenC)
+
+	var listLen int
+	listLen = int(listLenC)
+	pathTmp := (*[1 << 30]*C.char)(unsafe.Pointer(pathsC))[:listLen:listLen]
+	acctTmp := (*[1 << 30]*C.char)(unsafe.Pointer(acctsC))[:listLen:listLen]
+	//taking the array of c strings into go while ignoring all the stuff irrelevant to credentials-helper
+	resp := make(map[string]string)
+	for i := 0; i < listLen; i++ {
+		if C.GoString(pathTmp[i]) == "0" {
+			continue
+		}
+		resp[C.GoString(pathTmp[i])] = C.GoString(acctTmp[i])
+	}
+	return resp, nil
+}
+
 func splitServer(serverURL string) (*C.struct_Server, error) {
 	u, err := url.Parse(serverURL)
 	if err != nil {

osxkeychain/osxkeychain_darwin.h

@@ -10,3 +10,5 @@ struct Server {
 char *keychain_add(struct Server *server, char *username, char *secret);
 char *keychain_get(struct Server *server, unsigned int *username_l, char **username, unsigned int *secret_l, char **secret);
 char *keychain_delete(struct Server *server);
+char *keychain_list(char *** data, char *** accts, unsigned int *list_l);
+void freeListData(char *** data, unsigned int length);

osxkeychain/osxkeychain_darwin_test.go

@@ -1,9 +1,8 @@
 package osxkeychain
 
 import (
-	"testing"
-
 	"github.com/docker/docker-credential-helpers/credentials"
+	"testing"
 )
 
 func TestOSXKeychainHelper(t *testing.T) {
@@ -12,7 +11,11 @@ func TestOSXKeychainHelper(t *testing.T) {
 		Username:  "foobar",
 		Secret:    "foobarbaz",
 	}
-
+	creds1 := &credentials.Credentials{
+		ServerURL: "https://foobar.docker.io:2376/v2",
+		Username:  "foobarbaz",
+		Secret:    "foobar",
+	}
 	helper := Osxkeychain{}
 	if err := helper.Add(creds); err != nil {
 		t.Fatal(err)
@@ -31,6 +34,21 @@ func TestOSXKeychainHelper(t *testing.T) {
 		t.Fatalf("expected %s, got %s\n", "foobarbaz", secret)
 	}
 
+	auths, err := helper.List()
+	if err != nil || len(auths) == 0 {
+		t.Fatal(err)
+	}
+
+	helper.Add(creds1)
+	defer helper.Delete(creds1.ServerURL)
+	newauths, err := helper.List()
+	if len(newauths)-len(auths) != 1 {
+		if err == nil {
+			t.Fatalf("Error: len(newauths): %d, len(auths): %d", len(newauths), len(auths))
+		}
+		t.Fatalf("Error: len(newauths): %d, len(auths): %d\n Error= %v", len(newauths), len(auths), err)
+	}
+
 	if err := helper.Delete(creds.ServerURL); err != nil {
 		t.Fatal(err)
 	}

secretservice/secretservice_linux.c

@@ -1,4 +1,5 @@
 #include <string.h>
+#include <stdlib.h>
 #include "secretservice_linux.h"
 
 const SecretSchema *docker_get_schema(void)
@@ -96,3 +97,52 @@ GError *get(char *server, char **username, char **secret) {
 	}
 	return NULL;
 }
+
+GError *list(char *** paths, char *** accts, unsigned int *list_l) {
+	GList *items;
+	GError *err = NULL;
+	SecretService *service;
+	SecretSearchFlags flags = SECRET_SEARCH_LOAD_SECRETS | SECRET_SEARCH_ALL | SECRET_SEARCH_UNLOCK;
+	GHashTable *attributes;
+	g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
+	attributes = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
+	service = secret_service_get_sync(SECRET_SERVICE_NONE, NULL, &err);
+	items = secret_service_search_sync(service, NULL, attributes, flags, NULL, &err);
+	int numKeys = g_list_length(items);
+	if (err != NULL) {
+		return err;
+	}
+	*paths = (char **) malloc((int)sizeof(char *)*numKeys);
+	*accts = (char **) malloc((int)sizeof(char *)*numKeys);
+	// items now contains our keys from the gnome keyring
+	// we will now put it in our two lists to return it to go
+	GList *current;
+	int listNumber = 0;
+	for(current = items; current!=NULL; current = current->next) {
+		char *pathTmp = secret_item_get_label(current->data);
+		// you cannot have a key without a label in the gnome keyring
+		char *acctTmp = get_username(current->data);
+		if (acctTmp==NULL) {
+			acctTmp = "account not defined";
+		}
+		char *path = (char *) malloc(strlen(pathTmp));
+		char *acct = (char *) malloc(strlen(acctTmp));
+		path = pathTmp;
+		acct = acctTmp;
+		(*paths)[listNumber] = (char *) malloc(sizeof(char)*(strlen(path)));
+		memcpy((*paths)[listNumber], path, sizeof(char)*(strlen(path)));
+		(*accts)[listNumber] = (char *) malloc(sizeof(char)*(strlen(acct)));
+		memcpy((*accts)[listNumber], acct, sizeof(char)*(strlen(acct)));
+		listNumber = listNumber + 1;
+	}
+	*list_l = numKeys;
+	return NULL;
+}
+
+void freeListData(char *** data, unsigned int length) {
+	int i;
+	for(i=0; i<length; i++) {
+		free((*data)[i]);
+	}
+	free(*data);
+}

secretservice/secretservice_linux.go

@@ -78,3 +78,29 @@ func (h Secretservice) Get(serverURL string) (string, string, error) {
 	}
 	return user, pass, nil
 }
+
+// List returns the stored URLs and corresponding usernames.
+func (h Secretservice) List() (map[string]string, error) {
+	var pathsC **C.char
+	defer C.free(unsafe.Pointer(pathsC))
+	var acctsC **C.char
+	defer C.free(unsafe.Pointer(acctsC))
+	var listLenC C.uint
+	err := C.list(&pathsC, &acctsC, &listLenC)
+	if err != nil {
+		defer C.free(unsafe.Pointer(err))
+		return nil, errors.New("Error from list function in secretservice_linux.c likely due to error in secretservice library")
+	}
+	defer C.freeListData(&pathsC, listLenC)
+	defer C.freeListData(&acctsC, listLenC)
+
+	listLen := int(listLenC)
+	pathTmp := (*[1 << 30]*C.char)(unsafe.Pointer(pathsC))[:listLen:listLen]
+	acctTmp := (*[1 << 30]*C.char)(unsafe.Pointer(acctsC))[:listLen:listLen]
+	resp := make(map[string]string)
+	for i := 0; i < listLen; i++ {
+		resp[C.GoString(pathTmp[i])] = C.GoString(acctTmp[i])
+	}
+
+	return resp, nil
+}

secretservice/secretservice_linux.h

@@ -9,3 +9,5 @@ const SecretSchema *docker_get_schema(void) G_GNUC_CONST;
 GError *add(char *server, char *username, char *secret);
 GError *delete(char *server);
 GError *get(char *server, char **username, char **secret);
+GError *list(char *** paths, char *** accts, unsigned int *list_l);
+void freeListData(char *** data, unsigned int length);

secretservice/secretservice_linux_test.go

@@ -36,6 +36,14 @@ func TestSecretServiceHelper(t *testing.T) {
 	if err := helper.Delete(creds.ServerURL); err != nil {
 		t.Fatal(err)
 	}
+	auths, err := helper.List()
+	if err != nil || len(auths) == 0 {
+		t.Fatal(err)
+	}
+	helper.Add(creds)
+	if newauths, err := helper.List(); (len(newauths) - len(auths)) != 1 {
+		t.Fatal(err)
+	}
 }
 
 func TestMissingCredentials(t *testing.T) {

vendor/github.com/danieljoos/wincred/conversion.go

@@ -1,7 +1,6 @@
 package wincred
 
 import (
-	"C"
 	"encoding/binary"
 	"reflect"
 	"syscall"
@@ -10,6 +9,8 @@ import (
 	"unsafe"
 )
 
+var nullPointer = unsafe.Pointer(uintptr(0))
+
 // Create a Go string using a pointer to a zero-terminated UTF 16 encoded string.
 // See github.com/AllenDang/w32
 func utf16PtrToString(wstr *uint16) string {
@@ -36,8 +37,22 @@ func utf16ToByte(wstr []uint16) (result []byte) {
 	return
 }
 
+// Copies the given C byte array to a Go byte array (see `C.GoBytes`)
+func goBytes(src unsafe.Pointer, len uint32) []byte {
+	if src == nullPointer {
+		return []byte{}
+	}
+	slice := (*[1 << 30]byte)(src)[0:len]
+	rv := make([]byte, len)
+	copy(rv, slice)
+	return rv[:]
+}
+
 // Convert the given CREDENTIAL struct to a more usable structure
 func nativeToCredential(cred *nativeCREDENTIAL) (result *Credential) {
+	if unsafe.Pointer(cred) == nullPointer {
+		return nil
+	}
 	result = new(Credential)
 	result.Comment = utf16PtrToString(cred.Comment)
 	result.TargetName = utf16PtrToString(cred.TargetName)
@@ -45,7 +60,7 @@ func nativeToCredential(cred *nativeCREDENTIAL) (result *Credential) {
 	result.UserName = utf16PtrToString(cred.UserName)
 	result.LastWritten = time.Unix(0, cred.LastWritten.Nanoseconds())
 	result.Persist = CredentialPersistence(cred.Persist)
-	result.CredentialBlob = C.GoBytes(unsafe.Pointer(cred.CredentialBlob), C.int(cred.CredentialBlobSize))
+	result.CredentialBlob = goBytes(unsafe.Pointer(cred.CredentialBlob), cred.CredentialBlobSize)
 	result.Attributes = make([]CredentialAttribute, cred.AttributeCount)
 	attrSliceHeader := reflect.SliceHeader{
 		Data: cred.Attributes,
@@ -56,15 +71,17 @@ func nativeToCredential(cred *nativeCREDENTIAL) (result *Credential) {
 	for i, attr := range attrSlice {
 		resultAttr := &result.Attributes[i]
 		resultAttr.Keyword = utf16PtrToString(attr.Keyword)
-		resultAttr.Value = C.GoBytes(unsafe.Pointer(attr.Value), C.int(attr.ValueSize))
+		resultAttr.Value = goBytes(unsafe.Pointer(attr.Value), attr.ValueSize)
 	}
-
 	return result
 }
 
 // Convert the given Credential object back to a CREDENTIAL struct, which can be used for calling the
 // Windows APIs
 func nativeFromCredential(cred *Credential) (result *nativeCREDENTIAL) {
+	if cred == nil {
+		return nil
+	}
 	result = new(nativeCREDENTIAL)
 	result.Flags = 0
 	result.Type = 0

vendor/github.com/danieljoos/wincred/native.go

@@ -8,12 +8,18 @@ import (
 var (
 	modadvapi32 = syscall.NewLazyDLL("advapi32.dll")
 
-	procCredRead   = modadvapi32.NewProc("CredReadW")
+	procCredRead      proc = modadvapi32.NewProc("CredReadW")
-	procCredWrite  = modadvapi32.NewProc("CredWriteW")
+	procCredWrite     proc = modadvapi32.NewProc("CredWriteW")
-	procCredDelete = modadvapi32.NewProc("CredDeleteW")
+	procCredDelete    proc = modadvapi32.NewProc("CredDeleteW")
-	procCredFree   = modadvapi32.NewProc("CredFree")
+	procCredFree      proc = modadvapi32.NewProc("CredFree")
+	procCredEnumerate proc = modadvapi32.NewProc("CredEnumerateW")
 )
 
+// Interface for syscall.Proc: helps testing
+type proc interface {
+	Call(a ...uintptr) (r1, r2 uintptr, lastErr error)
+}
+
 // http://msdn.microsoft.com/en-us/library/windows/desktop/aa374788(v=vs.85).aspx
 type nativeCREDENTIAL struct {
 	Flags              uint32
@@ -48,6 +54,8 @@ const (
 	naCRED_TYPE_DOMAIN_VISIBLE_PASSWORD nativeCRED_TYPE = 0x4
 	naCRED_TYPE_GENERIC_CERTIFICATE     nativeCRED_TYPE = 0x5
 	naCRED_TYPE_DOMAIN_EXTENDED         nativeCRED_TYPE = 0x6
+
+	naERROR_NOT_FOUND = "Element not found."
 )
 
 // http://msdn.microsoft.com/en-us/library/windows/desktop/aa374804(v=vs.85).aspx
@@ -97,3 +105,33 @@ func nativeCredDelete(cred *Credential, typ nativeCRED_TYPE) error {
 
 	return nil
 }
+
+// https://msdn.microsoft.com/en-us/library/windows/desktop/aa374794(v=vs.85).aspx
+func nativeCredEnumerate(filter string, all bool) ([]*Credential, error) {
+	var count int
+	var pcreds uintptr
+	var filterPtr uintptr
+	if !all {
+		filterUtf16Ptr, _ := syscall.UTF16PtrFromString(filter)
+		filterPtr = uintptr(unsafe.Pointer(filterUtf16Ptr))
+	} else {
+		filterPtr = 0
+	}
+	ret, _, err := procCredEnumerate.Call(
+		filterPtr,
+		0,
+		uintptr(unsafe.Pointer(&count)),
+		uintptr(unsafe.Pointer(&pcreds)),
+	)
+	if ret == 0 {
+		return nil, err
+	}
+	defer procCredFree.Call(pcreds)
+	pcredsSlice := (*[1 << 30]uintptr)(unsafe.Pointer(pcreds))[:count:count]
+	creds := make([]*Credential, count)
+	for i := range creds {
+		creds[i] = nativeToCredential((*nativeCREDENTIAL)(unsafe.Pointer(pcredsSlice[i])))
+	}
+
+	return creds, nil
+}

vendor/github.com/danieljoos/wincred/wincred.go

@@ -67,3 +67,14 @@ func (t *DomainPassword) Delete() (err error) {
 func (t *DomainPassword) SetPassword(pw string) {
 	t.CredentialBlob = utf16ToByte(syscall.StringToUTF16(pw))
 }
+
+// List the contents of the Credentials store
+func List() ([]*Credential, error) {
+	creds, err := nativeCredEnumerate("", true)
+	if err != nil && err.Error() == naERROR_NOT_FOUND {
+		// Ignore ERROR_NOT_FOUND and return an empty list instead
+		creds = []*Credential{}
+		err = nil
+	}
+	return creds, err
+}

wincred/wincred_windows.go

@@ -37,3 +37,17 @@ func (h Wincred) Get(serverURL string) (string, string, error) {
 	}
 	return g.UserName, string(g.CredentialBlob), nil
 }
+
+// List returns the stored URLs and corresponding usernames.
+func (h Wincred) List() (map[string]string, error) {
+	creds, err := winc.List()
+	if err != nil {
+		return nil, err
+	}
+
+	resp := make(map[string]string)
+	for i := range creds {
+		resp[creds[i].TargetName] = creds[i].UserName
+	}
+	return resp, nil
+}

wincred/wincred_windows_test.go

@@ -12,6 +12,11 @@ func TestWinCredHelper(t *testing.T) {
 		Username:  "foobar",
 		Secret:    "foobarbaz",
 	}
+	creds1 := &credentials.Credentials{
+		ServerURL: "https://foobar.docker.io:2376/v2",
+		Username:  "foobarbaz",
+		Secret:    "foobar",
+	}
 
 	helper := Wincred{}
 	if err := helper.Add(creds); err != nil {
@@ -31,6 +36,25 @@ func TestWinCredHelper(t *testing.T) {
 		t.Fatalf("expected %s, got %s\n", "foobarbaz", secret)
 	}
 
+	auths, err := helper.List()
+	if err != nil || len(auths) == 0 {
+		t.Fatal(err)
+	}
+
+	helper.Add(creds1)
+	defer helper.Delete(creds1.ServerURL)
+	newauths, err := helper.List()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(newauths)-len(auths) != 1 {
+		if err == nil {
+			t.Fatalf("Error: len(newauths): %d, len(auths): %d", len(newauths), len(auths))
+		}
+		t.Fatalf("Error: len(newauths): %d, len(auths): %d\n Error= %v", len(newauths), len(auths), err)
+	}
+
 	if err := helper.Delete(creds.ServerURL); err != nil {
 		t.Fatal(err)
 	}