fix: file store to support legacy auth keys in config files (#100)

Backporting
[`e8e4f84`](oras-project/oras-go@e8e4f84)
from `oras-go`.

Fix: #1 
Signed-off-by: Sylvia Lei <lixlei@microsoft.com>

internal/config/config.go

@@ -162,7 +162,20 @@ func (cfg *Config) GetCredential(serverAddress string) (auth.Credential, error)
 
 	authCfgBytes, ok := cfg.authsCache[serverAddress]
 	if !ok {
-		return auth.EmptyCredential, nil
+		// NOTE: the auth key for the server address may have been stored with
+		// a http/https prefix in legacy config files, e.g. "registry.example.com"
+		// can be stored as "https://registry.example.com/".
+		var matched bool
+		for addr, auth := range cfg.authsCache {
+			if toHostname(addr) == serverAddress {
+				matched = true
+				authCfgBytes = auth
+				break
+			}
+		}
+		if !matched {
+			return auth.EmptyCredential, nil
+		}
 	}
 	var authCfg AuthConfig
 	if err := json.Unmarshal(authCfgBytes, &authCfg); err != nil {
@@ -300,3 +313,15 @@ func decodeAuth(authStr string) (username string, password string, err error) {
 	}
 	return username, password, nil
 }
+
+// toHostname normalizes a server address to just its hostname, removing
+// the scheme and the path parts.
+// It is used to match keys in the auths map, which may be either stored as
+// hostname or as hostname including scheme (in legacy docker config files).
+// Reference: https://github.com/docker/cli/blob/v24.0.6/cli/config/credentials/file_store.go#L71
+func toHostname(addr string) string {
+	addr = strings.TrimPrefix(addr, "http://")
+	addr = strings.TrimPrefix(addr, "https://")
+	addr, _, _ = strings.Cut(addr, "/")
+	return addr
+}

internal/config/config_test.go

@@ -180,6 +180,94 @@ func TestConfig_GetCredential_validConfig(t *testing.T) {
 	}
 }
 
+func TestConfig_GetCredential_legacyConfig(t *testing.T) {
+	cfg, err := Load("../../testdata/legacy_auths_config.json")
+	if err != nil {
+		t.Fatal("Load() error =", err)
+	}
+
+	tests := []struct {
+		name          string
+		serverAddress string
+		want          auth.Credential
+		wantErr       bool
+	}{
+		{
+			name:          "Regular address matched",
+			serverAddress: "registry1.example.com",
+			want: auth.Credential{
+				Username: "username1",
+				Password: "password1",
+			},
+		},
+		{
+			name:          "Another entry for the same address matched",
+			serverAddress: "https://registry1.example.com/",
+			want: auth.Credential{
+				Username: "foo",
+				Password: "bar",
+			},
+		},
+		{
+			name:          "Address with different scheme unmached",
+			serverAddress: "http://registry1.example.com/",
+			want:          auth.EmptyCredential,
+		},
+		{
+			name:          "Address with http prefix matched",
+			serverAddress: "registry2.example.com",
+			want: auth.Credential{
+				Username: "username2",
+				Password: "password2",
+			},
+		},
+		{
+			name:          "Address with https prefix matched",
+			serverAddress: "registry3.example.com",
+			want: auth.Credential{
+				Username: "username3",
+				Password: "password3",
+			},
+		},
+		{
+			name:          "Address with http prefix and / suffix matched",
+			serverAddress: "registry4.example.com",
+			want: auth.Credential{
+				Username: "username4",
+				Password: "password4",
+			},
+		},
+		{
+			name:          "Address with https prefix and / suffix matched",
+			serverAddress: "registry5.example.com",
+			want: auth.Credential{
+				Username: "username5",
+				Password: "password5",
+			},
+		},
+		{
+			name:          "Address with https prefix and path suffix matched",
+			serverAddress: "registry6.example.com",
+			want: auth.Credential{
+				Username: "username6",
+				Password: "password6",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := cfg.GetCredential(tt.serverAddress)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Config.GetCredential() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("Config.GetCredential() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
 func TestConfig_GetCredential_invalidConfig(t *testing.T) {
 	cfg, err := Load("../../testdata/invalid_auths_entry_config.json")
 	if err != nil {
@@ -1314,3 +1402,51 @@ func Test_decodeAuth(t *testing.T) {
 		})
 	}
 }
+
+func Test_toHostname(t *testing.T) {
+	tests := []struct {
+		name string
+		addr string
+		want string
+	}{
+		{
+			addr: "http://test.example.com",
+			want: "test.example.com",
+		},
+		{
+			addr: "http://test.example.com/",
+			want: "test.example.com",
+		},
+		{
+			addr: "http://test.example.com/foo/bar",
+			want: "test.example.com",
+		},
+		{
+			addr: "https://test.example.com",
+			want: "test.example.com",
+		},
+		{
+			addr: "https://test.example.com/",
+			want: "test.example.com",
+		},
+		{
+			addr: "http://test.example.com/foo/bar",
+			want: "test.example.com",
+		},
+		{
+			addr: "test.example.com",
+			want: "test.example.com",
+		},
+		{
+			addr: "test.example.com/foo/bar/",
+			want: "test.example.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := toHostname(tt.addr); got != tt.want {
+				t.Errorf("toHostname() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

testdata/legacy_auths_config.json

@@ -0,0 +1,25 @@
+{
+    "auths": {
+        "registry1.example.com": {
+            "auth": "dXNlcm5hbWUxOnBhc3N3b3JkMQ=="
+        },
+        "http://registry2.example.com": {
+            "auth": "dXNlcm5hbWUyOnBhc3N3b3JkMg=="
+        },
+        "https://registry3.example.com": {
+            "auth": "dXNlcm5hbWUzOnBhc3N3b3JkMw=="
+        },
+        "http://registry4.example.com/": {
+            "auth": "dXNlcm5hbWU0OnBhc3N3b3JkNA=="
+        },
+        "https://registry5.example.com/": {
+            "auth": "dXNlcm5hbWU1OnBhc3N3b3JkNQ=="
+        },
+        "https://registry6.example.com/path/": {
+            "auth": "dXNlcm5hbWU2OnBhc3N3b3JkNg=="
+        },
+        "https://registry1.example.com/": {
+            "auth": "Zm9vOmJhcg=="
+        }
+    }
+}