Security hardening and code quality improvements

cli/go.mod

@@ -4,7 +4,7 @@ go 1.26.0
 
 require (
 	github.com/azure/azure-dev/cli/azd v0.0.0-20260228002641-8f080b39d69b
-	github.com/jongio/azd-core v0.5.3
+	github.com/jongio/azd-core v0.5.4
 	github.com/magefile/mage v1.15.0
 	github.com/mark3labs/mcp-go v0.43.2
 	github.com/spf13/cobra v1.10.2
@@ -83,12 +83,12 @@ require (
 	go.opentelemetry.io/otel/sdk v1.40.0 // indirect
 	go.opentelemetry.io/otel/trace v1.40.0 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
-	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/crypto v0.48.0 // indirect
 	golang.org/x/exp v0.0.0-20260112195511-716be5621a96 // indirect
-	golang.org/x/net v0.49.0 // indirect
-	golang.org/x/sys v0.40.0 // indirect
-	golang.org/x/term v0.39.0 // indirect
-	golang.org/x/text v0.33.0 // indirect
+	golang.org/x/net v0.51.0 // indirect
+	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/term v0.40.0 // indirect
+	golang.org/x/text v0.34.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260203192932-546029d2fa20 // indirect
 	google.golang.org/grpc v1.78.0 // indirect

cli/go.sum

@@ -123,8 +123,8 @@ github.com/jmespath-community/go-jmespath v1.1.1 h1:bFikPhsi/FdmlZhVgSCd2jj1e7G/
 github.com/jmespath-community/go-jmespath v1.1.1/go.mod h1:4gOyFJsR/Gk+05RgTKYrifT7tBPWD8Lubtb5jRrfy9I=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
-github.com/jongio/azd-core v0.5.3 h1:gCPJs61kUCdRYZZq4Dy4Ncz+S+00rDr9jt5CPpMgBrE=
-github.com/jongio/azd-core v0.5.3/go.mod h1:jQCP+px3Pxb3B0fyShfvSVa3KsWT1j2jGXMsPpQezlI=
+github.com/jongio/azd-core v0.5.4 h1:pCGn+Q+NJ4pJFsojqf0sn5osTHW8mMRzD3O6SjnlFKc=
+github.com/jongio/azd-core v0.5.4/go.mod h1:XeXQJVNJ/+GbBfsYIyDdJ6E3SHCrKlEqnv6eDVqDKQ4=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
 github.com/keybase/go-keychain v0.0.1 h1:way+bWYa6lDppZoZcgMbYsvC7GxljxrskdNInRtuthU=
@@ -240,17 +240,17 @@ go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
-golang.org/x/crypto v0.47.0/go.mod h1:ff3Y9VzzKbwSSEzWqJsJVBnWmRwRSHt/6Op5n9bQc4A=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
 golang.org/x/exp v0.0.0-20260112195511-716be5621a96 h1:Z/6YuSHTLOHfNFdb8zVZomZr7cqNgTJvA8+Qz75D8gU=
 golang.org/x/exp v0.0.0-20260112195511-716be5621a96/go.mod h1:nzimsREAkjBCIEFtHiYkrJyT+2uy9YZJB7H1k68CXZU=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
-golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
+golang.org/x/net v0.51.0 h1:94R/GTO7mt3/4wIKpcR5gkGmRLOuE/2hNGeWq/GBIFo=
+golang.org/x/net v0.51.0/go.mod h1:aamm+2QF5ogm02fjy5Bb7CQ0WMt1/WVM7FtyaTLlA9Y=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -264,18 +264,18 @@ golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
+golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.39.0 h1:RclSuaJf32jOqZz74CkPA9qFuVTX7vhLlpfj/IGWlqY=
-golang.org/x/term v0.39.0/go.mod h1:yxzUCTP/U+FzoxfdKmLaA0RV1WgE0VY7hXBwKtY/4ww=
+golang.org/x/term v0.40.0 h1:36e4zGLqU4yhjlmxEaagx2KuYbJq3EwY8K943ZsHcvg=
+golang.org/x/term v0.40.0/go.mod h1:w2P8uVp06p2iyKKuvXIm7N/y0UCRt3UfJTfZ7oOpglM=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
-golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
+golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
+golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
 golang.org/x/time v0.14.0 h1:MRx4UaLrDotUKUdCIqzPC48t1Y9hANFKIRpNx+Te8PI=
 golang.org/x/time v0.14.0/go.mod h1:eL/Oa2bBBK0TkX57Fyni+NgnyQQN4LitPmob2Hjnqw4=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

cli/src/cmd/exec/commands/mcp.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/azure/azure-dev/cli/azd/pkg/azdext"
 	"github.com/jongio/azd-core/azdextutil"
+	"github.com/jongio/azd-core/keyvault"
 	"github.com/jongio/azd-core/security"
 	"github.com/jongio/azd-core/shellutil"
 	"github.com/jongio/azd-exec/cli/src/internal/version"
@@ -176,7 +177,10 @@ func handleExecScript(ctx context.Context, args azdext.ToolArgs) (*mcp.CallToolR
 
 	cmdArgs := buildShellArgs(shell, validPath, false, scriptArgs)
 	cmd := exec.CommandContext(execCtx, cmdArgs[0], cmdArgs[1:]...)
-	cmd.Env = os.Environ()
+
+	// Resolve Key Vault references in environment variables, matching the
+	// CLI execution path behavior. Continue on error (best-effort).
+	cmd.Env = prepareEnvironmentForMCP(ctx)
 
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -214,7 +218,10 @@ func handleExecInline(ctx context.Context, args azdext.ToolArgs) (*mcp.CallToolR
 
 	cmdArgs := buildShellArgs(shell, command, true, nil)
 	cmd := exec.CommandContext(execCtx, cmdArgs[0], cmdArgs[1:]...)
-	cmd.Env = os.Environ()
+
+	// Resolve Key Vault references in environment variables, matching the
+	// CLI execution path behavior. Continue on error (best-effort).
+	cmd.Env = prepareEnvironmentForMCP(ctx)
 
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -283,8 +290,13 @@ func handleGetEnvironment(_ context.Context, _ azdext.ToolArgs) (*mcp.CallToolRe
 				continue
 			}
 
-			// Exclude known secret-bearing variable names
-			secretPatterns := []string{"SECRET", "PASSWORD", "KEY", "TOKEN", "CREDENTIAL", "CERTIFICATE", "CONNECTION_STRING", "CONNSTR"}
+			// Exclude known secret-bearing variable names.
+			// This denylist covers common Azure, cloud, and application secret patterns.
+			secretPatterns := []string{
+				"SECRET", "PASSWORD", "KEY", "TOKEN", "CREDENTIAL", "CERTIFICATE",
+				"CONNECTION_STRING", "CONNSTR", "PAT", "SAS", "SIGNING",
+				"PRIVATE", "PASSPHRASE", "AUTH",
+			}
 			isSecret := false
 			upperName := strings.ToUpper(name)
 			for _, pattern := range secretPatterns {
@@ -306,6 +318,41 @@ func handleGetEnvironment(_ context.Context, _ azdext.ToolArgs) (*mcp.CallToolRe
 
 // --- Helpers ---
 
+// prepareEnvironmentForMCP resolves Key Vault references in environment variables.
+// This mirrors the CLI execution path (executor.prepareEnvironment) to ensure
+// consistent behavior between CLI and MCP invocations. Operates in best-effort
+// mode: if resolution fails, the original environment is returned unchanged.
+func prepareEnvironmentForMCP(ctx context.Context) []string {
+	envVars := os.Environ()
+
+	// Quick check: skip resolver setup if no Key Vault references are present.
+	hasRef := false
+	for _, envVar := range envVars {
+		if parts := strings.SplitN(envVar, "=", 2); len(parts) == 2 && keyvault.IsKeyVaultReference(parts[1]) {
+			hasRef = true
+			break
+		}
+	}
+	if !hasRef {
+		return envVars
+	}
+
+	resolver, err := keyvault.NewKeyVaultResolver()
+	if err != nil {
+		// Cannot create resolver — fall back to raw environment.
+		fmt.Fprintf(os.Stderr, "Warning: failed to create Key Vault resolver: %v\n", err)
+		return envVars
+	}
+
+	resolved, _, err := resolver.ResolveEnvironmentVariables(ctx, envVars, keyvault.ResolveEnvironmentOptions{StopOnError: false})
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Warning: Key Vault resolution error: %v\n", err)
+		return envVars
+	}
+
+	return resolved
+}
+
 type execResult struct {
 	Stdout   string `json:"stdout"`
 	Stderr   string `json:"stderr"`

cli/src/cmd/exec/commands/version_integration_test.go

@@ -1,5 +1,4 @@
 //go:build integration
-// +build integration
 
 package commands
 

cli/src/cmd/exec/main.go

@@ -33,7 +33,7 @@ type scriptExecutor interface {
 	ExecuteInline(ctx context.Context, scriptContent string) error
 }
 
-var newScriptExecutor = func(config executor.Config) scriptExecutor {
+var newScriptExecutor = func(config executor.Config) (scriptExecutor, error) {
 	return executor.New(config)
 }
 
@@ -75,12 +75,15 @@ Examples:
 		}
 
 		// Create executor
-		exec := newScriptExecutor(executor.Config{
+		exec, err := newScriptExecutor(executor.Config{
 			Shell:               shell,
 			Interactive:         interactive,
 			StopOnKeyVaultError: stopOnKeyVaultError,
 			Args:                scriptArgs,
 		})
+		if err != nil {
+			return fmt.Errorf("invalid configuration: %w", err)
+		}
 
 		// Check if input is a file or inline script
 		// Try to resolve as file path first

cli/src/cmd/exec/main_test.go

@@ -90,9 +90,9 @@ func TestRunE_DispatchesFileOrInline(t *testing.T) {
 	defer func() { newScriptExecutor = oldNew }()
 
 	fake := &fakeExecutor{}
-	newScriptExecutor = func(cfg executor.Config) scriptExecutor {
+	newScriptExecutor = func(cfg executor.Config) (scriptExecutor, error) {
 		fake.args = append([]string{}, cfg.Args...)
-		return fake
+		return fake, nil
 	}
 
 	// Avoid changing env/cwd during Execute.
@@ -150,9 +150,9 @@ func TestRunE_AllowsPassthroughArgsWithoutDoubleDash(t *testing.T) {
 	defer func() { newScriptExecutor = oldNew }()
 
 	fake := &fakeExecutor{}
-	newScriptExecutor = func(cfg executor.Config) scriptExecutor {
+	newScriptExecutor = func(cfg executor.Config) (scriptExecutor, error) {
 		fake.args = append([]string{}, cfg.Args...)
-		return fake
+		return fake, nil
 	}
 
 	// Avoid changing env/cwd during Execute.

cli/src/internal/executor/command_builder.go

@@ -25,32 +25,44 @@ var validShells = map[string]bool{
 //   - Windows cmd: Use /c for both inline and files
 //   - Unknown shells: Fall back to -c flag (Unix-like behavior)
 //
+// Known shell names are normalized to lowercase for the executable binary
+// to ensure correct lookup on case-sensitive filesystems.
 // Script arguments (e.config.Args) are appended after the script specification.
 func (e *Executor) buildCommand(shell, scriptOrPath string, isInline bool) *exec.Cmd {
 	var cmdArgs []string
 	skipAppendArgs := false
 
-	// Normalize shell name to lowercase for comparison
+	// Normalize shell name to lowercase for both comparison and executable name.
+	// This ensures correct binary lookup on case-sensitive filesystems
+	// (e.g., --shell BASH resolves to "bash", not "BASH").
 	shellLower := strings.ToLower(shell)
 
+	// Use the lowercase name for known shells; keep original for unknown shells
+	// (custom interpreters like "Python3" should preserve user's casing).
+	shellBin := shell
+	if validShells[shellLower] {
+		shellBin = shellLower
+	}
+
 	switch shellLower {
 	case shellutil.ShellBash, shellutil.ShellSh, shellutil.ShellZsh:
 		if isInline {
-			cmdArgs = []string{shell, "-c", scriptOrPath}
+			cmdArgs = []string{shellBin, "-c", scriptOrPath}
 		} else {
-			cmdArgs = []string{shell, scriptOrPath}
+			cmdArgs = []string{shellBin, scriptOrPath}
 		}
 	case shellutil.ShellPwsh, shellutil.ShellPowerShell:
 		if isInline {
-			cmdArgs = []string{shell, "-Command", e.buildPowerShellInlineCommand(scriptOrPath)}
+			cmdArgs = []string{shellBin, "-Command", e.buildPowerShellInlineCommand(scriptOrPath)}
 			skipAppendArgs = true
 		} else {
-			cmdArgs = []string{shell, "-File", scriptOrPath}
+			cmdArgs = []string{shellBin, "-File", scriptOrPath}
 		}
 	case shellutil.ShellCmd:
-		cmdArgs = []string{shell, "/c", scriptOrPath}
+		cmdArgs = []string{shellBin, "/c", scriptOrPath}
 	default:
-		// Unknown shell: use Unix-like -c pattern as fallback
+		// Unknown shell: use Unix-like -c pattern as fallback.
+		// Preserve original casing for custom interpreters.
 		if isInline {
 			cmdArgs = []string{shell, "-c", scriptOrPath}
 		} else {

cli/src/internal/executor/command_builder_test.go

@@ -31,7 +31,10 @@ func TestBuildCommandWithCustomShell(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			exec := New(Config{Shell: tt.shell, Args: tt.args})
+			exec, err := New(Config{Args: tt.args})
+			if err != nil {
+				t.Fatalf("New() error: %v", err)
+			}
 			cmd := exec.buildCommand(tt.shell, tt.scriptPath, false)
 
 			// Check if command was built
@@ -75,7 +78,10 @@ func TestBuildCommandShellVariations(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.shell, func(t *testing.T) {
-			exec := New(Config{Shell: tt.shell})
+			exec, err := New(Config{Shell: tt.shell})
+			if err != nil {
+				t.Fatalf("New() error: %v", err)
+			}
 			cmd := exec.buildCommand(tt.shell, tt.scriptPath, false)
 
 			if cmd == nil {
@@ -87,7 +93,10 @@ func TestBuildCommandShellVariations(t *testing.T) {
 
 func TestBuildCommandLookPath(t *testing.T) {
 	// Test that buildCommand creates a valid exec.Cmd
-	exec := New(Config{})
+	exec, err := New(Config{})
+	if err != nil {
+		t.Fatalf("New() error: %v", err)
+	}
 	cmd := exec.buildCommand("cmd", "test.bat", false)
 
 	// On Windows, cmd should be findable
@@ -96,7 +105,7 @@ func TestBuildCommandLookPath(t *testing.T) {
 	}
 
 	// Verify we can look up the command
-	_, err := execLookPath(cmd.Args[0])
+	_, err = execLookPath(cmd.Args[0])
 	if err != nil {
 		t.Logf("Command %v not found in PATH (may be platform-specific)", cmd.Args[0])
 	}
@@ -133,15 +142,21 @@ func TestQuotePowerShellArg(t *testing.T) {
 
 func TestBuildPowerShellInlineCommand(t *testing.T) {
 	t.Run("no args returns script as-is", func(t *testing.T) {
-		e := New(Config{})
+		e, err := New(Config{})
+		if err != nil {
+			t.Fatalf("New() error: %v", err)
+		}
 		got := e.buildPowerShellInlineCommand("Get-Date")
 		if got != "Get-Date" {
 			t.Errorf("got %q, want %q", got, "Get-Date")
 		}
 	})
 
 	t.Run("with args joins and quotes", func(t *testing.T) {
-		e := New(Config{Args: []string{"arg1", "it's"}})
+		e, err := New(Config{Args: []string{"arg1", "it's"}})
+		if err != nil {
+			t.Fatalf("New() error: %v", err)
+		}
 		got := e.buildPowerShellInlineCommand("cmd")
 		want := "cmd 'arg1' 'it''s'"
 		if got != want {