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Optimizes private key normalization #4224

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d482536
refactor: optimize private key normalization with single-pass replace…
ahrav Jun 13, 2025
cb33629
rename param
ahrav Jun 13, 2025
e091a21
inline if check
ahrav Jun 13, 2025
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ahrav Jun 13, 2025
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84 changes: 61 additions & 23 deletions pkg/detectors/privatekey/normalize.go
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Original file line number Diff line number Diff line change
Expand Up @@ -4,28 +4,66 @@ import (
"strings"
)

func Normalize(in string) string {
in = strings.ReplaceAll(in, `"`, "")
in = strings.ReplaceAll(in, `'`, "")
in = strings.ReplaceAll(in, "\t", "")
in = strings.ReplaceAll(in, `\t`, "")
in = strings.ReplaceAll(in, `\\t`, "")
in = strings.ReplaceAll(in, `\n`, "\n")
in = strings.ReplaceAll(in, `\\r\\n`, "\n")
in = strings.ReplaceAll(in, `\r\n`, "\n")
in = strings.ReplaceAll(in, "\r\n", "\n")
in = strings.ReplaceAll(in, `\\r`, "\n")
in = strings.ReplaceAll(in, "\r", "\n")
in = strings.ReplaceAll(in, `\r`, "\n")
in = strings.ReplaceAll(in, `\\n`, "\n")
in = strings.ReplaceAll(in, `\n\n`, "\n")
in = strings.ReplaceAll(in, "\n\n", "\n")
in = strings.ReplaceAll(in, `\\`, "\n")

cleaned := strings.Builder{}
parts := strings.Split(in, "\n")
for _, line := range parts {
cleaned.WriteString(strings.TrimSpace(line) + "\n")
// escapeReplacer converts a variety of platform‐specific and escaped
// whitespace sequences into a canonical representation.
// The order of the patterns matters: the double-escaped forms (e.g. "\\n")
// must be replaced before the single-escaped forms ("\n") so that each
// sequence is handled exactly once.
var escapeReplacer = strings.NewReplacer(
`\\n`, "\n", // Double-escaped newlines
`\n`, "\n", // Single-escaped newlines
`\\r\\n`, "\n", // Double-escaped CRLF
`\r\n`, "\n", // Escaped CRLF
"\r\n", "\n", // Actual CRLF
`\\r`, "\n", // Double-escaped CR
`\r`, "\n", // Escaped CR
"\r", "\n", // Actual CR
`\\t`, "", // Double-escaped tabs
`\t`, "", // Escaped tabs
"\t", "", // Actual tabs
)

// Normalize prepares a raw private-key string for parsing.
//
// Normalize applies a best-effort cleanup so that keys copied from environment
// variables, JSON blobs, or other text formats are converted into a form that
// Go's crypto/x509 and crypto/ssh parsers can consume reliably. It performs the
// following steps:
//
// 1. Trim leading and trailing whitespace.
// 2. Remove a single layer of surrounding single or double quotes.
// 3. Replace escaped or platform-specific newline/carriage-return/tab
// sequences with a canonical "\n", removing tabs entirely.
// 4. Split the text on "\n", trim each line, drop empty lines, and rejoin
// the remainder with a trailing newline.
//
// The function never returns an error; if "in" is already well-formed, it is
// returned unchanged (apart from guaranteeing a trailing newline).
func Normalize(raw string) string {
raw = strings.TrimSpace(raw)

// Remove surrounding quotes if present.
if len(raw) >= 2 {
if (raw[0] == '"' && raw[len(raw)-1] == '"') ||
(raw[0] == '\'' && raw[len(raw)-1] == '\'') {
raw = raw[1 : len(raw)-1]
}
}

// Canonicalize escape sequences in one pass.
raw = escapeReplacer.Replace(raw)

var result strings.Builder
result.Grow(len(raw))

// Normalize per-line whitespace and discard blank lines.
lines := strings.Split(raw, "\n")
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I can see how memory usage decreases by minimizing allocations because they have overhead, but I would guess a bigger source of memory usage is building a new array of the whole string here. If you change this loop to use strings.Find to iterate through the string line by line you can probably halve memory usage. It's more tedious and harder to read, but such is the nature of optimizing I guess.

for _, line := range lines {
if trimmed := strings.TrimSpace(line); trimmed != "" {
result.WriteString(trimmed)
result.WriteByte('\n')
}
}
return cleaned.String()

return result.String()
}
100 changes: 100 additions & 0 deletions pkg/detectors/privatekey/normalize_test.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,100 @@
package privatekey

import (
"strings"
"testing"

"github.com/stretchr/testify/assert"
)

func TestNormalize(t *testing.T) {
tests := []struct {
name string
input string
expected string
}{
{
name: "quoted_rsa_private_key",
input: `"-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END RSA PRIVATE KEY-----"`,
expected: "-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END RSA PRIVATE KEY-----\n",
},
{
name: "escaped_newlines_private_key",
input: "-----BEGIN PRIVATE KEY-----\\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC7VJTUt9Us8cKB\\nUkJJKHhHVXvmLOHEaYKXlLFyFGZfJTZWlbNJOkYGKhLBBsGgVJGWZJGKzKwJ7c\\n-----END PRIVATE KEY-----",
expected: "-----BEGIN PRIVATE KEY-----\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC7VJTUt9Us8cKB\nUkJJKHhHVXvmLOHEaYKXlLFyFGZfJTZWlbNJOkYGKhLBBsGgVJGWZJGKzKwJ7c\n-----END PRIVATE KEY-----\n",
},
{
name: "windows_crlf_private_key",
input: "-----BEGIN RSA PRIVATE KEY-----\r\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\r\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\r\n-----END RSA PRIVATE KEY-----",
expected: "-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END RSA PRIVATE KEY-----\n",
},
{
name: "tabs_and_quotes_private_key",
input: `"-----BEGIN PRIVATE KEY-----\t\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC7VJTUt9Us8cKB\t\nUkJJKHhHVXvmLOHEaYKXlLFyFGZfJTZWlbNJOkYGKhLBBsGgVJGWZJGKzKwJ7c\t\n-----END PRIVATE KEY-----"`,
expected: "-----BEGIN PRIVATE KEY-----\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC7VJTUt9Us8cKB\nUkJJKHhHVXvmLOHEaYKXlLFyFGZfJTZWlbNJOkYGKhLBBsGgVJGWZJGKzKwJ7c\n-----END PRIVATE KEY-----\n",
},
{
name: "double_escaped_newlines",
input: "-----BEGIN RSA PRIVATE KEY-----\\\\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\\\\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\\\\n-----END RSA PRIVATE KEY-----",
expected: "-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END RSA PRIVATE KEY-----\n",
},
{
name: "ec_private_key_with_mixed_formatting",
input: `'-----BEGIN EC PRIVATE KEY-----\nMHcCAQEEIK8X2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1ZoAoGCCqGSM49\nAwEHoUQDQgAE7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END EC PRIVATE KEY-----'`,
expected: "-----BEGIN EC PRIVATE KEY-----\nMHcCAQEEIK8X2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1ZoAoGCCqGSM49\nAwEHoUQDQgAE7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END EC PRIVATE KEY-----\n",
},
{
name: "openssh_private_key_with_spaces",
input: ` "-----BEGIN OPENSSH PRIVATE KEY-----\nb3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAFwAAAAdzc2gtcn\nNhAAAAAwEAAQAAAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END OPENSSH PRIVATE KEY-----" `,
expected: "-----BEGIN OPENSSH PRIVATE KEY-----\nb3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAFwAAAAdzc2gtcn\nNhAAAAAwEAAQAAAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END OPENSSH PRIVATE KEY-----\n",
},
}

for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
assert.Equal(t, tc.expected, Normalize(tc.input))
})
}
}

func BenchmarkNormalize(b *testing.B) {
testCases := []struct {
name string
input string
}{
{
name: "quoted_rsa_key",
input: `"-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END RSA PRIVATE KEY-----"`,
},
{
name: "escaped_newlines_key",
input: "-----BEGIN PRIVATE KEY-----\\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC7VJTUt9Us8cKB\\nUkJJKHhHVXvmLOHEaYKXlLFyFGZfJTZWlbNJOkYGKhLBBsGgVJGWZJGKzKwJ7c\\n-----END PRIVATE KEY-----",
},
{
name: "windows_crlf_key",
input: "-----BEGIN RSA PRIVATE KEY-----\r\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\r\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\r\n-----END RSA PRIVATE KEY-----",
},
{
name: "large_key_with_mixed_formatting",
input: strings.Repeat(`"-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\n-----END RSA PRIVATE KEY-----"\n`, 10),
},
{
name: "ec_key_with_tabs_and_quotes",
input: `'-----BEGIN EC PRIVATE KEY-----\t\nMHcCAQEEIK8X2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1ZoAoGCCqGSM49\t\nAwEHoUQDQgAE7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\t\n-----END EC PRIVATE KEY-----'`,
},
{
name: "openssh_key_double_escaped",
input: "-----BEGIN OPENSSH PRIVATE KEY-----\\\\nb3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAFwAAAAdzc2gtcn\\\\nNhAAAAAwEAAQAAAQEA7Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z2Z1Z\\\\n-----END OPENSSH PRIVATE KEY-----",
},
}

for _, tc := range testCases {
b.Run(tc.name, func(b *testing.B) {
b.ReportAllocs()
b.SetBytes(int64(len(tc.input)))
for i := 0; i < b.N; i++ {
_ = Normalize(tc.input)
}
})
}
}
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