docs: drop RFC citations and what-comments, fix stale refs

Apply the no-internal-citation and WHY-not-WHAT rules to source
comments; correct stale identifiers (NewBrowser, PBKDF2Key) and RFC
facts (Yandex ciphertext, Firefox PBKDF2 password).

crypto/asn1pbe.go

@@ -98,7 +98,7 @@ func (n privateKeyPBE) deriveKeyAndIV(globalSalt []byte) ([]byte, []byte) {
 	return dk[:24], dk[len(dk)-8:]
 }
 
-// MetaPBE Struct
+// passwordCheckPBE Struct
 //
 //	SEQUENCE (2 elem)
 //		OBJECT IDENTIFIER

crypto/crypto.go

@@ -137,7 +137,6 @@ func AESGCMDecryptBlob(key, blob, aad []byte) ([]byte, error) {
 	return aead.Open(nil, blob[:gcmNonceSize], blob[gcmNonceSize:], aad)
 }
 
-// cbcEncrypt adds PKCS5 padding and encrypts plaintext in CBC mode.
 func cbcEncrypt(block cipher.Block, iv, plaintext []byte) ([]byte, error) {
 	if len(iv) != block.BlockSize() {
 		return nil, errInvalidIVLength
@@ -149,7 +148,6 @@ func cbcEncrypt(block cipher.Block, iv, plaintext []byte) ([]byte, error) {
 	return dst, nil
 }
 
-// cbcDecrypt decrypts ciphertext in CBC mode and removes PKCS5 padding.
 func cbcDecrypt(block cipher.Block, iv, ciphertext []byte) ([]byte, error) {
 	bs := block.BlockSize()
 	if len(iv) != bs {
@@ -172,8 +170,7 @@ func cbcDecrypt(block cipher.Block, iv, ciphertext []byte) ([]byte, error) {
 	return dst, nil
 }
 
-// paddingZero pads src with zero bytes to the given length.
-// Returns src unchanged if already long enough; otherwise returns a new slice.
+// paddingZero returns src unchanged if already long enough; otherwise a zero-padded new slice.
 func paddingZero(src []byte, length int) []byte {
 	if len(src) >= length {
 		return src
@@ -195,7 +192,6 @@ func pkcs5Padding(src []byte, blockSize int) []byte {
 	return dst
 }
 
-// pkcs5UnPadding removes PKCS5/PKCS7 padding from src.
 func pkcs5UnPadding(src []byte, blockSize int) ([]byte, error) {
 	length := len(src)
 	if length == 0 {

crypto/pbkdf2.go

@@ -14,7 +14,7 @@ import (
 // can get a derived key for e.g. AES-256 (which needs a 32-byte key) by
 // doing:
 //
-//	dk := pbkdf2.Key([]byte("some password"), salt, 4096, 32, sha1.New)
+//	dk := PBKDF2Key([]byte("some password"), salt, 4096, 32, sha1.New)
 //
 // Remember to get a good random salt. At least 8 bytes is recommended by the
 // RFC.

crypto/version.go

@@ -23,7 +23,6 @@ const (
 	// CipherDPAPI is pre-Chrome 80 raw DPAPI encryption (no version prefix).
 	CipherDPAPI CipherVersion = "dpapi"
 
-	// versionPrefixLen is the byte length of the version prefix ("v10", "v20").
 	versionPrefixLen = 3
 )
 
@@ -47,8 +46,6 @@ func DetectVersion(ciphertext []byte) CipherVersion {
 	}
 }
 
-// stripPrefix removes the version prefix (e.g. "v10") from ciphertext.
-// Returns the ciphertext unchanged if no known prefix is found.
 func stripPrefix(ciphertext []byte) []byte {
 	ver := DetectVersion(ciphertext)
 	if ver == CipherV10 || ver == CipherV11 || ver == CipherV12 || ver == CipherV20 {

crypto/windows/abe_native/bootstrap_layout.h

@@ -5,7 +5,8 @@
 #include <stddef.h>
 
 // BootstrapScratch describes the IPC contract between the C payload running
-// inside chrome.exe and the Go injector in our own process. It squats inside
+// inside the target browser process (chrome.exe, msedge.exe, brave.exe, etc.)
+// and the Go injector in our own process. It squats inside
 // the target DLL's PE DOS header region. Windows' PE loader ignores the DOS
 // stub at 0x40..0x77, and we also borrow a few reserved bytes between 0x28
 // and 0x3B inside IMAGE_DOS_HEADER. The e_lfanew at 0x3C..0x3F MUST be left

crypto/yandex.go

@@ -22,7 +22,7 @@ var (
 	errYandexKeyTooShort    = errors.New("yandex: decrypted intermediate key shorter than 32 bytes")
 )
 
-// DecryptYandexIntermediateKey unwraps the per-DB data key from meta.local_encryptor_data. See RFC-012 §4.2.
+// DecryptYandexIntermediateKey unwraps the per-DB data key from meta.local_encryptor_data.
 func DecryptYandexIntermediateKey(masterKey, blob []byte) ([]byte, error) {
 	idx := bytes.Index(blob, localEncryptorPrefix)
 	if idx < 0 {