Add support for PKCS#11 token key management

Author: beurdouche

bindings/bindings.toml

@@ -138,6 +138,9 @@ types = [
     "HpkeAeadId",
     "HpkeKdfId",
     "HpkeKemId",
+    "PK11AttrFlags",
+    "PK11SlotListStr",
+    "PK11SlotListElementStr",
     "PK11SymKeyStr",
     "SECKEYPrivateKeyStr",
 ]
@@ -147,6 +150,7 @@ functions = [
     "CERT_GetCertificateDer",
     "NSS_SetAlgorithmPolicy",
     "PK11_AEADOp",
+    "PK11_Authenticate",
     "PK11_CipherOp",
     "PK11_CreateContextBySymKey",
     "PK11_Decrypt",
@@ -160,14 +164,20 @@ functions = [
     "PK11_FindCertFromNickname",
     "PK11_FindKeyByAnyCert",
     "PK11_FreeSlot",
+    "PK11_FreeSlotList",
     "PK11_FreeSymKey",
     "PK11_GenerateKeyPairWithOpFlags",
+    "PK11_GetNextSymKey",
+    "PK11_GetSymKeyNickname",
     "PK11_GenerateKeyPair",
     "PK11_GenerateRandom",
+    "PK11_GetAllTokens",
     "PK11_GetBlockSize",
+    "PK11_GetInternalKeySlot",
     "PK11_GetInternalSlot",
     "PK11_GetKeyData",
     "PK11_GetMechanism",
+    "PK11_GetTokenName",
     "PK11_HashBuf",
     "PK11_HPKE_Deserialize",
     "PK11_HPKE_ExportSecret",
@@ -184,10 +194,14 @@ functions = [
     "PK11_ImportDERPrivateKeyInfoAndReturnKey",
     "PK11_ImportPublicKey",
     "PK11_ImportSymKey",
+    "PK11_ListFixedKeysInSlot",
     "PK11_PubDeriveWithKDF",
     "PK11_ReadRawAttribute",
+    "PK11_ReferenceSlot",
     "PK11_ReferenceSymKey",
+    "PK11_SetSymKeyNickname",
     "PK11_SignWithMechanism",
+    "PK11_TokenKeyGenWithFlags",
     "PK11_VerifyWithMechanism",
     "PK11_WrapPrivKey",
     "SECITEM_AllocItem",
@@ -217,6 +231,7 @@ variables = [
     "NSS_USE_ALG_IN_SSL_KX",
     "PK11_ATTR_INSENSITIVE",
     "PK11_ATTR_PRIVATE",
+    "PK11_ATTR_TOKEN",
     "PK11_ATTR_PUBLIC",
     "PK11_ATTR_SENSITIVE",
     "PK11_ATTR_SESSION",
@@ -236,7 +251,9 @@ variables = [
     "CKG_NO_GENERATE",
     "CKM_AES_GCM",
     "CKM_CHACHA20_POLY1305",
+    "CKF_DECRYPT",
     "CKF_DERIVE",
+    "CKF_ENCRYPT",
     "CKM_EC_KEY_PAIR_GEN",
     "CK_INVALID_HANDLE",
     "CKF_HKDF_SALT_NULL",
@@ -249,6 +266,7 @@ variables = [
     "CKM_SHA256_HMAC",
     "CKM_SHA384_HMAC",
     "CKM_SHA512_HMAC",
+    "CKM_AES_KEY_GEN",
     "CKM_ECDSA",
     "CKM_EDDSA",
 ]

src/lib.rs

@@ -28,6 +28,7 @@ pub mod ec;
 pub mod hash;
 pub mod hmac;
 pub mod p11;
+pub mod pk11_utils;
 mod prio;
 mod replay;
 mod secrets;

src/p11.rs

@@ -15,7 +15,7 @@ use std::{
     cell::RefCell,
     convert::TryFrom as _,
     fmt::{self, Debug, Formatter},
-    os::raw::c_uint,
+    os::raw::{c_int, c_uint},
     ptr::null_mut,
 };
 
@@ -174,6 +174,103 @@ impl Slot {
     pub fn internal() -> Res<Self> {
         unsafe { Self::from_ptr(PK11_GetInternalSlot()) }
     }
+
+    pub fn internal_key_slot() -> Res<Self> {
+        unsafe { Self::from_ptr(PK11_GetInternalKeySlot()) }
+    }
+
+    pub fn token_name(&self) -> String {
+        let name = unsafe { PK11_GetTokenName(self.ptr) };
+        if name.is_null() {
+            return String::new();
+        }
+        unsafe { std::ffi::CStr::from_ptr(name) }
+            .to_string_lossy()
+            .into_owned()
+    }
+
+    pub fn authenticate(&self) -> Res<()> {
+        secstatus_to_res(unsafe {
+            PK11_Authenticate(self.ptr, PRBool::from(true), null_mut())
+        })
+    }
+
+    /// Find a persistent symmetric key on this slot by nickname.
+    /// Returns `None` if no key with the given nickname exists.
+    pub fn find_key_by_nickname(&self, nickname: &str) -> Option<SymKey> {
+        let c_nickname =
+            std::ffi::CString::new(nickname).ok()?;
+        let ptr = unsafe {
+            PK11_ListFixedKeysInSlot(
+                self.ptr,
+                c_nickname.as_ptr() as *mut _,
+                null_mut(),
+            )
+        };
+        if ptr.is_null() {
+            None
+        } else {
+            SymKey::from_ptr(ptr).ok()
+        }
+    }
+
+    /// Generate a persistent symmetric key on this slot with a nickname.
+    pub fn generate_token_key(
+        &self,
+        mechanism: CK_MECHANISM_TYPE,
+        key_size: usize,
+        nickname: &str,
+    ) -> Res<SymKey> {
+        let key = unsafe {
+            SymKey::from_ptr(PK11_TokenKeyGenWithFlags(
+                self.ptr,
+                mechanism,
+                null_mut(),
+                c_int::try_from(key_size).map_err(|_| Error::IntegerOverflow)?,
+                null_mut(),
+                CK_FLAGS::from(CKF_ENCRYPT | CKF_DECRYPT),
+                PK11AttrFlags::from(PK11_ATTR_TOKEN | PK11_ATTR_PRIVATE | PK11_ATTR_SENSITIVE),
+                null_mut(),
+            ))
+        }?;
+        let c_nickname =
+            std::ffi::CString::new(nickname).map_err(|_| Error::InvalidInput)?;
+        secstatus_to_res(unsafe {
+            PK11_SetSymKeyNickname(*key, c_nickname.as_ptr())
+        })?;
+        Ok(key)
+    }
+}
+
+/// Returns all available token slots for the given mechanism.
+pub fn all_token_slots(mechanism: CK_MECHANISM_TYPE) -> Res<Vec<Slot>> {
+    let list = unsafe {
+        PK11_GetAllTokens(
+            mechanism,
+            PRBool::from(false),
+            PRBool::from(false),
+            null_mut(),
+        )
+    };
+    if list.is_null() {
+        return Ok(Vec::new());
+    }
+    let mut result = Vec::new();
+    unsafe {
+        let mut elem = (*list).head;
+        while !elem.is_null() {
+            let slot_ptr = (*elem).slot;
+            if !slot_ptr.is_null() {
+                PK11_ReferenceSlot(slot_ptr);
+                if let Ok(slot) = Slot::from_ptr(slot_ptr) {
+                    result.push(slot);
+                }
+            }
+            elem = (*elem).next;
+        }
+        PK11_FreeSlotList(list);
+    }
+    Ok(result)
 }
 
 // Note: PK11SymKey is internally reference counted
@@ -249,7 +346,7 @@ pub fn randomize<B: AsMut<[u8]>>(mut buf: B) -> B {
 #[cfg(not(feature = "disable-random"))]
 pub fn randomize<B: AsMut<[u8]>>(mut buf: B) -> B {
     let m_buf = buf.as_mut();
-    let len = std::os::raw::c_int::try_from(m_buf.len()).expect("usize fits into c_int");
+    let len = c_int::try_from(m_buf.len()).expect("usize fits into c_int");
     secstatus_to_res(unsafe { PK11_GenerateRandom(m_buf.as_mut_ptr(), len) }).expect("NSS failed");
     buf
 }

src/pk11_utils.rs

@@ -0,0 +1,123 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use crate::err::{Error, Res};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Pkcs11Uri {
+    pub token: Option<String>,
+}
+
+fn percent_decode(s: &str) -> String {
+    let mut result = Vec::with_capacity(s.len());
+    let bytes = s.as_bytes();
+    let mut i = 0;
+    while i < bytes.len() {
+        if bytes[i] == b'%' && i + 2 < bytes.len() {
+            if let Ok(byte) = u8::from_str_radix(
+                std::str::from_utf8(&bytes[i + 1..i + 3]).unwrap_or(""),
+                16,
+            ) {
+                result.push(byte);
+                i += 3;
+                continue;
+            }
+        }
+        result.push(bytes[i]);
+        i += 1;
+    }
+    String::from_utf8_lossy(&result).into_owned()
+}
+
+fn percent_encode(s: &str) -> String {
+    let mut result = String::with_capacity(s.len());
+    for b in s.bytes() {
+        match b {
+            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'.' | b'_' | b'~' => {
+                result.push(b as char);
+            }
+            _ => {
+                result.push_str(&format!("%{:02X}", b));
+            }
+        }
+    }
+    result
+}
+
+/// Parse a PKCS#11 URI (RFC 7512).
+/// Expects the input to start with "pkcs11:".
+pub fn parse(uri: &str) -> Res<Pkcs11Uri> {
+    let path = uri
+        .strip_prefix("pkcs11:")
+        .ok_or(Error::InvalidInput)?;
+
+    let mut token = None;
+    for attr in path.split(';') {
+        if let Some((key, value)) = attr.split_once('=') {
+            if key == "token" {
+                token = Some(percent_decode(value));
+            }
+        }
+    }
+
+    Ok(Pkcs11Uri { token })
+}
+
+/// Build a PKCS#11 URI from a token name.
+pub fn build(token_name: &str) -> String {
+    format!("pkcs11:token={}", percent_encode(token_name))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test_fixture::fixture_init;
+
+    #[test]
+    fn parse_simple() {
+        fixture_init();
+        let uri = parse("pkcs11:token=NSS%20Certificate%20DB").unwrap();
+        assert_eq!(uri.token.as_deref(), Some("NSS Certificate DB"));
+    }
+
+    #[test]
+    fn parse_no_token() {
+        fixture_init();
+        let uri = parse("pkcs11:manufacturer=Mozilla").unwrap();
+        assert_eq!(uri.token, None);
+    }
+
+    #[test]
+    fn parse_multiple_attrs() {
+        fixture_init();
+        let uri = parse("pkcs11:token=MyToken;manufacturer=Test;serial=1234").unwrap();
+        assert_eq!(uri.token.as_deref(), Some("MyToken"));
+    }
+
+    #[test]
+    fn parse_not_pkcs11() {
+        fixture_init();
+        assert!(parse("http://example.com").is_err());
+    }
+
+    #[test]
+    fn build_uri() {
+        fixture_init();
+        assert_eq!(
+            build("NSS Certificate DB"),
+            "pkcs11:token=NSS%20Certificate%20DB"
+        );
+    }
+
+    #[test]
+    fn roundtrip() {
+        fixture_init();
+        let name = "My Token (Test-v2)";
+        let uri_str = build(name);
+        let parsed = parse(&uri_str).unwrap();
+        assert_eq!(parsed.token.as_deref(), Some(name));
+    }
+}