Commit c0bcf6fb authored by Steven Fackler's avatar Steven Fackler
Browse files

Merge pull request #229 from jmesmon/alpn

Add support for ALPN ("successor" to NPN)
parents 6e43f5c0 01e01e37
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+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ dtlsv1_2 = []
sslv2 = []
aes_xts = []
npn = []
alpn = []

[dependencies]
libc = "0.1"
+19 −1
Original line number Diff line number Diff line
@@ -547,13 +547,31 @@ extern "C" {
                                                              inlen: c_uint,
                                                              arg: *mut c_void) -> c_int,
                                            arg: *mut c_void);
    #[cfg(feature = "npn")]
    #[cfg(any(feature = "alpn", feature = "npn"))]
    pub fn SSL_select_next_proto(out: *mut *mut c_uchar, outlen: *mut c_uchar,
                                 inbuf: *const c_uchar, inlen: c_uint,
                                 client: *const c_uchar, client_len: c_uint) -> c_int;
    #[cfg(feature = "npn")]
    pub fn SSL_get0_next_proto_negotiated(s: *const SSL, data: *mut *const c_uchar, len: *mut c_uint);

    #[cfg(feature = "alpn")]
    pub fn SSL_CTX_set_alpn_protos(s: *mut SSL_CTX, data: *const c_uchar, len: c_uint) -> c_int;

    #[cfg(feature = "alpn")]
    pub fn SSL_set_alpn_protos(s: *mut SSL, data: *const c_uchar, len: c_uint) -> c_int;

    #[cfg(feature = "alpn")]
    pub fn SSL_CTX_set_alpn_select_cb(ssl: *mut SSL_CTX,
                                            cb: extern "C" fn(ssl: *mut SSL,
                                                              out: *mut *mut c_uchar,
                                                              outlen: *mut c_uchar,
                                                              inbuf: *const c_uchar,
                                                              inlen: c_uint,
                                                              arg: *mut c_void) -> c_int,
                                            arg: *mut c_void);
    #[cfg(feature = "alpn")]
    pub fn SSL_get0_alpn_selected(s: *const SSL, data: *mut *const c_uchar, len: *mut c_uint);

    pub fn X509_add_ext(x: *mut X509, ext: *mut X509_EXTENSION, loc: c_int) -> c_int;
    pub fn X509_digest(x: *mut X509, digest: *const EVP_MD, buf: *mut c_char, len: *mut c_uint) -> c_int;
    pub fn X509_free(x: *mut X509);
+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ dtlsv1_2 = ["openssl-sys/dtlsv1_2"]
sslv2 = ["openssl-sys/sslv2"]
aes_xts = ["openssl-sys/aes_xts"]
npn = ["openssl-sys/npn"]
alpn = ["openssl-sys/alpn"]

[dependencies.openssl-sys]
path = "../openssl-sys"
+134 −54
Original line number Diff line number Diff line
@@ -13,9 +13,9 @@ use std::sync::{Once, ONCE_INIT, Arc, Mutex};
use std::ops::{Deref, DerefMut};
use std::cmp;
use std::any::Any;
#[cfg(feature = "npn")]
#[cfg(any(feature = "npn", feature = "alpn"))]
use libc::{c_uchar, c_uint};
#[cfg(feature = "npn")]
#[cfg(any(feature = "npn", feature = "alpn"))]
use std::slice;

use bio::{MemBio};
@@ -170,49 +170,37 @@ lazy_static! {
// Registers a destructor for the data which will be called
// when context is freed
fn get_verify_data_idx<T: Any + 'static>() -> c_int {
    extern fn free_data_box<T>(_parent: *mut c_void, ptr: *mut c_void,
                               _ad: *mut ffi::CRYPTO_EX_DATA, _idx: c_int,
                               _argl: c_long, _argp: *mut c_void) {
        if ptr != 0 as *mut _ {
            let _: Box<T> = unsafe { mem::transmute(ptr) };
        }
    }

    *INDEXES.lock().unwrap().entry(TypeId::of::<T>()).or_insert_with(|| {
        unsafe {
            let f: ffi::CRYPTO_EX_free = free_data_box::<T>;
            let idx = ffi::SSL_CTX_get_ex_new_index(0, ptr::null(), None, None, Some(f));
            assert!(idx >= 0);
            idx
        }
        get_new_idx::<T>()
    })
}

/// Creates a static index for the list of NPN protocols.
/// Registers a destructor for the data which will be called
/// when the context is freed.
#[cfg(feature = "npn")]
fn get_npn_protos_idx() -> c_int {
    static mut NPN_PROTOS_IDX: c_int = -1;
    static mut INIT: Once = ONCE_INIT;
lazy_static! {
    static ref NPN_PROTOS_IDX: c_int = get_new_idx::<Vec<u8>>();
}
#[cfg(feature = "alpn")]
lazy_static! {
    static ref ALPN_PROTOS_IDX: c_int = get_new_idx::<Vec<u8>>();
}

    extern fn free_data_box(_parent: *mut c_void, ptr: *mut c_void,
/// Determine a new index to use for SSL CTX ex data.
/// Registers a destruct for the data which will be called by openssl when the context is freed.
fn get_new_idx<T>() -> c_int {
    extern fn free_data_box<T>(_parent: *mut c_void, ptr: *mut c_void,
                            _ad: *mut ffi::CRYPTO_EX_DATA, _idx: c_int,
                            _argl: c_long, _argp: *mut c_void) {
        if !ptr.is_null() {
            let _: Box<Vec<u8>> = unsafe { mem::transmute(ptr) };
            let _: Box<T> = unsafe { mem::transmute(ptr) };
        }
    }

    unsafe {
        INIT.call_once(|| {
            let f: ffi::CRYPTO_EX_free = free_data_box;
        let f: ffi::CRYPTO_EX_free = free_data_box::<T>;
        let idx = ffi::SSL_CTX_get_ex_new_index(0, ptr::null(), None,
                                                None, Some(f));
        assert!(idx >= 0);
            NPN_PROTOS_IDX = idx;
        });
        NPN_PROTOS_IDX
        idx
    }
}

@@ -264,22 +252,16 @@ extern fn raw_verify_with_data<T>(preverify_ok: c_int,
    }
}

/// The function is given as the callback to `SSL_CTX_set_next_proto_select_cb`.
///
/// It chooses the protocol that the client wishes to use, out of the given list of protocols
/// supported by the server. It achieves this by delegating to the `SSL_select_next_proto`
/// function. The list of protocols supported by the client is found in the extra data of the
/// OpenSSL context.
#[cfg(feature = "npn")]
extern fn raw_next_proto_select_cb(ssl: *mut ffi::SSL,
#[cfg(any(feature = "npn", feature = "alpn"))]
unsafe fn select_proto_using(ssl: *mut ffi::SSL,
                      out: *mut *mut c_uchar, outlen: *mut c_uchar,
                      inbuf: *const c_uchar, inlen: c_uint,
                                   _arg: *mut c_void) -> c_int {
    unsafe {
                      ex_data: c_int) -> c_int {

        // First, get the list of protocols (that the client should support) saved in the context
        // extra data.
        let ssl_ctx = ffi::SSL_get_SSL_CTX(ssl);
        let protocols = ffi::SSL_CTX_get_ex_data(ssl_ctx, get_npn_protos_idx());
        let protocols = ffi::SSL_CTX_get_ex_data(ssl_ctx, ex_data);
        let protocols: &Vec<u8> = mem::transmute(protocols);
        // Prepare the client list parameters to be passed to the OpenSSL function...
        let client = protocols.as_ptr();
@@ -287,9 +269,33 @@ extern fn raw_next_proto_select_cb(ssl: *mut ffi::SSL,
        // Finally, let OpenSSL find a protocol to be used, by matching the given server and
        // client lists.
        ffi::SSL_select_next_proto(out, outlen, inbuf, inlen, client, client_len);
        ffi::SSL_TLSEXT_ERR_OK
}

    ffi::SSL_TLSEXT_ERR_OK
/// The function is given as the callback to `SSL_CTX_set_next_proto_select_cb`.
///
/// It chooses the protocol that the client wishes to use, out of the given list of protocols
/// supported by the server. It achieves this by delegating to the `SSL_select_next_proto`
/// function. The list of protocols supported by the client is found in the extra data of the
/// OpenSSL context.
#[cfg(feature = "npn")]
extern fn raw_next_proto_select_cb(ssl: *mut ffi::SSL,
                                   out: *mut *mut c_uchar, outlen: *mut c_uchar,
                                   inbuf: *const c_uchar, inlen: c_uint,
                                   _arg: *mut c_void) -> c_int {
    unsafe {
        select_proto_using(ssl, out, outlen, inbuf, inlen, *NPN_PROTOS_IDX)
    }
}

#[cfg(feature = "alpn")]
extern fn raw_alpn_select_cb(ssl: *mut ffi::SSL,
                                   out: *mut *mut c_uchar, outlen: *mut c_uchar,
                                   inbuf: *const c_uchar, inlen: c_uint,
                                   _arg: *mut c_void) -> c_int {
    unsafe {
        select_proto_using(ssl, out, outlen, inbuf, inlen, *ALPN_PROTOS_IDX)
    }
}

/// The function is given as the callback to `SSL_CTX_set_next_protos_advertised_cb`.
@@ -306,7 +312,7 @@ extern fn raw_next_protos_advertise_cb(ssl: *mut ffi::SSL,
    unsafe {
        // First, get the list of (supported) protocols saved in the context extra data.
        let ssl_ctx = ffi::SSL_get_SSL_CTX(ssl);
        let protocols = ffi::SSL_CTX_get_ex_data(ssl_ctx, get_npn_protos_idx());
        let protocols = ffi::SSL_CTX_get_ex_data(ssl_ctx, *NPN_PROTOS_IDX);
        if protocols.is_null() {
            *out = b"".as_ptr();
            *outlen = 0;
@@ -322,6 +328,24 @@ extern fn raw_next_protos_advertise_cb(ssl: *mut ffi::SSL,
    ffi::SSL_TLSEXT_ERR_OK
}

/// Convert a set of byte slices into a series of byte strings encoded for SSL. Encoding is a byte
/// containing the length followed by the string.
#[cfg(any(feature = "npn", feature = "alpn"))]
fn ssl_encode_byte_strings(strings: &[&[u8]]) -> Vec<u8>
{
    let mut enc = Vec::new();
    for string in strings {
        let len = string.len() as u8;
        if len as usize != string.len() {
            // If the item does not fit, discard it
            continue;
        }
        enc.push(len);
        enc.extend(string[..len as usize].to_vec());
    }
    enc
}

/// The signature of functions that can be used to manually verify certificates
pub type VerifyCallback = fn(preverify_ok: bool,
                             x509_ctx: &X509StoreContext) -> bool;
@@ -531,19 +555,12 @@ impl SslContext {
    pub fn set_npn_protocols(&mut self, protocols: &[&[u8]]) {
        // Firstly, convert the list of protocols to a byte-array that can be passed to OpenSSL
        // APIs -- a list of length-prefixed strings.
        let mut npn_protocols = Vec::new();
        for protocol in protocols {
            let len = protocol.len() as u8;
            npn_protocols.push(len);
            // If the length is greater than the max `u8`, this truncates the protocol name.
            npn_protocols.extend(protocol[..len as usize].to_vec());
        }
        let protocols: Box<Vec<u8>> = Box::new(npn_protocols);
        let protocols: Box<Vec<u8>> = Box::new(ssl_encode_byte_strings(protocols));

        unsafe {
            // Attach the protocol list to the OpenSSL context structure,
            // so that we can refer to it within the callback.
            ffi::SSL_CTX_set_ex_data(self.ctx, get_npn_protos_idx(),
            ffi::SSL_CTX_set_ex_data(self.ctx, *NPN_PROTOS_IDX,
                                     mem::transmute(protocols));
            // Now register the callback that performs the default protocol
            // matching based on the client-supported list of protocols that
@@ -554,6 +571,35 @@ impl SslContext {
            ffi::SSL_CTX_set_next_protos_advertised_cb(self.ctx, raw_next_protos_advertise_cb, ptr::null_mut());
        }
    }

    /// Set the protocols to be used during ALPN (application layer protocol negotiation).
    /// If this is a server, these are the protocols we report to the client.
    /// If this is a client, these are the protocols we try to match with those reported by the
    /// server.
    ///
    /// Note that ordering of the protocols controls the priority with which they are chosen.
    ///
    /// This method needs the `alpn` feature.
    #[cfg(feature = "alpn")]
    pub fn set_alpn_protocols(&mut self, protocols: &[&[u8]]) {
        let protocols: Box<Vec<u8>> = Box::new(ssl_encode_byte_strings(protocols));
        unsafe {
            // Set the context's internal protocol list for use if we are a server
            ffi::SSL_CTX_set_alpn_protos(self.ctx, protocols.as_ptr(), protocols.len() as c_uint);

            // Rather than use the argument to the callback to contain our data, store it in the
            // ssl ctx's ex_data so that we can configure a function to free it later. In the
            // future, it might make sense to pull this into our internal struct Ssl instead of
            // leaning on openssl and using function pointers.
            ffi::SSL_CTX_set_ex_data(self.ctx, *ALPN_PROTOS_IDX,
                                     mem::transmute(protocols));

            // Now register the callback that performs the default protocol
            // matching based on the client-supported list of protocols that
            // has been saved.
            ffi::SSL_CTX_set_alpn_select_cb(self.ctx, raw_alpn_select_cb, ptr::null_mut());
        }
    }
}

#[allow(dead_code)]
@@ -695,6 +741,29 @@ impl Ssl {
        }
    }

    /// Returns the protocol selected by performing ALPN, if any.
    ///
    /// The protocol's name is returned is an opaque sequence of bytes. It is up to the client
    /// to interpret it.
    ///
    /// This method needs the `alpn` feature.
    #[cfg(feature = "alpn")]
    pub fn get_selected_alpn_protocol(&self) -> Option<&[u8]> {
        unsafe {
            let mut data: *const c_uchar = ptr::null();
            let mut len: c_uint = 0;
            // Get the negotiated protocol from the SSL instance.
            // `data` will point at a `c_uchar` array; `len` will contain the length of this array.
            ffi::SSL_get0_alpn_selected(self.ssl, &mut data, &mut len);

            if data.is_null() {
                None
            } else {
                Some(slice::from_raw_parts(data, len as usize))
            }
        }
    }

    /// pending() takes into account only bytes from the TLS/SSL record that is currently being processed (if any).
    pub fn pending(&self) -> usize {
        unsafe {
@@ -1176,6 +1245,17 @@ impl<S: Read+Write> SslStream<S> {
        self.kind.ssl().get_selected_npn_protocol()
    }

    /// Returns the protocol selected by performing ALPN, if any.
    ///
    /// The protocol's name is returned is an opaque sequence of bytes. It is up to the client
    /// to interpret it.
    ///
    /// This method needs the `alpn` feature.
    #[cfg(feature = "alpn")]
    pub fn get_selected_alpn_protocol(&self) -> Option<&[u8]> {
        self.ssl.get_selected_alpn_protocol()
    }

    /// pending() takes into account only bytes from the TLS/SSL record that is currently being processed (if any).
    pub fn pending(&self) -> usize {
        self.kind.ssl().pending()
+113 −0
Original line number Diff line number Diff line
@@ -390,6 +390,28 @@ fn test_pending() {
    assert_eq!(pending, len);
}

/// Tests that connecting with the client using NPN, but the server not does not
/// break the existing connection behavior.
#[test]
#[cfg(feature = "alpn")]
fn test_connect_with_unilateral_alpn() {
    let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
    let mut ctx = SslContext::new(Sslv23).unwrap();
    ctx.set_verify(SSL_VERIFY_PEER, None);
    ctx.set_alpn_protocols(&[b"http/1.1", b"spdy/3.1"]);
    match ctx.set_CA_file(&Path::new("test/cert.pem")) {
        Ok(_) => {}
        Err(err) => panic!("Unexpected error {:?}", err)
    }
    let stream = match SslStream::new(&ctx, stream) {
        Ok(stream) => stream,
        Err(err) => panic!("Expected success, got {:?}", err)
    };
    // Since the socket to which we connected is not configured to use NPN,
    // there should be no selected protocol...
    assert!(stream.get_selected_alpn_protocol().is_none());
}

/// Tests that connecting with the client using NPN, but the server not does not
/// break the existing connection behavior.
#[test]
@@ -412,6 +434,30 @@ fn test_connect_with_unilateral_npn() {
    assert!(stream.get_selected_npn_protocol().is_none());
}

/// Tests that when both the client as well as the server use ALPN and their
/// lists of supported protocols have an overlap, the correct protocol is chosen.
#[test]
#[cfg(feature = "alpn")]
fn test_connect_with_alpn_successful_multiple_matching() {
    // A different port than the other tests: an `openssl` process that has
    // NPN enabled.
    let stream = TcpStream::connect("127.0.0.1:15419").unwrap();
    let mut ctx = SslContext::new(Sslv23).unwrap();
    ctx.set_verify(SSL_VERIFY_PEER, None);
    ctx.set_alpn_protocols(&[b"spdy/3.1", b"http/1.1"]);
    match ctx.set_CA_file(&Path::new("test/cert.pem")) {
        Ok(_) => {}
        Err(err) => panic!("Unexpected error {:?}", err)
    }
    let stream = match SslStream::new(&ctx, stream) {
        Ok(stream) => stream,
        Err(err) => panic!("Expected success, got {:?}", err)
    };
    // The server prefers "http/1.1", so that is chosen, even though the client
    // would prefer "spdy/3.1"
    assert_eq!(b"http/1.1", stream.get_selected_alpn_protocol().unwrap());
}

/// Tests that when both the client as well as the server use NPN and their
/// lists of supported protocols have an overlap, the correct protocol is chosen.
#[test]
@@ -436,6 +482,32 @@ fn test_connect_with_npn_successful_multiple_matching() {
    assert_eq!(b"http/1.1", stream.get_selected_npn_protocol().unwrap());
}

/// Tests that when both the client as well as the server use ALPN and their
/// lists of supported protocols have an overlap -- with only ONE protocol
/// being valid for both.
#[test]
#[cfg(feature = "alpn")]
fn test_connect_with_alpn_successful_single_match() {
    // A different port than the other tests: an `openssl` process that has
    // ALPN enabled.
    let stream = TcpStream::connect("127.0.0.1:15419").unwrap();
    let mut ctx = SslContext::new(Sslv23).unwrap();
    ctx.set_verify(SSL_VERIFY_PEER, None);
    ctx.set_alpn_protocols(&[b"spdy/3.1"]);
    match ctx.set_CA_file(&Path::new("test/cert.pem")) {
        Ok(_) => {}
        Err(err) => panic!("Unexpected error {:?}", err)
    }
    let stream = match SslStream::new(&ctx, stream) {
        Ok(stream) => stream,
        Err(err) => panic!("Expected success, got {:?}", err)
    };
    // The client now only supports one of the server's protocols, so that one
    // is used.
    assert_eq!(b"spdy/3.1", stream.get_selected_alpn_protocol().unwrap());
}


/// Tests that when both the client as well as the server use NPN and their
/// lists of supported protocols have an overlap -- with only ONE protocol
/// being valid for both.
@@ -502,6 +574,47 @@ fn test_npn_server_advertise_multiple() {
    assert_eq!(b"spdy/3.1", stream.get_selected_npn_protocol().unwrap());
}

/// Tests that when the `SslStream` is created as a server stream, the protocols
/// are correctly advertised to the client.
#[test]
#[cfg(feature = "alpn")]
fn test_alpn_server_advertise_multiple() {
    let localhost = "127.0.0.1:15420";
    let listener = TcpListener::bind(localhost).unwrap();
    // We create a different context instance for the server...
    let listener_ctx = {
        let mut ctx = SslContext::new(Sslv23).unwrap();
        ctx.set_verify(SSL_VERIFY_PEER, None);
        ctx.set_alpn_protocols(&[b"http/1.1", b"spdy/3.1"]);
        assert!(ctx.set_certificate_file(
                &Path::new("test/cert.pem"), X509FileType::PEM).is_ok());
        ctx.set_private_key_file(
                &Path::new("test/key.pem"), X509FileType::PEM).unwrap();
        ctx
    };
    // Have the listener wait on the connection in a different thread.
    thread::spawn(move || {
        let (stream, _) = listener.accept().unwrap();
        let _ = SslStream::new_server(&listener_ctx, stream).unwrap();
    });

    let mut ctx = SslContext::new(Sslv23).unwrap();
    ctx.set_verify(SSL_VERIFY_PEER, None);
    ctx.set_alpn_protocols(&[b"spdy/3.1"]);
    match ctx.set_CA_file(&Path::new("test/cert.pem")) {
        Ok(_) => {}
        Err(err) => panic!("Unexpected error {:?}", err)
    }
    // Now connect to the socket and make sure the protocol negotiation works...
    let stream = TcpStream::connect(localhost).unwrap();
    let stream = match SslStream::new(&ctx, stream) {
        Ok(stream) => stream,
        Err(err) => panic!("Expected success, got {:?}", err)
    };
    // SPDY is selected since that's the only thing the client supports.
    assert_eq!(b"spdy/3.1", stream.get_selected_alpn_protocol().unwrap());
}

#[cfg(feature="dtlsv1")]
#[cfg(test)]
mod dtlsv1 {
Loading