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use libc::size_t;
use std::io::Cursor;
use std::slice;
use std::sync::Arc;
#[cfg(feature = "aws-lc-rs")]
use rustls::crypto::aws_lc_rs;
#[cfg(feature = "ring")]
use rustls::crypto::ring;
use rustls::crypto::CryptoProvider;
use rustls::sign::SigningKey;
use rustls::SupportedCipherSuite;
use crate::cipher::rustls_supported_ciphersuite;
use crate::error::map_error;
use crate::{
arc_castable, box_castable, ffi_panic_boundary, free_arc, free_box, rustls_result,
set_arc_mut_ptr, set_boxed_mut_ptr, to_boxed_mut_ptr, try_clone_arc, try_mut_from_ptr,
try_mut_from_ptr_ptr, try_ref_from_ptr, try_ref_from_ptr_ptr, try_slice, try_slice_mut,
try_take,
};
box_castable! {
/// A `rustls_crypto_provider` builder.
pub struct rustls_crypto_provider_builder(Option<CryptoProviderBuilder>);
}
/// A builder for customizing a `CryptoProvider`. Can be used to install a process-wide default.
#[derive(Debug)]
pub struct CryptoProviderBuilder {
base: Arc<CryptoProvider>,
cipher_suites: Vec<SupportedCipherSuite>,
}
impl CryptoProviderBuilder {
fn build_provider(self) -> CryptoProvider {
let cipher_suites = match self.cipher_suites.is_empty() {
true => self.base.cipher_suites.clone(),
false => self.cipher_suites,
};
// Unfortunately we can't use the `..` syntax to fill in the rest of the provider
// fields, because we're working with `Arc<CryptoProvider>` as the base,
// not `CryptoProvider`.
// TODO(#450): once MSRV is 1.76+, use `Arc::unwrap_or_clone`.
CryptoProvider {
cipher_suites,
kx_groups: self.base.kx_groups.clone(),
signature_verification_algorithms: self.base.signature_verification_algorithms,
secure_random: self.base.secure_random,
key_provider: self.base.key_provider,
}
}
}
/// Constructs a new `rustls_crypto_provider_builder` using the process-wide default crypto
/// provider as the base crypto provider to be customized.
///
/// When this function returns `rustls_result::Ok` a pointer to the `rustls_crypto_provider_builder`
/// is written to `builder_out`. It returns `rustls_result::NoDefaultCryptoProvider` if no default
/// provider has been registered.
///
/// The caller owns the returned `rustls_crypto_provider_builder` and must free it using
/// `rustls_crypto_provider_builder_free`.
///
/// This function is typically used for customizing the default crypto provider for specific
/// connections. For example, a typical workflow might be to:
///
/// * Either:
/// * Use the default `aws-lc-rs` or `*ring*` provider that rustls-ffi is built with based on
/// the `CRYPTO_PROVIDER` build variable.
/// * Call `rustls_crypto_provider_builder_new_with_base` with the desired provider, and
/// then install it as the process default with
/// `rustls_crypto_provider_builder_build_as_default`.
/// * Afterward, as required for customization:
/// * Use `rustls_crypto_provider_builder_new_from_default` to get a builder backed by the
/// default crypto provider.
/// * Use `rustls_crypto_provider_builder_set_cipher_suites` to customize the supported
/// ciphersuites.
/// * Use `rustls_crypto_provider_builder_build` to build a customized provider.
/// * Provide that customized provider to client or server configuration builders.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_builder_new_from_default(
builder_out: *mut *mut rustls_crypto_provider_builder,
) -> rustls_result {
ffi_panic_boundary! {
let provider_out = try_mut_from_ptr_ptr!(builder_out);
let base = match get_default_or_install_from_crate_features() {
Some(provider) => provider,
None => return rustls_result::NoDefaultCryptoProvider,
};
set_boxed_mut_ptr(
provider_out,
Some(CryptoProviderBuilder {
base,
cipher_suites: Vec::default(),
}),
);
rustls_result::Ok
}
}
/// Constructs a new `rustls_crypto_provider_builder` using the given `rustls_crypto_provider`
/// as the base crypto provider to be customized.
///
/// The caller owns the returned `rustls_crypto_provider_builder` and must free it using
/// `rustls_crypto_provider_builder_free`.
///
/// This function can be used for setting the default process wide crypto provider,
/// or for constructing a custom crypto provider for a specific connection. A typical
/// workflow could be to:
///
/// * Call `rustls_crypto_provider_builder_new_with_base` with a custom provider
/// * Install the custom provider as the process-wide default with
/// `rustls_crypto_provider_builder_build_as_default`.
///
/// Or, for per-connection customization:
///
/// * Call `rustls_crypto_provider_builder_new_with_base` with a custom provider
/// * Use `rustls_crypto_provider_builder_set_cipher_suites` to customize the supported
/// ciphersuites.
/// * Use `rustls_crypto_provider_builder_build` to build a customized provider.
/// * Provide that customized provider to client or server configuration builders.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_builder_new_with_base(
base: *const rustls_crypto_provider,
) -> *mut rustls_crypto_provider_builder {
ffi_panic_boundary! {
to_boxed_mut_ptr(Some(CryptoProviderBuilder {
base: try_clone_arc!(base),
cipher_suites: Vec::default(),
}))
}
}
/// Customize the supported ciphersuites of the `rustls_crypto_provider_builder`.
///
/// Returns an error if the builder has already been built. Overwrites any previously
/// set ciphersuites.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_builder_set_cipher_suites(
builder: *mut rustls_crypto_provider_builder,
cipher_suites: *const *const rustls_supported_ciphersuite,
cipher_suites_len: size_t,
) -> rustls_result {
ffi_panic_boundary! {
let builder = try_mut_from_ptr!(builder);
let builder = match builder {
Some(builder) => builder,
None => return rustls_result::AlreadyUsed,
};
let cipher_suites = try_slice!(cipher_suites, cipher_suites_len);
let mut supported_cipher_suites = Vec::new();
for cs in cipher_suites {
let cs = *cs;
let cs = try_ref_from_ptr!(cs);
supported_cipher_suites.push(*cs);
}
builder.cipher_suites = supported_cipher_suites;
rustls_result::Ok
}
}
/// Builds a `rustls_crypto_provider` from the builder and returns it. Returns an error if the
/// builder has already been built.
///
/// The `rustls_crypto_provider_builder` builder is consumed and should not be used
/// for further calls, except to `rustls_crypto_provider_builder_free`. The caller must
/// still free the builder after a successful build.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_builder_build(
builder: *mut rustls_crypto_provider_builder,
provider_out: *mut *const rustls_crypto_provider,
) -> rustls_result {
ffi_panic_boundary! {
let builder = try_mut_from_ptr!(builder);
set_arc_mut_ptr(
try_ref_from_ptr_ptr!(provider_out),
try_take!(builder).build_provider(),
);
rustls_result::Ok
}
}
/// Builds a `rustls_crypto_provider` from the builder and sets it as the
/// process-wide default crypto provider.
///
/// Afterward, the default provider can be retrieved using `rustls_crypto_provider_default`.
///
/// This can only be done once per process, and will return an error if a
/// default provider has already been set, or if the builder has already been built.
///
/// The `rustls_crypto_provider_builder` builder is consumed and should not be used
/// for further calls, except to `rustls_crypto_provider_builder_free`. The caller must
/// still free the builder after a successful build.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_builder_build_as_default(
builder: *mut rustls_crypto_provider_builder,
) -> rustls_result {
let builder = try_mut_from_ptr!(builder);
match try_take!(builder).build_provider().install_default() {
Ok(_) => rustls_result::Ok,
Err(_) => rustls_result::AlreadyUsed,
}
}
/// Free the `rustls_crypto_provider_builder`.
///
/// Calling with `NULL` is fine.
/// Must not be called twice with the same value.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_builder_free(
builder: *mut rustls_crypto_provider_builder,
) {
ffi_panic_boundary! {
free_box(builder);
}
}
/// Return the `rustls_crypto_provider` backed by the `*ring*` cryptography library.
///
/// The caller owns the returned `rustls_crypto_provider` and must free it using
/// `rustls_crypto_provider_free`.
#[no_mangle]
#[cfg(feature = "ring")]
pub extern "C" fn rustls_ring_crypto_provider() -> *const rustls_crypto_provider {
ffi_panic_boundary! {
Arc::into_raw(Arc::new(ring::default_provider())) as *const rustls_crypto_provider
}
}
/// Return the `rustls_crypto_provider` backed by the `aws-lc-rs` cryptography library.
///
/// The caller owns the returned `rustls_crypto_provider` and must free it using
/// `rustls_crypto_provider_free`.
#[no_mangle]
#[cfg(feature = "aws-lc-rs")]
pub extern "C" fn rustls_aws_lc_rs_crypto_provider() -> *const rustls_crypto_provider {
ffi_panic_boundary! {
Arc::into_raw(Arc::new(aws_lc_rs::default_provider())) as *const rustls_crypto_provider
}
}
/// Retrieve a pointer to the process default `rustls_crypto_provider`.
///
/// This may return `NULL` if no process default provider has been set using
/// `rustls_crypto_provider_builder_build_default`.
///
/// Caller owns the returned `rustls_crypto_provider` and must free it w/ `rustls_crypto_provider_free`.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_default() -> *const rustls_crypto_provider {
ffi_panic_boundary! {
match CryptoProvider::get_default() {
Some(provider) => Arc::into_raw(provider.clone()) as *const rustls_crypto_provider,
None => core::ptr::null(),
}
}
}
arc_castable! {
/// A C representation of a Rustls [`CryptoProvider`].
pub struct rustls_crypto_provider(CryptoProvider);
}
/// Returns the number of ciphersuites the `rustls_crypto_provider` supports.
///
/// You can use this to know the maximum allowed index for use with
/// `rustls_crypto_provider_ciphersuites_get`.
///
/// This function will return 0 if the `provider` is NULL.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_ciphersuites_len(
provider: *const rustls_crypto_provider,
) -> usize {
ffi_panic_boundary! {
try_clone_arc!(provider).cipher_suites.len()
}
}
/// Retrieve a pointer to a supported ciphersuite of the `rustls_crypto_provider`.
///
/// This function will return NULL if the `provider` is NULL, or if the index is out of bounds
/// with respect to `rustls_crypto_provider_ciphersuites_len`.
///
/// The lifetime of the returned `rustls_supported_ciphersuite` is equal to the lifetime of the
/// `provider` and should not be used after the `provider` is freed.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_ciphersuites_get(
provider: *const rustls_crypto_provider,
index: usize,
) -> *const rustls_supported_ciphersuite {
ffi_panic_boundary! {
match try_clone_arc!(provider).cipher_suites.get(index) {
Some(ciphersuite) => ciphersuite as *const SupportedCipherSuite as *const _,
None => core::ptr::null(),
}
}
}
/// Load a private key from the provided PEM content using the crypto provider.
///
/// `private_key` must point to a buffer of `private_key_len` bytes, containing
/// a PEM-encoded private key. The exact formats supported will differ based on
/// the crypto provider in use. The default providers support PKCS#1, PKCS#8 or
/// SEC1 formats.
///
/// When this function returns `rustls_result::Ok` a pointer to a `rustls_signing_key`
/// is written to `signing_key_out`. The caller owns the returned `rustls_signing_key`
/// and must free it with `rustls_signing_key_free`.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_load_key(
provider: *const rustls_crypto_provider,
private_key: *const u8,
private_key_len: size_t,
signing_key_out: *mut *mut rustls_signing_key,
) -> rustls_result {
ffi_panic_boundary! {
let provider = try_clone_arc!(provider);
let private_key_pem = try_slice!(private_key, private_key_len);
let signing_key_out = try_mut_from_ptr_ptr!(signing_key_out);
let private_key_der = match rustls_pemfile::private_key(&mut Cursor::new(private_key_pem)) {
Ok(Some(p)) => p,
_ => return rustls_result::PrivateKeyParseError,
};
let private_key = match provider.key_provider.load_private_key(private_key_der) {
Ok(key) => key,
Err(e) => return map_error(e),
};
set_boxed_mut_ptr(signing_key_out, private_key);
rustls_result::Ok
}
}
/// Write `len` bytes of cryptographically secure random data to `buff` using the crypto provider.
///
/// `buff` must point to a buffer of at least `len` bytes. The caller maintains ownership
/// of the buffer.
///
/// Returns `RUSTLS_RESULT_OK` on success, or `RUSTLS_RESULT_GET_RANDOM_FAILED` on failure.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_random(
provider: *const rustls_crypto_provider,
buff: *mut u8,
len: size_t,
) -> rustls_result {
ffi_panic_boundary! {
match try_clone_arc!(provider)
.secure_random
.fill(try_slice_mut!(buff, len))
{
Ok(_) => rustls_result::Ok,
Err(_) => rustls_result::GetRandomFailed,
}
}
}
/// Frees the `rustls_crypto_provider`.
///
/// Calling with `NULL` is fine.
/// Must not be called twice with the same value.
#[no_mangle]
pub extern "C" fn rustls_crypto_provider_free(provider: *const rustls_crypto_provider) {
ffi_panic_boundary! {
free_arc(provider);
}
}
/// Returns the number of ciphersuites the default process-wide crypto provider supports.
///
/// You can use this to know the maximum allowed index for use with
/// `rustls_default_crypto_provider_ciphersuites_get`.
///
/// This function will return 0 if no process-wide default `rustls_crypto_provider` is available.
#[no_mangle]
pub extern "C" fn rustls_default_crypto_provider_ciphersuites_len() -> usize {
ffi_panic_boundary! {
match get_default_or_install_from_crate_features() {
Some(provider) => provider.cipher_suites.len(),
None => return 0,
}
}
}
/// Retrieve a pointer to a supported ciphersuite of the default process-wide crypto provider.
///
/// This function will return NULL if the `provider` is NULL, or if the index is out of bounds
/// with respect to `rustls_default_crypto_provider_ciphersuites_len`.
///
/// The lifetime of the returned `rustls_supported_ciphersuite` is static, as the process-wide
/// default provider lives for as long as the process.
#[no_mangle]
pub extern "C" fn rustls_default_crypto_provider_ciphersuites_get(
index: usize,
) -> *const rustls_supported_ciphersuite {
ffi_panic_boundary! {
let default_provider = match get_default_or_install_from_crate_features() {
Some(provider) => provider,
None => return core::ptr::null(),
};
match default_provider.cipher_suites.get(index) {
Some(ciphersuite) => ciphersuite as *const SupportedCipherSuite as *const _,
None => core::ptr::null(),
}
}
}
/// Write `len` bytes of cryptographically secure random data to `buff` using the process-wide
/// default crypto provider.
///
/// `buff` must point to a buffer of at least `len` bytes. The caller maintains ownership
/// of the buffer.
///
/// Returns `RUSTLS_RESULT_OK` on success, and one of `RUSTLS_RESULT_NO_DEFAULT_CRYPTO_PROVIDER`
/// or `RUSTLS_RESULT_GET_RANDOM_FAILED` on failure.
#[no_mangle]
pub extern "C" fn rustls_default_crypto_provider_random(
buff: *mut u8,
len: size_t,
) -> rustls_result {
ffi_panic_boundary! {
match get_default_or_install_from_crate_features() {
Some(provider) => match provider.secure_random.fill(try_slice_mut!(buff, len)) {
Ok(_) => rustls_result::Ok,
Err(_) => rustls_result::GetRandomFailed,
},
None => rustls_result::NoDefaultCryptoProvider,
}
}
}
box_castable! {
/// A signing key that can be used to construct a certified key.
// NOTE: we box cast an arc over the dyn trait per the pattern described
// in our docs[0] for dynamically sized types.
// [0]: <https://github.com/rustls/rustls-ffi/blob/main/CONTRIBUTING.md#dynamically-sized-types>
pub struct rustls_signing_key(Arc<dyn SigningKey>);
}
impl rustls_signing_key {
/// Frees the `rustls_signing_key`. This is safe to call with a `NULL` argument, but
/// must not be called twice with the same value.
#[no_mangle]
pub extern "C" fn rustls_signing_key_free(signing_key: *mut rustls_signing_key) {
ffi_panic_boundary! {
free_box(signing_key);
}
}
}
pub(crate) fn get_default_or_install_from_crate_features() -> Option<Arc<CryptoProvider>> {
// If a process-wide default has already been installed, return it.
if let Some(provider) = CryptoProvider::get_default() {
return Some(provider.clone());
}
let provider = match provider_from_crate_features() {
Some(provider) => provider,
None => return None,
};
// Ignore the error resulting from us losing a race to install the default,
// and accept the outcome.
let _ = provider.install_default();
// Safety: we can unwrap safely here knowing we've just set the default, or
// lost a race to something else setting the default.
Some(CryptoProvider::get_default().unwrap().clone())
}
fn provider_from_crate_features() -> Option<CryptoProvider> {
// Provider default is unambiguously aws-lc-rs
#[cfg(all(feature = "aws-lc-rs", not(feature = "ring")))]
{
return Some(aws_lc_rs::default_provider());
}
// Provider default is unambiguously ring
#[cfg(all(feature = "ring", not(feature = "aws-lc-rs")))]
{
return Some(ring::default_provider());
}
// Both features activated - no clear default provider based on
// crate features.
#[allow(unreachable_code)]
None
}
#[cfg(all(test, not(miri)))]
mod tests {
use std::ptr;
use super::*;
use rustls_result;
/// Simple smoketest of CSRNG fill with specific provider.
#[test]
fn random_data() {
let provider = rustls_crypto_provider_default();
assert!(!provider.is_null());
// NULL buffer should return an error.
let result = rustls_crypto_provider_random(provider, ptr::null_mut(), 1337);
assert_eq!(result, rustls_result::NullParameter);
let mut buff = vec![0; 32];
// NULL provider should return an error and not touch buff.
let result = rustls_crypto_provider_random(ptr::null(), buff.as_mut_ptr(), buff.len());
assert_eq!(buff, vec![0; 32]);
assert_eq!(result, rustls_result::NullParameter);
// Proper parameters should return OK and overwrite the buffer.
let result = rustls_crypto_provider_random(provider, buff.as_mut_ptr(), buff.len());
assert_eq!(result, rustls_result::Ok);
assert_ne!(buff, vec![0; 32]);
}
/// Simple smoketest of CSRNG fill with default provider.
#[test]
fn default_random_data() {
// NULL buffer should return an error.
let result = rustls_default_crypto_provider_random(ptr::null_mut(), 1337);
assert_eq!(result, rustls_result::NullParameter);
let mut buff = vec![0; 32];
// Proper parameters should return OK and overwrite the buffer.
let result = rustls_default_crypto_provider_random(buff.as_mut_ptr(), buff.len());
assert_eq!(result, rustls_result::Ok);
assert_ne!(buff, vec![0; 32]);
}
}