PkeyCtx secret derivation (2366b41c) · Commits · Public Repositories / Rust Openssl

openssl/src/pkey_ctx.rs

+120 −23

Original line number	Diff line number	Diff line
		@@ -21,7 +21,7 @@
		//! ```
		use crate::error::ErrorStack;
		use crate::md::MdRef;
		use crate::pkey::PKeyRef;
		use crate::pkey::{HasPublic, PKeyRef};
		use crate::rsa::Padding;
		#[cfg(any(ossl102, libressl310))]
		use crate::util;
		@@ -53,6 +53,48 @@ impl PkeyCtx {
		}

		impl PkeyCtxRef {
		/// Prepares the context for encryption using the public key.
		///
		/// This corresponds to [`EVP_PKEY_encrypt_init`].
		///
		/// [`EVP_PKEY_encrypt_init`]: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_encrypt_init.html
		#[inline]
		pub fn encrypt_init(&mut self) -> Result<(), ErrorStack> {
		unsafe {
		cvt(ffi::EVP_PKEY_encrypt_init(self.as_ptr()))?;
		}

		Ok(())
		}

		/// Prepares the context for encryption using the private key.
		///
		/// This corresponds to [`EVP_PKEY_decrypt_init`].
		///
		/// [`EVP_PKEY_decrypt_init`]: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_decrypt_init.html
		#[inline]
		pub fn decrypt_init(&mut self) -> Result<(), ErrorStack> {
		unsafe {
		cvt(ffi::EVP_PKEY_decrypt_init(self.as_ptr()))?;
		}

		Ok(())
		}

		/// Prepares the context for shared secret derivation.
		///
		/// This corresponds to [`EVP_PKEY_derive_init`].
		///
		/// [`EVP_PKEY_derive_init`]: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_derive_init.html
		#[inline]
		pub fn derive_init(&mut self) -> Result<(), ErrorStack> {
		unsafe {
		cvt(ffi::EVP_PKEY_derive_init(self.as_ptr()))?;
		}

		Ok(())
		}

		/// Returns the RSA padding mode in use.
		///
		/// This is only useful for RSA keys.
		@@ -153,29 +195,17 @@ impl PkeyCtxRef {
		Ok(())
		}

		/// Prepares the context for encryption using the public key.
		/// Sets the peer key used for secret derivation.
		///
		/// This corresponds to [`EVP_PKEY_encrypt_init`].
		/// This corresponds to [`EVP_PKEY_derive_set_peer`].
		///
		/// [`EVP_PKEY_encrypt_init`]: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_encrypt_init.html
		#[inline]
		pub fn encrypt_init(&mut self) -> Result<(), ErrorStack> {
		/// [`EVP_PKEY_derive_set_peer`]: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_derive_set_peer.html
		pub fn derive_set_peer<T>(&mut self, key: &PKeyRef<T>) -> Result<(), ErrorStack>
		where
		T: HasPublic,
		{
		unsafe {
		cvt(ffi::EVP_PKEY_encrypt_init(self.as_ptr()))?;
		}

		Ok(())
		}

		/// Prepares the context for encryption using the private key.
		///
		/// This corresponds to [`EVP_PKEY_decrypt_init`].
		///
		/// [`EVP_PKEY_decrypt_init`]: https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_decrypt_init.html
		#[inline]
		pub fn decrypt_init(&mut self) -> Result<(), ErrorStack> {
		unsafe {
		cvt(ffi::EVP_PKEY_decrypt_init(self.as_ptr()))?;
		cvt(ffi::EVP_PKEY_derive_set_peer(self.as_ptr(), key.as_ptr()))?;
		}

		Ok(())
		@@ -183,7 +213,7 @@ impl PkeyCtxRef {

		/// Encrypts data using the public key.
		///
		/// If `to` is set to `None`, the an upper bound on the number of bytes required for the output buffer will be
		/// If `to` is set to `None`, an upper bound on the number of bytes required for the output buffer will be
		/// returned.
		///
		/// This corresponds to [`EVP_PKEY_encrypt`].
		@@ -217,7 +247,7 @@ impl PkeyCtxRef {

		/// Decrypts data using the private key.
		///
		/// If `to` is set to `None`, the an upper bound on the number of bytes required for the output buffer will be
		/// If `to` is set to `None`, an upper bound on the number of bytes required for the output buffer will be
		/// returned.
		///
		/// This corresponds to [`EVP_PKEY_decrypt`].
		@@ -248,12 +278,45 @@ impl PkeyCtxRef {
		out.truncate(base + len);
		Ok(len)
		}

		/// Derives a shared secrete between two keys.
		///
		/// If `buf` is set to `None`, an upper bound on the number of bytes required for the buffer will be returned.
		///
		/// This corresponds to [`EVP_PKEY_derive`].
		///
		/// [`EVP_PKEY_derive`]: https://www.openssl.org/docs/manmaster/crypto/EVP_PKEY_derive_init.html
		pub fn derive(&mut self, buf: Option<&mut [u8]>) -> Result<usize, ErrorStack> {
		let mut len = buf.as_ref().map_or(0, \|b\| b.len());
		unsafe {
		cvt(ffi::EVP_PKEY_derive(
		self.as_ptr(),
		buf.map_or(ptr::null_mut(), \|b\| b.as_mut_ptr()),
		&mut len,
		))?;
		}

		Ok(len)
		}

		/// Like [`Self::derive`] but appends the secret to a [`Vec`].
		pub fn derive_to_vec(&mut self, buf: &mut Vec<u8>) -> Result<usize, ErrorStack> {
		let base = buf.len();
		let len = self.derive(None)?;
		buf.resize(base + len, 0);
		let len = self.derive(Some(&mut buf[base..]))?;
		buf.truncate(base + len);
		Ok(len)
		}
		}

		#[cfg(test)]
		mod test {
		use super::*;
		use crate::dh::Dh;
		use crate::ec::{EcGroup, EcKey};
		use crate::md::Md;
		use crate::nid::Nid;
		use crate::pkey::PKey;
		use crate::rsa::Rsa;

		@@ -325,4 +388,38 @@ mod test {

		assert_eq!(pt, out);
		}

		#[test]
		fn dh_derive_without_components() {
		let key1 = Dh::params_from_pem(include_bytes!("../test/dhparams.pem")).unwrap();
		let key1 = PKey::from_dh(key1).unwrap();
		let key2 = Dh::params_from_pem(include_bytes!("../test/dhparams.pem"))
		.unwrap()
		.generate_key()
		.unwrap();
		let key2 = PKey::from_dh(key2).unwrap();

		let mut ctx = PkeyCtx::new(&key1).unwrap();
		ctx.derive_init().unwrap();
		ctx.derive_set_peer(&key2).unwrap();

		let mut buf = vec![];
		ctx.derive_to_vec(&mut buf).unwrap_err();
		}

		#[test]
		fn derive() {
		let group = EcGroup::from_curve_name(Nid::X9_62_PRIME256V1).unwrap();
		let key1 = EcKey::generate(&group).unwrap();
		let key1 = PKey::from_ec_key(key1).unwrap();
		let key2 = EcKey::generate(&group).unwrap();
		let key2 = PKey::from_ec_key(key2).unwrap();

		let mut ctx = PkeyCtx::new(&key1).unwrap();
		ctx.derive_init().unwrap();
		ctx.derive_set_peer(&key2).unwrap();

		let mut buf = vec![];
		ctx.derive_to_vec(&mut buf).unwrap();
		}
		}