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    928

    //! Rivest–Shamir–Adleman cryptosystem
    //!
    //! RSA is one of the earliest asymmetric public key encryption schemes.
    //! Like many other cryptosystems, RSA relies on the presumed difficulty of a hard
    //! mathematical problem, namely factorization of the product of two large prime
    //! numbers. At the moment there does not exist an algorithm that can factor such
    //! large numbers in reasonable time. RSA is used in a wide variety of
    //! applications including digital signatures and key exchanges such as
    //! establishing a TLS/SSL connection.
    //!
    //! The RSA acronym is derived from the first letters of the surnames of the
    //! algorithm's founding trio.
    //!
    //! # Example
    //!
    //! Generate a 2048-bit RSA key pair and use the public key to encrypt some data.
    //!
    //! ```rust
    //!
    //! extern crate openssl;
    //!
    //! use openssl::rsa::{Rsa, Padding};
    //!
    //! fn main() {
    //!     let rsa = Rsa::generate(2048).unwrap();
    //!     let data = b"foobar";
    //!     let mut buf = vec![0; rsa.size() as usize];
    //!     let encrypted_len = rsa.public_encrypt(data, &mut buf, Padding::PKCS1).unwrap();
    //! }
    //! ```
    use ffi;
    use foreign_types::{ForeignType, ForeignTypeRef};
    use libc::c_int;
    use std::fmt;
    use std::mem;
    use std::ptr;

    use bn::{BigNum, BigNumRef};
    use error::ErrorStack;
    use pkey::{HasPrivate, HasPublic, Private, Public};
    use util::ForeignTypeRefExt;
    use {cvt, cvt_n, cvt_p};

    /// Type of encryption padding to use.
    ///
    /// Random length padding is primarily used to prevent attackers from
    /// predicting or knowing the exact length of a plaintext message that
    /// can possibly lead to breaking encryption.
    #[derive(Debug, Copy, Clone, PartialEq, Eq)]
    pub struct Padding(c_int);

    impl Padding {
        pub const NONE: Padding = Padding(ffi::RSA_NO_PADDING);
        pub const PKCS1: Padding = Padding(ffi::RSA_PKCS1_PADDING);
        pub const PKCS1_OAEP: Padding = Padding(ffi::RSA_PKCS1_OAEP_PADDING);
        pub const PKCS1_PSS: Padding = Padding(ffi::RSA_PKCS1_PSS_PADDING);

        /// Creates a `Padding` from an integer representation.
        pub fn from_raw(value: c_int) -> Padding {
            Padding(value)
        }

        /// Returns the integer representation of `Padding`.
        #[allow(clippy::trivially_copy_pass_by_ref)]
        pub fn as_raw(&self) -> c_int {
            self.0
        }
    }

    generic_foreign_type_and_impl_send_sync! {
        type CType = ffi::RSA;
        fn drop = ffi::RSA_free;

        /// An RSA key.
        pub struct Rsa<T>;

        /// Reference to `RSA`
        pub struct RsaRef<T>;
    }

    impl<T> Clone for Rsa<T> {
        fn clone(&self) -> Rsa<T> {
            (**self).to_owned()
        }
    }

    impl<T> ToOwned for RsaRef<T> {
        type Owned = Rsa<T>;

        fn to_owned(&self) -> Rsa<T> {
            unsafe {
                ffi::RSA_up_ref(self.as_ptr());
                Rsa::from_ptr(self.as_ptr())
            }
        }
    }

    impl<T> RsaRef<T>
    where
        T: HasPrivate,
    {
        private_key_to_pem! {
            /// Serializes the private key to a PEM-encoded PKCS#1 RSAPrivateKey structure.
            ///
            /// The output will have a header of `-----BEGIN RSA PRIVATE KEY-----`.
            ///
            /// This corresponds to [`PEM_write_bio_RSAPrivateKey`].
            ///
            /// [`PEM_write_bio_RSAPrivateKey`]: https://www.openssl.org/docs/man1.1.0/crypto/PEM_write_bio_RSAPrivateKey.html
            private_key_to_pem,
            /// Serializes the private key to a PEM-encoded encrypted PKCS#1 RSAPrivateKey structure.
            ///
            /// The output will have a header of `-----BEGIN RSA PRIVATE KEY-----`.
            ///
            /// This corresponds to [`PEM_write_bio_RSAPrivateKey`].
            ///
            /// [`PEM_write_bio_RSAPrivateKey`]: https://www.openssl.org/docs/man1.1.0/crypto/PEM_write_bio_RSAPrivateKey.html
            private_key_to_pem_passphrase,
            ffi::PEM_write_bio_RSAPrivateKey
        }

        to_der! {
            /// Serializes the private key to a DER-encoded PKCS#1 RSAPrivateKey structure.
            ///
            /// This corresponds to [`i2d_RSAPrivateKey`].
            ///
            /// [`i2d_RSAPrivateKey`]: https://www.openssl.org/docs/man1.0.2/crypto/i2d_RSAPrivateKey.html
            private_key_to_der,
            ffi::i2d_RSAPrivateKey
        }

        /// Decrypts data using the private key, returning the number of decrypted bytes.
        ///
        /// # Panics
        ///
        /// Panics if `self` has no private components, or if `to` is smaller
        /// than `self.size()`.
        pub fn private_decrypt(
            &self,
            from: &[u8],
            to: &mut [u8],
            padding: Padding,
        ) -> Result<usize, ErrorStack> {
            assert!(from.len() <= i32::max_value() as usize);
            assert!(to.len() >= self.size() as usize);

            unsafe {
                let len = cvt_n(ffi::RSA_private_decrypt(
                    from.len() as c_int,
                    from.as_ptr(),
                    to.as_mut_ptr(),
                    self.as_ptr(),
                    padding.0,
                ))?;
                Ok(len as usize)
            }
        }

        /// Encrypts data using the private key, returning the number of encrypted bytes.
        ///
        /// # Panics
        ///
        /// Panics if `self` has no private components, or if `to` is smaller
        /// than `self.size()`.
        pub fn private_encrypt(
            &self,
            from: &[u8],
            to: &mut [u8],
            padding: Padding,
        ) -> Result<usize, ErrorStack> {
            assert!(from.len() <= i32::max_value() as usize);
            assert!(to.len() >= self.size() as usize);

            unsafe {
                let len = cvt_n(ffi::RSA_private_encrypt(
                    from.len() as c_int,
                    from.as_ptr(),
                    to.as_mut_ptr(),
                    self.as_ptr(),
                    padding.0,
                ))?;
                Ok(len as usize)
            }
        }

        /// Returns a reference to the private exponent of the key.
        ///
        /// This corresponds to [`RSA_get0_key`].
        ///
        /// [`RSA_get0_key`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn d(&self) -> &BigNumRef {
            unsafe {
                let mut d = ptr::null();
                RSA_get0_key(self.as_ptr(), ptr::null_mut(), ptr::null_mut(), &mut d);
                BigNumRef::from_const_ptr(d)
            }
        }

        /// Returns a reference to the first factor of the exponent of the key.
        ///
        /// This corresponds to [`RSA_get0_factors`].
        ///
        /// [`RSA_get0_factors`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn p(&self) -> Option<&BigNumRef> {
            unsafe {
                let mut p = ptr::null();
                RSA_get0_factors(self.as_ptr(), &mut p, ptr::null_mut());
                BigNumRef::from_const_ptr_opt(p)
            }
        }

        /// Returns a reference to the second factor of the exponent of the key.
        ///
        /// This corresponds to [`RSA_get0_factors`].
        ///
        /// [`RSA_get0_factors`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn q(&self) -> Option<&BigNumRef> {
            unsafe {
                let mut q = ptr::null();
                RSA_get0_factors(self.as_ptr(), ptr::null_mut(), &mut q);
                BigNumRef::from_const_ptr_opt(q)
            }
        }

        /// Returns a reference to the first exponent used for CRT calculations.
        ///
        /// This corresponds to [`RSA_get0_crt_params`].
        ///
        /// [`RSA_get0_crt_params`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn dmp1(&self) -> Option<&BigNumRef> {
            unsafe {
                let mut dp = ptr::null();
                RSA_get0_crt_params(self.as_ptr(), &mut dp, ptr::null_mut(), ptr::null_mut());
                BigNumRef::from_const_ptr_opt(dp)
            }
        }

        /// Returns a reference to the second exponent used for CRT calculations.
        ///
        /// This corresponds to [`RSA_get0_crt_params`].
        ///
        /// [`RSA_get0_crt_params`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn dmq1(&self) -> Option<&BigNumRef> {
            unsafe {
                let mut dq = ptr::null();
                RSA_get0_crt_params(self.as_ptr(), ptr::null_mut(), &mut dq, ptr::null_mut());
                BigNumRef::from_const_ptr_opt(dq)
            }
        }

        /// Returns a reference to the coefficient used for CRT calculations.
        ///
        /// This corresponds to [`RSA_get0_crt_params`].
        ///
        /// [`RSA_get0_crt_params`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn iqmp(&self) -> Option<&BigNumRef> {
            unsafe {
                let mut qi = ptr::null();
                RSA_get0_crt_params(self.as_ptr(), ptr::null_mut(), ptr::null_mut(), &mut qi);
                BigNumRef::from_const_ptr_opt(qi)
            }
        }

        /// Validates RSA parameters for correctness
        ///
        /// This corresponds to [`RSA_check_key`].
        ///
        /// [`RSA_check_key`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_check_key.html
        pub fn check_key(&self) -> Result<bool, ErrorStack> {
            unsafe {
                let result = ffi::RSA_check_key(self.as_ptr()) as i32;
                if result == -1 {
                    Err(ErrorStack::get())
                } else {
                    Ok(result == 1)
                }
            }
        }
    }

    impl<T> RsaRef<T>
    where
        T: HasPublic,
    {
        to_pem! {
            /// Serializes the public key into a PEM-encoded SubjectPublicKeyInfo structure.
            ///
            /// The output will have a header of `-----BEGIN PUBLIC KEY-----`.
            ///
            /// This corresponds to [`PEM_write_bio_RSA_PUBKEY`].
            ///
            /// [`PEM_write_bio_RSA_PUBKEY`]: https://www.openssl.org/docs/man1.0.2/crypto/pem.html
            public_key_to_pem,
            ffi::PEM_write_bio_RSA_PUBKEY
        }

        to_der! {
            /// Serializes the public key into a DER-encoded SubjectPublicKeyInfo structure.
            ///
            /// This corresponds to [`i2d_RSA_PUBKEY`].
            ///
            /// [`i2d_RSA_PUBKEY`]: https://www.openssl.org/docs/man1.1.0/crypto/i2d_RSA_PUBKEY.html
            public_key_to_der,
            ffi::i2d_RSA_PUBKEY
        }

        to_pem! {
            /// Serializes the public key into a PEM-encoded PKCS#1 RSAPublicKey structure.
            ///
            /// The output will have a header of `-----BEGIN RSA PUBLIC KEY-----`.
            ///
            /// This corresponds to [`PEM_write_bio_RSAPublicKey`].
            ///
            /// [`PEM_write_bio_RSAPublicKey`]: https://www.openssl.org/docs/man1.0.2/crypto/pem.html
            public_key_to_pem_pkcs1,
            ffi::PEM_write_bio_RSAPublicKey
        }

        to_der! {
            /// Serializes the public key into a DER-encoded PKCS#1 RSAPublicKey structure.
            ///
            /// This corresponds to [`i2d_RSAPublicKey`].
            ///
            /// [`i2d_RSAPublicKey`]: https://www.openssl.org/docs/man1.0.2/crypto/i2d_RSAPublicKey.html
            public_key_to_der_pkcs1,
            ffi::i2d_RSAPublicKey
        }

        /// Returns the size of the modulus in bytes.
        ///
        /// This corresponds to [`RSA_size`].
        ///
        /// [`RSA_size`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_size.html
        pub fn size(&self) -> u32 {
            unsafe { ffi::RSA_size(self.as_ptr()) as u32 }
        }

        /// Decrypts data using the public key, returning the number of decrypted bytes.
        ///
        /// # Panics
        ///
        /// Panics if `to` is smaller than `self.size()`.
        pub fn public_decrypt(
            &self,
            from: &[u8],
            to: &mut [u8],
            padding: Padding,
        ) -> Result<usize, ErrorStack> {
            assert!(from.len() <= i32::max_value() as usize);
            assert!(to.len() >= self.size() as usize);

            unsafe {
                let len = cvt_n(ffi::RSA_public_decrypt(
                    from.len() as c_int,
                    from.as_ptr(),
                    to.as_mut_ptr(),
                    self.as_ptr(),
                    padding.0,
                ))?;
                Ok(len as usize)
            }
        }

        /// Encrypts data using the public key, returning the number of encrypted bytes.
        ///
        /// # Panics
        ///
        /// Panics if `to` is smaller than `self.size()`.
        pub fn public_encrypt(
            &self,
            from: &[u8],
            to: &mut [u8],
            padding: Padding,
        ) -> Result<usize, ErrorStack> {
            assert!(from.len() <= i32::max_value() as usize);
            assert!(to.len() >= self.size() as usize);

            unsafe {
                let len = cvt_n(ffi::RSA_public_encrypt(
                    from.len() as c_int,
                    from.as_ptr(),
                    to.as_mut_ptr(),
                    self.as_ptr(),
                    padding.0,
                ))?;
                Ok(len as usize)
            }
        }

        /// Returns a reference to the modulus of the key.
        ///
        /// This corresponds to [`RSA_get0_key`].
        ///
        /// [`RSA_get0_key`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn n(&self) -> &BigNumRef {
            unsafe {
                let mut n = ptr::null();
                RSA_get0_key(self.as_ptr(), &mut n, ptr::null_mut(), ptr::null_mut());
                BigNumRef::from_const_ptr(n)
            }
        }

        /// Returns a reference to the public exponent of the key.
        ///
        /// This corresponds to [`RSA_get0_key`].
        ///
        /// [`RSA_get0_key`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_get0_key.html
        pub fn e(&self) -> &BigNumRef {
            unsafe {
                let mut e = ptr::null();
                RSA_get0_key(self.as_ptr(), ptr::null_mut(), &mut e, ptr::null_mut());
                BigNumRef::from_const_ptr(e)
            }
        }
    }

    impl Rsa<Public> {
        /// Creates a new RSA key with only public components.
        ///
        /// `n` is the modulus common to both public and private key.
        /// `e` is the public exponent.
        ///
        /// This corresponds to [`RSA_new`] and uses [`RSA_set0_key`].
        ///
        /// [`RSA_new`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_new.html
        /// [`RSA_set0_key`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_set0_key.html
        pub fn from_public_components(n: BigNum, e: BigNum) -> Result<Rsa<Public>, ErrorStack> {
            unsafe {
                let rsa = cvt_p(ffi::RSA_new())?;
                RSA_set0_key(rsa, n.as_ptr(), e.as_ptr(), ptr::null_mut());
                mem::forget((n, e));
                Ok(Rsa::from_ptr(rsa))
            }
        }

        from_pem! {
            /// Decodes a PEM-encoded SubjectPublicKeyInfo structure containing an RSA key.
            ///
            /// The input should have a header of `-----BEGIN PUBLIC KEY-----`.
            ///
            /// This corresponds to [`PEM_read_bio_RSA_PUBKEY`].
            ///
            /// [`PEM_read_bio_RSA_PUBKEY`]: https://www.openssl.org/docs/man1.0.2/crypto/PEM_read_bio_RSA_PUBKEY.html
            public_key_from_pem,
            Rsa<Public>,
            ffi::PEM_read_bio_RSA_PUBKEY
        }

        from_pem! {
            /// Decodes a PEM-encoded PKCS#1 RSAPublicKey structure.
            ///
            /// The input should have a header of `-----BEGIN RSA PUBLIC KEY-----`.
            ///
            /// This corresponds to [`PEM_read_bio_RSAPublicKey`].
            ///
            /// [`PEM_read_bio_RSAPublicKey`]: https://www.openssl.org/docs/man1.0.2/crypto/PEM_read_bio_RSAPublicKey.html
            public_key_from_pem_pkcs1,
            Rsa<Public>,
            ffi::PEM_read_bio_RSAPublicKey
        }

        from_der! {
            /// Decodes a DER-encoded SubjectPublicKeyInfo structure containing an RSA key.
            ///
            /// This corresponds to [`d2i_RSA_PUBKEY`].
            ///
            /// [`d2i_RSA_PUBKEY`]: https://www.openssl.org/docs/man1.0.2/crypto/d2i_RSA_PUBKEY.html
            public_key_from_der,
            Rsa<Public>,
            ffi::d2i_RSA_PUBKEY
        }

        from_der! {
            /// Decodes a DER-encoded PKCS#1 RSAPublicKey structure.
            ///
            /// This corresponds to [`d2i_RSAPublicKey`].
            ///
            /// [`d2i_RSAPublicKey`]: https://www.openssl.org/docs/man1.0.2/crypto/d2i_RSA_PUBKEY.html
            public_key_from_der_pkcs1,
            Rsa<Public>,
            ffi::d2i_RSAPublicKey
        }
    }

    pub struct RsaPrivateKeyBuilder {
        rsa: Rsa<Private>,
    }

    impl RsaPrivateKeyBuilder {
        /// Creates a new `RsaPrivateKeyBuilder`.
        ///
        /// `n` is the modulus common to both public and private key.
        /// `e` is the public exponent and `d` is the private exponent.
        ///
        /// This corresponds to [`RSA_new`] and uses [`RSA_set0_key`].
        ///
        /// [`RSA_new`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_new.html
        /// [`RSA_set0_key`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_set0_key.html
        pub fn new(n: BigNum, e: BigNum, d: BigNum) -> Result<RsaPrivateKeyBuilder, ErrorStack> {
            unsafe {
                let rsa = cvt_p(ffi::RSA_new())?;
                RSA_set0_key(rsa, n.as_ptr(), e.as_ptr(), d.as_ptr());
                mem::forget((n, e, d));
                Ok(RsaPrivateKeyBuilder {
                    rsa: Rsa::from_ptr(rsa),
                })
            }
        }

        /// Sets the factors of the Rsa key.
        ///
        /// `p` and `q` are the first and second factors of `n`.
        ///
        /// This correspond to [`RSA_set0_factors`].
        ///
        /// [`RSA_set0_factors`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_set0_factors.html
        // FIXME should be infallible
        pub fn set_factors(self, p: BigNum, q: BigNum) -> Result<RsaPrivateKeyBuilder, ErrorStack> {
            unsafe {
                RSA_set0_factors(self.rsa.as_ptr(), p.as_ptr(), q.as_ptr());
                mem::forget((p, q));
            }
            Ok(self)
        }

        /// Sets the Chinese Remainder Theorem params of the Rsa key.
        ///
        /// `dmp1`, `dmq1`, and `iqmp` are the exponents and coefficient for
        /// CRT calculations which is used to speed up RSA operations.
        ///
        /// This correspond to [`RSA_set0_crt_params`].
        ///
        /// [`RSA_set0_crt_params`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_set0_crt_params.html
        // FIXME should be infallible
        pub fn set_crt_params(
            self,
            dmp1: BigNum,
            dmq1: BigNum,
            iqmp: BigNum,
        ) -> Result<RsaPrivateKeyBuilder, ErrorStack> {
            unsafe {
                RSA_set0_crt_params(
                    self.rsa.as_ptr(),
                    dmp1.as_ptr(),
                    dmq1.as_ptr(),
                    iqmp.as_ptr(),
                );
                mem::forget((dmp1, dmq1, iqmp));
            }
            Ok(self)
        }

        /// Returns the Rsa key.
        pub fn build(self) -> Rsa<Private> {
            self.rsa
        }
    }

    impl Rsa<Private> {
        /// Creates a new RSA key with private components (public components are assumed).
        ///
        /// This a convenience method over
        /// `Rsa::build(n, e, d)?.set_factors(p, q)?.set_crt_params(dmp1, dmq1, iqmp)?.build()`
        #[allow(clippy::too_many_arguments, clippy::many_single_char_names)]
        pub fn from_private_components(
            n: BigNum,
            e: BigNum,
            d: BigNum,
            p: BigNum,
            q: BigNum,
            dmp1: BigNum,
            dmq1: BigNum,
            iqmp: BigNum,
        ) -> Result<Rsa<Private>, ErrorStack> {
            Ok(RsaPrivateKeyBuilder::new(n, e, d)?
                .set_factors(p, q)?
                .set_crt_params(dmp1, dmq1, iqmp)?
                .build())
        }

        /// Generates a public/private key pair with the specified size.
        ///
        /// The public exponent will be 65537.
        ///
        /// This corresponds to [`RSA_generate_key_ex`].
        ///
        /// [`RSA_generate_key_ex`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_generate_key_ex.html
        pub fn generate(bits: u32) -> Result<Rsa<Private>, ErrorStack> {
            let e = BigNum::from_u32(ffi::RSA_F4 as u32)?;
            Rsa::generate_with_e(bits, &e)
        }

        /// Generates a public/private key pair with the specified size and a custom exponent.
        ///
        /// Unless you have specific needs and know what you're doing, use `Rsa::generate` instead.
        ///
        /// This corresponds to [`RSA_generate_key_ex`].
        ///
        /// [`RSA_generate_key_ex`]: https://www.openssl.org/docs/man1.1.0/crypto/RSA_generate_key_ex.html
        pub fn generate_with_e(bits: u32, e: &BigNumRef) -> Result<Rsa<Private>, ErrorStack> {
            unsafe {
                let rsa = Rsa::from_ptr(cvt_p(ffi::RSA_new())?);
                cvt(ffi::RSA_generate_key_ex(
                    rsa.0,
                    bits as c_int,
                    e.as_ptr(),
                    ptr::null_mut(),
                ))?;
                Ok(rsa)
            }
        }

        // FIXME these need to identify input formats
        private_key_from_pem! {
            /// Deserializes a private key from a PEM-encoded PKCS#1 RSAPrivateKey structure.
            ///
            /// This corresponds to [`PEM_read_bio_RSAPrivateKey`].
            ///
            /// [`PEM_read_bio_RSAPrivateKey`]: https://www.openssl.org/docs/man1.1.0/crypto/PEM_read_bio_RSAPrivateKey.html
            private_key_from_pem,

            /// Deserializes a private key from a PEM-encoded encrypted PKCS#1 RSAPrivateKey structure.
            ///
            /// This corresponds to [`PEM_read_bio_RSAPrivateKey`].
            ///
            /// [`PEM_read_bio_RSAPrivateKey`]: https://www.openssl.org/docs/man1.1.0/crypto/PEM_read_bio_RSAPrivateKey.html
            private_key_from_pem_passphrase,

            /// Deserializes a private key from a PEM-encoded encrypted PKCS#1 RSAPrivateKey structure.
            ///
            /// The callback should fill the password into the provided buffer and return its length.
            ///
            /// This corresponds to [`PEM_read_bio_RSAPrivateKey`].
            ///
            /// [`PEM_read_bio_RSAPrivateKey`]: https://www.openssl.org/docs/man1.1.0/crypto/PEM_read_bio_RSAPrivateKey.html
            private_key_from_pem_callback,
            Rsa<Private>,
            ffi::PEM_read_bio_RSAPrivateKey
        }

        from_der! {
            /// Decodes a DER-encoded PKCS#1 RSAPrivateKey structure.
            ///
            /// This corresponds to [`d2i_RSAPrivateKey`].
            ///
            /// [`d2i_RSAPrivateKey`]: https://www.openssl.org/docs/man1.0.2/crypto/d2i_RSA_PUBKEY.html
            private_key_from_der,
            Rsa<Private>,
            ffi::d2i_RSAPrivateKey
        }
    }

    impl<T> fmt::Debug for Rsa<T> {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            write!(f, "Rsa")
        }
    }

    cfg_if! {
        if #[cfg(any(ossl110, libressl273))] {
            use ffi::{
                RSA_get0_key, RSA_get0_factors, RSA_get0_crt_params, RSA_set0_key, RSA_set0_factors,
                RSA_set0_crt_params,
            };
        } else {
            #[allow(bad_style)]
            unsafe fn RSA_get0_key(
                r: *const ffi::RSA,
                n: *mut *const ffi::BIGNUM,
                e: *mut *const ffi::BIGNUM,
                d: *mut *const ffi::BIGNUM,
            ) {
                if !n.is_null() {
                    *n = (*r).n;
                }
                if !e.is_null() {
                    *e = (*r).e;
                }
                if !d.is_null() {
                    *d = (*r).d;
                }
            }

            #[allow(bad_style)]
            unsafe fn RSA_get0_factors(
                r: *const ffi::RSA,
                p: *mut *const ffi::BIGNUM,
                q: *mut *const ffi::BIGNUM,
            ) {
                if !p.is_null() {
                    *p = (*r).p;
                }
                if !q.is_null() {
                    *q = (*r).q;
                }
            }

            #[allow(bad_style)]
            unsafe fn RSA_get0_crt_params(
                r: *const ffi::RSA,
                dmp1: *mut *const ffi::BIGNUM,
                dmq1: *mut *const ffi::BIGNUM,
                iqmp: *mut *const ffi::BIGNUM,
            ) {
                if !dmp1.is_null() {
                    *dmp1 = (*r).dmp1;
                }
                if !dmq1.is_null() {
                    *dmq1 = (*r).dmq1;
                }
                if !iqmp.is_null() {
                    *iqmp = (*r).iqmp;
                }
            }

            #[allow(bad_style)]
            unsafe fn RSA_set0_key(
                r: *mut ffi::RSA,
                n: *mut ffi::BIGNUM,
                e: *mut ffi::BIGNUM,
                d: *mut ffi::BIGNUM,
            ) -> c_int {
                (*r).n = n;
                (*r).e = e;
                (*r).d = d;
                1
            }

            #[allow(bad_style)]
            unsafe fn RSA_set0_factors(
                r: *mut ffi::RSA,
                p: *mut ffi::BIGNUM,
                q: *mut ffi::BIGNUM,
            ) -> c_int {
                (*r).p = p;
                (*r).q = q;
                1
            }

            #[allow(bad_style)]
            unsafe fn RSA_set0_crt_params(
                r: *mut ffi::RSA,
                dmp1: *mut ffi::BIGNUM,
                dmq1: *mut ffi::BIGNUM,
                iqmp: *mut ffi::BIGNUM,
            ) -> c_int {
                (*r).dmp1 = dmp1;
                (*r).dmq1 = dmq1;
                (*r).iqmp = iqmp;
                1
            }
        }
    }

    #[cfg(test)]
    mod test {
        use symm::Cipher;

        use super::*;

        #[test]
        fn test_from_password() {
            let key = include_bytes!("../test/rsa-encrypted.pem");
            Rsa::private_key_from_pem_passphrase(key, b"mypass").unwrap();
        }

        #[test]
        fn test_from_password_callback() {
            let mut password_queried = false;
            let key = include_bytes!("../test/rsa-encrypted.pem");
            Rsa::private_key_from_pem_callback(key, |password| {
                password_queried = true;
                password[..6].copy_from_slice(b"mypass");
                Ok(6)
            })
            .unwrap();

            assert!(password_queried);
        }

        #[test]
        fn test_to_password() {
            let key = Rsa::generate(2048).unwrap();
            let pem = key
                .private_key_to_pem_passphrase(Cipher::aes_128_cbc(), b"foobar")
                .unwrap();
            Rsa::private_key_from_pem_passphrase(&pem, b"foobar").unwrap();
            assert!(Rsa::private_key_from_pem_passphrase(&pem, b"fizzbuzz").is_err());
        }

        #[test]
        fn test_public_encrypt_private_decrypt_with_padding() {
            let key = include_bytes!("../test/rsa.pem.pub");
            let public_key = Rsa::public_key_from_pem(key).unwrap();

            let mut result = vec![0; public_key.size() as usize];
            let original_data = b"This is test";
            let len = public_key
                .public_encrypt(original_data, &mut result, Padding::PKCS1)
                .unwrap();
            assert_eq!(len, 256);

            let pkey = include_bytes!("../test/rsa.pem");
            let private_key = Rsa::private_key_from_pem(pkey).unwrap();
            let mut dec_result = vec![0; private_key.size() as usize];
            let len = private_key
                .private_decrypt(&result, &mut dec_result, Padding::PKCS1)
                .unwrap();

            assert_eq!(&dec_result[..len], original_data);
        }

        #[test]
        fn test_private_encrypt() {
            let k0 = super::Rsa::generate(512).unwrap();
            let k0pkey = k0.public_key_to_pem().unwrap();
            let k1 = super::Rsa::public_key_from_pem(&k0pkey).unwrap();

            let msg = vec![0xdeu8, 0xadu8, 0xd0u8, 0x0du8];

            let mut emesg = vec![0; k0.size() as usize];
            k0.private_encrypt(&msg, &mut emesg, Padding::PKCS1)
                .unwrap();
            let mut dmesg = vec![0; k1.size() as usize];
            let len = k1
                .public_decrypt(&emesg, &mut dmesg, Padding::PKCS1)
                .unwrap();
            assert_eq!(msg, &dmesg[..len]);
        }

        #[test]
        fn test_public_encrypt() {
            let k0 = super::Rsa::generate(512).unwrap();
            let k0pkey = k0.private_key_to_pem().unwrap();
            let k1 = super::Rsa::private_key_from_pem(&k0pkey).unwrap();

            let msg = vec![0xdeu8, 0xadu8, 0xd0u8, 0x0du8];

            let mut emesg = vec![0; k0.size() as usize];
            k0.public_encrypt(&msg, &mut emesg, Padding::PKCS1).unwrap();
            let mut dmesg = vec![0; k1.size() as usize];
            let len = k1
                .private_decrypt(&emesg, &mut dmesg, Padding::PKCS1)
                .unwrap();
            assert_eq!(msg, &dmesg[..len]);
        }

        #[test]
        fn test_public_key_from_pem_pkcs1() {
            let key = include_bytes!("../test/pkcs1.pem.pub");
            Rsa::public_key_from_pem_pkcs1(key).unwrap();
        }

        #[test]
        #[should_panic]
        fn test_public_key_from_pem_pkcs1_file_panic() {
            let key = include_bytes!("../test/key.pem.pub");
            Rsa::public_key_from_pem_pkcs1(key).unwrap();
        }

        #[test]
        fn test_public_key_to_pem_pkcs1() {
            let keypair = super::Rsa::generate(512).unwrap();
            let pubkey_pem = keypair.public_key_to_pem_pkcs1().unwrap();
            super::Rsa::public_key_from_pem_pkcs1(&pubkey_pem).unwrap();
        }

        #[test]
        #[should_panic]
        fn test_public_key_from_pem_pkcs1_generate_panic() {
            let keypair = super::Rsa::generate(512).unwrap();
            let pubkey_pem = keypair.public_key_to_pem().unwrap();
            super::Rsa::public_key_from_pem_pkcs1(&pubkey_pem).unwrap();
        }

        #[test]
        fn test_pem_pkcs1_encrypt() {
            let keypair = super::Rsa::generate(2048).unwrap();
            let pubkey_pem = keypair.public_key_to_pem_pkcs1().unwrap();
            let pubkey = super::Rsa::public_key_from_pem_pkcs1(&pubkey_pem).unwrap();
            let msg = b"Hello, world!";

            let mut encrypted = vec![0; pubkey.size() as usize];
            let len = pubkey
                .public_encrypt(msg, &mut encrypted, Padding::PKCS1)
                .unwrap();
            assert!(len > msg.len());
            let mut decrypted = vec![0; keypair.size() as usize];
            let len = keypair
                .private_decrypt(&encrypted, &mut decrypted, Padding::PKCS1)
                .unwrap();
            assert_eq!(len, msg.len());
            assert_eq!(&decrypted[..len], msg);
        }

        #[test]
        fn test_pem_pkcs1_padding() {
            let keypair = super::Rsa::generate(2048).unwrap();
            let pubkey_pem = keypair.public_key_to_pem_pkcs1().unwrap();
            let pubkey = super::Rsa::public_key_from_pem_pkcs1(&pubkey_pem).unwrap();
            let msg = b"foo";

            let mut encrypted1 = vec![0; pubkey.size() as usize];
            let mut encrypted2 = vec![0; pubkey.size() as usize];
            let len1 = pubkey
                .public_encrypt(msg, &mut encrypted1, Padding::PKCS1)
                .unwrap();
            let len2 = pubkey
                .public_encrypt(msg, &mut encrypted2, Padding::PKCS1)
                .unwrap();
            assert!(len1 > (msg.len() + 1));
            assert_eq!(len1, len2);
            assert_ne!(encrypted1, encrypted2);
        }

        #[test]
        #[allow(clippy::redundant_clone)]
        fn clone() {
            let key = Rsa::generate(2048).unwrap();
            drop(key.clone());
        }

        #[test]
        fn generate_with_e() {
            let e = BigNum::from_u32(0x10001).unwrap();
            Rsa::generate_with_e(2048, &e).unwrap();
        }
    }