Struct openssl::nid::Nid

source ·

pub struct Nid(_);

Expand description

A numerical identifier for an OpenSSL object.

Objects in OpenSSL can have a short name, a long name, and a numerical identifier (NID). For convenience, objects are usually represented in source code using these numeric identifiers.

Users should generally not need to create new Nids.

Examples

To view the integer representation of a Nid:

use openssl::nid::Nid;

assert!(Nid::AES_256_GCM.as_raw() == 901);

External Documentation

The following documentation provides context about Nids and their usage in OpenSSL.

Obj_nid2obj

Implementations§

source §

impl Nid

source

pub fn from_raw(raw: c_int) -> Nid

Create a Nid from an integer representation.

Examples found in repository ?

src/hash.rs (line 190)

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    pub fn type_(&self) -> Nid {
        Nid::from_raw(unsafe { ffi::EVP_MD_type(self.0) })
    }

More examples

Hide additional examples

src/asn1.rs (line 625)

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    pub fn nid(&self) -> Nid {
        unsafe { Nid::from_raw(ffi::OBJ_obj2nid(self.as_ptr())) }
    }

src/md.rs (line 233)

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    pub fn type_(&self) -> Nid {
        unsafe { Nid::from_raw(ffi::EVP_MD_type(self.as_ptr())) }
    }

src/symm.rs (line 97)

    pub fn nid(&self) -> Nid {
        let nid = unsafe { ffi::EVP_CIPHER_nid(self.0) };
        Nid::from_raw(nid)
    }

src/cipher.rs (line 456)

    pub fn nid(&self) -> Nid {
        let nid = unsafe { ffi::EVP_CIPHER_nid(self.as_ptr()) };
        Nid::from_raw(nid)
    }

src/ssl/mod.rs (line 2023)

    pub fn cipher_nid(&self) -> Option<Nid> {
        let n = unsafe { ffi::SSL_CIPHER_get_cipher_nid(self.as_ptr()) };
        if n == 0 {
            None
        } else {
            Some(Nid::from_raw(n))
        }
    }

Additional examples can be found in:

src/ec.rs

source

pub fn as_raw(&self) -> c_int

Return the integer representation of a Nid.

Examples found in repository ?

src/ec.rs (line 136)

    pub fn from_curve_name(nid: Nid) -> Result<EcGroup, ErrorStack> {
        unsafe {
            init();
            cvt_p(ffi::EC_GROUP_new_by_curve_name(nid.as_raw())).map(EcGroup)
        }
    }

    /// Returns the group for given parameters
    #[corresponds(EC_GROUP_new_curve_GFp)]
    pub fn from_components(
        p: BigNum,
        a: BigNum,
        b: BigNum,
        ctx: &mut BigNumContextRef,
    ) -> Result<EcGroup, ErrorStack> {
        unsafe {
            cvt_p(ffi::EC_GROUP_new_curve_GFp(
                p.as_ptr(),
                a.as_ptr(),
                b.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(EcGroup)
        }
    }
}

impl EcGroupRef {
    /// Places the components of a curve over a prime field in the provided `BigNum`s.
    /// The components make up the formula `y^2 mod p = x^3 + ax + b mod p`.
    #[corresponds(EC_GROUP_get_curve_GFp)]
    pub fn components_gfp(
        &self,
        p: &mut BigNumRef,
        a: &mut BigNumRef,
        b: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_GROUP_get_curve_GFp(
                self.as_ptr(),
                p.as_ptr(),
                a.as_ptr(),
                b.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Places the components of a curve over a binary field in the provided `BigNum`s.
    /// The components make up the formula `y^2 + xy = x^3 + ax^2 + b`.
    ///
    /// In this form `p` relates to the irreducible polynomial.  Each bit represents
    /// a term in the polynomial.  It will be set to 3 `1`s or 5 `1`s depending on
    /// using a trinomial or pentanomial.
    #[corresponds(EC_GROUP_get_curve_GF2m)]
    #[cfg(not(any(boringssl, osslconf = "OPENSSL_NO_EC2M")))]
    pub fn components_gf2m(
        &self,
        p: &mut BigNumRef,
        a: &mut BigNumRef,
        b: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_GROUP_get_curve_GF2m(
                self.as_ptr(),
                p.as_ptr(),
                a.as_ptr(),
                b.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Places the cofactor of the group in the provided `BigNum`.
    #[corresponds(EC_GROUP_get_cofactor)]
    pub fn cofactor(
        &self,
        cofactor: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_GROUP_get_cofactor(
                self.as_ptr(),
                cofactor.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Returns the degree of the curve.
    #[corresponds(EC_GROUP_get_degree)]
    pub fn degree(&self) -> u32 {
        unsafe { ffi::EC_GROUP_get_degree(self.as_ptr()) as u32 }
    }

    /// Returns the number of bits in the group order.
    #[corresponds(EC_GROUP_order_bits)]
    #[cfg(ossl110)]
    pub fn order_bits(&self) -> u32 {
        unsafe { ffi::EC_GROUP_order_bits(self.as_ptr()) as u32 }
    }

    /// Returns the generator for the given curve as an [`EcPoint`].
    #[corresponds(EC_GROUP_get0_generator)]
    pub fn generator(&self) -> &EcPointRef {
        unsafe {
            let ptr = ffi::EC_GROUP_get0_generator(self.as_ptr());
            EcPointRef::from_const_ptr(ptr)
        }
    }

    /// Sets the generator point for the given curve
    #[corresponds(EC_GROUP_set_generator)]
    pub fn set_generator(
        &mut self,
        generator: EcPoint,
        order: BigNum,
        cofactor: BigNum,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_GROUP_set_generator(
                self.as_ptr(),
                generator.as_ptr(),
                order.as_ptr(),
                cofactor.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Places the order of the curve in the provided `BigNum`.
    #[corresponds(EC_GROUP_get_order)]
    pub fn order(
        &self,
        order: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_GROUP_get_order(
                self.as_ptr(),
                order.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Sets the flag determining if the group corresponds to a named curve or must be explicitly
    /// parameterized.
    ///
    /// This defaults to `EXPLICIT_CURVE` in OpenSSL 1.0.1 and 1.0.2, but `NAMED_CURVE` in OpenSSL
    /// 1.1.0.
    #[corresponds(EC_GROUP_set_asn1_flag)]
    pub fn set_asn1_flag(&mut self, flag: Asn1Flag) {
        unsafe {
            ffi::EC_GROUP_set_asn1_flag(self.as_ptr(), flag.0);
        }
    }

    /// Returns the name of the curve, if a name is associated.
    #[corresponds(EC_GROUP_get_curve_name)]
    pub fn curve_name(&self) -> Option<Nid> {
        let nid = unsafe { ffi::EC_GROUP_get_curve_name(self.as_ptr()) };
        if nid > 0 {
            Some(Nid::from_raw(nid))
        } else {
            None
        }
    }
}

foreign_type_and_impl_send_sync! {
    type CType = ffi::EC_POINT;
    fn drop = ffi::EC_POINT_free;

    /// Represents a point on the curve
    pub struct EcPoint;
    /// A reference a borrowed [`EcPoint`].
    pub struct EcPointRef;
}

impl EcPointRef {
    /// Computes `a + b`, storing the result in `self`.
    #[corresponds(EC_POINT_add)]
    pub fn add(
        &mut self,
        group: &EcGroupRef,
        a: &EcPointRef,
        b: &EcPointRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_add(
                group.as_ptr(),
                self.as_ptr(),
                a.as_ptr(),
                b.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Computes `q * m`, storing the result in `self`.
    #[corresponds(EC_POINT_mul)]
    pub fn mul(
        &mut self,
        group: &EcGroupRef,
        q: &EcPointRef,
        m: &BigNumRef,
        // FIXME should be &mut
        ctx: &BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_mul(
                group.as_ptr(),
                self.as_ptr(),
                ptr::null(),
                q.as_ptr(),
                m.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Computes `generator * n`, storing the result in `self`.
    #[corresponds(EC_POINT_mul)]
    pub fn mul_generator(
        &mut self,
        group: &EcGroupRef,
        n: &BigNumRef,
        // FIXME should be &mut
        ctx: &BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_mul(
                group.as_ptr(),
                self.as_ptr(),
                n.as_ptr(),
                ptr::null(),
                ptr::null(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Computes `generator * n + q * m`, storing the result in `self`.
    #[corresponds(EC_POINT_mul)]
    pub fn mul_full(
        &mut self,
        group: &EcGroupRef,
        n: &BigNumRef,
        q: &EcPointRef,
        m: &BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_mul(
                group.as_ptr(),
                self.as_ptr(),
                n.as_ptr(),
                q.as_ptr(),
                m.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Inverts `self`.
    #[corresponds(EC_POINT_invert)]
    // FIXME should be mutable
    pub fn invert(&mut self, group: &EcGroupRef, ctx: &BigNumContextRef) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_invert(
                group.as_ptr(),
                self.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Serializes the point to a binary representation.
    #[corresponds(EC_POINT_point2oct)]
    pub fn to_bytes(
        &self,
        group: &EcGroupRef,
        form: PointConversionForm,
        ctx: &mut BigNumContextRef,
    ) -> Result<Vec<u8>, ErrorStack> {
        unsafe {
            let len = ffi::EC_POINT_point2oct(
                group.as_ptr(),
                self.as_ptr(),
                form.0,
                ptr::null_mut(),
                0,
                ctx.as_ptr(),
            );
            if len == 0 {
                return Err(ErrorStack::get());
            }
            let mut buf = vec![0; len];
            let len = ffi::EC_POINT_point2oct(
                group.as_ptr(),
                self.as_ptr(),
                form.0,
                buf.as_mut_ptr(),
                len,
                ctx.as_ptr(),
            );
            if len == 0 {
                Err(ErrorStack::get())
            } else {
                Ok(buf)
            }
        }
    }

    /// Creates a new point on the specified curve with the same value.
    #[corresponds(EC_POINT_dup)]
    pub fn to_owned(&self, group: &EcGroupRef) -> Result<EcPoint, ErrorStack> {
        unsafe { cvt_p(ffi::EC_POINT_dup(self.as_ptr(), group.as_ptr())).map(EcPoint) }
    }

    /// Determines if this point is equal to another.
    #[corresponds(EC_POINT_cmp)]
    pub fn eq(
        &self,
        group: &EcGroupRef,
        other: &EcPointRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<bool, ErrorStack> {
        unsafe {
            let res = cvt_n(ffi::EC_POINT_cmp(
                group.as_ptr(),
                self.as_ptr(),
                other.as_ptr(),
                ctx.as_ptr(),
            ))?;
            Ok(res == 0)
        }
    }

    /// Places affine coordinates of a curve over a prime field in the provided
    /// `x` and `y` `BigNum`s.
    #[corresponds(EC_POINT_get_affine_coordinates)]
    #[cfg(ossl111)]
    pub fn affine_coordinates(
        &self,
        group: &EcGroupRef,
        x: &mut BigNumRef,
        y: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_get_affine_coordinates(
                group.as_ptr(),
                self.as_ptr(),
                x.as_ptr(),
                y.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Places affine coordinates of a curve over a prime field in the provided
    /// `x` and `y` `BigNum`s
    #[corresponds(EC_POINT_get_affine_coordinates_GFp)]
    pub fn affine_coordinates_gfp(
        &self,
        group: &EcGroupRef,
        x: &mut BigNumRef,
        y: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_get_affine_coordinates_GFp(
                group.as_ptr(),
                self.as_ptr(),
                x.as_ptr(),
                y.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Sets affine coordinates of a curve over a prime field using the provided
    /// `x` and `y` `BigNum`s
    #[corresponds(EC_POINT_set_affine_coordinates_GFp)]
    pub fn set_affine_coordinates_gfp(
        &mut self,
        group: &EcGroupRef,
        x: &BigNumRef,
        y: &BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_set_affine_coordinates_GFp(
                group.as_ptr(),
                self.as_ptr(),
                x.as_ptr(),
                y.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Places affine coordinates of a curve over a binary field in the provided
    /// `x` and `y` `BigNum`s
    #[corresponds(EC_POINT_get_affine_coordinates_GF2m)]
    #[cfg(not(any(boringssl, osslconf = "OPENSSL_NO_EC2M")))]
    pub fn affine_coordinates_gf2m(
        &self,
        group: &EcGroupRef,
        x: &mut BigNumRef,
        y: &mut BigNumRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<(), ErrorStack> {
        unsafe {
            cvt(ffi::EC_POINT_get_affine_coordinates_GF2m(
                group.as_ptr(),
                self.as_ptr(),
                x.as_ptr(),
                y.as_ptr(),
                ctx.as_ptr(),
            ))
            .map(|_| ())
        }
    }

    /// Checks if point is infinity
    #[corresponds(EC_POINT_is_at_infinity)]
    pub fn is_infinity(&self, group: &EcGroupRef) -> bool {
        unsafe {
            let res = ffi::EC_POINT_is_at_infinity(group.as_ptr(), self.as_ptr());
            res == 1
        }
    }

    /// Checks if point is on a given curve
    #[corresponds(EC_POINT_is_on_curve)]
    pub fn is_on_curve(
        &self,
        group: &EcGroupRef,
        ctx: &mut BigNumContextRef,
    ) -> Result<bool, ErrorStack> {
        unsafe {
            let res = cvt_n(ffi::EC_POINT_is_on_curve(
                group.as_ptr(),
                self.as_ptr(),
                ctx.as_ptr(),
            ))?;
            Ok(res == 1)
        }
    }
}

impl EcPoint {
    /// Creates a new point on the specified curve.
    #[corresponds(EC_POINT_new)]
    pub fn new(group: &EcGroupRef) -> Result<EcPoint, ErrorStack> {
        unsafe { cvt_p(ffi::EC_POINT_new(group.as_ptr())).map(EcPoint) }
    }

    /// Creates point from a binary representation
    #[corresponds(EC_POINT_oct2point)]
    pub fn from_bytes(
        group: &EcGroupRef,
        buf: &[u8],
        ctx: &mut BigNumContextRef,
    ) -> Result<EcPoint, ErrorStack> {
        let point = EcPoint::new(group)?;
        unsafe {
            cvt(ffi::EC_POINT_oct2point(
                group.as_ptr(),
                point.as_ptr(),
                buf.as_ptr(),
                buf.len(),
                ctx.as_ptr(),
            ))?;
        }
        Ok(point)
    }
}

generic_foreign_type_and_impl_send_sync! {
    type CType = ffi::EC_KEY;
    fn drop = ffi::EC_KEY_free;

    /// Public and optional private key on the given curve.
    pub struct EcKey<T>;
    /// A reference to an [`EcKey`].
    pub struct EcKeyRef<T>;
}

impl<T> EcKeyRef<T>
where
    T: HasPrivate,
{
    private_key_to_pem! {
        /// Serializes the private key to a PEM-encoded ECPrivateKey structure.
        ///
        /// The output will have a header of `-----BEGIN EC PRIVATE KEY-----`.
        #[corresponds(PEM_write_bio_ECPrivateKey)]
        private_key_to_pem,
        /// Serializes the private key to a PEM-encoded encrypted ECPrivateKey structure.
        ///
        /// The output will have a header of `-----BEGIN EC PRIVATE KEY-----`.
        #[corresponds(PEM_write_bio_ECPrivateKey)]
        private_key_to_pem_passphrase,
        ffi::PEM_write_bio_ECPrivateKey
    }

    to_der! {
        /// Serializes the private key into a DER-encoded ECPrivateKey structure.
        #[corresponds(i2d_ECPrivateKey)]
        private_key_to_der,
        ffi::i2d_ECPrivateKey
    }

    /// Returns the private key value.
    #[corresponds(EC_KEY_get0_private_key)]
    pub fn private_key(&self) -> &BigNumRef {
        unsafe {
            let ptr = ffi::EC_KEY_get0_private_key(self.as_ptr());
            BigNumRef::from_const_ptr(ptr)
        }
    }
}

impl<T> EcKeyRef<T>
where
    T: HasPublic,
{
    /// Returns the public key.
    #[corresponds(EC_KEY_get0_public_key)]
    pub fn public_key(&self) -> &EcPointRef {
        unsafe {
            let ptr = ffi::EC_KEY_get0_public_key(self.as_ptr());
            EcPointRef::from_const_ptr(ptr)
        }
    }

    to_pem! {
        /// Serializes the public key into a PEM-encoded SubjectPublicKeyInfo structure.
        ///
        /// The output will have a header of `-----BEGIN PUBLIC KEY-----`.
        #[corresponds(PEM_write_bio_EC_PUBKEY)]
        public_key_to_pem,
        ffi::PEM_write_bio_EC_PUBKEY
    }

    to_der! {
        /// Serializes the public key into a DER-encoded SubjectPublicKeyInfo structure.
        #[corresponds(i2d_EC_PUBKEY)]
        public_key_to_der,
        ffi::i2d_EC_PUBKEY
    }
}

impl<T> EcKeyRef<T>
where
    T: HasParams,
{
    /// Returns the key's group.
    #[corresponds(EC_KEY_get0_group)]
    pub fn group(&self) -> &EcGroupRef {
        unsafe {
            let ptr = ffi::EC_KEY_get0_group(self.as_ptr());
            EcGroupRef::from_const_ptr(ptr)
        }
    }

    /// Checks the key for validity.
    #[corresponds(EC_KEY_check_key)]
    pub fn check_key(&self) -> Result<(), ErrorStack> {
        unsafe { cvt(ffi::EC_KEY_check_key(self.as_ptr())).map(|_| ()) }
    }
}

impl<T> ToOwned for EcKeyRef<T> {
    type Owned = EcKey<T>;

    fn to_owned(&self) -> EcKey<T> {
        unsafe {
            let r = ffi::EC_KEY_up_ref(self.as_ptr());
            assert!(r == 1);
            EcKey::from_ptr(self.as_ptr())
        }
    }
}

impl EcKey<Params> {
    /// Constructs an `EcKey` corresponding to a known curve.
    ///
    /// It will not have an associated public or private key. This kind of key is primarily useful
    /// to be provided to the `set_tmp_ecdh` methods on `Ssl` and `SslContextBuilder`.
    #[corresponds(EC_KEY_new_by_curve_name)]
    pub fn from_curve_name(nid: Nid) -> Result<EcKey<Params>, ErrorStack> {
        unsafe {
            init();
            cvt_p(ffi::EC_KEY_new_by_curve_name(nid.as_raw())).map(|p| EcKey::from_ptr(p))
        }
    }

More examples

Hide additional examples

src/symm.rs (line 82)

    pub fn from_nid(nid: Nid) -> Option<Cipher> {
        let ptr = unsafe { ffi::EVP_get_cipherbyname(ffi::OBJ_nid2sn(nid.as_raw())) };
        if ptr.is_null() {
            None
        } else {
            Some(Cipher(ptr))
        }
    }

src/hash.rs (line 74)

    pub fn from_nid(type_: Nid) -> Option<MessageDigest> {
        unsafe {
            let ptr = ffi::EVP_get_digestbynid(type_.as_raw());
            if ptr.is_null() {
                None
            } else {
                Some(MessageDigest(ptr))
            }
        }
    }

src/md.rs (line 84)

    pub fn from_nid(type_: Nid) -> Option<&'static MdRef> {
        unsafe {
            let ptr = ffi::EVP_get_digestbynid(type_.as_raw());
            if ptr.is_null() {
                None
            } else {
                Some(MdRef::from_ptr(ptr as *mut _))
            }
        }
    }

src/cipher.rs (line 107)

    pub fn from_nid(nid: Nid) -> Option<&'static CipherRef> {
        unsafe {
            let ptr = ffi::EVP_get_cipherbyname(ffi::OBJ_nid2sn(nid.as_raw()));
            if ptr.is_null() {
                None
            } else {
                Some(CipherRef::from_ptr(ptr as *mut _))
            }
        }
    }

src/x509/mod.rs (line 844)

    pub fn new_nid(
        conf: Option<&ConfRef>,
        context: Option<&X509v3Context<'_>>,
        name: Nid,
        value: &str,
    ) -> Result<X509Extension, ErrorStack> {
        let value = CString::new(value).unwrap();
        unsafe {
            ffi::init();
            let conf = conf.map_or(ptr::null_mut(), ConfRef::as_ptr);
            let context = context.map_or(ptr::null_mut(), X509v3Context::as_ptr);
            let name = name.as_raw();
            let value = value.as_ptr() as *mut _;

            cvt_p(ffi::X509V3_EXT_nconf_nid(conf, context, name, value)).map(X509Extension)
        }
    }

    /// Adds an alias for an extension
    ///
    /// # Safety
    ///
    /// This method modifies global state without locking and therefore is not thread safe
    #[corresponds(X509V3_EXT_add_alias)]
    pub unsafe fn add_alias(to: Nid, from: Nid) -> Result<(), ErrorStack> {
        ffi::init();
        cvt(ffi::X509V3_EXT_add_alias(to.as_raw(), from.as_raw())).map(|_| ())
    }
}

/// A builder used to construct an `X509Name`.
pub struct X509NameBuilder(X509Name);

impl X509NameBuilder {
    /// Creates a new builder.
    pub fn new() -> Result<X509NameBuilder, ErrorStack> {
        unsafe {
            ffi::init();
            cvt_p(ffi::X509_NAME_new()).map(|p| X509NameBuilder(X509Name(p)))
        }
    }

    /// Add a field entry by str.
    ///
    /// This corresponds to [`X509_NAME_add_entry_by_txt`].
    ///
    /// [`X509_NAME_add_entry_by_txt`]: https://www.openssl.org/docs/man1.1.0/crypto/X509_NAME_add_entry_by_txt.html
    pub fn append_entry_by_text(&mut self, field: &str, value: &str) -> Result<(), ErrorStack> {
        unsafe {
            let field = CString::new(field).unwrap();
            assert!(value.len() <= c_int::max_value() as usize);
            cvt(ffi::X509_NAME_add_entry_by_txt(
                self.0.as_ptr(),
                field.as_ptr() as *mut _,
                ffi::MBSTRING_UTF8,
                value.as_ptr(),
                value.len() as c_int,
                -1,
                0,
            ))
            .map(|_| ())
        }
    }

    /// Add a field entry by str with a specific type.
    ///
    /// This corresponds to [`X509_NAME_add_entry_by_txt`].
    ///
    /// [`X509_NAME_add_entry_by_txt`]: https://www.openssl.org/docs/man1.1.0/crypto/X509_NAME_add_entry_by_txt.html
    pub fn append_entry_by_text_with_type(
        &mut self,
        field: &str,
        value: &str,
        ty: Asn1Type,
    ) -> Result<(), ErrorStack> {
        unsafe {
            let field = CString::new(field).unwrap();
            assert!(value.len() <= c_int::max_value() as usize);
            cvt(ffi::X509_NAME_add_entry_by_txt(
                self.0.as_ptr(),
                field.as_ptr() as *mut _,
                ty.as_raw(),
                value.as_ptr(),
                value.len() as c_int,
                -1,
                0,
            ))
            .map(|_| ())
        }
    }

    /// Add a field entry by NID.
    ///
    /// This corresponds to [`X509_NAME_add_entry_by_NID`].
    ///
    /// [`X509_NAME_add_entry_by_NID`]: https://www.openssl.org/docs/man1.1.0/crypto/X509_NAME_add_entry_by_NID.html
    pub fn append_entry_by_nid(&mut self, field: Nid, value: &str) -> Result<(), ErrorStack> {
        unsafe {
            assert!(value.len() <= c_int::max_value() as usize);
            cvt(ffi::X509_NAME_add_entry_by_NID(
                self.0.as_ptr(),
                field.as_raw(),
                ffi::MBSTRING_UTF8,
                value.as_ptr() as *mut _,
                value.len() as c_int,
                -1,
                0,
            ))
            .map(|_| ())
        }
    }

    /// Add a field entry by NID with a specific type.
    ///
    /// This corresponds to [`X509_NAME_add_entry_by_NID`].
    ///
    /// [`X509_NAME_add_entry_by_NID`]: https://www.openssl.org/docs/man1.1.0/crypto/X509_NAME_add_entry_by_NID.html
    pub fn append_entry_by_nid_with_type(
        &mut self,
        field: Nid,
        value: &str,
        ty: Asn1Type,
    ) -> Result<(), ErrorStack> {
        unsafe {
            assert!(value.len() <= c_int::max_value() as usize);
            cvt(ffi::X509_NAME_add_entry_by_NID(
                self.0.as_ptr(),
                field.as_raw(),
                ty.as_raw(),
                value.as_ptr() as *mut _,
                value.len() as c_int,
                -1,
                0,
            ))
            .map(|_| ())
        }
    }

    /// Return an `X509Name`.
    pub fn build(self) -> X509Name {
        self.0
    }
}

foreign_type_and_impl_send_sync! {
    type CType = ffi::X509_NAME;
    fn drop = ffi::X509_NAME_free;

    /// The names of an `X509` certificate.
    pub struct X509Name;
    /// Reference to `X509Name`.
    pub struct X509NameRef;
}

impl X509Name {
    /// Returns a new builder.
    pub fn builder() -> Result<X509NameBuilder, ErrorStack> {
        X509NameBuilder::new()
    }

    /// Loads subject names from a file containing PEM-formatted certificates.
    ///
    /// This is commonly used in conjunction with `SslContextBuilder::set_client_ca_list`.
    pub fn load_client_ca_file<P: AsRef<Path>>(file: P) -> Result<Stack<X509Name>, ErrorStack> {
        let file = CString::new(file.as_ref().as_os_str().to_str().unwrap()).unwrap();
        unsafe { cvt_p(ffi::SSL_load_client_CA_file(file.as_ptr())).map(|p| Stack::from_ptr(p)) }
    }

    from_der! {
        /// Deserializes a DER-encoded X509 name structure.
        ///
        /// This corresponds to [`d2i_X509_NAME`].
        ///
        /// [`d2i_X509_NAME`]: https://www.openssl.org/docs/manmaster/man3/d2i_X509_NAME.html
        from_der,
        X509Name,
        ffi::d2i_X509_NAME
    }
}

impl Stackable for X509Name {
    type StackType = ffi::stack_st_X509_NAME;
}

impl X509NameRef {
    /// Returns the name entries by the nid.
    pub fn entries_by_nid(&self, nid: Nid) -> X509NameEntries<'_> {
        X509NameEntries {
            name: self,
            nid: Some(nid),
            loc: -1,
        }
    }

    /// Returns an iterator over all `X509NameEntry` values
    pub fn entries(&self) -> X509NameEntries<'_> {
        X509NameEntries {
            name: self,
            nid: None,
            loc: -1,
        }
    }

    /// Compare two names, like [`Ord`] but it may fail.
    ///
    /// With OpenSSL versions from 3.0.0 this may return an error if the underlying `X509_NAME_cmp`
    /// call fails.
    /// For OpenSSL versions before 3.0.0 it will never return an error, but due to a bug it may
    /// spuriously return `Ordering::Less` if the `X509_NAME_cmp` call fails.
    #[corresponds(X509_NAME_cmp)]
    pub fn try_cmp(&self, other: &X509NameRef) -> Result<Ordering, ErrorStack> {
        let cmp = unsafe { ffi::X509_NAME_cmp(self.as_ptr(), other.as_ptr()) };
        if cfg!(ossl300) && cmp == -2 {
            return Err(ErrorStack::get());
        }
        Ok(cmp.cmp(&0))
    }

    to_der! {
        /// Serializes the certificate into a DER-encoded X509 name structure.
        ///
        /// This corresponds to [`i2d_X509_NAME`].
        ///
        /// [`i2d_X509_NAME`]: https://www.openssl.org/docs/man1.1.0/crypto/i2d_X509_NAME.html
        to_der,
        ffi::i2d_X509_NAME
    }
}

impl fmt::Debug for X509NameRef {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.debug_list().entries(self.entries()).finish()
    }
}

/// A type to destructure and examine an `X509Name`.
pub struct X509NameEntries<'a> {
    name: &'a X509NameRef,
    nid: Option<Nid>,
    loc: c_int,
}

impl<'a> Iterator for X509NameEntries<'a> {
    type Item = &'a X509NameEntryRef;

    fn next(&mut self) -> Option<&'a X509NameEntryRef> {
        unsafe {
            match self.nid {
                Some(nid) => {
                    // There is a `Nid` specified to search for
                    self.loc =
                        ffi::X509_NAME_get_index_by_NID(self.name.as_ptr(), nid.as_raw(), self.loc);
                    if self.loc == -1 {
                        return None;
                    }
                }
                None => {
                    // Iterate over all `Nid`s
                    self.loc += 1;
                    if self.loc >= ffi::X509_NAME_entry_count(self.name.as_ptr()) {
                        return None;
                    }
                }
            }

            let entry = ffi::X509_NAME_get_entry(self.name.as_ptr(), self.loc);

            Some(X509NameEntryRef::from_const_ptr_opt(entry).expect("entry must not be null"))
        }
    }