chore: add vendor dependencies for kauma build

vendor/openssl/src/asn1.rs

@@ -0,0 +1,910 @@
+#![deny(missing_docs)]
+
+//! Defines the format of certificates
+//!
+//! This module is used by [`x509`] and other certificate building functions
+//! to describe time, strings, and objects.
+//!
+//! Abstract Syntax Notation One is an interface description language.
+//! The specification comes from [X.208] by OSI, and rewritten in X.680.
+//! ASN.1 describes properties of an object with a type set.  Those types
+//! can be atomic, structured, choice, and other (CHOICE and ANY).  These
+//! types are expressed as a number and the assignment operator ::=  gives
+//! the type a name.
+//!
+//! The implementation here provides a subset of the ASN.1 types that OpenSSL
+//! uses, especially in the properties of a certificate used in HTTPS.
+//!
+//! [X.208]: https://www.itu.int/rec/T-REC-X.208-198811-W/en
+//! [`x509`]: ../x509/struct.X509Builder.html
+//!
+//! ## Examples
+//!
+//! ```
+//! use openssl::asn1::Asn1Time;
+//! let tomorrow = Asn1Time::days_from_now(1);
+//! ```
+use cfg_if::cfg_if;
+use foreign_types::{ForeignType, ForeignTypeRef};
+use libc::{c_char, c_int, c_long, time_t};
+use std::cmp::Ordering;
+use std::convert::TryInto;
+use std::ffi::CString;
+use std::fmt;
+use std::ptr;
+use std::str;
+
+use crate::bio::MemBio;
+use crate::bn::{BigNum, BigNumRef};
+use crate::error::ErrorStack;
+use crate::nid::Nid;
+use crate::stack::Stackable;
+use crate::string::OpensslString;
+use crate::{cvt, cvt_p, util};
+use openssl_macros::corresponds;
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_GENERALIZEDTIME;
+    fn drop = ffi::ASN1_GENERALIZEDTIME_free;
+
+    /// Non-UTC representation of time
+    ///
+    /// If a time can be represented by UTCTime, UTCTime is used
+    /// otherwise, ASN1_GENERALIZEDTIME is used.  This would be, for
+    /// example outside the year range of 1950-2049.
+    ///
+    /// [ASN1_GENERALIZEDTIME_set] documentation from OpenSSL provides
+    /// further details of implementation.  Note: these docs are from the master
+    /// branch as documentation on the 1.1.0 branch did not include this page.
+    ///
+    /// [ASN1_GENERALIZEDTIME_set]: https://www.openssl.org/docs/manmaster/man3/ASN1_GENERALIZEDTIME_set.html
+    pub struct Asn1GeneralizedTime;
+    /// Reference to a [`Asn1GeneralizedTime`]
+    ///
+    /// [`Asn1GeneralizedTime`]: struct.Asn1GeneralizedTime.html
+    pub struct Asn1GeneralizedTimeRef;
+}
+
+impl fmt::Display for Asn1GeneralizedTimeRef {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        unsafe {
+            let mem_bio = match MemBio::new() {
+                Err(_) => return f.write_str("error"),
+                Ok(m) => m,
+            };
+            let print_result = cvt(ffi::ASN1_GENERALIZEDTIME_print(
+                mem_bio.as_ptr(),
+                self.as_ptr(),
+            ));
+            match print_result {
+                Err(_) => f.write_str("error"),
+                Ok(_) => f.write_str(str::from_utf8_unchecked(mem_bio.get_buf())),
+            }
+        }
+    }
+}
+
+/// The type of an ASN.1 value.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub struct Asn1Type(c_int);
+
+#[allow(missing_docs)] // no need to document the constants
+impl Asn1Type {
+    pub const EOC: Asn1Type = Asn1Type(ffi::V_ASN1_EOC);
+
+    pub const BOOLEAN: Asn1Type = Asn1Type(ffi::V_ASN1_BOOLEAN);
+
+    pub const INTEGER: Asn1Type = Asn1Type(ffi::V_ASN1_INTEGER);
+
+    pub const BIT_STRING: Asn1Type = Asn1Type(ffi::V_ASN1_BIT_STRING);
+
+    pub const OCTET_STRING: Asn1Type = Asn1Type(ffi::V_ASN1_OCTET_STRING);
+
+    pub const NULL: Asn1Type = Asn1Type(ffi::V_ASN1_NULL);
+
+    pub const OBJECT: Asn1Type = Asn1Type(ffi::V_ASN1_OBJECT);
+
+    pub const OBJECT_DESCRIPTOR: Asn1Type = Asn1Type(ffi::V_ASN1_OBJECT_DESCRIPTOR);
+
+    pub const EXTERNAL: Asn1Type = Asn1Type(ffi::V_ASN1_EXTERNAL);
+
+    pub const REAL: Asn1Type = Asn1Type(ffi::V_ASN1_REAL);
+
+    pub const ENUMERATED: Asn1Type = Asn1Type(ffi::V_ASN1_ENUMERATED);
+
+    pub const UTF8STRING: Asn1Type = Asn1Type(ffi::V_ASN1_UTF8STRING);
+
+    pub const SEQUENCE: Asn1Type = Asn1Type(ffi::V_ASN1_SEQUENCE);
+
+    pub const SET: Asn1Type = Asn1Type(ffi::V_ASN1_SET);
+
+    pub const NUMERICSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_NUMERICSTRING);
+
+    pub const PRINTABLESTRING: Asn1Type = Asn1Type(ffi::V_ASN1_PRINTABLESTRING);
+
+    pub const T61STRING: Asn1Type = Asn1Type(ffi::V_ASN1_T61STRING);
+
+    pub const TELETEXSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_TELETEXSTRING);
+
+    pub const VIDEOTEXSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_VIDEOTEXSTRING);
+
+    pub const IA5STRING: Asn1Type = Asn1Type(ffi::V_ASN1_IA5STRING);
+
+    pub const UTCTIME: Asn1Type = Asn1Type(ffi::V_ASN1_UTCTIME);
+
+    pub const GENERALIZEDTIME: Asn1Type = Asn1Type(ffi::V_ASN1_GENERALIZEDTIME);
+
+    pub const GRAPHICSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_GRAPHICSTRING);
+
+    pub const ISO64STRING: Asn1Type = Asn1Type(ffi::V_ASN1_ISO64STRING);
+
+    pub const VISIBLESTRING: Asn1Type = Asn1Type(ffi::V_ASN1_VISIBLESTRING);
+
+    pub const GENERALSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_GENERALSTRING);
+
+    pub const UNIVERSALSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_UNIVERSALSTRING);
+
+    pub const BMPSTRING: Asn1Type = Asn1Type(ffi::V_ASN1_BMPSTRING);
+
+    /// Constructs an `Asn1Type` from a raw OpenSSL value.
+    pub fn from_raw(value: c_int) -> Self {
+        Asn1Type(value)
+    }
+
+    /// Returns the raw OpenSSL value represented by this type.
+    pub fn as_raw(&self) -> c_int {
+        self.0
+    }
+}
+
+/// Difference between two ASN1 times.
+///
+/// This `struct` is created by the [`diff`] method on [`Asn1TimeRef`]. See its
+/// documentation for more.
+///
+/// [`diff`]: struct.Asn1TimeRef.html#method.diff
+/// [`Asn1TimeRef`]: struct.Asn1TimeRef.html
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg(any(ossl102, boringssl))]
+pub struct TimeDiff {
+    /// Difference in days
+    pub days: c_int,
+    /// Difference in seconds.
+    ///
+    /// This is always less than the number of seconds in a day.
+    pub secs: c_int,
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_TIME;
+    fn drop = ffi::ASN1_TIME_free;
+    /// Time storage and comparison
+    ///
+    /// Asn1Time should be used to store and share time information
+    /// using certificates.  If Asn1Time is set using a string, it must
+    /// be in either YYMMDDHHMMSSZ, YYYYMMDDHHMMSSZ, or another ASN.1 format.
+    ///
+    /// [ASN_TIME_set] documentation at OpenSSL explains the ASN.1 implementation
+    /// used by OpenSSL.
+    ///
+    /// [ASN_TIME_set]: https://www.openssl.org/docs/manmaster/crypto/ASN1_TIME_set.html
+    pub struct Asn1Time;
+    /// Reference to an [`Asn1Time`]
+    ///
+    /// [`Asn1Time`]: struct.Asn1Time.html
+    pub struct Asn1TimeRef;
+}
+
+impl Asn1TimeRef {
+    /// Find difference between two times
+    #[corresponds(ASN1_TIME_diff)]
+    #[cfg(any(ossl102, boringssl))]
+    pub fn diff(&self, compare: &Self) -> Result<TimeDiff, ErrorStack> {
+        let mut days = 0;
+        let mut secs = 0;
+        let other = compare.as_ptr();
+
+        let err = unsafe { ffi::ASN1_TIME_diff(&mut days, &mut secs, self.as_ptr(), other) };
+
+        match err {
+            0 => Err(ErrorStack::get()),
+            _ => Ok(TimeDiff { days, secs }),
+        }
+    }
+
+    /// Compare two times
+    #[corresponds(ASN1_TIME_compare)]
+    #[cfg(any(ossl102, boringssl))]
+    pub fn compare(&self, other: &Self) -> Result<Ordering, ErrorStack> {
+        let d = self.diff(other)?;
+        if d.days > 0 || d.secs > 0 {
+            return Ok(Ordering::Less);
+        }
+        if d.days < 0 || d.secs < 0 {
+            return Ok(Ordering::Greater);
+        }
+
+        Ok(Ordering::Equal)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialEq for Asn1TimeRef {
+    fn eq(&self, other: &Asn1TimeRef) -> bool {
+        self.diff(other)
+            .map(|t| t.days == 0 && t.secs == 0)
+            .unwrap_or(false)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialEq<Asn1Time> for Asn1TimeRef {
+    fn eq(&self, other: &Asn1Time) -> bool {
+        self.diff(other)
+            .map(|t| t.days == 0 && t.secs == 0)
+            .unwrap_or(false)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialEq<Asn1Time> for &Asn1TimeRef {
+    fn eq(&self, other: &Asn1Time) -> bool {
+        self.diff(other)
+            .map(|t| t.days == 0 && t.secs == 0)
+            .unwrap_or(false)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialOrd for Asn1TimeRef {
+    fn partial_cmp(&self, other: &Asn1TimeRef) -> Option<Ordering> {
+        self.compare(other).ok()
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialOrd<Asn1Time> for Asn1TimeRef {
+    fn partial_cmp(&self, other: &Asn1Time) -> Option<Ordering> {
+        self.compare(other).ok()
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialOrd<Asn1Time> for &Asn1TimeRef {
+    fn partial_cmp(&self, other: &Asn1Time) -> Option<Ordering> {
+        self.compare(other).ok()
+    }
+}
+
+impl fmt::Display for Asn1TimeRef {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        unsafe {
+            let mem_bio = match MemBio::new() {
+                Err(_) => return f.write_str("error"),
+                Ok(m) => m,
+            };
+            let print_result = cvt(ffi::ASN1_TIME_print(mem_bio.as_ptr(), self.as_ptr()));
+            match print_result {
+                Err(_) => f.write_str("error"),
+                Ok(_) => f.write_str(str::from_utf8_unchecked(mem_bio.get_buf())),
+            }
+        }
+    }
+}
+
+impl fmt::Debug for Asn1TimeRef {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.to_string())
+    }
+}
+
+impl Asn1Time {
+    #[corresponds(ASN1_TIME_new)]
+    fn new() -> Result<Asn1Time, ErrorStack> {
+        ffi::init();
+
+        unsafe {
+            let handle = cvt_p(ffi::ASN1_TIME_new())?;
+            Ok(Asn1Time::from_ptr(handle))
+        }
+    }
+
+    #[corresponds(X509_gmtime_adj)]
+    fn from_period(period: c_long) -> Result<Asn1Time, ErrorStack> {
+        ffi::init();
+
+        unsafe {
+            let handle = cvt_p(ffi::X509_gmtime_adj(ptr::null_mut(), period))?;
+            Ok(Asn1Time::from_ptr(handle))
+        }
+    }
+
+    /// Creates a new time on specified interval in days from now
+    pub fn days_from_now(days: u32) -> Result<Asn1Time, ErrorStack> {
+        Asn1Time::from_period(days as c_long * 60 * 60 * 24)
+    }
+
+    /// Creates a new time from the specified `time_t` value
+    #[corresponds(ASN1_TIME_set)]
+    pub fn from_unix(time: time_t) -> Result<Asn1Time, ErrorStack> {
+        ffi::init();
+
+        unsafe {
+            let handle = cvt_p(ffi::ASN1_TIME_set(ptr::null_mut(), time))?;
+            Ok(Asn1Time::from_ptr(handle))
+        }
+    }
+
+    /// Creates a new time corresponding to the specified ASN1 time string.
+    #[corresponds(ASN1_TIME_set_string)]
+    #[allow(clippy::should_implement_trait)]
+    pub fn from_str(s: &str) -> Result<Asn1Time, ErrorStack> {
+        unsafe {
+            let s = CString::new(s).unwrap();
+
+            let time = Asn1Time::new()?;
+            cvt(ffi::ASN1_TIME_set_string(time.as_ptr(), s.as_ptr()))?;
+
+            Ok(time)
+        }
+    }
+
+    /// Creates a new time corresponding to the specified X509 time string.
+    ///
+    /// Requires BoringSSL or OpenSSL 1.1.1 or newer.
+    #[corresponds(ASN1_TIME_set_string_X509)]
+    #[cfg(any(ossl111, boringssl))]
+    pub fn from_str_x509(s: &str) -> Result<Asn1Time, ErrorStack> {
+        unsafe {
+            let s = CString::new(s).unwrap();
+
+            let time = Asn1Time::new()?;
+            cvt(ffi::ASN1_TIME_set_string_X509(time.as_ptr(), s.as_ptr()))?;
+
+            Ok(time)
+        }
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialEq for Asn1Time {
+    fn eq(&self, other: &Asn1Time) -> bool {
+        self.diff(other)
+            .map(|t| t.days == 0 && t.secs == 0)
+            .unwrap_or(false)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialEq<Asn1TimeRef> for Asn1Time {
+    fn eq(&self, other: &Asn1TimeRef) -> bool {
+        self.diff(other)
+            .map(|t| t.days == 0 && t.secs == 0)
+            .unwrap_or(false)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl<'a> PartialEq<&'a Asn1TimeRef> for Asn1Time {
+    fn eq(&self, other: &&'a Asn1TimeRef) -> bool {
+        self.diff(other)
+            .map(|t| t.days == 0 && t.secs == 0)
+            .unwrap_or(false)
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialOrd for Asn1Time {
+    fn partial_cmp(&self, other: &Asn1Time) -> Option<Ordering> {
+        self.compare(other).ok()
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl PartialOrd<Asn1TimeRef> for Asn1Time {
+    fn partial_cmp(&self, other: &Asn1TimeRef) -> Option<Ordering> {
+        self.compare(other).ok()
+    }
+}
+
+#[cfg(any(ossl102, boringssl))]
+impl<'a> PartialOrd<&'a Asn1TimeRef> for Asn1Time {
+    fn partial_cmp(&self, other: &&'a Asn1TimeRef) -> Option<Ordering> {
+        self.compare(other).ok()
+    }
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_STRING;
+    fn drop = ffi::ASN1_STRING_free;
+    /// Primary ASN.1 type used by OpenSSL
+    ///
+    /// Almost all ASN.1 types in OpenSSL are represented by ASN1_STRING
+    /// structures.  This implementation uses [ASN1_STRING-to_UTF8] to preserve
+    /// compatibility with Rust's String.
+    ///
+    /// [ASN1_STRING-to_UTF8]: https://www.openssl.org/docs/manmaster/crypto/ASN1_STRING_to_UTF8.html
+    pub struct Asn1String;
+    /// A reference to an [`Asn1String`].
+    pub struct Asn1StringRef;
+}
+
+impl Asn1StringRef {
+    /// Converts the ASN.1 underlying format to UTF8
+    ///
+    /// ASN.1 strings may utilize UTF-16, ASCII, BMP, or UTF8.  This is important to
+    /// consume the string in a meaningful way without knowing the underlying
+    /// format.
+    #[corresponds(ASN1_STRING_to_UTF8)]
+    pub fn as_utf8(&self) -> Result<OpensslString, ErrorStack> {
+        unsafe {
+            let mut ptr = ptr::null_mut();
+            let len = ffi::ASN1_STRING_to_UTF8(&mut ptr, self.as_ptr());
+            if len < 0 {
+                return Err(ErrorStack::get());
+            }
+
+            Ok(OpensslString::from_ptr(ptr as *mut c_char))
+        }
+    }
+
+    /// Return the string as an array of bytes.
+    ///
+    /// The bytes do not directly correspond to UTF-8 encoding.  To interact with
+    /// strings in rust, it is preferable to use [`as_utf8`]
+    ///
+    /// [`as_utf8`]: struct.Asn1String.html#method.as_utf8
+    #[corresponds(ASN1_STRING_get0_data)]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { util::from_raw_parts(ASN1_STRING_get0_data(self.as_ptr()), self.len()) }
+    }
+
+    /// Returns the number of bytes in the string.
+    #[corresponds(ASN1_STRING_length)]
+    pub fn len(&self) -> usize {
+        unsafe { ffi::ASN1_STRING_length(self.as_ptr()) as usize }
+    }
+
+    /// Determines if the string is empty.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
+
+impl fmt::Debug for Asn1StringRef {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.as_utf8() {
+            Ok(openssl_string) => openssl_string.fmt(fmt),
+            Err(_) => fmt.write_str("error"),
+        }
+    }
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_INTEGER;
+    fn drop = ffi::ASN1_INTEGER_free;
+
+    /// Numeric representation
+    ///
+    /// Integers in ASN.1 may include BigNum, int64 or uint64.  BigNum implementation
+    /// can be found within [`bn`] module.
+    ///
+    /// OpenSSL documentation includes [`ASN1_INTEGER_set`].
+    ///
+    /// [`bn`]: ../bn/index.html
+    /// [`ASN1_INTEGER_set`]: https://www.openssl.org/docs/manmaster/crypto/ASN1_INTEGER_set.html
+    pub struct Asn1Integer;
+    /// A reference to an [`Asn1Integer`].
+    pub struct Asn1IntegerRef;
+}
+
+impl Asn1Integer {
+    /// Converts a bignum to an `Asn1Integer`.
+    ///
+    /// Corresponds to [`BN_to_ASN1_INTEGER`]. Also see
+    /// [`BigNumRef::to_asn1_integer`].
+    ///
+    /// [`BN_to_ASN1_INTEGER`]: https://www.openssl.org/docs/manmaster/crypto/BN_to_ASN1_INTEGER.html
+    /// [`BigNumRef::to_asn1_integer`]: ../bn/struct.BigNumRef.html#method.to_asn1_integer
+    pub fn from_bn(bn: &BigNumRef) -> Result<Self, ErrorStack> {
+        bn.to_asn1_integer()
+    }
+}
+
+impl Ord for Asn1Integer {
+    fn cmp(&self, other: &Self) -> Ordering {
+        Asn1IntegerRef::cmp(self, other)
+    }
+}
+impl PartialOrd for Asn1Integer {
+    fn partial_cmp(&self, other: &Asn1Integer) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+impl Eq for Asn1Integer {}
+impl PartialEq for Asn1Integer {
+    fn eq(&self, other: &Asn1Integer) -> bool {
+        Asn1IntegerRef::eq(self, other)
+    }
+}
+
+impl Asn1IntegerRef {
+    #[allow(missing_docs, clippy::unnecessary_cast)]
+    #[deprecated(since = "0.10.6", note = "use to_bn instead")]
+    pub fn get(&self) -> i64 {
+        unsafe { ffi::ASN1_INTEGER_get(self.as_ptr()) as i64 }
+    }
+
+    /// Converts the integer to a `BigNum`.
+    #[corresponds(ASN1_INTEGER_to_BN)]
+    pub fn to_bn(&self) -> Result<BigNum, ErrorStack> {
+        unsafe {
+            cvt_p(ffi::ASN1_INTEGER_to_BN(self.as_ptr(), ptr::null_mut()))
+                .map(|p| BigNum::from_ptr(p))
+        }
+    }
+
+    /// Sets the ASN.1 value to the value of a signed 32-bit integer, for larger numbers
+    /// see [`bn`].
+    ///
+    /// [`bn`]: ../bn/struct.BigNumRef.html#method.to_asn1_integer
+    #[corresponds(ASN1_INTEGER_set)]
+    pub fn set(&mut self, value: i32) -> Result<(), ErrorStack> {
+        unsafe { cvt(ffi::ASN1_INTEGER_set(self.as_ptr(), value as c_long)).map(|_| ()) }
+    }
+
+    /// Creates a new Asn1Integer with the same value.
+    #[corresponds(ASN1_INTEGER_dup)]
+    pub fn to_owned(&self) -> Result<Asn1Integer, ErrorStack> {
+        unsafe { cvt_p(ffi::ASN1_INTEGER_dup(self.as_ptr())).map(|p| Asn1Integer::from_ptr(p)) }
+    }
+}
+
+impl Ord for Asn1IntegerRef {
+    fn cmp(&self, other: &Self) -> Ordering {
+        let res = unsafe { ffi::ASN1_INTEGER_cmp(self.as_ptr(), other.as_ptr()) };
+        res.cmp(&0)
+    }
+}
+impl PartialOrd for Asn1IntegerRef {
+    fn partial_cmp(&self, other: &Asn1IntegerRef) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+impl Eq for Asn1IntegerRef {}
+impl PartialEq for Asn1IntegerRef {
+    fn eq(&self, other: &Asn1IntegerRef) -> bool {
+        self.cmp(other) == Ordering::Equal
+    }
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_BIT_STRING;
+    fn drop = ffi::ASN1_BIT_STRING_free;
+    /// Sequence of bytes
+    ///
+    /// Asn1BitString is used in [`x509`] certificates for the signature.
+    /// The bit string acts as a collection of bytes.
+    ///
+    /// [`x509`]: ../x509/struct.X509.html#method.signature
+    pub struct Asn1BitString;
+    /// A reference to an [`Asn1BitString`].
+    pub struct Asn1BitStringRef;
+}
+
+impl Asn1BitStringRef {
+    /// Returns the Asn1BitString as a slice.
+    #[corresponds(ASN1_STRING_get0_data)]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { util::from_raw_parts(ASN1_STRING_get0_data(self.as_ptr() as *mut _), self.len()) }
+    }
+
+    /// Returns the number of bytes in the string.
+    #[corresponds(ASN1_STRING_length)]
+    pub fn len(&self) -> usize {
+        unsafe { ffi::ASN1_STRING_length(self.as_ptr() as *const _) as usize }
+    }
+
+    /// Determines if the string is empty.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_OCTET_STRING;
+    fn drop = ffi::ASN1_OCTET_STRING_free;
+    /// ASN.1 OCTET STRING type
+    pub struct Asn1OctetString;
+    /// A reference to an [`Asn1OctetString`].
+    pub struct Asn1OctetStringRef;
+}
+
+impl Asn1OctetString {
+    /// Creates an Asn1OctetString from bytes
+    pub fn new_from_bytes(value: &[u8]) -> Result<Self, ErrorStack> {
+        ffi::init();
+        unsafe {
+            let s = cvt_p(ffi::ASN1_OCTET_STRING_new())?;
+            ffi::ASN1_OCTET_STRING_set(s, value.as_ptr(), value.len().try_into().unwrap());
+            Ok(Self::from_ptr(s))
+        }
+    }
+}
+
+impl Asn1OctetStringRef {
+    /// Returns the octet string as an array of bytes.
+    #[corresponds(ASN1_STRING_get0_data)]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { util::from_raw_parts(ASN1_STRING_get0_data(self.as_ptr().cast()), self.len()) }
+    }
+
+    /// Returns the number of bytes in the octet string.
+    #[corresponds(ASN1_STRING_length)]
+    pub fn len(&self) -> usize {
+        unsafe { ffi::ASN1_STRING_length(self.as_ptr().cast()) as usize }
+    }
+
+    /// Determines if the string is empty.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_OBJECT;
+    fn drop = ffi::ASN1_OBJECT_free;
+    fn clone = ffi::OBJ_dup;
+
+    /// Object Identifier
+    ///
+    /// Represents an ASN.1 Object.  Typically, NIDs, or numeric identifiers
+    /// are stored as a table within the [`Nid`] module.  These constants are
+    /// used to determine attributes of a certificate, such as mapping the
+    /// attribute "CommonName" to "CN" which is represented as the OID of 13.
+    /// This attribute is a constant in the [`nid::COMMONNAME`].
+    ///
+    /// OpenSSL documentation at [`OBJ_nid2obj`]
+    ///
+    /// [`Nid`]: ../nid/index.html
+    /// [`nid::COMMONNAME`]: ../nid/constant.COMMONNAME.html
+    /// [`OBJ_nid2obj`]: https://www.openssl.org/docs/manmaster/crypto/OBJ_obj2nid.html
+    pub struct Asn1Object;
+    /// A reference to an [`Asn1Object`].
+    pub struct Asn1ObjectRef;
+}
+
+impl Stackable for Asn1Object {
+    type StackType = ffi::stack_st_ASN1_OBJECT;
+}
+
+impl Asn1Object {
+    /// Constructs an ASN.1 Object Identifier from a string representation of the OID.
+    #[corresponds(OBJ_txt2obj)]
+    #[allow(clippy::should_implement_trait)]
+    pub fn from_str(txt: &str) -> Result<Asn1Object, ErrorStack> {
+        unsafe {
+            ffi::init();
+            let txt = CString::new(txt).unwrap();
+            let obj: *mut ffi::ASN1_OBJECT = cvt_p(ffi::OBJ_txt2obj(txt.as_ptr() as *const _, 0))?;
+            Ok(Asn1Object::from_ptr(obj))
+        }
+    }
+
+    /// Return the OID as an DER encoded array of bytes. This is the ASN.1
+    /// value, not including tag or length.
+    ///
+    /// Requires OpenSSL 1.1.1 or newer.
+    #[corresponds(OBJ_get0_data)]
+    #[cfg(ossl111)]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe {
+            let len = ffi::OBJ_length(self.as_ptr());
+            util::from_raw_parts(ffi::OBJ_get0_data(self.as_ptr()), len)
+        }
+    }
+}
+
+impl Asn1ObjectRef {
+    /// Returns the NID associated with this OID.
+    pub fn nid(&self) -> Nid {
+        unsafe { Nid::from_raw(ffi::OBJ_obj2nid(self.as_ptr())) }
+    }
+}
+
+impl fmt::Display for Asn1ObjectRef {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        unsafe {
+            let mut buf = [0; 80];
+            let len = ffi::OBJ_obj2txt(
+                buf.as_mut_ptr() as *mut _,
+                buf.len() as c_int,
+                self.as_ptr(),
+                0,
+            );
+            match str::from_utf8(&buf[..len as usize]) {
+                Err(_) => fmt.write_str("error"),
+                Ok(s) => fmt.write_str(s),
+            }
+        }
+    }
+}
+
+impl fmt::Debug for Asn1ObjectRef {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt.write_str(self.to_string().as_str())
+    }
+}
+
+cfg_if! {
+    if #[cfg(any(ossl110, libressl273, boringssl))] {
+        use ffi::ASN1_STRING_get0_data;
+    } else {
+        #[allow(bad_style)]
+        unsafe fn ASN1_STRING_get0_data(s: *mut ffi::ASN1_STRING) -> *const ::libc::c_uchar {
+            ffi::ASN1_STRING_data(s)
+        }
+    }
+}
+
+foreign_type_and_impl_send_sync! {
+    type CType = ffi::ASN1_ENUMERATED;
+    fn drop = ffi::ASN1_ENUMERATED_free;
+
+    /// An ASN.1 enumerated.
+    pub struct Asn1Enumerated;
+    /// A reference to an [`Asn1Enumerated`].
+    pub struct Asn1EnumeratedRef;
+}
+
+impl Asn1EnumeratedRef {
+    /// Get the value, if it fits in the required bounds.
+    #[corresponds(ASN1_ENUMERATED_get_int64)]
+    #[cfg(ossl110)]
+    pub fn get_i64(&self) -> Result<i64, ErrorStack> {
+        let mut crl_reason = 0;
+        unsafe {
+            cvt(ffi::ASN1_ENUMERATED_get_int64(
+                &mut crl_reason,
+                self.as_ptr(),
+            ))?;
+        }
+        Ok(crl_reason)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use crate::bn::BigNum;
+    use crate::nid::Nid;
+
+    /// Tests conversion between BigNum and Asn1Integer.
+    #[test]
+    fn bn_cvt() {
+        fn roundtrip(bn: BigNum) {
+            let large = Asn1Integer::from_bn(&bn).unwrap();
+            assert_eq!(large.to_bn().unwrap(), bn);
+        }
+
+        roundtrip(BigNum::from_dec_str("1000000000000000000000000000000000").unwrap());
+        roundtrip(-BigNum::from_dec_str("1000000000000000000000000000000000").unwrap());
+        roundtrip(BigNum::from_u32(1234).unwrap());
+        roundtrip(-BigNum::from_u32(1234).unwrap());
+    }
+
+    #[test]
+    fn time_from_str() {
+        Asn1Time::from_str("99991231235959Z").unwrap();
+        #[cfg(ossl111)]
+        Asn1Time::from_str_x509("99991231235959Z").unwrap();
+    }
+
+    #[test]
+    fn time_from_unix() {
+        let t = Asn1Time::from_unix(0).unwrap();
+        assert_eq!("Jan  1 00:00:00 1970 GMT", t.to_string());
+    }
+
+    #[test]
+    #[cfg(any(ossl102, boringssl))]
+    fn time_eq() {
+        let a = Asn1Time::from_str("99991231235959Z").unwrap();
+        let b = Asn1Time::from_str("99991231235959Z").unwrap();
+        let c = Asn1Time::from_str("99991231235958Z").unwrap();
+        let a_ref = a.as_ref();
+        let b_ref = b.as_ref();
+        let c_ref = c.as_ref();
+        assert!(a == b);
+        assert!(a != c);
+        assert!(a == b_ref);
+        assert!(a != c_ref);
+        assert!(b_ref == a);
+        assert!(c_ref != a);
+        assert!(a_ref == b_ref);
+        assert!(a_ref != c_ref);
+    }
+
+    #[test]
+    #[cfg(any(ossl102, boringssl))]
+    fn time_ord() {
+        let a = Asn1Time::from_str("99991231235959Z").unwrap();
+        let b = Asn1Time::from_str("99991231235959Z").unwrap();
+        let c = Asn1Time::from_str("99991231235958Z").unwrap();
+        let a_ref = a.as_ref();
+        let b_ref = b.as_ref();
+        let c_ref = c.as_ref();
+        assert!(a >= b);
+        assert!(a > c);
+        assert!(b <= a);
+        assert!(c < a);
+
+        assert!(a_ref >= b);
+        assert!(a_ref > c);
+        assert!(b_ref <= a);
+        assert!(c_ref < a);
+
+        assert!(a >= b_ref);
+        assert!(a > c_ref);
+        assert!(b <= a_ref);
+        assert!(c < a_ref);
+
+        assert!(a_ref >= b_ref);
+        assert!(a_ref > c_ref);
+        assert!(b_ref <= a_ref);
+        assert!(c_ref < a_ref);
+    }
+
+    #[test]
+    fn integer_to_owned() {
+        let a = Asn1Integer::from_bn(&BigNum::from_dec_str("42").unwrap()).unwrap();
+        let b = a.to_owned().unwrap();
+        assert_eq!(
+            a.to_bn().unwrap().to_dec_str().unwrap().to_string(),
+            b.to_bn().unwrap().to_dec_str().unwrap().to_string(),
+        );
+        assert_ne!(a.as_ptr(), b.as_ptr());
+    }
+
+    #[test]
+    fn integer_cmp() {
+        let a = Asn1Integer::from_bn(&BigNum::from_dec_str("42").unwrap()).unwrap();
+        let b = Asn1Integer::from_bn(&BigNum::from_dec_str("42").unwrap()).unwrap();
+        let c = Asn1Integer::from_bn(&BigNum::from_dec_str("43").unwrap()).unwrap();
+        assert!(a == b);
+        assert!(a != c);
+        assert!(a < c);
+        assert!(c > b);
+    }
+
+    #[test]
+    fn object_from_str() {
+        let object = Asn1Object::from_str("2.16.840.1.101.3.4.2.1").unwrap();
+        assert_eq!(object.nid(), Nid::SHA256);
+    }
+
+    #[test]
+    fn object_from_str_with_invalid_input() {
+        Asn1Object::from_str("NOT AN OID")
+            .map(|object| object.to_string())
+            .expect_err("parsing invalid OID should fail");
+    }
+
+    #[test]
+    #[cfg(ossl111)]
+    fn object_to_slice() {
+        let object = Asn1Object::from_str("2.16.840.1.101.3.4.2.1").unwrap();
+        assert_eq!(
+            object.as_slice(),
+            &[0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01],
+        );
+    }
+
+    #[test]
+    fn asn1_octet_string() {
+        let octet_string = Asn1OctetString::new_from_bytes(b"hello world").unwrap();
+        assert_eq!(octet_string.as_slice(), b"hello world");
+        assert_eq!(octet_string.len(), 11);
+    }
+}