//
// This file was automatically generated by witx-codegen - Do not edit manually.
//

#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum Error {
    WasiError(i32),
}
impl std::error::Error for Error {}
impl std::fmt::Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Error::WasiError(e) => write!(f, "Wasi error {}", e),
        }
    }
}

pub type WasiHandle = i32;
pub type Char8 = u8;
pub type Char32 = u32;
pub type WasiPtr<T> = *const T;
pub type WasiMutPtr<T> = *mut T;
pub type WasiStringBytesPtr = WasiPtr<Char8>;

#[repr(C)]
#[derive(Copy, Clone, Debug)]
pub struct WasiSlice<T> {
    ptr: WasiPtr<T>,
    len: usize,
}

#[repr(C)]
#[derive(Copy, Clone, Debug)]
pub struct WasiMutSlice<T> {
    ptr: WasiMutPtr<T>,
    len: usize,
}

impl<T> WasiSlice<T> {
    pub fn as_slice(&self) -> &[T] {
        unsafe { std::slice::from_raw_parts(self.ptr, self.len) }
    }

    pub fn from_slice(&self, slice: &[T]) -> Self {
        WasiSlice {
            ptr: slice.as_ptr() as _,
            len: slice.len(),
        }
    }
}

impl<T> WasiMutSlice<T> {
    pub fn as_slice(&self) -> &[T] {
        unsafe { std::slice::from_raw_parts(self.ptr, self.len) }
    }

    pub fn as_mut_slice(&self) -> &mut [T] {
        unsafe { std::slice::from_raw_parts_mut(self.ptr, self.len) }
    }

    pub fn from_slice(&self, slice: &[T]) -> Self {
        WasiMutSlice {
            ptr: slice.as_ptr() as _,
            len: slice.len(),
        }
    }

    pub fn from_mut_slice(&self, slice: &mut [T]) -> Self {
        WasiMutSlice {
            ptr: slice.as_mut_ptr(),
            len: slice.len(),
        }
    }
}

#[repr(C)]
#[derive(Copy, Clone, Debug)]
pub struct WasiString {
    ptr: WasiStringBytesPtr,
    len: usize,
}

impl<T: AsRef<str>> From<T> for WasiString {
    fn from(s: T) -> Self {
        let s = s.as_ref();
        WasiString {
            ptr: s.as_ptr() as _,
            len: s.len(),
        }
    }
}

impl WasiString {
    pub fn as_str(&self) -> Result<&str, std::str::Utf8Error> {
        std::str::from_utf8(unsafe { std::slice::from_raw_parts(self.ptr, self.len) })
    }

    pub fn as_slice(&self) -> &[u8] {
        unsafe { std::slice::from_raw_parts(self.ptr, self.len) }
    }

    pub fn from_slice(&self, slice: &[u8]) -> Self {
        WasiString {
            ptr: slice.as_ptr() as _,
            len: slice.len(),
        }
    }
}

// ---------------------- Module: [wasi_ephemeral_crypto_symmetric] ----------------------

/// Error codes.
pub type CryptoErrno = u16;

#[allow(non_snake_case)]
pub mod CRYPTO_ERRNO {
    use super::CryptoErrno;
    pub const SUCCESS: CryptoErrno = 0;
    pub const GUEST_ERROR: CryptoErrno = 1;
    pub const NOT_IMPLEMENTED: CryptoErrno = 2;
    pub const UNSUPPORTED_FEATURE: CryptoErrno = 3;
    pub const PROHIBITED_OPERATION: CryptoErrno = 4;
    pub const UNSUPPORTED_ENCODING: CryptoErrno = 5;
    pub const UNSUPPORTED_ALGORITHM: CryptoErrno = 6;
    pub const UNSUPPORTED_OPTION: CryptoErrno = 7;
    pub const INVALID_KEY: CryptoErrno = 8;
    pub const INVALID_LENGTH: CryptoErrno = 9;
    pub const VERIFICATION_FAILED: CryptoErrno = 10;
    pub const RNG_ERROR: CryptoErrno = 11;
    pub const ALGORITHM_FAILURE: CryptoErrno = 12;
    pub const INVALID_SIGNATURE: CryptoErrno = 13;
    pub const CLOSED: CryptoErrno = 14;
    pub const INVALID_HANDLE: CryptoErrno = 15;
    pub const OVERFLOW: CryptoErrno = 16;
    pub const INTERNAL_ERROR: CryptoErrno = 17;
    pub const TOO_MANY_HANDLES: CryptoErrno = 18;
    pub const KEY_NOT_SUPPORTED: CryptoErrno = 19;
    pub const KEY_REQUIRED: CryptoErrno = 20;
    pub const INVALID_TAG: CryptoErrno = 21;
    pub const INVALID_OPERATION: CryptoErrno = 22;
    pub const NONCE_REQUIRED: CryptoErrno = 23;
    pub const INVALID_NONCE: CryptoErrno = 24;
    pub const OPTION_NOT_SET: CryptoErrno = 25;
    pub const NOT_FOUND: CryptoErrno = 26;
    pub const PARAMETERS_MISSING: CryptoErrno = 27;
    pub const IN_PROGRESS: CryptoErrno = 28;
    pub const INCOMPATIBLE_KEYS: CryptoErrno = 29;
    pub const EXPIRED: CryptoErrno = 30;
}

/// Encoding to use for importing or exporting a key pair.
pub type KeypairEncoding = u16;

#[allow(non_snake_case)]
pub mod KEYPAIR_ENCODING {
    use super::KeypairEncoding;
    pub const RAW: KeypairEncoding = 0;
    pub const PKCS_8: KeypairEncoding = 1;
    pub const PEM: KeypairEncoding = 2;
    pub const LOCAL: KeypairEncoding = 3;
}

/// Encoding to use for importing or exporting a public key.
pub type PublickeyEncoding = u16;

#[allow(non_snake_case)]
pub mod PUBLICKEY_ENCODING {
    use super::PublickeyEncoding;
    pub const RAW: PublickeyEncoding = 0;
    pub const PKCS_8: PublickeyEncoding = 1;
    pub const PEM: PublickeyEncoding = 2;
    pub const SEC: PublickeyEncoding = 3;
    pub const COMPRESSED_SEC: PublickeyEncoding = 4;
    pub const LOCAL: PublickeyEncoding = 5;
}

/// Encoding to use for importing or exporting a secret key.
pub type SecretkeyEncoding = u16;

#[allow(non_snake_case)]
pub mod SECRETKEY_ENCODING {
    use super::SecretkeyEncoding;
    pub const RAW: SecretkeyEncoding = 0;
    pub const PKCS_8: SecretkeyEncoding = 1;
    pub const PEM: SecretkeyEncoding = 2;
    pub const SEC: SecretkeyEncoding = 3;
    pub const COMPRESSED_SEC: SecretkeyEncoding = 4;
    pub const LOCAL: SecretkeyEncoding = 5;
}

/// Encoding to use for importing or exporting a signature.
pub type SignatureEncoding = u16;

#[allow(non_snake_case)]
pub mod SIGNATURE_ENCODING {
    use super::SignatureEncoding;
    pub const RAW: SignatureEncoding = 0;
    pub const DER: SignatureEncoding = 1;
}

/// An algorithm category.
pub type AlgorithmType = u16;

#[allow(non_snake_case)]
pub mod ALGORITHM_TYPE {
    use super::AlgorithmType;
    pub const SIGNATURES: AlgorithmType = 0;
    pub const SYMMETRIC: AlgorithmType = 1;
    pub const KEY_EXCHANGE: AlgorithmType = 2;
}

/// Version of a managed key.
///
/// A version can be an arbitrary `u64` integer, with the expection of some reserved values.
pub type Version = u64;

/// Size of a value.
pub type Size = usize;

/// A UNIX timestamp, in seconds since 01/01/1970.
pub type Timestamp = u64;

/// A 64-bit value
pub type U64 = u64;

/// Handle for functions returning output whose size may be large or not known in advance.
///
/// An `array_output` object contains a host-allocated byte array.
///
/// A guest can get the size of that array after a function returns in order to then allocate a buffer of the correct size.
/// In addition, the content of such an object can be consumed by a guest in a streaming fashion.
///
/// An `array_output` handle is automatically closed after its full content has been consumed.
pub type ArrayOutput = WasiHandle;

/// A set of options.
///
/// This type is used to set non-default parameters.
///
/// The exact set of allowed options depends on the algorithm being used.
pub type Options = WasiHandle;

/// A handle to the optional secrets management facilities offered by a host.
///
/// This is used to generate, retrieve and invalidate managed keys.
pub type SecretsManager = WasiHandle;

/// A key pair.
pub type Keypair = WasiHandle;

/// A state to absorb data to be signed.
///
/// After a signature has been computed or verified, the state remains valid for further operations.
///
/// A subsequent signature would sign all the data accumulated since the creation of the state object.
pub type SignatureState = WasiHandle;

/// A signature.
pub type Signature = WasiHandle;

/// A public key, for key exchange and signature verification.
pub type Publickey = WasiHandle;

/// A secret key, for key exchange mechanisms.
pub type Secretkey = WasiHandle;

/// A state to absorb signed data to be verified.
pub type SignatureVerificationState = WasiHandle;

/// A state to perform symmetric operations.
///
/// The state is not reset nor invalidated after an option has been performed.
/// Incremental updates and sessions are thus supported.
pub type SymmetricState = WasiHandle;

/// A symmetric key.
///
/// The key can be imported from raw bytes, or can be a reference to a managed key.
///
/// If it was imported, the host will wipe it from memory as soon as the handle is closed.
pub type SymmetricKey = WasiHandle;

/// An authentication tag.
///
/// This is an object returned by functions computing authentication tags.
///
/// A tag can be compared against another tag (directly supplied as raw bytes) in constant time with the `symmetric_tag_verify()` function.
///
/// This object type can't be directly created from raw bytes. They are only returned by functions computing MACs.
///
/// The host is reponsible for securely wiping them from memory on close.
pub type SymmetricTag = WasiHandle;

/// Options index, only required by the Interface Types translation layer.
pub type OptOptionsU = u8;

#[allow(non_snake_case)]
pub mod OPT_OPTIONS_U {
    use super::OptOptionsU;
    pub const SOME: OptOptionsU = 0;
    pub const NONE: OptOptionsU = 1;
}

/// An optional options set.
///
/// This union simulates an `Option<Options>` type to make the `options` parameter of some functions optional.
#[repr(C)]
pub union OptOptionsMember {
    some: Options, // if tag=0
                   // none with no associated value if tag=1
}

#[repr(C, packed)]
pub struct OptOptions {
    pub tag: u8,
    __pad8_0: u8,
    __pad16_0: u16,
    __pad32_0: u32,
    pub member: std::mem::MaybeUninit<OptOptionsMember>,
}

impl OptOptions {
    fn new(tag: u8) -> Self {
        let mut tu = unsafe { std::mem::zeroed::<Self>() };
        tu.tag = tag;
        tu
    }

    // --- some: Options if tag=0

    pub fn new_some(val: Options) -> Self {
        let mut tu = Self::new(0);
        tu.member = std::mem::MaybeUninit::new(OptOptionsMember { some: val });
        tu
    }

    pub fn into_some(self) -> Options {
        assert_eq!(self.tag, 0);
        unsafe { self.member.assume_init().some }
    }

    pub fn set_some(&mut self, val: Options) {
        assert_eq!(self.tag, 0);
        let uval = OptOptionsMember { some: val };
        unsafe { *self.member.as_mut_ptr() = uval };
    }

    pub fn is_some(&self) -> bool {
        self.tag == 0
    }

    // --- none: (no associated content) if tag=1

    pub fn new_none() -> Self {
        Self::new(1)
    }

    pub fn is_none(&self) -> bool {
        self.tag == 1
    }
}

/// Symmetric key index, only required by the Interface Types translation layer.
pub type OptSymmetricKeyU = u8;

#[allow(non_snake_case)]
pub mod OPT_SYMMETRIC_KEY_U {
    use super::OptSymmetricKeyU;
    pub const SOME: OptSymmetricKeyU = 0;
    pub const NONE: OptSymmetricKeyU = 1;
}

/// An optional symmetric key.
///
/// This union simulates an `Option<SymmetricKey>` type to make the `symmetric_key` parameter of some functions optional.
#[repr(C)]
pub union OptSymmetricKeyMember {
    some: SymmetricKey, // if tag=0
                        // none with no associated value if tag=1
}

#[repr(C, packed)]
pub struct OptSymmetricKey {
    pub tag: u8,
    __pad8_0: u8,
    __pad16_0: u16,
    __pad32_0: u32,
    pub member: std::mem::MaybeUninit<OptSymmetricKeyMember>,
}

impl OptSymmetricKey {
    fn new(tag: u8) -> Self {
        let mut tu = unsafe { std::mem::zeroed::<Self>() };
        tu.tag = tag;
        tu
    }

    // --- some: SymmetricKey if tag=0

    pub fn new_some(val: SymmetricKey) -> Self {
        let mut tu = Self::new(0);
        tu.member = std::mem::MaybeUninit::new(OptSymmetricKeyMember { some: val });
        tu
    }

    pub fn into_some(self) -> SymmetricKey {
        assert_eq!(self.tag, 0);
        unsafe { self.member.assume_init().some }
    }

    pub fn set_some(&mut self, val: SymmetricKey) {
        assert_eq!(self.tag, 0);
        let uval = OptSymmetricKeyMember { some: val };
        unsafe { *self.member.as_mut_ptr() = uval };
    }

    pub fn is_some(&self) -> bool {
        self.tag == 0
    }

    // --- none: (no associated content) if tag=1

    pub fn new_none() -> Self {
        Self::new(1)
    }

    pub fn is_none(&self) -> bool {
        self.tag == 1
    }
}

/// Generate a new symmetric key for a given algorithm.
///
/// `options` can be `None` to use the default parameters, or an algoritm-specific set of parameters to override.
///
/// This function may return `unsupported_feature` if key generation is not supported by the host for the chosen algorithm, or `unsupported_algorithm` if the algorithm is not supported by the host.
pub fn symmetric_key_generate(
    algorithm_ptr: WasiPtr<Char8>,
    algorithm_len: usize,
    options: OptOptions,
) -> Result<SymmetricKey, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_generate(
            algorithm_ptr: WasiPtr<Char8>,
            algorithm_len: usize,
            options: OptOptions,
            result_ptr: WasiMutPtr<SymmetricKey>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_key_generate(
            algorithm_ptr,
            algorithm_len,
            options,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Create a symmetric key from raw material.
///
/// The algorithm is internally stored along with the key, and trying to use the key with an operation expecting a different algorithm will return `invalid_key`.
///
/// The function may also return `unsupported_algorithm` if the algorithm is not supported by the host.
pub fn symmetric_key_import(
    algorithm_ptr: WasiPtr<Char8>,
    algorithm_len: usize,
    raw: WasiPtr<u8>,
    raw_len: Size,
) -> Result<SymmetricKey, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_import(
            algorithm_ptr: WasiPtr<Char8>,
            algorithm_len: usize,
            raw: WasiPtr<u8>,
            raw_len: Size,
            result_ptr: WasiMutPtr<SymmetricKey>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_key_import(
            algorithm_ptr,
            algorithm_len,
            raw,
            raw_len,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Export a symmetric key as raw material.
///
/// This is mainly useful to export a managed key.
///
/// May return `prohibited_operation` if this operation is denied.
pub fn symmetric_key_export(symmetric_key: SymmetricKey) -> Result<ArrayOutput, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_export(
            symmetric_key: SymmetricKey,
            result_ptr: WasiMutPtr<ArrayOutput>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe { symmetric_key_export(symmetric_key, result_ptr.as_mut_ptr()) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Destroy a symmetric key.
///
/// Objects are reference counted. It is safe to close an object immediately after the last function needing it is called.
pub fn symmetric_key_close(symmetric_key: SymmetricKey) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_close(symmetric_key: SymmetricKey) -> CryptoErrno;
    }
    let res = unsafe { symmetric_key_close(symmetric_key) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// __(optional)__
/// Generate a new managed symmetric key.
///
/// The key is generated and stored by the secrets management facilities.
///
/// It may be used through its identifier, but the host may not allow it to be exported.
///
/// The function returns the `unsupported_feature` error code if secrets management facilities are not supported by the host,
/// or `unsupported_algorithm` if a key cannot be created for the chosen algorithm.
///
/// The function may also return `unsupported_algorithm` if the algorithm is not supported by the host.
///
/// This is also an optional import, meaning that the function may not even exist.
pub fn symmetric_key_generate_managed(
    secrets_manager: SecretsManager,
    algorithm_ptr: WasiPtr<Char8>,
    algorithm_len: usize,
    options: OptOptions,
) -> Result<SymmetricKey, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_generate_managed(
            secrets_manager: SecretsManager,
            algorithm_ptr: WasiPtr<Char8>,
            algorithm_len: usize,
            options: OptOptions,
            result_ptr: WasiMutPtr<SymmetricKey>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_key_generate_managed(
            secrets_manager,
            algorithm_ptr,
            algorithm_len,
            options,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// __(optional)__
/// Store a symmetric key into the secrets manager.
///
/// On success, the function stores the key identifier into `$symmetric_key_id`,
/// into which up to `$symmetric_key_id_max_len` can be written.
///
/// The function returns `overflow` if the supplied buffer is too small.
pub fn symmetric_key_store_managed(
    secrets_manager: SecretsManager,
    symmetric_key: SymmetricKey,
    symmetric_key_id: WasiMutPtr<u8>,
    symmetric_key_id_max_len: Size,
) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_store_managed(
            secrets_manager: SecretsManager,
            symmetric_key: SymmetricKey,
            symmetric_key_id: WasiMutPtr<u8>,
            symmetric_key_id_max_len: Size,
        ) -> CryptoErrno;
    }
    let res = unsafe {
        symmetric_key_store_managed(
            secrets_manager,
            symmetric_key,
            symmetric_key_id,
            symmetric_key_id_max_len,
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// __(optional)__
/// Replace a managed symmetric key.
///
/// This function crates a new version of a managed symmetric key, by replacing `$kp_old` with `$kp_new`.
///
/// It does several things:
///
/// - The key identifier for `$symmetric_key_new` is set to the one of `$symmetric_key_old`.
/// - A new, unique version identifier is assigned to `$kp_new`. This version will be equivalent to using `$version_latest` until the key is replaced.
/// - The `$symmetric_key_old` handle is closed.
///
/// Both keys must share the same algorithm and have compatible parameters. If this is not the case, `incompatible_keys` is returned.
///
/// The function may also return the `unsupported_feature` error code if secrets management facilities are not supported by the host,
/// or if keys cannot be rotated.
///
/// Finally, `prohibited_operation` can be returned if `$symmetric_key_new` wasn't created by the secrets manager, and the secrets manager prohibits imported keys.
///
/// If the operation succeeded, the new version is returned.
///
/// This is an optional import, meaning that the function may not even exist.
pub fn symmetric_key_replace_managed(
    secrets_manager: SecretsManager,
    symmetric_key_old: SymmetricKey,
    symmetric_key_new: SymmetricKey,
) -> Result<Version, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_replace_managed(
            secrets_manager: SecretsManager,
            symmetric_key_old: SymmetricKey,
            symmetric_key_new: SymmetricKey,
            result_ptr: WasiMutPtr<Version>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_key_replace_managed(
            secrets_manager,
            symmetric_key_old,
            symmetric_key_new,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// __(optional)__
/// Return the key identifier and version of a managed symmetric key.
///
/// If the key is not managed, `unsupported_feature` is returned instead.
///
/// This is an optional import, meaning that the function may not even exist.
pub fn symmetric_key_id(
    symmetric_key: SymmetricKey,
    symmetric_key_id: WasiMutPtr<u8>,
    symmetric_key_id_max_len: Size,
) -> Result<(Size, Version), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_id(
            symmetric_key: SymmetricKey,
            symmetric_key_id: WasiMutPtr<u8>,
            symmetric_key_id_max_len: Size,
            result_0_ptr: WasiMutPtr<Size>,
            result_1_ptr: WasiMutPtr<Version>,
        ) -> CryptoErrno;
    }
    let mut result_0_ptr = std::mem::MaybeUninit::uninit();
    let mut result_1_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_key_id(
            symmetric_key,
            symmetric_key_id,
            symmetric_key_id_max_len,
            result_0_ptr.as_mut_ptr(),
            result_1_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { (result_0_ptr.assume_init(), result_1_ptr.assume_init()) })
}

/// __(optional)__
/// Return a managed symmetric key from a key identifier.
///
/// `kp_version` can be set to `version_latest` to retrieve the most recent version of a symmetric key.
///
/// If no key matching the provided information is found, `not_found` is returned instead.
///
/// This is an optional import, meaning that the function may not even exist.
pub fn symmetric_key_from_id(
    secrets_manager: SecretsManager,
    symmetric_key_id: WasiPtr<u8>,
    symmetric_key_id_len: Size,
    symmetric_key_version: Version,
) -> Result<SymmetricKey, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_key_from_id(
            secrets_manager: SecretsManager,
            symmetric_key_id: WasiPtr<u8>,
            symmetric_key_id_len: Size,
            symmetric_key_version: Version,
            result_ptr: WasiMutPtr<SymmetricKey>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_key_from_id(
            secrets_manager,
            symmetric_key_id,
            symmetric_key_id_len,
            symmetric_key_version,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Create a new state to aborb and produce data using symmetric operations.
///
/// The state remains valid after every operation in order to support incremental updates.
///
/// The function has two optional parameters: a key and an options set.
///
/// It will fail with a `key_not_supported` error code if a key was provided but the chosen algorithm doesn't natively support keying.
///
/// On the other hand, if a key is required, but was not provided, a `key_required` error will be thrown.
///
/// Some algorithms may require additional parameters. They have to be supplied as an options set:
///
/// ```rust
/// let options_handle = ctx.options_open()?;
/// ctx.options_set("context", b"My application")?;
/// ctx.options_set_u64("fanout", 16)?;
/// let state_handle = ctx.symmetric_state_open("BLAKE2b-512", None, Some(options_handle))?;
/// ```
///
/// If some parameters are mandatory but were not set, the `parameters_missing` error code will be returned.
///
/// A notable exception is the `nonce` parameter, that is common to most AEAD constructions.
///
/// If a nonce is required but was not supplied:
///
/// - If it is safe to do so, the host will automatically generate a nonce. This is true for nonces that are large enough to be randomly generated, or if the host is able to maintain a global counter.
/// - If not, the function will fail and return the dedicated `nonce_required` error code.
///
/// A nonce that was automatically generated can be retrieved after the function returns with `symmetric_state_get(state_handle, "nonce")`.
///
/// **Sample usage patterns:**
///
/// - **Hashing**
///
/// ```rust
/// let mut out = [0u8; 64];
/// let state_handle = ctx.symmetric_state_open("SHAKE-128", None, None)?;
/// ctx.symmetric_state_absorb(state_handle, b"data")?;
/// ctx.symmetric_state_absorb(state_handle, b"more_data")?;
/// ctx.symmetric_state_squeeze(state_handle, &mut out)?;
/// ```
///
/// - **MAC**
///
/// ```rust
/// let mut raw_tag = [0u8; 64];
/// let key_handle = ctx.symmetric_key_import("HMAC/SHA-512", b"key")?;
/// let state_handle = ctx.symmetric_state_open("HMAC/SHA-512", Some(key_handle), None)?;
/// ctx.symmetric_state_absorb(state_handle, b"data")?;
/// ctx.symmetric_state_absorb(state_handle, b"more_data")?;
/// let computed_tag_handle = ctx.symmetric_state_squeeze_tag(state_handle)?;
/// ctx.symmetric_tag_pull(computed_tag_handle, &mut raw_tag)?;
/// ```
///
/// Verification:
///
/// ```rust
/// let state_handle = ctx.symmetric_state_open("HMAC/SHA-512", Some(key_handle), None)?;
/// ctx.symmetric_state_absorb(state_handle, b"data")?;
/// ctx.symmetric_state_absorb(state_handle, b"more_data")?;
/// let computed_tag_handle = ctx.symmetric_state_squeeze_tag(state_handle)?;
/// ctx.symmetric_tag_verify(computed_tag_handle, expected_raw_tag)?;
/// ```
///
/// - **Tuple hashing**
///
/// ```rust
/// let mut out = [0u8; 64];
/// let state_handle = ctx.symmetric_state_open("TupleHashXOF256", None, None)?;
/// ctx.symmetric_state_absorb(state_handle, b"value 1")?;
/// ctx.symmetric_state_absorb(state_handle, b"value 2")?;
/// ctx.symmetric_state_absorb(state_handle, b"value 3")?;
/// ctx.symmetric_state_squeeze(state_handle, &mut out)?;
/// ```
/// Unlike MACs and regular hash functions, inputs are domain separated instead of being concatenated.
///
/// - **Key derivation using extract-and-expand**
///
/// Extract:
///
/// ```rust
/// let mut prk = vec![0u8; 64];
/// let key_handle = ctx.symmetric_key_import("HKDF-EXTRACT/SHA-512", b"key")?;
/// let state_handle = ctx.symmetric_state_open("HKDF-EXTRACT/SHA-512", Some(key_handle), None)?;
/// ctx.symmetric_state_absorb(state_handle, b"salt")?;
/// let prk_handle = ctx.symmetric_state_squeeze_key(state_handle, "HKDF-EXPAND/SHA-512")?;
/// ```
///
/// Expand:
///
/// ```rust
/// let mut subkey = vec![0u8; 32];
/// let state_handle = ctx.symmetric_state_open("HKDF-EXPAND/SHA-512", Some(prk_handle), None)?;
/// ctx.symmetric_state_absorb(state_handle, b"info")?;
/// ctx.symmetric_state_squeeze(state_handle, &mut subkey)?;
/// ```
///
/// - **Key derivation using a XOF**
///
/// ```rust
/// let mut subkey1 = vec![0u8; 32];
/// let mut subkey2 = vec![0u8; 32];
/// let key_handle = ctx.symmetric_key_import("BLAKE3", b"key")?;
/// let state_handle = ctx.symmetric_state_open("BLAKE3", Some(key_handle), None)?;
/// ctx.symmetric_absorb(state_handle, b"context")?;
/// ctx.squeeze(state_handle, &mut subkey1)?;
/// ctx.squeeze(state_handle, &mut subkey2)?;
/// ```
///
/// - **Password hashing**
///
/// ```rust
/// let mut memory = vec![0u8; 1_000_000_000];
/// let options_handle = ctx.symmetric_options_open()?;
/// ctx.symmetric_options_set_guest_buffer(options_handle, "memory", &mut memory)?;
/// ctx.symmetric_options_set_u64(options_handle, "opslimit", 5)?;
/// ctx.symmetric_options_set_u64(options_handle, "parallelism", 8)?;
///
/// let state_handle = ctx.symmetric_state_open("ARGON2-ID-13", None, Some(options))?;
/// ctx.symmtric_state_absorb(state_handle, b"password")?;
///
/// let pw_str_handle = ctx.symmetric_state_squeeze_tag(state_handle)?;
/// let mut pw_str = vec![0u8; ctx.symmetric_tag_len(pw_str_handle)?];
/// ctx.symmetric_tag_pull(pw_str_handle, &mut pw_str)?;
/// ```
///
/// - **AEAD encryption with an explicit nonce**
///
/// ```rust
/// let key_handle = ctx.symmetric_key_generate("AES-256-GCM", None)?;
/// let message = b"test";
///
/// let options_handle = ctx.symmetric_options_open()?;
/// ctx.symmetric_options_set(options_handle, "nonce", nonce)?;
///
/// let state_handle = ctx.symmetric_state_open("AES-256-GCM", Some(key_handle), Some(options_handle))?;
/// let mut ciphertext = vec![0u8; message.len() + ctx.symmetric_state_max_tag_len(state_handle)?];
/// ctx.symmetric_state_absorb(state_handle, "additional data")?;
/// ctx.symmetric_state_encrypt(state_handle, &mut ciphertext, message)?;
/// ```
///
/// - **AEAD encryption with automatic nonce generation**
///
/// ```rust
/// let key_handle = ctx.symmetric_key_generate("AES-256-GCM-SIV", None)?;
/// let message = b"test";
/// let mut nonce = [0u8; 24];
///
/// let state_handle = ctx.symmetric_state_open("AES-256-GCM-SIV", Some(key_handle), None)?;
///
/// let nonce_handle = ctx.symmetric_state_options_get(state_handle, "nonce")?;
/// ctx.array_output_pull(nonce_handle, &mut nonce)?;
///
/// let mut ciphertext = vec![0u8; message.len() + ctx.symmetric_state_max_tag_len(state_handle)?];
/// ctx.symmetric_state_absorb(state_handle, "additional data")?;
/// ctx.symmetric_state_encrypt(state_handle, &mut ciphertext, message)?;
/// ```
///
/// - **Session authenticated modes**
///
/// ```rust
/// let mut out = [0u8; 16];
/// let mut out2 = [0u8; 16];
/// let mut ciphertext = [0u8; 20];
/// let key_handle = ctx.symmetric_key_generate("Xoodyak-128", None)?;
/// let state_handle = ctx.symmetric_state_open("Xoodyak-128", Some(key_handle), None)?;
/// ctx.symmetric_state_absorb(state_handle, b"data")?;
/// ctx.symmetric_state_encrypt(state_handle, &mut ciphertext, b"abcd")?;
/// ctx.symmetric_state_absorb(state_handle, b"more data")?;
/// ctx.symmetric_state_squeeze(state_handle, &mut out)?;
/// ctx.symmetric_state_squeeze(state_handle, &mut out2)?;
/// ctx.symmetric_state_ratchet(state_handle)?;
/// ctx.symmetric_state_absorb(state_handle, b"more data")?;
/// let next_key_handle = ctx.symmetric_state_squeeze_key(state_handle, "Xoodyak-128")?;
/// // ...
/// ```
pub fn symmetric_state_open(
    algorithm_ptr: WasiPtr<Char8>,
    algorithm_len: usize,
    key: OptSymmetricKey,
    options: OptOptions,
) -> Result<SymmetricState, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_open(
            algorithm_ptr: WasiPtr<Char8>,
            algorithm_len: usize,
            key: OptSymmetricKey,
            options: OptOptions,
            result_ptr: WasiMutPtr<SymmetricState>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_open(
            algorithm_ptr,
            algorithm_len,
            key,
            options,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Retrieve a parameter from the current state.
///
/// In particular, `symmetric_state_options_get("nonce")` can be used to get a nonce that as automatically generated.
///
/// The function may return `options_not_set` if an option was not set, which is different from an empty value.
///
/// It may also return `unsupported_option` if the option doesn't exist for the chosen algorithm.
pub fn symmetric_state_options_get(
    handle: SymmetricState,
    name_ptr: WasiPtr<Char8>,
    name_len: usize,
    value: WasiMutPtr<u8>,
    value_max_len: Size,
) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_options_get(
            handle: SymmetricState,
            name_ptr: WasiPtr<Char8>,
            name_len: usize,
            value: WasiMutPtr<u8>,
            value_max_len: Size,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_options_get(
            handle,
            name_ptr,
            name_len,
            value,
            value_max_len,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Retrieve an integer parameter from the current state.
///
/// In particular, `symmetric_state_options_get("nonce")` can be used to get a nonce that as automatically generated.
///
/// The function may return `options_not_set` if an option was not set.
///
/// It may also return `unsupported_option` if the option doesn't exist for the chosen algorithm.
pub fn symmetric_state_options_get_u_64(
    handle: SymmetricState,
    name_ptr: WasiPtr<Char8>,
    name_len: usize,
) -> Result<U64, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_options_get_u_64(
            handle: SymmetricState,
            name_ptr: WasiPtr<Char8>,
            name_len: usize,
            result_ptr: WasiMutPtr<U64>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_options_get_u_64(handle, name_ptr, name_len, result_ptr.as_mut_ptr())
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Destroy a symmetric state.
///
/// Objects are reference counted. It is safe to close an object immediately after the last function needing it is called.
pub fn symmetric_state_close(handle: SymmetricState) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_close(handle: SymmetricState) -> CryptoErrno;
    }
    let res = unsafe { symmetric_state_close(handle) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// Absorb data into the state.
///
/// - **Hash functions:** adds data to be hashed.
/// - **MAC functions:** adds data to be authenticated.
/// - **Tuplehash-like constructions:** adds a new tuple to the state.
/// - **Key derivation functions:** adds to the IKM or to the subkey information.
/// - **AEAD constructions:** adds additional data to be authenticated.
/// - **Stateful hash objects, permutation-based constructions:** absorbs.
///
/// If the chosen algorithm doesn't accept input data, the `invalid_operation` error code is returned.
///
/// If too much data has been fed for the algorithm, `overflow` may be thrown.
pub fn symmetric_state_absorb(
    handle: SymmetricState,
    data: WasiPtr<u8>,
    data_len: Size,
) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_absorb(
            handle: SymmetricState,
            data: WasiPtr<u8>,
            data_len: Size,
        ) -> CryptoErrno;
    }
    let res = unsafe { symmetric_state_absorb(handle, data, data_len) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// Squeeze bytes from the state.
///
/// - **Hash functions:** this tries to output an `out_len` bytes digest from the absorbed data. The hash function output will be truncated if necessary. If the requested size is too large, the `invalid_len` error code is returned.
/// - **Key derivation functions:** : outputs an arbitrary-long derived key.
/// - **RNGs, DRBGs, stream ciphers:**: outputs arbitrary-long data.
/// - **Stateful hash objects, permutation-based constructions:** squeeze.
///
/// Other kinds of algorithms may return `invalid_operation` instead.
///
/// For password-stretching functions, the function may return `in_progress`.
/// In that case, the guest should retry with the same parameters until the function completes.
pub fn symmetric_state_squeeze(
    handle: SymmetricState,
    out: WasiMutPtr<u8>,
    out_len: Size,
) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_squeeze(
            handle: SymmetricState,
            out: WasiMutPtr<u8>,
            out_len: Size,
        ) -> CryptoErrno;
    }
    let res = unsafe { symmetric_state_squeeze(handle, out, out_len) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// Compute and return a tag for all the data injected into the state so far.
///
/// - **MAC functions**: returns a tag authenticating the absorbed data.
/// - **Tuplehash-like constructions:** returns a tag authenticating all the absorbed tuples.
/// - **Password-hashing functions:** returns a standard string containing all the required parameters for password verification.
///
/// Other kinds of algorithms may return `invalid_operation` instead.
///
/// For password-stretching functions, the function may return `in_progress`.
/// In that case, the guest should retry with the same parameters until the function completes.
pub fn symmetric_state_squeeze_tag(handle: SymmetricState) -> Result<SymmetricTag, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_squeeze_tag(
            handle: SymmetricState,
            result_ptr: WasiMutPtr<SymmetricTag>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe { symmetric_state_squeeze_tag(handle, result_ptr.as_mut_ptr()) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Use the current state to produce a key for a target algorithm.
///
/// For extract-then-expand constructions, this returns the PRK.
/// For session-base authentication encryption, this returns a key that can be used to resume a session without storing a nonce.
///
/// `invalid_operation` is returned for algorithms not supporting this operation.
pub fn symmetric_state_squeeze_key(
    handle: SymmetricState,
    alg_str_ptr: WasiPtr<Char8>,
    alg_str_len: usize,
) -> Result<SymmetricKey, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_squeeze_key(
            handle: SymmetricState,
            alg_str_ptr: WasiPtr<Char8>,
            alg_str_len: usize,
            result_ptr: WasiMutPtr<SymmetricKey>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_squeeze_key(handle, alg_str_ptr, alg_str_len, result_ptr.as_mut_ptr())
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Return the maximum length of an authentication tag for the current algorithm.
///
/// This allows guests to compute the size required to store a ciphertext along with its authentication tag.
///
/// The returned length may include the encryption mode's padding requirements in addition to the actual tag.
///
/// For an encryption operation, the size of the output buffer should be `input_len + symmetric_state_max_tag_len()`.
///
/// For a decryption operation, the size of the buffer that will store the decrypted data must be `ciphertext_len - symmetric_state_max_tag_len()`.
pub fn symmetric_state_max_tag_len(handle: SymmetricState) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_max_tag_len(
            handle: SymmetricState,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe { symmetric_state_max_tag_len(handle, result_ptr.as_mut_ptr()) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Encrypt data with an attached tag.
///
/// - **Stream cipher:** adds the input to the stream cipher output. `out_len` and `data_len` can be equal, as no authentication tags will be added.
/// - **AEAD:** encrypts `data` into `out`, including the authentication tag to the output. Additional data must have been previously absorbed using `symmetric_state_absorb()`. The `symmetric_state_max_tag_len()` function can be used to retrieve the overhead of adding the tag, as well as padding if necessary.
/// - **SHOE, Xoodyak, Strobe:** encrypts data, squeezes a tag and appends it to the output.
///
/// If `out` and `data` are the same address, encryption may happen in-place.
///
/// The function returns the actual size of the ciphertext along with the tag.
///
/// `invalid_operation` is returned for algorithms not supporting encryption.
pub fn symmetric_state_encrypt(
    handle: SymmetricState,
    out: WasiMutPtr<u8>,
    out_len: Size,
    data: WasiPtr<u8>,
    data_len: Size,
) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_encrypt(
            handle: SymmetricState,
            out: WasiMutPtr<u8>,
            out_len: Size,
            data: WasiPtr<u8>,
            data_len: Size,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_encrypt(
            handle,
            out,
            out_len,
            data,
            data_len,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Encrypt data, with a detached tag.
///
/// - **Stream cipher:** returns `invalid_operation` since stream ciphers do not include authentication tags.
/// - **AEAD:** encrypts `data` into `out` and returns the tag separately. Additional data must have been previously absorbed using `symmetric_state_absorb()`. The output and input buffers must be of the same length.
/// - **SHOE, Xoodyak, Strobe:** encrypts data and squeezes a tag.
///
/// If `out` and `data` are the same address, encryption may happen in-place.
///
/// The function returns the tag.
///
/// `invalid_operation` is returned for algorithms not supporting encryption.
pub fn symmetric_state_encrypt_detached(
    handle: SymmetricState,
    out: WasiMutPtr<u8>,
    out_len: Size,
    data: WasiPtr<u8>,
    data_len: Size,
) -> Result<SymmetricTag, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_encrypt_detached(
            handle: SymmetricState,
            out: WasiMutPtr<u8>,
            out_len: Size,
            data: WasiPtr<u8>,
            data_len: Size,
            result_ptr: WasiMutPtr<SymmetricTag>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_encrypt_detached(
            handle,
            out,
            out_len,
            data,
            data_len,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// - **Stream cipher:** adds the input to the stream cipher output. `out_len` and `data_len` can be equal, as no authentication tags will be added.
/// - **AEAD:** decrypts `data` into `out`. Additional data must have been previously absorbed using `symmetric_state_absorb()`.
/// - **SHOE, Xoodyak, Strobe:** decrypts data, squeezes a tag and verify that it matches the one that was appended to the ciphertext.
///
/// If `out` and `data` are the same address, decryption may happen in-place.
///
/// `out_len` must be exactly `data_len` + `max_tag_len` bytes.
///
/// The function returns the actual size of the decrypted message, which can be smaller than `out_len` for modes that requires padding.
///
/// `invalid_tag` is returned if the tag didn't verify.
///
/// `invalid_operation` is returned for algorithms not supporting encryption.
pub fn symmetric_state_decrypt(
    handle: SymmetricState,
    out: WasiMutPtr<u8>,
    out_len: Size,
    data: WasiPtr<u8>,
    data_len: Size,
) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_decrypt(
            handle: SymmetricState,
            out: WasiMutPtr<u8>,
            out_len: Size,
            data: WasiPtr<u8>,
            data_len: Size,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_decrypt(
            handle,
            out,
            out_len,
            data,
            data_len,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// - **Stream cipher:** returns `invalid_operation` since stream ciphers do not include authentication tags.
/// - **AEAD:** decrypts `data` into `out`. Additional data must have been previously absorbed using `symmetric_state_absorb()`.
/// - **SHOE, Xoodyak, Strobe:** decrypts data, squeezes a tag and verify that it matches the expected one.
///
/// `raw_tag` is the expected tag, as raw bytes.
///
/// `out` and `data` be must have the same length.
/// If they also share the same address, decryption may happen in-place.
///
/// The function returns the actual size of the decrypted message.
///
/// `invalid_tag` is returned if the tag verification failed.
///
/// `invalid_operation` is returned for algorithms not supporting encryption.
pub fn symmetric_state_decrypt_detached(
    handle: SymmetricState,
    out: WasiMutPtr<u8>,
    out_len: Size,
    data: WasiPtr<u8>,
    data_len: Size,
    raw_tag: WasiPtr<u8>,
    raw_tag_len: Size,
) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_decrypt_detached(
            handle: SymmetricState,
            out: WasiMutPtr<u8>,
            out_len: Size,
            data: WasiPtr<u8>,
            data_len: Size,
            raw_tag: WasiPtr<u8>,
            raw_tag_len: Size,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe {
        symmetric_state_decrypt_detached(
            handle,
            out,
            out_len,
            data,
            data_len,
            raw_tag,
            raw_tag_len,
            result_ptr.as_mut_ptr(),
        )
    };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Make it impossible to recover the previous state.
///
/// This operation is supported by some systems keeping a rolling state over an entire session, for forward security.
///
/// `invalid_operation` is returned for algorithms not supporting ratcheting.
pub fn symmetric_state_ratchet(handle: SymmetricState) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_state_ratchet(handle: SymmetricState) -> CryptoErrno;
    }
    let res = unsafe { symmetric_state_ratchet(handle) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// Return the length of an authentication tag.
///
/// This function can be used by a guest to allocate the correct buffer size to copy a computed authentication tag.
pub fn symmetric_tag_len(symmetric_tag: SymmetricTag) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_tag_len(
            symmetric_tag: SymmetricTag,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe { symmetric_tag_len(symmetric_tag, result_ptr.as_mut_ptr()) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Copy an authentication tag into a guest-allocated buffer.
///
/// The handle automatically becomes invalid after this operation. Manually closing it is not required.
///
/// Example usage:
///
/// ```rust
/// let mut raw_tag = [0u8; 16];
/// ctx.symmetric_tag_pull(raw_tag_handle, &mut raw_tag)?;
/// ```
///
/// The function returns `overflow` if the supplied buffer is too small to copy the tag.
///
/// Otherwise, it returns the number of bytes that have been copied.
pub fn symmetric_tag_pull(
    symmetric_tag: SymmetricTag,
    buf: WasiMutPtr<u8>,
    buf_len: Size,
) -> Result<Size, Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_tag_pull(
            symmetric_tag: SymmetricTag,
            buf: WasiMutPtr<u8>,
            buf_len: Size,
            result_ptr: WasiMutPtr<Size>,
        ) -> CryptoErrno;
    }
    let mut result_ptr = std::mem::MaybeUninit::uninit();
    let res = unsafe { symmetric_tag_pull(symmetric_tag, buf, buf_len, result_ptr.as_mut_ptr()) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(unsafe { result_ptr.assume_init() })
}

/// Verify that a computed authentication tag matches the expected value, in constant-time.
///
/// The expected tag must be provided as a raw byte string.
///
/// The function returns `invalid_tag` if the tags don't match.
///
/// Example usage:
///
/// ```rust
/// let key_handle = ctx.symmetric_key_import("HMAC/SHA-256", b"key")?;
/// let state_handle = ctx.symmetric_state_open("HMAC/SHA-256", Some(key_handle), None)?;
/// ctx.symmetric_state_absorb(state_handle, b"data")?;
/// let computed_tag_handle = ctx.symmetric_state_squeeze_tag(state_handle)?;
/// ctx.symmetric_tag_verify(computed_tag_handle, expected_raw_tag)?;
/// ```
pub fn symmetric_tag_verify(
    symmetric_tag: SymmetricTag,
    expected_raw_tag_ptr: WasiPtr<u8>,
    expected_raw_tag_len: Size,
) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_tag_verify(
            symmetric_tag: SymmetricTag,
            expected_raw_tag_ptr: WasiPtr<u8>,
            expected_raw_tag_len: Size,
        ) -> CryptoErrno;
    }
    let res =
        unsafe { symmetric_tag_verify(symmetric_tag, expected_raw_tag_ptr, expected_raw_tag_len) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}

/// Explicitly destroy an unused authentication tag.
///
/// This is usually not necessary, as `symmetric_tag_pull()` automatically closes a tag after it has been copied.
///
/// Objects are reference counted. It is safe to close an object immediately after the last function needing it is called.
pub fn symmetric_tag_close(symmetric_tag: SymmetricTag) -> Result<(), Error> {
    #[link(wasm_import_module = "wasi_ephemeral_crypto_symmetric")]
    extern "C" {
        fn symmetric_tag_close(symmetric_tag: SymmetricTag) -> CryptoErrno;
    }
    let res = unsafe { symmetric_tag_close(symmetric_tag) };
    if res != 0 {
        return Err(Error::WasiError(res as _));
    }
    Ok(())
}