Struct openssl::dsa::DsaSig

pub struct DsaSig(/* private fields */);

Object representing DSA signature.

DSA signatures consist of two components: r and s.

Examples

use std::convert::TryInto;

use openssl::bn::BigNum;
use openssl::dsa::{Dsa, DsaSig};
use openssl::hash::MessageDigest;
use openssl::pkey::PKey;
use openssl::sign::{Signer, Verifier};

const TEST_DATA: &[u8] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
let dsa_ref = Dsa::generate(1024).unwrap();

let pub_key: PKey<_> = dsa_ref.clone().try_into().unwrap();
let priv_key: PKey<_> = dsa_ref.try_into().unwrap();

let mut signer = if let Ok(signer) = Signer::new(MessageDigest::sha256(), &priv_key) {
    signer
} else {
    // DSA signing is not supported (eg. BoringSSL)
    return;
};

signer.update(TEST_DATA).unwrap();

let signature = signer.sign_to_vec().unwrap();
// Parse DER-encoded DSA signature
let signature = DsaSig::from_der(&signature).unwrap();

// Extract components `r` and `s`
let r = BigNum::from_slice(&signature.r().to_vec()).unwrap();
let s = BigNum::from_slice(&signature.s().to_vec()).unwrap();

// Construct new DSA signature from components
let signature = DsaSig::from_private_components(r, s).unwrap();

// Serialize DSA signature to DER
let signature = signature.to_der().unwrap();

let mut verifier = Verifier::new(MessageDigest::sha256(), &pub_key).unwrap();
verifier.update(TEST_DATA).unwrap();
assert!(verifier.verify(&signature[..]).unwrap());

Implementations

impl DsaSig

pub fn from_private_components(r: BigNum, s: BigNum) -> Result<Self, ErrorStack>

Returns a new DsaSig by setting the r and s values associated with an DSA signature.

This corresponds to DSA_SIG_set0.

pub fn from_der(der: &[u8]) -> Result<DsaSig, ErrorStack>

Decodes a DER-encoded DSA signature.

This corresponds to d2i_DSA_SIG.

Methods from Deref<Target = DsaSigRef>

pub fn to_der(&self) -> Result<Vec<u8>, ErrorStack>

Serializes the DSA signature into a DER-encoded DSASignature structure.

This corresponds to i2d_DSA_SIG.

pub fn r(&self) -> &BigNumRef

Returns internal component r of an DsaSig.

This corresponds to DSA_SIG_get0.

pub fn s(&self) -> &BigNumRef

Returns internal component s of an DsaSig.

This corresponds to DSA_SIG_get0.

Trait Implementations

impl AsRef<DsaSigRef> for DsaSig

fn as_ref(&self) -> &DsaSigRef

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<DsaSigRef> for DsaSig

fn borrow(&self) -> &DsaSigRef

Immutably borrows from an owned value.

impl Debug for DsaSig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for DsaSig

type Target = DsaSigRef

The resulting type after dereferencing.

fn deref(&self) -> &DsaSigRef

Dereferences the value.

impl DerefMut for DsaSig

fn deref_mut(&mut self) -> &mut DsaSigRef

Mutably dereferences the value.

impl Drop for DsaSig

fn drop(&mut self)

Executes the destructor for this type.

impl ForeignType for DsaSig

type CType = DSA_SIG

The raw C type.

type Ref = DsaSigRef

The type representing a reference to this type.

unsafe fn from_ptr(ptr: *mut DSA_SIG) -> DsaSig

Constructs an instance of this type from its raw type.

fn as_ptr(&self) -> *mut DSA_SIG

Returns a raw pointer to the wrapped value.

impl Send for DsaSig

impl Sync for DsaSig