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rust-secp256k1/src/ffi.rs

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// Bitcoin secp256k1 bindings
// Written in 2014 by
// Dawid Ciężarkiewicz
// Andrew Poelstra
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//
//! # FFI bindings
//! Direct bindings to the underlying C library functions. These should
//! not be needed for most users.
use std::mem;
use std::hash;
use libc::{c_int, c_uchar, c_uint, c_void, size_t};
/// Flag for context to enable no precomputation
pub const SECP256K1_START_NONE: c_uint = (1 << 0) | 0;
/// Flag for context to enable verification precomputation
pub const SECP256K1_START_VERIFY: c_uint = (1 << 0) | (1 << 8);
/// Flag for context to enable signing precomputation
pub const SECP256K1_START_SIGN: c_uint = (1 << 0) | (1 << 9);
/// Flag for keys to indicate uncompressed serialization format
pub const SECP256K1_SER_UNCOMPRESSED: c_uint = (1 << 1) | 0;
/// Flag for keys to indicate compressed serialization format
pub const SECP256K1_SER_COMPRESSED: c_uint = (1 << 1) | (1 << 8);
/// A nonce generation function. Ordinary users of the library
/// never need to see this type; only if you need to control
/// nonce generation do you need to use it. I have deliberately
/// made this hard to do: you have to write your own wrapper
/// around the FFI functions to use it. And it's an unsafe type.
/// Nonces are generated deterministically by RFC6979 by
/// default; there should be no need to ever change this.
pub type NonceFn = unsafe extern "C" fn(nonce32: *mut c_uchar,
msg32: *const c_uchar,
key32: *const c_uchar,
algo16: *const c_uchar,
attempt: c_uint,
data: *const c_void);
/// Hash function to use to post-process an ECDH point to get
/// a shared secret.
pub type EcdhHashFn = unsafe extern "C" fn(
output: *mut c_uchar,
x: *const c_uchar,
y: *const c_uchar,
data: *const c_void,
);
/// A Secp256k1 context, containing various precomputed values and such
/// needed to do elliptic curve computations. If you create one of these
/// with `secp256k1_context_create` you MUST destroy it with
/// `secp256k1_context_destroy`, or else you will have a memory leak.
#[derive(Clone, Debug)]
#[repr(C)] pub struct Context(c_int);
/// Library-internal representation of a Secp256k1 public key
#[repr(C)]
pub struct PublicKey([c_uchar; 64]);
impl_array_newtype!(PublicKey, c_uchar, 64);
impl_raw_debug!(PublicKey);
impl PublicKey {
/// Create a new (zeroed) public key usable for the FFI interface
pub fn new() -> PublicKey { PublicKey([0; 64]) }
/// Create a new (uninitialized) public key usable for the FFI interface
pub unsafe fn blank() -> PublicKey { mem::uninitialized() }
}
impl hash::Hash for PublicKey {
fn hash<H: hash::Hasher>(&self, state: &mut H) {
state.write(&self.0)
}
}
/// Library-internal representation of a Secp256k1 signature
#[repr(C)]
pub struct Signature([c_uchar; 64]);
impl_array_newtype!(Signature, c_uchar, 64);
impl_raw_debug!(Signature);
/// Library-internal representation of a Secp256k1 signature + recovery ID
#[repr(C)]
pub struct RecoverableSignature([c_uchar; 65]);
impl_array_newtype!(RecoverableSignature, c_uchar, 65);
impl_raw_debug!(RecoverableSignature);
impl Signature {
/// Create a new (zeroed) signature usable for the FFI interface
pub fn new() -> Signature { Signature([0; 64]) }
/// Create a new (uninitialized) signature usable for the FFI interface
pub unsafe fn blank() -> Signature { mem::uninitialized() }
}
impl RecoverableSignature {
/// Create a new (zeroed) signature usable for the FFI interface
pub fn new() -> RecoverableSignature { RecoverableSignature([0; 65]) }
/// Create a new (uninitialized) signature usable for the FFI interface
pub unsafe fn blank() -> RecoverableSignature { mem::uninitialized() }
}
/// Library-internal representation of an ECDH shared secret
#[repr(C)]
pub struct SharedSecret([c_uchar; 32]);
impl_array_newtype!(SharedSecret, c_uchar, 32);
impl_raw_debug!(SharedSecret);
impl SharedSecret {
/// Create a new (zeroed) signature usable for the FFI interface
pub fn new() -> SharedSecret { SharedSecret([0; 32]) }
/// Create a new (uninitialized) signature usable for the FFI interface
pub unsafe fn blank() -> SharedSecret { mem::uninitialized() }
}
#[cfg(not(feature = "fuzztarget"))]
extern "C" {
/// Default ECDH hash function
pub static secp256k1_ecdh_hash_function_default: EcdhHashFn;
pub static secp256k1_nonce_function_rfc6979: NonceFn;
pub static secp256k1_nonce_function_default: NonceFn;
// Contexts
pub fn secp256k1_context_create(flags: c_uint) -> *mut Context;
pub fn secp256k1_context_clone(cx: *mut Context) -> *mut Context;
pub fn secp256k1_context_destroy(cx: *mut Context);
pub fn secp256k1_context_randomize(cx: *mut Context,
seed32: *const c_uchar)
-> c_int;
// TODO secp256k1_context_set_illegal_callback
// TODO secp256k1_context_set_error_callback
// (Actually, I don't really want these exposed; if either of these
// are ever triggered it indicates a bug in rust-secp256k1, since
// one goal is to use Rust's type system to eliminate all possible
// bad inputs.)
// Pubkeys
pub fn secp256k1_ec_pubkey_parse(cx: *const Context, pk: *mut PublicKey,
input: *const c_uchar, in_len: size_t)
-> c_int;
pub fn secp256k1_ec_pubkey_serialize(cx: *const Context, output: *mut c_uchar,
out_len: *mut size_t, pk: *const PublicKey,
compressed: c_uint)
-> c_int;
// Signatures
pub fn secp256k1_ecdsa_signature_parse_der(cx: *const Context, sig: *mut Signature,
input: *const c_uchar, in_len: size_t)
-> c_int;
pub fn secp256k1_ecdsa_signature_parse_compact(cx: *const Context, sig: *mut Signature,
input64: *const c_uchar)
-> c_int;
pub fn ecdsa_signature_parse_der_lax(cx: *const Context, sig: *mut Signature,
input: *const c_uchar, in_len: size_t)
-> c_int;
pub fn secp256k1_ecdsa_signature_serialize_der(cx: *const Context, output: *mut c_uchar,
out_len: *mut size_t, sig: *const Signature)
-> c_int;
pub fn secp256k1_ecdsa_signature_serialize_compact(cx: *const Context, output64: *const c_uchar,
sig: *const Signature)
-> c_int;
pub fn secp256k1_ecdsa_recoverable_signature_parse_compact(cx: *const Context, sig: *mut RecoverableSignature,
input64: *const c_uchar, recid: c_int)
-> c_int;
pub fn secp256k1_ecdsa_recoverable_signature_serialize_compact(cx: *const Context, output64: *const c_uchar,
recid: *mut c_int, sig: *const RecoverableSignature)
-> c_int;
pub fn secp256k1_ecdsa_recoverable_signature_convert(cx: *const Context, sig: *mut Signature,
input: *const RecoverableSignature)
-> c_int;
pub fn secp256k1_ecdsa_signature_normalize(cx: *const Context, out_sig: *mut Signature,
in_sig: *const Signature)
-> c_int;
// ECDSA
pub fn secp256k1_ecdsa_verify(cx: *const Context,
sig: *const Signature,
msg32: *const c_uchar,
pk: *const PublicKey)
-> c_int;
pub fn secp256k1_ecdsa_sign(cx: *const Context,
sig: *mut Signature,
msg32: *const c_uchar,
sk: *const c_uchar,
noncefn: NonceFn,
noncedata: *const c_void)
-> c_int;
pub fn secp256k1_ecdsa_sign_recoverable(cx: *const Context,
sig: *mut RecoverableSignature,
msg32: *const c_uchar,
sk: *const c_uchar,
noncefn: NonceFn,
noncedata: *const c_void)
-> c_int;
pub fn secp256k1_ecdsa_recover(cx: *const Context,
pk: *mut PublicKey,
sig: *const RecoverableSignature,
msg32: *const c_uchar)
-> c_int;
// EC
pub fn secp256k1_ec_seckey_verify(cx: *const Context,
sk: *const c_uchar) -> c_int;
pub fn secp256k1_ec_pubkey_create(cx: *const Context, pk: *mut PublicKey,
sk: *const c_uchar) -> c_int;
//TODO secp256k1_ec_privkey_export
//TODO secp256k1_ec_privkey_import
pub fn secp256k1_ec_privkey_tweak_add(cx: *const Context,
sk: *mut c_uchar,
tweak: *const c_uchar)
-> c_int;
pub fn secp256k1_ec_pubkey_tweak_add(cx: *const Context,
pk: *mut PublicKey,
tweak: *const c_uchar)
-> c_int;
pub fn secp256k1_ec_privkey_tweak_mul(cx: *const Context,
sk: *mut c_uchar,
tweak: *const c_uchar)
-> c_int;
pub fn secp256k1_ec_pubkey_tweak_mul(cx: *const Context,
pk: *mut PublicKey,
tweak: *const c_uchar)
-> c_int;
pub fn secp256k1_ec_pubkey_combine(cx: *const Context,
out: *mut PublicKey,
ins: *const *const PublicKey,
n: c_int)
-> c_int;
pub fn secp256k1_ecdh(
cx: *const Context,
output: *mut SharedSecret,
pubkey: *const PublicKey,
privkey: *const c_uchar,
hashfp: EcdhHashFn,
data: *mut c_void,
) -> c_int;
}
#[cfg(feature = "fuzztarget")]
mod fuzz_dummy {
use libc::{c_int, c_uchar, c_uint, c_void, size_t};
use ffi::*;
use std::ptr;
extern "C" {
pub static secp256k1_ecdh_hash_function_default: EcdhHashFn;
pub static secp256k1_nonce_function_rfc6979: NonceFn;
}
// Contexts
/// Creates a dummy context, tracking flags to ensure proper calling semantics
pub unsafe fn secp256k1_context_create(flags: c_uint) -> *mut Context {
let b = Box::new(Context(flags as i32));
Box::into_raw(b)
}
/// Copies a dummy context
pub unsafe fn secp256k1_context_clone(cx: *mut Context) -> *mut Context {
let b = Box::new(Context((*cx).0));
Box::into_raw(b)
}
/// Frees a dummy context
pub unsafe fn secp256k1_context_destroy(cx: *mut Context) {
Box::from_raw(cx);
}
/// Asserts that cx is properly initialized
pub unsafe fn secp256k1_context_randomize(cx: *mut Context,
_seed32: *const c_uchar)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
1
}
// TODO secp256k1_context_set_illegal_callback
// TODO secp256k1_context_set_error_callback
// (Actually, I don't really want these exposed; if either of these
// are ever triggered it indicates a bug in rust-secp256k1, since
// one goal is to use Rust's type system to eliminate all possible
// bad inputs.)
// Pubkeys
/// Parse 33/65 byte pubkey into PublicKey, losing compressed information
pub unsafe fn secp256k1_ec_pubkey_parse(cx: *const Context, pk: *mut PublicKey,
input: *const c_uchar, in_len: size_t)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
match in_len {
33 => {
if (*input.offset(1) > 0x7f && *input != 2) || (*input.offset(1) <= 0x7f && *input != 3) {
0
} else {
ptr::copy(input.offset(1), (*pk).0[0..32].as_mut_ptr(), 32);
ptr::copy(input.offset(1), (*pk).0[32..64].as_mut_ptr(), 32);
test_pk_validate(cx, pk)
}
},
65 => {
if *input != 4 && *input != 6 && *input != 7 {
0
} else {
ptr::copy(input.offset(1), (*pk).0.as_mut_ptr(), 64);
test_pk_validate(cx, pk)
}
},
_ => 0
}
}
/// Serialize PublicKey back to 33/65 byte pubkey
pub unsafe fn secp256k1_ec_pubkey_serialize(cx: *const Context, output: *mut c_uchar,
out_len: *mut size_t, pk: *const PublicKey,
compressed: c_uint)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if test_pk_validate(cx, pk) != 1 { return 0; }
if compressed == SECP256K1_SER_COMPRESSED {
assert_eq!(*out_len, 33);
if (*pk).0[0] > 0x7f {
*output = 2;
} else {
*output = 3;
}
ptr::copy((*pk).0.as_ptr(), output.offset(1), 32);
} else if compressed == SECP256K1_SER_UNCOMPRESSED {
assert_eq!(*out_len, 65);
*output = 4;
ptr::copy((*pk).0.as_ptr(), output.offset(1), 64);
} else {
panic!("Bad flags");
}
1
}
// Signatures
pub unsafe fn secp256k1_ecdsa_signature_parse_der(cx: *const Context, sig: *mut Signature,
input: *const c_uchar, in_len: size_t)
-> c_int {
unimplemented!();
}
/// Copies input64 to sig, checking the pubkey part is valid
pub unsafe fn secp256k1_ecdsa_signature_parse_compact(cx: *const Context, sig: *mut Signature,
input64: *const c_uchar)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if secp256k1_ec_seckey_verify(cx, input64.offset(32)) != 1 { return 0; } // sig should be msg32||sk
ptr::copy(input64, (*sig).0[..].as_mut_ptr(), 64);
1
}
pub unsafe fn ecdsa_signature_parse_der_lax(cx: *const Context, sig: *mut Signature,
input: *const c_uchar, in_len: size_t)
-> c_int {
unimplemented!();
}
/// Copies up to 72 bytes into output from sig
pub unsafe fn secp256k1_ecdsa_signature_serialize_der(cx: *const Context, output: *mut c_uchar,
out_len: *mut size_t, sig: *const Signature)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
let mut len_r = 33;
if *(*sig).0.as_ptr().offset(0) < 0x80 {
len_r -= 1;
}
let mut len_s = 33;
if *(*sig).0.as_ptr().offset(32) < 0x80 {
len_s -= 1;
}
assert!(*out_len >= (6 + len_s + len_r) as size_t);
*output.offset(0) = 0x30;
*output.offset(1) = 4 + len_r + len_s;
*output.offset(2) = 0x02;
*output.offset(3) = len_r;
if len_r == 33 {
*output.offset(4) = 0;
ptr::copy((*sig).0[..].as_ptr(), output.offset(5), 32);
} else {
ptr::copy((*sig).0[..].as_ptr(), output.offset(4), 32);
}
*output.offset(4 + len_r as isize) = 0x02;
*output.offset(5 + len_r as isize) = len_s;
if len_s == 33 {
*output.offset(6 + len_r as isize) = 0;
ptr::copy((*sig).0[..].as_ptr().offset(32), output.offset(7 + len_r as isize), 32);
} else {
ptr::copy((*sig).0[..].as_ptr().offset(32), output.offset(6 + len_r as isize), 32);
}
1
}
/// Copies sig to output64
pub unsafe fn secp256k1_ecdsa_signature_serialize_compact(cx: *const Context, output64: *mut c_uchar,
sig: *const Signature)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
ptr::copy((*sig).0[..].as_ptr(), output64, 64);
1
}
pub unsafe fn secp256k1_ecdsa_recoverable_signature_parse_compact(cx: *const Context, sig: *mut RecoverableSignature,
input64: *const c_uchar, recid: c_int)
-> c_int {
unimplemented!();
}
pub unsafe fn secp256k1_ecdsa_recoverable_signature_serialize_compact(cx: *const Context, output64: *const c_uchar,
recid: *mut c_int, sig: *const RecoverableSignature)
-> c_int {
unimplemented!();
}
pub unsafe fn secp256k1_ecdsa_recoverable_signature_convert(cx: *const Context, sig: *mut Signature,
input: *const RecoverableSignature)
-> c_int {
unimplemented!();
}
pub unsafe fn secp256k1_ecdsa_signature_normalize(cx: *const Context, out_sig: *mut Signature,
in_sig: *const Signature)
-> c_int {
unimplemented!();
}
// ECDSA
/// Verifies that sig is msg32||pk[0..32]
pub unsafe fn secp256k1_ecdsa_verify(cx: *const Context,
sig: *const Signature,
msg32: *const c_uchar,
pk: *const PublicKey)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
assert!((*cx).0 as u32 & SECP256K1_START_VERIFY == SECP256K1_START_VERIFY);
if test_pk_validate(cx, pk) != 1 { return 0; }
for i in 0..32 {
if (*sig).0[i] != *msg32.offset(i as isize) {
return 0;
}
}
if (*sig).0[32..64] != (*pk).0[0..32] {
0
} else {
1
}
}
/// Sets sig to msg32||sk
pub unsafe fn secp256k1_ecdsa_sign(cx: *const Context,
sig: *mut Signature,
msg32: *const c_uchar,
sk: *const c_uchar,
_noncefn: NonceFn,
_noncedata: *const c_void)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
assert!((*cx).0 as u32 & SECP256K1_START_SIGN == SECP256K1_START_SIGN);
if secp256k1_ec_seckey_verify(cx, sk) != 1 { return 0; }
ptr::copy(msg32, (*sig).0[0..32].as_mut_ptr(), 32);
ptr::copy(sk, (*sig).0[32..64].as_mut_ptr(), 32);
1
}
/// Sets sig to (2|3)||msg32||sk
pub unsafe fn secp256k1_ecdsa_sign_recoverable(cx: *const Context,
sig: *mut RecoverableSignature,
msg32: *const c_uchar,
sk: *const c_uchar,
_noncefn: NonceFn,
_noncedata: *const c_void)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
assert!((*cx).0 as u32 & SECP256K1_START_SIGN == SECP256K1_START_SIGN);
if secp256k1_ec_seckey_verify(cx, sk) != 1 { return 0; }
if *sk.offset(0) > 0x7f {
(*sig).0[0] = 2;
} else {
(*sig).0[0] = 3;
}
ptr::copy(msg32, (*sig).0[1..33].as_mut_ptr(), 32);
ptr::copy(sk, (*sig).0[33..65].as_mut_ptr(), 32);
1
}
pub unsafe fn secp256k1_ecdsa_recover(cx: *const Context,
pk: *mut PublicKey,
sig: *const RecoverableSignature,
msg32: *const c_uchar)
-> c_int {
unimplemented!();
}
// EC
/// Checks that pk != 0xffff...ffff and pk[0..32] == pk[32..64]
pub unsafe fn test_pk_validate(cx: *const Context,
pk: *const PublicKey) -> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if (*pk).0[0..32] != (*pk).0[32..64] || secp256k1_ec_seckey_verify(cx, (*pk).0[0..32].as_ptr()) == 0 {
0
} else {
1
}
}
/// Checks that sk != 0xffff...ffff
pub unsafe fn secp256k1_ec_seckey_verify(cx: *const Context,
sk: *const c_uchar) -> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
let mut res = 0;
for i in 0..32 {
if *sk.offset(i as isize) != 0xff { res = 1 };
}
res
}
/// Sets pk to sk||sk
pub unsafe fn secp256k1_ec_pubkey_create(cx: *const Context, pk: *mut PublicKey,
sk: *const c_uchar) -> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if secp256k1_ec_seckey_verify(cx, sk) != 1 { return 0; }
ptr::copy(sk, (*pk).0[0..32].as_mut_ptr(), 32);
ptr::copy(sk, (*pk).0[32..64].as_mut_ptr(), 32);
1
}
//TODO secp256k1_ec_privkey_export
//TODO secp256k1_ec_privkey_import
/// Copies the first 16 bytes of tweak into the last 16 bytes of sk
pub unsafe fn secp256k1_ec_privkey_tweak_add(cx: *const Context,
sk: *mut c_uchar,
tweak: *const c_uchar)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if secp256k1_ec_seckey_verify(cx, sk) != 1 { return 0; }
ptr::copy(tweak, sk.offset(16), 16);
*sk.offset(24) = 0x7f; // Ensure sk remains valid no matter what tweak was
1
}
/// The PublicKey equivalent of secp256k1_ec_privkey_tweak_add
pub unsafe fn secp256k1_ec_pubkey_tweak_add(cx: *const Context,
pk: *mut PublicKey,
tweak: *const c_uchar)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if test_pk_validate(cx, pk) != 1 { return 0; }
ptr::copy(tweak, (*pk).0[16..32].as_mut_ptr(), 16);
ptr::copy(tweak, (*pk).0[16+32..64].as_mut_ptr(), 16);
(*pk).0[24] = 0x7f; // Ensure pk remains valid no matter what tweak was
(*pk).0[24+32] = 0x7f; // Ensure pk remains valid no matter what tweak was
1
}
/// Copies the last 16 bytes of tweak into the last 16 bytes of sk
pub unsafe fn secp256k1_ec_privkey_tweak_mul(cx: *const Context,
sk: *mut c_uchar,
tweak: *const c_uchar)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if secp256k1_ec_seckey_verify(cx, sk) != 1 { return 0; }
ptr::copy(tweak.offset(16), sk.offset(16), 16);
*sk.offset(24) = 0x00; // Ensure sk remains valid no matter what tweak was
1
}
/// The PublicKey equivalent of secp256k1_ec_privkey_tweak_mul
pub unsafe fn secp256k1_ec_pubkey_tweak_mul(cx: *const Context,
pk: *mut PublicKey,
tweak: *const c_uchar)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
if test_pk_validate(cx, pk) != 1 { return 0; }
ptr::copy(tweak.offset(16), (*pk).0[16..32].as_mut_ptr(), 16);
ptr::copy(tweak.offset(16), (*pk).0[16+32..64].as_mut_ptr(), 16);
(*pk).0[24] = 0x00; // Ensure pk remains valid no matter what tweak was
(*pk).0[24+32] = 0x00; // Ensure pk remains valid no matter what tweak was
1
}
pub unsafe fn secp256k1_ec_pubkey_combine(cx: *const Context,
out: *mut PublicKey,
ins: *const *const PublicKey,
n: c_int)
-> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
assert!(n <= 32 && n >= 0); //TODO: Remove this restriction?
for i in 0..n {
if test_pk_validate(cx, *ins.offset(i as isize)) != 1 { return 0; }
(*out).0[(i*32/n) as usize..((i+1)*32/n) as usize].copy_from_slice(&(**ins.offset(i as isize)).0[(i*32/n) as usize..((i+1)*32/n) as usize]);
}
ptr::copy((*out).0[0..32].as_ptr(), (*out).0[32..64].as_mut_ptr(), 32);
(*out).0[24] = 0x0d; // pk should always be valid
(*out).0[24+32] = 0x0d; // pk should always be valid
test_pk_validate(cx, out)
}
/// Sets out to point[0..16]||scalar[0..16]
pub unsafe fn secp256k1_ecdh(
cx: *const Context,
out: *mut SharedSecret,
point: *const PublicKey,
scalar: *const c_uchar,
hashfp: EcdhHashFn,
data: *mut c_void,
) -> c_int {
assert!(!cx.is_null() && (*cx).0 as u32 & !(SECP256K1_START_NONE | SECP256K1_START_VERIFY | SECP256K1_START_SIGN) == 0);
assert!((*cx).0 as u32 & SECP256K1_START_SIGN == SECP256K1_START_SIGN);
if secp256k1_ec_seckey_verify(cx, scalar) != 1 { return 0; }
let mut scalar_prefix = [0; 16];
ptr::copy(scalar, scalar_prefix[..].as_mut_ptr(), 16);
if (*point).0[0..16] > scalar_prefix[0..16] {
(*out).0[0..16].copy_from_slice(&(*point).0[0..16]);
ptr::copy(scalar, (*out).0[16..32].as_mut_ptr(), 16);
} else {
ptr::copy(scalar, (*out).0[0..16].as_mut_ptr(), 16);
(*out).0[16..32].copy_from_slice(&(*point).0[0..16]);
}
(*out).0[16] = 0x00; // result should always be a valid secret key
1
}
}
#[cfg(feature = "fuzztarget")]
pub use self::fuzz_dummy::*;
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