mirror of
https://github.com/hierynomus/sshj.git
synced 2025-12-06 23:30:55 +03:00
Replaced Curve25519 class with X25519 Key Agreement (#838)
Co-authored-by: Jeroen van Erp <jeroen@hierynomus.com>
This commit is contained in:
exceptionfactory
@@ -65,7 +65,6 @@ license {
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java = 'SLASHSTAR_STYLE'
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java = 'SLASHSTAR_STYLE'
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}
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}
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excludes([
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excludes([
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'**/djb/Curve25519.java',
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'**/sshj/common/Base64.java',
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'**/sshj/common/Base64.java',
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'**/com/hierynomus/sshj/userauth/keyprovider/bcrypt/*.java',
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'**/com/hierynomus/sshj/userauth/keyprovider/bcrypt/*.java',
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'**/files/test_file_*.txt',
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'**/files/test_file_*.txt',
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@@ -1,918 +0,0 @@
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/* Ported from C to Java by Dmitry Skiba [sahn0], 23/02/08.
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* Original: http://cds.xs4all.nl:8081/ecdh/
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*/
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/* Generic 64-bit integer implementation of Curve25519 ECDH
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* Written by Matthijs van Duin, 200608242056
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* Public domain.
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*
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* Based on work by Daniel J Bernstein, http://cr.yp.to/ecdh.html
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*/
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package djb;
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public class Curve25519 {
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/* key size */
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public static final int KEY_SIZE = 32;
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/* 0 */
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public static final byte[] ZERO = {
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
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};
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/* the prime 2^255-19 */
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public static final byte[] PRIME = {
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(byte)237, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)255,
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(byte)255, (byte)255, (byte)255, (byte)127
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};
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/* group order (a prime near 2^252+2^124) */
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public static final byte[] ORDER = {
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(byte)237, (byte)211, (byte)245, (byte)92,
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(byte)26, (byte)99, (byte)18, (byte)88,
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(byte)214, (byte)156, (byte)247, (byte)162,
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(byte)222, (byte)249, (byte)222, (byte)20,
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(byte)0, (byte)0, (byte)0, (byte)0,
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(byte)0, (byte)0, (byte)0, (byte)0,
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(byte)0, (byte)0, (byte)0, (byte)0,
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(byte)0, (byte)0, (byte)0, (byte)16
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};
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/********* KEY AGREEMENT *********/
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/* Private key clamping
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* k [out] your private key for key agreement
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* k [in] 32 random bytes
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*/
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public static final void clamp(byte[] k) {
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k[31] &= 0x7F;
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k[31] |= 0x40;
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k[ 0] &= 0xF8;
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}
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/* Key-pair generation
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* P [out] your public key
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* s [out] your private key for signing
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* k [out] your private key for key agreement
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* k [in] 32 random bytes
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* s may be NULL if you don't care
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*
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* WARNING: if s is not NULL, this function has data-dependent timing */
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public static final void keygen(byte[] P, byte[] s, byte[] k) {
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clamp(k);
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core(P, s, k, null);
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}
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/* Key agreement
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* Z [out] shared secret (needs hashing before use)
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* k [in] your private key for key agreement
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* P [in] peer's public key
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*/
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public static final void curve(byte[] Z, byte[] k, byte[] P) {
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core(Z, null, k, P);
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}
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/********* DIGITAL SIGNATURES *********/
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/* deterministic EC-KCDSA
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*
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* s is the private key for signing
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* P is the corresponding public key
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* Z is the context data (signer public key or certificate, etc)
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*
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* signing:
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*
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* m = hash(Z, message)
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* x = hash(m, s)
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* keygen25519(Y, NULL, x);
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* r = hash(Y);
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* h = m XOR r
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* sign25519(v, h, x, s);
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*
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* output (v,r) as the signature
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*
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* verification:
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*
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* m = hash(Z, message);
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* h = m XOR r
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* verify25519(Y, v, h, P)
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*
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* confirm r == hash(Y)
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*
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* It would seem to me that it would be simpler to have the signer directly do
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* h = hash(m, Y) and send that to the recipient instead of r, who can verify
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* the signature by checking h == hash(m, Y). If there are any problems with
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* such a scheme, please let me know.
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*
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* Also, EC-KCDSA (like most DS algorithms) picks x random, which is a waste of
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* perfectly good entropy, but does allow Y to be calculated in advance of (or
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* parallel to) hashing the message.
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*/
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/* Signature generation primitive, calculates (x-h)s mod q
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* v [out] signature value
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* h [in] signature hash (of message, signature pub key, and context data)
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* x [in] signature private key
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* s [in] private key for signing
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* returns true on success, false on failure (use different x or h)
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*/
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public static final boolean sign(byte[] v, byte[] h, byte[] x, byte[] s) {
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// v = (x - h) s mod q
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int w, i;
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byte[] h1 = new byte[32], x1 = new byte[32];
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byte[] tmp1 = new byte[64];
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byte[] tmp2 = new byte[64];
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// Don't clobber the arguments, be nice!
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cpy32(h1, h);
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cpy32(x1, x);
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// Reduce modulo group order
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byte[] tmp3=new byte[32];
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divmod(tmp3, h1, 32, ORDER, 32);
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divmod(tmp3, x1, 32, ORDER, 32);
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// v = x1 - h1
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// If v is negative, add the group order to it to become positive.
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// If v was already positive we don't have to worry about overflow
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// when adding the order because v < ORDER and 2*ORDER < 2^256
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mula_small(v, x1, 0, h1, 32, -1);
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mula_small(v, v , 0, ORDER, 32, 1);
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// tmp1 = (x-h)*s mod q
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mula32(tmp1, v, s, 32, 1);
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divmod(tmp2, tmp1, 64, ORDER, 32);
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for (w = 0, i = 0; i < 32; i++)
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w |= v[i] = tmp1[i];
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return w != 0;
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}
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/* Signature verification primitive, calculates Y = vP + hG
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* Y [out] signature public key
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* v [in] signature value
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* h [in] signature hash
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* P [in] public key
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*/
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public static final void verify(byte[] Y, byte[] v, byte[] h, byte[] P) {
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/* Y = v abs(P) + h G */
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byte[] d=new byte[32];
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long10[]
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p=new long10[]{new long10(),new long10()},
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s=new long10[]{new long10(),new long10()},
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yx=new long10[]{new long10(),new long10(),new long10()},
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yz=new long10[]{new long10(),new long10(),new long10()},
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t1=new long10[]{new long10(),new long10(),new long10()},
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t2=new long10[]{new long10(),new long10(),new long10()};
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int vi = 0, hi = 0, di = 0, nvh=0, i, j, k;
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/* set p[0] to G and p[1] to P */
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set(p[0], 9);
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unpack(p[1], P);
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/* set s[0] to P+G and s[1] to P-G */
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/* s[0] = (Py^2 + Gy^2 - 2 Py Gy)/(Px - Gx)^2 - Px - Gx - 486662 */
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/* s[1] = (Py^2 + Gy^2 + 2 Py Gy)/(Px - Gx)^2 - Px - Gx - 486662 */
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x_to_y2(t1[0], t2[0], p[1]); /* t2[0] = Py^2 */
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sqrt(t1[0], t2[0]); /* t1[0] = Py or -Py */
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j = is_negative(t1[0]); /* ... check which */
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t2[0]._0 += 39420360; /* t2[0] = Py^2 + Gy^2 */
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mul(t2[1], BASE_2Y, t1[0]);/* t2[1] = 2 Py Gy or -2 Py Gy */
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sub(t1[j], t2[0], t2[1]); /* t1[0] = Py^2 + Gy^2 - 2 Py Gy */
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add(t1[1-j], t2[0], t2[1]);/* t1[1] = Py^2 + Gy^2 + 2 Py Gy */
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cpy(t2[0], p[1]); /* t2[0] = Px */
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t2[0]._0 -= 9; /* t2[0] = Px - Gx */
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sqr(t2[1], t2[0]); /* t2[1] = (Px - Gx)^2 */
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recip(t2[0], t2[1], 0); /* t2[0] = 1/(Px - Gx)^2 */
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mul(s[0], t1[0], t2[0]); /* s[0] = t1[0]/(Px - Gx)^2 */
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sub(s[0], s[0], p[1]); /* s[0] = t1[0]/(Px - Gx)^2 - Px */
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s[0]._0 -= 9 + 486662; /* s[0] = X(P+G) */
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mul(s[1], t1[1], t2[0]); /* s[1] = t1[1]/(Px - Gx)^2 */
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sub(s[1], s[1], p[1]); /* s[1] = t1[1]/(Px - Gx)^2 - Px */
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s[1]._0 -= 9 + 486662; /* s[1] = X(P-G) */
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mul_small(s[0], s[0], 1); /* reduce s[0] */
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mul_small(s[1], s[1], 1); /* reduce s[1] */
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/* prepare the chain */
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for (i = 0; i < 32; i++) {
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vi = (vi >> 8) ^ (v[i] & 0xFF) ^ ((v[i] & 0xFF) << 1);
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hi = (hi >> 8) ^ (h[i] & 0xFF) ^ ((h[i] & 0xFF) << 1);
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nvh = ~(vi ^ hi);
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di = (nvh & (di & 0x80) >> 7) ^ vi;
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di ^= nvh & (di & 0x01) << 1;
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di ^= nvh & (di & 0x02) << 1;
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di ^= nvh & (di & 0x04) << 1;
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di ^= nvh & (di & 0x08) << 1;
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di ^= nvh & (di & 0x10) << 1;
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di ^= nvh & (di & 0x20) << 1;
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di ^= nvh & (di & 0x40) << 1;
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d[i] = (byte)di;
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}
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di = ((nvh & (di & 0x80) << 1) ^ vi) >> 8;
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/* initialize state */
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set(yx[0], 1);
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cpy(yx[1], p[di]);
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cpy(yx[2], s[0]);
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set(yz[0], 0);
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set(yz[1], 1);
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set(yz[2], 1);
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/* y[0] is (even)P + (even)G
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* y[1] is (even)P + (odd)G if current d-bit is 0
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* y[1] is (odd)P + (even)G if current d-bit is 1
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* y[2] is (odd)P + (odd)G
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*/
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vi = 0;
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hi = 0;
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/* and go for it! */
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for (i = 32; i--!=0; ) {
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vi = (vi << 8) | (v[i] & 0xFF);
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hi = (hi << 8) | (h[i] & 0xFF);
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di = (di << 8) | (d[i] & 0xFF);
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for (j = 8; j--!=0; ) {
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mont_prep(t1[0], t2[0], yx[0], yz[0]);
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mont_prep(t1[1], t2[1], yx[1], yz[1]);
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mont_prep(t1[2], t2[2], yx[2], yz[2]);
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k = ((vi ^ vi >> 1) >> j & 1)
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+ ((hi ^ hi >> 1) >> j & 1);
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mont_dbl(yx[2], yz[2], t1[k], t2[k], yx[0], yz[0]);
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k = (di >> j & 2) ^ ((di >> j & 1) << 1);
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mont_add(t1[1], t2[1], t1[k], t2[k], yx[1], yz[1],
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p[di >> j & 1]);
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mont_add(t1[2], t2[2], t1[0], t2[0], yx[2], yz[2],
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s[((vi ^ hi) >> j & 2) >> 1]);
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}
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}
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k = (vi & 1) + (hi & 1);
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recip(t1[0], yz[k], 0);
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mul(t1[1], yx[k], t1[0]);
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pack(t1[1], Y);
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}
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///////////////////////////////////////////////////////////////////////////
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/* sahn0:
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* Using this class instead of long[10] to avoid bounds checks. */
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private static final class long10 {
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public long10() {}
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public long10(
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long _0, long _1, long _2, long _3, long _4,
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long _5, long _6, long _7, long _8, long _9)
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{
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this._0=_0; this._1=_1; this._2=_2;
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this._3=_3; this._4=_4; this._5=_5;
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this._6=_6; this._7=_7; this._8=_8;
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this._9=_9;
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}
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public long _0,_1,_2,_3,_4,_5,_6,_7,_8,_9;
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}
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/********************* radix 2^8 math *********************/
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private static final void cpy32(byte[] d, byte[] s) {
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int i;
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for (i = 0; i < 32; i++)
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d[i] = s[i];
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}
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/* p[m..n+m-1] = q[m..n+m-1] + z * x */
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/* n is the size of x */
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/* n+m is the size of p and q */
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private static final int mula_small(byte[] p,byte[] q,int m,byte[] x,int n,int z) {
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int v=0;
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for (int i=0;i<n;++i) {
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v+=(q[i+m] & 0xFF)+z*(x[i] & 0xFF);
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p[i+m]=(byte)v;
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v>>=8;
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}
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return v;
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}
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/* p += x * y * z where z is a small integer
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* x is size 32, y is size t, p is size 32+t
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* y is allowed to overlap with p+32 if you don't care about the upper half */
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private static final int mula32(byte[] p, byte[] x, byte[] y, int t, int z) {
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final int n = 31;
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int w = 0;
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int i = 0;
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for (; i < t; i++) {
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int zy = z * (y[i] & 0xFF);
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w += mula_small(p, p, i, x, n, zy) +
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|
||||||
(p[i+n] & 0xFF) + zy * (x[n] & 0xFF);
|
|
||||||
p[i+n] = (byte)w;
|
|
||||||
w >>= 8;
|
|
||||||
}
|
|
||||||
p[i+n] = (byte)(w + (p[i+n] & 0xFF));
|
|
||||||
return w >> 8;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* divide r (size n) by d (size t), returning quotient q and remainder r
|
|
||||||
* quotient is size n-t+1, remainder is size t
|
|
||||||
* requires t > 0 && d[t-1] != 0
|
|
||||||
* requires that r[-1] and d[-1] are valid memory locations
|
|
||||||
* q may overlap with r+t */
|
|
||||||
private static final void divmod(byte[] q, byte[] r, int n, byte[] d, int t) {
|
|
||||||
int rn = 0;
|
|
||||||
int dt = ((d[t-1] & 0xFF) << 8);
|
|
||||||
if (t>1) {
|
|
||||||
dt |= (d[t-2] & 0xFF);
|
|
||||||
}
|
|
||||||
while (n-- >= t) {
|
|
||||||
int z = (rn << 16) | ((r[n] & 0xFF) << 8);
|
|
||||||
if (n>0) {
|
|
||||||
z |= (r[n-1] & 0xFF);
|
|
||||||
}
|
|
||||||
z/=dt;
|
|
||||||
rn += mula_small(r,r, n-t+1, d, t, -z);
|
|
||||||
q[n-t+1] = (byte)((z + rn) & 0xFF); /* rn is 0 or -1 (underflow) */
|
|
||||||
mula_small(r,r, n-t+1, d, t, -rn);
|
|
||||||
rn = (r[n] & 0xFF);
|
|
||||||
r[n] = 0;
|
|
||||||
}
|
|
||||||
r[t-1] = (byte)rn;
|
|
||||||
}
|
|
||||||
|
|
||||||
private static final int numsize(byte[] x,int n) {
|
|
||||||
while (n--!=0 && x[n]==0)
|
|
||||||
;
|
|
||||||
return n+1;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Returns x if a contains the gcd, y if b.
|
|
||||||
* Also, the returned buffer contains the inverse of a mod b,
|
|
||||||
* as 32-byte signed.
|
|
||||||
* x and y must have 64 bytes space for temporary use.
|
|
||||||
* requires that a[-1] and b[-1] are valid memory locations */
|
|
||||||
private static final byte[] egcd32(byte[] x,byte[] y,byte[] a,byte[] b) {
|
|
||||||
int an, bn = 32, qn, i;
|
|
||||||
for (i = 0; i < 32; i++)
|
|
||||||
x[i] = y[i] = 0;
|
|
||||||
x[0] = 1;
|
|
||||||
an = numsize(a, 32);
|
|
||||||
if (an==0)
|
|
||||||
return y; /* division by zero */
|
|
||||||
byte[] temp=new byte[32];
|
|
||||||
while (true) {
|
|
||||||
qn = bn - an + 1;
|
|
||||||
divmod(temp, b, bn, a, an);
|
|
||||||
bn = numsize(b, bn);
|
|
||||||
if (bn==0)
|
|
||||||
return x;
|
|
||||||
mula32(y, x, temp, qn, -1);
|
|
||||||
|
|
||||||
qn = an - bn + 1;
|
|
||||||
divmod(temp, a, an, b, bn);
|
|
||||||
an = numsize(a, an);
|
|
||||||
if (an==0)
|
|
||||||
return y;
|
|
||||||
mula32(x, y, temp, qn, -1);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/********************* radix 2^25.5 GF(2^255-19) math *********************/
|
|
||||||
|
|
||||||
private static final int P25=33554431; /* (1 << 25) - 1 */
|
|
||||||
private static final int P26=67108863; /* (1 << 26) - 1 */
|
|
||||||
|
|
||||||
/* Convert to internal format from little-endian byte format */
|
|
||||||
private static final void unpack(long10 x,byte[] m) {
|
|
||||||
x._0 = ((m[0] & 0xFF)) | ((m[1] & 0xFF))<<8 |
|
|
||||||
(m[2] & 0xFF)<<16 | ((m[3] & 0xFF)& 3)<<24;
|
|
||||||
x._1 = ((m[3] & 0xFF)&~ 3)>>2 | (m[4] & 0xFF)<<6 |
|
|
||||||
(m[5] & 0xFF)<<14 | ((m[6] & 0xFF)& 7)<<22;
|
|
||||||
x._2 = ((m[6] & 0xFF)&~ 7)>>3 | (m[7] & 0xFF)<<5 |
|
|
||||||
(m[8] & 0xFF)<<13 | ((m[9] & 0xFF)&31)<<21;
|
|
||||||
x._3 = ((m[9] & 0xFF)&~31)>>5 | (m[10] & 0xFF)<<3 |
|
|
||||||
(m[11] & 0xFF)<<11 | ((m[12] & 0xFF)&63)<<19;
|
|
||||||
x._4 = ((m[12] & 0xFF)&~63)>>6 | (m[13] & 0xFF)<<2 |
|
|
||||||
(m[14] & 0xFF)<<10 | (m[15] & 0xFF) <<18;
|
|
||||||
x._5 = (m[16] & 0xFF) | (m[17] & 0xFF)<<8 |
|
|
||||||
(m[18] & 0xFF)<<16 | ((m[19] & 0xFF)& 1)<<24;
|
|
||||||
x._6 = ((m[19] & 0xFF)&~ 1)>>1 | (m[20] & 0xFF)<<7 |
|
|
||||||
(m[21] & 0xFF)<<15 | ((m[22] & 0xFF)& 7)<<23;
|
|
||||||
x._7 = ((m[22] & 0xFF)&~ 7)>>3 | (m[23] & 0xFF)<<5 |
|
|
||||||
(m[24] & 0xFF)<<13 | ((m[25] & 0xFF)&15)<<21;
|
|
||||||
x._8 = ((m[25] & 0xFF)&~15)>>4 | (m[26] & 0xFF)<<4 |
|
|
||||||
(m[27] & 0xFF)<<12 | ((m[28] & 0xFF)&63)<<20;
|
|
||||||
x._9 = ((m[28] & 0xFF)&~63)>>6 | (m[29] & 0xFF)<<2 |
|
|
||||||
(m[30] & 0xFF)<<10 | (m[31] & 0xFF) <<18;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Check if reduced-form input >= 2^255-19 */
|
|
||||||
private static final boolean is_overflow(long10 x) {
|
|
||||||
return (
|
|
||||||
((x._0 > P26-19)) &&
|
|
||||||
((x._1 & x._3 & x._5 & x._7 & x._9) == P25) &&
|
|
||||||
((x._2 & x._4 & x._6 & x._8) == P26)
|
|
||||||
) || (x._9 > P25);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Convert from internal format to little-endian byte format. The
|
|
||||||
* number must be in a reduced form which is output by the following ops:
|
|
||||||
* unpack, mul, sqr
|
|
||||||
* set -- if input in range 0 .. P25
|
|
||||||
* If you're unsure if the number is reduced, first multiply it by 1. */
|
|
||||||
private static final void pack(long10 x,byte[] m) {
|
|
||||||
int ld = 0, ud = 0;
|
|
||||||
long t;
|
|
||||||
ld = (is_overflow(x)?1:0) - ((x._9 < 0)?1:0);
|
|
||||||
ud = ld * -(P25+1);
|
|
||||||
ld *= 19;
|
|
||||||
t = ld + x._0 + (x._1 << 26);
|
|
||||||
m[ 0] = (byte)t;
|
|
||||||
m[ 1] = (byte)(t >> 8);
|
|
||||||
m[ 2] = (byte)(t >> 16);
|
|
||||||
m[ 3] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + (x._2 << 19);
|
|
||||||
m[ 4] = (byte)t;
|
|
||||||
m[ 5] = (byte)(t >> 8);
|
|
||||||
m[ 6] = (byte)(t >> 16);
|
|
||||||
m[ 7] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + (x._3 << 13);
|
|
||||||
m[ 8] = (byte)t;
|
|
||||||
m[ 9] = (byte)(t >> 8);
|
|
||||||
m[10] = (byte)(t >> 16);
|
|
||||||
m[11] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + (x._4 << 6);
|
|
||||||
m[12] = (byte)t;
|
|
||||||
m[13] = (byte)(t >> 8);
|
|
||||||
m[14] = (byte)(t >> 16);
|
|
||||||
m[15] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + x._5 + (x._6 << 25);
|
|
||||||
m[16] = (byte)t;
|
|
||||||
m[17] = (byte)(t >> 8);
|
|
||||||
m[18] = (byte)(t >> 16);
|
|
||||||
m[19] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + (x._7 << 19);
|
|
||||||
m[20] = (byte)t;
|
|
||||||
m[21] = (byte)(t >> 8);
|
|
||||||
m[22] = (byte)(t >> 16);
|
|
||||||
m[23] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + (x._8 << 12);
|
|
||||||
m[24] = (byte)t;
|
|
||||||
m[25] = (byte)(t >> 8);
|
|
||||||
m[26] = (byte)(t >> 16);
|
|
||||||
m[27] = (byte)(t >> 24);
|
|
||||||
t = (t >> 32) + ((x._9 + ud) << 6);
|
|
||||||
m[28] = (byte)t;
|
|
||||||
m[29] = (byte)(t >> 8);
|
|
||||||
m[30] = (byte)(t >> 16);
|
|
||||||
m[31] = (byte)(t >> 24);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Copy a number */
|
|
||||||
private static final void cpy(long10 out, long10 in) {
|
|
||||||
out._0=in._0; out._1=in._1;
|
|
||||||
out._2=in._2; out._3=in._3;
|
|
||||||
out._4=in._4; out._5=in._5;
|
|
||||||
out._6=in._6; out._7=in._7;
|
|
||||||
out._8=in._8; out._9=in._9;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Set a number to value, which must be in range -185861411 .. 185861411 */
|
|
||||||
private static final void set(long10 out, int in) {
|
|
||||||
out._0=in; out._1=0;
|
|
||||||
out._2=0; out._3=0;
|
|
||||||
out._4=0; out._5=0;
|
|
||||||
out._6=0; out._7=0;
|
|
||||||
out._8=0; out._9=0;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Add/subtract two numbers. The inputs must be in reduced form, and the
|
|
||||||
* output isn't, so to do another addition or subtraction on the output,
|
|
||||||
* first multiply it by one to reduce it. */
|
|
||||||
private static final void add(long10 xy, long10 x, long10 y) {
|
|
||||||
xy._0 = x._0 + y._0; xy._1 = x._1 + y._1;
|
|
||||||
xy._2 = x._2 + y._2; xy._3 = x._3 + y._3;
|
|
||||||
xy._4 = x._4 + y._4; xy._5 = x._5 + y._5;
|
|
||||||
xy._6 = x._6 + y._6; xy._7 = x._7 + y._7;
|
|
||||||
xy._8 = x._8 + y._8; xy._9 = x._9 + y._9;
|
|
||||||
}
|
|
||||||
private static final void sub(long10 xy, long10 x, long10 y) {
|
|
||||||
xy._0 = x._0 - y._0; xy._1 = x._1 - y._1;
|
|
||||||
xy._2 = x._2 - y._2; xy._3 = x._3 - y._3;
|
|
||||||
xy._4 = x._4 - y._4; xy._5 = x._5 - y._5;
|
|
||||||
xy._6 = x._6 - y._6; xy._7 = x._7 - y._7;
|
|
||||||
xy._8 = x._8 - y._8; xy._9 = x._9 - y._9;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Multiply a number by a small integer in range -185861411 .. 185861411.
|
|
||||||
* The output is in reduced form, the input x need not be. x and xy may point
|
|
||||||
* to the same buffer. */
|
|
||||||
private static final long10 mul_small(long10 xy, long10 x, long y) {
|
|
||||||
long t;
|
|
||||||
t = (x._8*y);
|
|
||||||
xy._8 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x._9*y);
|
|
||||||
xy._9 = (t & ((1 << 25) - 1));
|
|
||||||
t = 19 * (t >> 25) + (x._0*y);
|
|
||||||
xy._0 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x._1*y);
|
|
||||||
xy._1 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x._2*y);
|
|
||||||
xy._2 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x._3*y);
|
|
||||||
xy._3 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x._4*y);
|
|
||||||
xy._4 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x._5*y);
|
|
||||||
xy._5 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x._6*y);
|
|
||||||
xy._6 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x._7*y);
|
|
||||||
xy._7 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + xy._8;
|
|
||||||
xy._8 = (t & ((1 << 26) - 1));
|
|
||||||
xy._9 += (t >> 26);
|
|
||||||
return xy;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Multiply two numbers. The output is in reduced form, the inputs need not
|
|
||||||
* be. */
|
|
||||||
private static final long10 mul(long10 xy, long10 x, long10 y) {
|
|
||||||
/* sahn0:
|
|
||||||
* Using local variables to avoid class access.
|
|
||||||
* This seem to improve performance a bit...
|
|
||||||
*/
|
|
||||||
long
|
|
||||||
x_0=x._0,x_1=x._1,x_2=x._2,x_3=x._3,x_4=x._4,
|
|
||||||
x_5=x._5,x_6=x._6,x_7=x._7,x_8=x._8,x_9=x._9;
|
|
||||||
long
|
|
||||||
y_0=y._0,y_1=y._1,y_2=y._2,y_3=y._3,y_4=y._4,
|
|
||||||
y_5=y._5,y_6=y._6,y_7=y._7,y_8=y._8,y_9=y._9;
|
|
||||||
long t;
|
|
||||||
t = (x_0*y_8) + (x_2*y_6) + (x_4*y_4) + (x_6*y_2) +
|
|
||||||
(x_8*y_0) + 2 * ((x_1*y_7) + (x_3*y_5) +
|
|
||||||
(x_5*y_3) + (x_7*y_1)) + 38 *
|
|
||||||
(x_9*y_9);
|
|
||||||
xy._8 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x_0*y_9) + (x_1*y_8) + (x_2*y_7) +
|
|
||||||
(x_3*y_6) + (x_4*y_5) + (x_5*y_4) +
|
|
||||||
(x_6*y_3) + (x_7*y_2) + (x_8*y_1) +
|
|
||||||
(x_9*y_0);
|
|
||||||
xy._9 = (t & ((1 << 25) - 1));
|
|
||||||
t = (x_0*y_0) + 19 * ((t >> 25) + (x_2*y_8) + (x_4*y_6)
|
|
||||||
+ (x_6*y_4) + (x_8*y_2)) + 38 *
|
|
||||||
((x_1*y_9) + (x_3*y_7) + (x_5*y_5) +
|
|
||||||
(x_7*y_3) + (x_9*y_1));
|
|
||||||
xy._0 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x_0*y_1) + (x_1*y_0) + 19 * ((x_2*y_9)
|
|
||||||
+ (x_3*y_8) + (x_4*y_7) + (x_5*y_6) +
|
|
||||||
(x_6*y_5) + (x_7*y_4) + (x_8*y_3) +
|
|
||||||
(x_9*y_2));
|
|
||||||
xy._1 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x_0*y_2) + (x_2*y_0) + 19 * ((x_4*y_8)
|
|
||||||
+ (x_6*y_6) + (x_8*y_4)) + 2 * (x_1*y_1)
|
|
||||||
+ 38 * ((x_3*y_9) + (x_5*y_7) +
|
|
||||||
(x_7*y_5) + (x_9*y_3));
|
|
||||||
xy._2 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x_0*y_3) + (x_1*y_2) + (x_2*y_1) +
|
|
||||||
(x_3*y_0) + 19 * ((x_4*y_9) + (x_5*y_8) +
|
|
||||||
(x_6*y_7) + (x_7*y_6) +
|
|
||||||
(x_8*y_5) + (x_9*y_4));
|
|
||||||
xy._3 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x_0*y_4) + (x_2*y_2) + (x_4*y_0) + 19 *
|
|
||||||
((x_6*y_8) + (x_8*y_6)) + 2 * ((x_1*y_3) +
|
|
||||||
(x_3*y_1)) + 38 *
|
|
||||||
((x_5*y_9) + (x_7*y_7) + (x_9*y_5));
|
|
||||||
xy._4 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x_0*y_5) + (x_1*y_4) + (x_2*y_3) +
|
|
||||||
(x_3*y_2) + (x_4*y_1) + (x_5*y_0) + 19 *
|
|
||||||
((x_6*y_9) + (x_7*y_8) + (x_8*y_7) +
|
|
||||||
(x_9*y_6));
|
|
||||||
xy._5 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x_0*y_6) + (x_2*y_4) + (x_4*y_2) +
|
|
||||||
(x_6*y_0) + 19 * (x_8*y_8) + 2 * ((x_1*y_5) +
|
|
||||||
(x_3*y_3) + (x_5*y_1)) + 38 *
|
|
||||||
((x_7*y_9) + (x_9*y_7));
|
|
||||||
xy._6 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + (x_0*y_7) + (x_1*y_6) + (x_2*y_5) +
|
|
||||||
(x_3*y_4) + (x_4*y_3) + (x_5*y_2) +
|
|
||||||
(x_6*y_1) + (x_7*y_0) + 19 * ((x_8*y_9) +
|
|
||||||
(x_9*y_8));
|
|
||||||
xy._7 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + xy._8;
|
|
||||||
xy._8 = (t & ((1 << 26) - 1));
|
|
||||||
xy._9 += (t >> 26);
|
|
||||||
return xy;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Square a number. Optimization of mul25519(x2, x, x) */
|
|
||||||
private static final long10 sqr(long10 x2, long10 x) {
|
|
||||||
long
|
|
||||||
x_0=x._0,x_1=x._1,x_2=x._2,x_3=x._3,x_4=x._4,
|
|
||||||
x_5=x._5,x_6=x._6,x_7=x._7,x_8=x._8,x_9=x._9;
|
|
||||||
long t;
|
|
||||||
t = (x_4*x_4) + 2 * ((x_0*x_8) + (x_2*x_6)) + 38 *
|
|
||||||
(x_9*x_9) + 4 * ((x_1*x_7) + (x_3*x_5));
|
|
||||||
x2._8 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + 2 * ((x_0*x_9) + (x_1*x_8) + (x_2*x_7) +
|
|
||||||
(x_3*x_6) + (x_4*x_5));
|
|
||||||
x2._9 = (t & ((1 << 25) - 1));
|
|
||||||
t = 19 * (t >> 25) + (x_0*x_0) + 38 * ((x_2*x_8) +
|
|
||||||
(x_4*x_6) + (x_5*x_5)) + 76 * ((x_1*x_9)
|
|
||||||
+ (x_3*x_7));
|
|
||||||
x2._0 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + 2 * (x_0*x_1) + 38 * ((x_2*x_9) +
|
|
||||||
(x_3*x_8) + (x_4*x_7) + (x_5*x_6));
|
|
||||||
x2._1 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + 19 * (x_6*x_6) + 2 * ((x_0*x_2) +
|
|
||||||
(x_1*x_1)) + 38 * (x_4*x_8) + 76 *
|
|
||||||
((x_3*x_9) + (x_5*x_7));
|
|
||||||
x2._2 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + 2 * ((x_0*x_3) + (x_1*x_2)) + 38 *
|
|
||||||
((x_4*x_9) + (x_5*x_8) + (x_6*x_7));
|
|
||||||
x2._3 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + (x_2*x_2) + 2 * (x_0*x_4) + 38 *
|
|
||||||
((x_6*x_8) + (x_7*x_7)) + 4 * (x_1*x_3) + 76 *
|
|
||||||
(x_5*x_9);
|
|
||||||
x2._4 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + 2 * ((x_0*x_5) + (x_1*x_4) + (x_2*x_3))
|
|
||||||
+ 38 * ((x_6*x_9) + (x_7*x_8));
|
|
||||||
x2._5 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + 19 * (x_8*x_8) + 2 * ((x_0*x_6) +
|
|
||||||
(x_2*x_4) + (x_3*x_3)) + 4 * (x_1*x_5) +
|
|
||||||
76 * (x_7*x_9);
|
|
||||||
x2._6 = (t & ((1 << 26) - 1));
|
|
||||||
t = (t >> 26) + 2 * ((x_0*x_7) + (x_1*x_6) + (x_2*x_5) +
|
|
||||||
(x_3*x_4)) + 38 * (x_8*x_9);
|
|
||||||
x2._7 = (t & ((1 << 25) - 1));
|
|
||||||
t = (t >> 25) + x2._8;
|
|
||||||
x2._8 = (t & ((1 << 26) - 1));
|
|
||||||
x2._9 += (t >> 26);
|
|
||||||
return x2;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Calculates a reciprocal. The output is in reduced form, the inputs need not
|
|
||||||
* be. Simply calculates y = x^(p-2) so it's not too fast. */
|
|
||||||
/* When sqrtassist is true, it instead calculates y = x^((p-5)/8) */
|
|
||||||
private static final void recip(long10 y, long10 x, int sqrtassist) {
|
|
||||||
long10
|
|
||||||
t0=new long10(),
|
|
||||||
t1=new long10(),
|
|
||||||
t2=new long10(),
|
|
||||||
t3=new long10(),
|
|
||||||
t4=new long10();
|
|
||||||
int i;
|
|
||||||
/* the chain for x^(2^255-21) is straight from djb's implementation */
|
|
||||||
sqr(t1, x); /* 2 == 2 * 1 */
|
|
||||||
sqr(t2, t1); /* 4 == 2 * 2 */
|
|
||||||
sqr(t0, t2); /* 8 == 2 * 4 */
|
|
||||||
mul(t2, t0, x); /* 9 == 8 + 1 */
|
|
||||||
mul(t0, t2, t1); /* 11 == 9 + 2 */
|
|
||||||
sqr(t1, t0); /* 22 == 2 * 11 */
|
|
||||||
mul(t3, t1, t2); /* 31 == 22 + 9
|
|
||||||
== 2^5 - 2^0 */
|
|
||||||
sqr(t1, t3); /* 2^6 - 2^1 */
|
|
||||||
sqr(t2, t1); /* 2^7 - 2^2 */
|
|
||||||
sqr(t1, t2); /* 2^8 - 2^3 */
|
|
||||||
sqr(t2, t1); /* 2^9 - 2^4 */
|
|
||||||
sqr(t1, t2); /* 2^10 - 2^5 */
|
|
||||||
mul(t2, t1, t3); /* 2^10 - 2^0 */
|
|
||||||
sqr(t1, t2); /* 2^11 - 2^1 */
|
|
||||||
sqr(t3, t1); /* 2^12 - 2^2 */
|
|
||||||
for (i = 1; i < 5; i++) {
|
|
||||||
sqr(t1, t3);
|
|
||||||
sqr(t3, t1);
|
|
||||||
} /* t3 */ /* 2^20 - 2^10 */
|
|
||||||
mul(t1, t3, t2); /* 2^20 - 2^0 */
|
|
||||||
sqr(t3, t1); /* 2^21 - 2^1 */
|
|
||||||
sqr(t4, t3); /* 2^22 - 2^2 */
|
|
||||||
for (i = 1; i < 10; i++) {
|
|
||||||
sqr(t3, t4);
|
|
||||||
sqr(t4, t3);
|
|
||||||
} /* t4 */ /* 2^40 - 2^20 */
|
|
||||||
mul(t3, t4, t1); /* 2^40 - 2^0 */
|
|
||||||
for (i = 0; i < 5; i++) {
|
|
||||||
sqr(t1, t3);
|
|
||||||
sqr(t3, t1);
|
|
||||||
} /* t3 */ /* 2^50 - 2^10 */
|
|
||||||
mul(t1, t3, t2); /* 2^50 - 2^0 */
|
|
||||||
sqr(t2, t1); /* 2^51 - 2^1 */
|
|
||||||
sqr(t3, t2); /* 2^52 - 2^2 */
|
|
||||||
for (i = 1; i < 25; i++) {
|
|
||||||
sqr(t2, t3);
|
|
||||||
sqr(t3, t2);
|
|
||||||
} /* t3 */ /* 2^100 - 2^50 */
|
|
||||||
mul(t2, t3, t1); /* 2^100 - 2^0 */
|
|
||||||
sqr(t3, t2); /* 2^101 - 2^1 */
|
|
||||||
sqr(t4, t3); /* 2^102 - 2^2 */
|
|
||||||
for (i = 1; i < 50; i++) {
|
|
||||||
sqr(t3, t4);
|
|
||||||
sqr(t4, t3);
|
|
||||||
} /* t4 */ /* 2^200 - 2^100 */
|
|
||||||
mul(t3, t4, t2); /* 2^200 - 2^0 */
|
|
||||||
for (i = 0; i < 25; i++) {
|
|
||||||
sqr(t4, t3);
|
|
||||||
sqr(t3, t4);
|
|
||||||
} /* t3 */ /* 2^250 - 2^50 */
|
|
||||||
mul(t2, t3, t1); /* 2^250 - 2^0 */
|
|
||||||
sqr(t1, t2); /* 2^251 - 2^1 */
|
|
||||||
sqr(t2, t1); /* 2^252 - 2^2 */
|
|
||||||
if (sqrtassist!=0) {
|
|
||||||
mul(y, x, t2); /* 2^252 - 3 */
|
|
||||||
} else {
|
|
||||||
sqr(t1, t2); /* 2^253 - 2^3 */
|
|
||||||
sqr(t2, t1); /* 2^254 - 2^4 */
|
|
||||||
sqr(t1, t2); /* 2^255 - 2^5 */
|
|
||||||
mul(y, t1, t0); /* 2^255 - 21 */
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/* checks if x is "negative", requires reduced input */
|
|
||||||
private static final int is_negative(long10 x) {
|
|
||||||
return (int)(((is_overflow(x) || (x._9 < 0))?1:0) ^ (x._0 & 1));
|
|
||||||
}
|
|
||||||
|
|
||||||
/* a square root */
|
|
||||||
private static final void sqrt(long10 x, long10 u) {
|
|
||||||
long10 v=new long10(), t1=new long10(), t2=new long10();
|
|
||||||
add(t1, u, u); /* t1 = 2u */
|
|
||||||
recip(v, t1, 1); /* v = (2u)^((p-5)/8) */
|
|
||||||
sqr(x, v); /* x = v^2 */
|
|
||||||
mul(t2, t1, x); /* t2 = 2uv^2 */
|
|
||||||
t2._0--; /* t2 = 2uv^2-1 */
|
|
||||||
mul(t1, v, t2); /* t1 = v(2uv^2-1) */
|
|
||||||
mul(x, u, t1); /* x = uv(2uv^2-1) */
|
|
||||||
}
|
|
||||||
|
|
||||||
/********************* Elliptic curve *********************/
|
|
||||||
|
|
||||||
/* y^2 = x^3 + 486662 x^2 + x over GF(2^255-19) */
|
|
||||||
|
|
||||||
/* t1 = ax + az
|
|
||||||
* t2 = ax - az */
|
|
||||||
private static final void mont_prep(long10 t1, long10 t2, long10 ax, long10 az) {
|
|
||||||
add(t1, ax, az);
|
|
||||||
sub(t2, ax, az);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* A = P + Q where
|
|
||||||
* X(A) = ax/az
|
|
||||||
* X(P) = (t1+t2)/(t1-t2)
|
|
||||||
* X(Q) = (t3+t4)/(t3-t4)
|
|
||||||
* X(P-Q) = dx
|
|
||||||
* clobbers t1 and t2, preserves t3 and t4 */
|
|
||||||
private static final void mont_add(long10 t1, long10 t2, long10 t3, long10 t4,long10 ax, long10 az, long10 dx) {
|
|
||||||
mul(ax, t2, t3);
|
|
||||||
mul(az, t1, t4);
|
|
||||||
add(t1, ax, az);
|
|
||||||
sub(t2, ax, az);
|
|
||||||
sqr(ax, t1);
|
|
||||||
sqr(t1, t2);
|
|
||||||
mul(az, t1, dx);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* B = 2 * Q where
|
|
||||||
* X(B) = bx/bz
|
|
||||||
* X(Q) = (t3+t4)/(t3-t4)
|
|
||||||
* clobbers t1 and t2, preserves t3 and t4 */
|
|
||||||
private static final void mont_dbl(long10 t1, long10 t2, long10 t3, long10 t4,long10 bx, long10 bz) {
|
|
||||||
sqr(t1, t3);
|
|
||||||
sqr(t2, t4);
|
|
||||||
mul(bx, t1, t2);
|
|
||||||
sub(t2, t1, t2);
|
|
||||||
mul_small(bz, t2, 121665);
|
|
||||||
add(t1, t1, bz);
|
|
||||||
mul(bz, t1, t2);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Y^2 = X^3 + 486662 X^2 + X
|
|
||||||
* t is a temporary */
|
|
||||||
private static final void x_to_y2(long10 t, long10 y2, long10 x) {
|
|
||||||
sqr(t, x);
|
|
||||||
mul_small(y2, x, 486662);
|
|
||||||
add(t, t, y2);
|
|
||||||
t._0++;
|
|
||||||
mul(y2, t, x);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* P = kG and s = sign(P)/k */
|
|
||||||
private static final void core(byte[] Px, byte[] s, byte[] k, byte[] Gx) {
|
|
||||||
long10
|
|
||||||
dx=new long10(),
|
|
||||||
t1=new long10(),
|
|
||||||
t2=new long10(),
|
|
||||||
t3=new long10(),
|
|
||||||
t4=new long10();
|
|
||||||
long10[]
|
|
||||||
x=new long10[]{new long10(),new long10()},
|
|
||||||
z=new long10[]{new long10(),new long10()};
|
|
||||||
int i, j;
|
|
||||||
|
|
||||||
/* unpack the base */
|
|
||||||
if (Gx!=null)
|
|
||||||
unpack(dx, Gx);
|
|
||||||
else
|
|
||||||
set(dx, 9);
|
|
||||||
|
|
||||||
/* 0G = point-at-infinity */
|
|
||||||
set(x[0], 1);
|
|
||||||
set(z[0], 0);
|
|
||||||
|
|
||||||
/* 1G = G */
|
|
||||||
cpy(x[1], dx);
|
|
||||||
set(z[1], 1);
|
|
||||||
|
|
||||||
for (i = 32; i--!=0; ) {
|
|
||||||
if (i==0) {
|
|
||||||
i=0;
|
|
||||||
}
|
|
||||||
for (j = 8; j--!=0; ) {
|
|
||||||
/* swap arguments depending on bit */
|
|
||||||
int bit1 = (k[i] & 0xFF) >> j & 1;
|
|
||||||
int bit0 = ~(k[i] & 0xFF) >> j & 1;
|
|
||||||
long10 ax = x[bit0];
|
|
||||||
long10 az = z[bit0];
|
|
||||||
long10 bx = x[bit1];
|
|
||||||
long10 bz = z[bit1];
|
|
||||||
|
|
||||||
/* a' = a + b */
|
|
||||||
/* b' = 2 b */
|
|
||||||
mont_prep(t1, t2, ax, az);
|
|
||||||
mont_prep(t3, t4, bx, bz);
|
|
||||||
mont_add(t1, t2, t3, t4, ax, az, dx);
|
|
||||||
mont_dbl(t1, t2, t3, t4, bx, bz);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
recip(t1, z[0], 0);
|
|
||||||
mul(dx, x[0], t1);
|
|
||||||
pack(dx, Px);
|
|
||||||
|
|
||||||
/* calculate s such that s abs(P) = G .. assumes G is std base point */
|
|
||||||
if (s!=null) {
|
|
||||||
x_to_y2(t2, t1, dx); /* t1 = Py^2 */
|
|
||||||
recip(t3, z[1], 0); /* where Q=P+G ... */
|
|
||||||
mul(t2, x[1], t3); /* t2 = Qx */
|
|
||||||
add(t2, t2, dx); /* t2 = Qx + Px */
|
|
||||||
t2._0 += 9 + 486662; /* t2 = Qx + Px + Gx + 486662 */
|
|
||||||
dx._0 -= 9; /* dx = Px - Gx */
|
|
||||||
sqr(t3, dx); /* t3 = (Px - Gx)^2 */
|
|
||||||
mul(dx, t2, t3); /* dx = t2 (Px - Gx)^2 */
|
|
||||||
sub(dx, dx, t1); /* dx = t2 (Px - Gx)^2 - Py^2 */
|
|
||||||
dx._0 -= 39420360; /* dx = t2 (Px - Gx)^2 - Py^2 - Gy^2 */
|
|
||||||
mul(t1, dx, BASE_R2Y); /* t1 = -Py */
|
|
||||||
if (is_negative(t1)!=0) /* sign is 1, so just copy */
|
|
||||||
cpy32(s, k);
|
|
||||||
else /* sign is -1, so negate */
|
|
||||||
mula_small(s, ORDER_TIMES_8, 0, k, 32, -1);
|
|
||||||
|
|
||||||
/* reduce s mod q
|
|
||||||
* (is this needed? do it just in case, it's fast anyway) */
|
|
||||||
//divmod((dstptr) t1, s, 32, order25519, 32);
|
|
||||||
|
|
||||||
/* take reciprocal of s mod q */
|
|
||||||
byte[] temp1=new byte[32];
|
|
||||||
byte[] temp2=new byte[64];
|
|
||||||
byte[] temp3=new byte[64];
|
|
||||||
cpy32(temp1, ORDER);
|
|
||||||
cpy32(s, egcd32(temp2, temp3, s, temp1));
|
|
||||||
if ((s[31] & 0x80)!=0)
|
|
||||||
mula_small(s, s, 0, ORDER, 32, 1);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/* smallest multiple of the order that's >= 2^255 */
|
|
||||||
private static final byte[] ORDER_TIMES_8 = {
|
|
||||||
(byte)104, (byte)159, (byte)174, (byte)231,
|
|
||||||
(byte)210, (byte)24, (byte)147, (byte)192,
|
|
||||||
(byte)178, (byte)230, (byte)188, (byte)23,
|
|
||||||
(byte)245, (byte)206, (byte)247, (byte)166,
|
|
||||||
(byte)0, (byte)0, (byte)0, (byte)0,
|
|
||||||
(byte)0, (byte)0, (byte)0, (byte)0,
|
|
||||||
(byte)0, (byte)0, (byte)0, (byte)0,
|
|
||||||
(byte)0, (byte)0, (byte)0, (byte)128
|
|
||||||
};
|
|
||||||
|
|
||||||
/* constants 2Gy and 1/(2Gy) */
|
|
||||||
private static final long10 BASE_2Y = new long10(
|
|
||||||
39999547, 18689728, 59995525, 1648697, 57546132,
|
|
||||||
24010086, 19059592, 5425144, 63499247, 16420658
|
|
||||||
);
|
|
||||||
private static final long10 BASE_R2Y = new long10(
|
|
||||||
5744, 8160848, 4790893, 13779497, 35730846,
|
|
||||||
12541209, 49101323, 30047407, 40071253, 6226132
|
|
||||||
);
|
|
||||||
}
|
|
||||||
@@ -15,50 +15,89 @@
|
|||||||
*/
|
*/
|
||||||
package net.schmizz.sshj.transport.kex;
|
package net.schmizz.sshj.transport.kex;
|
||||||
|
|
||||||
import com.hierynomus.sshj.common.KeyAlgorithm;
|
|
||||||
import net.schmizz.sshj.common.Factory;
|
import net.schmizz.sshj.common.Factory;
|
||||||
|
import net.schmizz.sshj.common.SecurityUtils;
|
||||||
import net.schmizz.sshj.transport.random.Random;
|
import net.schmizz.sshj.transport.random.Random;
|
||||||
import org.bouncycastle.asn1.x9.X9ECParameters;
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|
||||||
import org.bouncycastle.crypto.ec.CustomNamedCurves;
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|
||||||
import org.bouncycastle.jce.spec.ECParameterSpec;
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|
||||||
|
|
||||||
import java.math.BigInteger;
|
import java.math.BigInteger;
|
||||||
import java.security.GeneralSecurityException;
|
import java.security.GeneralSecurityException;
|
||||||
|
import java.security.KeyFactory;
|
||||||
|
import java.security.KeyPair;
|
||||||
|
import java.security.PublicKey;
|
||||||
import java.security.spec.AlgorithmParameterSpec;
|
import java.security.spec.AlgorithmParameterSpec;
|
||||||
import java.util.Arrays;
|
import java.security.spec.KeySpec;
|
||||||
|
import java.security.spec.X509EncodedKeySpec;
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Key Exchange Method using Curve25519 as defined in RFC 8731
|
||||||
|
*/
|
||||||
public class Curve25519DH extends DHBase {
|
public class Curve25519DH extends DHBase {
|
||||||
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|
||||||
private byte[] secretKey;
|
private static final String ALGORITHM = "X25519";
|
||||||
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|
||||||
|
private static final int ENCODED_ALGORITHM_ID_KEY_LENGTH = 44;
|
||||||
|
|
||||||
|
private static final int ALGORITHM_ID_LENGTH = 12;
|
||||||
|
|
||||||
|
private static final int KEY_LENGTH = 32;
|
||||||
|
|
||||||
|
private final byte[] algorithmId = new byte[ALGORITHM_ID_LENGTH];
|
||||||
|
|
||||||
public Curve25519DH() {
|
public Curve25519DH() {
|
||||||
super(KeyAlgorithm.ECDSA, "ECDH");
|
super(ALGORITHM, ALGORITHM);
|
||||||
}
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|
||||||
|
|
||||||
@Override
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|
||||||
void computeK(byte[] f) throws GeneralSecurityException {
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|
||||||
byte[] k = new byte[32];
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|
||||||
djb.Curve25519.curve(k, secretKey, f);
|
|
||||||
setK(new BigInteger(1, k));
|
|
||||||
}
|
|
||||||
|
|
||||||
@Override
|
|
||||||
public void init(AlgorithmParameterSpec params, Factory<Random> randomFactory) throws GeneralSecurityException {
|
|
||||||
Random random = randomFactory.create();
|
|
||||||
byte[] secretBytes = new byte[32];
|
|
||||||
random.fill(secretBytes);
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|
||||||
byte[] publicBytes = new byte[32];
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|
||||||
djb.Curve25519.keygen(publicBytes, null, secretBytes);
|
|
||||||
this.secretKey = Arrays.copyOf(secretBytes, secretBytes.length);
|
|
||||||
setE(publicBytes);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* TODO want to figure out why BouncyCastle does not work.
|
* Compute Shared Secret Key using Diffie-Hellman Curve25519 known as X25519
|
||||||
* @return The initialized curve25519 parameter spec
|
*
|
||||||
|
* @param peerPublicKey Peer public key bytes
|
||||||
|
* @throws GeneralSecurityException Thrown on key agreement failures
|
||||||
*/
|
*/
|
||||||
public static AlgorithmParameterSpec getCurve25519Params() {
|
@Override
|
||||||
X9ECParameters ecP = CustomNamedCurves.getByName("curve25519");
|
void computeK(final byte[] peerPublicKey) throws GeneralSecurityException {
|
||||||
return new ECParameterSpec(ecP.getCurve(), ecP.getG(), ecP.getN(), ecP.getH(), ecP.getSeed());
|
final KeyFactory keyFactory = SecurityUtils.getKeyFactory(ALGORITHM);
|
||||||
|
final KeySpec peerPublicKeySpec = getPeerPublicKeySpec(peerPublicKey);
|
||||||
|
final PublicKey generatedPeerPublicKey = keyFactory.generatePublic(peerPublicKeySpec);
|
||||||
|
|
||||||
|
agreement.doPhase(generatedPeerPublicKey, true);
|
||||||
|
final byte[] sharedSecretKey = agreement.generateSecret();
|
||||||
|
final BigInteger sharedSecretNumber = new BigInteger(BigInteger.ONE.signum(), sharedSecretKey);
|
||||||
|
setK(sharedSecretNumber);
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Initialize Key Agreement with generated Public and Private Key Pair
|
||||||
|
*
|
||||||
|
* @param params Parameters not used
|
||||||
|
* @param randomFactory Random Factory not used
|
||||||
|
* @throws GeneralSecurityException Thrown on key agreement initialization failures
|
||||||
|
*/
|
||||||
|
@Override
|
||||||
|
public void init(final AlgorithmParameterSpec params, final Factory<Random> randomFactory) throws GeneralSecurityException {
|
||||||
|
final KeyPair keyPair = generator.generateKeyPair();
|
||||||
|
agreement.init(keyPair.getPrivate());
|
||||||
|
setPublicKey(keyPair.getPublic());
|
||||||
|
}
|
||||||
|
|
||||||
|
private void setPublicKey(final PublicKey publicKey) {
|
||||||
|
final byte[] encoded = publicKey.getEncoded();
|
||||||
|
|
||||||
|
// Encoded public key consists of the algorithm identifier and public key
|
||||||
|
if (encoded.length == ENCODED_ALGORITHM_ID_KEY_LENGTH) {
|
||||||
|
final byte[] publicKeyEncoded = new byte[KEY_LENGTH];
|
||||||
|
System.arraycopy(encoded, ALGORITHM_ID_LENGTH, publicKeyEncoded, 0, KEY_LENGTH);
|
||||||
|
setE(publicKeyEncoded);
|
||||||
|
|
||||||
|
// Save Algorithm Identifier byte array
|
||||||
|
System.arraycopy(encoded, 0, algorithmId, 0, ALGORITHM_ID_LENGTH);
|
||||||
|
} else {
|
||||||
|
throw new IllegalArgumentException(String.format("X25519 unsupported public key length [%d]", encoded.length));
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
private KeySpec getPeerPublicKeySpec(final byte[] peerPublicKey) {
|
||||||
|
final byte[] encodedKeySpec = new byte[ENCODED_ALGORITHM_ID_KEY_LENGTH];
|
||||||
|
System.arraycopy(algorithmId, 0, encodedKeySpec, 0, ALGORITHM_ID_LENGTH);
|
||||||
|
System.arraycopy(peerPublicKey, 0, encodedKeySpec, ALGORITHM_ID_LENGTH, KEY_LENGTH);
|
||||||
|
return new X509EncodedKeySpec(encodedKeySpec);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|||||||
@@ -56,6 +56,6 @@ public class Curve25519SHA256 extends AbstractDHG {
|
|||||||
|
|
||||||
@Override
|
@Override
|
||||||
protected void initDH(DHBase dh) throws GeneralSecurityException {
|
protected void initDH(DHBase dh) throws GeneralSecurityException {
|
||||||
dh.init(Curve25519DH.getCurve25519Params(), trans.getConfig().getRandomFactory());
|
dh.init(null, trans.getConfig().getRandomFactory());
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|||||||
@@ -0,0 +1,60 @@
|
|||||||
|
/*
|
||||||
|
* Copyright (C)2009 - SSHJ Contributors
|
||||||
|
*
|
||||||
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
|
* you may not use this file except in compliance with the License.
|
||||||
|
* You may obtain a copy of the License at
|
||||||
|
*
|
||||||
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||||||
|
*
|
||||||
|
* Unless required by applicable law or agreed to in writing, software
|
||||||
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||||
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||||
|
* See the License for the specific language governing permissions and
|
||||||
|
* limitations under the License.
|
||||||
|
*/
|
||||||
|
package net.schmizz.sshj.transport.kex;
|
||||||
|
|
||||||
|
import net.schmizz.sshj.transport.random.JCERandom;
|
||||||
|
import org.junit.Test;
|
||||||
|
|
||||||
|
import java.math.BigInteger;
|
||||||
|
import java.security.GeneralSecurityException;
|
||||||
|
|
||||||
|
import static org.junit.Assert.assertEquals;
|
||||||
|
import static org.junit.Assert.assertNotNull;
|
||||||
|
|
||||||
|
public class Curve25519DHTest {
|
||||||
|
|
||||||
|
private static final int KEY_LENGTH = 32;
|
||||||
|
|
||||||
|
private static final byte[] PEER_PUBLIC_KEY = {
|
||||||
|
1, 2, 3, 4, 5, 6, 7, 8,
|
||||||
|
1, 2, 3, 4, 5, 6, 7, 8,
|
||||||
|
1, 2, 3, 4, 5, 6, 7, 8,
|
||||||
|
1, 2, 3, 4, 5, 6, 7, 8
|
||||||
|
};
|
||||||
|
|
||||||
|
@Test
|
||||||
|
public void testInitPublicKeyLength() throws GeneralSecurityException {
|
||||||
|
final Curve25519DH dh = new Curve25519DH();
|
||||||
|
dh.init(null, new JCERandom.Factory());
|
||||||
|
|
||||||
|
final byte[] publicKeyEncoded = dh.getE();
|
||||||
|
|
||||||
|
assertNotNull(publicKeyEncoded);
|
||||||
|
assertEquals(KEY_LENGTH, publicKeyEncoded.length);
|
||||||
|
}
|
||||||
|
|
||||||
|
@Test
|
||||||
|
public void testInitComputeSharedSecretKey() throws GeneralSecurityException {
|
||||||
|
final Curve25519DH dh = new Curve25519DH();
|
||||||
|
dh.init(null, new JCERandom.Factory());
|
||||||
|
|
||||||
|
dh.computeK(PEER_PUBLIC_KEY);
|
||||||
|
final BigInteger sharedSecretKey = dh.getK();
|
||||||
|
|
||||||
|
assertNotNull(sharedSecretKey);
|
||||||
|
assertEquals(BigInteger.ONE.signum(), sharedSecretKey.signum());
|
||||||
|
}
|
||||||
|
}
|
||||||
Reference in New Issue
Block a user