mirror of
https://git.libssh.org/projects/libssh.git
synced 2025-06-05 01:42:10 +03:00
curve25519: include reference implementation
This commit is contained in:
Aris Adamantiadis
parent
ebf4a03908
commit
c5ef5ed18f
@ -26,15 +26,23 @@
|
||||
|
||||
#ifdef WITH_NACL
|
||||
|
||||
#define HAVE_CURVE25519
|
||||
#include <nacl/crypto_scalarmult_curve25519.h>
|
||||
#define CURVE25519_PUBKEY_SIZE crypto_scalarmult_curve25519_BYTES
|
||||
#define CURVE25519_PRIVKEY_SIZE crypto_scalarmult_curve25519_SCALARBYTES
|
||||
#define crypto_scalarmult_base crypto_scalarmult_curve25519_base
|
||||
#define crypto_scalarmult crypto_scalarmult_curve25519
|
||||
#else
|
||||
|
||||
#define CURVE25519_PUBKEY_SIZE 32
|
||||
#define CURVE25519_PRIVKEY_SIZE 32
|
||||
int crypto_scalarmult_base(unsigned char *q, const unsigned char *n);
|
||||
int crypto_scalarmult(unsigned char *q, const unsigned char *n, const unsigned char *p);
|
||||
#endif /* WITH_NACL */
|
||||
|
||||
#define HAVE_CURVE25519
|
||||
typedef unsigned char ssh_curve25519_pubkey[CURVE25519_PUBKEY_SIZE];
|
||||
typedef unsigned char ssh_curve25519_privkey[CURVE25519_PRIVKEY_SIZE];
|
||||
|
||||
#endif /* WITH_NACL */
|
||||
|
||||
int ssh_client_curve25519_init(ssh_session session);
|
||||
int ssh_client_curve25519_reply(ssh_session session, ssh_buffer packet);
|
||||
|
||||
@ -115,6 +115,7 @@ set(libssh_SRCS
|
||||
client.c
|
||||
config.c
|
||||
connect.c
|
||||
curve25519.c
|
||||
dh.c
|
||||
ecdh.c
|
||||
error.c
|
||||
@ -204,12 +205,12 @@ if (WITH_GSSAPI AND GSSAPI_FOUND)
|
||||
)
|
||||
endif (WITH_GSSAPI AND GSSAPI_FOUND)
|
||||
|
||||
if (WITH_NACL)
|
||||
if (NOT WITH_NACL)
|
||||
set(libssh_SRCS
|
||||
${libssh_SRCS}
|
||||
curve25519.c
|
||||
curve25519_ref.c
|
||||
)
|
||||
endif (WITH_NACL)
|
||||
endif (NOT WITH_NACL)
|
||||
|
||||
include_directories(
|
||||
${LIBSSH_PUBLIC_INCLUDE_DIRS}
|
||||
|
||||
@ -26,7 +26,10 @@
|
||||
#include "libssh/curve25519.h"
|
||||
#ifdef HAVE_CURVE25519
|
||||
|
||||
#ifdef WITH_NACL
|
||||
#include "nacl/crypto_scalarmult_curve25519.h"
|
||||
#endif
|
||||
|
||||
#include "libssh/ssh2.h"
|
||||
#include "libssh/buffer.h"
|
||||
#include "libssh/priv.h"
|
||||
@ -53,7 +56,7 @@ int ssh_client_curve25519_init(ssh_session session){
|
||||
return SSH_ERROR;
|
||||
}
|
||||
|
||||
crypto_scalarmult_curve25519_base(session->next_crypto->curve25519_client_pubkey,
|
||||
crypto_scalarmult_base(session->next_crypto->curve25519_client_pubkey,
|
||||
session->next_crypto->curve25519_privkey);
|
||||
client_pubkey = ssh_string_new(CURVE25519_PUBKEY_SIZE);
|
||||
if (client_pubkey == NULL) {
|
||||
@ -81,10 +84,10 @@ static int ssh_curve25519_build_k(ssh_session session) {
|
||||
}
|
||||
|
||||
if (session->server)
|
||||
crypto_scalarmult_curve25519(k, session->next_crypto->curve25519_privkey,
|
||||
crypto_scalarmult(k, session->next_crypto->curve25519_privkey,
|
||||
session->next_crypto->curve25519_client_pubkey);
|
||||
else
|
||||
crypto_scalarmult_curve25519(k, session->next_crypto->curve25519_privkey,
|
||||
crypto_scalarmult(k, session->next_crypto->curve25519_privkey,
|
||||
session->next_crypto->curve25519_server_pubkey);
|
||||
|
||||
BN_bin2bn(k, CURVE25519_PUBKEY_SIZE, session->next_crypto->k);
|
||||
@ -195,7 +198,7 @@ int ssh_server_curve25519_init(ssh_session session, ssh_buffer packet){
|
||||
return SSH_ERROR;
|
||||
}
|
||||
|
||||
crypto_scalarmult_curve25519_base(session->next_crypto->curve25519_server_pubkey,
|
||||
crypto_scalarmult_base(session->next_crypto->curve25519_server_pubkey,
|
||||
session->next_crypto->curve25519_privkey);
|
||||
|
||||
q_s_string = ssh_string_new(CURVE25519_PUBKEY_SIZE);
|
||||
|
||||
272
src/curve25519_ref.c
Normal file
272
src/curve25519_ref.c
Normal file
@ -0,0 +1,272 @@
|
||||
/*
|
||||
version 20081011
|
||||
Matthew Dempsky
|
||||
Public domain.
|
||||
Derived from public domain code by D. J. Bernstein.
|
||||
*/
|
||||
|
||||
#include "libssh/curve25519.h"
|
||||
static const unsigned char base[32] = {9};
|
||||
|
||||
int crypto_scalarmult_base(unsigned char *q,
|
||||
const unsigned char *n)
|
||||
{
|
||||
return crypto_scalarmult(q,n,base);
|
||||
}
|
||||
|
||||
static void add(unsigned int out[32],const unsigned int a[32],const unsigned int b[32])
|
||||
{
|
||||
unsigned int j;
|
||||
unsigned int u;
|
||||
u = 0;
|
||||
for (j = 0;j < 31;++j) { u += a[j] + b[j]; out[j] = u & 255; u >>= 8; }
|
||||
u += a[31] + b[31]; out[31] = u;
|
||||
}
|
||||
|
||||
static void sub(unsigned int out[32],const unsigned int a[32],const unsigned int b[32])
|
||||
{
|
||||
unsigned int j;
|
||||
unsigned int u;
|
||||
u = 218;
|
||||
for (j = 0;j < 31;++j) {
|
||||
u += a[j] + 65280 - b[j];
|
||||
out[j] = u & 255;
|
||||
u >>= 8;
|
||||
}
|
||||
u += a[31] - b[31];
|
||||
out[31] = u;
|
||||
}
|
||||
|
||||
static void squeeze(unsigned int a[32])
|
||||
{
|
||||
unsigned int j;
|
||||
unsigned int u;
|
||||
u = 0;
|
||||
for (j = 0;j < 31;++j) { u += a[j]; a[j] = u & 255; u >>= 8; }
|
||||
u += a[31]; a[31] = u & 127;
|
||||
u = 19 * (u >> 7);
|
||||
for (j = 0;j < 31;++j) { u += a[j]; a[j] = u & 255; u >>= 8; }
|
||||
u += a[31]; a[31] = u;
|
||||
}
|
||||
|
||||
static const unsigned int minusp[32] = {
|
||||
19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128
|
||||
} ;
|
||||
|
||||
static void freeze(unsigned int a[32])
|
||||
{
|
||||
unsigned int aorig[32];
|
||||
unsigned int j;
|
||||
unsigned int negative;
|
||||
|
||||
for (j = 0;j < 32;++j) aorig[j] = a[j];
|
||||
add(a,a,minusp);
|
||||
negative = -((a[31] >> 7) & 1);
|
||||
for (j = 0;j < 32;++j) a[j] ^= negative & (aorig[j] ^ a[j]);
|
||||
}
|
||||
|
||||
static void mult(unsigned int out[32],const unsigned int a[32],const unsigned int b[32])
|
||||
{
|
||||
unsigned int i;
|
||||
unsigned int j;
|
||||
unsigned int u;
|
||||
|
||||
for (i = 0;i < 32;++i) {
|
||||
u = 0;
|
||||
for (j = 0;j <= i;++j) u += a[j] * b[i - j];
|
||||
for (j = i + 1;j < 32;++j) u += 38 * a[j] * b[i + 32 - j];
|
||||
out[i] = u;
|
||||
}
|
||||
squeeze(out);
|
||||
}
|
||||
|
||||
static void mult121665(unsigned int out[32],const unsigned int a[32])
|
||||
{
|
||||
unsigned int j;
|
||||
unsigned int u;
|
||||
|
||||
u = 0;
|
||||
for (j = 0;j < 31;++j) { u += 121665 * a[j]; out[j] = u & 255; u >>= 8; }
|
||||
u += 121665 * a[31]; out[31] = u & 127;
|
||||
u = 19 * (u >> 7);
|
||||
for (j = 0;j < 31;++j) { u += out[j]; out[j] = u & 255; u >>= 8; }
|
||||
u += out[j]; out[j] = u;
|
||||
}
|
||||
|
||||
static void square(unsigned int out[32],const unsigned int a[32])
|
||||
{
|
||||
unsigned int i;
|
||||
unsigned int j;
|
||||
unsigned int u;
|
||||
|
||||
for (i = 0;i < 32;++i) {
|
||||
u = 0;
|
||||
for (j = 0;j < i - j;++j) u += a[j] * a[i - j];
|
||||
for (j = i + 1;j < i + 32 - j;++j) u += 38 * a[j] * a[i + 32 - j];
|
||||
u *= 2;
|
||||
if ((i & 1) == 0) {
|
||||
u += a[i / 2] * a[i / 2];
|
||||
u += 38 * a[i / 2 + 16] * a[i / 2 + 16];
|
||||
}
|
||||
out[i] = u;
|
||||
}
|
||||
squeeze(out);
|
||||
}
|
||||
|
||||
static void c_select(unsigned int p[64],unsigned int q[64],const unsigned int r[64],const unsigned int s[64],unsigned int b)
|
||||
{
|
||||
unsigned int j;
|
||||
unsigned int t;
|
||||
unsigned int bminus1;
|
||||
|
||||
bminus1 = b - 1;
|
||||
for (j = 0;j < 64;++j) {
|
||||
t = bminus1 & (r[j] ^ s[j]);
|
||||
p[j] = s[j] ^ t;
|
||||
q[j] = r[j] ^ t;
|
||||
}
|
||||
}
|
||||
|
||||
static void mainloop(unsigned int work[64],const unsigned char e[32])
|
||||
{
|
||||
unsigned int xzm1[64];
|
||||
unsigned int xzm[64];
|
||||
unsigned int xzmb[64];
|
||||
unsigned int xzm1b[64];
|
||||
unsigned int xznb[64];
|
||||
unsigned int xzn1b[64];
|
||||
unsigned int a0[64];
|
||||
unsigned int a1[64];
|
||||
unsigned int b0[64];
|
||||
unsigned int b1[64];
|
||||
unsigned int c1[64];
|
||||
unsigned int r[32];
|
||||
unsigned int s[32];
|
||||
unsigned int t[32];
|
||||
unsigned int u[32];
|
||||
unsigned int j;
|
||||
unsigned int b;
|
||||
int pos;
|
||||
|
||||
for (j = 0;j < 32;++j) xzm1[j] = work[j];
|
||||
xzm1[32] = 1;
|
||||
for (j = 33;j < 64;++j) xzm1[j] = 0;
|
||||
|
||||
xzm[0] = 1;
|
||||
for (j = 1;j < 64;++j) xzm[j] = 0;
|
||||
|
||||
for (pos = 254;pos >= 0;--pos) {
|
||||
b = e[pos / 8] >> (pos & 7);
|
||||
b &= 1;
|
||||
c_select(xzmb,xzm1b,xzm,xzm1,b);
|
||||
add(a0,xzmb,xzmb + 32);
|
||||
sub(a0 + 32,xzmb,xzmb + 32);
|
||||
add(a1,xzm1b,xzm1b + 32);
|
||||
sub(a1 + 32,xzm1b,xzm1b + 32);
|
||||
square(b0,a0);
|
||||
square(b0 + 32,a0 + 32);
|
||||
mult(b1,a1,a0 + 32);
|
||||
mult(b1 + 32,a1 + 32,a0);
|
||||
add(c1,b1,b1 + 32);
|
||||
sub(c1 + 32,b1,b1 + 32);
|
||||
square(r,c1 + 32);
|
||||
sub(s,b0,b0 + 32);
|
||||
mult121665(t,s);
|
||||
add(u,t,b0);
|
||||
mult(xznb,b0,b0 + 32);
|
||||
mult(xznb + 32,s,u);
|
||||
square(xzn1b,c1);
|
||||
mult(xzn1b + 32,r,work);
|
||||
c_select(xzm,xzm1,xznb,xzn1b,b);
|
||||
}
|
||||
|
||||
for (j = 0;j < 64;++j) work[j] = xzm[j];
|
||||
}
|
||||
|
||||
static void recip(unsigned int out[32],const unsigned int z[32])
|
||||
{
|
||||
unsigned int z2[32];
|
||||
unsigned int z9[32];
|
||||
unsigned int z11[32];
|
||||
unsigned int z2_5_0[32];
|
||||
unsigned int z2_10_0[32];
|
||||
unsigned int z2_20_0[32];
|
||||
unsigned int z2_50_0[32];
|
||||
unsigned int z2_100_0[32];
|
||||
unsigned int t0[32];
|
||||
unsigned int t1[32];
|
||||
int i;
|
||||
|
||||
/* 2 */ square(z2,z);
|
||||
/* 4 */ square(t1,z2);
|
||||
/* 8 */ square(t0,t1);
|
||||
/* 9 */ mult(z9,t0,z);
|
||||
/* 11 */ mult(z11,z9,z2);
|
||||
/* 22 */ square(t0,z11);
|
||||
/* 2^5 - 2^0 = 31 */ mult(z2_5_0,t0,z9);
|
||||
|
||||
/* 2^6 - 2^1 */ square(t0,z2_5_0);
|
||||
/* 2^7 - 2^2 */ square(t1,t0);
|
||||
/* 2^8 - 2^3 */ square(t0,t1);
|
||||
/* 2^9 - 2^4 */ square(t1,t0);
|
||||
/* 2^10 - 2^5 */ square(t0,t1);
|
||||
/* 2^10 - 2^0 */ mult(z2_10_0,t0,z2_5_0);
|
||||
|
||||
/* 2^11 - 2^1 */ square(t0,z2_10_0);
|
||||
/* 2^12 - 2^2 */ square(t1,t0);
|
||||
/* 2^20 - 2^10 */ for (i = 2;i < 10;i += 2) { square(t0,t1); square(t1,t0); }
|
||||
/* 2^20 - 2^0 */ mult(z2_20_0,t1,z2_10_0);
|
||||
|
||||
/* 2^21 - 2^1 */ square(t0,z2_20_0);
|
||||
/* 2^22 - 2^2 */ square(t1,t0);
|
||||
/* 2^40 - 2^20 */ for (i = 2;i < 20;i += 2) { square(t0,t1); square(t1,t0); }
|
||||
/* 2^40 - 2^0 */ mult(t0,t1,z2_20_0);
|
||||
|
||||
/* 2^41 - 2^1 */ square(t1,t0);
|
||||
/* 2^42 - 2^2 */ square(t0,t1);
|
||||
/* 2^50 - 2^10 */ for (i = 2;i < 10;i += 2) { square(t1,t0); square(t0,t1); }
|
||||
/* 2^50 - 2^0 */ mult(z2_50_0,t0,z2_10_0);
|
||||
|
||||
/* 2^51 - 2^1 */ square(t0,z2_50_0);
|
||||
/* 2^52 - 2^2 */ square(t1,t0);
|
||||
/* 2^100 - 2^50 */ for (i = 2;i < 50;i += 2) { square(t0,t1); square(t1,t0); }
|
||||
/* 2^100 - 2^0 */ mult(z2_100_0,t1,z2_50_0);
|
||||
|
||||
/* 2^101 - 2^1 */ square(t1,z2_100_0);
|
||||
/* 2^102 - 2^2 */ square(t0,t1);
|
||||
/* 2^200 - 2^100 */ for (i = 2;i < 100;i += 2) { square(t1,t0); square(t0,t1); }
|
||||
/* 2^200 - 2^0 */ mult(t1,t0,z2_100_0);
|
||||
|
||||
/* 2^201 - 2^1 */ square(t0,t1);
|
||||
/* 2^202 - 2^2 */ square(t1,t0);
|
||||
/* 2^250 - 2^50 */ for (i = 2;i < 50;i += 2) { square(t0,t1); square(t1,t0); }
|
||||
/* 2^250 - 2^0 */ mult(t0,t1,z2_50_0);
|
||||
|
||||
/* 2^251 - 2^1 */ square(t1,t0);
|
||||
/* 2^252 - 2^2 */ square(t0,t1);
|
||||
/* 2^253 - 2^3 */ square(t1,t0);
|
||||
/* 2^254 - 2^4 */ square(t0,t1);
|
||||
/* 2^255 - 2^5 */ square(t1,t0);
|
||||
/* 2^255 - 21 */ mult(out,t1,z11);
|
||||
}
|
||||
|
||||
int crypto_scalarmult(unsigned char *q,
|
||||
const unsigned char *n,
|
||||
const unsigned char *p)
|
||||
{
|
||||
unsigned int work[96];
|
||||
unsigned char e[32];
|
||||
unsigned int i;
|
||||
for (i = 0;i < 32;++i) e[i] = n[i];
|
||||
e[0] &= 248;
|
||||
e[31] &= 127;
|
||||
e[31] |= 64;
|
||||
for (i = 0;i < 32;++i) work[i] = p[i];
|
||||
mainloop(work,e);
|
||||
recip(work + 32,work + 32);
|
||||
mult(work + 64,work,work + 32);
|
||||
freeze(work + 64);
|
||||
for (i = 0;i < 32;++i) q[i] = work[64 + i];
|
||||
return 0;
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user