nhyatt/putty-source
1
0
Fork 0
mirror of https://git.tartarus.org/simon/putty.git synced 2025-04-23 22:15:02 -05:00
Code Issues Projects Releases Wiki Activity

Log which elliptic curve we're using for ECDH kex.

Browse Source 
It seems like quite an important thing to mention in the event log!
Suppose there's a bug affecting only one curve, for example? Fixed-
group Diffie-Hellman has always logged the group, but the ECDH log
message just told you the hash and not also the curve.

To implement this, I've added a 'textname' field to all elliptic
curves, whether they're used for kex or signing or both, suitable for
use in this log message and any others we might find a need for in
future.
This commit is contained in:
Simon Tatham 2015-05-19 08:42:23 +01:00
parent 35fde00fd1
commit a209b9044e
3 changed files with 23 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
ssh.c
View File

@ -6770,7 +6770,8 @@ static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
}
} else if (ssh->kex->main_type == KEXTYPE_ECDH) {
logeventf(ssh, "Doing ECDH key exchange with hash %s",
logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
ssh_ecdhkex_curve_textname(ssh->kex),
ssh->kex->hash->text_name);
ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;

10
ssh.h
View File

@ -134,7 +134,14 @@ struct ec_ecurve
struct ec_curve {
enum { EC_WEIERSTRASS, EC_MONTGOMERY, EC_EDWARDS } type;
const char *name;
/* 'name' is the identifier of the curve when it has to appear in
* wire protocol encodings, as it does in e.g. the public key and
* signature formats for NIST curves. Curves which do not format
* their keys or signatures in this way just have name==NULL.
*
* 'textname' is non-NULL for all curves, and is a human-readable
* identification suitable for putting in log messages. */
const char *name, *textname;
unsigned int fieldBits;
Bignum p;
union {
@ -210,6 +217,7 @@ void ssh_rsakex_encrypt(const struct ssh_hash *h, unsigned char *in, int inlen,
* SSH2 ECDH key exchange functions
*/
struct ssh_kex;
const char *ssh_ecdhkex_curve_textname(const struct ssh_kex *kex);
void *ssh_ecdhkex_newkey(const struct ssh_kex *kex);
void ssh_ecdhkex_freekey(void *key);
char *ssh_ecdhkex_getpublic(void *key, int *len);

15
sshecc.c
View File

@ -157,7 +157,7 @@ static struct ec_curve *ec_p256(void)
};
initialise_wcurve(&curve, 256, p, a, b, n, Gx, Gy);
curve.name = "nistp256";
curve.textname = curve.name = "nistp256";
/* Now initialised, no need to do it again */
initialised = 1;
@ -223,7 +223,7 @@ static struct ec_curve *ec_p384(void)
};
initialise_wcurve(&curve, 384, p, a, b, n, Gx, Gy);
curve.name = "nistp384";
curve.textname = curve.name = "nistp384";
/* Now initialised, no need to do it again */
initialised = 1;
@ -307,7 +307,7 @@ static struct ec_curve *ec_p521(void)
};
initialise_wcurve(&curve, 521, p, a, b, n, Gx, Gy);
curve.name = "nistp521";
curve.textname = curve.name = "nistp521";
/* Now initialised, no need to do it again */
initialised = 1;
@ -352,6 +352,7 @@ static struct ec_curve *ec_curve25519(void)
/* This curve doesn't need a name, because it's never used in
* any format that embeds the curve name */
curve.name = NULL;
curve.textname = "Curve25519";
/* Now initialised, no need to do it again */
initialised = 1;
@ -403,6 +404,7 @@ static struct ec_curve *ec_ed25519(void)
curve.name = NULL;
initialise_ecurve(&curve, 256, q, l, d, Bx, By);
curve.textname = "Ed25519";
/* Now initialised, no need to do it again */
initialised = 1;
@ -2704,6 +2706,13 @@ static Bignum ecdh_calculate(const Bignum private,
return ret;
}
const char *ssh_ecdhkex_curve_textname(const struct ssh_kex *kex)
{
const struct eckex_extra *extra = (const struct eckex_extra *)kex->extra;
struct ec_curve *curve = extra->curve();
return curve->textname;
}
void *ssh_ecdhkex_newkey(const struct ssh_kex *kex)
{
const struct eckex_extra *extra = (const struct eckex_extra *)kex->extra;