ECDSA

Ivan83
Joined:: 2013-11-27
Posts:: 5
Location:: Russia, Moscow

ECDSA – I can help with code

2013-11-27 12:54

Hi!

I wrote the code to work with ECDSA.
BSD License.
ECDSA can help with your project.

Ivan83
Joined:: 2013-11-27
Posts:: 5
Location:: Russia, Moscow

2013-11-28 08:52

#include "ec.h"
 
...
 
size_t rsize;
uint8_t rnd[70], priv_key[70], pub_key_x[70], pub_key_y[70], sign_r[70], sign_s[70];
ec_curve_t curve;
/*  SHA-1("abc") = "a9993e364706816aba3e25717850c26c9cd0d89d" */ uint8_t hash_abc[20] = {0xa9, 0x99, 0x3e, 0x36, 0x47, 0x06, 0x81, 0x6a, 0xba, 0x3e, 0x25, 0x71, 0x78, 0x50, 0xc2, 0x6c, 0x9c, 0xd0, 0xd8, 0x9d};
 
/* Get curve params by name. */
if (0 != ec_curve_from_str(ec_curve_str_get_by_name((uint8_t*)"secp192r1", 9), &curve))
   return (-1);
 
/* Generating keys. */
memset(rnd, 173, sizeof(rnd));/* XXX rand!!! */
if (0 != ec_key_gen(rnd, sizeof(rnd), &curve, priv_key, pub_key_x, pub_key_y, &rsize))
   return (-1); /* Error! */
 
/* Sign */
memset(rnd, 73, sizeof(rnd));/* XXX rand!!! */
if (0 != ec_sign((uint8_t*)hash_abc, 20, priv_key, rsize, rnd, sizeof(rnd), &curve, sign_r, sign_s, &rsize))
   return (-1); /* Error! */
 
/* Verify */
if (0 != ec_verify(&curve, pub_key_x, pub_key_y, rsize, (uint8_t*)hash_abc, 20, sign_r, sign_s, rsize))
   return (-1); /* Error! */

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martin◆ Site Admin
Joined:: 2002-12-10
Posts:: 43,035
Location:: Prague, Czechia

Re: ECDSA - i can help with code

2013-11-28

Thanks for sharing your code. Could you contact PuTTY team and offer them help integrating this to PuTTY codebase?
https://www.chiark.greenend.org.uk/~sgtatham/putty/feedback.html

We will takeover the implementation then. Thanks.

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Ivan83

2013-11-28 16:35

Already written them: [email protected]
They expect to see a patch for the PuTTY, but I do not want to learn SSH protocol.

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martin◆ Site Admin

2013-12-02

Ok, I see. Thanks for trying.

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Gatak Guest

2014-01-07 14:03

I read there is a growing concern about elliptic-curve cryptography and that the curves in the current standards have been "influenced" by NSA – to what end we can only guess.

Unless you are thinking of Curve25519, it may be wise to be conservative and stick to RSA with high bit encryption.
ref: https://git.libssh.org/projects/libssh.git/tree/doc/[email protected]

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Ivan83
Joined:: 2013-11-27
Posts:: 5
Location:: Russia, Moscow

2014-01-07 18:57

There are many different parameters of elliptic curves.
Some appeared in the work in 1998.
There are parameters of elliptic curves generated not in the United States .
There are Russian version where in the formulas are slightly different coefficients and parameters of their curves.
All formulas and algorithms have long existed and analyzing it is described how to generate the most options for elliptic curves.
However, 25519 appeared not long ago, the formula calculations there several others, and I have not seen this work on cryptanalysis "works of art". And almost all implementations in assembler.
So if anyone does not believe it is 25519. This is my personal opinion.

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Guest

2014-01-07 19:30

Sure, but are these (Russian and other) alternatives available in OpenSSH, OpenSSL or GnuTLS?

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Ivan83

2014-01-07 20:16

Brainpool, GOST in OpenSSL.

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Baebeca Guest

Re: ECDSA - i can help with code

2015-03-13 10:34

@martin
PuTTY has released full SSH2-ECDSA support in there current nightly snapshot. (https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html)

I can't find SSH2-ECDSA support in your current version or in your project roadmap.
Is there any status to SSH2-ECDSA support?

Thanks so far!

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martin◆ Site Admin

Re: ECDSA - i can help with code

2015-03-16

@Baebeca: I'll look into it.
But note they deliberately did not include ECDSA into recent PuTTY 0.64 release. I'm sure there's a reason for that.

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Baebeca