ports/libssh
ports/libssh
1
1
Форкнуть 0
Код Релизы 1 Активность
libssh/src/keys.c

1502 строки
37 KiB
C
Исходник Ответственный История

/*
* keys.c - decoding a public key or signature and verifying them
*
* This file is part of the SSH Library
*
* Copyright (c) 2003-2005 by Aris Adamantiadis
*
* The SSH Library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The SSH Library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the SSH Library; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_LIBCRYPTO
#include <openssl/dsa.h>
#include <openssl/rsa.h>
#endif
#include "libssh/priv.h"
#include "libssh/ssh2.h"
#include "libssh/server.h"
#include "libssh/buffer.h"
#include "libssh/agent.h"
#include "libssh/session.h"
#include "libssh/keys.h"
#include "libssh/dh.h"
#include "libssh/messages.h"
#include "libssh/string.h"
/**
* @addtogroup libssh_auth
*
* @{
*/
/* Public key decoding functions */
const char *ssh_type_to_char(int type) {
switch (type) {
case SSH_KEYTYPE_DSS:
return "ssh-dss";
case SSH_KEYTYPE_RSA:
return "ssh-rsa";
case SSH_KEYTYPE_RSA1:
return "ssh-rsa1";
default:
return NULL;
}
}
int ssh_type_from_name(const char *name) {
if (strcmp(name, "rsa1") == 0) {
return SSH_KEYTYPE_RSA1;
} else if (strcmp(name, "rsa") == 0) {
return SSH_KEYTYPE_RSA;
} else if (strcmp(name, "dsa") == 0) {
return SSH_KEYTYPE_DSS;
} else if (strcmp(name, "ssh-rsa1") == 0) {
return SSH_KEYTYPE_RSA1;
} else if (strcmp(name, "ssh-rsa") == 0) {
return SSH_KEYTYPE_RSA;
} else if (strcmp(name, "ssh-dss") == 0) {
return SSH_KEYTYPE_DSS;
}
return -1;
}
ssh_public_key publickey_make_dss(ssh_session session, ssh_buffer buffer) {
ssh_string p = NULL;
ssh_string q = NULL;
ssh_string g = NULL;
ssh_string pubkey = NULL;
ssh_public_key key = NULL;
key = malloc(sizeof(struct ssh_public_key_struct));
if (key == NULL) {
ssh_buffer_free(buffer);
return NULL;
}
key->type = SSH_KEYTYPE_DSS;
key->type_c = ssh_type_to_char(key->type);
p = buffer_get_ssh_string(buffer);
q = buffer_get_ssh_string(buffer);
g = buffer_get_ssh_string(buffer);
pubkey = buffer_get_ssh_string(buffer);
ssh_buffer_free(buffer); /* we don't need it anymore */
if (p == NULL || q == NULL || g == NULL || pubkey == NULL) {
ssh_set_error(session, SSH_FATAL, "Invalid DSA public key");
goto error;
}
#ifdef HAVE_LIBGCRYPT
gcry_sexp_build(&key->dsa_pub, NULL,
"(public-key(dsa(p %b)(q %b)(g %b)(y %b)))",
ssh_string_len(p), ssh_string_data(p),
ssh_string_len(q), ssh_string_data(q),
ssh_string_len(g), ssh_string_data(g),
ssh_string_len(pubkey), ssh_string_data(pubkey));
if (key->dsa_pub == NULL) {
goto error;
}
#elif defined HAVE_LIBCRYPTO
key->dsa_pub = DSA_new();
if (key->dsa_pub == NULL) {
goto error;
}
key->dsa_pub->p = make_string_bn(p);
key->dsa_pub->q = make_string_bn(q);
key->dsa_pub->g = make_string_bn(g);
key->dsa_pub->pub_key = make_string_bn(pubkey);
if (key->dsa_pub->p == NULL ||
key->dsa_pub->q == NULL ||
key->dsa_pub->g == NULL ||
key->dsa_pub->pub_key == NULL) {
goto error;
}
#endif /* HAVE_LIBCRYPTO */
#ifdef DEBUG_CRYPTO
ssh_print_hexa("p", ssh_string_data(p), ssh_string_len(p));
ssh_print_hexa("q", ssh_string_data(q), ssh_string_len(q));
ssh_print_hexa("g", ssh_string_data(g), ssh_string_len(g));
#endif
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(pubkey);
ssh_string_free(pubkey);
return key;
error:
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(pubkey);
ssh_string_free(pubkey);
publickey_free(key);
return NULL;
}
ssh_public_key publickey_make_rsa(ssh_session session, ssh_buffer buffer,
int type) {
ssh_string e = NULL;
ssh_string n = NULL;
ssh_public_key key = NULL;
key = malloc(sizeof(struct ssh_public_key_struct));
if (key == NULL) {
ssh_buffer_free(buffer);
return NULL;
}
key->type = type;
key->type_c = ssh_type_to_char(key->type);
e = buffer_get_ssh_string(buffer);
n = buffer_get_ssh_string(buffer);
ssh_buffer_free(buffer); /* we don't need it anymore */
if(e == NULL || n == NULL) {
ssh_set_error(session, SSH_FATAL, "Invalid RSA public key");
goto error;
}
#ifdef HAVE_LIBGCRYPT
gcry_sexp_build(&key->rsa_pub, NULL,
"(public-key(rsa(n %b)(e %b)))",
ssh_string_len(n), ssh_string_data(n),
ssh_string_len(e),ssh_string_data(e));
if (key->rsa_pub == NULL) {
goto error;
}
#elif HAVE_LIBCRYPTO
key->rsa_pub = RSA_new();
if (key->rsa_pub == NULL) {
goto error;
}
key->rsa_pub->e = make_string_bn(e);
key->rsa_pub->n = make_string_bn(n);
if (key->rsa_pub->e == NULL ||
key->rsa_pub->n == NULL) {
goto error;
}
#endif
#ifdef DEBUG_CRYPTO
ssh_print_hexa("e", ssh_string_data(e), ssh_string_len(e));
ssh_print_hexa("n", ssh_string_data(n), ssh_string_len(n));
#endif
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
return key;
error:
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
publickey_free(key);
return NULL;
}
void publickey_free(ssh_public_key key) {
if (key == NULL) {
return;
}
switch(key->type) {
case SSH_KEYTYPE_DSS:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(key->dsa_pub);
#elif HAVE_LIBCRYPTO
DSA_free(key->dsa_pub);
#endif
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(key->rsa_pub);
#elif defined HAVE_LIBCRYPTO
RSA_free(key->rsa_pub);
#endif
break;
default:
break;
}
SAFE_FREE(key);
}
ssh_public_key publickey_from_string(ssh_session session, ssh_string pubkey_s) {
ssh_buffer tmpbuf = NULL;
ssh_string type_s = NULL;
char *type_c = NULL;
int type;
tmpbuf = ssh_buffer_new();
if (tmpbuf == NULL) {
return NULL;
}
if (buffer_add_data(tmpbuf, ssh_string_data(pubkey_s), ssh_string_len(pubkey_s)) < 0) {
goto error;
}
type_s = buffer_get_ssh_string(tmpbuf);
if (type_s == NULL) {
ssh_set_error(session,SSH_FATAL,"Invalid public key format");
goto error;
}
type_c = ssh_string_to_char(type_s);
ssh_string_free(type_s);
if (type_c == NULL) {
goto error;
}
type = ssh_type_from_name(type_c);
SAFE_FREE(type_c);
switch (type) {
case SSH_KEYTYPE_DSS:
return publickey_make_dss(session, tmpbuf);
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
return publickey_make_rsa(session, tmpbuf, type);
}
ssh_set_error(session, SSH_FATAL, "Unknown public key protocol %s",
ssh_type_to_char(type));
error:
ssh_buffer_free(tmpbuf);
return NULL;
}
/**
* @brief Make a public_key object out of a private_key object.
*
* @param[in] prv The private key to generate the public key.
*
* @returns The generated public key, NULL on error.
*
* @see publickey_to_string()
*/
ssh_public_key publickey_from_privatekey(ssh_private_key prv) {
ssh_public_key key = NULL;
#ifdef HAVE_LIBGCRYPT
gcry_sexp_t sexp;
const char *tmp = NULL;
size_t size;
ssh_string p = NULL;
ssh_string q = NULL;
ssh_string g = NULL;
ssh_string y = NULL;
ssh_string e = NULL;
ssh_string n = NULL;
#endif /* HAVE_LIBGCRYPT */
key = malloc(sizeof(struct ssh_public_key_struct));
if (key == NULL) {
return NULL;
}
ZERO_STRUCTP(key);
key->type = prv->type;
switch(key->type) {
case SSH_KEYTYPE_DSS:
#ifdef HAVE_LIBGCRYPT
sexp = gcry_sexp_find_token(prv->dsa_priv, "p", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
p = ssh_string_new(size);
if (p == NULL) {
goto error;
}
ssh_string_fill(p,(char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(prv->dsa_priv,"q",0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp,1,&size);
q = ssh_string_new(size);
if (q == NULL) {
goto error;
}
ssh_string_fill(q,(char *) tmp,size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(prv->dsa_priv, "g", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp,1,&size);
g = ssh_string_new(size);
if (g == NULL) {
goto error;
}
ssh_string_fill(g,(char *) tmp,size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(prv->dsa_priv,"y",0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp,1,&size);
y = ssh_string_new(size);
if (y == NULL) {
goto error;
}
ssh_string_fill(y,(char *) tmp,size);
gcry_sexp_release(sexp);
gcry_sexp_build(&key->dsa_pub, NULL,
"(public-key(dsa(p %b)(q %b)(g %b)(y %b)))",
ssh_string_len(p), ssh_string_data(p),
ssh_string_len(q), ssh_string_data(q),
ssh_string_len(g), ssh_string_data(g),
ssh_string_len(y), ssh_string_data(y));
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(y);
ssh_string_free(y);
#elif defined HAVE_LIBCRYPTO
key->dsa_pub = DSA_new();
if (key->dsa_pub == NULL) {
goto error;
}
key->dsa_pub->p = BN_dup(prv->dsa_priv->p);
key->dsa_pub->q = BN_dup(prv->dsa_priv->q);
key->dsa_pub->g = BN_dup(prv->dsa_priv->g);
key->dsa_pub->pub_key = BN_dup(prv->dsa_priv->pub_key);
if (key->dsa_pub->p == NULL ||
key->dsa_pub->q == NULL ||
key->dsa_pub->g == NULL ||
key->dsa_pub->pub_key == NULL) {
goto error;
}
#endif /* HAVE_LIBCRYPTO */
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
#ifdef HAVE_LIBGCRYPT
sexp = gcry_sexp_find_token(prv->rsa_priv, "n", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
n = ssh_string_new(size);
if (n == NULL) {
goto error;
}
ssh_string_fill(n, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(prv->rsa_priv, "e", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
e = ssh_string_new(size);
if (e == NULL) {
goto error;
}
ssh_string_fill(e, (char *) tmp, size);
gcry_sexp_release(sexp);
gcry_sexp_build(&key->rsa_pub, NULL,
"(public-key(rsa(n %b)(e %b)))",
ssh_string_len(n), ssh_string_data(n),
ssh_string_len(e), ssh_string_data(e));
if (key->rsa_pub == NULL) {
goto error;
}
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
#elif defined HAVE_LIBCRYPTO
key->rsa_pub = RSA_new();
if (key->rsa_pub == NULL) {
goto error;
}
key->rsa_pub->e = BN_dup(prv->rsa_priv->e);
key->rsa_pub->n = BN_dup(prv->rsa_priv->n);
if (key->rsa_pub->e == NULL ||
key->rsa_pub->n == NULL) {
goto error;
}
#endif
break;
default:
publickey_free(key);
return NULL;
}
key->type_c = ssh_type_to_char(prv->type);
return key;
error:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(sexp);
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(y);
ssh_string_free(y);
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
#endif
publickey_free(key);
return NULL;
}
#ifdef HAVE_LIBGCRYPT
static int dsa_public_to_string(gcry_sexp_t key, ssh_buffer buffer) {
#elif defined HAVE_LIBCRYPTO
static int dsa_public_to_string(DSA *key, ssh_buffer buffer) {
#endif
ssh_string p = NULL;
ssh_string q = NULL;
ssh_string g = NULL;
ssh_string n = NULL;
int rc = -1;
#ifdef HAVE_LIBGCRYPT
const char *tmp = NULL;
size_t size;
gcry_sexp_t sexp;
sexp = gcry_sexp_find_token(key, "p", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
p = ssh_string_new(size);
if (p == NULL) {
goto error;
}
ssh_string_fill(p, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key, "q", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
q = ssh_string_new(size);
if (q == NULL) {
goto error;
}
ssh_string_fill(q, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key, "g", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
g = ssh_string_new(size);
if (g == NULL) {
goto error;
}
ssh_string_fill(g, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key, "y", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
n = ssh_string_new(size);
if (n == NULL) {
goto error;
}
ssh_string_fill(n, (char *) tmp, size);
#elif defined HAVE_LIBCRYPTO
p = make_bignum_string(key->p);
q = make_bignum_string(key->q);
g = make_bignum_string(key->g);
n = make_bignum_string(key->pub_key);
if (p == NULL || q == NULL || g == NULL || n == NULL) {
goto error;
}
#endif /* HAVE_LIBCRYPTO */
if (buffer_add_ssh_string(buffer, p) < 0) {
goto error;
}
if (buffer_add_ssh_string(buffer, q) < 0) {
goto error;
}
if (buffer_add_ssh_string(buffer, g) < 0) {
goto error;
}
if (buffer_add_ssh_string(buffer, n) < 0) {
goto error;
}
rc = 0;
error:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(sexp);
#endif
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(n);
ssh_string_free(n);
return rc;
}
#ifdef HAVE_LIBGCRYPT
static int rsa_public_to_string(gcry_sexp_t key, ssh_buffer buffer) {
#elif defined HAVE_LIBCRYPTO
static int rsa_public_to_string(RSA *key, ssh_buffer buffer) {
#endif
ssh_string e = NULL;
ssh_string n = NULL;
int rc = -1;
#ifdef HAVE_LIBGCRYPT
const char *tmp;
size_t size;
gcry_sexp_t sexp;
sexp = gcry_sexp_find_token(key, "n", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
n = ssh_string_new(size);
if (n == NULL) {
goto error;
}
ssh_string_fill(n, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key, "e", 0);
if (sexp == NULL) {
goto error;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
e = ssh_string_new(size);
if (e == NULL) {
goto error;
}
ssh_string_fill(e, (char *) tmp, size);
#elif defined HAVE_LIBCRYPTO
e = make_bignum_string(key->e);
n = make_bignum_string(key->n);
if (e == NULL || n == NULL) {
goto error;
}
#endif
if (buffer_add_ssh_string(buffer, e) < 0) {
goto error;
}
if (buffer_add_ssh_string(buffer, n) < 0) {
goto error;
}
rc = 0;
error:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(sexp);
#endif
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
return rc;
}
/**
* @brief Convert a public_key object into a a SSH string.
*
* @param[in] key The public key to convert.
*
* @returns An allocated SSH String containing the public key, NULL
* on error.
*
* @see string_free()
*/
ssh_string publickey_to_string(ssh_public_key key) {
ssh_string type = NULL;
ssh_string ret = NULL;
ssh_buffer buf = NULL;
buf = ssh_buffer_new();
if (buf == NULL) {
return NULL;
}
type = ssh_string_from_char(key->type_c);
if (type == NULL) {
goto error;
}
if (buffer_add_ssh_string(buf, type) < 0) {
goto error;
}
switch (key->type) {
case SSH_KEYTYPE_DSS:
if (dsa_public_to_string(key->dsa_pub, buf) < 0) {
goto error;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
if (rsa_public_to_string(key->rsa_pub, buf) < 0) {
goto error;
}
break;
}
ret = ssh_string_new(buffer_get_rest_len(buf));
if (ret == NULL) {
goto error;
}
ssh_string_fill(ret, buffer_get_rest(buf), buffer_get_rest_len(buf));
error:
ssh_buffer_free(buf);
if(type != NULL)
ssh_string_free(type);
return ret;
}
/* Signature decoding functions */
static ssh_string signature_to_string(SIGNATURE *sign) {
unsigned char buffer[40] = {0};
ssh_buffer tmpbuf = NULL;
ssh_string str = NULL;
ssh_string tmp = NULL;
ssh_string rs = NULL;
int rc = -1;
#ifdef HAVE_LIBGCRYPT
const char *r = NULL;
const char *s = NULL;
gcry_sexp_t sexp;
size_t size = 0;
#elif defined HAVE_LIBCRYPTO
ssh_string r = NULL;
ssh_string s = NULL;
#endif
tmpbuf = ssh_buffer_new();
if (tmpbuf == NULL) {
return NULL;
}
tmp = ssh_string_from_char(ssh_type_to_char(sign->type));
if (tmp == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
if (buffer_add_ssh_string(tmpbuf, tmp) < 0) {
ssh_buffer_free(tmpbuf);
ssh_string_free(tmp);
return NULL;
}
ssh_string_free(tmp);
switch(sign->type) {
case SSH_KEYTYPE_DSS:
#ifdef HAVE_LIBGCRYPT
sexp = gcry_sexp_find_token(sign->dsa_sign, "r", 0);
if (sexp == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
r = gcry_sexp_nth_data(sexp, 1, &size);
if (*r == 0) { /* libgcrypt put 0 when first bit is set */
size--;
r++;
}
memcpy(buffer, r + size - 20, 20);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(sign->dsa_sign, "s", 0);
if (sexp == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
s = gcry_sexp_nth_data(sexp,1,&size);
if (*s == 0) {
size--;
s++;
}
memcpy(buffer+ 20, s + size - 20, 20);
gcry_sexp_release(sexp);
#elif defined HAVE_LIBCRYPTO
r = make_bignum_string(sign->dsa_sign->r);
if (r == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
s = make_bignum_string(sign->dsa_sign->s);
if (s == NULL) {
ssh_buffer_free(tmpbuf);
ssh_string_free(r);
return NULL;
}
memcpy(buffer, (char *)ssh_string_data(r) + ssh_string_len(r) - 20, 20);
memcpy(buffer + 20, (char *)ssh_string_data(s) + ssh_string_len(s) - 20, 20);
ssh_string_free(r);
ssh_string_free(s);
#endif /* HAVE_LIBCRYPTO */
rs = ssh_string_new(40);
if (rs == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
ssh_string_fill(rs, buffer, 40);
rc = buffer_add_ssh_string(tmpbuf, rs);
ssh_string_free(rs);
if (rc < 0) {
ssh_buffer_free(tmpbuf);
return NULL;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
#ifdef HAVE_LIBGCRYPT
sexp = gcry_sexp_find_token(sign->rsa_sign, "s", 0);
if (sexp == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
s = gcry_sexp_nth_data(sexp,1,&size);
if (*s == 0) {
size--;
s++;
}
rs = ssh_string_new(size);
if (rs == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
ssh_string_fill(rs, (char *) s, size);
rc = buffer_add_ssh_string(tmpbuf, rs);
gcry_sexp_release(sexp);
ssh_string_free(rs);
if (rc < 0) {
ssh_buffer_free(tmpbuf);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
if (buffer_add_ssh_string(tmpbuf,sign->rsa_sign) < 0) {
ssh_buffer_free(tmpbuf);
return NULL;
}
#endif
break;
}
str = ssh_string_new(buffer_get_rest_len(tmpbuf));
if (str == NULL) {
ssh_buffer_free(tmpbuf);
return NULL;
}
ssh_string_fill(str, buffer_get_rest(tmpbuf), buffer_get_rest_len(tmpbuf));
ssh_buffer_free(tmpbuf);
return str;
}
/* TODO : split this function in two so it becomes smaller */
SIGNATURE *signature_from_string(ssh_session session, ssh_string signature,
ssh_public_key pubkey, int needed_type) {
SIGNATURE *sign = NULL;
ssh_buffer tmpbuf = NULL;
ssh_string rs = NULL;
ssh_string type_s = NULL;
ssh_string e = NULL;
char *type_c = NULL;
int type;
int len;
int rsalen;
#ifdef HAVE_LIBGCRYPT
gcry_sexp_t sig;
#elif defined HAVE_LIBCRYPTO
DSA_SIG *sig = NULL;
ssh_string r = NULL;
ssh_string s = NULL;
#endif
sign = malloc(sizeof(SIGNATURE));
if (sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
return NULL;
}
tmpbuf = ssh_buffer_new();
if (tmpbuf == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
signature_free(sign);
return NULL;
}
if (buffer_add_data(tmpbuf, ssh_string_data(signature), ssh_string_len(signature)) < 0) {
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
type_s = buffer_get_ssh_string(tmpbuf);
if (type_s == NULL) {
ssh_set_error(session, SSH_FATAL, "Invalid signature packet");
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
type_c = ssh_string_to_char(type_s);
ssh_string_free(type_s);
if (type_c == NULL) {
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
type = ssh_type_from_name(type_c);
SAFE_FREE(type_c);
if (needed_type != type) {
ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s",
ssh_type_to_char(type));
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
switch(needed_type) {
case SSH_KEYTYPE_DSS:
rs = buffer_get_ssh_string(tmpbuf);
ssh_buffer_free(tmpbuf);
/* 40 is the dual signature blob len. */
if (rs == NULL || ssh_string_len(rs) != 40) {
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
/* we make use of strings (because we have all-made functions to convert
* them to bignums (ou pas ;) */
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&sig, NULL, "(sig-val(dsa(r %b)(s %b)))",
20 ,ssh_string_data(rs), 20,(unsigned char *)ssh_string_data(rs) + 20)) {
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
r = ssh_string_new(20);
s = ssh_string_new(20);
if (r == NULL || s == NULL) {
ssh_string_free(r);
ssh_string_free(s);
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
ssh_string_fill(r, ssh_string_data(rs), 20);
ssh_string_fill(s, (char *)ssh_string_data(rs) + 20, 20);
sig = DSA_SIG_new();
if (sig == NULL) {
ssh_string_free(r);
ssh_string_free(s);
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
sig->r = make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
sig->s = make_string_bn(s);
ssh_string_free(r);
ssh_string_free(s);
if (sig->r == NULL || sig->s == NULL) {
ssh_string_free(rs);
DSA_SIG_free(sig);
signature_free(sign);
return NULL;
}
#endif
#ifdef DEBUG_CRYPTO
ssh_print_hexa("r", ssh_string_data(rs), 20);
ssh_print_hexa("s", (const unsigned char *)ssh_string_data(rs) + 20, 20);
#endif
ssh_string_free(rs);
sign->type = SSH_KEYTYPE_DSS;
sign->dsa_sign = sig;
return sign;
case SSH_KEYTYPE_RSA:
e = buffer_get_ssh_string(tmpbuf);
ssh_buffer_free(tmpbuf);
if (e == NULL) {
signature_free(sign);
return NULL;
}
len = ssh_string_len(e);
#ifdef HAVE_LIBGCRYPT
rsalen = (gcry_pk_get_nbits(pubkey->rsa_pub) + 7) / 8;
#elif defined HAVE_LIBCRYPTO
rsalen = RSA_size(pubkey->rsa_pub);
#endif
if (len > rsalen) {
ssh_string_free(e);
signature_free(sign);
ssh_set_error(session, SSH_FATAL, "Signature too big! %d instead of %d",
len, rsalen);
return NULL;
}
if (len < rsalen) {
ssh_log(session, SSH_LOG_RARE, "RSA signature len %d < %d",
len, rsalen);
}
sign->type = SSH_KEYTYPE_RSA;
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&sig, NULL, "(sig-val(rsa(s %b)))",
ssh_string_len(e), ssh_string_data(e))) {
signature_free(sign);
ssh_string_free(e);
return NULL;
}
sign->rsa_sign = sig;
#elif defined HAVE_LIBCRYPTO
sign->rsa_sign = e;
#endif
#ifdef DEBUG_CRYPTO
ssh_log(session, SSH_LOG_FUNCTIONS, "len e: %d", len);
ssh_print_hexa("RSA signature", ssh_string_data(e), len);
#endif
#ifdef HAVE_LIBGCRYPT
ssh_string_free(e);
#endif
return sign;
default:
return NULL;
}
return NULL;
}
void signature_free(SIGNATURE *sign) {
if (sign == NULL) {
return;
}
switch(sign->type) {
case SSH_KEYTYPE_DSS:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(sign->dsa_sign);
#elif defined HAVE_LIBCRYPTO
DSA_SIG_free(sign->dsa_sign);
#endif
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(sign->rsa_sign);
#elif defined HAVE_LIBCRYPTO
SAFE_FREE(sign->rsa_sign);
#endif
break;
default:
/* FIXME Passing NULL segfaults */
#if 0
ssh_log(NULL, SSH_LOG_RARE, "Freeing a signature with no type!\n"); */
#endif
break;
}
SAFE_FREE(sign);
}
#ifdef HAVE_LIBCRYPTO
/*
* Maybe the missing function from libcrypto
*
* I think now, maybe it's a bad idea to name it has it should have be
* named in libcrypto
*/
static ssh_string RSA_do_sign(const unsigned char *payload, int len, RSA *privkey) {
ssh_string sign = NULL;
unsigned char *buffer = NULL;
unsigned int size;
buffer = malloc(RSA_size(privkey));
if (buffer == NULL) {
return NULL;
}
if (RSA_sign(NID_sha1, payload, len, buffer, &size, privkey) == 0) {
SAFE_FREE(buffer);
return NULL;
}
sign = ssh_string_new(size);
if (sign == NULL) {
SAFE_FREE(buffer);
return NULL;
}
ssh_string_fill(sign, buffer, size);
SAFE_FREE(buffer);
return sign;
}
#endif
#ifndef _WIN32
ssh_string ssh_do_sign_with_agent(ssh_session session,
struct ssh_buffer_struct *buf, struct ssh_public_key_struct *publickey) {
struct ssh_buffer_struct *sigbuf = NULL;
struct ssh_string_struct *signature = NULL;
struct ssh_string_struct *session_id = NULL;
struct ssh_crypto_struct *crypto = NULL;
if (session->current_crypto) {
crypto = session->current_crypto;
} else {
crypto = session->next_crypto;
}
/* prepend session identifier */
session_id = ssh_string_new(SHA_DIGEST_LEN);
if (session_id == NULL) {
return NULL;
}
ssh_string_fill(session_id, crypto->session_id, SHA_DIGEST_LEN);
sigbuf = ssh_buffer_new();
if (sigbuf == NULL) {
ssh_string_free(session_id);
return NULL;
}
if (buffer_add_ssh_string(sigbuf, session_id) < 0) {
ssh_buffer_free(sigbuf);
ssh_string_free(session_id);
return NULL;
}
ssh_string_free(session_id);
/* append out buffer */
if (buffer_add_buffer(sigbuf, buf) < 0) {
ssh_buffer_free(sigbuf);
return NULL;
}
/* create signature */
signature = agent_sign_data(session, sigbuf, publickey);
ssh_buffer_free(sigbuf);
return signature;
}
#endif /* _WIN32 */
/*
* This function concats in a buffer the values needed to do a signature
* verification. */
ssh_buffer ssh_userauth_build_digest(ssh_session session, ssh_message msg, char *service) {
/*
The value of 'signature' is a signature by the corresponding private
key over the following data, in the following order:
string session identifier
byte SSH_MSG_USERAUTH_REQUEST
string user name
string service name
string "publickey"
boolean TRUE
string public key algorithm name
string public key to be used for authentication
*/
struct ssh_crypto_struct *crypto = session->current_crypto ? session->current_crypto :
session->next_crypto;
ssh_buffer buffer = NULL;
ssh_string session_id = NULL;
uint8_t type = SSH2_MSG_USERAUTH_REQUEST;
ssh_string username = ssh_string_from_char(msg->auth_request.username);
ssh_string servicename = ssh_string_from_char(service);
ssh_string method = ssh_string_from_char("publickey");
uint8_t has_sign = 1;
ssh_string algo = ssh_string_from_char(msg->auth_request.public_key->type_c);
ssh_string publickey = publickey_to_string(msg->auth_request.public_key);
buffer = ssh_buffer_new();
if (buffer == NULL) {
goto error;
}
session_id = ssh_string_new(SHA_DIGEST_LEN);
if (session_id == NULL) {
ssh_buffer_free(buffer);
buffer = NULL;
goto error;
}
ssh_string_fill(session_id, crypto->session_id, SHA_DIGEST_LEN);
if(buffer_add_ssh_string(buffer, session_id) < 0 ||
buffer_add_u8(buffer, type) < 0 ||
buffer_add_ssh_string(buffer, username) < 0 ||
buffer_add_ssh_string(buffer, servicename) < 0 ||
buffer_add_ssh_string(buffer, method) < 0 ||
buffer_add_u8(buffer, has_sign) < 0 ||
buffer_add_ssh_string(buffer, algo) < 0 ||
buffer_add_ssh_string(buffer, publickey) < 0) {
ssh_buffer_free(buffer);
buffer = NULL;
goto error;
}
error:
if(session_id) ssh_string_free(session_id);
if(username) ssh_string_free(username);
if(servicename) ssh_string_free(servicename);
if(method) ssh_string_free(method);
if(algo) ssh_string_free(algo);
if(publickey) ssh_string_free(publickey);
return buffer;
}
/*
* This function signs the session id (known as H) as a string then
* the content of sigbuf */
ssh_string ssh_do_sign(ssh_session session, ssh_buffer sigbuf,
ssh_private_key privatekey) {
struct ssh_crypto_struct *crypto = session->current_crypto ? session->current_crypto :
session->next_crypto;
unsigned char hash[SHA_DIGEST_LEN + 1] = {0};
ssh_string session_str = NULL;
ssh_string signature = NULL;
SIGNATURE *sign = NULL;
SHACTX ctx = NULL;
#ifdef HAVE_LIBGCRYPT
gcry_sexp_t gcryhash;
#endif
session_str = ssh_string_new(SHA_DIGEST_LEN);
if (session_str == NULL) {
return NULL;
}
ssh_string_fill(session_str, crypto->session_id, SHA_DIGEST_LEN);
ctx = sha1_init();
if (ctx == NULL) {
ssh_string_free(session_str);
return NULL;
}
sha1_update(ctx, session_str, ssh_string_len(session_str) + 4);
ssh_string_free(session_str);
sha1_update(ctx, buffer_get_rest(sigbuf), buffer_get_rest_len(sigbuf));
sha1_final(hash + 1,ctx);
hash[0] = 0;
#ifdef DEBUG_CRYPTO
ssh_print_hexa("Hash being signed with dsa", hash + 1, SHA_DIGEST_LEN);
#endif
sign = malloc(sizeof(SIGNATURE));
if (sign == NULL) {
return NULL;
}
switch(privatekey->type) {
case SSH_KEYTYPE_DSS:
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&gcryhash, NULL, "%b", SHA_DIGEST_LEN + 1, hash) ||
gcry_pk_sign(&sign->dsa_sign, gcryhash, privatekey->dsa_priv)) {
ssh_set_error(session, SSH_FATAL, "Signing: libcrypt error");
gcry_sexp_release(gcryhash);
signature_free(sign);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
sign->dsa_sign = DSA_do_sign(hash + 1, SHA_DIGEST_LEN,
privatekey->dsa_priv);
if (sign->dsa_sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Signing: openssl error");
signature_free(sign);
return NULL;
}
#ifdef DEBUG_CRYPTO
ssh_print_bignum("r", sign->dsa_sign->r);
ssh_print_bignum("s", sign->dsa_sign->s);
#endif
#endif /* HAVE_LIBCRYPTO */
sign->rsa_sign = NULL;
break;
case SSH_KEYTYPE_RSA:
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&gcryhash, NULL, "(data(flags pkcs1)(hash sha1 %b))",
SHA_DIGEST_LEN, hash + 1) ||
gcry_pk_sign(&sign->rsa_sign, gcryhash, privatekey->rsa_priv)) {
ssh_set_error(session, SSH_FATAL, "Signing: libcrypt error");
gcry_sexp_release(gcryhash);
signature_free(sign);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
sign->rsa_sign = RSA_do_sign(hash + 1, SHA_DIGEST_LEN,
privatekey->rsa_priv);
if (sign->rsa_sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Signing: openssl error");
signature_free(sign);
return NULL;
}
#endif
sign->dsa_sign = NULL;
break;
default:
return NULL;
}
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(gcryhash);
#endif
sign->type = privatekey->type;
signature = signature_to_string(sign);
signature_free(sign);
return signature;
}
ssh_string ssh_encrypt_rsa1(ssh_session session, ssh_string data, ssh_public_key key) {
ssh_string str = NULL;
size_t len = ssh_string_len(data);
size_t size = 0;
#ifdef HAVE_LIBGCRYPT
const char *tmp = NULL;
gcry_sexp_t ret_sexp;
gcry_sexp_t data_sexp;
if (gcry_sexp_build(&data_sexp, NULL, "(data(flags pkcs1)(value %b))",
len, ssh_string_data(data))) {
ssh_set_error(session, SSH_FATAL, "RSA1 encrypt: libgcrypt error");
return NULL;
}
if (gcry_pk_encrypt(&ret_sexp, data_sexp, key->rsa_pub)) {
gcry_sexp_release(data_sexp);
ssh_set_error(session, SSH_FATAL, "RSA1 encrypt: libgcrypt error");
return NULL;
}
gcry_sexp_release(data_sexp);
data_sexp = gcry_sexp_find_token(ret_sexp, "a", 0);
if (data_sexp == NULL) {
ssh_set_error(session, SSH_FATAL, "RSA1 encrypt: libgcrypt error");
gcry_sexp_release(ret_sexp);
return NULL;
}
tmp = gcry_sexp_nth_data(data_sexp, 1, &size);
if (*tmp == 0) {
size--;
tmp++;
}
str = ssh_string_new(size);
if (str == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
gcry_sexp_release(data_sexp);
gcry_sexp_release(ret_sexp);
return NULL;
}
ssh_string_fill(str, tmp, size);
gcry_sexp_release(data_sexp);
gcry_sexp_release(ret_sexp);
#elif defined HAVE_LIBCRYPTO
size = RSA_size(key->rsa_pub);
str = ssh_string_new(size);
if (str == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
return NULL;
}
if (RSA_public_encrypt(len, ssh_string_data(data), ssh_string_data(str), key->rsa_pub,
RSA_PKCS1_PADDING) < 0) {
ssh_string_free(str);
return NULL;
}
#endif
return str;
}
/* this function signs the session id */
ssh_string ssh_sign_session_id(ssh_session session, ssh_private_key privatekey) {
struct ssh_crypto_struct *crypto=session->current_crypto ? session->current_crypto :
session->next_crypto;
unsigned char hash[SHA_DIGEST_LEN + 1] = {0};
ssh_string signature = NULL;
SIGNATURE *sign = NULL;
SHACTX ctx = NULL;
#ifdef HAVE_LIBGCRYPT
gcry_sexp_t data_sexp;
#endif
ctx = sha1_init();
if (ctx == NULL) {
return NULL;
}
sha1_update(ctx,crypto->session_id,SHA_DIGEST_LEN);
sha1_final(hash + 1,ctx);
hash[0] = 0;
#ifdef DEBUG_CRYPTO
ssh_print_hexa("Hash being signed with dsa",hash+1,SHA_DIGEST_LEN);
#endif
sign = malloc(sizeof(SIGNATURE));
if (sign == NULL) {
return NULL;
}
switch(privatekey->type) {
case SSH_KEYTYPE_DSS:
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&data_sexp, NULL, "%b", SHA_DIGEST_LEN + 1, hash) ||
gcry_pk_sign(&sign->dsa_sign, data_sexp, privatekey->dsa_priv)) {
ssh_set_error(session, SSH_FATAL, "Signing: libgcrypt error");
gcry_sexp_release(data_sexp);
signature_free(sign);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
sign->dsa_sign = DSA_do_sign(hash + 1, SHA_DIGEST_LEN,
privatekey->dsa_priv);
if (sign->dsa_sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Signing: openssl error");
signature_free(sign);
return NULL;
}
#ifdef DEBUG_CRYPTO
ssh_print_bignum("r",sign->dsa_sign->r);
ssh_print_bignum("s",sign->dsa_sign->s);
#endif
#endif /* HAVE_LIBCRYPTO */
sign->rsa_sign = NULL;
break;
case SSH_KEYTYPE_RSA:
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&data_sexp, NULL, "(data(flags pkcs1)(hash sha1 %b))",
SHA_DIGEST_LEN, hash + 1) ||
gcry_pk_sign(&sign->rsa_sign, data_sexp, privatekey->rsa_priv)) {
ssh_set_error(session, SSH_FATAL, "Signing: libgcrypt error");
gcry_sexp_release(data_sexp);
signature_free(sign);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
sign->rsa_sign = RSA_do_sign(hash + 1, SHA_DIGEST_LEN,
privatekey->rsa_priv);
if (sign->rsa_sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Signing: openssl error");
signature_free(sign);
return NULL;
}
#endif
sign->dsa_sign = NULL;
break;
default:
return NULL;
}
#ifdef HAVE_LIBGCRYPT
gcry_sexp_release(data_sexp);
#endif
sign->type = privatekey->type;
signature = signature_to_string(sign);
signature_free(sign);
return signature;
}
/** @} */
/* vim: set ts=4 sw=4 et cindent: */
Показать git blame Копировать постоянную ссылку