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tmate-ssh-server/libssh/src/pki_gcrypt.c
Nicolas Viennot 0f7ccda4fb Adding libssh
2013-06-10 02:50:07 -04:00

1700 lines
46 KiB
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/*
* pki_gcrypt.c private and public key handling using gcrypt.
*
* This file is part of the SSH Library
*
* Copyright (c) 2003-2009 Aris Adamantiadis
* Copyright (c) 2009-2011 Andreas Schneider <asn@cryptomilk.org>
*
* 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 "config.h"
#ifdef HAVE_LIBGCRYPT
#include <string.h>
#include <stdlib.h>
#include <gcrypt.h>
#include <stdio.h>
#include "libssh/priv.h"
#include "libssh/buffer.h"
#include "libssh/session.h"
#include "libssh/wrapper.h"
#include "libssh/misc.h"
#include "libssh/pki.h"
#include "libssh/pki_priv.h"
#define MAXLINESIZE 80
#define RSA_HEADER_BEGIN "-----BEGIN RSA PRIVATE KEY-----"
#define RSA_HEADER_END "-----END RSA PRIVATE KEY-----"
#define DSA_HEADER_BEGIN "-----BEGIN DSA PRIVATE KEY-----"
#define DSA_HEADER_END "-----END DSA PRIVATE KEY-----"
#define MAX_KEY_SIZE 32
#define MAX_PASSPHRASE_SIZE 1024
#define ASN1_INTEGER 2
#define ASN1_SEQUENCE 48
#define PKCS5_SALT_LEN 8
static int load_iv(const char *header, unsigned char *iv, int iv_len) {
int i;
int j;
int k;
memset(iv, 0, iv_len);
for (i = 0; i < iv_len; i++) {
if ((header[2*i] >= '0') && (header[2*i] <= '9'))
j = header[2*i] - '0';
else if ((header[2*i] >= 'A') && (header[2*i] <= 'F'))
j = header[2*i] - 'A' + 10;
else if ((header[2*i] >= 'a') && (header[2*i] <= 'f'))
j = header[2*i] - 'a' + 10;
else
return -1;
if ((header[2*i+1] >= '0') && (header[2*i+1] <= '9'))
k = header[2*i+1] - '0';
else if ((header[2*i+1] >= 'A') && (header[2*i+1] <= 'F'))
k = header[2*i+1] - 'A' + 10;
else if ((header[2*i+1] >= 'a') && (header[2*i+1] <= 'f'))
k = header[2*i+1] - 'a' + 10;
else
return -1;
iv[i] = (j << 4) + k;
}
return 0;
}
static uint32_t char_to_u32(unsigned char *data, uint32_t size) {
uint32_t ret;
uint32_t i;
for (i = 0, ret = 0; i < size; ret = ret << 8, ret += data[i++])
;
return ret;
}
static uint32_t asn1_get_len(ssh_buffer buffer) {
uint32_t len;
unsigned char tmp[4];
if (buffer_get_data(buffer,tmp,1) == 0) {
return 0;
}
if (tmp[0] > 127) {
len = tmp[0] & 127;
if (len > 4) {
return 0; /* Length doesn't fit in u32. Can this really happen? */
}
if (buffer_get_data(buffer,tmp,len) == 0) {
return 0;
}
len = char_to_u32(tmp, len);
} else {
len = char_to_u32(tmp, 1);
}
return len;
}
static ssh_string asn1_get_int(ssh_buffer buffer) {
ssh_string str;
unsigned char type;
uint32_t size;
if (buffer_get_data(buffer, &type, 1) == 0 || type != ASN1_INTEGER) {
return NULL;
}
size = asn1_get_len(buffer);
if (size == 0) {
return NULL;
}
str = ssh_string_new(size);
if (str == NULL) {
return NULL;
}
if (buffer_get_data(buffer, ssh_string_data(str), size) == 0) {
ssh_string_free(str);
return NULL;
}
return str;
}
static int asn1_check_sequence(ssh_buffer buffer) {
unsigned char *j = NULL;
unsigned char tmp;
int i;
uint32_t size;
uint32_t padding;
if (buffer_get_data(buffer, &tmp, 1) == 0 || tmp != ASN1_SEQUENCE) {
return 0;
}
size = asn1_get_len(buffer);
if ((padding = ssh_buffer_get_len(buffer) - buffer->pos - size) > 0) {
for (i = ssh_buffer_get_len(buffer) - buffer->pos - size,
j = (unsigned char*)ssh_buffer_get_begin(buffer) + size + buffer->pos;
i;
i--, j++)
{
if (*j != padding) { /* padding is allowed */
return 0; /* but nothing else */
}
}
}
return 1;
}
static int passphrase_to_key(char *data, unsigned int datalen,
unsigned char *salt, unsigned char *key, unsigned int keylen) {
MD5CTX md;
unsigned char digest[MD5_DIGEST_LEN] = {0};
unsigned int i;
unsigned int j;
unsigned int md_not_empty;
for (j = 0, md_not_empty = 0; j < keylen; ) {
md = md5_init();
if (md == NULL) {
return -1;
}
if (md_not_empty) {
md5_update(md, digest, MD5_DIGEST_LEN);
} else {
md_not_empty = 1;
}
md5_update(md, data, datalen);
if (salt) {
md5_update(md, salt, PKCS5_SALT_LEN);
}
md5_final(digest, md);
for (i = 0; j < keylen && i < MD5_DIGEST_LEN; j++, i++) {
if (key) {
key[j] = digest[i];
}
}
}
return 0;
}
static int privatekey_decrypt(int algo, int mode, unsigned int key_len,
unsigned char *iv, unsigned int iv_len,
ssh_buffer data, ssh_auth_callback cb,
void *userdata,
const char *desc)
{
char passphrase[MAX_PASSPHRASE_SIZE] = {0};
unsigned char key[MAX_KEY_SIZE] = {0};
unsigned char *tmp = NULL;
gcry_cipher_hd_t cipher;
int rc = -1;
if (!algo) {
return -1;
}
if (cb) {
rc = (*cb)(desc, passphrase, MAX_PASSPHRASE_SIZE, 0, 0, userdata);
if (rc < 0) {
return -1;
}
} else if (cb == NULL && userdata != NULL) {
snprintf(passphrase, MAX_PASSPHRASE_SIZE, "%s", (char *) userdata);
}
if (passphrase_to_key(passphrase, strlen(passphrase), iv, key, key_len) < 0) {
return -1;
}
if (gcry_cipher_open(&cipher, algo, mode, 0)
|| gcry_cipher_setkey(cipher, key, key_len)
|| gcry_cipher_setiv(cipher, iv, iv_len)
|| (tmp = malloc(ssh_buffer_get_len(data) * sizeof (char))) == NULL
|| gcry_cipher_decrypt(cipher, tmp, ssh_buffer_get_len(data),
ssh_buffer_get_begin(data), ssh_buffer_get_len(data))) {
gcry_cipher_close(cipher);
return -1;
}
memcpy(ssh_buffer_get_begin(data), tmp, ssh_buffer_get_len(data));
SAFE_FREE(tmp);
gcry_cipher_close(cipher);
return 0;
}
static int privatekey_dek_header(const char *header, unsigned int header_len,
int *algo, int *mode, unsigned int *key_len, unsigned char **iv,
unsigned int *iv_len) {
unsigned int iv_pos;
if (header_len > 13 && !strncmp("DES-EDE3-CBC", header, 12))
{
*algo = GCRY_CIPHER_3DES;
iv_pos = 13;
*mode = GCRY_CIPHER_MODE_CBC;
*key_len = 24;
*iv_len = 8;
}
else if (header_len > 8 && !strncmp("DES-CBC", header, 7))
{
*algo = GCRY_CIPHER_DES;
iv_pos = 8;
*mode = GCRY_CIPHER_MODE_CBC;
*key_len = 8;
*iv_len = 8;
}
else if (header_len > 12 && !strncmp("AES-128-CBC", header, 11))
{
*algo = GCRY_CIPHER_AES128;
iv_pos = 12;
*mode = GCRY_CIPHER_MODE_CBC;
*key_len = 16;
*iv_len = 16;
}
else if (header_len > 12 && !strncmp("AES-192-CBC", header, 11))
{
*algo = GCRY_CIPHER_AES192;
iv_pos = 12;
*mode = GCRY_CIPHER_MODE_CBC;
*key_len = 24;
*iv_len = 16;
}
else if (header_len > 12 && !strncmp("AES-256-CBC", header, 11))
{
*algo = GCRY_CIPHER_AES256;
iv_pos = 12;
*mode = GCRY_CIPHER_MODE_CBC;
*key_len = 32;
*iv_len = 16;
} else {
return -1;
}
*iv = malloc(*iv_len);
if (*iv == NULL) {
return -1;
}
return load_iv(header + iv_pos, *iv, *iv_len);
}
#define get_next_line(p, len) { \
while(p[len] == '\n' || p[len] == '\r') /* skip empty lines */ \
len++; \
if(p[len] == '\0') /* EOL */ \
len = -1; \
else /* calculate length */ \
for(p += len, len = 0; p[len] && p[len] != '\n' \
&& p[len] != '\r'; len++); \
}
static ssh_buffer privatekey_string_to_buffer(const char *pkey, int type,
ssh_auth_callback cb, void *userdata, const char *desc) {
ssh_buffer buffer = NULL;
ssh_buffer out = NULL;
const char *p;
unsigned char *iv = NULL;
const char *header_begin;
const char *header_end;
unsigned int header_begin_size;
unsigned int header_end_size;
unsigned int key_len = 0;
unsigned int iv_len = 0;
int algo = 0;
int mode = 0;
int len;
buffer = ssh_buffer_new();
if (buffer == NULL) {
return NULL;
}
switch(type) {
case SSH_KEYTYPE_DSS:
header_begin = DSA_HEADER_BEGIN;
header_end = DSA_HEADER_END;
break;
case SSH_KEYTYPE_RSA:
header_begin = RSA_HEADER_BEGIN;
header_end = RSA_HEADER_END;
break;
default:
ssh_buffer_free(buffer);
return NULL;
}
header_begin_size = strlen(header_begin);
header_end_size = strlen(header_end);
p = pkey;
len = 0;
get_next_line(p, len);
while(len > 0 && strncmp(p, header_begin, header_begin_size)) {
/* skip line */
get_next_line(p, len);
}
if(len < 0) {
/* no header found */
return NULL;
}
/* skip header line */
get_next_line(p, len);
if (len > 11 && strncmp("Proc-Type: 4,ENCRYPTED", p, 11) == 0) {
/* skip line */
get_next_line(p, len);
if (len > 10 && strncmp("DEK-Info: ", p, 10) == 0) {
p += 10;
len = 0;
get_next_line(p, len);
if (privatekey_dek_header(p, len, &algo, &mode, &key_len,
&iv, &iv_len) < 0) {
ssh_buffer_free(buffer);
SAFE_FREE(iv);
return NULL;
}
} else {
ssh_buffer_free(buffer);
SAFE_FREE(iv);
return NULL;
}
} else {
if(len > 0) {
if (buffer_add_data(buffer, p, len) < 0) {
ssh_buffer_free(buffer);
SAFE_FREE(iv);
return NULL;
}
}
}
get_next_line(p, len);
while(len > 0 && strncmp(p, header_end, header_end_size) != 0) {
if (buffer_add_data(buffer, p, len) < 0) {
ssh_buffer_free(buffer);
SAFE_FREE(iv);
return NULL;
}
get_next_line(p, len);
}
if (len == -1 || strncmp(p, header_end, header_end_size) != 0) {
ssh_buffer_free(buffer);
SAFE_FREE(iv);
return NULL;
}
if (buffer_add_data(buffer, "\0", 1) < 0) {
ssh_buffer_free(buffer);
SAFE_FREE(iv);
return NULL;
}
out = base64_to_bin(ssh_buffer_get_begin(buffer));
ssh_buffer_free(buffer);
if (out == NULL) {
SAFE_FREE(iv);
return NULL;
}
if (algo) {
if (privatekey_decrypt(algo, mode, key_len, iv, iv_len, out,
cb, userdata, desc) < 0) {
ssh_buffer_free(out);
SAFE_FREE(iv);
return NULL;
}
}
SAFE_FREE(iv);
return out;
}
static int b64decode_rsa_privatekey(const char *pkey, gcry_sexp_t *r,
ssh_auth_callback cb, void *userdata, const char *desc) {
const unsigned char *data;
ssh_string n = NULL;
ssh_string e = NULL;
ssh_string d = NULL;
ssh_string p = NULL;
ssh_string q = NULL;
ssh_string unused1 = NULL;
ssh_string unused2 = NULL;
ssh_string u = NULL;
ssh_string v = NULL;
ssh_buffer buffer = NULL;
int rc = 1;
buffer = privatekey_string_to_buffer(pkey, SSH_KEYTYPE_RSA, cb, userdata, desc);
if (buffer == NULL) {
return 0;
}
if (!asn1_check_sequence(buffer)) {
ssh_buffer_free(buffer);
return 0;
}
v = asn1_get_int(buffer);
if (v == NULL) {
ssh_buffer_free(buffer);
return 0;
}
data = ssh_string_data(v);
if (ssh_string_len(v) != 1 || data[0] != 0) {
ssh_buffer_free(buffer);
return 0;
}
n = asn1_get_int(buffer);
e = asn1_get_int(buffer);
d = asn1_get_int(buffer);
q = asn1_get_int(buffer);
p = asn1_get_int(buffer);
unused1 = asn1_get_int(buffer);
unused2 = asn1_get_int(buffer);
u = asn1_get_int(buffer);
ssh_buffer_free(buffer);
if (n == NULL || e == NULL || d == NULL || p == NULL || q == NULL ||
unused1 == NULL || unused2 == NULL|| u == NULL) {
rc = 0;
goto error;
}
if (gcry_sexp_build(r, NULL,
"(private-key(rsa(n %b)(e %b)(d %b)(p %b)(q %b)(u %b)))",
ssh_string_len(n), ssh_string_data(n),
ssh_string_len(e), ssh_string_data(e),
ssh_string_len(d), ssh_string_data(d),
ssh_string_len(p), ssh_string_data(p),
ssh_string_len(q), ssh_string_data(q),
ssh_string_len(u), ssh_string_data(u))) {
rc = 0;
}
error:
ssh_string_free(n);
ssh_string_free(e);
ssh_string_free(d);
ssh_string_free(p);
ssh_string_free(q);
ssh_string_free(unused1);
ssh_string_free(unused2);
ssh_string_free(u);
ssh_string_free(v);
return rc;
}
static int b64decode_dsa_privatekey(const char *pkey, gcry_sexp_t *r, ssh_auth_callback cb,
void *userdata, const char *desc) {
const unsigned char *data;
ssh_buffer buffer = NULL;
ssh_string p = NULL;
ssh_string q = NULL;
ssh_string g = NULL;
ssh_string y = NULL;
ssh_string x = NULL;
ssh_string v = NULL;
int rc = 1;
buffer = privatekey_string_to_buffer(pkey, SSH_KEYTYPE_DSS, cb, userdata, desc);
if (buffer == NULL) {
return 0;
}
if (!asn1_check_sequence(buffer)) {
ssh_buffer_free(buffer);
return 0;
}
v = asn1_get_int(buffer);
if (v == NULL) {
ssh_buffer_free(buffer);
return 0;
}
data = ssh_string_data(v);
if (ssh_string_len(v) != 1 || data[0] != 0) {
ssh_buffer_free(buffer);
return 0;
}
p = asn1_get_int(buffer);
q = asn1_get_int(buffer);
g = asn1_get_int(buffer);
y = asn1_get_int(buffer);
x = asn1_get_int(buffer);
ssh_buffer_free(buffer);
if (p == NULL || q == NULL || g == NULL || y == NULL || x == NULL) {
rc = 0;
goto error;
}
if (gcry_sexp_build(r, NULL,
"(private-key(dsa(p %b)(q %b)(g %b)(y %b)(x %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_len(x), ssh_string_data(x))) {
rc = 0;
}
error:
ssh_string_free(p);
ssh_string_free(q);
ssh_string_free(g);
ssh_string_free(y);
ssh_string_free(x);
ssh_string_free(v);
return rc;
}
#ifdef HAVE_GCRYPT_ECC
int pki_key_ecdsa_nid_from_name(const char *name)
{
return -1;
}
#endif
ssh_key pki_private_key_from_base64(const char *b64_key,
const char *passphrase,
ssh_auth_callback auth_fn,
void *auth_data)
{
gcry_sexp_t dsa = NULL;
gcry_sexp_t rsa = NULL;
ssh_key key = NULL;
enum ssh_keytypes_e type;
int valid;
/* needed for gcrypt initialization */
if (ssh_init() < 0) {
return NULL;
}
type = pki_privatekey_type_from_string(b64_key);
if (type == SSH_KEYTYPE_UNKNOWN) {
ssh_pki_log("Unknown or invalid private key.");
return NULL;
}
switch (type) {
case SSH_KEYTYPE_DSS:
if (passphrase == NULL) {
if (auth_fn) {
valid = b64decode_dsa_privatekey(b64_key, &dsa, auth_fn,
auth_data, "Passphrase for private key:");
} else {
valid = b64decode_dsa_privatekey(b64_key, &dsa, NULL, NULL,
NULL);
}
} else {
valid = b64decode_dsa_privatekey(b64_key, &dsa, NULL, (void *)
passphrase, NULL);
}
if (!valid) {
ssh_pki_log("Parsing private key");
goto fail;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
if (passphrase == NULL) {
if (auth_fn) {
valid = b64decode_rsa_privatekey(b64_key, &rsa, auth_fn,
auth_data, "Passphrase for private key:");
} else {
valid = b64decode_rsa_privatekey(b64_key, &rsa, NULL, NULL,
NULL);
}
} else {
valid = b64decode_rsa_privatekey(b64_key, &rsa, NULL,
(void *)passphrase, NULL);
}
if (!valid) {
ssh_pki_log("Parsing private key");
goto fail;
}
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
ssh_pki_log("Unkown or invalid private key type %d", type);
return NULL;
}
key = ssh_key_new();
if (key == NULL) {
goto fail;
}
key->type = type;
key->type_c = ssh_key_type_to_char(type);
key->flags = SSH_KEY_FLAG_PRIVATE | SSH_KEY_FLAG_PUBLIC;
key->dsa = dsa;
key->rsa = rsa;
return key;
fail:
ssh_key_free(key);
gcry_sexp_release(dsa);
gcry_sexp_release(rsa);
return NULL;
}
int pki_pubkey_build_dss(ssh_key key,
ssh_string p,
ssh_string q,
ssh_string g,
ssh_string pubkey) {
gcry_sexp_build(&key->dsa, 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 == NULL) {
return SSH_ERROR;
}
return SSH_OK;
}
int pki_pubkey_build_rsa(ssh_key key,
ssh_string e,
ssh_string n) {
gcry_sexp_build(&key->rsa, 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 == NULL) {
return SSH_ERROR;
}
return SSH_OK;
}
#ifdef HAVE_GCRYPT_ECC
int pki_pubkey_build_ecdsa(ssh_key key, int nid, ssh_string e)
{
return -1;
}
#endif
ssh_key pki_key_dup(const ssh_key key, int demote)
{
ssh_key new;
gcry_sexp_t sexp;
gcry_error_t err;
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 x = NULL;
ssh_string e = NULL;
ssh_string n = NULL;
ssh_string d = NULL;
ssh_string u = NULL;
new = ssh_key_new();
if (new == NULL) {
return NULL;
}
new->type = key->type;
new->type_c = key->type_c;
if (demote) {
new->flags = SSH_KEY_FLAG_PUBLIC;
} else {
new->flags = key->flags;
}
switch(key->type) {
case SSH_KEYTYPE_DSS:
sexp = gcry_sexp_find_token(key->dsa, "p", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
p = ssh_string_new(size);
if (p == NULL) {
goto fail;
}
ssh_string_fill(p, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->dsa, "q", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
q = ssh_string_new(size);
if (q == NULL) {
goto fail;
}
ssh_string_fill(q, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->dsa, "g", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
g = ssh_string_new(size);
if (g == NULL) {
goto fail;
}
ssh_string_fill(g, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->dsa, "y", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
y = ssh_string_new(size);
if (y == NULL) {
goto fail;
}
ssh_string_fill(y, (char *)tmp, size);
gcry_sexp_release(sexp);
if (!demote && (key->flags & SSH_KEY_FLAG_PRIVATE)) {
sexp = gcry_sexp_find_token(key->dsa, "x", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
x = ssh_string_new(size);
if (x == NULL) {
goto fail;
}
ssh_string_fill(x, (char *)tmp, size);
gcry_sexp_release(sexp);
err = gcry_sexp_build(&new->dsa, NULL,
"(private-key(dsa(p %b)(q %b)(g %b)(y %b)(x %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_len(x), ssh_string_data(x));
} else {
err = gcry_sexp_build(&new->dsa, 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));
}
if (err) {
goto fail;
}
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(x);
ssh_string_free(x);
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
sexp = gcry_sexp_find_token(key->rsa, "e", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
e = ssh_string_new(size);
if (e == NULL) {
goto fail;
}
ssh_string_fill(e, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->rsa, "n", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
n = ssh_string_new(size);
if (n == NULL) {
goto fail;
}
ssh_string_fill(n, (char *)tmp, size);
gcry_sexp_release(sexp);
if (!demote && (key->flags & SSH_KEY_FLAG_PRIVATE)) {
sexp = gcry_sexp_find_token(key->rsa, "d", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
d = ssh_string_new(size);
if (e == NULL) {
goto fail;
}
ssh_string_fill(d, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->rsa, "p", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
p = ssh_string_new(size);
if (p == NULL) {
goto fail;
}
ssh_string_fill(p, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->rsa, "q", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
q = ssh_string_new(size);
if (q == NULL) {
goto fail;
}
ssh_string_fill(q, (char *)tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->rsa, "u", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
u = ssh_string_new(size);
if (u == NULL) {
goto fail;
}
ssh_string_fill(u, (char *)tmp, size);
gcry_sexp_release(sexp);
err = gcry_sexp_build(&new->rsa, NULL,
"(private-key(rsa(n %b)(e %b)(d %b)(p %b)(q %b)(u %b)))",
ssh_string_len(n), ssh_string_data(n),
ssh_string_len(e), ssh_string_data(e),
ssh_string_len(d), ssh_string_data(d),
ssh_string_len(p), ssh_string_data(p),
ssh_string_len(q), ssh_string_data(q),
ssh_string_len(u), ssh_string_data(u));
} else {
err = gcry_sexp_build(&new->rsa, 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 (err) {
goto fail;
}
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
ssh_string_burn(d);
ssh_string_free(d);
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(u);
ssh_string_free(u);
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
ssh_key_free(new);
return NULL;
}
return new;
fail:
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(x);
ssh_string_free(x);
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
ssh_string_burn(u);
ssh_string_free(u);
ssh_key_free(new);
return NULL;
}
static int pki_key_generate(ssh_key key, int parameter, const char *type_s, int type){
gcry_sexp_t parms;
int rc;
rc = gcry_sexp_build(&parms,
NULL,
"(genkey(%s(nbits %d)(transient-key)))",
type_s,
parameter);
if (rc != 0)
return SSH_ERROR;
if(type == SSH_KEYTYPE_RSA)
rc = gcry_pk_genkey(&key->rsa, parms);
else
rc = gcry_pk_genkey(&key->dsa, parms);
gcry_sexp_release(parms);
if (rc != 0)
return SSH_ERROR;
return SSH_OK;
}
int pki_key_generate_rsa(ssh_key key, int parameter){
return pki_key_generate(key, parameter, "rsa", SSH_KEYTYPE_RSA);
}
int pki_key_generate_dss(ssh_key key, int parameter){
return pki_key_generate(key, parameter, "dsa", SSH_KEYTYPE_DSS);
}
#ifdef HAVE_GCRYPT_ECC
int pki_key_generate_ecdsa(ssh_key key, int parameter) {
return -1;
}
#endif
static int _bignum_cmp(const gcry_sexp_t s1,
const gcry_sexp_t s2,
const char *what)
{
gcry_sexp_t sexp;
bignum b1;
bignum b2;
sexp = gcry_sexp_find_token(s1, what, 0);
if (sexp == NULL) {
return 1;
}
b1 = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG);
gcry_sexp_release(sexp);
if (b1 == NULL) {
return 1;
}
sexp = gcry_sexp_find_token(s2, what, 0);
if (sexp == NULL) {
return 1;
}
b2 = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG);
gcry_sexp_release(sexp);
if (b2 == NULL) {
return 1;
}
if (bignum_cmp(b1, b2) != 0) {
return 1;
}
return 0;
}
int pki_key_compare(const ssh_key k1,
const ssh_key k2,
enum ssh_keycmp_e what)
{
switch (k1->type) {
case SSH_KEYTYPE_DSS:
if (_bignum_cmp(k1->dsa, k2->dsa, "p") != 0) {
return 1;
}
if (_bignum_cmp(k1->dsa, k2->dsa, "q") != 0) {
return 1;
}
if (_bignum_cmp(k1->dsa, k2->dsa, "g") != 0) {
return 1;
}
if (_bignum_cmp(k1->dsa, k2->dsa, "y") != 0) {
return 1;
}
if (what == SSH_KEY_CMP_PRIVATE) {
if (_bignum_cmp(k1->dsa, k2->dsa, "x") != 0) {
return 1;
}
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
if (_bignum_cmp(k1->rsa, k2->rsa, "e") != 0) {
return 1;
}
if (_bignum_cmp(k1->rsa, k2->rsa, "n") != 0) {
return 1;
}
if (what == SSH_KEY_CMP_PRIVATE) {
if (_bignum_cmp(k1->rsa, k2->rsa, "d") != 0) {
return 1;
}
if (_bignum_cmp(k1->rsa, k2->rsa, "p") != 0) {
return 1;
}
if (_bignum_cmp(k1->rsa, k2->rsa, "q") != 0) {
return 1;
}
if (_bignum_cmp(k1->rsa, k2->rsa, "u") != 0) {
return 1;
}
}
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
return 1;
}
return 0;
}
ssh_string pki_publickey_to_blob(const ssh_key key)
{
ssh_buffer buffer;
ssh_string type_s;
ssh_string str = NULL;
ssh_string e = NULL;
ssh_string n = NULL;
ssh_string p = NULL;
ssh_string g = NULL;
ssh_string q = NULL;
const char *tmp = NULL;
size_t size;
gcry_sexp_t sexp;
int rc;
buffer = ssh_buffer_new();
if (buffer == NULL) {
return NULL;
}
type_s = ssh_string_from_char(key->type_c);
if (type_s == NULL) {
ssh_buffer_free(buffer);
return NULL;
}
rc = buffer_add_ssh_string(buffer, type_s);
string_free(type_s);
if (rc < 0) {
ssh_buffer_free(buffer);
return NULL;
}
switch (key->type) {
case SSH_KEYTYPE_DSS:
sexp = gcry_sexp_find_token(key->dsa, "p", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
p = ssh_string_new(size);
if (p == NULL) {
goto fail;
}
ssh_string_fill(p, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->dsa, "q", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
q = ssh_string_new(size);
if (q == NULL) {
goto fail;
}
ssh_string_fill(q, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->dsa, "g", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
g = ssh_string_new(size);
if (g == NULL) {
goto fail;
}
ssh_string_fill(g, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->dsa, "y", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
n = ssh_string_new(size);
if (n == NULL) {
goto fail;
}
ssh_string_fill(n, (char *) tmp, size);
if (buffer_add_ssh_string(buffer, p) < 0) {
goto fail;
}
if (buffer_add_ssh_string(buffer, q) < 0) {
goto fail;
}
if (buffer_add_ssh_string(buffer, g) < 0) {
goto fail;
}
if (buffer_add_ssh_string(buffer, n) < 0) {
goto fail;
}
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(n);
ssh_string_free(n);
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
sexp = gcry_sexp_find_token(key->rsa, "e", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
e = ssh_string_new(size);
if (e == NULL) {
goto fail;
}
ssh_string_fill(e, (char *) tmp, size);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(key->rsa, "n", 0);
if (sexp == NULL) {
goto fail;
}
tmp = gcry_sexp_nth_data(sexp, 1, &size);
n = ssh_string_new(size);
if (n == NULL) {
goto fail;
}
ssh_string_fill(n, (char *) tmp, size);
gcry_sexp_release(sexp);
if (buffer_add_ssh_string(buffer, e) < 0) {
goto fail;
}
if (buffer_add_ssh_string(buffer, n) < 0) {
goto fail;
}
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(n);
ssh_string_free(n);
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
goto fail;
}
str = ssh_string_new(buffer_get_rest_len(buffer));
if (str == NULL) {
goto fail;
}
rc = ssh_string_fill(str, buffer_get_rest(buffer), buffer_get_rest_len(buffer));
if (rc < 0) {
goto fail;
}
ssh_buffer_free(buffer);
return str;
fail:
ssh_buffer_free(buffer);
ssh_string_burn(str);
ssh_string_free(str);
ssh_string_burn(e);
ssh_string_free(e);
ssh_string_burn(p);
ssh_string_free(p);
ssh_string_burn(g);
ssh_string_free(g);
ssh_string_burn(q);
ssh_string_free(q);
ssh_string_burn(n);
ssh_string_free(n);
return NULL;
}
int pki_export_pubkey_rsa1(const ssh_key key,
const char *host,
char *rsa1,
size_t rsa1_len)
{
gcry_sexp_t sexp;
int rsa_size;
bignum b;
char *e, *n;
sexp = gcry_sexp_find_token(key->rsa, "e", 0);
if (sexp == NULL) {
return SSH_ERROR;
}
b = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG);
gcry_sexp_release(sexp);
if (b == NULL) {
return SSH_ERROR;
}
e = bignum_bn2dec(b);
sexp = gcry_sexp_find_token(key->rsa, "n", 0);
if (sexp == NULL) {
SAFE_FREE(e);
return SSH_ERROR;
}
b = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG);
gcry_sexp_release(sexp);
if (b == NULL) {
SAFE_FREE(e);
return SSH_ERROR;
}
n = bignum_bn2dec(b);
rsa_size = (gcry_pk_get_nbits(key->rsa) + 7) / 8;
snprintf(rsa1, rsa1_len,
"%s %d %s %s\n",
host, rsa_size << 3, e, n);
SAFE_FREE(e);
SAFE_FREE(n);
return SSH_OK;
}
ssh_string pki_signature_to_blob(const ssh_signature sig)
{
char buffer[40] = {0};
const char *r = NULL;
const char *s = NULL;
gcry_sexp_t sexp;
size_t size = 0;
ssh_string sig_blob = NULL;
switch(sig->type) {
case SSH_KEYTYPE_DSS:
sexp = gcry_sexp_find_token(sig->dsa_sig, "r", 0);
if (sexp == NULL) {
return NULL;
}
r = gcry_sexp_nth_data(sexp, 1, &size);
/* libgcrypt put 0 when first bit is set */
if (*r == 0) {
size--;
r++;
}
memcpy(buffer, r + size - 20, 20);
gcry_sexp_release(sexp);
sexp = gcry_sexp_find_token(sig->dsa_sig, "s", 0);
if (sexp == NULL) {
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);
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
sexp = gcry_sexp_find_token(sig->rsa_sig, "s", 0);
if (sexp == NULL) {
return NULL;
}
s = gcry_sexp_nth_data(sexp, 1, &size);
if (*s == 0) {
size--;
s++;
}
sig_blob = ssh_string_new(size);
if (sig_blob == NULL) {
return NULL;
}
ssh_string_fill(sig_blob, discard_const_p(char, s), size);
gcry_sexp_release(sexp);
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
ssh_pki_log("Unknown signature key type: %d", sig->type);
return NULL;
break;
}
return sig_blob;
}
ssh_signature pki_signature_from_blob(const ssh_key pubkey,
const ssh_string sig_blob,
enum ssh_keytypes_e type)
{
ssh_signature sig;
gcry_error_t err;
size_t len;
size_t rsalen;
sig = ssh_signature_new();
if (sig == NULL) {
return NULL;
}
sig->type = type;
len = ssh_string_len(sig_blob);
switch(type) {
case SSH_KEYTYPE_DSS:
/* 40 is the dual signature blob len. */
if (len != 40) {
ssh_pki_log("Signature has wrong size: %lu",
(unsigned long)len);
ssh_signature_free(sig);
return NULL;
}
#ifdef DEBUG_CRYPTO
ssh_pki_log("DSA signature len: %lu", (unsigned long)len);
ssh_print_hexa("DSA signature", ssh_string_data(sig_blob), len);
#endif
err = gcry_sexp_build(&sig->dsa_sig,
NULL,
"(sig-val(dsa(r %b)(s %b)))",
20,
ssh_string_data(sig_blob),
20,
(unsigned char *)ssh_string_data(sig_blob) + 20);
if (err) {
ssh_signature_free(sig);
return NULL;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
rsalen = (gcry_pk_get_nbits(pubkey->rsa) + 7) / 8;
if (len > rsalen) {
ssh_pki_log("Signature is to big size: %lu",
(unsigned long)len);
ssh_signature_free(sig);
return NULL;
}
if (len < rsalen) {
ssh_pki_log("RSA signature len %lu < %lu",
(unsigned long)len, (unsigned long)rsalen);
}
#ifdef DEBUG_CRYPTO
ssh_pki_log("RSA signature len: %lu", (unsigned long)len);
ssh_print_hexa("RSA signature", ssh_string_data(sig_blob), len);
#endif
err = gcry_sexp_build(&sig->rsa_sig,
NULL,
"(sig-val(rsa(s %b)))",
ssh_string_len(sig_blob),
ssh_string_data(sig_blob));
if (err) {
ssh_signature_free(sig);
return NULL;
}
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
ssh_pki_log("Unknown signature type");
return NULL;
}
return sig;
}
int pki_signature_verify(ssh_session session,
const ssh_signature sig,
const ssh_key key,
const unsigned char *hash,
size_t hlen)
{
unsigned char ghash[hlen + 1];
gcry_sexp_t sexp;
gcry_error_t err;
switch(key->type) {
case SSH_KEYTYPE_DSS:
/* That is to mark the number as positive */
if(hash[0] >= 0x80) {
memcpy(ghash + 1, hash, hlen);
ghash[0] = 0;
hash = ghash;
hlen += 1;
}
err = gcry_sexp_build(&sexp, NULL, "%b", hlen, hash);
if (err) {
ssh_set_error(session,
SSH_FATAL,
"DSA hash error: %s", gcry_strerror(err));
return SSH_ERROR;
}
err = gcry_pk_verify(sig->dsa_sig, sexp, key->dsa);
gcry_sexp_release(sexp);
if (err) {
ssh_set_error(session, SSH_FATAL, "Invalid DSA signature");
if (gcry_err_code(err) != GPG_ERR_BAD_SIGNATURE) {
ssh_set_error(session,
SSH_FATAL,
"DSA verify error: %s",
gcry_strerror(err));
}
return SSH_ERROR;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
err = gcry_sexp_build(&sexp,
NULL,
"(data(flags pkcs1)(hash sha1 %b))",
hlen, hash);
if (err) {
ssh_set_error(session,
SSH_FATAL,
"RSA hash error: %s",
gcry_strerror(err));
return SSH_ERROR;
}
err = gcry_pk_verify(sig->rsa_sig, sexp, key->rsa);
gcry_sexp_release(sexp);
if (err) {
ssh_set_error(session, SSH_FATAL, "Invalid RSA signature");
if (gcry_err_code(err) != GPG_ERR_BAD_SIGNATURE) {
ssh_set_error(session,
SSH_FATAL,
"RSA verify error: %s",
gcry_strerror(err));
}
return SSH_ERROR;
}
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
ssh_set_error(session, SSH_FATAL, "Unknown public key type");
return SSH_ERROR;
}
return SSH_OK;
}
ssh_signature pki_do_sign(const ssh_key privkey,
const unsigned char *hash,
size_t hlen) {
unsigned char ghash[hlen + 1];
ssh_signature sig;
gcry_sexp_t sexp;
gcry_error_t err;
sig = ssh_signature_new();
if (sig == NULL) {
return NULL;
}
sig->type = privkey->type;
switch (privkey->type) {
case SSH_KEYTYPE_DSS:
/* That is to mark the number as positive */
if(hash[0] >= 0x80) {
memcpy(ghash + 1, hash, hlen);
ghash[0] = 0;
hash = ghash;
hlen += 1;
}
err = gcry_sexp_build(&sexp, NULL, "%b", hlen, hash);
if (err) {
ssh_signature_free(sig);
return NULL;
}
err = gcry_pk_sign(&sig->dsa_sig, sexp, privkey->dsa);
gcry_sexp_release(sexp);
if (err) {
ssh_signature_free(sig);
return NULL;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
err = gcry_sexp_build(&sexp,
NULL,
"(data(flags pkcs1)(hash sha1 %b))",
hlen,
hash);
if (err) {
ssh_signature_free(sig);
return NULL;
}
err = gcry_pk_sign(&sig->rsa_sig, sexp, privkey->rsa);
gcry_sexp_release(sexp);
if (err) {
ssh_signature_free(sig);
return NULL;
}
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
ssh_signature_free(sig);
return NULL;
}
return sig;
}
#ifdef WITH_SERVER
ssh_signature pki_do_sign_sessionid(const ssh_key key,
const unsigned char *hash,
size_t hlen)
{
unsigned char ghash[hlen + 1];
ssh_signature sig;
gcry_sexp_t sexp;
gcry_error_t err;
sig = ssh_signature_new();
if (sig == NULL) {
return NULL;
}
sig->type = key->type;
switch(key->type) {
case SSH_KEYTYPE_DSS:
/* That is to mark the number as positive */
if(hash[0] >= 0x80) {
memcpy(ghash + 1, hash, hlen);
ghash[0] = 0;
hash = ghash;
hlen += 1;
}
err = gcry_sexp_build(&sexp, NULL, "%b", hlen, hash);
if (err) {
ssh_signature_free(sig);
return NULL;
}
err = gcry_pk_sign(&sig->dsa_sig, sexp, key->dsa);
gcry_sexp_release(sexp);
if (err) {
ssh_signature_free(sig);
return NULL;
}
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
err = gcry_sexp_build(&sexp,
NULL,
"(data(flags pkcs1)(hash sha1 %b))",
hlen,
hash);
if (err) {
ssh_signature_free(sig);
return NULL;
}
err = gcry_pk_sign(&sig->rsa_sig, sexp, key->rsa);
gcry_sexp_release(sexp);
if (err) {
ssh_signature_free(sig);
return NULL;
}
break;
case SSH_KEYTYPE_ECDSA:
case SSH_KEYTYPE_UNKNOWN:
return NULL;
}
return sig;
}
#endif /* WITH_SERVER */
#endif /* HAVE_LIBGCRYPT */
/* vim: set ts=4 sw=4 et cindent: */
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