Manoj Ampalam 351f141a6b 5-10 C1
2016-05-10 15:38:01 -07:00

399 lines
10 KiB
C

/*
* Author: Manoj Ampalam <manoj.ampalam@microsoft.com>
* ssh-agent implementation on Windows
*
* Copyright (c) 2015 Microsoft Corp.
* All rights reserved
*
* Microsoft openssh win32 port
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "agent.h"
#include "agent-request.h"
#include <sddl.h>
#define MAX_KEY_LENGTH 255
#define MAX_VALUE_NAME 16383
static int
get_user_root(struct agent_connection* con, HKEY *root){
int r = 0;
if (ImpersonateNamedPipeClient(con->connection) == FALSE)
return ERROR_INTERNAL_ERROR;
r = RegOpenCurrentUser(KEY_ALL_ACCESS, root);
RevertToSelf();
return r;
}
static int
convert_blob(struct agent_connection* con, const char *blob, DWORD blen, char **eblob, DWORD *eblen, int encrypt) {
int r = 0;
DATA_BLOB in, out;
if (ImpersonateNamedPipeClient(con->connection) == FALSE)
return ERROR_INTERNAL_ERROR;
in.cbData = blen;
in.pbData = (char*)blob;
out.cbData = 0;
out.pbData = NULL;
if (encrypt) {
if (!CryptProtectData(&in, NULL, NULL, 0, NULL, 0, &out)) {
r = GetLastError();
goto done;
}
}
else {
if (!CryptUnprotectData(&in, NULL, NULL, 0, NULL, 0, &out)) {
r = GetLastError();
goto done;
}
}
*eblob = malloc(out.cbData);
if (*eblob == NULL) {
r = ERROR_OUTOFMEMORY;
goto done;
}
memcpy(*eblob, out.pbData, out.cbData);
*eblen = out.cbData;
done:
if (out.pbData)
LocalFree(out.pbData);
RevertToSelf();
return r;
}
int
process_add_identity(struct sshbuf* request, struct sshbuf* response, struct agent_connection* con) {
struct sshkey* key = NULL;
int r = 0, r1 = 0, blob_len, eblob_len;
size_t comment_len, pubkey_blob_len;
u_char *pubkey_blob = NULL;
char *thumbprint = NULL, *comment;
const char *blob;
char* eblob = NULL;
HKEY reg = 0, sub = 0, user_root = 0;
PSECURITY_DESCRIPTOR sd = NULL;
wchar_t* str = L"O:SYG:BAD:P(A;;GA;;;SY)";
SECURITY_ATTRIBUTES sa;
ConvertStringSecurityDescriptorToSecurityDescriptorW(str, SDDL_REVISION_1, &sd, NULL);
sa.nLength = sizeof(sa);
sa.lpSecurityDescriptor = sd;
sa.bInheritHandle = FALSE;
blob = sshbuf_ptr(request);
if ((r = sshkey_private_deserialize(request, &key)) != 0)
goto done;
blob_len = (sshbuf_ptr(request) - blob) & 0xffffffff;
if ((r = sshkey_to_blob(key, &pubkey_blob, &pubkey_blob_len)) != 0)
goto done;
if ((r = convert_blob(con, blob, blob_len, &eblob, &eblob_len, 1)) != 0)
goto done;
if (((r = sshbuf_peek_string_direct(request, &comment, &comment_len)) != 0) ||
((thumbprint = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT, SSH_FP_DEFAULT)) == NULL) ||
((r = get_user_root(con, &user_root)) != 0) ||
((r = RegCreateKeyExW(user_root, SSHD_KEYS_ROOT, 0, 0, 0, KEY_WRITE, NULL, &reg, NULL)) != 0) ||
((r = RegCreateKeyExA(reg, thumbprint, 0, 0, 0, KEY_WRITE, NULL, &sub, NULL)) != 0) ||
((r = RegSetValueExW(sub, NULL, 0, REG_BINARY, eblob, eblob_len)) != 0) ||
((r = RegSetValueExW(sub, L"pub", 0, REG_BINARY, pubkey_blob, pubkey_blob_len)) != 0) ||
((r = RegSetValueExW(sub, L"type", 0, REG_DWORD, (BYTE*)&key->type, 4)) != 0) ||
((r = RegSetValueExW(sub, L"comment", 0, REG_BINARY, comment, comment_len)) != 0) )
goto done;
done:
/* TODO if r failed, delete reg entries*/
r1 = sshbuf_put_u8(response, (r==0) ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
if (eblob)
free(eblob);
if (sd)
LocalFree(sd);
if (key)
sshkey_free(key);
if (thumbprint)
free(thumbprint);
if (user_root)
RegCloseKey(user_root);
if (reg)
RegCloseKey(reg);
if (sub)
RegCloseKey(sub);
if (pubkey_blob)
free(pubkey_blob);
return r1;
}
static int sign_blob(const struct sshkey *pubkey, u_char ** sig, size_t *siglen,
const u_char *blob, size_t blen, u_int flags, struct agent_connection* con) {
HKEY reg = 0, sub = 0, user_root = 0;
int r = 0;
struct sshkey* prikey = NULL;
char *thumbprint = NULL, *regdata = NULL;
DWORD regdatalen = 0, keyblob_len = 0;;
struct sshbuf* tmpbuf = NULL;
char *keyblob = NULL;
regdata = malloc(4);
regdatalen = 4;
*sig = NULL;
*siglen = 0;
if ((thumbprint = sshkey_fingerprint(pubkey, SSH_FP_HASH_DEFAULT, SSH_FP_DEFAULT)) == NULL)
goto done;
if ((r = get_user_root(con, &user_root)) != 0)
goto done;
if ((r = RegOpenKeyExW(user_root, SSHD_KEYS_ROOT,
0, STANDARD_RIGHTS_READ | KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS, &reg)) != 0)
goto done;
if ((r = RegOpenKeyExA(reg, thumbprint, 0, STANDARD_RIGHTS_READ | KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS,
&sub)) != 0)
goto done;
if ((RegQueryValueExW(sub, NULL, 0, NULL, regdata, &regdatalen)) != ERROR_MORE_DATA) {
r = EOTHER;
goto done;
}
if ((regdata = malloc(regdatalen)) == NULL) {
r = ENOMEM;
goto done;
}
if ((r = RegQueryValueExW(sub, NULL, 0, NULL, regdata, &regdatalen)) != 0)
goto done;
if ((r = convert_blob(con, regdata, regdatalen, &keyblob, &keyblob_len, FALSE)) != 0)
goto done;
if ((tmpbuf = sshbuf_from(keyblob, keyblob_len)) == NULL) {
r = ENOMEM;
goto done;
}
if ( ((r = sshkey_private_deserialize(tmpbuf, &prikey)) != 0) ||
((r = sshkey_sign(prikey, sig, siglen, blob, blen, 0)) != 0) )
goto done;
done:
if (keyblob)
free(keyblob);
if (regdata)
free(regdata);
if (tmpbuf)
sshbuf_free(tmpbuf);
if (prikey)
sshkey_free(prikey);
if (thumbprint)
free(thumbprint);
if (user_root)
RegCloseKey(user_root);
if (reg)
RegCloseKey(reg);
if (sub)
RegCloseKey(sub);
return r;
}
int
process_sign_request(struct sshbuf* request, struct sshbuf* response, struct agent_connection* con) {
u_char *blob, *data, *signature = NULL;
size_t blen, dlen, slen = 0;
u_int flags = 0;
int r, r1;
struct sshkey *key;
if ((r = sshbuf_get_string(request, &blob, &blen)) != 0 ||
(r = sshbuf_get_string(request, &data, &dlen)) != 0 ||
(r = sshbuf_get_u32(request, &flags)) != 0)
goto done;
/* TODO - flags?*/
if (((r = sshkey_from_blob(blob, blen, &key)) != 0)
|| ((r = sign_blob(key, &signature, &slen,
data, dlen, 0, con)) != 0))
goto done;
done:
if (r == 0) {
if ((r = sshbuf_put_u8(response, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
(r = sshbuf_put_string(response, signature, slen)) != 0) {
}
}
else
r = sshbuf_put_u8(response, SSH_AGENT_FAILURE);
free(data);
free(blob);
free(signature);
return r;
}
int
process_request_identities(struct sshbuf* request, struct sshbuf* response, struct agent_connection* con) {
int r, r1, count = 0, index = 0;
HKEY root = NULL, sub = NULL, user_root = 0;
char* count_ptr = NULL;
wchar_t sub_name[MAX_KEY_LENGTH];
DWORD sub_name_len = MAX_KEY_LENGTH;
char *regdata = NULL;
DWORD regdatalen = 0, key_count = 0;
struct sshbuf* identities;
regdata = malloc(4);
regdatalen = 4;
identities = sshbuf_new();
if ((identities == NULL) || (regdata == NULL))
goto done;
if ((r = get_user_root(con, &user_root)) != 0)
goto done;
if ((r = RegOpenKeyExW(user_root, SSHD_KEYS_ROOT,
0, STANDARD_RIGHTS_READ | KEY_ENUMERATE_SUB_KEYS, &root)) != 0)
goto done;
while (1) {
sub_name_len = MAX_KEY_LENGTH;
if (sub) {
RegCloseKey(sub);
sub = NULL;
}
if ((r = RegEnumKeyExW(root, index++, sub_name, &sub_name_len, NULL, NULL, NULL, NULL)) == 0) {
if ((r = RegOpenKeyExW(root, sub_name, 0, KEY_QUERY_VALUE, &sub)) == 0) {
if ((r = RegQueryValueExW(sub, L"pub", 0, NULL, regdata, &regdatalen)) != 0) {
if (r == ERROR_MORE_DATA) {
r = 0;
if (regdata)
free(regdata);
if ((regdata = malloc(regdatalen)) == NULL) {
r = ENOMEM;
goto done;
}
if ((r = RegQueryValueExW(sub, L"pub", 0, NULL, regdata, &regdatalen)) != 0)
goto done;
}
else {
r = EOTHER;
goto done;
}
}
if ((r = sshbuf_put_string(identities, regdata, regdatalen)) != 0)
goto done;
if ((r = RegQueryValueExW(sub, L"comment", 0, NULL, regdata, &regdatalen)) != 0) {
if (r == ERROR_MORE_DATA) {
r = 0;
if (regdata)
free(regdata);
if ((regdata = malloc(regdatalen)) == NULL) {
r = ENOMEM;
goto done;
}
if ((r = RegQueryValueExW(sub, L"comment", 0, NULL, regdata, &regdatalen)) != 0)
goto done;
}
else {
r = EOTHER;
goto done;
}
}
if ((r = sshbuf_put_string(identities, regdata, regdatalen)) != 0)
goto done;
key_count++;
}
else if (r == ERROR_FILE_NOT_FOUND) {
r = 0;
continue;
}
else
goto done;
}
else if (r == ERROR_NO_MORE_ITEMS) {
r = 0;
break;
}
else
goto done;
}
if (((r = sshbuf_put_u8(response, SSH2_AGENT_IDENTITIES_ANSWER)) != 0)
|| ((r = sshbuf_put_u32(response, key_count)) != 0)
|| ((r = sshbuf_putb(response, identities)) != 0))
goto done;
done:
if (regdata)
free(regdata);
if (identities)
sshbuf_free(identities);
if (user_root)
RegCloseKey(user_root);
if (root)
RegCloseKey(root);
if (sub)
RegCloseKey(sub);
return r;
}
int process_keyagent_request(struct sshbuf* request, struct sshbuf* response, struct agent_connection* con) {
int r;
u_char type;
if ((r = sshbuf_get_u8(request, &type)) != 0)
return r;
switch (type) {
case SSH2_AGENTC_ADD_IDENTITY:
return process_add_identity(request, response, con);
case SSH2_AGENTC_REQUEST_IDENTITIES:
return process_request_identities(request, response, con);
case SSH2_AGENTC_SIGN_REQUEST:
return process_sign_request(request, response, con);
default:
return EINVAL;
}
}