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GUAC-1171: Migrate to common SSH within client.

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This commit is contained in:
Michael Jumper 2015-07-10 12:43:35 -07:00
parent 98503a9fb7
commit 0fcea2738b
9 changed files with 121 additions and 867 deletions
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8
src/protocols/ssh/Makefile.am
View File

@ -30,18 +30,14 @@ libguac_client_ssh_la_SOURCES = \
clipboard.c \
guac_handlers.c \
sftp.c \
ssh_buffer.c \
ssh_client.c \
ssh_key.c
ssh_client.c
noinst_HEADERS = \
client.h \
clipboard.h \
guac_handlers.h \
sftp.h \
ssh_buffer.h \
ssh_client.h \
ssh_key.h
ssh_client.h
# Add agent sources if enabled
if ENABLE_SSH_AGENT

1
src/protocols/ssh/client.c
View File

@ -142,7 +142,6 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
strcpy(client_data->password, argv[IDX_PASSWORD]);
/* Init public key auth information */
client_data->key = NULL;
strcpy(client_data->key_base64, argv[IDX_PRIVATE_KEY]);
strcpy(client_data->key_passphrase, argv[IDX_PASSPHRASE]);

11
src/protocols/ssh/client.h
View File

@ -26,8 +26,8 @@
#include "config.h"
#include "guac_ssh.h"
#include "sftp.h"
#include "ssh_key.h"
#include "terminal.h"
#include <libssh2.h>
@ -77,11 +77,6 @@ typedef struct ssh_guac_client_data {
*/
char key_passphrase[1024];
/**
* The private key to use for authentication, if any.
*/
ssh_key* key;
/**
* The name of the font to use for display rendering.
*/
@ -117,12 +112,12 @@ typedef struct ssh_guac_client_data {
/**
* SSH session, used by the SSH client thread.
*/
LIBSSH2_SESSION* session;
guac_common_ssh_session* session;
/**
* The distinct SSH session used for SFTP.
*/
LIBSSH2_SESSION* sftp_ssh_session;
guac_common_ssh_session* sftp_ssh_session;
/**
* SFTP session, used for file transfers.

15
src/protocols/ssh/guac_handlers.c
View File

@ -24,7 +24,7 @@
#include "client.h"
#include "guac_handlers.h"
#include "ssh_key.h"
#include "guac_ssh.h"
#include "terminal.h"
#include <cairo/cairo.h>
@ -106,10 +106,8 @@ int ssh_guac_client_free_handler(guac_client* client) {
libssh2_sftp_shutdown(guac_client_data->sftp_session);
/* Disconnect SSH session corresponding to the SFTP session */
if (guac_client_data->sftp_ssh_session) {
libssh2_session_disconnect(guac_client_data->sftp_ssh_session, "Bye");
libssh2_session_free(guac_client_data->sftp_ssh_session);
}
if (guac_client_data->sftp_ssh_session)
guac_common_ssh_destroy_session(guac_client_data->sftp_ssh_session);
/* Clean up the SFTP filesystem object */
if (guac_client_data->sftp_filesystem)
@ -117,15 +115,12 @@ int ssh_guac_client_free_handler(guac_client* client) {
/* Free session */
if (guac_client_data->session != NULL)
libssh2_session_free(guac_client_data->session);
/* Free auth key */
if (guac_client_data->key != NULL)
ssh_key_free(guac_client_data->key);
guac_common_ssh_destroy_session(guac_client_data->session);
/* Free generic data struct */
free(client->data);
guac_common_ssh_uninit();
return 0;
}

136
src/protocols/ssh/ssh_buffer.c
View File

@ -1,136 +0,0 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config.h"
#include <openssl/bn.h>
#include <openssl/ossl_typ.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
void buffer_write_byte(char** buffer, uint8_t value) {
uint8_t* data = (uint8_t*) *buffer;
*data = value;
(*buffer)++;
}
void buffer_write_uint32(char** buffer, uint32_t value) {
uint8_t* data = (uint8_t*) *buffer;
data[0] = (value & 0xFF000000) >> 24;
data[1] = (value & 0x00FF0000) >> 16;
data[2] = (value & 0x0000FF00) >> 8;
data[3] = value & 0x000000FF;
*buffer += 4;
}
void buffer_write_data(char** buffer, const char* data, int length) {
memcpy(*buffer, data, length);
*buffer += length;
}
void buffer_write_bignum(char** buffer, BIGNUM* value) {
unsigned char* bn_buffer;
int length;
/* If zero, just write zero length */
if (BN_is_zero(value)) {
buffer_write_uint32(buffer, 0);
return;
}
/* Allocate output buffer, add padding byte */
length = BN_num_bytes(value);
bn_buffer = malloc(length);
/* Convert BIGNUM */
BN_bn2bin(value, bn_buffer);
/* If first byte has high bit set, write padding byte */
if (bn_buffer[0] & 0x80) {
buffer_write_uint32(buffer, length+1);
buffer_write_byte(buffer, 0);
}
else
buffer_write_uint32(buffer, length);
/* Write data */
memcpy(*buffer, bn_buffer, length);
*buffer += length;
free(bn_buffer);
}
void buffer_write_string(char** buffer, const char* string, int length) {
buffer_write_uint32(buffer, length);
buffer_write_data(buffer, string, length);
}
uint8_t buffer_read_byte(char** buffer) {
uint8_t* data = (uint8_t*) *buffer;
uint8_t value = *data;
(*buffer)++;
return value;
}
uint32_t buffer_read_uint32(char** buffer) {
uint8_t* data = (uint8_t*) *buffer;
uint32_t value =
(data[0] << 24)
| (data[1] << 16)
| (data[2] << 8)
| data[3];
*buffer += 4;
return value;
}
char* buffer_read_string(char** buffer, int* length) {
char* value;
*length = buffer_read_uint32(buffer);
value = *buffer;
*buffer += *length;
return value;
}

82
src/protocols/ssh/ssh_buffer.h
View File

@ -1,82 +0,0 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef _GUAC_SSH_BUFFER_H
#define _GUAC_SSH_BUFFER_H
#include "config.h"
#include <openssl/bn.h>
#include <stdint.h>
/**
* Writes the given byte to the given buffer, advancing the buffer pointer by
* one byte.
*/
void buffer_write_byte(char** buffer, uint8_t value);
/**
* Writes the given integer to the given buffer, advancing the buffer pointer
* four bytes.
*/
void buffer_write_uint32(char** buffer, uint32_t value);
/**
* Writes the given string and its length to the given buffer, advancing the
* buffer pointer by the size of the length (four bytes) and the size of the
* string.
*/
void buffer_write_string(char** buffer, const char* string, int length);
/**
* Writes the given BIGNUM the given buffer, advancing the buffer pointer by
* the size of the length (four bytes) and the size of the BIGNUM.
*/
void buffer_write_bignum(char** buffer, BIGNUM* value);
/**
* Writes the given data the given buffer, advancing the buffer pointer by the
* given length.
*/
void buffer_write_data(char** buffer, const char* data, int length);
/**
* Reads a single byte from the given buffer, advancing the buffer by one byte.
*/
uint8_t buffer_read_byte(char** buffer);
/**
* Reads an integer from the given buffer, advancing the buffer by four bytes.
*/
uint32_t buffer_read_uint32(char** buffer);
/**
* Reads a string and its length from the given buffer, advancing the buffer
* by the size of the length (four bytes) and the size of the string, and
* returning a pointer to the buffer. The length of the string is stored in
* the given int.
*/
char* buffer_read_string(char** buffer, int* length);
#endif

382
src/protocols/ssh/ssh_client.c
View File

@ -25,7 +25,6 @@
#include "client.h"
#include "guac_ssh.h"
#include "sftp.h"
#include "ssh_key.h"
#include "terminal.h"
#ifdef ENABLE_SSH_AGENT
@ -57,6 +56,96 @@
#include <sys/socket.h>
#include <sys/time.h>
/**
* Produces a new user object containing a username and password or private
* key, prompting the user as necessary to obtain that information.
*
* @param client
* The Guacamole client containing any existing user data, as well as the
* terminal to use when prompting the user.
*
* @return
* A new user object containing the user's username and other credentials.
*/
static guac_common_ssh_user* guac_ssh_get_user(guac_client* client) {
ssh_guac_client_data* client_data = (ssh_guac_client_data*) client->data;
guac_common_ssh_user* user;
/* Get username */
if (client_data->username[0] == 0)
guac_terminal_prompt(client_data->term, "Login as: ",
client_data->username, sizeof(client_data->username), true);
/* Create user object from username */
user = guac_common_ssh_create_user(client_data->username);
/* If key specified, import */
if (client_data->key_base64[0] != 0) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Attempting private key import (WITHOUT passphrase)");
/* Attempt to read key without passphrase */
if (guac_common_ssh_user_import_key(user,
client_data->key_base64, NULL)) {
/* Log failure of initial attempt */
guac_client_log(client, GUAC_LOG_DEBUG,
"Initial import failed: %s",
guac_common_ssh_key_error());
guac_client_log(client, GUAC_LOG_DEBUG,
"Re-attempting private key import (WITH passphrase)");
/* Prompt for passphrase if missing */
if (client_data->key_passphrase[0] == 0)
guac_terminal_prompt(client_data->term, "Key passphrase: ",
client_data->key_passphrase,
sizeof(client_data->key_passphrase), false);
/* Reattempt import with passphrase */
if (guac_common_ssh_user_import_key(user,
client_data->key_base64,
client_data->key_passphrase)) {
/* If still failing, give up */
guac_client_abort(client,
GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Auth key import failed: %s",
guac_common_ssh_key_error());
guac_common_ssh_destroy_user(user);
return NULL;
}
} /* end decrypt key with passphrase */
/* Success */
guac_client_log(client, GUAC_LOG_INFO,
"Auth key successfully imported.");
} /* end if key given */
/* Otherwise, get password if not provided */
else if (client_data->password[0] == 0) {
guac_terminal_prompt(client_data->term, "Password: ",
client_data->password, sizeof(client_data->password), false);
guac_common_ssh_user_set_password(user, client_data->password);
}
/* Clear screen of any prompts */
guac_terminal_printf(client_data->term, "\x1B[H\x1B[J");
return user;
}
void* ssh_input_thread(void* data) {
guac_client* client = (guac_client*) data;
@ -76,213 +165,13 @@ void* ssh_input_thread(void* data) {
}
static int __sign_callback(LIBSSH2_SESSION* session,
unsigned char** sig, size_t* sig_len,
const unsigned char* data, size_t data_len, void **abstract) {
ssh_key* key = (ssh_key*) abstract;
int length;
/* Allocate space for signature */
*sig = malloc(4096);
/* Sign with key */
length = ssh_key_sign(key, (const char*) data, data_len, *sig);
if (length < 0)
return 1;
*sig_len = length;
return 0;
}
/**
* Callback for the keyboard-interactive authentication method. Currently
* suports just one prompt for the password.
*/
static void __kbd_callback(const char *name, int name_len,
const char *instruction, int instruction_len,
int num_prompts,
const LIBSSH2_USERAUTH_KBDINT_PROMPT *prompts,
LIBSSH2_USERAUTH_KBDINT_RESPONSE *responses,
void **abstract) {
guac_client* client = (guac_client*) *abstract;
ssh_guac_client_data* client_data = (ssh_guac_client_data*) client->data;
if (num_prompts == 1) {
responses[0].text = strdup(client_data->password);
responses[0].length = strlen(client_data->password);
}
else
guac_client_log(client, GUAC_LOG_WARNING,
"Unsupported number of keyboard-interactive prompts: %i",
num_prompts);
}
static LIBSSH2_SESSION* __guac_ssh_create_session(guac_client* client,
int* socket_fd) {
int retval;
int fd;
struct addrinfo* addresses;
struct addrinfo* current_address;
char connected_address[1024];
char connected_port[64];
char *user_authlist;
ssh_guac_client_data* client_data = (ssh_guac_client_data*) client->data;
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP
};
/* Get socket */
fd = socket(AF_INET, SOCK_STREAM, 0);
/* Get addresses connection */
if ((retval = getaddrinfo(client_data->hostname, client_data->port,
&hints, &addresses))) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error parsing given address or port: %s",
gai_strerror(retval));
return NULL;
}
/* Attempt connection to each address until success */
current_address = addresses;
while (current_address != NULL) {
int retval;
/* Resolve hostname */
if ((retval = getnameinfo(current_address->ai_addr,
current_address->ai_addrlen,
connected_address, sizeof(connected_address),
connected_port, sizeof(connected_port),
NI_NUMERICHOST | NI_NUMERICSERV)))
guac_client_log(client, GUAC_LOG_DEBUG, "Unable to resolve host: %s", gai_strerror(retval));
/* Connect */
if (connect(fd, current_address->ai_addr,
current_address->ai_addrlen) == 0) {
guac_client_log(client, GUAC_LOG_DEBUG, "Successfully connected to "
"host %s, port %s", connected_address, connected_port);
/* Done if successful connect */
break;
}
/* Otherwise log information regarding bind failure */
else
guac_client_log(client, GUAC_LOG_DEBUG, "Unable to connect to "
"host %s, port %s: %s",
connected_address, connected_port, strerror(errno));
current_address = current_address->ai_next;
}
/* If unable to connect to anything, fail */
if (current_address == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to connect to any addresses.");
return NULL;
}
/* Free addrinfo */
freeaddrinfo(addresses);
/* Open SSH session */
LIBSSH2_SESSION* session = libssh2_session_init_ex(NULL, NULL,
NULL, client);
if (session == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Session allocation failed.");
return NULL;
}
/* Perform handshake */
if (libssh2_session_handshake(session, fd)) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "SSH handshake failed.");
return NULL;
}
/* Save file descriptor */
if (socket_fd != NULL)
*socket_fd = fd;
/* Get list of suported authentication methods */
user_authlist = libssh2_userauth_list(session, client_data->username, strlen(client_data->username));
guac_client_log(client, GUAC_LOG_DEBUG, "Supported authentication methods: %s", user_authlist);
/* Authenticate with key if available */
if (client_data->key != NULL) {
/* Check if public key auth is suported on the server */
if (strstr(user_authlist, "publickey") == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Public key authentication not suported");
return NULL;
}
if (!libssh2_userauth_publickey(session, client_data->username,
(unsigned char*) client_data->key->public_key,
client_data->key->public_key_length,
__sign_callback, (void**) client_data->key))
return session;
else {
char* error_message;
libssh2_session_last_error(session, &error_message, NULL, 0);
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Public key authentication failed: %s", error_message);
return NULL;
}
}
/* Authenticate with password */
if (strstr(user_authlist, "password") != NULL) {
guac_client_log(client, GUAC_LOG_DEBUG, "Using password authentication method");
retval = libssh2_userauth_password(session, client_data->username, client_data->password);
}
else if (strstr(user_authlist, "keyboard-interactive") != NULL) {
guac_client_log(client, GUAC_LOG_DEBUG, "Using keyboard-interactive authentication method");
retval = libssh2_userauth_keyboard_interactive(session, client_data->username, &__kbd_callback);
}
else {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_BAD_TYPE, "No known authentication methods");
return NULL;
}
if (retval == 0)
return session;
else {
char* error_message;
libssh2_session_last_error(session, &error_message, NULL, 0);
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Password authentication failed: %s", error_message);
return NULL;
}
}
void* ssh_client_thread(void* data) {
guac_client* client = (guac_client*) data;
ssh_guac_client_data* client_data = (ssh_guac_client_data*) client->data;
char name[1024];
guac_socket* socket = client->socket;
char buffer[8192];
int bytes_read = -1234;
int socket_fd;
pthread_t input_thread;
@ -290,81 +179,31 @@ void* ssh_client_thread(void* data) {
if (guac_common_ssh_init(client))
return NULL;
/* Get username */
if (client_data->username[0] == 0)
guac_terminal_prompt(client_data->term, "Login as: ",
client_data->username, sizeof(client_data->username), true);
/* Get user and credentials */
guac_common_ssh_user* user = guac_ssh_get_user(client);
/* Send new name */
snprintf(name, sizeof(name)-1, "%s@%s", client_data->username, client_data->hostname);
char name[1024];
snprintf(name, sizeof(name)-1, "%s@%s",
client_data->username, client_data->hostname);
guac_protocol_send_name(socket, name);
/* If key specified, import */
if (client_data->key_base64[0] != 0) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Attempting private key import (WITHOUT passphrase)");
/* Attempt to read key without passphrase */
client_data->key = ssh_key_alloc(client_data->key_base64,
strlen(client_data->key_base64), "");
/* On failure, attempt with passphrase */
if (client_data->key == NULL) {
/* Log failure of initial attempt */
guac_client_log(client, GUAC_LOG_DEBUG,
"Initial import failed: %s", ssh_key_error());
guac_client_log(client, GUAC_LOG_DEBUG,
"Re-attempting private key import (WITH passphrase)");
/* Prompt for passphrase if missing */
if (client_data->key_passphrase[0] == 0)
guac_terminal_prompt(client_data->term, "Key passphrase: ",
client_data->key_passphrase, sizeof(client_data->key_passphrase), false);
/* Import key with passphrase */
client_data->key = ssh_key_alloc(client_data->key_base64,
strlen(client_data->key_base64),
client_data->key_passphrase);
/* If still failing, give up */
if (client_data->key == NULL) {
guac_client_abort(client,
GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Auth key import failed: %s", ssh_key_error());
return NULL;
}
} /* end decrypt key with passphrase */
/* Success */
guac_client_log(client, GUAC_LOG_INFO, "Auth key successfully imported.");
} /* end if key given */
/* Otherwise, get password if not provided */
else if (client_data->password[0] == 0)
guac_terminal_prompt(client_data->term, "Password: ",
client_data->password, sizeof(client_data->password), false);
/* Clear screen */
guac_terminal_printf(client_data->term, "\x1B[H\x1B[J");
/* Open SSH session */
client_data->session = __guac_ssh_create_session(client, &socket_fd);
client_data->session = guac_common_ssh_create_session(client,
client_data->hostname, client_data->port, user);
if (client_data->session == NULL) {
/* Already aborted within __guac_ssh_create_session() */
/* Already aborted within guac_common_ssh_create_session() */
return NULL;
}
pthread_mutex_init(&client_data->term_channel_lock, NULL);
/* Open channel for terminal */
client_data->term_channel = libssh2_channel_open_session(client_data->session);
client_data->term_channel =
libssh2_channel_open_session(client_data->session->session);
if (client_data->term_channel == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to open terminal channel.");
guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
"Unable to open terminal channel.");
return NULL;
}
@ -393,14 +232,15 @@ void* ssh_client_thread(void* data) {
/* Create SSH session specific for SFTP */
guac_client_log(client, GUAC_LOG_DEBUG, "Reconnecting for SFTP...");
client_data->sftp_ssh_session = __guac_ssh_create_session(client, NULL);
client_data->sftp_ssh_session = guac_common_ssh_create_session(client,
client_data->hostname, client_data->port, user);
if (client_data->sftp_ssh_session == NULL) {
/* Already aborted within __guac_ssh_create_session() */
/* Already aborted within guac_common_ssh_create_session() */
return NULL;
}
/* Request SFTP */
client_data->sftp_session = libssh2_sftp_init(client_data->sftp_ssh_session);
client_data->sftp_session = libssh2_sftp_init(client_data->sftp_ssh_session->session);
if (client_data->sftp_session == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to start SFTP session.");
return NULL;
@ -439,10 +279,10 @@ void* ssh_client_thread(void* data) {
}
/* Set non-blocking */
libssh2_session_set_blocking(client_data->session, 0);
libssh2_session_set_blocking(client_data->session->session, 0);
/* While data available, write to terminal */
bytes_read = 0;
int bytes_read = 0;
for (;;) {
/* Track total amount of data read */
@ -491,13 +331,14 @@ void* ssh_client_thread(void* data) {
struct timeval timeout;
FD_ZERO(&fds);
FD_SET(socket_fd, &fds);
FD_SET(client_data->session->fd, &fds);
/* Wait for one second */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
if (select(socket_fd+1, &fds, NULL, NULL, &timeout) < 0)
if (select(client_data->session->fd + 1, &fds,
NULL, NULL, &timeout) < 0)
break;
}
@ -508,7 +349,6 @@ void* ssh_client_thread(void* data) {
pthread_join(input_thread, NULL);
pthread_mutex_destroy(&client_data->term_channel_lock);
guac_common_ssh_uninit();
guac_client_log(client, GUAC_LOG_INFO, "SSH connection ended.");
return NULL;

216
src/protocols/ssh/ssh_key.c
View File

@ -1,216 +0,0 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config.h"
#include "ssh_buffer.h"
#include "ssh_key.h"
#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/dsa.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/obj_mac.h>
#include <openssl/pem.h>
#include <openssl/rsa.h>
#include <stdlib.h>
#include <string.h>
ssh_key* ssh_key_alloc(char* data, int length, char* passphrase) {
ssh_key* key;
BIO* key_bio;
char* public_key;
char* pos;
/* Create BIO for reading key from memory */
key_bio = BIO_new_mem_buf(data, length);
/* If RSA key, load RSA */
if (length > sizeof(SSH_RSA_KEY_HEADER)-1
&& memcmp(SSH_RSA_KEY_HEADER, data,
sizeof(SSH_RSA_KEY_HEADER)-1) == 0) {
RSA* rsa_key;
/* Read key */
rsa_key = PEM_read_bio_RSAPrivateKey(key_bio, NULL, NULL, passphrase);
if (rsa_key == NULL)
return NULL;
/* Allocate key */
key = malloc(sizeof(ssh_key));
key->rsa = rsa_key;
/* Set type */
key->type = SSH_KEY_RSA;
/* Allocate space for public key */
public_key = malloc(4096);
pos = public_key;
/* Derive public key */
buffer_write_string(&pos, "ssh-rsa", sizeof("ssh-rsa")-1);
buffer_write_bignum(&pos, rsa_key->e);
buffer_write_bignum(&pos, rsa_key->n);
/* Save public key to structure */
key->public_key = public_key;
key->public_key_length = pos - public_key;
}
/* If DSA key, load DSA */
else if (length > sizeof(SSH_DSA_KEY_HEADER)-1
&& memcmp(SSH_DSA_KEY_HEADER, data,
sizeof(SSH_DSA_KEY_HEADER)-1) == 0) {
DSA* dsa_key;
/* Read key */
dsa_key = PEM_read_bio_DSAPrivateKey(key_bio, NULL, NULL, passphrase);
if (dsa_key == NULL)
return NULL;
/* Allocate key */
key = malloc(sizeof(ssh_key));
key->dsa = dsa_key;
/* Set type */
key->type = SSH_KEY_DSA;
/* Allocate space for public key */
public_key = malloc(4096);
pos = public_key;
/* Derive public key */
buffer_write_string(&pos, "ssh-dss", sizeof("ssh-dss")-1);
buffer_write_bignum(&pos, dsa_key->p);
buffer_write_bignum(&pos, dsa_key->q);
buffer_write_bignum(&pos, dsa_key->g);
buffer_write_bignum(&pos, dsa_key->pub_key);
/* Save public key to structure */
key->public_key = public_key;
key->public_key_length = pos - public_key;
}
/* Otherwise, unsupported type */
else {
BIO_free(key_bio);
return NULL;
}
/* Copy private key to structure */
key->private_key_length = length;
key->private_key = malloc(length);
memcpy(key->private_key, data, length);
BIO_free(key_bio);
return key;
}
const char* ssh_key_error() {
/* Return static error string */
return ERR_reason_error_string(ERR_get_error());
}
void ssh_key_free(ssh_key* key) {
/* Free key-specific data */
if (key->type == SSH_KEY_RSA)
RSA_free(key->rsa);
else if (key->type == SSH_KEY_DSA)
DSA_free(key->dsa);
free(key->public_key);
free(key);
}
int ssh_key_sign(ssh_key* key, const char* data, int length, unsigned char* sig) {
const EVP_MD* md;
EVP_MD_CTX md_ctx;
unsigned char digest[EVP_MAX_MD_SIZE];
unsigned int dlen, len;
/* Get SHA1 digest */
if ((md = EVP_get_digestbynid(NID_sha1)) == NULL)
return -1;
/* Digest data */
EVP_DigestInit(&md_ctx, md);
EVP_DigestUpdate(&md_ctx, data, length);
EVP_DigestFinal(&md_ctx, digest, &dlen);
/* Sign with key */
switch (key->type) {
case SSH_KEY_RSA:
if (RSA_sign(NID_sha1, digest, dlen, sig, &len, key->rsa) == 1)
return len;
case SSH_KEY_DSA: {
DSA_SIG* dsa_sig = DSA_do_sign(digest, dlen, key->dsa);
if (dsa_sig != NULL) {
/* Compute size of each half of signature */
int rlen = BN_num_bytes(dsa_sig->r);
int slen = BN_num_bytes(dsa_sig->s);
/* Ensure each number is within the required size */
if (rlen > DSA_SIG_NUMBER_SIZE || slen > DSA_SIG_NUMBER_SIZE)
return -1;
/* Init to all zeroes */
memset(sig, 0, DSA_SIG_SIZE);
/* Add R at the end of the first block of the signature */
BN_bn2bin(dsa_sig->r, sig + DSA_SIG_SIZE
- DSA_SIG_NUMBER_SIZE - rlen);
/* Add S at the end of the second block of the signature */
BN_bn2bin(dsa_sig->s, sig + DSA_SIG_SIZE - slen);
/* Done */
DSA_SIG_free(dsa_sig);
return DSA_SIG_SIZE;
}
}
}
return -1;
}

137
src/protocols/ssh/ssh_key.h
View File

@ -1,137 +0,0 @@
/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef _GUAC_SSH_KEY_H
#define _GUAC_SSH_KEY_H
#include "config.h"
#include <openssl/ossl_typ.h>
/**
* The expected header of RSA private keys.
*/
#define SSH_RSA_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
/**
* The expected header of DSA private keys.
*/
#define SSH_DSA_KEY_HEADER "-----BEGIN DSA PRIVATE KEY-----"
/**
* The size of single number within a DSA signature, in bytes.
*/
#define DSA_SIG_NUMBER_SIZE 20
/**
* The size of a DSA signature, in bytes.
*/
#define DSA_SIG_SIZE DSA_SIG_NUMBER_SIZE*2
/**
* The type of an SSH key.
*/
typedef enum ssh_key_type {
/**
* RSA key.
*/
SSH_KEY_RSA,
/**
* DSA key.
*/
SSH_KEY_DSA
} ssh_key_type;
/**
* Abstraction of a key used for SSH authentication.
*/
typedef struct ssh_key {
/**
* The type of this key.
*/
ssh_key_type type;
/**
* Underlying RSA private key, if any.
*/
RSA* rsa;
/**
* Underlying DSA private key, if any.
*/
DSA* dsa;
/**
* The associated public key, encoded as necessary for SSH.
*/
char* public_key;
/**
* The length of the public key, in bytes.
*/
int public_key_length;
/**
* The private key, encoded as necessary for SSH.
*/
char* private_key;
/**
* The length of the private key, in bytes.
*/
int private_key_length;
} ssh_key;
/**
* Allocates a new key containing the given private key data and specified
* passphrase. If unable to read the key, NULL is returned.
*/
ssh_key* ssh_key_alloc(char* data, int length, char* passphrase);
/**
* Returns a statically-allocated string describing the most recent SSH key
* error.
*
* @return
* A statically-allocated string describing the most recent SSH key error.
*/
const char* ssh_key_error();
/**
* Frees all memory associated with the given key.
*/
void ssh_key_free(ssh_key* key);
/**
* Signs the given data using the given key, returning the length of the
* signature in bytes, or a value less than zero on error.
*/
int ssh_key_sign(ssh_key* key, const char* data, int length, unsigned char* sig);
#endif