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path: root/block/sed-opal.c

Age	Commit message (Expand)	Author
2018-06-20	block: sed-opal: Fix a couple off by one bugs	Dan Carpenter
2018-04-05	Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block	Linus Torvalds
2018-03-16	block: sed-opal: fix u64 short atom length	Jonas Rabenstein
2018-03-06	block: sed-opal: fix response string extraction	Jonas Rabenstein
2018-02-22	treewide/trivial: Remove ';;$' typo noise	Ingo Molnar
2017-09-11	block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled	Scott Bauer
2017-04-07	block: sed-opal: Tone down all the pr_* to debugs	Scott Bauer
2017-03-30	block/sed-opal: fix spelling mistake: "Lifcycle" -> "Lifecycle"	Colin Ian King
2017-03-08	block/sed: Fix opal user range check and unused variables	Jon Derrick
2017-02-23	block/sed-opal: Propagate original error message to userland.	Scott Bauer
2017-02-23	block/sed-opal: Introduce free_opal_dev to free the structure and clean up state	Scott Bauer
2017-02-22	block/sed: Embed function data into the function sequence	Jon Derrick
2017-02-22	block/sed: Check received header lengths	Jon Derrick
2017-02-22	block/sed: Add helper to qualify response tokens	Jon Derrick
2017-02-22	block/sed: Use ssize_t on atom parsers to return errors	Jon Derrick
2017-02-17	block/sed-opal: allocate struct opal_dev dynamically	Christoph Hellwig
2017-02-17	block/sed-opal: tone down not supported warnings	Christoph Hellwig
2017-02-14	Move stack parameters for sed_ioctl to prevent oversized stack with CONFIG_KASAN	Scott Bauer
2017-02-06	block: Add Sed-opal library	Scott Bauer

generated by cgit v1.2.3 (git 2.25.1) at 2024-09-06 18:54:24 +0000

/*
 * 
 * auth-rsa.c
 * 
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * 
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * 
 * Created: Mon Mar 27 01:46:52 1995 ylo
 * 
 * RSA-based authentication.  This code determines whether to admit a login
 * based on RSA authentication.  This file also contains functions to check
 * validity of the host key.
 * 
 */

#include "includes.h"
RCSID("$Id: auth-rsa.c,v 1.12 2000/01/20 11:44:09 damien Exp $");

#include "rsa.h"
#include "packet.h"
#include "xmalloc.h"
#include "ssh.h"
#include "mpaux.h"
#include "uidswap.h"
#include "servconf.h"

#ifdef HAVE_OPENSSL
#include <openssl/rsa.h>
#include <openssl/md5.h>
#endif
#ifdef HAVE_SSL
#include <ssl/rsa.h>
#include <ssl/md5.h>
#endif

/* Flags that may be set in authorized_keys options. */
extern int no_port_forwarding_flag;
extern int no_agent_forwarding_flag;
extern int no_x11_forwarding_flag;
extern int no_pty_flag;
extern char *forced_command;
extern struct envstring *custom_environment;

/*
 * Session identifier that is used to bind key exchange and authentication
 * responses to a particular session.
 */
extern unsigned char session_id[16];

/*
 * The .ssh/authorized_keys file contains public keys, one per line, in the
 * following format:
 *   options bits e n comment
 * where bits, e and n are decimal numbers,
 * and comment is any string of characters up to newline.  The maximum
 * length of a line is 8000 characters.  See the documentation for a
 * description of the options.
 */

/*
 * Performs the RSA authentication challenge-response dialog with the client,
 * and returns true (non-zero) if the client gave the correct answer to
 * our challenge; returns zero if the client gives a wrong answer.
 */

int
auth_rsa_challenge_dialog(BIGNUM *e, BIGNUM *n)
{
	BIGNUM *challenge, *encrypted_challenge, *aux;
	RSA *pk;
	BN_CTX *ctx = BN_CTX_new();
	unsigned char buf[32], mdbuf[16], response[16];
	MD5_CTX md;
	unsigned int i;
	int plen, len;

	encrypted_challenge = BN_new();
	challenge = BN_new();
	aux = BN_new();

	/* Generate a random challenge. */
	BN_rand(challenge, 256, 0, 0);
	BN_mod(challenge, challenge, n, ctx);

	/* Create the public key data structure. */
	pk = RSA_new();
	pk->e = BN_new();
	BN_copy(pk->e, e);
	pk->n = BN_new();
	BN_copy(pk->n, n);

	/* Encrypt the challenge with the public key. */
	rsa_public_encrypt(encrypted_challenge, challenge, pk);
	RSA_free(pk);

	/* Send the encrypted challenge to the client. */
	packet_start(SSH_SMSG_AUTH_RSA_CHALLENGE);
	packet_put_bignum(encrypted_challenge);
	packet_send();
	packet_write_wait();

	/* The response is MD5 of decrypted challenge plus session id. */
	len = BN_num_bytes(challenge);
	if (len <= 0 || len > 32)
		fatal("auth_rsa_challenge_dialog: bad challenge length %d", len);
	memset(buf, 0, 32);
	BN_bn2bin(challenge, buf + 32 - len);
	MD5_Init(&md);
	MD5_Update(&md, buf, 32);
	MD5_Update(&md, session_id, 16);
	MD5_Final(mdbuf, &md);

	/* We will no longer need these. */
	BN_clear_free(encrypted_challenge);
	BN_clear_free(challenge);
	BN_clear_free(aux);
	BN_CTX_free(ctx);

	/* Wait for a response. */
	packet_read_expect(&plen, SSH_CMSG_AUTH_RSA_RESPONSE);
	packet_integrity_check(plen, 16, SSH_CMSG_AUTH_RSA_RESPONSE);
	for (i = 0; i < 16; i++)
		response[i] = packet_get_char();

	/* Verify that the response is the original challenge. */
	if (memcmp(response, mdbuf, 16) != 0) {
		/* Wrong answer. */
		return 0;
	}
	/* Correct answer. */
	return 1;
}

/*
 * Performs the RSA authentication dialog with the client.  This returns
 * 0 if the client could not be authenticated, and 1 if authentication was
 * successful.  This may exit if there is a serious protocol violation.
 */

int
auth_rsa(struct passwd *pw, BIGNUM *client_n)
{
	extern ServerOptions options;
	char line[8192], file[1024];
	int authenticated;
	unsigned int bits;
	FILE *f;
	unsigned long linenum = 0;
	struct stat st;
	BIGNUM *e, *n;

	/* Temporarily use the user's uid. */
	temporarily_use_uid(pw->pw_uid);

	/* The authorized keys. */
	snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir,
		 SSH_USER_PERMITTED_KEYS);

	/* Fail quietly if file does not exist */
	if (stat(file, &st) < 0) {
		/* Restore the privileged uid. */
		restore_uid();
		return 0;
	}
	/* Open the file containing the authorized keys. */
	f = fopen(file, "r");
	if (!f) {
		/* Restore the privileged uid. */
		restore_uid();
		packet_send_debug("Could not open %.900s for reading.", file);
		packet_send_debug("If your home is on an NFS volume, it may need to be world-readable.");
		return 0;
	}
	if (options.strict_modes) {
		int fail = 0;
		char buf[1024];
		/* Check open file in order to avoid open/stat races */
		if (fstat(fileno(f), &st) < 0 ||
		    (st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
		    (st.st_mode & 022) != 0) {
			snprintf(buf, sizeof buf, "RSA authentication refused for %.100s: "
				 "bad ownership or modes for '%s'.", pw->pw_name, file);
			fail = 1;
		} else {
			/* Check path to SSH_USER_PERMITTED_KEYS */
			int i;
			static const char *check[] = {
				"", SSH_USER_DIR, NULL
			};
			for (i = 0; check[i]; i++) {
				snprintf(line, sizeof line, "%.500s/%.100s", pw->pw_dir, check[i]);
				if (stat(line, &st) < 0 ||
				    (st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
				    (st.st_mode & 022) != 0) {
					snprintf(buf, sizeof buf, "RSA authentication refused for %.100s: "
						 "bad ownership or modes for '%s'.", pw->pw_name, line);
					fail = 1;
					break;
				}
			}
		}
		if (fail) {
			log(buf);
			packet_send_debug(buf);
			restore_uid();
			return 0;
		}
	}
	/* Flag indicating whether authentication has succeeded. */
	authenticated = 0;

	e = BN_new();
	n = BN_new();

	/*
	 * Go though the accepted keys, looking for the current key.  If
	 * found, perform a challenge-response dialog to verify that the
	 * user really has the corresponding private key.
	 */
	while (fgets(line, sizeof(line), f)) {
		char *cp;
		char *options;

		linenum++;

		/* Skip leading whitespace, empty and comment lines. */
		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
			;
		if (!*cp || *cp == '\n' || *cp == '#')
			continue;

		/*
		 * Check if there are options for this key, and if so,
		 * save their starting address and skip the option part
		 * for now.  If there are no options, set the starting
		 * address to NULL.
		 */
		if (*cp < '0' || *cp > '9') {
			int quoted = 0;
			options = cp;
			for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
				if (*cp == '\\' && cp[1] == '"')
					cp++;	/* Skip both */
				else if (*cp ==