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Diffstat (limited to 'crypto/openssh/auth-rsa.c')
-rw-r--r--crypto/openssh/auth-rsa.c478
1 files changed, 0 insertions, 478 deletions
diff --git a/crypto/openssh/auth-rsa.c b/crypto/openssh/auth-rsa.c
deleted file mode 100644
index d385ab739ee9c..0000000000000
--- a/crypto/openssh/auth-rsa.c
+++ /dev/null
@@ -1,478 +0,0 @@
-/*
- *
- * 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.
- *
- * $FreeBSD$
- */
-
-#include "includes.h"
-RCSID("$Id: auth-rsa.c,v 1.18 2000/02/11 10:59:11 markus Exp $");
-
-#include "rsa.h"
-#include "packet.h"
-#include "xmalloc.h"
-#include "ssh.h"
-#include "mpaux.h"
-#include "uidswap.h"
-#include "servconf.h"
-
-#include <openssl/rsa.h>
-#include <openssl/md5.h>
-
-/* 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;
- RSA *pk;
- BN_CTX *ctx;
- unsigned char buf[32], mdbuf[16], response[16];
- MD5_CTX md;
- unsigned int i;
- int plen, len;
-
- encrypted_challenge = BN_new();
- challenge = BN_new();
-
- /* Generate a random challenge. */
- BN_rand(challenge, 256, 0, 0);
- ctx = BN_CTX_new();
- BN_mod(challenge, challenge, n, ctx);
- BN_CTX_free(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();
- BN_clear_free(encrypted_challenge);
- packet_write_wait();
-
- /* 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();
-
- /* 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);
- BN_clear_free(challenge);
-
- /* 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 == '"')
- quoted = !quoted;
- }
- } else
- options = NULL;
-
- /* Parse the key from the line. */
- if (!auth_rsa_read_key(&cp, &bits, e, n)) {
- debug("%.100s, line %lu: bad key syntax",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: bad key syntax",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- /* cp now points to the comment part. */
-
- /* Check if the we have found the desired key (identified by its modulus). */
- if (BN_cmp(n, client_n) != 0)
- continue;
-
- /* check the real bits */
- if (bits != BN_num_bits(n))
- log("Warning: %s, line %ld: keysize mismatch: "
- "actual %d vs. announced %d.",
- file, linenum, BN_num_bits(n), bits);
-
- /* We have found the desired key. */
-
- /* Perform the challenge-response dialog for this key. */
- if (!auth_rsa_challenge_dialog(e, n)) {
- /* Wrong response. */
- verbose("Wrong response to RSA authentication challenge.");
- packet_send_debug("Wrong response to RSA authentication challenge.");
- continue;
- }
- /*
- * Correct response. The client has been successfully
- * authenticated. Note that we have not yet processed the
- * options; this will be reset if the options cause the
- * authentication to be rejected.
- */
- authenticated = 1;
-
- /* RSA part of authentication was accepted. Now process the options. */
- if (options) {
- while (*options && *options != ' ' && *options != '\t') {
- cp = "no-port-forwarding";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("Port forwarding disabled.");
- no_port_forwarding_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "no-agent-forwarding";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("Agent forwarding disabled.");
- no_agent_forwarding_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "no-X11-forwarding";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("X11 forwarding disabled.");
- no_x11_forwarding_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "no-pty";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- packet_send_debug("Pty allocation disabled.");
- no_pty_flag = 1;
- options += strlen(cp);
- goto next_option;
- }
- cp = "command=\"";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- int i;
- options += strlen(cp);
- forced_command = xmalloc(strlen(options) + 1);
- i = 0;
- while (*options) {
- if (*options == '"')
- break;
- if (*options == '\\' && options[1] == '"') {
- options += 2;
- forced_command[i++] = '"';
- continue;
- }
- forced_command[i++] = *options++;
- }
- if (!*options) {
- debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- forced_command[i] = 0;
- packet_send_debug("Forced command: %.900s", forced_command);
- options++;
- goto next_option;
- }
- cp = "environment=\"";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- int i;
- char *s;
- struct envstring *new_envstring;
- options += strlen(cp);
- s = xmalloc(strlen(options) + 1);
- i = 0;
- while (*options) {
- if (*options == '"')
- break;
- if (*options == '\\' && options[1] == '"') {
- options += 2;
- s[i++] = '"';
- continue;
- }
- s[i++] = *options++;
- }
- if (!*options) {
- debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- s[i] = 0;
- packet_send_debug("Adding to environment: %.900s", s);
- debug("Adding to environment: %.900s", s);
- options++;
- new_envstring = xmalloc(sizeof(struct envstring));
- new_envstring->s = s;
- new_envstring->next = custom_environment;
- custom_environment = new_envstring;
- goto next_option;
- }
- cp = "from=\"";
- if (strncmp(options, cp, strlen(cp)) == 0) {
- char *patterns = xmalloc(strlen(options) + 1);
- int i;
- options += strlen(cp);
- i = 0;
- while (*options) {
- if (*options == '"')
- break;
- if (*options == '\\' && options[1] == '"') {
- options += 2;
- patterns[i++] = '"';
- continue;
- }
- patterns[i++] = *options++;
- }
- if (!*options) {
- debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- packet_send_debug("%.100s, line %lu: missing end quote",
- SSH_USER_PERMITTED_KEYS, linenum);
- continue;
- }
- patterns[i] = 0;
- options++;
- if (!match_hostname(get_canonical_hostname(), patterns,
- strlen(patterns)) &&
- !match_hostname(get_remote_ipaddr(), patterns,
- strlen(patterns))) {
- log("RSA authentication tried for %.100s with correct key but not from a permitted host (host=%.200s, ip=%.200s).",
- pw->pw_name, get_canonical_hostname(),
- get_remote_ipaddr());
- packet_send_debug("Your host '%.200s' is not permitted to use this key for login.",
- get_canonical_hostname());
- xfree(patterns);
- /* key invalid for this host, reset flags */
- authenticated = 0;
- no_agent_forwarding_flag = 0;
- no_port_forwarding_flag = 0;
- no_pty_flag = 0;
- no_x11_forwarding_flag = 0;
- while (custom_environment) {
- struct envstring *ce = custom_environment;
- custom_environment = ce->next;
- xfree(ce->s);
- xfree(ce);
- }
- if (forced_command) {
- xfree(forced_command);
- forced_command = NULL;
- }
- break;
- }
- xfree(patterns);
- /* Host name matches. */
- goto next_option;
- }
- bad_option:
- log("Bad options in %.100s file, line %lu: %.50s",
- SSH_USER_PERMITTED_KEYS, linenum, options);
- packet_send_debug("Bad options in %.100s file, line %lu: %.50s",
- SSH_USER_PERMITTED_KEYS, linenum, options);
- authenticated = 0;
- break;
-
- next_option:
- /*
- * Skip the comma, and move to the next option
- * (or break out if there are no more).
- */
- if (!*options)
- fatal("Bugs in auth-rsa.c option processing.");
- if (*options == ' ' || *options == '\t')
- break; /* End of options. */
- if (*options != ',')
- goto bad_option;
- options++;
- /* Process the next option. */
- continue;
- }
- }
- /*
- * Break out of the loop if authentication was successful;
- * otherwise continue searching.
- */
- if (authenticated)
- break;
- }
-
- /* Restore the privileged uid. */
- restore_uid();
-
- /* Close the file. */
- fclose(f);
-
- BN_clear_free(n);
- BN_clear_free(e);
-
- if (authenticated)
- packet_send_debug("RSA authentication accepted.");
-
- /* Return authentication result. */
- return authenticated;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-24 05:48:35 +0000