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mutt_ssl.c
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/**
* @file
* Handling of OpenSSL encryption
*
* @authors
* Copyright (C) 1999-2001 Tommi Komulainen <[email protected]>
*
* @copyright
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation, either version 2 of the License, or (at your option) any later
* version.
*
* This program 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 General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <errno.h>
#include <limits.h>
#include <openssl/asn1.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/obj_mac.h>
#include <openssl/ossl_typ.h>
#include <openssl/pem.h>
#include <openssl/rand.h>
#include <openssl/ssl.h>
#include <openssl/ssl3.h>
#include <openssl/x509.h>
#include <openssl/x509_vfy.h>
#include <openssl/x509v3.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "mutt.h"
#include "mutt_ssl.h"
#include "account.h"
#include "globals.h"
#include "keymap.h"
#include "lib/lib.h"
#include "mutt_idna.h"
#include "mutt_menu.h"
#include "mutt_socket.h"
#include "opcodes.h"
#include "options.h"
#include "protos.h"
/* Just in case OpenSSL doesn't define DEVRANDOM */
#ifndef DEVRANDOM
#define DEVRANDOM "/dev/urandom"
#endif
/* This is ugly, but as RAND_status came in on OpenSSL version 0.9.5
* and the code has to support older versions too, this is seemed to
* be cleaner way compared to having even uglier #ifdefs all around.
*/
#ifdef HAVE_RAND_STATUS
#define HAVE_ENTROPY() (RAND_status() == 1)
#else
static int entropy_byte_count = 0;
/* OpenSSL fills the entropy pool from /dev/urandom if it exists */
#define HAVE_ENTROPY() (!access(DEVRANDOM, R_OK) || entropy_byte_count >= 16)
#endif
/* index for storing hostname as application specific data in SSL structure */
static int HostExDataIndex = -1;
/* Index for storing the "skip mode" state in SSL structure. When the
* user skips a certificate in the chain, the stored value will be
* non-null. */
static int SkipModeExDataIndex = -1;
/* keep a handle on accepted certificates in case we want to
* open up another connection to the same server in this session */
static STACK_OF(X509) *SslSessionCerts = NULL;
/**
* struct SslSockData - SSL socket data
*/
struct SslSockData
{
SSL_CTX *ctx;
SSL *ssl;
X509 *cert;
unsigned char isopen;
};
/**
* ssl_load_certificates - Load certificates and filter out the expired ones
*
* ssl certificate verification can behave strangely if there are expired certs
* loaded into the trusted store. This function filters out expired certs.
*
* Previously the code used this form:
* SSL_CTX_load_verify_locations (ssldata->ctx, SslCertFile, NULL);
*/
static int ssl_load_certificates(SSL_CTX *ctx)
{
FILE *fp = NULL;
X509 *cert = NULL;
X509_STORE *store = NULL;
int rv = 1;
#ifdef DEBUG
char buf[STRING];
#endif
mutt_debug(2, "ssl_load_certificates: loading trusted certificates\n");
store = SSL_CTX_get_cert_store(ctx);
if (!store)
{
store = X509_STORE_new();
SSL_CTX_set_cert_store(ctx, store);
}
if ((fp = fopen(SslCertFile, "rt")) == NULL)
return 0;
while (NULL != PEM_read_X509(fp, &cert, NULL, NULL))
{
if ((X509_cmp_current_time(X509_get_notBefore(cert)) >= 0) ||
(X509_cmp_current_time(X509_get_notAfter(cert)) <= 0))
{
mutt_debug(2, "ssl_load_certificates: filtering expired cert: %s\n",
X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf)));
}
else
{
X509_STORE_add_cert(store, cert);
}
}
/* PEM_read_X509 sets the error NO_START_LINE on eof */
if (ERR_GET_REASON(ERR_peek_last_error()) != PEM_R_NO_START_LINE)
rv = 0;
ERR_clear_error();
X509_free(cert);
safe_fclose(&fp);
return rv;
}
static int ssl_set_verify_partial(SSL_CTX *ctx)
{
int rv = 0;
#ifdef HAVE_SSL_PARTIAL_CHAIN
X509_VERIFY_PARAM *param = NULL;
if (option(OPT_SSL_VERIFY_PARTIAL))
{
param = X509_VERIFY_PARAM_new();
if (param)
{
X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_PARTIAL_CHAIN);
if (0 == SSL_CTX_set1_param(ctx, param))
{
mutt_debug(2, "ssl_set_verify_partial: SSL_CTX_set1_param() failed.\n");
rv = -1;
}
X509_VERIFY_PARAM_free(param);
}
else
{
mutt_debug(2,
"ssl_set_verify_partial: X509_VERIFY_PARAM_new() failed.\n");
rv = -1;
}
}
#endif
return rv;
}
static int add_entropy(const char *file)
{
struct stat st;
int n = -1;
if (!file)
return 0;
if (stat(file, &st) == -1)
return errno == ENOENT ? 0 : -1;
mutt_message(_("Filling entropy pool: %s...\n"), file);
/* check that the file permissions are secure */
if (st.st_uid != getuid() || ((st.st_mode & (S_IWGRP | S_IRGRP)) != 0) ||
((st.st_mode & (S_IWOTH | S_IROTH)) != 0))
{
mutt_error(_("%s has insecure permissions!"), file);
mutt_sleep(2);
return -1;
}
#ifdef HAVE_RAND_EGD
n = RAND_egd(file);
#endif
if (n <= 0)
n = RAND_load_file(file, -1);
#ifndef HAVE_RAND_STATUS
if (n > 0)
entropy_byte_count += n;
#endif
return n;
}
static void ssl_err(struct SslSockData *data, int err)
{
int e = SSL_get_error(data->ssl, err);
switch (e)
{
case SSL_ERROR_NONE:
return;
case SSL_ERROR_ZERO_RETURN:
data->isopen = 0;
break;
case SSL_ERROR_SYSCALL:
data->isopen = 0;
break;
}
#ifdef DEBUG
const char *errmsg = NULL;
unsigned long sslerr;
switch (e)
{
case SSL_ERROR_ZERO_RETURN:
errmsg = "SSL connection closed";
break;
case SSL_ERROR_WANT_READ:
errmsg = "retry read";
break;
case SSL_ERROR_WANT_WRITE:
errmsg = "retry write";
break;
case SSL_ERROR_WANT_CONNECT:
errmsg = "retry connect";
break;
case SSL_ERROR_WANT_ACCEPT:
errmsg = "retry accept";
break;
case SSL_ERROR_WANT_X509_LOOKUP:
errmsg = "retry x509 lookup";
break;
case SSL_ERROR_SYSCALL:
errmsg = "I/O error";
break;
case SSL_ERROR_SSL:
sslerr = ERR_get_error();
switch (sslerr)
{
case 0:
switch (err)
{
case 0:
errmsg = "EOF";
break;
default:
errmsg = strerror(errno);
}
break;
default:
errmsg = ERR_error_string(sslerr, NULL);
}
break;
default:
errmsg = "unknown error";
}
mutt_debug(1, "SSL error: %s\n", errmsg);
#endif
}
static void ssl_dprint_err_stack(void)
{
#ifdef DEBUG
BIO *bio = NULL;
char *buf = NULL;
long buflen;
char *output = NULL;
if (!(bio = BIO_new(BIO_s_mem())))
return;
ERR_print_errors(bio);
if ((buflen = BIO_get_mem_data(bio, &buf)) > 0)
{
output = safe_malloc(buflen + 1);
memcpy(output, buf, buflen);
output[buflen] = '\0';
mutt_debug(1, "SSL error stack: %s\n", output);
FREE(&output);
}
BIO_free(bio);
#endif
}
static int ssl_passwd_cb(char *buf, int size, int rwflag, void *userdata)
{
struct Account *account = (struct Account *) userdata;
if (mutt_account_getuser(account))
return 0;
mutt_debug(2, "ssl_passwd_cb: getting password for %s@%s:%u\n", account->user,
account->host, account->port);
if (mutt_account_getpass(account))
return 0;
return snprintf(buf, size, "%s", account->pass);
}
static int ssl_socket_open_err(struct Connection *conn)
{
mutt_error(_("SSL disabled due to the lack of entropy"));
mutt_sleep(2);
return -1;
}
static int ssl_socket_close(struct Connection *conn)
{
struct SslSockData *data = conn->sockdata;
if (data)
{
if (data->isopen)
SSL_shutdown(data->ssl);
/* hold onto this for the life of mutt, in case we want to reconnect.
* The purist in me wants a mutt_exit hook. */
SSL_free(data->ssl);
SSL_CTX_free(data->ctx);
FREE(&conn->sockdata);
}
return raw_socket_close(conn);
}
static char *x509_get_part(X509_NAME *name, int nid)
{
static char ret[SHORT_STRING];
if (!name || X509_NAME_get_text_by_NID(name, nid, ret, sizeof(ret)) < 0)
strfcpy(ret, _("Unknown"), sizeof(ret));
return ret;
}
static void x509_fingerprint(char *s, int l, X509 *cert, const EVP_MD *(*hashfunc)(void) )
{
unsigned char md[EVP_MAX_MD_SIZE];
unsigned int n;
int j;
if (!X509_digest(cert, hashfunc(), md, &n))
{
snprintf(s, l, "%s", _("[unable to calculate]"));
}
else
{
for (j = 0; j < (int) n; j++)
{
char ch[8];
snprintf(ch, 8, "%02X%s", md[j], (j % 2 ? " " : ""));
safe_strcat(s, l, ch);
}
}
}
static char *asn1time_to_string(ASN1_UTCTIME *tm)
{
static char buf[64];
BIO *bio = NULL;
strfcpy(buf, _("[invalid date]"), sizeof(buf));
bio = BIO_new(BIO_s_mem());
if (bio)
{
if (ASN1_TIME_print(bio, tm))
(void) BIO_read(bio, buf, sizeof(buf));
BIO_free(bio);
}
return buf;
}
static bool compare_certificates(X509 *cert, X509 *peercert,
unsigned char *peermd, unsigned int peermdlen)
{
unsigned char md[EVP_MAX_MD_SIZE];
unsigned int mdlen;
/* Avoid CPU-intensive digest calculation if the certificates are
* not even remotely equal.
*/
if (X509_subject_name_cmp(cert, peercert) != 0 || X509_issuer_name_cmp(cert, peercert) != 0)
return false;
if (!X509_digest(cert, EVP_sha256(), md, &mdlen) || peermdlen != mdlen)
return false;
if (memcmp(peermd, md, mdlen) != 0)
return false;
return true;
}
static bool check_certificate_expiration(X509 *peercert, bool silent)
{
if (option(OPT_SSL_VERIFY_DATES) != MUTT_NO)
{
if (X509_cmp_current_time(X509_get_notBefore(peercert)) >= 0)
{
if (!silent)
{
mutt_debug(2, "Server certificate is not yet valid\n");
mutt_error(_("Server certificate is not yet valid"));
mutt_sleep(2);
}
return false;
}
if (X509_cmp_current_time(X509_get_notAfter(peercert)) <= 0)
{
if (!silent)
{
mutt_debug(2, "Server certificate has expired\n");
mutt_error(_("Server certificate has expired"));
mutt_sleep(2);
}
return false;
}
}
return true;
}
/**
* hostname_match - Does the hostname match the certificate
*/
static bool hostname_match(const char *hostname, const char *certname)
{
const char *cmp1 = NULL, *cmp2 = NULL;
if (strncmp(certname, "*.", 2) == 0)
{
cmp1 = certname + 2;
cmp2 = strchr(hostname, '.');
if (!cmp2)
{
return false;
}
else
{
cmp2++;
}
}
else
{
cmp1 = certname;
cmp2 = hostname;
}
if (*cmp1 == '\0' || *cmp2 == '\0')
{
return false;
}
if (strcasecmp(cmp1, cmp2) != 0)
{
return false;
}
return true;
}
/**
* ssl_init - Initialist the SSL library
*
* OpenSSL library needs to be fed with sufficient entropy. On systems with
* /dev/urandom, this is done transparently by the library itself, on other
* systems we need to fill the entropy pool ourselves.
*
* Even though only OpenSSL 0.9.5 and later will complain about the lack of
* entropy, we try to our best and fill the pool with older versions also.
* (That's the reason for the ugly ifdefs and macros, otherwise I could have
* simply ifdef'd the whole ssl_init funcion)
*/
static int ssl_init(void)
{
char path[_POSIX_PATH_MAX];
static bool init_complete = false;
if (init_complete)
return 0;
if (!HAVE_ENTROPY())
{
/* load entropy from files */
add_entropy(SslEntropyFile);
add_entropy(RAND_file_name(path, sizeof(path)));
/* load entropy from egd sockets */
#ifdef HAVE_RAND_EGD
add_entropy(getenv("EGDSOCKET"));
snprintf(path, sizeof(path), "%s/.entropy", NONULL(HomeDir));
add_entropy(path);
add_entropy("/tmp/entropy");
#endif
/* shuffle $RANDFILE (or ~/.rnd if unset) */
RAND_write_file(RAND_file_name(path, sizeof(path)));
mutt_clear_error();
if (!HAVE_ENTROPY())
{
mutt_error(_("Failed to find enough entropy on your system"));
mutt_sleep(2);
return -1;
}
}
/* I don't think you can do this just before reading the error. The call
* itself might clobber the last SSL error. */
SSL_load_error_strings();
SSL_library_init();
init_complete = true;
return 0;
}
static int ssl_socket_read(struct Connection *conn, char *buf, size_t len)
{
struct SslSockData *data = conn->sockdata;
int rc;
rc = SSL_read(data->ssl, buf, len);
if (rc <= 0 || errno == EINTR)
{
if (errno == EINTR)
{
rc = -1;
}
data->isopen = 0;
ssl_err(data, rc);
}
return rc;
}
static int ssl_socket_write(struct Connection *conn, const char *buf, size_t len)
{
struct SslSockData *data = conn->sockdata;
int rc;
rc = SSL_write(data->ssl, buf, len);
if (rc <= 0 || errno == EINTR)
{
if (errno == EINTR)
{
rc = -1;
}
ssl_err(data, rc);
}
return rc;
}
static void ssl_get_client_cert(struct SslSockData *ssldata, struct Connection *conn)
{
if (SslClientCert)
{
mutt_debug(2, "Using client certificate %s\n", SslClientCert);
SSL_CTX_set_default_passwd_cb_userdata(ssldata->ctx, &conn->account);
SSL_CTX_set_default_passwd_cb(ssldata->ctx, ssl_passwd_cb);
SSL_CTX_use_certificate_file(ssldata->ctx, SslClientCert, SSL_FILETYPE_PEM);
SSL_CTX_use_PrivateKey_file(ssldata->ctx, SslClientCert, SSL_FILETYPE_PEM);
/* if we are using a client cert, SASL may expect an external auth name */
mutt_account_getuser(&conn->account);
}
}
static int tls_close(struct Connection *conn)
{
int rc;
rc = ssl_socket_close(conn);
conn->conn_read = raw_socket_read;
conn->conn_write = raw_socket_write;
conn->conn_close = raw_socket_close;
return rc;
}
static bool check_certificate_cache(X509 *peercert)
{
unsigned char peermd[EVP_MAX_MD_SIZE];
unsigned int peermdlen;
X509 *cert = NULL;
int i;
if (!X509_digest(peercert, EVP_sha256(), peermd, &peermdlen) || !SslSessionCerts)
{
return false;
}
for (i = sk_X509_num(SslSessionCerts); i-- > 0;)
{
cert = sk_X509_value(SslSessionCerts, i);
if (compare_certificates(cert, peercert, peermd, peermdlen))
{
return true;
}
}
return false;
}
static int check_certificate_file(X509 *peercert)
{
unsigned char peermd[EVP_MAX_MD_SIZE];
unsigned int peermdlen;
X509 *cert = NULL;
int pass = 0;
FILE *fp = NULL;
if (!SslCertFile)
return 0;
if ((fp = fopen(SslCertFile, "rt")) == NULL)
return 0;
if (!X509_digest(peercert, EVP_sha256(), peermd, &peermdlen))
{
safe_fclose(&fp);
return 0;
}
while (PEM_read_X509(fp, &cert, NULL, NULL) != NULL)
{
if (compare_certificates(cert, peercert, peermd, peermdlen) &&
check_certificate_expiration(cert, true))
{
pass = 1;
break;
}
}
/* PEM_read_X509 sets an error on eof */
if (!pass)
ERR_clear_error();
X509_free(cert);
safe_fclose(&fp);
return pass;
}
/**
* check_host - Check the host on the certificate
*/
static int check_host(X509 *x509cert, const char *hostname, char *err, size_t errlen)
{
int i, rc = 0;
/* hostname in ASCII format: */
char *hostname_ascii = NULL;
/* needed to get the common name: */
X509_NAME *x509_subject = NULL;
char *buf = NULL;
int bufsize;
/* needed to get the DNS subjectAltNames: */
STACK_OF(GENERAL_NAME) * subj_alt_names;
int subj_alt_names_count;
GENERAL_NAME *subj_alt_name = NULL;
/* did we find a name matching hostname? */
bool match_found;
/* Check if 'hostname' matches the one of the subjectAltName extensions of
* type DNS or the Common Name (CN). */
#ifdef HAVE_LIBIDN
if (idna_to_ascii_lz(hostname, &hostname_ascii, 0) != IDNA_SUCCESS)
{
hostname_ascii = safe_strdup(hostname);
}
#else
hostname_ascii = safe_strdup(hostname);
#endif
/* Try the DNS subjectAltNames. */
match_found = false;
if ((subj_alt_names = X509_get_ext_d2i(x509cert, NID_subject_alt_name, NULL, NULL)))
{
subj_alt_names_count = sk_GENERAL_NAME_num(subj_alt_names);
for (i = 0; i < subj_alt_names_count; i++)
{
subj_alt_name = sk_GENERAL_NAME_value(subj_alt_names, i);
if (subj_alt_name->type == GEN_DNS)
{
if (subj_alt_name->d.ia5->length >= 0 &&
mutt_strlen((char *) subj_alt_name->d.ia5->data) ==
(size_t) subj_alt_name->d.ia5->length &&
(match_found = hostname_match(hostname_ascii,
(char *) (subj_alt_name->d.ia5->data))))
{
break;
}
}
}
GENERAL_NAMES_free(subj_alt_names);
}
if (!match_found)
{
/* Try the common name */
if (!(x509_subject = X509_get_subject_name(x509cert)))
{
if (err && errlen)
strfcpy(err, _("cannot get certificate subject"), errlen);
goto out;
}
/* first get the space requirements */
bufsize = X509_NAME_get_text_by_NID(x509_subject, NID_commonName, NULL, 0);
if (bufsize == -1)
{
if (err && errlen)
strfcpy(err, _("cannot get certificate common name"), errlen);
goto out;
}
bufsize++; /* space for the terminal nul char */
buf = safe_malloc((size_t) bufsize);
if (X509_NAME_get_text_by_NID(x509_subject, NID_commonName, buf, bufsize) == -1)
{
if (err && errlen)
strfcpy(err, _("cannot get certificate common name"), errlen);
goto out;
}
/* cast is safe since bufsize is incremented above, so bufsize-1 is always
* zero or greater.
*/
if (mutt_strlen(buf) == (size_t) bufsize - 1)
{
match_found = hostname_match(hostname_ascii, buf);
}
}
if (!match_found)
{
if (err && errlen)
snprintf(err, errlen, _("certificate owner does not match hostname %s"), hostname);
goto out;
}
rc = 1;
out:
FREE(&buf);
FREE(&hostname_ascii);
return rc;
}
static int check_certificate_by_digest(X509 *peercert)
{
return check_certificate_expiration(peercert, false) && check_certificate_file(peercert);
}
static int ssl_cache_trusted_cert(X509 *c)
{
mutt_debug(1, "ssl_cache_trusted_cert: trusted\n");
if (!SslSessionCerts)
SslSessionCerts = sk_X509_new_null();
return (sk_X509_push(SslSessionCerts, X509_dup(c)));
}
static int interactive_check_cert(X509 *cert, int idx, int len, SSL *ssl, int allow_always)
{
static const int part[] = {
NID_commonName, /* CN */
NID_pkcs9_emailAddress, /* Email */
NID_organizationName, /* O */
NID_organizationalUnitName, /* OU */
NID_localityName, /* L */
NID_stateOrProvinceName, /* ST */
NID_countryName, /* C */
};
X509_NAME *x509_subject = NULL;
X509_NAME *x509_issuer = NULL;
char helpstr[LONG_STRING];
char buf[STRING];
char title[STRING];
struct Menu *menu = mutt_new_menu(MENU_GENERIC);
int done, row;
unsigned u;
FILE *fp = NULL;
int allow_skip = 0;
mutt_push_current_menu(menu);
menu->max = mutt_array_size(part) * 2 + 10;
menu->dialog = safe_calloc(1, menu->max * sizeof(char *));
for (int i = 0; i < menu->max; i++)
menu->dialog[i] = safe_calloc(1, SHORT_STRING * sizeof(char));
row = 0;
strfcpy(menu->dialog[row], _("This certificate belongs to:"), SHORT_STRING);
row++;
x509_subject = X509_get_subject_name(cert);
for (u = 0; u < mutt_array_size(part); u++)
snprintf(menu->dialog[row++], SHORT_STRING, " %s",
x509_get_part(x509_subject, part[u]));
row++;
strfcpy(menu->dialog[row], _("This certificate was issued by:"), SHORT_STRING);
row++;
x509_issuer = X509_get_issuer_name(cert);
for (u = 0; u < mutt_array_size(part); u++)
snprintf(menu->dialog[row++], SHORT_STRING, " %s",
x509_get_part(x509_issuer, part[u]));
row++;
snprintf(menu->dialog[row++], SHORT_STRING, "%s",
_("This certificate is valid"));
snprintf(menu->dialog[row++], SHORT_STRING, _(" from %s"),
asn1time_to_string(X509_get_notBefore(cert)));
snprintf(menu->dialog[row++], SHORT_STRING, _(" to %s"),
asn1time_to_string(X509_get_notAfter(cert)));
row++;
buf[0] = '\0';
x509_fingerprint(buf, sizeof(buf), cert, EVP_sha1);
snprintf(menu->dialog[row++], SHORT_STRING, _("SHA1 Fingerprint: %s"), buf);
buf[0] = '\0';
x509_fingerprint(buf, sizeof(buf), cert, EVP_md5);
snprintf(menu->dialog[row++], SHORT_STRING, _("MD5 Fingerprint: %s"), buf);
snprintf(title, sizeof(title),
_("SSL Certificate check (certificate %d of %d in chain)"), len - idx, len);
menu->title = title;
/* The leaf/host certificate can't be skipped. */
#ifdef HAVE_SSL_PARTIAL_CHAIN
if ((idx != 0) && (option(OPT_SSL_VERIFY_PARTIAL)))
allow_skip = 1;
#endif
/* Inside ssl_verify_callback(), this function is guarded by a call to
* check_certificate_by_digest(). This means if check_certificate_expiration() is
* true, then check_certificate_file() must be false. Therefore we don't need
* to also scan the certificate file here.
*/
allow_always = allow_always && SslCertFile && check_certificate_expiration(cert, true);
/* L10N:
* These four letters correspond to the choices in the next four strings:
* (r)eject, accept (o)nce, (a)ccept always, (s)kip.
* These prompts are the interactive certificate confirmation prompts for
* an OpenSSL connection.
*/
menu->keys = _("roas");
if (allow_always)
{
if (allow_skip)
menu->prompt = _("(r)eject, accept (o)nce, (a)ccept always, (s)kip");
else
menu->prompt = _("(r)eject, accept (o)nce, (a)ccept always");
}
else
{
if (allow_skip)
menu->prompt = _("(r)eject, accept (o)nce, (s)kip");
else
menu->prompt = _("(r)eject, accept (o)nce");
}
helpstr[0] = '\0';
mutt_make_help(buf, sizeof(buf), _("Exit "), MENU_GENERIC, OP_EXIT);
safe_strcat(helpstr, sizeof(helpstr), buf);
mutt_make_help(buf, sizeof(buf), _("Help"), MENU_GENERIC, OP_HELP);
safe_strcat(helpstr, sizeof(helpstr), buf);
menu->help = helpstr;
done = 0;
set_option(OPT_IGNORE_MACRO_EVENTS);
while (!done)
{
switch (mutt_menu_loop(menu))
{
case -1: /* abort */
case OP_MAX + 1: /* reject */
case OP_EXIT:
done = 1;
break;
case OP_MAX + 3: /* accept always */
if (!allow_always)
break;
done = 0;
if ((fp = fopen(SslCertFile, "a")))
{
if (PEM_write_X509(fp, cert))
done = 1;
safe_fclose(&fp);
}
if (!done)
{
mutt_error(_("Warning: Couldn't save certificate"));
mutt_sleep(2);
}
else
{
mutt_message(_("Certificate saved"));
mutt_sleep(0);
}
/* fall through */
case OP_MAX + 2: /* accept once */
done = 2;
SSL_set_ex_data(ssl, SkipModeExDataIndex, NULL);
ssl_cache_trusted_cert(cert);
break;
case OP_MAX + 4: /* skip */
if (!allow_skip)
break;
done = 2;
SSL_set_ex_data(ssl, SkipModeExDataIndex, &SkipModeExDataIndex);
break;
}
}
unset_option(OPT_IGNORE_MACRO_EVENTS);
mutt_pop_current_menu(menu);
mutt_menu_destroy(&menu);
mutt_debug(2, "ssl interactive_check_cert: done=%d\n", done);
return (done == 2);
}
/**
* ssl_verify_callback - certificate verification callback
*
* called for each certificate in the chain sent by the peer, starting from the
* root; returning 1 means that the given certificate is trusted, returning 0
* immediately aborts the SSL connection
*/
static int ssl_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
{
char buf[STRING];
const char *host = NULL;
int len, pos;
X509 *cert = NULL;
SSL *ssl = NULL;
int skip_mode;
#ifdef HAVE_SSL_PARTIAL_CHAIN
static int last_pos = 0;
static X509 *last_cert = NULL;
unsigned char last_cert_md[EVP_MAX_MD_SIZE];
unsigned int last_cert_mdlen;
#endif
if (!(ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx())))
{
mutt_debug(1, "ssl_verify_callback: failed to retrieve SSL structure from "
"X509_STORE_CTX\n");
return 0;
}
if (!(host = SSL_get_ex_data(ssl, HostExDataIndex)))
{
mutt_debug(1, "ssl_verify_callback: failed to retrieve hostname from SSL "
"structure\n");
return 0;
}
/* This is true when a previous entry in the certificate chain did
* not verify and the user manually chose to skip it via the
* $ssl_verify_partial_chains option.
* In this case, all following certificates need to be treated as non-verified
* until one is actually verified.
*/
skip_mode = (SSL_get_ex_data(ssl, SkipModeExDataIndex) != NULL);
cert = X509_STORE_CTX_get_current_cert(ctx);
pos = X509_STORE_CTX_get_error_depth(ctx);
len = sk_X509_num(X509_STORE_CTX_get_chain(ctx));
mutt_debug(1, "ssl_verify_callback: checking cert chain entry %s (preverify: "
"%d skipmode: %d)\n",
X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf)),
preverify_ok, skip_mode);
#ifdef HAVE_SSL_PARTIAL_CHAIN
/* Sometimes, when a certificate is (s)kipped, OpenSSL will pass it
* a second time with preverify_ok = 1. Don't show it or the user
* will think their "s" key is broken.
*/
if (option(OPT_SSL_VERIFY_PARTIAL))
{
if (skip_mode && preverify_ok && (pos == last_pos) && last_cert)