*************************************************/
/* Copyright (c) University of Cambridge 1995 - 2019 */
-/* Copyright (c) The Exim Maintainers 2020 */
+/* Copyright (c) The Exim Maintainers 2020 - 2021 */
/* See the file NOTICE for conditions of use and distribution. */
/* Portions Copyright (c) The OpenSSL Project 1999 */
#if OPENSSL_VERSION_NUMBER >= 0x10100000L
# define EXIM_HAVE_OCSP_RESP_COUNT
# define OPENSSL_AUTO_SHA256
-# define EXIM_HAVE_ALPN
#else
# define EXIM_HAVE_EPHEM_RSA_KEX
# define EXIM_HAVE_RAND_PSEUDO
# ifndef DISABLE_OCSP
# define EXIM_HAVE_OCSP
# endif
+# define EXIM_HAVE_ALPN /* fail ret from hshake-cb is ignored by LibreSSL */
# else
# define EXIM_NEED_OPENSSL_INIT
# endif
# endif
#endif
+#if LIBRESSL_VERSION_NUMBER >= 0x3040000fL
+# define EXIM_HAVE_OPENSSL_CIPHER_GET_ID
+#endif
+
#if !defined(LIBRESSL_VERSION_NUMBER) \
|| LIBRESSL_VERSION_NUMBER >= 0x20010000L
# if !defined(OPENSSL_NO_ECDH)
{ US"no_tlsv1", SSL_OP_NO_TLSv1 },
#endif
#ifdef SSL_OP_NO_TLSv1_1
-#if SSL_OP_NO_TLSv1_1 == 0x00000400L
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+# if SSL_OP_NO_TLSv1_1 == 0x00000400L
/* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
-#warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
-#else
+# warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
+# define NO_SSL_OP_NO_TLSv1_1
+# endif
+# endif
+# ifndef NO_SSL_OP_NO_TLSv1_1
{ US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
-#endif
+# endif
#endif
#ifdef SSL_OP_NO_TLSv1_2
{ US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
builtin_macro_create(US"_HAVE_TLS_OCSP");
builtin_macro_create(US"_HAVE_TLS_OCSP_LIST");
# endif
+# ifdef EXIM_HAVE_ALPN
+builtin_macro_create(US"_HAVE_TLS_ALPN");
+# endif
}
#else
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
static SSL_CTX *server_sni = NULL;
#endif
+#ifdef EXIM_HAVE_ALPN
+static BOOL server_seen_alpn = FALSE;
+#endif
static char ssl_errstring[256];
*************************************************/
/* If dhparam is set, expand it, and load up the parameters for DH encryption.
+Server only.
Arguments:
sctx The current SSL CTX (inbound or outbound)
dhparam DH parameter file or fixed parameter identity string
- host connected host, if client; NULL if server
errstr error string pointer
Returns: TRUE if OK (nothing to set up, or setup worked)
*/
static BOOL
-init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host, uschar ** errstr)
+init_dh(SSL_CTX * sctx, uschar * dhparam, uschar ** errstr)
{
-BIO *bio;
-DH *dh;
-uschar *dhexpanded;
-const char *pem;
+BIO * bio;
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+DH * dh;
+#else
+EVP_PKEY * pkey;
+#endif
+uschar * dhexpanded;
+const char * pem;
int dh_bitsize;
if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr))
if (!(bio = BIO_new_file(CS dhexpanded, "r")))
{
tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
- host, US strerror(errno), errstr);
+ NULL, US strerror(errno), errstr);
return FALSE;
}
}
if (!(pem = std_dh_prime_named(dhexpanded)))
{
tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
- host, US strerror(errno), errstr);
+ NULL, US strerror(errno), errstr);
return FALSE;
}
bio = BIO_new_mem_buf(CS pem, -1);
}
-if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)))
+if (!(
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+ dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)
+#else
+ pkey = PEM_read_bio_Parameters_ex(bio, NULL, NULL, NULL)
+#endif
+ ) )
{
BIO_free(bio);
tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
- host, NULL, errstr);
+ NULL, NULL, errstr);
return FALSE;
}
/* note: our default limit of 2236 is not a multiple of 8; the limit comes from
- * an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with
- * 2236. But older OpenSSL can only report in bytes (octets), not bits.
- * If someone wants to dance at the edge, then they can raise the limit or use
- * current libraries. */
-#ifdef EXIM_HAVE_OPENSSL_DH_BITS
+an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with 2236.
+But older OpenSSL can only report in bytes (octets), not bits. If someone wants
+to dance at the edge, then they can raise the limit or use current libraries. */
+
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+# ifdef EXIM_HAVE_OPENSSL_DH_BITS
/* Added in commit 26c79d5641d; `git describe --contains` says OpenSSL_1_1_0-pre1~1022
- * This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */
+This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */
dh_bitsize = DH_bits(dh);
-#else
+# else
dh_bitsize = 8 * DH_size(dh);
+# endif
+#else /* 3.0.0 + */
+dh_bitsize = EVP_PKEY_get_bits(pkey);
#endif
-/* Even if it is larger, we silently return success rather than cause things
- * to fail out, so that a too-large DH will not knock out all TLS; it's a
- * debatable choice. */
-if (dh_bitsize > tls_dh_max_bits)
+/* Even if it is larger, we silently return success rather than cause things to
+fail out, so that a too-large DH will not knock out all TLS; it's a debatable
+choice. Likewise for a failing attempt to set one. */
+
+if (dh_bitsize <= tls_dh_max_bits)
{
- DEBUG(D_tls)
- debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d\n",
- dh_bitsize, tls_dh_max_bits);
+ if (
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+ SSL_CTX_set_tmp_dh(sctx, dh)
+#else
+ SSL_CTX_set0_tmp_dh_pkey(sctx, pkey)
+#endif
+ == 0)
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (D-H param setting '%s'): %s",
+ dhexpanded ? dhexpanded : US"default", ssl_errstring);
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+ /* EVP_PKEY_free(pkey); crashes */
+#endif
+ }
+ else
+ DEBUG(D_tls)
+ debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n",
+ dhexpanded ? dhexpanded : US"default", dh_bitsize);
}
else
- {
- SSL_CTX_set_tmp_dh(sctx, dh);
DEBUG(D_tls)
- debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n",
- dhexpanded ? dhexpanded : US"default", dh_bitsize);
- }
+ debug_printf("dhparams '%s' %d bits, is > tls_dh_max_bits limit of %d\n",
+ dhexpanded ? dhexpanded : US"default", dh_bitsize, tls_dh_max_bits);
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
DH_free(dh);
-BIO_free(bio);
+#endif
+/* The EVP_PKEY ownership stays with the ctx; do not free it */
+BIO_free(bio);
return TRUE;
}
* Initialize for ECDH *
*************************************************/
-/* Load parameters for ECDH encryption.
+/* Load parameters for ECDH encryption. Server only.
For now, we stick to NIST P-256 because: it's simple and easy to configure;
it avoids any patent issues that might bite redistributors; despite events in
Arguments:
sctx The current SSL CTX (inbound or outbound)
- host connected host, if client; NULL if server
errstr error string pointer
Returns: TRUE if OK (nothing to set up, or setup worked)
*/
static BOOL
-init_ecdh(SSL_CTX * sctx, host_item * host, uschar ** errstr)
+init_ecdh(SSL_CTX * sctx, uschar ** errstr)
{
#ifdef OPENSSL_NO_ECDH
return TRUE;
#else
-EC_KEY * ecdh;
uschar * exp_curve;
int nid;
BOOL rv;
-if (host) /* No ECDH setup for clients, only for servers */
- return TRUE;
-
# ifndef EXIM_HAVE_ECDH
DEBUG(D_tls)
debug_printf("No OpenSSL API to define ECDH parameters, skipping\n");
)
{
tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve),
- host, NULL, errstr);
+ NULL, NULL, errstr);
return FALSE;
}
-if (!(ecdh = EC_KEY_new_by_curve_name(nid)))
- {
- tls_error(US"Unable to create ec curve", host, NULL, errstr);
- return FALSE;
- }
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ {
+ EC_KEY * ecdh;
+ if (!(ecdh = EC_KEY_new_by_curve_name(nid)))
+ {
+ tls_error(US"Unable to create ec curve", NULL, NULL, errstr);
+ return FALSE;
+ }
-/* The "tmp" in the name here refers to setting a temporary key
-not to the stability of the interface. */
+ /* The "tmp" in the name here refers to setting a temporary key
+ not to the stability of the interface. */
+
+ if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0))
+ tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), NULL, NULL, errstr);
+ else
+ DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve);
+ EC_KEY_free(ecdh);
+ }
-if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0))
- tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL, errstr);
+#else /* v 3.0.0 + */
+
+if ((rv = SSL_CTX_set1_groups(sctx, &nid, 1)) == 0)
+ tls_error(string_sprintf("Error enabling '%s' group", exp_curve), NULL, NULL, errstr);
else
- DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve);
+ DEBUG(D_tls) debug_printf("ECDH: enabled '%s' group\n", exp_curve);
+
+#endif
-EC_KEY_free(ecdh);
return !rv;
# endif /*EXIM_HAVE_ECDH*/
* Expand key and cert file specs *
*************************************************/
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
/*
Arguments:
s SSL connection (not used)
DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength);
-#ifdef EXIM_HAVE_RSA_GENKEY_EX
+# ifdef EXIM_HAVE_RSA_GENKEY_EX
if ( !BN_set_word(bn, (unsigned long)RSA_F4)
|| !(rsa_key = RSA_new())
|| !RSA_generate_key_ex(rsa_key, keylength, bn, NULL)
)
-#else
+# else
if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL)))
-#endif
+# endif
{
ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
}
return rsa_key;
}
+#endif /* pre-3.0.0 */
{
X509 * x509 = NULL;
EVP_PKEY * pkey;
-RSA * rsa;
X509_NAME * name;
uschar * where;
goto err;
where = US"generating pkey";
-if (!(rsa = rsa_callback(NULL, 0, 2048)))
- goto err;
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+ {
+ RSA * rsa;
+ if (!(rsa = rsa_callback(NULL, 0, 2048)))
+ goto err;
-where = US"assigning pkey";
-if (!EVP_PKEY_assign_RSA(pkey, rsa))
- goto err;
+ where = US"assigning pkey";
+ if (!EVP_PKEY_assign_RSA(pkey, rsa))
+ goto err;
+ }
+#else
+pkey = EVP_RSA_gen(2048);
+#endif
X509_set_version(x509, 2); /* N+1 - version 3 */
ASN1_INTEGER_set(X509_get_serialNumber(x509), 1);
if (opt_unset_or_noexpand(tls_dhparam))
{
DEBUG(D_tls) debug_printf("TLS: preloading DH params for server\n");
- if (init_dh(ctx, tls_dhparam, NULL, &dummy_errstr))
+ if (init_dh(ctx, tls_dhparam, &dummy_errstr))
state_server.lib_state.dh = TRUE;
}
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading DH params for server\n");
if (opt_unset_or_noexpand(tls_eccurve))
{
DEBUG(D_tls) debug_printf("TLS: preloading ECDH curve for server\n");
- if (init_ecdh(ctx, NULL, &dummy_errstr))
+ if (init_ecdh(ctx, &dummy_errstr))
state_server.lib_state.ecdh = TRUE;
}
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading ECDH curve for server\n");
#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
/* If we can, preload the server-side cert, key and ocsp */
tpt_dummy_state.lib_state = ob->tls_preload;
-if (opt_unset_or_noexpand(tls_dhparam))
- {
- DEBUG(D_tls) debug_printf("TLS: preloading DH params for transport '%s'\n", t->name);
- if (init_dh(ctx, tls_dhparam, NULL, &dummy_errstr))
- ob->tls_preload.dh = TRUE;
- }
-if (opt_unset_or_noexpand(tls_eccurve))
- {
- DEBUG(D_tls) debug_printf("TLS: preloading ECDH curve for transport '%s'\n", t->name);
- if (init_ecdh(ctx, NULL, &dummy_errstr))
- ob->tls_preload.ecdh = TRUE;
- }
-
#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
if ( opt_set_and_noexpand(ob->tls_certificate)
&& opt_unset_or_noexpand(ob->tls_privatekey))
const EVP_CIPHER * aes_cipher;
uschar aes_key[32]; /* size needed depends on cipher. aes_128 implies 128/8 = 16? */
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
const EVP_MD * hmac_hash;
+# else
+ const uschar * hmac_hashname;
+# endif
uschar hmac_key[16];
time_t renew;
time_t expire;
exim_tk.name[0] = 'E';
exim_tk.aes_cipher = EVP_aes_256_cbc();
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
exim_tk.hmac_hash = EVP_sha256();
+# else
+exim_tk.hmac_hashname = US "sha256";
+# endif
exim_tk.expire = t + ssl_session_timeout;
exim_tk.renew = t + ssl_session_timeout/2;
}
: NULL;
}
+
+static int
+tk_hmac_init(
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ HMAC_CTX * hctx,
+#else
+ EVP_MAC_CTX * hctx,
+#endif
+ exim_stek * key
+ )
+{
+/*XXX will want these dependent on the ssl session strength */
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
+ key->hmac_hash, NULL);
+#else
+ {
+ OSSL_PARAM params[3];
+ uschar * hk = string_copy(key->hmac_hashname); /* need nonconst */
+ params[0] = OSSL_PARAM_construct_octet_string("key", key->hmac_key, sizeof(key->hmac_key));
+ params[1] = OSSL_PARAM_construct_utf8_string("digest", CS hk, 0);
+ params[2] = OSSL_PARAM_construct_end();
+ if (EVP_MAC_CTX_set_params(hctx, params) == 0)
+ {
+ DEBUG(D_tls) debug_printf("EVP_MAC_CTX_set_params: %s\n",
+ ERR_reason_error_string(ERR_get_error()));
+ return 0; /* error in mac initialisation */
+ }
+}
+#endif
+return 1;
+}
+
/* Callback for session tickets, on server */
static int
ticket_key_callback(SSL * ssl, uschar key_name[16],
- uschar * iv, EVP_CIPHER_CTX * c_ctx, HMAC_CTX * hctx, int enc)
+ uschar * iv, EVP_CIPHER_CTX * c_ctx,
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ HMAC_CTX * hctx,
+#else
+ EVP_MAC_CTX * hctx,
+#endif
+ int enc)
{
tls_support * tlsp = state_server.tlsp;
exim_stek * key;
memcpy(key_name, key->name, 16);
DEBUG(D_tls) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - time(NULL));
- /*XXX will want these dependent on the ssl session strength */
- HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
- key->hmac_hash, NULL);
+ if (tk_hmac_init(hctx, key) == 0) return 0;
EVP_EncryptInit_ex(c_ctx, key->aes_cipher, NULL, key->aes_key, iv);
DEBUG(D_tls) debug_printf("ticket created\n");
return 0;
}
- HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
- key->hmac_hash, NULL);
+ if (tk_hmac_init(hctx, key) == 0) return 0;
EVP_DecryptInit_ex(c_ctx, key->aes_cipher, NULL, key->aes_key, iv);
DEBUG(D_tls) debug_printf("ticket usable, STEK expire " TIME_T_FMT "\n", key->expire - now);
return key->renew < now ? 2 : 1;
}
}
-#endif
+#endif /* !DISABLE_TLS_RESUME */
SSL_CTX_set_tlsext_servername_arg(server_sni, state);
}
-if ( !init_dh(server_sni, state->dhparam, NULL, &dummy_errstr)
- || !init_ecdh(server_sni, NULL, &dummy_errstr)
+if ( !init_dh(server_sni, state->dhparam, &dummy_errstr)
+ || !init_ecdh(server_sni, &dummy_errstr)
)
goto bad;
* Callback to handle ALPN *
*************************************************/
-/* SSL_CTX_set_alpn_select_cb() */
-/* Called on server when client offers ALPN, after the SNI callback.
-If set and not e?smtp then we dump the connection */
+/* Called on server if tls_alpn nonblank after expansion,
+when client offers ALPN, after the SNI callback.
+If set and not matching the list then we dump the connection */
static int
tls_server_alpn_cb(SSL *ssl, const uschar ** out, uschar * outlen,
const uschar * in, unsigned int inlen, void * arg)
{
-const exim_openssl_state_st * state = arg;
-
+server_seen_alpn = TRUE;
DEBUG(D_tls)
{
debug_printf("Received TLS ALPN offer:");
if (pos + 1 + siz > inlen) siz = inlen - pos - 1;
debug_printf(" '%.*s'", siz, in + pos + 1);
}
- debug_printf("\n");
+ debug_printf(". Our list: '%s'\n", tls_alpn);
}
/* Look for an acceptable ALPN */
+
if ( inlen > 1 /* at least one name */
&& in[0]+1 == inlen /* filling the vector, so exactly one name */
- && ( Ustrncmp(in+1, "smtp", in[0]) == 0
- || Ustrncmp(in+1, "esmtp", in[0]) == 0
- ) )
+ )
{
- *out = in; /* we checked for exactly one, so can just point to it */
- *outlen = inlen;
- return SSL_TLSEXT_ERR_OK; /* use ALPN */
+ const uschar * list = tls_alpn;
+ int sep = 0;
+ for (uschar * name; name = string_nextinlist(&list, &sep, NULL, 0); )
+ if (Ustrncmp(in+1, name, in[0]) == 0)
+ {
+ *out = in+1; /* we checked for exactly one, so can just point to it */
+ *outlen = inlen;
+ return SSL_TLSEXT_ERR_OK; /* use ALPN */
+ }
}
-/* Reject unacceptable ALPN */
-/* This will be fatal to the TLS conn; would be nice to kill TCP also */
+/* More than one name from clilent, or name did not match our list. */
+
+/* This will be fatal to the TLS conn; would be nice to kill TCP also.
+Maybe as an option in future; for now leave control to the config (must-tls). */
+
+DEBUG(D_tls) debug_printf("TLS ALPN rejected\n");
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
#endif /* EXIM_HAVE_ALPN */
const X509 * cert_sent = SSL_get_certificate(s);
const ASN1_INTEGER * cert_serial = X509_get0_serialNumber(cert_sent);
const BIGNUM * cert_bn = ASN1_INTEGER_to_BN(cert_serial, NULL);
- const X509_NAME * cert_issuer = X509_get_issuer_name(cert_sent);
- uschar * chash;
- uint chash_len;
for (; olist; olist = olist->next)
{
/* Initialize with DH parameters if supplied */
/* Initialize ECDH temp key parameter selection */
-if (state->lib_state.dh)
- { DEBUG(D_tls) debug_printf("TLS: DH params were preloaded\n"); }
-else
- if (!init_dh(ctx, state->dhparam, host, errstr)) return DEFER;
+if (!host)
+ {
+ if (state->lib_state.dh)
+ { DEBUG(D_tls) debug_printf("TLS: DH params were preloaded\n"); }
+ else
+ if (!init_dh(ctx, state->dhparam, errstr)) return DEFER;
-if (state->lib_state.ecdh)
- { DEBUG(D_tls) debug_printf("TLS: ECDH curve was preloaded\n"); }
-else
- if (!init_ecdh(ctx, host, errstr)) return DEFER;
+ if (state->lib_state.ecdh)
+ { DEBUG(D_tls) debug_printf("TLS: ECDH curve was preloaded\n"); }
+ else
+ if (!init_ecdh(ctx, errstr)) return DEFER;
+ }
/* Set up certificate and key (and perhaps OCSP info) */
tls_certificate */
SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb);
SSL_CTX_set_tlsext_servername_arg(ctx, state);
+
# ifdef EXIM_HAVE_ALPN
- SSL_CTX_set_alpn_select_cb(ctx, tls_server_alpn_cb, state);
+ if (tls_alpn && *tls_alpn)
+ {
+ uschar * exp_alpn;
+ if ( expand_check(tls_alpn, US"tls_alpn", &exp_alpn, errstr)
+ && *exp_alpn && !isblank(*exp_alpn))
+ {
+ tls_alpn = exp_alpn; /* subprocess so ok to overwrite */
+ SSL_CTX_set_alpn_select_cb(ctx, tls_server_alpn_cb, state);
+ }
+ else
+ tls_alpn = NULL;
+ }
# endif
}
# ifndef DISABLE_OCSP
{
BIO * bp;
STACK_OF(X509) * verify_stack = *vp;
-X509 * x;
if (verify_stack)
while (sk_X509_num(verify_stack) > 0)
else
goto skip_certs;
- {
+ {
uschar * expcerts;
if (!expand_check(tls_verify_certificates, US"tls_verify_certificates",
&expcerts, errstr))
if (expcerts && *expcerts)
setup_cert_verify(ctx, server_verify_optional, verify_callback_server);
- }
+ }
skip_certs: ;
#ifndef DISABLE_TLS_RESUME
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
SSL_CTX_set_tlsext_ticket_key_cb(ctx, ticket_key_callback);
/* despite working, appears to always return failure, so ignoring */
+# else
+SSL_CTX_set_tlsext_ticket_key_evp_cb(ctx, ticket_key_callback);
+/* despite working, appears to always return failure, so ignoring */
+# endif
#endif
+
#ifdef OPENSSL_HAVE_NUM_TICKETS
# ifndef DISABLE_TLS_RESUME
SSL_CTX_set_num_tickets(ctx, tls_in.host_resumable ? 1 : 0);
}
#endif
+#ifdef EXIM_HAVE_ALPN
+/* If require-alpn, check server_seen_alpn here. Else abort TLS */
+if (!tls_alpn || !*tls_alpn)
+ { DEBUG(D_tls) debug_printf("TLS: was not watching for ALPN\n"); }
+else if (!server_seen_alpn)
+ if (verify_check_host(&hosts_require_alpn) == OK)
+ {
+ /* We'd like to send a definitive Alert but OpenSSL provides no facility */
+ SSL_shutdown(ssl);
+ tls_error(US"handshake", NULL, US"ALPN required but not negotiated", errstr);
+ return FAIL;
+ }
+ else
+ { DEBUG(D_tls) debug_printf("TLS: no ALPN presented in handshake\n"); }
+else DEBUG(D_tls)
+ {
+ const uschar * name;
+ unsigned len;
+ SSL_get0_alpn_selected(ssl, &name, &len);
+ if (len && name)
+ debug_printf("ALPN negotiated: '%.*s'\n", (int)*name, name+1);
+ else
+ debug_printf("ALPN: no protocol negotiated\n");
+ }
+#endif
+
+
/* TLS has been set up. Record data for the connection,
adjust the input functions to read via TLS, and initialize things. */
receive_getc = tls_getc;
receive_getbuf = tls_getbuf;
receive_get_cache = tls_get_cache;
+receive_hasc = tls_hasc;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
-receive_smtp_buffered = tls_smtp_buffered;
tls_in.active.sock = fileno(smtp_out);
tls_in.active.tls_ctx = NULL; /* not using explicit ctx for server-side */
else
return OK;
- {
+ {
uschar * expcerts;
if (!expand_check(ob->tls_verify_certificates, US"tls_verify_certificates",
&expcerts, errstr))
if (expcerts && *expcerts)
setup_cert_verify(ctx, client_verify_optional, verify_callback_client);
- }
+ }
if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK)
{
#endif /* !DISABLE_TLS_RESUME */
+#ifdef EXIM_HAVE_ALPN
+/* Expand and convert an Exim list to an ALPN list. False return for fail.
+NULL plist return for silent no-ALPN.
+*/
+
+static BOOL
+tls_alpn_plist(const uschar * tls_alpn, const uschar ** plist, unsigned * plen,
+ uschar ** errstr)
+{
+uschar * exp_alpn;
+
+if (!expand_check(tls_alpn, US"tls_alpn", &exp_alpn, errstr))
+ return FALSE;
+
+if (!exp_alpn)
+ {
+ DEBUG(D_tls) debug_printf("Setting TLS ALPN forced to fail, not sending\n");
+ *plist = NULL;
+ }
+else
+ {
+ /* The server implementation only accepts exactly one protocol name
+ but it's little extra code complexity in the client. */
+
+ const uschar * list = exp_alpn;
+ uschar * p = store_get(Ustrlen(exp_alpn), is_tainted(exp_alpn)), * s, * t;
+ int sep = 0;
+ uschar len;
+
+ for (t = p; s = string_nextinlist(&list, &sep, NULL, 0); t += len)
+ {
+ *t++ = len = (uschar) Ustrlen(s);
+ memcpy(t, s, len);
+ }
+ *plist = (*plen = t - p) ? p : NULL;
+ }
+return TRUE;
+}
+#endif /* EXIM_HAVE_ALPN */
+
+
/*************************************************
* Start a TLS session in a client *
*************************************************/
}
}
+if (ob->tls_alpn)
+#ifdef EXIM_HAVE_ALPN
+ {
+ const uschar * plist;
+ unsigned plen;
+
+ if (!tls_alpn_plist(ob->tls_alpn, &plist, &plen, errstr))
+ return FALSE;
+ if (plist)
+ if (SSL_set_alpn_protos(exim_client_ctx->ssl, plist, plen) != 0)
+ {
+ tls_error(US"alpn init", host, NULL, errstr);
+ return FALSE;
+ }
+ else
+ DEBUG(D_tls) debug_printf("Setting TLS ALPN '%s'\n", ob->tls_alpn);
+ }
+#else
+ log_write(0, LOG_MAIN, "ALPN unusable with this OpenSSL library version; ignoring \"%s\"\n",
+ ob->tls_alpn);
+#endif
+
#ifdef SUPPORT_DANE
if (conn_args->dane)
if (dane_tlsa_load(exim_client_ctx->ssl, host, &conn_args->tlsa_dnsa, errstr) != OK)
tls_client_resume_posthandshake(exim_client_ctx, tlsp);
#endif
+#ifdef EXIM_HAVE_ALPN
+if (ob->tls_alpn) /* We requested. See what was negotiated. */
+ {
+ const uschar * name;
+ unsigned len;
+
+ SSL_get0_alpn_selected(exim_client_ctx->ssl, &name, &len);
+ if (len > 0)
+ { DEBUG(D_tls) debug_printf("ALPN negotiated %u: '%.*s'\n", len, (int)*name, name+1); }
+ else if (verify_check_given_host(CUSS &ob->hosts_require_alpn, host) == OK)
+ {
+ /* Would like to send a relevant fatal Alert, but OpenSSL has no API */
+ tls_error(US"handshake", host, US"ALPN required but not negotiated", errstr);
+ return FALSE;
+ }
+ }
+#endif
+
#ifdef SSL_get_extms_support
tlsp->ext_master_secret = SSL_get_extms_support(exim_client_ctx->ssl) == 1;
#endif
return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
}
+BOOL
+tls_hasc(void)
+{
+return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm;
+}
+
uschar *
tls_getbuf(unsigned * len)
{
void
-tls_get_cache(void)
+tls_get_cache(unsigned lim)
{
#ifndef DISABLE_DKIM
int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm;
+debug_printf("tls_get_cache\n");
+if (n > lim)
+ n = lim;
if (n > 0)
dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n);
#endif
BOOL
-tls_could_read(void)
+tls_could_getc(void)
{
return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm
|| SSL_pending(state_server.lib_state.lib_ssl) > 0;
receive_getc = smtp_getc;
receive_getbuf = smtp_getbuf;
receive_get_cache = smtp_get_cache;
+ receive_hasc = smtp_hasc;
receive_ungetc = smtp_ungetc;
receive_feof = smtp_feof;
receive_ferror = smtp_ferror;
- receive_smtp_buffered = smtp_buffered;
tls_in.active.tls_ctx = NULL;
tls_in.sni = NULL;
/* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */
git://git.exim.org / exim.git / blobdiff