diff options
Diffstat (limited to 'src/src/tls-openssl.c')
| -rw-r--r-- | src/src/tls-openssl.c | 83 |
1 files changed, 58 insertions, 25 deletions
diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c index 4c61fc0e6..22750d273 100644 --- a/src/src/tls-openssl.c +++ b/src/src/tls-openssl.c @@ -94,6 +94,10 @@ change this guard and punt the issue for a while longer. */ # define EXIM_HAVE_OPENSSL_CIPHER_GET_ID #endif +#if !defined(LIBRESSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER >= 0x030000000L) +# define EXIM_HAVE_EXPORT_CHNL_BNGNG +#endif + #if !defined(LIBRESSL_VERSION_NUMBER) \ || LIBRESSL_VERSION_NUMBER >= 0x20010000L # if !defined(OPENSSL_NO_ECDH) @@ -111,11 +115,16 @@ change this guard and punt the issue for a while longer. */ # define OPENSSL_HAVE_KEYLOG_CB # define OPENSSL_HAVE_NUM_TICKETS # define EXIM_HAVE_OPENSSL_CIPHER_STD_NAME +# define EXIM_HAVE_EXP_CHNL_BNGNG # else # define OPENSSL_BAD_SRVR_OURCERT # endif #endif +#if !defined(LIBRESSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER >= 0x010002000L) +# define EXIM_HAVE_EXPORT_CHNL_BNGNG +#endif + #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile" # define DISABLE_OCSP @@ -3170,6 +3179,52 @@ tls_dump_keylog(SSL * ssl) } +/* Channel-binding info for authenticators +See description in https://paquier.xyz/postgresql-2/channel-binding-openssl/ +for pre-TLS1.3 +*/ + +static void +tls_get_channel_binding(SSL * ssl, tls_support * tlsp, const void * taintval) +{ +uschar c, * s; +size_t len; + +#ifdef EXIM_HAVE_EXPORT_CHNL_BNGNG +if (SSL_version(ssl) >= TLS1_3_VERSION) + { + /* It's not documented by OpenSSL how big the output buffer must be. + The OpenSSL testcases use 80 bytes but don't say why. The GnuTLS impl only + serves out 32B. RFC 9266 says it is 32B. + Interop fails unless we use the same each end. */ + len = 32; + + tlsp->channelbind_exporter = TRUE; + taintval = GET_UNTAINTED; + if (SSL_export_keying_material(ssl, + s = store_get((int)len, taintval), len, + "EXPORTER-Channel-Binding", (size_t) 24, + NULL, 0, 0) != 1) + len = 0; + } +else +#endif + { + len = SSL_get_peer_finished(ssl, &c, 0); + len = SSL_get_peer_finished(ssl, s = store_get((int)len, taintval), len); + } + +if (len > 0) + { + int old_pool = store_pool; + store_pool = POOL_PERM; + tlsp->channelbinding = b64encode_taint(CUS s, (int)len, taintval); + store_pool = old_pool; + DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p %p\n", tlsp->channelbinding, tlsp); + } +} + + /************************************************* * Start a TLS session in a server * *************************************************/ @@ -3446,6 +3501,7 @@ else DEBUG(D_tls) adjust the input functions to read via TLS, and initialize things. */ #ifdef SSL_get_extms_support +/*XXX what does this return for tls1.3 ? */ tls_in.ext_master_secret = SSL_get_extms_support(ssl) == 1; #endif peer_cert(ssl, &tls_in, peerdn, sizeof(peerdn)); @@ -3478,19 +3534,7 @@ DEBUG(D_tls) tls_in.ourcert = crt ? X509_dup(crt) : NULL; } -/* Channel-binding info for authenticators -See description in https://paquier.xyz/postgresql-2/channel-binding-openssl/ */ - { - uschar c, * s; - size_t len = SSL_get_peer_finished(ssl, &c, 0); - int old_pool = store_pool; - - SSL_get_peer_finished(ssl, s = store_get((int)len, GET_UNTAINTED), len); - store_pool = POOL_PERM; - tls_in.channelbinding = b64encode_taint(CUS s, (int)len, GET_UNTAINTED); - store_pool = old_pool; - DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p\n", tls_in.channelbinding); - } +tls_get_channel_binding(ssl, &tls_in, GET_UNTAINTED); /* Only used by the server-side tls (tls_in), including tls_getc. Client-side (tls_out) reads (seem to?) go via @@ -4168,18 +4212,7 @@ tlsp->cipher_stdname = cipher_stdname_ssl(exim_client_ctx->ssl); } /*XXX will this work with continued-TLS? */ -/* Channel-binding info for authenticators */ - { - uschar c, * s; - size_t len = SSL_get_finished(exim_client_ctx->ssl, &c, 0); - int old_pool = store_pool; - - SSL_get_finished(exim_client_ctx->ssl, s = store_get((int)len, GET_TAINTED), len); - store_pool = POOL_PERM; - tlsp->channelbinding = b64encode_taint(CUS s, (int)len, GET_TAINTED); - store_pool = old_pool; - DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p %p\n", tlsp->channelbinding, tlsp); - } +tls_get_channel_binding(exim_client_ctx->ssl, tlsp, GET_TAINTED); tlsp->active.sock = cctx->sock; tlsp->active.tls_ctx = exim_client_ctx; |