From: Arne Schwabe Date: Wed, 10 Oct 2018 15:36:24 +0000 (+0200) Subject: Add better support for showing TLS 1.3 ciphersuites in --show-tls X-Git-Tag: v2.4.7~12 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8467c8648f699b221004a9f15d48b8e558049f0;p=thirdparty%2Fopenvpn.git Add better support for showing TLS 1.3 ciphersuites in --show-tls --show-tls shows mixed TLS 1.3 and TLS 1.2 ciphers. The listed ciphers are only valid in either --tls-cipher or --tls-ciphersuites, but it's not clear which is which. This is confusing and not really helpful. This patch modifies show-tls to show separate lists for TLS 1.2 and TLS 1.3. Signed-off-by: Arne Schwabe Acked-by: Steffan Karger Message-Id: <20181010153624.27957-1-arne@rfc2549.org> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg17723.html Signed-off-by: Gert Doering (cherry picked from commit 7aeabadd69fca0071152c42d58fee0b565f01eb3) --- diff --git a/src/openvpn/init.c b/src/openvpn/init.c index f5bdc84b5..586e4ca62 100644 --- a/src/openvpn/init.c +++ b/src/openvpn/init.c @@ -1044,6 +1044,7 @@ print_openssl_info(const struct options *options) if (options->show_tls_ciphers) { show_available_tls_ciphers(options->cipher_list, + options->cipher_list_tls13, options->tls_cert_profile); } if (options->show_curves) diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c index 26d581df0..ca326182e 100644 --- a/src/openvpn/ssl.c +++ b/src/openvpn/ssl.c @@ -4128,6 +4128,30 @@ tls_check_ncp_cipher_list(const char *list) return 0 < strlen(list) && !unsupported_cipher_found; } +void +show_available_tls_ciphers(const char *cipher_list, + const char *cipher_list_tls13, + const char *tls_cert_profile) +{ + printf("Available TLS Ciphers, listed in order of preference:\n"); + +#if (ENABLE_CRYPTO_OPENSSL && OPENSSL_VERSION_NUMBER >= 0x1010100fL) + printf("\nFor TLS 1.3 and newer (--tls-ciphersuites):\n\n"); + show_available_tls_ciphers_list(cipher_list_tls13, tls_cert_profile, true); +#else + (void) cipher_list_tls13; /* Avoid unused warning */ +#endif + + printf("\nFor TLS 1.2 and older (--tls-cipher):\n\n"); + show_available_tls_ciphers_list(cipher_list, tls_cert_profile, false); + + printf("\n" + "Be aware that that whether a cipher suite in this list can actually work\n" + "depends on the specific setup of both peers. See the man page entries of\n" + "--tls-cipher and --show-tls for more details.\n\n" + ); +} + /* * Dump a human-readable rendition of an openvpn packet * into a garbage collectable string which is returned. diff --git a/src/openvpn/ssl.h b/src/openvpn/ssl.h index 7c5da1527..a724419fc 100644 --- a/src/openvpn/ssl.h +++ b/src/openvpn/ssl.h @@ -600,6 +600,19 @@ bool is_hard_reset(int op, int key_method); void delayed_auth_pass_purge(void); + +/* + * Show the TLS ciphers that are available for us to use in the SSL + * library with headers hinting their usage and warnings about usage. + * + * @param cipher_list list of allowed TLS cipher, or NULL. + * @param cipher_list_tls13 list of allowed TLS 1.3+ cipher, or NULL + * @param tls_cert_profile TLS certificate crypto profile name. + */ +void +show_available_tls_ciphers(const char *cipher_list, + const char *cipher_list_tls13, + const char *tls_cert_profile); #endif /* ENABLE_CRYPTO */ #endif /* ifndef OPENVPN_SSL_H */ diff --git a/src/openvpn/ssl_backend.h b/src/openvpn/ssl_backend.h index 3064f4a43..c614efa6c 100644 --- a/src/openvpn/ssl_backend.h +++ b/src/openvpn/ssl_backend.h @@ -526,15 +526,19 @@ int key_state_read_plaintext(struct key_state_ssl *ks_ssl, struct buffer *buf, void print_details(struct key_state_ssl *ks_ssl, const char *prefix); /* - * Show the TLS ciphers that are available for us to use in the OpenSSL - * library. + * Show the TLS ciphers that are available for us to use in the + * library depending on the TLS version. This function prints + * a list of ciphers without headers/footers. * * @param cipher_list list of allowed TLS cipher, or NULL. * @param tls_cert_profile TLS certificate crypto profile name. + * @param tls13 Select if <=TLS1.2 or TLS1.3+ ciphers + * should be shown */ void -show_available_tls_ciphers(const char *cipher_list, - const char *tls_cert_profile); +show_available_tls_ciphers_list(const char *cipher_list, + const char *tls_cert_profile, + bool tls13); /* * Show the available elliptic curves in the crypto library diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h index c7565d8c5..ac25ffa78 100644 --- a/src/openvpn/ssl_common.h +++ b/src/openvpn/ssl_common.h @@ -556,10 +556,4 @@ struct tls_multi * sessions with the remote peer. */ }; - -#define SHOW_TLS_CIPHER_LIST_WARNING \ - "Be aware that that whether a cipher suite in this list can actually work\n" \ - "depends on the specific setup of both peers. See the man page entries of\n" \ - "--tls-cipher and --show-tls for more details.\n\n" - #endif /* SSL_COMMON_H_ */ diff --git a/src/openvpn/ssl_mbedtls.c b/src/openvpn/ssl_mbedtls.c index 6befb27c3..89b1b67c2 100644 --- a/src/openvpn/ssl_mbedtls.c +++ b/src/openvpn/ssl_mbedtls.c @@ -1340,9 +1340,15 @@ print_details(struct key_state_ssl *ks_ssl, const char *prefix) } void -show_available_tls_ciphers(const char *cipher_list, - const char *tls_cert_profile) +show_available_tls_ciphers_list(const char *cipher_list, + const char *tls_cert_profile, + bool tls13) { + if (tls13) + { + /* mbed TLS has no TLS 1.3 support currently */ + return; + } struct tls_root_ctx tls_ctx; const int *ciphers = mbedtls_ssl_list_ciphersuites(); @@ -1355,18 +1361,11 @@ show_available_tls_ciphers(const char *cipher_list, ciphers = tls_ctx.allowed_ciphers; } -#ifndef ENABLE_SMALL - printf("Available TLS Ciphers,\n"); - printf("listed in order of preference:\n\n"); -#endif - while (*ciphers != 0) { printf("%s\n", mbedtls_ssl_get_ciphersuite_name(*ciphers)); ciphers++; } - printf("\n" SHOW_TLS_CIPHER_LIST_WARNING); - tls_ctx_free(&tls_ctx); } diff --git a/src/openvpn/ssl_openssl.c b/src/openvpn/ssl_openssl.c index 0daf54396..813f00778 100644 --- a/src/openvpn/ssl_openssl.c +++ b/src/openvpn/ssl_openssl.c @@ -423,7 +423,8 @@ tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers) } void -convert_tls13_list_to_openssl(char* openssl_ciphers, size_t len, const char *ciphers) +convert_tls13_list_to_openssl(char *openssl_ciphers, size_t len, + const char *ciphers) { /* * OpenSSL (and official IANA) cipher names have _ in them. We @@ -1833,14 +1834,11 @@ print_details(struct key_state_ssl *ks_ssl, const char *prefix) } void -show_available_tls_ciphers(const char *cipher_list, - const char *tls_cert_profile) +show_available_tls_ciphers_list(const char *cipher_list, + const char *tls_cert_profile, + const bool tls13) { struct tls_root_ctx tls_ctx; - SSL *ssl; - const char *cipher_name; - const tls_cipher_name_pair *pair; - int priority = 0; tls_ctx.ctx = SSL_CTX_new(SSLv23_method()); if (!tls_ctx.ctx) @@ -1848,22 +1846,45 @@ show_available_tls_ciphers(const char *cipher_list, crypto_msg(M_FATAL, "Cannot create SSL_CTX object"); } - ssl = SSL_new(tls_ctx.ctx); - if (!ssl) +#if (OPENSSL_VERSION_NUMBER >= 0x1010100fL) + if (tls13) { - crypto_msg(M_FATAL, "Cannot create SSL object"); + SSL_CTX_set_min_proto_version(tls_ctx.ctx, TLS1_3_VERSION); + } + else +#endif + { + SSL_CTX_set_max_proto_version(tls_ctx.ctx, TLS1_2_VERSION); } tls_ctx_set_cert_profile(&tls_ctx, tls_cert_profile); tls_ctx_restrict_ciphers(&tls_ctx, cipher_list); - printf("Available TLS Ciphers,\n"); - printf("listed in order of preference:\n\n"); - while ((cipher_name = SSL_get_cipher_list(ssl, priority++))) + SSL *ssl = SSL_new(tls_ctx.ctx); + if (!ssl) + { + crypto_msg(M_FATAL, "Cannot create SSL object"); + } + +#if (OPENSSL_VERSION_NUMBER < 0x1010000fL) + STACK_OF(SSL_CIPHER) *sk = SSL_get_ciphers(ssl); +#else + STACK_OF(SSL_CIPHER) *sk = SSL_get1_supported_ciphers(ssl); +#endif + for (int i=0;i < sk_SSL_CIPHER_num(sk);i++) { - pair = tls_get_cipher_name_pair(cipher_name, strlen(cipher_name)); + const SSL_CIPHER *c = sk_SSL_CIPHER_value(sk, i); + + const char *cipher_name = SSL_CIPHER_get_name(c); + + const tls_cipher_name_pair *pair = + tls_get_cipher_name_pair(cipher_name, strlen(cipher_name)); - if (NULL == pair) + if (tls13) + { + printf("%s\n", cipher_name); + } + else if (NULL == pair) { /* No translation found, print warning */ printf("%s (No IANA name known to OpenVPN, use OpenSSL name.)\n", cipher_name); @@ -1872,10 +1893,10 @@ show_available_tls_ciphers(const char *cipher_list, { printf("%s\n", pair->iana_name); } - } - printf("\n" SHOW_TLS_CIPHER_LIST_WARNING); - +#if (OPENSSL_VERSION_NUMBER >= 0x1010000fL) + sk_SSL_CIPHER_free(sk); +#endif SSL_free(ssl); SSL_CTX_free(tls_ctx.ctx); }