Message ID | 20181010153624.27957-1-arne@rfc2549.org |
---|---|
State | Accepted, archived |
Headers | show |
Series | None | expand |
Hi, On 10-10-18 17:36, Arne Schwabe wrote: > show-tls shows mixed TLS 1.3 and TLS 1.2 ciphers. The ciphersuites > are only valid in tls-cipher or tls-ciphersuites. So this 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 <arne@rfc2549.org> > --- > PATCH V2: refactor common code between mbed and OpenSSL into ssl.c, > fix minor style issues. > > PATCH V3: remove static argument from show_available_tls_ciphers_list > in ssl_openssl.c > > PATCH V4: Style fixes > > src/openvpn/init.c | 1 + > src/openvpn/ssl.c | 24 ++++++++++++++++ > src/openvpn/ssl.h | 14 ++++++++++ > src/openvpn/ssl_backend.h | 12 +++++--- > src/openvpn/ssl_common.h | 6 ---- > src/openvpn/ssl_mbedtls.c | 17 ++++++----- > src/openvpn/ssl_openssl.c | 59 +++++++++++++++++++++++++++------------ > 7 files changed, 96 insertions(+), 37 deletions(-) > > diff --git a/src/openvpn/init.c b/src/openvpn/init.c > index 1b9f19d0..e5e6e85f 100644 > --- a/src/openvpn/init.c > +++ b/src/openvpn/init.c > @@ -1034,6 +1034,7 @@ 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 4f0af286..0b8ccdd3 100644 > --- a/src/openvpn/ssl.c > +++ b/src/openvpn/ssl.c > @@ -4127,6 +4127,30 @@ 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-ciphersuite):\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 781adb94..0bbe1da7 100644 > --- a/src/openvpn/ssl.h > +++ b/src/openvpn/ssl.h > @@ -601,4 +601,18 @@ 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 /* ifndef OPENVPN_SSL_H */ > diff --git a/src/openvpn/ssl_backend.h b/src/openvpn/ssl_backend.h > index 2ae3bcd7..1c244ece 100644 > --- a/src/openvpn/ssl_backend.h > +++ b/src/openvpn/ssl_backend.h > @@ -517,15 +517,19 @@ 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 919ec57c..e5c28508 100644 > --- a/src/openvpn/ssl_common.h > +++ b/src/openvpn/ssl_common.h > @@ -554,10 +554,4 @@ 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 cb71d55a..3a0b5641 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 ba0d1328..99a8719f 100644 > --- a/src/openvpn/ssl_openssl.c > +++ b/src/openvpn/ssl_openssl.c > @@ -60,6 +60,7 @@ > #include <openssl/pkcs12.h> > #include <openssl/rsa.h> > #include <openssl/x509.h> > +#include <openssl/ssl.h> > #ifndef OPENSSL_NO_EC > #include <openssl/ec.h> > #endif > @@ -428,7 +429,8 @@ 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 > @@ -1984,14 +1986,11 @@ 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) > @@ -1999,22 +1998,45 @@ 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) > { > - pair = tls_get_cipher_name_pair(cipher_name, strlen(cipher_name)); > + crypto_msg(M_FATAL, "Cannot create SSL object"); > + } > > - if (NULL == pair) > +#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++) > + { > + 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 (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); > @@ -2023,14 +2045,15 @@ 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); > } > > + > /* > * Show the Elliptic curves that are available for us to use > * in the OpenSSL library. > Looks all good now, thanks! Acked-by: Steffan Karger <steffan@karger.me> -Steffan
Your patch has been applied to the master and release/2.4 branch (long term compatibility). I had to fix one minor bit - it prints For TLS 1.3 and newer (--tls-ciphersuite): but that option is called "--tls-ciphersuites"... I am not really able to make sense of it, though. If I try to specify a TLS 1.3 ciphersuite, to see if it has any effect, all I get is errors in the log ("no valid translation"), and no effect... so maybe something with the --tls-ciphersuites patch is wrong, and this one is only exposing it? Arne, Steffan, could you have a look? This is "master" with OpenSSL 1.1.1: $ src/openvpn/openvpn --verb 4 --tls-ciphersuites TLS_AES_256_GCM_SHA384 --show-tls --tls-cipher TLS-DHE-RSA-WITH-AES-256-CBC-SHA256 Available TLS Ciphers, listed in order of preference: For TLS 1.3 and newer (--tls-ciphersuite): Thu Oct 11 20:32:44 2018 us=310005 No valid translation found for TLS cipher 'TLS_AES_256_GCM_SHA384' TLS_AES_256_GCM_SHA384 TLS_CHACHA20_POLY1305_SHA256 TLS_AES_128_GCM_SHA256 For TLS 1.2 and older (--tls-cipher): TLS-DHE-RSA-WITH-AES-256-CBC-SHA256 .. so "--tls-cipher" is definitely sticking, while "--tls-ciphersuites" leads to a confusing warning (if --verb is high enough), listing the very same cipher(suite) in the next line...? commit 7aeabadd69fca0071152c42d58fee0b565f01eb3 (master) commit e8467c8648f699b221004a9f15d48b8e558049f0 (release/2.4) Author: Arne Schwabe Date: Wed Oct 10 17:36:24 2018 +0200 Add better support for showing TLS 1.3 ciphersuites in --show-tls Signed-off-by: Arne Schwabe <arne@rfc2549.org> Acked-by: Steffan Karger <steffan.karger@fox-it.com> 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 <gert@greenie.muc.de> -- kind regards, Gert Doering
diff --git a/src/openvpn/init.c b/src/openvpn/init.c index 1b9f19d0..e5e6e85f 100644 --- a/src/openvpn/init.c +++ b/src/openvpn/init.c @@ -1034,6 +1034,7 @@ 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 4f0af286..0b8ccdd3 100644 --- a/src/openvpn/ssl.c +++ b/src/openvpn/ssl.c @@ -4127,6 +4127,30 @@ 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-ciphersuite):\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 781adb94..0bbe1da7 100644 --- a/src/openvpn/ssl.h +++ b/src/openvpn/ssl.h @@ -601,4 +601,18 @@ 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 /* ifndef OPENVPN_SSL_H */ diff --git a/src/openvpn/ssl_backend.h b/src/openvpn/ssl_backend.h index 2ae3bcd7..1c244ece 100644 --- a/src/openvpn/ssl_backend.h +++ b/src/openvpn/ssl_backend.h @@ -517,15 +517,19 @@ 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 919ec57c..e5c28508 100644 --- a/src/openvpn/ssl_common.h +++ b/src/openvpn/ssl_common.h @@ -554,10 +554,4 @@ 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 cb71d55a..3a0b5641 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 ba0d1328..99a8719f 100644 --- a/src/openvpn/ssl_openssl.c +++ b/src/openvpn/ssl_openssl.c @@ -60,6 +60,7 @@ #include <openssl/pkcs12.h> #include <openssl/rsa.h> #include <openssl/x509.h> +#include <openssl/ssl.h> #ifndef OPENSSL_NO_EC #include <openssl/ec.h> #endif @@ -428,7 +429,8 @@ 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 @@ -1984,14 +1986,11 @@ 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) @@ -1999,22 +1998,45 @@ 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) { - pair = tls_get_cipher_name_pair(cipher_name, strlen(cipher_name)); + crypto_msg(M_FATAL, "Cannot create SSL object"); + } - if (NULL == pair) +#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++) + { + 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 (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); @@ -2023,14 +2045,15 @@ 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); } + /* * Show the Elliptic curves that are available for us to use * in the OpenSSL library.
show-tls shows mixed TLS 1.3 and TLS 1.2 ciphers. The ciphersuites are only valid in tls-cipher or tls-ciphersuites. So this 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 <arne@rfc2549.org> --- PATCH V2: refactor common code between mbed and OpenSSL into ssl.c, fix minor style issues. PATCH V3: remove static argument from show_available_tls_ciphers_list in ssl_openssl.c PATCH V4: Style fixes src/openvpn/init.c | 1 + src/openvpn/ssl.c | 24 ++++++++++++++++ src/openvpn/ssl.h | 14 ++++++++++ src/openvpn/ssl_backend.h | 12 +++++--- src/openvpn/ssl_common.h | 6 ---- src/openvpn/ssl_mbedtls.c | 17 ++++++----- src/openvpn/ssl_openssl.c | 59 +++++++++++++++++++++++++++------------ 7 files changed, 96 insertions(+), 37 deletions(-)