Here's an updated patch that that: - Fixes a few typos. - Uses Racket's I/O system to read the Diffie-Hellman parameters.
Things that are not yet added in yet: - All the other elliptic curve names used in TLS. On Mon, Feb 10, 2014 at 08:36:02PM -0500, Edward Lee wrote: > On Mon, Feb 10, 2014 at 06:37:56PM -0500, Ryan Culpepper wrote: > > On 02/08/2014 05:52 PM, Edward Lee wrote: > > >Hi. > > > > > >Racket's OpenSSL bindings do not currently enable the ECDH(E) and the > > >DHE ciphers, which are needed for perfect forward secrecy. > > > > > >I've attached a patch that: > > > - Embeds reasonable defaults for DHE mode. > > > - Adds two functions, ssl-server-context-enable-dhe! and > > > ssl-server-context-enable-ecdhe! that when given > > > DHE/ECDHE setup arguments (for DHE, a DH parameter file path, > > > for ECDHE, the name of one of the built-in OpenSSL elliptic curves > > > [currently, only secp521r1]) > > > - (unrelated, but also useful) Adds bindings for TLS 1.1/1.2-only > > > server/client contexts. > > > > > >This patch is currently a work in progress (it currently only supports > > >one elliptic curve name) that works well enough for what I am using it > > >for, but I'm interested in getting this patch upstream. > > > > Here are a few comments: > > > > What is SSL_CTRL_SET_ECDH_AUTO? I couldn't find it in the openssl > > headers, and I searched a few recent versions. It seems unused here, > > anyway. > It's not defined in OpenSSL 1.0.1, I think. It can be used for enabling > ECDH(E) in OpenSSL >= 1.0.2, with OpenSSL automatically selecting the > curve - <https://www.openssl.org/news/changelog.html>, "Support for > automatic EC temporary key parameter selection..." > > > > I think it would be better to read the DH params file into memory > > using Racket file operations and then use a memory BIO for > > PEM_read_bio_DHparams. Two reasons: the file access will then > > automatically go through Racket's security-guard checks, and the > > file read will go through Racket's IO system, so if the read blocks > > it won't block all Racket threads. > I will investigate this, and time permitting, will change my patch to > use Racket's IO system for loading the parameters. > > > > In ...enable-ecdhe!, the 'case' form doesn't need 'quote'. It should > > be this instead: > > > > (case name > > [(secp521r1) NID_secp521r1] > > [else ___]) > > > > As it is, the function will accept 'quote as the name of a curve. > Thanks for pointing this out. > > > > >What's the exact process for this? > > > > If you have a github account, you can fork the repo there and submit > > a pull request. But we can certainly handle patches like this too. > > > > Ryan > Great, thanks. > > --Edward > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev
diff --git a/racket/collects/openssl/dh4096.pem b/racket/collects/openssl/dh4096.pem new file mode 100644 index 0000000..1b35ad8 --- /dev/null +++ b/racket/collects/openssl/dh4096.pem @@ -0,0 +1,18 @@ +-----BEGIN DH PARAMETERS----- +MIICCAKCAgEA+hRyUsFN4VpJ1O8JLcCo/VWr19k3BCgJ4uk+d+KhehjdRqNDNyOQ +l/MOyQNQfWXPeGKmOmIig6Ev/nm6Nf9Z2B1h3R4hExf+zTiHnvVPeRBhjdQi81rt +Xeoh6TNrSBIKIHfUJWBh3va0TxxjQIs6IZOLeVNRLMqzeylWqMf49HsIXqbcokUS +Vt1BkvLdW48j8PPv5DsKRN3tloTxqDJGo9tKvj1Fuk74A+Xda1kNhB7KFlqMyN98 +VETEJ6c7KpfOo30mnK30wqw3S8OtaIR/maYX72tGOno2ehFDkq3pnPtEbD2CScxc +alJC+EL7RPk5c/tgeTvCngvc1KZn92Y//EI7G9tPZtylj2b56sHtMftIoYJ9+ODM +sccD5Piz/rejE3Ome8EOOceUSCYAhXn8b3qvxVI1ddd1pED6FHRhFvLrZxFvBEM9 +ERRMp5QqOaHJkM+Dxv8Cj6MqrCbfC4u+ZErxodzuusgDgvZiLF22uxMZbobFWyte +OvOzKGtwcTqO/1wV5gKkzu1ZVswVUQd5Gg8lJicwqRWyyNRczDDoG9jVDxmogKTH +AaqLulO7R8Ifa1SwF2DteSGVtgWEN8gDpN3RBmmPTDngyF2DHb5qmpnznwtFKdTL +KWbuHn491xNO25CQWMtem80uKw+pTnisBRF/454n1Jnhub144YRBoN8CAQI= +-----END DH PARAMETERS----- + +These are the 4096 bit DH parameters from "Assigned Number for SKIP Protocols" +(http://www.skip-vpn.org/spec/numbers.html). +See there for how they were generated. +Note that g is not a generator, but this is not a problem since p is a safe prime. diff --git a/racket/collects/openssl/mzssl.rkt b/racket/collects/openssl/mzssl.rkt index 2f16517..e6ffedb 100644 --- a/racket/collects/openssl/mzssl.rkt +++ b/racket/collects/openssl/mzssl.rkt @@ -34,6 +34,7 @@ TO DO: racket/tcp racket/string racket/lazy-require + racket/runtime-path "libcrypto.rkt" "libssl.rkt") (lazy-require @@ -41,7 +42,9 @@ TO DO: ["private/macosx.rkt" (load-macosx-keychain)]) (define protocol-symbol/c - (or/c 'sslv2-or-v3 'sslv2 'sslv3 'tls)) + (or/c 'sslv2-or-v3 'sslv2 'sslv3 'tls 'tls11 'tls12)) +(define curves/c + (or/c 'secp521r1)) (define verify-source/c (or/c path-string? @@ -50,6 +53,7 @@ TO DO: (list/c 'macosx-keychain path-string?))) (provide + ssl-dh-param-path (contract-out [ssl-available? boolean?] [ssl-load-fail-reason (or/c #f string?)] @@ -59,6 +63,10 @@ TO DO: (c-> ssl-client-context?)] [ssl-make-server-context (->* () (protocol-symbol/c) ssl-server-context?)] + [ssl-server-context-enable-dhe! + (->* (ssl-server-context?) (path-string?) void?)] + [ssl-server-context-enable-ecdhe! + (->* (ssl-server-context?) (curves/c) void?)] [ssl-client-context? (c-> any/c boolean?)] [ssl-server-context? @@ -185,6 +193,8 @@ TO DO: (define-cpointer-type _X509*) (define-cpointer-type _ASN1_STRING*) (define-cpointer-type _STACK*) +(define-cpointer-type _DH*) +(define-cpointer-type _EC_KEY*) (define-cstruct _GENERAL_NAME ([type _int] [d _ASN1_STRING*])) (define-ssl SSLv2_client_method (_fun -> _SSL_METHOD*)) @@ -195,9 +205,19 @@ TO DO: (define-ssl SSLv23_server_method (_fun -> _SSL_METHOD*)) (define-ssl TLSv1_client_method (_fun -> _SSL_METHOD*)) (define-ssl TLSv1_server_method (_fun -> _SSL_METHOD*)) +(define-ssl TLSv1_1_client_method (_fun -> _SSL_METHOD*)) +(define-ssl TLSv1_1_server_method (_fun -> _SSL_METHOD*)) +(define-ssl TLSv1_2_client_method (_fun -> _SSL_METHOD*)) +(define-ssl TLSv1_2_server_method (_fun -> _SSL_METHOD*)) + +(define-crypto DH_free (_fun _DH* -> _void) #:wrap (deallocator)) +(define-crypto EC_KEY_free (_fun _EC_KEY* -> _void) #:wrap (deallocator)) + +(define-crypto EC_KEY_new_by_curve_name (_fun _int -> _EC_KEY*) #:wrap (allocator EC_KEY_free)) (define-crypto BIO_s_mem (_fun -> _BIO_METHOD*)) (define-crypto BIO_new (_fun _BIO_METHOD* -> _BIO*/null)) +(define-crypto BIO_new_mem_buf (_fun _pointer _int -> _BIO*)) (define-crypto BIO_free (_fun _BIO* -> _void)) (define-crypto BIO_read (_fun _BIO* _bytes _int -> _int)) @@ -259,6 +279,7 @@ TO DO: (define-ssl SSL_load_error_strings (_fun -> _void)) (define-crypto GENERAL_NAME_free _fpointer) +(define-crypto PEM_read_bio_DHparams (_fun _BIO* _pointer _pointer _pointer -> _DH*) #:wrap (allocator DH_free)) (define-crypto ASN1_STRING_length (_fun _ASN1_STRING* -> _int)) (define-crypto ASN1_STRING_data (_fun _ASN1_STRING* -> _pointer)) (define-crypto X509_NAME_get_index_by_NID (_fun _X509_NAME* _int _int -> _int)) @@ -331,8 +352,20 @@ TO DO: (define NID_commonName 13) (define GEN_DNS 2) +(define SSL_CTRL_SET_ECDH_AUTO 94) +(define SSL_CTRL_OPTIONS 32) +(define SSL_CTRL_SET_TMP_DH 3) +(define SSL_CTRL_SET_TMP_ECDH 4) + +(define SSL_OP_SINGLE_ECDH_USE #x00080000) +(define SSL_OP_SINGLE_DH_USE #x00100000) + +(define NID_secp521r1 716) + (define-mzscheme scheme_make_custodian (_fun _pointer -> _scheme)) +(define-runtime-path ssl-dh-param-path "dh4096.pem") + ;; Make this bigger than 4096 to accommodate at least ;; 4096 of unencrypted data (define BUFFER-SIZE 8000) @@ -467,6 +500,10 @@ TO DO: (if client? SSLv3_client_method SSLv3_server_method)] [(tls) (if client? TLSv1_client_method TLSv1_server_method)] + [(tls11) + (if client? TLSv1_1_client_method TLSv1_1_server_method)] + [(tls12) + (if client? TLSv1_2_client_method TLSv1_2_server_method)] [else (error 'encrypt->method "internal error, unknown encrypt: ~e" e)]))) @@ -515,6 +552,34 @@ TO DO: (define (ssl-seal-context! mzctx) (set-ssl-context-sealed?! mzctx #t)) +(define (ssl-server-context-enable-ecdhe! context [name 'secp521r1]) + (define (symbol->nid name) + (case name + [(secp521r1) NID_secp521r1] + [else NID_secp521r1])) + (define ctx (extract-ctx 'ssl-server-context-enable-ecdhe! #t context)) + (define key (EC_KEY_new_by_curve_name (symbol->nid name))) + (check-valid key 'ssl-server-context-enable-ecdhe! "Could not enable ECDH(E)") + (unless (= 1 (SSL_CTX_ctrl ctx SSL_CTRL_SET_TMP_ECDH 0 key)) + (error 'ssl-server-context-enable-ecdhe! "Could not enable ECDH(E)")) + (SSL_CTX_ctrl ctx SSL_CTRL_OPTIONS SSL_OP_SINGLE_ECDH_USE #f) + (void)) + +(define (ssl-server-context-enable-dhe! context [path ssl-dh-param-path]) + (define params (call-with-input-file path port->bytes)) + (define params-bio (BIO_new_mem_buf params (bytes-length params))) + (check-valid params-bio 'ssl-server-context-enable-dhe! "Diffie-Hellman parameters") + (with-failure + (lambda () + (BIO_free params-bio)) + (define ctx (extract-ctx 'ssl-server-context-enable-dhe! #t context)) + (define dh (PEM_read_bio_DHparams params-bio #f #f #f)) + (check-valid dh 'ssl-server-context-enable-dhe "Diffie-Hellman parameters") + (unless (= 1 (SSL_CTX_ctrl ctx SSL_CTRL_SET_TMP_DH 0 dh)) + (error 'ssl-server-context-enable-dhe "Could not enable DHE")) + (SSL_CTX_ctrl ctx SSL_CTRL_OPTIONS SSL_OP_SINGLE_DH_USE #f) + (void))) + (define (ssl-load-... who load-it ssl-context-or-listener pathname #:try? [try? #f]) (let ([ctx (get-context/listener who ssl-context-or-listener
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