diff options
author | Ben Laurie <ben@openssl.org> | 2011-11-13 21:55:42 +0000 |
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committer | Ben Laurie <ben@openssl.org> | 2011-11-13 21:55:42 +0000 |
commit | 68b33cc5c7aa1bb98e95bfb4b61c34192a7a50e3 (patch) | |
tree | 8c4298a1cc0487b3223a06764fe5f338f9691ad8 /ssl/ssl_lib.c | |
parent | 4c02cf8ecc4b4cedeb6b6c11185f5d3e49c3cd4a (diff) |
Add Next Protocol Negotiation.
Diffstat (limited to 'ssl/ssl_lib.c')
-rw-r--r-- | ssl/ssl_lib.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index 0a6cf3ad30..596d9b758b 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c @@ -353,6 +353,9 @@ SSL *SSL_new(SSL_CTX *ctx) s->tlsext_ocsp_resplen = -1; CRYPTO_add(&ctx->references,1,CRYPTO_LOCK_SSL_CTX); s->initial_ctx=ctx; +# ifndef OPENSSL_NO_NEXTPROTONEG + s->next_proto_negotiated = NULL; +# endif #endif s->verify_result=X509_V_OK; @@ -586,6 +589,11 @@ void SSL_free(SSL *s) kssl_ctx_free(s->kssl_ctx); #endif /* OPENSSL_NO_KRB5 */ +#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG) + if (s->next_proto_negotiated) + OPENSSL_free(s->next_proto_negotiated); +#endif + OPENSSL_free(s); } @@ -1494,6 +1502,123 @@ int SSL_get_servername_type(const SSL *s) return TLSEXT_NAMETYPE_host_name; return -1; } + +# ifndef OPENSSL_NO_NEXTPROTONEG +/* SSL_select_next_proto implements the standard protocol selection. It is + * expected that this function is called from the callback set by + * SSL_CTX_set_next_proto_select_cb. + * + * The protocol data is assumed to be a vector of 8-bit, length prefixed byte + * strings. The length byte itself is not included in the length. A byte + * string of length 0 is invalid. No byte string may be truncated. + * + * The current, but experimental algorithm for selecting the protocol is: + * + * 1) If the server doesn't support NPN then this is indicated to the + * callback. In this case, the client application has to abort the connection + * or have a default application level protocol. + * + * 2) If the server supports NPN, but advertises an empty list then the + * client selects the first protcol in its list, but indicates via the + * API that this fallback case was enacted. + * + * 3) Otherwise, the client finds the first protocol in the server's list + * that it supports and selects this protocol. This is because it's + * assumed that the server has better information about which protocol + * a client should use. + * + * 4) If the client doesn't support any of the server's advertised + * protocols, then this is treated the same as case 2. + * + * It returns either + * OPENSSL_NPN_NEGOTIATED if a common protocol was found, or + * OPENSSL_NPN_NO_OVERLAP if the fallback case was reached. + */ +int SSL_select_next_proto(unsigned char **out, unsigned char *outlen, const unsigned char *server, unsigned int server_len, const unsigned char *client, unsigned int client_len) + { + unsigned int i, j; + const unsigned char *result; + int status = OPENSSL_NPN_UNSUPPORTED; + + /* For each protocol in server preference order, see if we support it. */ + for (i = 0; i < server_len; ) + { + for (j = 0; j < client_len; ) + { + if (server[i] == client[j] && + memcmp(&server[i+1], &client[j+1], server[i]) == 0) + { + /* We found a match */ + result = &server[i]; + status = OPENSSL_NPN_NEGOTIATED; + goto found; + } + j += client[j]; + j++; + } + i += server[i]; + i++; + } + + /* There's no overlap between our protocols and the server's list. */ + result = client; + status = OPENSSL_NPN_NO_OVERLAP; + + found: + *out = (unsigned char *) result + 1; + *outlen = result[0]; + return status; + } + +/* SSL_get0_next_proto_negotiated sets *data and *len to point to the client's + * requested protocol for this connection and returns 0. If the client didn't + * request any protocol, then *data is set to NULL. + * + * Note that the client can request any protocol it chooses. The value returned + * from this function need not be a member of the list of supported protocols + * provided by the callback. + */ +void SSL_get0_next_proto_negotiated(const SSL *s, const unsigned char **data, unsigned *len) + { + *data = s->next_proto_negotiated; + if (!*data) { + *len = 0; + } else { + *len = s->next_proto_negotiated_len; + } +} + +/* SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a + * TLS server needs a list of supported protocols for Next Protocol + * Negotiation. The returned list must be in wire format. The list is returned + * by setting |out| to point to it and |outlen| to its length. This memory will + * not be modified, but one should assume that the SSL* keeps a reference to + * it. + * + * The callback should return SSL_TLSEXT_ERR_OK if it wishes to advertise. Otherwise, no + * such extension will be included in the ServerHello. */ +void SSL_CTX_set_next_protos_advertised_cb(SSL_CTX *ctx, int (*cb) (SSL *ssl, const unsigned char **out, unsigned int *outlen, void *arg), void *arg) + { + ctx->next_protos_advertised_cb = cb; + ctx->next_protos_advertised_cb_arg = arg; + } + +/* SSL_CTX_set_next_proto_select_cb sets a callback that is called when a + * client needs to select a protocol from the server's provided list. |out| + * must be set to point to the selected protocol (which may be within |in|). + * The length of the protocol name must be written into |outlen|. The server's + * advertised protocols are provided in |in| and |inlen|. The callback can + * assume that |in| is syntactically valid. + * + * The client must select a protocol. It is fatal to the connection if this + * callback returns a value other than SSL_TLSEXT_ERR_OK. + */ +void SSL_CTX_set_next_proto_select_cb(SSL_CTX *ctx, int (*cb) (SSL *s, unsigned char **out, unsigned char *outlen, const unsigned char *in, unsigned int inlen, void *arg), void *arg) + { + ctx->next_proto_select_cb = cb; + ctx->next_proto_select_cb_arg = arg; + } +# endif #endif static unsigned long ssl_session_hash(const SSL_SESSION *a) @@ -1666,6 +1791,10 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth) ret->tlsext_status_cb = 0; ret->tlsext_status_arg = NULL; +# ifndef OPENSSL_NO_NEXTPROTONEG + ret->next_protos_advertised_cb = 0; + ret->next_proto_select_cb = 0; +# endif #endif #ifndef OPENSSL_NO_PSK ret->psk_identity_hint=NULL; |