diff options
Diffstat (limited to 'lib/ssl/doc/src/ssl.xml')
| -rw-r--r-- | lib/ssl/doc/src/ssl.xml | 202 |
1 files changed, 174 insertions, 28 deletions
diff --git a/lib/ssl/doc/src/ssl.xml b/lib/ssl/doc/src/ssl.xml index ffee4bd1af..47b0dbc206 100644 --- a/lib/ssl/doc/src/ssl.xml +++ b/lib/ssl/doc/src/ssl.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1999</year><year>2014</year> + <year>1999</year><year>2015</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -38,7 +38,9 @@ <item>ssl requires the crypto and public_key applications.</item> <item>Supported SSL/TLS-versions are SSL-3.0, TLS-1.0, TLS-1.1 and TLS-1.2.</item> - <item>For security reasons sslv2 is not supported.</item> + <item>For security reasons SSL-2.0 is not supported.</item> + <item>For security reasons SSL-3.0 is no longer supported by default, + but may be configured.</item> <item>Ephemeral Diffie-Hellman cipher suites are supported but not Diffie Hellman Certificates cipher suites.</item> <item>Elliptic Curve cipher suites are supported if crypto @@ -49,9 +51,9 @@ <item>IDEA cipher suites are not supported as they have become deprecated by the latest TLS spec so there is not any real motivation to implement them.</item> - <item>CRL and policy certificate extensions are not supported - yet. However CRL verification is supported by public_key, only not integrated - in ssl yet. </item> + <item>CRL validation is supported.</item> + <item>Policy certificate extensions are not supported + yet. </item> <item>Support for 'Server Name Indication' extension client side (RFC 6066 section 3).</item> </list> @@ -87,12 +89,14 @@ |{dh, der_encoded()} | {dhfile, path()} | {ciphers, ciphers()} | {user_lookup_fun, {fun(), term()}}, {psk_identity, string()}, {srp_identity, {string(), string()}} | {ssl_imp, ssl_imp()} | {reuse_sessions, boolean()} | {reuse_session, fun()} + {alpn_advertised_protocols, [binary()]} | + {alpn_preferred_protocols, [binary()]} | {next_protocols_advertised, [binary()]} | {client_preferred_next_protocols, {client | server, [binary()]} | {client | server, [binary()], binary()}} | {log_alert, boolean()} | {server_name_indication, hostname() | disable} </c></p> - <p><c>transportoption() = {cb_info, {CallbackModule::atom(), DataTag::atom(), ClosedTag::atom(), ErrTag:atom()}} + <p><c>transportoption() = {cb_info, {CallbackModule :: atom(), DataTag :: atom(), ClosedTag :: atom(), ErrTag:atom()}} - defaults to {gen_tcp, tcp, tcp_closed, tcp_error}. Can be used to customize the transport layer. The callback module must implement a reliable transport protocol and behave as gen_tcp and in addition have functions corresponding to @@ -136,7 +140,7 @@ </c></p> <p><c>cipher() = rc4_128 | des_cbc | '3des_ede_cbc' - | aes_128_cbc | aes_256_cbc </c></p> + | aes_128_cbc | aes_256_cbc | aes_128_gcm | aes_256_gcm </c></p> <p> <c>hash() = md5 | sha </c></p> @@ -163,7 +167,7 @@ is supplied it will override the certfile option.</item> <tag>{certfile, path()}</tag> - <item>Path to a file containing the user's certificate.</item> + <item>Path to a file containing the user's PEM encoded certificate.</item> <tag>{key, {'RSAPrivateKey'| 'DSAPrivateKey' | 'ECPrivateKey' |'PrivateKeyInfo', der_encoded()}}</tag> <item> The DER encoded users private key. If this option @@ -226,7 +230,7 @@ <p>The verification fun should be defined as:</p> <code> -fun(OtpCert :: #'OTPCertificate'{}, Event :: {bad_cert, Reason :: atom()} | +fun(OtpCert :: #'OTPCertificate'{}, Event :: {bad_cert, Reason :: atom() | {revoked, atom()}} | {extension, #'Extension'{}}, InitialUserState :: term()) -> {valid, UserState :: term()} | {valid_peer, UserState :: term()} | {fail, Reason :: term()} | {unknown, UserState :: term()}. @@ -252,7 +256,7 @@ fun(OtpCert :: #'OTPCertificate'{}, Event :: {bad_cert, Reason :: atom()} | always returns {valid, UserState}, the TLS/SSL handshake will not be terminated with respect to verification failures and the connection will be established. If called with an - extension unknown to the user application the return value + extension unknown to the user application, the return value {unknown, UserState} should be used.</p> <p>The default verify_fun option in verify_peer mode:</p> @@ -283,15 +287,72 @@ fun(OtpCert :: #'OTPCertificate'{}, Event :: {bad_cert, Reason :: atom()} | end, []} </code> -<p>Possible path validation errors: </p> + <p>Possible path validation errors are given on the form {bad_cert, Reason} where Reason is:</p> -<p> {bad_cert, cert_expired}, {bad_cert, invalid_issuer}, {bad_cert, invalid_signature}, {bad_cert, unknown_ca},{bad_cert, selfsigned_peer}, {bad_cert, name_not_permitted}, {bad_cert, missing_basic_constraint}, {bad_cert, invalid_key_usage}</p> + <taglist> + <tag>unknown_ca</tag> + <item>No trusted CA was found in the trusted store. The trusted CA is + normally a so called ROOT CA that is a self-signed cert. Trust may + be claimed for an intermediat CA (trusted anchor does not have to be self signed + according to X-509) by using the option <c>partial_chain</c></item> + + <tag>selfsigned_peer</tag> + <item>The chain consisted only of one self-signed certificate.</item> + + <tag>PKIX X-509-path validation error</tag> + <item> Possible such reasons see <seealso + marker="public_key:public_key#pkix_path_validation-3"> public_key:pkix_path_validation/3 </seealso></item> + </taglist> + </item> + + <tag>{crl_check, boolean() | peer | best_effort }</tag> + <item> + Perform CRL (Certificate Revocation List) verification + <seealso marker="public_key:public_key#pkix_crl_validate-3"> + (public_key:pkix_crls_validate/3)</seealso> on all the certificates during the path validation + <seealso + marker="public_key:public_key#pkix_path_validation-3">(public_key:pkix_path_validation/3) + </seealso> + of the certificate chain. Defaults to false. + + <p><c>peer</c> - check is only performed on + the peer certificate.</p> + + <p><c>best_effort</c> - if certificate revocation status can not be determined + it will be accepted as valid.</p> + + <p>The CA certificates specified for the connection will be used to + construct the certificate chain validating the CRLs.</p> + + <p>The CRLs will be fetched from a local or external cache + <seealso marker="ssl:ssl_crl_cache_api">ssl_crl_cache_api(3)</seealso>.</p> + </item> + + <tag>{crl_cache, {Module :: atom(), {DbHandle :: internal | term(), Args :: list()}}}</tag> + <item> + <p>Module defaults to ssl_crl_cache with <c> DbHandle </c> internal and an + empty argument list. The following arguments may be specified for the internal cache.</p> + <taglist> + <tag>{http, timeout()}</tag> + <item> + Enables fetching of CRLs specified as http URIs in<seealso + marker="public_key:cert_records"> X509 cerificate extensions.</seealso> + Requires the OTP inets application. + </item> + </taglist> + </item> + + <tag>{partial_chain, fun(Chain::[DerCert]) -> {trusted_ca, DerCert} | unknown_ca </tag> + + <item> + Claim an intermediat CA in the chain as trusted. TLS will then perform the public_key:pkix_path_validation/3 + with the selected CA as trusted anchor and the rest of the chain. </item> <tag>{versions, [protocol()]}</tag> <item>TLS protocol versions that will be supported by started clients and servers. This option overrides the application environment option <c>protocol_version</c>. If the - environment option is not set it defaults to all versions supported by the SSL application. See also + environment option is not set it defaults to all versions, except SSL-3.0, supported by the SSL application. See also <seealso marker="ssl:ssl_app">ssl(6)</seealso> </item> @@ -328,11 +389,23 @@ fun(srp, Username :: string(), UserState :: term()) -> </p> </item> + <tag>{padding_check, boolean()}</tag> + <item> + <p> This option only affects TLS-1.0 connections. + If set to false it disables the block cipher padding check + to be able to interoperate with legacy software. + </p> + + <warning><p> Using this option makes TLS vulnerable to + the Poodle attack</p></warning> + + </item> + </taglist> - + </section> - - <section> + + <section> <title>SSL OPTION DESCRIPTIONS - CLIENT SIDE</title> <p>Options described here are client specific or has a slightly different @@ -354,7 +427,20 @@ fun(srp, Username :: string(), UserState :: term()) -> certificates are used during server authentication and when building the client certificate chain. </item> - + + <tag>{alpn_advertised_protocols, [binary()]}</tag> + <item> + <p>The list of protocols supported by the client to be sent to the + server to be used for an Application-Layer Protocol Negotiation (ALPN). + If the server supports ALPN then it will choose a protocol from this + list; otherwise it will fail the connection with a "no_application_protocol" + alert. A server that does not support ALPN will ignore this value.</p> + + <p>The list of protocols must not contain an empty binary.</p> + + <p>The negotiated protocol can be retrieved using the <c>negotiated_protocol/1</c> function.</p> + </item> + <tag>{client_preferred_next_protocols, {Precedence :: server | client, ClientPrefs :: [binary()]}}</tag> <tag>{client_preferred_next_protocols, {Precedence :: server | client, ClientPrefs :: [binary()], Default :: binary()}}</tag> <item> @@ -393,6 +479,23 @@ fun(srp, Username :: string(), UserState :: term()) -> Indication extension will be sent if possible, this option may also be used to disable that behavior.</p> </item> + <tag>{fallback, boolean()}</tag> + <item> + <p> Send special cipher suite TLS_FALLBACK_SCSV to avoid undesired TLS version downgrade. + Defaults to false</p> + <warning><p>Note this option is not needed in normal TLS usage and should not be used + to implement new clients. But legacy clients that that retries connections in the following manner</p> + + <p><c> ssl:connect(Host, Port, [...{versions, ['tlsv2', 'tlsv1.1', 'tlsv1', 'sslv3']}])</c></p> + <p><c> ssl:connect(Host, Port, [...{versions, [tlsv1.1', 'tlsv1', 'sslv3']}, {fallback, true}])</c></p> + <p><c> ssl:connect(Host, Port, [...{versions, ['tlsv1', 'sslv3']}, {fallback, true}]) </c></p> + <p><c> ssl:connect(Host, Port, [...{versions, ['sslv3']}, {fallback, true}]) </c></p> + + <p>may use it to avoid undesired TLS version downgrade. Note that TLS_FALLBACK_SCSV must also + be supported by the server for the prevention to work. + </p></warning> + </item> + </taglist> </section> @@ -457,12 +560,25 @@ fun(srp, Username :: string(), UserState :: term()) -> and CipherSuite is of type ciphersuite(). </item> + <tag>{alpn_preferred_protocols, [binary()]}</tag> + <item> + <p>Indicates the server will try to perform Application-Layer + Protocol Negotiation (ALPN).</p> + + <p>The list of protocols is in order of preference. The protocol + negotiated will be the first in the list that matches one of the + protocols advertised by the client. If no protocol matches, the + server will fail the connection with a "no_application_protocol" alert.</p> + + <p>The negotiated protocol can be retrieved using the <c>negotiated_protocol/1</c> function.</p> + </item> + <tag>{next_protocols_advertised, Protocols :: [binary()]}</tag> <item>The list of protocols to send to the client if the client indicates it supports the Next Protocol extension. The client may select a protocol that is not on this list. The list of protocols must not contain an empty binary. If the server negotiates a Next Protocol it can be accessed - using <c>negotiated_next_protocol/1</c> method. + using <c>negotiated_protocol/1</c> function. </item> <tag>{psk_identity, string()}</tag> @@ -518,7 +634,19 @@ fun(srp, Username :: string(), UserState :: term()) -> </p> </desc> </func> - + + <func> + <name>clear_pem_cache() -> ok </name> + <fsummary> Clears the pem cache</fsummary> + + <desc><p>PEM files, used by ssl API-functions, are cached. The + cache is regularly checked to see if any cache entries should be + invalidated, however this function provides a way to + unconditionally clear the whole cache. + </p> + </desc> + </func> + <func> <name>connect(Socket, SslOptions) -> </name> <name>connect(Socket, SslOptions, Timeout) -> {ok, SslSocket} @@ -884,31 +1012,49 @@ fun(srp, Username :: string(), UserState :: term()) -> </func> <func> - <name>versions() -> - [{SslAppVer, SupportedSslVer, AvailableSslVsn}]</name> + <name>versions() -> [versions_info()]</name> <fsummary>Returns version information relevant for the ssl application.</fsummary> <type> - <v>SslAppVer = string()</v> - <v>SupportedSslVer = [protocol()]</v> - <v>AvailableSslVsn = [protocol()]</v> + <v>versions_info() = {app_vsn, string()} | {supported | available, [protocol()] </v> </type> <desc> <p> Returns version information relevant for the - ssl application.</p> + ssl application. + </p> + <taglist> + <tag>app_vsn</tag> + <item> The application version of the OTP ssl application.</item> + + <tag>supported</tag> + + <item>TLS/SSL versions supported by default. + Overridden by a versions option on + <seealso marker="#connect-2"> connect/[2,3,4]</seealso>, <seealso + marker="#listen-2"> listen/2</seealso> and <seealso + marker="#ssl_accept-2">ssl_accept/[1,2,3]</seealso>. For the + negotiated TLS/SSL version see <seealso + marker="#connection_info-1">ssl:connection_info/1 + </seealso></item> + + <tag>available</tag> + <item>All TLS/SSL versions that the Erlang ssl application + can support. Note that TLS 1.2 requires sufficient support + from the crypto application. </item> + </taglist> </desc> </func> <func> - <name>negotiated_next_protocol(Socket) -> {ok, Protocol} | {error, next_protocol_not_negotiated}</name> - <fsummary>Returns the Next Protocol negotiated.</fsummary> + <name>negotiated_protocol(Socket) -> {ok, Protocol} | {error, protocol_not_negotiated}</name> + <fsummary>Returns the protocol negotiated through ALPN or NPN extensions.</fsummary> <type> <v>Socket = sslsocket()</v> <v>Protocol = binary()</v> </type> <desc> <p> - Returns the Next Protocol negotiated. + Returns the protocol negotiated through ALPN or NPN extensions. </p> </desc> </func> |