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1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef NET_SSL_SSL_CONFIG_H_
6 #define NET_SSL_SSL_CONFIG_H_
7 
8 #include "base/basictypes.h"
9 #include "base/memory/ref_counted.h"
10 #include "net/base/net_export.h"
11 #include "net/cert/x509_certificate.h"
12 
13 namespace net {
14 
15 // Various TLS/SSL ProtocolVersion values encoded as uint16
16 //      struct {
17 //          uint8 major;
18 //          uint8 minor;
19 //      } ProtocolVersion;
20 // The most significant byte is |major|, and the least significant byte
21 // is |minor|.
22 enum {
23   SSL_PROTOCOL_VERSION_SSL3 = 0x0300,
24   SSL_PROTOCOL_VERSION_TLS1 = 0x0301,
25   SSL_PROTOCOL_VERSION_TLS1_1 = 0x0302,
26   SSL_PROTOCOL_VERSION_TLS1_2 = 0x0303,
27 };
28 
29 // Default minimum protocol version.
30 NET_EXPORT extern const uint16 kDefaultSSLVersionMin;
31 
32 // Default maximum protocol version.
33 NET_EXPORT extern const uint16 kDefaultSSLVersionMax;
34 
35 // Default minimum protocol version that it's acceptable to fallback to.
36 NET_EXPORT extern const uint16 kDefaultSSLVersionFallbackMin;
37 
38 // A collection of SSL-related configuration settings.
39 struct NET_EXPORT SSLConfig {
40   // Default to revocation checking.
41   // Default to SSL 3.0 ~ default_version_max() on.
42   SSLConfig();
43   ~SSLConfig();
44 
45   // Returns true if |cert| is one of the certs in |allowed_bad_certs|.
46   // The expected cert status is written to |cert_status|. |*cert_status| can
47   // be NULL if user doesn't care about the cert status.
48   bool IsAllowedBadCert(X509Certificate* cert, CertStatus* cert_status) const;
49 
50   // Same as above except works with DER encoded certificates instead
51   // of X509Certificate.
52   bool IsAllowedBadCert(const base::StringPiece& der_cert,
53                         CertStatus* cert_status) const;
54 
55   // rev_checking_enabled is true if online certificate revocation checking is
56   // enabled (i.e. OCSP and CRL fetching).
57   //
58   // Regardless of this flag, CRLSet checking is always enabled and locally
59   // cached revocation information will be considered.
60   bool rev_checking_enabled;
61 
62   // rev_checking_required_local_anchors is true if revocation checking is
63   // required to succeed when certificates chain to local trust anchors (that
64   // is, non-public CAs). If revocation information cannot be obtained, such
65   // certificates will be treated as revoked ("hard-fail").
66   // Note: This is distinct from rev_checking_enabled. If true, it is
67   // equivalent to also setting rev_checking_enabled, but only when the
68   // certificate chain chains to a local (non-public) trust anchor.
69   bool rev_checking_required_local_anchors;
70 
71   // The minimum and maximum protocol versions that are enabled.
72   // SSL 3.0 is 0x0300, TLS 1.0 is 0x0301, TLS 1.1 is 0x0302, and so on.
73   // (Use the SSL_PROTOCOL_VERSION_xxx enumerators defined above.)
74   // SSL 2.0 is not supported. If version_max < version_min, it means no
75   // protocol versions are enabled.
76   uint16 version_min;
77   uint16 version_max;
78 
79   // version_fallback_min contains the minimum version that is acceptable to
80   // fallback to. Versions before this may be tried to see whether they would
81   // have succeeded and thus to give a better message to the user, but the
82   // resulting connection won't be used in these cases.
83   uint16 version_fallback_min;
84 
85   // Presorted list of cipher suites which should be explicitly prevented from
86   // being used in addition to those disabled by the net built-in policy.
87   //
88   // By default, all cipher suites supported by the underlying SSL
89   // implementation will be enabled except for:
90   // - Null encryption cipher suites.
91   // - Weak cipher suites: < 80 bits of security strength.
92   // - FORTEZZA cipher suites (obsolete).
93   // - IDEA cipher suites (RFC 5469 explains why).
94   // - Anonymous cipher suites.
95   // - ECDSA cipher suites on platforms that do not support ECDSA signed
96   //   certificates, as servers may use the presence of such ciphersuites as a
97   //   hint to send an ECDSA certificate.
98   // The ciphers listed in |disabled_cipher_suites| will be removed in addition
99   // to the above list.
100   //
101   // Though cipher suites are sent in TLS as "uint8 CipherSuite[2]", in
102   // big-endian form, they should be declared in host byte order, with the
103   // first uint8 occupying the most significant byte.
104   // Ex: To disable TLS_RSA_WITH_RC4_128_MD5, specify 0x0004, while to
105   // disable TLS_ECDH_ECDSA_WITH_RC4_128_SHA, specify 0xC002.
106   std::vector<uint16> disabled_cipher_suites;
107 
108   bool channel_id_enabled;   // True if TLS channel ID extension is enabled.
109   bool false_start_enabled;  // True if we'll use TLS False Start.
110   // True if the Certificate Transparency signed_certificate_timestamp
111   // TLS extension is enabled.
112   bool signed_cert_timestamps_enabled;
113 
114   // require_forward_secrecy, if true, causes only (EC)DHE cipher suites to be
115   // enabled. NOTE: this only applies to server sockets currently, although
116   // that could be extended if needed.
117   bool require_forward_secrecy;
118 
119   // TODO(wtc): move the following members to a new SSLParams structure.  They
120   // are not SSL configuration settings.
121 
122   struct NET_EXPORT CertAndStatus {
123     CertAndStatus();
124     ~CertAndStatus();
125 
126     std::string der_cert;
127     CertStatus cert_status;
128   };
129 
130   // Add any known-bad SSL certificate (with its cert status) to
131   // |allowed_bad_certs| that should not trigger an ERR_CERT_* error when
132   // calling SSLClientSocket::Connect.  This would normally be done in
133   // response to the user explicitly accepting the bad certificate.
134   std::vector<CertAndStatus> allowed_bad_certs;
135 
136   // True if we should send client_cert to the server.
137   bool send_client_cert;
138 
139   bool verify_ev_cert;  // True if we should verify the certificate for EV.
140 
141   bool version_fallback;  // True if we are falling back to an older protocol
142                           // version (one still needs to decrement
143                           // version_max).
144 
145   // If cert_io_enabled is false, then certificate verification will not
146   // result in additional HTTP requests. (For example: to fetch missing
147   // intermediates or to perform OCSP/CRL fetches.) It also implies that online
148   // revocation checking is disabled.
149   // NOTE: Only used by NSS.
150   bool cert_io_enabled;
151 
152   // The list of application level protocols supported. If set, this will
153   // enable Next Protocol Negotiation (if supported). The order of the
154   // protocols doesn't matter expect for one case: if the server supports Next
155   // Protocol Negotiation, but there is no overlap between the server's and
156   // client's protocol sets, then the first protocol in this list will be
157   // requested by the client.
158   std::vector<std::string> next_protos;
159 
160   scoped_refptr<X509Certificate> client_cert;
161 };
162 
163 }  // namespace net
164 
165 #endif  // NET_SSL_SSL_CONFIG_H_
166