2 * Copyright (C) 1996-2017 The Squid Software Foundation and contributors
4 * Squid software is distributed under GPLv2+ license and includes
5 * contributions from numerous individuals and organizations.
6 * Please see the COPYING and CONTRIBUTORS files for details.
9 #ifndef SQUID_SSL_BIO_H
10 #define SQUID_SSL_BIO_H
12 #include "FadingCounter.h"
14 #include "security/Handshake.h"
18 #if HAVE_OPENSSL_BIO_H
19 #include <openssl/bio.h>
22 #include <type_traits>
27 /// BIO source and sink node, handling socket I/O and monitoring SSL state
36 explicit Bio(const int anFd
);
39 /// Writes the given data to socket
40 virtual int write(const char *buf
, int size
, BIO
*table
);
42 /// Reads data from socket
43 virtual int read(char *buf
, int size
, BIO
*table
);
45 /// Flushes any buffered data to socket.
46 /// The Ssl::Bio does not buffer any data, so this method has nothing to do
47 virtual void flush(BIO
*table
) {}
49 int fd() const { return fd_
; } ///< The SSL socket descriptor
51 /// Called by linked SSL connection whenever state changes, an alert
52 /// appears, or an error occurs. See SSL_set_info_callback().
53 virtual void stateChanged(const SSL
*ssl
, int where
, int ret
);
55 /// Creates a low-level BIO table, creates a high-level Ssl::Bio object
56 /// for a given socket, and then links the two together via BIO_C_SET_FD.
57 static BIO
*Create(const int fd
, Type type
);
58 /// Tells ssl connection to use BIO and monitor state via stateChanged()
59 static void Link(SSL
*ssl
, BIO
*bio
);
61 const SBuf
&rBufData() {return rbuf
;} ///< The buffered input data
63 const int fd_
; ///< the SSL socket we are reading and writing
64 SBuf rbuf
; ///< Used to buffer input data.
67 /// BIO node to handle socket IO for squid client side
68 /// If bumping is enabled this Bio detects and analyses client hello message
69 /// to retrieve the SSL features supported by the client
70 class ClientBio
: public Bio
73 explicit ClientBio(const int anFd
);
75 /// The ClientBio version of the Ssl::Bio::stateChanged method
76 /// When the client hello message retrieved, fill the
77 /// "features" member with the client provided informations.
78 virtual void stateChanged(const SSL
*ssl
, int where
, int ret
);
79 /// The ClientBio version of the Ssl::Bio::write method
80 virtual int write(const char *buf
, int size
, BIO
*table
);
81 /// The ClientBio version of the Ssl::Bio::read method
82 /// If the holdRead flag is true then it does not write any data
83 /// to socket and sets the "read retry" flag of the BIO to true
84 virtual int read(char *buf
, int size
, BIO
*table
);
85 /// Prevents or allow writting on socket.
86 void hold(bool h
) {holdRead_
= holdWrite_
= h
;}
88 /// Sets the buffered input data (Bio::rbuf).
89 /// Used to pass payload data (normally client HELLO data) retrieved
91 void setReadBufData(SBuf
&data
) {rbuf
= data
;}
93 /// approximate size of a time window for computing client-initiated renegotiation rate (in seconds)
94 static const time_t RenegotiationsWindow
= 10;
96 /// the maximum tolerated number of client-initiated renegotiations in RenegotiationsWindow
97 static const int RenegotiationsLimit
= 5;
99 bool holdRead_
; ///< The read hold state of the bio.
100 bool holdWrite_
; ///< The write hold state of the bio.
101 int helloSize
; ///< The SSL hello message sent by client size
102 FadingCounter renegotiations
; ///< client requested renegotiations limit control
104 /// why we should terminate the connection during next TLS operation (or nil)
105 const char *abortReason
;
108 /// BIO node to handle socket IO for squid server side
109 /// If bumping is enabled, analyses the SSL hello message sent by squid OpenSSL
110 /// subsystem (step3 bumping step) against bumping mode:
111 /// * Peek mode: Send client hello message instead of the openSSL generated
112 /// hello message and normaly denies bumping and allow only
113 /// splice or terminate the SSL connection
114 /// * Stare mode: Sends the openSSL generated hello message and normaly
115 /// denies splicing and allow bump or terminate the SSL
117 /// If SQUID_USE_OPENSSL_HELLO_OVERWRITE_HACK is enabled also checks if the
118 /// openSSL library features are compatible with the features reported in
119 /// web client SSL hello message and if it is, overwrites the openSSL SSL
120 /// object members to replace hello message with web client hello message.
121 /// This is may allow bumping in peek mode and splicing in stare mode after
122 /// the server hello message received.
123 class ServerBio
: public Bio
126 explicit ServerBio(const int anFd
);
128 /// The ServerBio version of the Ssl::Bio::stateChanged method
129 virtual void stateChanged(const SSL
*ssl
, int where
, int ret
);
130 /// The ServerBio version of the Ssl::Bio::write method
131 /// If a clientRandom number is set then rewrites the raw hello message
132 /// "client random" field with the provided random number.
133 /// It may buffer the output packets.
134 virtual int write(const char *buf
, int size
, BIO
*table
);
135 /// The ServerBio version of the Ssl::Bio::read method
136 /// If the record flag is set then append the data to the rbuf member
137 virtual int read(char *buf
, int size
, BIO
*table
);
138 /// The ServerBio version of the Ssl::Bio::flush method.
139 /// Flushes any buffered data
140 virtual void flush(BIO
*table
);
141 /// Sets the random number to use in client SSL HELLO message
142 void setClientFeatures(Security::TlsDetails::Pointer
const &details
, SBuf
const &hello
);
144 bool resumingSession();
146 /// The write hold state
147 bool holdWrite() const {return holdWrite_
;}
148 /// Enables or disables the write hold state
149 void holdWrite(bool h
) {holdWrite_
= h
;}
150 /// The read hold state
151 bool holdRead() const {return holdRead_
;}
152 /// Enables or disables the read hold state
153 void holdRead(bool h
) {holdRead_
= h
;}
154 /// Enables or disables the input data recording, for internal analysis.
155 void recordInput(bool r
) {record_
= r
;}
156 /// Whether we can splice or not the SSL stream
157 bool canSplice() {return allowSplice
;}
158 /// Whether we can bump or not the SSL stream
159 bool canBump() {return allowBump
;}
161 void mode(Ssl::BumpMode m
) {bumpMode_
= m
;}
162 Ssl::BumpMode
bumpMode() {return bumpMode_
;} ///< return the bumping mode
164 /// \retval true if the Server hello message received
165 bool gotHello() const { return (parsedHandshake
&& !parseError
); }
167 /// Return true if the Server Hello parsing failed
168 bool gotHelloFailed() const { return (parsedHandshake
&& parseError
); }
170 /// \return the server certificates list if received and parsed correctly
171 const Security::CertList
&serverCertificatesIfAny() { return parser_
.serverCertificates
; }
173 /// \return the TLS Details advertised by TLS server.
174 const Security::TlsDetails::Pointer
&receivedHelloDetails() const {return parser_
.details
;}
177 int readAndGive(char *buf
, const int size
, BIO
*table
);
178 int readAndParse(char *buf
, const int size
, BIO
*table
);
179 int readAndBuffer(BIO
*table
);
180 int giveBuffered(char *buf
, const int size
);
182 /// SSL client features extracted from ClientHello message or SSL object
183 Security::TlsDetails::Pointer clientTlsDetails
;
184 /// TLS client hello message, used to adapt our tls Hello message to the server
185 SBuf clientHelloMessage
;
186 SBuf helloMsg
; ///< Used to buffer output data.
187 mb_size_t helloMsgSize
;
188 bool helloBuild
; ///< True if the client hello message sent to the server
189 bool allowSplice
; ///< True if the SSL stream can be spliced
190 bool allowBump
; ///< True if the SSL stream can be bumped
191 bool holdWrite_
; ///< The write hold state of the bio.
192 bool holdRead_
; ///< The read hold state of the bio.
193 bool record_
; ///< If true the input data recorded to rbuf for internal use
194 bool parsedHandshake
; ///< whether we are done parsing TLS Hello
195 bool parseError
; ///< error while parsing server hello message
196 Ssl::BumpMode bumpMode_
;
198 /// The size of data stored in rbuf which passed to the openSSL
199 size_t rbufConsumePos
;
200 Security::HandshakeParser parser_
; ///< The TLS/SSL messages parser.
206 applyTlsDetailsToSSL(SSL
*ssl
, Security::TlsDetails::Pointer
const &details
, Ssl::BumpMode bumpMode
);
208 #if (OPENSSL_VERSION_NUMBER < 0x10100000L)
209 // OpenSSL v1.0 bio compatibility functions
210 inline void *BIO_get_data(BIO
*table
) { return table
->ptr
; }
211 inline void BIO_set_data(BIO
*table
, void *data
) { table
->ptr
= data
; }
212 inline int BIO_get_init(BIO
*table
) { return table
->init
; }
213 inline void BIO_set_init(BIO
*table
, int init
) { table
->init
= init
; }
216 #endif /* SQUID_SSL_BIO_H */