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1 // Copyright (c) 2017 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_BASE_NTLM_BUFFER_WRITER_H_ | |
6 #define NET_BASE_NTLM_BUFFER_WRITER_H_ | |
7 | |
8 #include <stddef.h> | |
9 #include <stdint.h> | |
10 | |
11 #include <memory> | |
12 #include <string> | |
13 | |
14 #include "base/strings/string16.h" | |
15 #include "base/strings/string_piece.h" | |
16 #include "net/base/net_export.h" | |
17 #include "net/http/ntlm_message.h" | |
18 | |
19 namespace net { | |
20 | |
21 // Supports various bounds checked low level buffer | |
22 // operations required by an NTLM implementation. | |
23 // | |
24 // The class supports sequential write to an internally | |
25 // managed buffer. All writes perform bounds checking to ensure | |
26 // enough space is remaining in the buffer. | |
27 // | |
28 // The internal buffer is allocated in the constructor with | |
29 // size |buffer_len| and owned by the class. Use | |
30 // |ReleaseBufferPtr| to take ownership of the internal | |
31 // buffer. Thereafter all operations on the class will fail. | |
32 // | |
33 // | |
34 // Write* methods write the buffer at the current cursor | |
35 // position and perform any necessary type conversion and | |
36 // provide the data in out params. After a successful write | |
37 // the cursor position is advanced past the written field. | |
38 // | |
39 // Failed writes leave the internal cursor at the same | |
40 // position as before the call. | |
41 // | |
42 // | |
43 // Based on [MS-NLMP]: NT LAN Manager (NTLM) Authentication | |
44 // Protocol specification version 28.0 [1] | |
45 // | |
46 // [1] https://msdn.microsoft.com/en-us/library/cc236621.aspx | |
47 class NET_EXPORT NtlmBufferWriter { | |
48 public: | |
49 NtlmBufferWriter(size_t buffer_len); | |
50 ~NtlmBufferWriter(); | |
51 | |
52 size_t GetLength() const { return buffer_len_; } | |
53 size_t GetCursor() const { return cursor_; } | |
54 bool IsEndOfBuffer() const { return cursor_ >= GetLength(); } | |
55 uint8_t* GetBufferPtr() const { return buffer_.get(); } | |
56 | |
57 // Releases ownership of the internal buffer. Subsequent writes | |
58 // will all fail. | |
59 uint8_t* ReleaseBufferPtr() { | |
60 buffer_len_ = 0; | |
61 cursor_ = 0; | |
62 return buffer_.release(); | |
63 } | |
64 | |
65 base::StringPiece GetBuffer() const { | |
66 return base::StringPiece(reinterpret_cast<const char*>(buffer_.get()), | |
67 buffer_len_); | |
68 } | |
69 | |
70 // Returns true if there are |len| more bytes between the | |
71 // current cursor position and the end of the buffer. | |
72 bool CanWrite(size_t len) const; | |
73 | |
74 bool WriteUInt16(uint16_t value); | |
75 bool WriteUInt32(uint32_t value); | |
76 bool WriteUInt64(uint64_t value); | |
77 bool WriteBytes(const uint8_t* buffer, size_t len); | |
78 | |
79 bool WriteZeros(size_t count); | |
80 | |
81 // A security buffer is an 8 byte structure that defines the | |
82 // offset and length of a payload (string, struct or byte array) | |
83 // that appears after the fixed part of the message. | |
84 // | |
85 // The structure is (little endian fields): | |
86 // uint16 - |length| Length of payload | |
87 // uint16 - Allocation (always set to |length|) | |
88 // uint32 - |offset| Offset from start of message | |
89 bool WriteSecurityBuffer(uint16_t length, uint32_t offset); | |
90 bool WriteEmptySecurityBuffer(); | |
91 | |
92 // Writes a string of 8 bit characters to the buffer. | |
93 bool WriteNarrowString(const std::string& str); | |
94 | |
95 // Converts the 16 bit characters to UTF8 and writes | |
96 // the resulting 8 bit characters. | |
97 bool WriteString16AsUTF8(const base::string16& str); | |
98 | |
99 // Zero pads an 8 bit string to a 16 bit string and writes | |
100 // the resulting 16 bit characters. | |
Ryan Sleevi
2017/05/30 19:02:23
This comment I found a bit confusing. Could you de
zentaro
2017/06/05 17:28:44
I tried to clarify. In practice I think nothing ev
| |
101 bool WriteNarrowStringAsString16(const std::string& str); | |
102 | |
103 // Writes the 16 bit characters to the buffer. | |
104 bool WriteUnicodeString(const base::string16& str); | |
105 | |
106 // Writes the 8 byte NTLM signature "NTLMSSP\0" into the buffer. | |
107 bool WriteSignature(); | |
108 | |
109 // There are 3 message types Negotiate (sent by client), | |
110 // Challenge (sent by server), and Authenticate (sent by client). | |
111 // | |
112 // This writes |message_type| as a uint32_t into the buffer. | |
113 bool WriteMessageType(NtlmMessage::MessageType message_type); | |
114 | |
115 // Performs |WriteSignature| then |WriteMessageType|. | |
116 bool WriteMessageHeader(NtlmMessage::MessageType message_type); | |
117 | |
118 static size_t GetStringPayloadLength(const base::string16& str, | |
119 bool is_unicode); | |
120 static size_t GetStringPayloadLength(const std::string& str, bool is_unicode); | |
121 | |
122 private: | |
123 // Writes |sizeof(T)| bytes little-endian of an integer type to | |
124 // the buffer. | |
125 template <typename T> | |
126 bool WriteUInt(T value); | |
127 bool SetCursor(size_t cursor); | |
128 bool WriteUnicodeStringIntoBuffer(const base::string16& value, | |
129 uint8_t* buffer, | |
130 size_t buffer_len); | |
131 | |
132 std::unique_ptr<uint8_t[]> buffer_; | |
133 size_t buffer_len_; | |
134 size_t cursor_; | |
135 | |
136 DISALLOW_COPY_AND_ASSIGN(NtlmBufferWriter); | |
137 }; | |
138 | |
139 } // namespace net | |
140 | |
141 #endif // NET_BASE_NTLM_BUFFER_WRITER_H_ | |
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