1 #pragma once
2 
3 #include <array>
4 #include <cstddef>
5 #include <cstdint>
6 #include <vector>
7 
8 namespace cipher
9 {
10 
11 namespace crypt
12 {
13 
14 /**
15  * @enum Confidentiality Algorithms
16  *
17  * The Confidentiality Algorithm Number specifies the encryption/decryption
18  * algorithm field that is used for encrypted payload data under the session.
19  * The ‘encrypted’ bit in the payload type field being set identifies packets
20  * with payloads that include data that is encrypted per this specification.
21  * When payload data is encrypted, there may be additional “Confidentiality
22  * Header” and/or “Confidentiality Trailer” fields that are included within the
23  * payload. The size and definition of those fields is specific to the
24  * particular confidentiality algorithm. Based on security recommendations
25  * encrypting IPMI traffic is preferred, so NONE is not supported.
26  */
27 enum class Algorithms : uint8_t
28 {
29     NONE,        /**< No encryption (mandatory , not supported) */
30     AES_CBC_128, /**< AES-CBC-128 Algorithm (mandatory option) */
31     xRC4_128,    /**< xRC4-128 Algorithm (optional option) */
32     xRC4_40,     /**< xRC4-40 Algorithm (optional option) */
33 };
34 
35 /**
36  * @class Interface
37  *
38  * Interface is the base class for the Confidentiality Algorithms.
39  */
40 class Interface
41 {
42   public:
43     /**
44      * @brief Constructor for Interface
45      */
Interface(const std::vector<uint8_t> & k2)46     explicit Interface(const std::vector<uint8_t>& k2) : k2(k2) {}
47 
48     Interface() = delete;
49     virtual ~Interface() = default;
50     Interface(const Interface&) = default;
51     Interface& operator=(const Interface&) = default;
52     Interface(Interface&&) = default;
53     Interface& operator=(Interface&&) = default;
54 
55     /**
56      * @brief Decrypt the incoming payload
57      *
58      * @param[in] packet - Incoming IPMI packet
59      * @param[in] sessHeaderLen - Length of the IPMI Session Header
60      * @param[in] payloadLen - Length of the encrypted IPMI payload
61      *
62      * @return decrypted payload if the operation is successful
63      */
64     virtual std::vector<uint8_t> decryptPayload(
65         const std::vector<uint8_t>& packet, const size_t sessHeaderLen,
66         const size_t payloadLen) const = 0;
67 
68     /**
69      * @brief Encrypt the outgoing payload
70      *
71      * @param[in] payload - plain payload for the outgoing IPMI packet
72      *
73      * @return encrypted payload if the operation is successful
74      *
75      */
76     virtual std::vector<uint8_t>
77         encryptPayload(std::vector<uint8_t>& payload) const = 0;
78 
79     /**
80      * @brief Check if the Confidentiality algorithm is supported
81      *
82      * @param[in] algo - confidentiality algorithm
83      *
84      * @return true if algorithm is supported else false
85      *
86      */
isAlgorithmSupported(Algorithms algo)87     static bool isAlgorithmSupported(Algorithms algo)
88     {
89         if (algo == Algorithms::AES_CBC_128)
90         {
91             return true;
92         }
93         else
94         {
95             return false;
96         }
97     }
98 
99   protected:
100     /**
101      * @brief The Cipher Key is the first 128-bits of key “K2”, K2 is
102      * generated by processing a pre-defined constant keyed by Session
103      * Integrity Key (SIK) that was created during session activation.
104      */
105     std::vector<uint8_t> k2;
106 };
107 
108 /**
109  * @class AlgoAES128
110  *
111  * @brief Implementation of the AES-CBC-128 Confidentiality algorithm
112  *
113  * AES-128 uses a 128-bit Cipher Key. The Cipher Key is the first 128-bits of
114  * key “K2”.Once the Cipher Key has been generated it is used to encrypt
115  * the payload data. The payload data is padded to make it an integral numbers
116  * of blocks in length (a block is 16 bytes for AES). The payload is then
117  * encrypted one block at a time from the lowest data offset to the highest
118  * using Cipher_Key as specified in AES.
119  */
120 class AlgoAES128 final : public Interface
121 {
122   public:
123     static constexpr size_t AESCBC128ConfHeader = 16;
124     static constexpr size_t AESCBC128BlockSize = 16;
125 
126     /**
127      * If confidentiality bytes are present, the value of the first byte is
128      * one (01h). and all subsequent bytes shall have a monotonically
129      * increasing value (e.g., 02h, 03h, 04h, etc). The receiver, as an
130      * additional check for proper decryption, shall check the value of each
131      * byte of Confidentiality Pad. For AES algorithm, the pad bytes will
132      * range from 0 to 15 bytes. This predefined array would help in
133      * doing the additional check.
134      */
135     static constexpr std::array<uint8_t, AESCBC128BlockSize - 1> confPadBytes =
136         {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
137          0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F};
138 
139     /**
140      * @brief Constructor for AlgoAES128
141      *
142      * @param[in] - Session Integrity key
143      */
AlgoAES128(const std::vector<uint8_t> & k2)144     explicit AlgoAES128(const std::vector<uint8_t>& k2) : Interface(k2) {}
145 
146     AlgoAES128() = delete;
147     ~AlgoAES128() = default;
148     AlgoAES128(const AlgoAES128&) = default;
149     AlgoAES128& operator=(const AlgoAES128&) = default;
150     AlgoAES128(AlgoAES128&&) = default;
151     AlgoAES128& operator=(AlgoAES128&&) = default;
152 
153     /**
154      * @brief Decrypt the incoming payload
155      *
156      * @param[in] packet - Incoming IPMI packet
157      * @param[in] sessHeaderLen - Length of the IPMI Session Header
158      * @param[in] payloadLen - Length of the encrypted IPMI payload
159      *
160      * @return decrypted payload if the operation is successful
161      */
162     std::vector<uint8_t> decryptPayload(const std::vector<uint8_t>& packet,
163                                         const size_t sessHeaderLen,
164                                         const size_t payloadLen) const override;
165 
166     /**
167      * @brief Encrypt the outgoing payload
168      *
169      * @param[in] payload - plain payload for the outgoing IPMI packet
170      *
171      * @return encrypted payload if the operation is successful
172      *
173      */
174     std::vector<uint8_t>
175         encryptPayload(std::vector<uint8_t>& payload) const override;
176 
177   private:
178     /**
179      * @brief Decrypt the passed data
180      *
181      * @param[in] iv - Initialization vector
182      * @param[in] input - Pointer to input data
183      * @param[in] inputLen - Length of input data
184      *
185      * @return decrypted data if the operation is successful
186      */
187     std::vector<uint8_t> decryptData(const uint8_t* iv, const uint8_t* input,
188                                      const int inputLen) const;
189 
190     /**
191      * @brief Encrypt the passed data
192      *
193      * @param[in] input - Pointer to input data
194      * @param[in] inputLen - Length of input data
195      *
196      * @return encrypted data if the operation is successful
197      */
198     std::vector<uint8_t> encryptData(const uint8_t* input,
199                                      const int inputLen) const;
200 };
201 
202 } // namespace crypt
203 
204 } // namespace cipher
205