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      */
46     explicit Interface(const std::vector<uint8_t>& k2) : k2(k2)
47     {
48     }
49 
50     Interface() = delete;
51     virtual ~Interface() = default;
52     Interface(const Interface&) = default;
53     Interface& operator=(const Interface&) = default;
54     Interface(Interface&&) = default;
55     Interface& operator=(Interface&&) = default;
56 
57     /**
58      * @brief Decrypt the incoming payload
59      *
60      * @param[in] packet - Incoming IPMI packet
61      * @param[in] sessHeaderLen - Length of the IPMI Session Header
62      * @param[in] payloadLen - Length of the encrypted IPMI payload
63      *
64      * @return decrypted payload if the operation is successful
65      */
66     virtual std::vector<uint8_t>
67         decryptPayload(const std::vector<uint8_t>& packet,
68                        const size_t sessHeaderLen,
69                        const size_t payloadLen) const = 0;
70 
71     /**
72      * @brief Encrypt the outgoing payload
73      *
74      * @param[in] payload - plain payload for the outgoing IPMI packet
75      *
76      * @return encrypted payload if the operation is successful
77      *
78      */
79     virtual std::vector<uint8_t>
80         encryptPayload(std::vector<uint8_t>& payload) const = 0;
81 
82     /**
83      * @brief Check if the Confidentiality algorithm is supported
84      *
85      * @param[in] algo - confidentiality algorithm
86      *
87      * @return true if algorithm is supported else false
88      *
89      */
90     static bool isAlgorithmSupported(Algorithms algo)
91     {
92         if (algo == Algorithms::AES_CBC_128)
93         {
94             return true;
95         }
96         else
97         {
98             return false;
99         }
100     }
101 
102   protected:
103     /**
104      * @brief The Cipher Key is the first 128-bits of key “K2”, K2 is
105      * generated by processing a pre-defined constant keyed by Session
106      * Integrity Key (SIK) that was created during session activation.
107      */
108     std::vector<uint8_t> k2;
109 };
110 
111 /**
112  * @class AlgoAES128
113  *
114  * @brief Implementation of the AES-CBC-128 Confidentiality algorithm
115  *
116  * AES-128 uses a 128-bit Cipher Key. The Cipher Key is the first 128-bits of
117  * key “K2”.Once the Cipher Key has been generated it is used to encrypt
118  * the payload data. The payload data is padded to make it an integral numbers
119  * of blocks in length (a block is 16 bytes for AES). The payload is then
120  * encrypted one block at a time from the lowest data offset to the highest
121  * using Cipher_Key as specified in AES.
122  */
123 class AlgoAES128 final : public Interface
124 {
125   public:
126     static constexpr size_t AESCBC128ConfHeader = 16;
127     static constexpr size_t AESCBC128BlockSize = 16;
128 
129     /**
130      * If confidentiality bytes are present, the value of the first byte is
131      * one (01h). and all subsequent bytes shall have a monotonically
132      * increasing value (e.g., 02h, 03h, 04h, etc). The receiver, as an
133      * additional check for proper decryption, shall check the value of each
134      * byte of Confidentiality Pad. For AES algorithm, the pad bytes will
135      * range from 0 to 15 bytes. This predefined array would help in
136      * doing the additional check.
137      */
138     static constexpr std::array<uint8_t, AESCBC128BlockSize - 1> confPadBytes =
139         {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
140          0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F};
141 
142     /**
143      * @brief Constructor for AlgoAES128
144      *
145      * @param[in] - Session Integrity key
146      */
147     explicit AlgoAES128(const std::vector<uint8_t>& k2) : Interface(k2)
148     {
149     }
150 
151     AlgoAES128() = delete;
152     ~AlgoAES128() = default;
153     AlgoAES128(const AlgoAES128&) = default;
154     AlgoAES128& operator=(const AlgoAES128&) = default;
155     AlgoAES128(AlgoAES128&&) = default;
156     AlgoAES128& operator=(AlgoAES128&&) = default;
157 
158     /**
159      * @brief Decrypt the incoming payload
160      *
161      * @param[in] packet - Incoming IPMI packet
162      * @param[in] sessHeaderLen - Length of the IPMI Session Header
163      * @param[in] payloadLen - Length of the encrypted IPMI payload
164      *
165      * @return decrypted payload if the operation is successful
166      */
167     std::vector<uint8_t> decryptPayload(const std::vector<uint8_t>& packet,
168                                         const size_t sessHeaderLen,
169                                         const size_t payloadLen) const override;
170 
171     /**
172      * @brief Encrypt the outgoing payload
173      *
174      * @param[in] payload - plain payload for the outgoing IPMI packet
175      *
176      * @return encrypted payload if the operation is successful
177      *
178      */
179     std::vector<uint8_t>
180         encryptPayload(std::vector<uint8_t>& payload) const override;
181 
182   private:
183     /**
184      * @brief Decrypt the passed data
185      *
186      * @param[in] iv - Initialization vector
187      * @param[in] input - Pointer to input data
188      * @param[in] inputLen - Length of input data
189      *
190      * @return decrypted data if the operation is successful
191      */
192     std::vector<uint8_t> decryptData(const uint8_t* iv, const uint8_t* input,
193                                      const int inputLen) const;
194 
195     /**
196      * @brief Encrypt the passed data
197      *
198      * @param[in] input - Pointer to input data
199      * @param[in] inputLen - Length of input data
200      *
201      * @return encrypted data if the operation is successful
202      */
203     std::vector<uint8_t> encryptData(const uint8_t* input,
204                                      const int inputLen) const;
205 };
206 
207 } // namespace crypt
208 
209 } // namespace cipher
210