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