Botan 2.19.2
Crypto and TLS for C&
stream_cipher.h
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1/*
2* Stream Cipher
3* (C) 1999-2007 Jack Lloyd
4*
5* Botan is released under the Simplified BSD License (see license.txt)
6*/
7
8#ifndef BOTAN_STREAM_CIPHER_H_
9#define BOTAN_STREAM_CIPHER_H_
10
11#include <botan/sym_algo.h>
12#include <string>
13#include <memory>
14#include <vector>
15
16namespace Botan {
17
18/**
19* Base class for all stream ciphers
20*/
22 {
23 public:
24 virtual ~StreamCipher() = default;
25
26 /**
27 * Create an instance based on a name
28 * If provider is empty then best available is chosen.
29 * @param algo_spec algorithm name
30 * @param provider provider implementation to use
31 * @return a null pointer if the algo/provider combination cannot be found
32 */
33 static std::unique_ptr<StreamCipher>
34 create(const std::string& algo_spec,
35 const std::string& provider = "");
36
37 /**
38 * Create an instance based on a name
39 * If provider is empty then best available is chosen.
40 * @param algo_spec algorithm name
41 * @param provider provider implementation to use
42 * Throws a Lookup_Error if the algo/provider combination cannot be found
43 */
44 static std::unique_ptr<StreamCipher>
45 create_or_throw(const std::string& algo_spec,
46 const std::string& provider = "");
47
48 /**
49 * @return list of available providers for this algorithm, empty if not available
50 */
51 static std::vector<std::string> providers(const std::string& algo_spec);
52
53 /**
54 * Encrypt or decrypt a message
55 * @param in the plaintext
56 * @param out the byte array to hold the output, i.e. the ciphertext
57 * @param len the length of both in and out in bytes
58 */
59 virtual void cipher(const uint8_t in[], uint8_t out[], size_t len) = 0;
60
61 /**
62 * Write keystream bytes to a buffer
63 * @param out the byte array to hold the keystream
64 * @param len the length of out in bytes
65 */
66 virtual void write_keystream(uint8_t out[], size_t len)
67 {
68 clear_mem(out, len);
69 cipher1(out, len);
70 }
71
72 /**
73 * Encrypt or decrypt a message
74 * The message is encrypted/decrypted in place.
75 * @param buf the plaintext / ciphertext
76 * @param len the length of buf in bytes
77 */
78 void cipher1(uint8_t buf[], size_t len)
79 { cipher(buf, buf, len); }
80
81 /**
82 * Encrypt a message
83 * The message is encrypted/decrypted in place.
84 * @param inout the plaintext / ciphertext
85 */
86 template<typename Alloc>
87 void encipher(std::vector<uint8_t, Alloc>& inout)
88 { cipher(inout.data(), inout.data(), inout.size()); }
89
90 /**
91 * Encrypt a message
92 * The message is encrypted in place.
93 * @param inout the plaintext / ciphertext
94 */
95 template<typename Alloc>
96 void encrypt(std::vector<uint8_t, Alloc>& inout)
97 { cipher(inout.data(), inout.data(), inout.size()); }
98
99 /**
100 * Decrypt a message in place
101 * The message is decrypted in place.
102 * @param inout the plaintext / ciphertext
103 */
104 template<typename Alloc>
105 void decrypt(std::vector<uint8_t, Alloc>& inout)
106 { cipher(inout.data(), inout.data(), inout.size()); }
107
108 /**
109 * Resync the cipher using the IV
110 * @param iv the initialization vector
111 * @param iv_len the length of the IV in bytes
112 */
113 virtual void set_iv(const uint8_t iv[], size_t iv_len) = 0;
114
115 /**
116 * Return the default (preferred) nonce length
117 * If this function returns 0, then this cipher does not support nonces
118 */
119 virtual size_t default_iv_length() const { return 0; }
120
121 /**
122 * @param iv_len the length of the IV in bytes
123 * @return if the length is valid for this algorithm
124 */
125 virtual bool valid_iv_length(size_t iv_len) const { return (iv_len == 0); }
126
127 /**
128 * @return a new object representing the same algorithm as *this
129 */
130 virtual StreamCipher* clone() const = 0;
131
132 /**
133 * Set the offset and the state used later to generate the keystream
134 * @param offset the offset where we begin to generate the keystream
135 */
136 virtual void seek(uint64_t offset) = 0;
137
138 /**
139 * @return provider information about this implementation. Default is "base",
140 * might also return "sse2", "avx2", "openssl", or some other arbitrary string.
141 */
142 virtual std::string provider() const { return "base"; }
143 };
144
145}
146
147#endif
void cipher1(uint8_t buf[], size_t len)
Definition: stream_cipher.h:78
void decrypt(std::vector< uint8_t, Alloc > &inout)
virtual void cipher(const uint8_t in[], uint8_t out[], size_t len)=0
virtual size_t default_iv_length() const
virtual ~StreamCipher()=default
void encipher(std::vector< uint8_t, Alloc > &inout)
Definition: stream_cipher.h:87
virtual StreamCipher * clone() const =0
virtual void set_iv(const uint8_t iv[], size_t iv_len)=0
virtual void write_keystream(uint8_t out[], size_t len)
Definition: stream_cipher.h:66
void encrypt(std::vector< uint8_t, Alloc > &inout)
Definition: stream_cipher.h:96
virtual void seek(uint64_t offset)=0
virtual bool valid_iv_length(size_t iv_len) const
virtual std::string provider() const
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:31
Definition: alg_id.cpp:13
void clear_mem(T *ptr, size_t n)
Definition: mem_ops.h:115