aboutsummaryrefslogtreecommitdiffstats
path: root/src/lib/ffi/ffi_cipher.cpp
blob: 6bb45dec8c3bb887508ad1931be467ae13d32c63 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*
* (C) 2015,2017 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/ffi.h>
#include <botan/internal/ffi_util.h>
#include <botan/aead.h>

extern "C" {

using namespace Botan_FFI;

struct botan_cipher_struct : public botan_struct<Botan::Cipher_Mode, 0xB4A2BF9C>
   {
   explicit botan_cipher_struct(Botan::Cipher_Mode* x) : botan_struct(x) {}
   Botan::secure_vector<uint8_t> m_buf;
   };

int botan_cipher_init(botan_cipher_t* cipher, const char* cipher_name, uint32_t flags)
   {
   return ffi_guard_thunk(BOTAN_CURRENT_FUNCTION, [=]() {
      const bool encrypt_p = ((flags & BOTAN_CIPHER_INIT_FLAG_MASK_DIRECTION) == BOTAN_CIPHER_INIT_FLAG_ENCRYPT);
      const Botan::Cipher_Dir dir = encrypt_p ? Botan::ENCRYPTION : Botan::DECRYPTION;
      std::unique_ptr<Botan::Cipher_Mode> mode(Botan::get_cipher_mode(cipher_name, dir));
      if(!mode)
         return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
      *cipher = new botan_cipher_struct(mode.release());
      return BOTAN_FFI_SUCCESS;
      });
   }

int botan_cipher_destroy(botan_cipher_t cipher)
   {
   return BOTAN_FFI_CHECKED_DELETE(cipher);
   }

int botan_cipher_clear(botan_cipher_t cipher)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, { c.clear(); });
   }

int botan_cipher_query_keylen(botan_cipher_t cipher,
                              size_t* out_minimum_keylength,
                              size_t* out_maximum_keylength)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, {
      *out_minimum_keylength = c.key_spec().minimum_keylength();
      *out_maximum_keylength = c.key_spec().maximum_keylength();
      });
   }

int botan_cipher_set_key(botan_cipher_t cipher,
                         const uint8_t* key, size_t key_len)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, { c.set_key(key, key_len); });
   }

int botan_cipher_start(botan_cipher_t cipher_obj,
                       const uint8_t* nonce, size_t nonce_len)
   {
   return ffi_guard_thunk(BOTAN_CURRENT_FUNCTION, [=]() {
      Botan::Cipher_Mode& cipher = safe_get(cipher_obj);
      cipher.start(nonce, nonce_len);
      cipher_obj->m_buf.reserve(cipher.update_granularity());
      return BOTAN_FFI_SUCCESS;
      });
   }

int botan_cipher_update(botan_cipher_t cipher_obj,
                        uint32_t flags,
                        uint8_t output_ptr[],
                        size_t orig_output_size,
                        size_t* output_written,
                        const uint8_t input_ptr[],
                        size_t orig_input_size,
                        size_t* input_consumed)
   {
   return ffi_guard_thunk(BOTAN_CURRENT_FUNCTION, [=]() {

      size_t input_size = orig_input_size;
      size_t output_size = orig_output_size;
      const uint8_t* input = input_ptr;
      uint8_t* output = output_ptr;

      using namespace Botan;
      Cipher_Mode& cipher = safe_get(cipher_obj);
      secure_vector<uint8_t>& mbuf = cipher_obj->m_buf;

      const bool final_input = (flags & BOTAN_CIPHER_UPDATE_FLAG_FINAL);

      if(final_input)
         {
         mbuf.assign(input, input + input_size);
         *input_consumed = input_size;
         *output_written = 0;

         try
            {
            cipher.finish(mbuf);
            }
         catch(Integrity_Failure& e)
            {
            return BOTAN_FFI_ERROR_BAD_MAC;
            }

         *output_written = mbuf.size();

         if(mbuf.size() <= output_size)
            {
            copy_mem(output, mbuf.data(), mbuf.size());
            mbuf.clear();
            return BOTAN_FFI_SUCCESS;
            }

         return -1;
         }

      if(input_size == 0)
         {
         // Currently must take entire buffer in this case
         *output_written = mbuf.size();
         if(output_size >= mbuf.size())
            {
            copy_mem(output, mbuf.data(), mbuf.size());
            mbuf.clear();
            return BOTAN_FFI_SUCCESS;
            }

         return -1;
         }

      const size_t ud = cipher.update_granularity();
      BOTAN_ASSERT(cipher.update_granularity() > cipher.minimum_final_size(), "logic error");

      mbuf.resize(ud);
      size_t taken = 0, written = 0;

      while(input_size >= ud && output_size >= ud)
         {
         copy_mem(mbuf.data(), input, ud);
         cipher.update(mbuf);

         input_size -= ud;
         copy_mem(output, mbuf.data(), ud);
         input += ud;
         taken += ud;

         output_size -= ud;
         output += ud;
         written += ud;
         }

      *output_written = written;
      *input_consumed = taken;

      return BOTAN_FFI_SUCCESS;
      });
   }

int botan_cipher_set_associated_data(botan_cipher_t cipher,
                                     const uint8_t* ad,
                                     size_t ad_len)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, {
      if(Botan::AEAD_Mode* aead = dynamic_cast<Botan::AEAD_Mode*>(&c))
         {
         aead->set_associated_data(ad, ad_len);
         return BOTAN_FFI_SUCCESS;
         }
      return BOTAN_FFI_ERROR_BAD_PARAMETER;
      });
   }

int botan_cipher_valid_nonce_length(botan_cipher_t cipher, size_t nl)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, { return c.valid_nonce_length(nl) ? 1 : 0; });
   }

int botan_cipher_get_default_nonce_length(botan_cipher_t cipher, size_t* nl)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, { *nl = c.default_nonce_length(); });
   }

int botan_cipher_get_update_granularity(botan_cipher_t cipher, size_t* ug)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, { *ug = c.update_granularity(); });
   }

int botan_cipher_get_tag_length(botan_cipher_t cipher, size_t* tl)
   {
   return BOTAN_FFI_DO(Botan::Cipher_Mode, cipher, c, { *tl = c.tag_size(); });
   }

}