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1 : : /* crypto-ctx.c high-level crypto functions
2 : : * Copyright (C) 2002, 2003, 2007, 2010 Simon Josefsson
3 : : *
4 : : * This file is part of Shishi.
5 : : *
6 : : * Shishi is free software; you can redistribute it and/or modify it
7 : : * under the terms of the GNU General Public License as published by
8 : : * the Free Software Foundation; either version 3 of the License, or
9 : : * (at your option) any later version.
10 : : *
11 : : * Shishi is distributed in the hope that it will be useful, but
12 : : * WITHOUT ANY WARRANTY; without even the implied warranty of
13 : : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 : : * GNU General Public License for more details.
15 : : *
16 : : * You should have received a copy of the GNU General Public License
17 : : * along with Shishi; if not, see http://www.gnu.org/licenses or write
18 : : * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
19 : : * Floor, Boston, MA 02110-1301, USA
20 : : *
21 : : */
22 : :
23 : : #include "internal.h"
24 : :
25 : : struct Shishi_crypto
26 : : {
27 : : Shishi *handle;
28 : : Shishi_key *key;
29 : : int keyusage;
30 : : int32_t etype;
31 : : char *iv;
32 : : size_t ivlen;
33 : : };
34 : :
35 : : /**
36 : : * shishi_crypto:
37 : : * @handle: shishi handle as allocated by shishi_init().
38 : : * @key: key to encrypt with.
39 : : * @keyusage: integer specifying what this key will encrypt/decrypt.
40 : : * @etype: integer specifying what cipher to use.
41 : : * @iv: input array with initialization vector
42 : : * @ivlen: size of input array with initialization vector.
43 : : *
44 : : * Initialize a crypto context. This store a key, keyusage,
45 : : * encryption type and initialization vector in a "context", and the
46 : : * caller can then use this context to perform encryption via
47 : : * shishi_crypto_encrypt() and decryption via shishi_crypto_encrypt()
48 : : * without supplying all those details again. The functions also
49 : : * takes care of propagating the IV between calls.
50 : : *
51 : : * When the application no longer need to use the context, it should
52 : : * deallocate resources associated with it by calling
53 : : * shishi_crypto_close().
54 : : *
55 : : * Return value: Return a newly allocated crypto context.
56 : : **/
57 : : Shishi_crypto *
58 : 20 : shishi_crypto (Shishi * handle,
59 : : Shishi_key * key,
60 : : int keyusage, int32_t etype, const char *iv, size_t ivlen)
61 : : {
62 : : Shishi_crypto *ctx;
63 : : int rc;
64 : :
65 : 20 : ctx = xmalloc (sizeof (*ctx));
66 : :
67 : 20 : rc = shishi_key (handle, &ctx->key);
68 : : /* XXX handle rc, or rather:
69 : : change shishi_key() to return key instead of int. */
70 : 20 : shishi_key_copy (ctx->key, key);
71 : :
72 : 20 : ctx->handle = handle;
73 : 20 : ctx->keyusage = keyusage;
74 : 20 : ctx->etype = etype;
75 [ + + ]: 20 : if (iv)
76 : 16 : ctx->iv = xmemdup (iv, ivlen);
77 : : else
78 : 4 : ctx->iv = NULL;
79 : 20 : ctx->ivlen = ivlen;
80 : :
81 : 20 : return ctx;
82 : : }
83 : :
84 : : /**
85 : : * shishi_crypto_encrypt:
86 : : * @ctx: crypto context as returned by shishi_crypto().
87 : : * @in: input array with data to encrypt.
88 : : * @inlen: size of input array with data to encrypt.
89 : : * @out: output array with newly allocated encrypted data.
90 : : * @outlen: output variable with size of newly allocated output array.
91 : : *
92 : : * Encrypt data, using information (e.g., key and initialization
93 : : * vector) from context. The IV is updated inside the context after
94 : : * this call.
95 : : *
96 : : * When the application no longer need to use the context, it should
97 : : * deallocate resources associated with it by calling
98 : : * shishi_crypto_close().
99 : : *
100 : : * Return value: Returns %SHISHI_OK iff successful.
101 : : **/
102 : : int
103 : 336 : shishi_crypto_encrypt (Shishi_crypto * ctx,
104 : : const char *in, size_t inlen,
105 : : char **out, size_t * outlen)
106 : : {
107 : 336 : char *ivout = NULL;
108 : : size_t ivoutlen;
109 : : int rc;
110 : :
111 : 336 : rc = shishi_encrypt_ivupdate_etype (ctx->handle, ctx->key, ctx->keyusage,
112 : 336 : ctx->etype, ctx->iv, ctx->ivlen,
113 : : &ivout, &ivoutlen,
114 : : in, inlen, out, outlen);
115 [ + - ]: 336 : if (rc == SHISHI_OK)
116 : : {
117 : 336 : free (ctx->iv);
118 : 336 : ctx->iv = ivout;
119 : 336 : ctx->ivlen = ivoutlen;
120 : : }
121 : :
122 : 336 : return rc;
123 : : }
124 : :
125 : : /**
126 : : * shishi_crypto_decrypt:
127 : : * @ctx: crypto context as returned by shishi_crypto().
128 : : * @in: input array with data to decrypt.
129 : : * @inlen: size of input array with data to decrypt.
130 : : * @out: output array with newly allocated decrypted data.
131 : : * @outlen: output variable with size of newly allocated output array.
132 : : *
133 : : * Decrypt data, using information (e.g., key and initialization
134 : : * vector) from context. The IV is updated inside the context after
135 : : * this call.
136 : : *
137 : : * When the application no longer need to use the context, it should
138 : : * deallocate resources associated with it by calling
139 : : * shishi_crypto_close().
140 : : *
141 : : * Return value: Returns %SHISHI_OK iff successful.
142 : : **/
143 : : int
144 : 336 : shishi_crypto_decrypt (Shishi_crypto * ctx,
145 : : const char *in, size_t inlen,
146 : : char **out, size_t * outlen)
147 : : {
148 : 336 : char *ivout = NULL;
149 : : size_t ivoutlen;
150 : : int rc;
151 : :
152 : 336 : rc = shishi_decrypt_ivupdate_etype (ctx->handle, ctx->key, ctx->keyusage,
153 : 336 : ctx->etype, ctx->iv, ctx->ivlen,
154 : : &ivout, &ivoutlen,
155 : : in, inlen, out, outlen);
156 [ + - ]: 336 : if (rc == SHISHI_OK)
157 : : {
158 : 336 : free (ctx->iv);
159 : 336 : ctx->iv = ivout;
160 : 336 : ctx->ivlen = ivoutlen;
161 : : }
162 : :
163 : 336 : return rc;
164 : : }
165 : :
166 : : /**
167 : : * shishi_crypto_close:
168 : : * @ctx: crypto context as returned by shishi_crypto().
169 : : *
170 : : * Deallocate resources associated with the crypto context.
171 : : **/
172 : : void
173 : 20 : shishi_crypto_close (Shishi_crypto * ctx)
174 : : {
175 : 20 : shishi_key_done (ctx->key);
176 : 20 : free (ctx->iv);
177 : 20 : free (ctx);
178 : 20 : }
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