summaryrefslogtreecommitdiff
path: root/ext/openssl/ossl_cipher.c
blob: e260a4b04f4c2542df419395ec1d3491ac0702b6 (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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
/*
 * $Id$
 * 'OpenSSL for Ruby' project
 * Copyright (C) 2001-2002  Michal Rokos <m.rokos@sh.cvut.cz>
 * All rights reserved.
 */
/*
 * This program is licenced under the same licence as Ruby.
 * (See the file 'LICENCE'.)
 */
#include "ossl.h"

#define MakeCipher(obj, klass, ctx) \
    obj = Data_Make_Struct(klass, EVP_CIPHER_CTX, 0, ossl_cipher_free, ctx)
#define GetCipher(obj, ctx) do { \
    Data_Get_Struct(obj, EVP_CIPHER_CTX, ctx); \
    if (!ctx) { \
	ossl_raise(rb_eRuntimeError, "Cipher not inititalized!"); \
    } \
} while (0)
#define SafeGetCipher(obj, ctx) do { \
    OSSL_Check_Kind(obj, cCipher); \
    GetCipher(obj, ctx); \
} while (0)

/*
 * Classes
 */
VALUE mCipher;
VALUE cCipher;
VALUE eCipherError;

static VALUE ossl_cipher_alloc(VALUE klass);

/*
 * PUBLIC
 */
const EVP_CIPHER *
GetCipherPtr(VALUE obj)
{
    EVP_CIPHER_CTX *ctx;

    SafeGetCipher(obj, ctx);

    return EVP_CIPHER_CTX_cipher(ctx);
}

VALUE
ossl_cipher_new(const EVP_CIPHER *cipher)
{
    VALUE ret;
    EVP_CIPHER_CTX *ctx;

    ret = ossl_cipher_alloc(cCipher);
    GetCipher(ret, ctx);
    EVP_CIPHER_CTX_init(ctx);
    if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, -1) != 1)
	ossl_raise(eCipherError, NULL);

    return ret;
}

/*
 * PRIVATE
 */
static void
ossl_cipher_free(EVP_CIPHER_CTX *ctx)
{
    if (ctx) {
	EVP_CIPHER_CTX_cleanup(ctx);
	free(ctx);
    }
}

static VALUE
ossl_cipher_alloc(VALUE klass)
{
    EVP_CIPHER_CTX *ctx;
    VALUE obj;

    MakeCipher(obj, klass, ctx);
    EVP_CIPHER_CTX_init(ctx);
	
    return obj;
}

/*
 *  call-seq:
 *     Cipher.new(string) -> cipher
 *
 *  The string must contain a valid cipher name like "AES-128-CBC" or "3DES".
 *
 *  A list of cipher names is available by calling OpenSSL::Cipher.ciphers.
 */
static VALUE
ossl_cipher_initialize(VALUE self, VALUE str)
{
    EVP_CIPHER_CTX *ctx;
    const EVP_CIPHER *cipher;
    char *name;

    name = StringValuePtr(str);
    GetCipher(self, ctx);
    if (!(cipher = EVP_get_cipherbyname(name))) {
	ossl_raise(rb_eRuntimeError, "unsupported cipher algorithm (%s)", name);
    }
    if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, -1) != 1)
	ossl_raise(eCipherError, NULL);

    return self;
}
static VALUE
ossl_cipher_copy(VALUE self, VALUE other)
{
    EVP_CIPHER_CTX *ctx1, *ctx2;
	
    rb_check_frozen(self);
    if (self == other) return self;

    GetCipher(self, ctx1);
    SafeGetCipher(other, ctx2);
    if (EVP_CIPHER_CTX_copy(ctx1, ctx2) != 1)
	ossl_raise(eCipherError, NULL);

    return self;
}

static void*
add_cipher_name_to_ary(const OBJ_NAME *name, VALUE ary)
{
    rb_ary_push(ary, rb_str_new2(name->name));
    return NULL;
}

/*
 *  call-seq:
 *     Cipher.ciphers -> array[string...]
 *
 *  Returns the names of all available ciphers in an array.
 */
static VALUE
ossl_s_ciphers(VALUE self)
{
#ifdef HAVE_OBJ_NAME_DO_ALL_SORTED
    VALUE ary;

    ary = rb_ary_new();
    OBJ_NAME_do_all_sorted(OBJ_NAME_TYPE_CIPHER_METH,
                    (void(*)(const OBJ_NAME*,void*))add_cipher_name_to_ary,
                    (void*)ary);

    return ary;
#else
    rb_notimplement();
#endif
}

/*
 *  call-seq:
 *     cipher.reset -> self
 *
 *  Internally calls EVP_CipherInit_ex(ctx, NULL, NULL, NULL, NULL, -1).
 */
static VALUE
ossl_cipher_reset(VALUE self)
{
    EVP_CIPHER_CTX *ctx;

    GetCipher(self, ctx);
    if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, NULL, -1) != 1)
	ossl_raise(eCipherError, NULL);
		
    return self;
}

static VALUE
ossl_cipher_init(int argc, VALUE *argv, VALUE self, int mode)
{
    EVP_CIPHER_CTX *ctx;
    unsigned char key[EVP_MAX_KEY_LENGTH], *p_key = NULL;
    unsigned char iv[EVP_MAX_IV_LENGTH], *p_iv = NULL;
    VALUE pass, init_v;

    if(rb_scan_args(argc, argv, "02", &pass, &init_v) > 0){
	/*
	 * oops. this code mistakes salt for IV.
	 * We deprecated the arguments for this method, but we decided
	 * keeping this behaviour for backward compatibility.
	 */
	char *cname  = rb_class2name(rb_obj_class(self));
	rb_warn("argumtents for %s#encrypt and %s#decrypt were deprecated; "
                "use %s#pkcs5_keyivgen to derive key and IV",
                cname, cname, cname);
	StringValue(pass);
	GetCipher(self, ctx);
	if (NIL_P(init_v)) memcpy(iv, "OpenSSL for Ruby rulez!", sizeof(iv));
	else{
	    StringValue(init_v);
	    if (EVP_MAX_IV_LENGTH > RSTRING_LEN(init_v)) {
		memset(iv, 0, EVP_MAX_IV_LENGTH);
		memcpy(iv, RSTRING_PTR(init_v), RSTRING_LEN(init_v));
	    }
	    else memcpy(iv, RSTRING_PTR(init_v), sizeof(iv));
	}
	EVP_BytesToKey(EVP_CIPHER_CTX_cipher(ctx), EVP_md5(), iv,
		       RSTRING_PTR(pass), RSTRING_LEN(pass), 1, key, NULL);
	p_key = key;
	p_iv = iv;
    }
    else {
	GetCipher(self, ctx);
    }
    if (EVP_CipherInit_ex(ctx, NULL, NULL, p_key, p_iv, mode) != 1) {
	ossl_raise(eCipherError, NULL);
    }

    return self;
}

/*
 *  call-seq:
 *     cipher.encrypt -> self
 *
 *  Make sure to call .encrypt or .decrypt before using any of the following methods:
 *  * [key=, iv=, random_key, random_iv, pkcs5_keyivgen]
 *
 *  Internally calls EVP_CipherInit_ex(ctx, NULL, NULL, NULL, NULL, 1).
 */
static VALUE
ossl_cipher_encrypt(int argc, VALUE *argv, VALUE self)
{
    return ossl_cipher_init(argc, argv, self, 1);
}

/*
 *  call-seq:
 *     cipher.decrypt -> self
 *
 *  Make sure to call .encrypt or .decrypt before using any of the following methods:
 *  * [key=, iv=, random_key, random_iv, pkcs5_keyivgen]
 *
 *  Internally calls EVP_CipherInit_ex(ctx, NULL, NULL, NULL, NULL, 0).
 */
static VALUE
ossl_cipher_decrypt(int argc, VALUE *argv, VALUE self)
{
    return ossl_cipher_init(argc, argv, self, 0);
}

/*
 *  call-seq:
 *     cipher.pkcs5_keyivgen(pass [, salt [, iterations [, digest]]] ) -> nil
 *
 *  Generates and sets the key/iv based on a password.
 *
 *  WARNING: This method is only PKCS5 v1.5 compliant when using RC2, RC4-40, or DES
 *  with MD5 or SHA1.  Using anything else (like AES) will generate the key/iv using an
 *  OpenSSL specific method.  Use a PKCS5 v2 key generation method instead.
 *
 *  === Parameters
 *  +salt+ must be an 8 byte string if provided.
 *  +iterations+ is a integer with a default of 2048.
 *  +digest+ is a Digest object that defaults to 'MD5'
 *
 *  A minimum of 1000 iterations is recommended.
 *
 */
static VALUE
ossl_cipher_pkcs5_keyivgen(int argc, VALUE *argv, VALUE self)
{
    EVP_CIPHER_CTX *ctx;
    const EVP_MD *digest;
    VALUE vpass, vsalt, viter, vdigest;
    unsigned char key[EVP_MAX_KEY_LENGTH], iv[EVP_MAX_IV_LENGTH], *salt = NULL;
    int iter;

    rb_scan_args(argc, argv, "13", &vpass, &vsalt, &viter, &vdigest);
    StringValue(vpass);
    if(!NIL_P(vsalt)){
	StringValue(vsalt);
	if(RSTRING_LEN(vsalt) != PKCS5_SALT_LEN)
	    rb_raise(eCipherError, "salt must be an 8-octet string");
	salt = RSTRING_PTR(vsalt);
    }
    iter = NIL_P(viter) ? 2048 : NUM2INT(viter);
    digest = NIL_P(vdigest) ? EVP_md5() : GetDigestPtr(vdigest);
    GetCipher(self, ctx);
    EVP_BytesToKey(EVP_CIPHER_CTX_cipher(ctx), digest, salt,
		   RSTRING_PTR(vpass), RSTRING_LEN(vpass), iter, key, iv); 
    if (EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, -1) != 1)
	ossl_raise(eCipherError, NULL);
    OPENSSL_cleanse(key, sizeof key);
    OPENSSL_cleanse(iv, sizeof iv);

    return Qnil;
}

/*
 *  call-seq:
 *     cipher.update(string) -> aString
 *
 */
static VALUE 
ossl_cipher_update(VALUE self, VALUE data)
{
    EVP_CIPHER_CTX *ctx;
    char *in;
    int in_len, out_len;
    VALUE str;

    StringValue(data);
    in = RSTRING_PTR(data);
    if ((in_len = RSTRING_LEN(data)) == 0)
        rb_raise(rb_eArgError, "data must not be empty");
    GetCipher(self, ctx);
    str = rb_str_new(0, in_len+EVP_CIPHER_CTX_block_size(ctx));
    if (!EVP_CipherUpdate(ctx, RSTRING_PTR(str), &out_len, in, in_len))
	ossl_raise(eCipherError, NULL);
    assert(out_len < RSTRING_LEN(str));
    rb_str_set_len(str, out_len);

    return str;
}

/*
 *  call-seq:
 *     cipher.final -> aString
 *
 *  Returns the remaining data held in the cipher object.  Further calls to update() or final() will return garbage.
 *
 *  See EVP_CipherFinal_ex for further information.
 */
static VALUE 
ossl_cipher_final(VALUE self)
{
    EVP_CIPHER_CTX *ctx;
    int out_len;
    VALUE str;

    GetCipher(self, ctx);
    str = rb_str_new(0, EVP_CIPHER_CTX_block_size(ctx));
    if (!EVP_CipherFinal_ex(ctx, RSTRING_PTR(str), &out_len))
	ossl_raise(eCipherError, NULL);
    assert(out_len <= RSTRING_LEN(str));
    rb_str_set_len(str, out_len);

    return str;
}

/*
 *  call-seq:
 *     cipher.name -> string
 *
 *  Returns the name of the cipher which may differ slightly from the original name provided.
 */
static VALUE
ossl_cipher_name(VALUE self)
{
    EVP_CIPHER_CTX *ctx;

    GetCipher(self, ctx);

    return rb_str_new2(EVP_CIPHER_name(EVP_CIPHER_CTX_cipher(ctx)));
}

/*
 *  call-seq:
 *     cipher.key = string -> string
 *
 *  Sets the cipher key.
 *
 *  Only call this method after calling cipher.encrypt or cipher.decrypt.
 */
static VALUE
ossl_cipher_set_key(VALUE self, VALUE key)
{
    EVP_CIPHER_CTX *ctx;

    StringValue(key);
    GetCipher(self, ctx);

    if (RSTRING_LEN(key) < EVP_CIPHER_CTX_key_length(ctx))
        ossl_raise(eCipherError, "key length too short");

    if (EVP_CipherInit_ex(ctx, NULL, NULL, RSTRING_PTR(key), NULL, -1) != 1)
        ossl_raise(eCipherError, NULL);

    return key;
}

/*
 *  call-seq:
 *     cipher.iv = string -> string
 *
 *  Sets the cipher iv.
 *
 *  Only call this method after calling cipher.encrypt or cipher.decrypt.
 */
static VALUE
ossl_cipher_set_iv(VALUE self, VALUE iv)
{
    EVP_CIPHER_CTX *ctx;

    StringValue(iv);
    GetCipher(self, ctx);

    if (RSTRING_LEN(iv) < EVP_CIPHER_CTX_iv_length(ctx))
        ossl_raise(eCipherError, "iv length too short");

    if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, RSTRING_PTR(iv), -1) != 1)
	ossl_raise(eCipherError, NULL);

    return iv;
}


/*
 *  call-seq:
 *     cipher.key_length = integer -> integer
 *
 *  Sets the key length of the cipher.  If the cipher is a fixed length cipher then attempting to set the key
 *  length to any value other than the fixed value is an error.
 *
 *  Under normal circumstances you do not need to call this method (and probably shouldn't).
 *
 *  See EVP_CIPHER_CTX_set_key_length for further information.
 */
static VALUE
ossl_cipher_set_key_length(VALUE self, VALUE key_length)
{
    int len = NUM2INT(key_length);
    EVP_CIPHER_CTX *ctx;
 
    GetCipher(self, ctx);
    if (EVP_CIPHER_CTX_set_key_length(ctx, len) != 1)
        ossl_raise(eCipherError, NULL);

    return key_length;
}

/*
 *  call-seq:
 *     cipher.padding = integer -> integer
 *
 *  Enables or disables padding. By default encryption operations are padded using standard block padding and the
 *  padding is checked and removed when decrypting. If the pad parameter is zero then no padding is performed, the
 *  total amount of data encrypted or decrypted must then be a multiple of the block size or an error will occur.
 *
 *  See EVP_CIPHER_CTX_set_padding for further information.
 */
static VALUE
ossl_cipher_set_padding(VALUE self, VALUE padding)
{
#if defined(HAVE_EVP_CIPHER_CTX_SET_PADDING)
    EVP_CIPHER_CTX *ctx;
    int pad = NUM2INT(padding);

    GetCipher(self, ctx);
    if (EVP_CIPHER_CTX_set_padding(ctx, pad) != 1)
	ossl_raise(eCipherError, NULL);
#else
    rb_notimplement();
#endif
    return padding;
}

#define CIPHER_0ARG_INT(func)					\
    static VALUE						\
    ossl_cipher_##func(VALUE self)				\
    {								\
	EVP_CIPHER_CTX *ctx;					\
	GetCipher(self, ctx);					\
	return INT2NUM(EVP_CIPHER_##func(EVP_CIPHER_CTX_cipher(ctx)));	\
    }
CIPHER_0ARG_INT(key_length)
CIPHER_0ARG_INT(iv_length)
CIPHER_0ARG_INT(block_size)

#if 0
/*
 *  call-seq:
 *     cipher.key_length -> integer
 *
 */
static VALUE ossl_cipher_key_length() { }
/*
 *  call-seq:
 *     cipher.iv_length -> integer
 *
 */
static VALUE ossl_cipher_iv_length() { }
/*
 *  call-seq:
 *     cipher.block_size -> integer
 *
 */
static VALUE ossl_cipher_block_size() { }
#endif

/*
 * INIT
 */
void 
Init_ossl_cipher(void)
{
#if 0 /* let rdoc know about mOSSL */
    mOSSL = rb_define_module("OpenSSL");
#endif
    mCipher = rb_define_module_under(mOSSL, "Cipher");
    eCipherError = rb_define_class_under(mOSSL, "CipherError", eOSSLError);
    cCipher = rb_define_class_under(mCipher, "Cipher", rb_cObject);

    rb_define_alloc_func(cCipher, ossl_cipher_alloc);
    rb_define_copy_func(cCipher, ossl_cipher_copy);
    rb_define_module_function(mCipher, "ciphers", ossl_s_ciphers, 0);
    rb_define_method(cCipher, "initialize", ossl_cipher_initialize, 1);
    rb_define_method(cCipher, "reset", ossl_cipher_reset, 0);
    rb_define_method(cCipher, "encrypt", ossl_cipher_encrypt, -1);
    rb_define_method(cCipher, "decrypt", ossl_cipher_decrypt, -1);
    rb_define_method(cCipher, "pkcs5_keyivgen", ossl_cipher_pkcs5_keyivgen, -1);
    rb_define_method(cCipher, "update", ossl_cipher_update, 1);
    rb_define_method(cCipher, "final", ossl_cipher_final, 0);
    rb_define_method(cCipher, "name", ossl_cipher_name, 0);
    rb_define_method(cCipher, "key=", ossl_cipher_set_key, 1);
    rb_define_method(cCipher, "key_len=", ossl_cipher_set_key_length, 1);
    rb_define_method(cCipher, "key_len", ossl_cipher_key_length, 0);
    rb_define_method(cCipher, "iv=", ossl_cipher_set_iv, 1);
    rb_define_method(cCipher, "iv_len", ossl_cipher_iv_length, 0);
    rb_define_method(cCipher, "block_size", ossl_cipher_block_size, 0);
    rb_define_method(cCipher, "padding=", ossl_cipher_set_padding, 1);

    rb_define_const(mCipher, "PKCS5_SALT_LEN", PKCS5_SALT_LEN);
}