diff options
Diffstat (limited to 'src/lib/libcrypto/doc/EVP_EncryptInit.pod')
-rw-r--r-- | src/lib/libcrypto/doc/EVP_EncryptInit.pod | 359 |
1 files changed, 0 insertions, 359 deletions
diff --git a/src/lib/libcrypto/doc/EVP_EncryptInit.pod b/src/lib/libcrypto/doc/EVP_EncryptInit.pod deleted file mode 100644 index 9afe2396e2..0000000000 --- a/src/lib/libcrypto/doc/EVP_EncryptInit.pod +++ /dev/null | |||
@@ -1,359 +0,0 @@ | |||
1 | =pod | ||
2 | |||
3 | =head1 NAME | ||
4 | |||
5 | EVP_EncryptInit, EVP_EncryptUpdate, EVP_EncryptFinal, EVP_DecryptInit, | ||
6 | EVP_DecryptUpdate, EVP_DecryptFinal, EVP_CipherInit, EVP_CipherUpdate, | ||
7 | EVP_CipherFinal, EVP_CIPHER_CTX_set_key_length, EVP_CIPHER_CTX_ctrl, | ||
8 | EVP_CIPHER_CTX_cleanup, EVP_get_cipherbyname, EVP_get_cipherbynid, | ||
9 | EVP_get_cipherbyobj, EVP_CIPHER_nid, EVP_CIPHER_block_size, | ||
10 | EVP_CIPHER_key_length, EVP_CIPHER_iv_length, EVP_CIPHER_flags, | ||
11 | EVP_CIPHER_mode, EVP_CIPHER_type, EVP_CIPHER_CTX_cipher, EVP_CIPHER_CTX_nid, | ||
12 | EVP_CIPHER_CTX_block_size, EVP_CIPHER_CTX_key_length, EVP_CIPHER_CTX_iv_length, | ||
13 | EVP_CIPHER_CTX_get_app_data, EVP_CIPHER_CTX_set_app_data, EVP_CIPHER_CTX_type, | ||
14 | EVP_CIPHER_CTX_flags, EVP_CIPHER_CTX_mode, EVP_CIPHER_param_to_asn1, | ||
15 | EVP_CIPHER_asn1_to_param - EVP cipher routines | ||
16 | |||
17 | =head1 SYNOPSIS | ||
18 | |||
19 | #include <openssl/evp.h> | ||
20 | |||
21 | int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, | ||
22 | unsigned char *key, unsigned char *iv); | ||
23 | int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, | ||
24 | int *outl, unsigned char *in, int inl); | ||
25 | int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, | ||
26 | int *outl); | ||
27 | |||
28 | int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, | ||
29 | unsigned char *key, unsigned char *iv); | ||
30 | int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, | ||
31 | int *outl, unsigned char *in, int inl); | ||
32 | int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, | ||
33 | int *outl); | ||
34 | |||
35 | int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, | ||
36 | unsigned char *key, unsigned char *iv, int enc); | ||
37 | int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, | ||
38 | int *outl, unsigned char *in, int inl); | ||
39 | int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, | ||
40 | int *outl); | ||
41 | |||
42 | int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *x, int keylen); | ||
43 | int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr); | ||
44 | int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *a); | ||
45 | |||
46 | const EVP_CIPHER *EVP_get_cipherbyname(const char *name); | ||
47 | #define EVP_get_cipherbynid(a) EVP_get_cipherbyname(OBJ_nid2sn(a)) | ||
48 | #define EVP_get_cipherbyobj(a) EVP_get_cipherbynid(OBJ_obj2nid(a)) | ||
49 | |||
50 | #define EVP_CIPHER_nid(e) ((e)->nid) | ||
51 | #define EVP_CIPHER_block_size(e) ((e)->block_size) | ||
52 | #define EVP_CIPHER_key_length(e) ((e)->key_len) | ||
53 | #define EVP_CIPHER_iv_length(e) ((e)->iv_len) | ||
54 | #define EVP_CIPHER_flags(e) ((e)->flags) | ||
55 | #define EVP_CIPHER_mode(e) ((e)->flags) & EVP_CIPH_MODE) | ||
56 | int EVP_CIPHER_type(const EVP_CIPHER *ctx); | ||
57 | |||
58 | #define EVP_CIPHER_CTX_cipher(e) ((e)->cipher) | ||
59 | #define EVP_CIPHER_CTX_nid(e) ((e)->cipher->nid) | ||
60 | #define EVP_CIPHER_CTX_block_size(e) ((e)->cipher->block_size) | ||
61 | #define EVP_CIPHER_CTX_key_length(e) ((e)->key_len) | ||
62 | #define EVP_CIPHER_CTX_iv_length(e) ((e)->cipher->iv_len) | ||
63 | #define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data) | ||
64 | #define EVP_CIPHER_CTX_set_app_data(e,d) ((e)->app_data=(char *)(d)) | ||
65 | #define EVP_CIPHER_CTX_type(c) EVP_CIPHER_type(EVP_CIPHER_CTX_cipher(c)) | ||
66 | #define EVP_CIPHER_CTX_flags(e) ((e)->cipher->flags) | ||
67 | #define EVP_CIPHER_CTX_mode(e) ((e)->cipher->flags & EVP_CIPH_MODE) | ||
68 | |||
69 | int EVP_CIPHER_param_to_asn1(EVP_CIPHER_CTX *c, ASN1_TYPE *type); | ||
70 | int EVP_CIPHER_asn1_to_param(EVP_CIPHER_CTX *c, ASN1_TYPE *type); | ||
71 | |||
72 | =head1 DESCRIPTION | ||
73 | |||
74 | The EVP cipher routines are a high level interface to certain | ||
75 | symmetric ciphers. | ||
76 | |||
77 | EVP_EncryptInit() initializes a cipher context B<ctx> for encryption | ||
78 | with cipher B<type>. B<type> is normally supplied by a function such | ||
79 | as EVP_des_cbc() . B<key> is the symmetric key to use and B<iv> is the | ||
80 | IV to use (if necessary), the actual number of bytes used for the | ||
81 | key and IV depends on the cipher. It is possible to set all parameters | ||
82 | to NULL except B<type> in an initial call and supply the remaining | ||
83 | parameters in subsequent calls, all of which have B<type> set to NULL. | ||
84 | This is done when the default cipher parameters are not appropriate. | ||
85 | |||
86 | EVP_EncryptUpdate() encrypts B<inl> bytes from the buffer B<in> and | ||
87 | writes the encrypted version to B<out>. This function can be called | ||
88 | multiple times to encrypt successive blocks of data. The amount | ||
89 | of data written depends on the block alignment of the encrypted data: | ||
90 | as a result the amount of data written may be anything from zero bytes | ||
91 | to (inl + cipher_block_size - 1) so B<outl> should contain sufficient | ||
92 | room. The actual number of bytes written is placed in B<outl>. | ||
93 | |||
94 | EVP_EncryptFinal() encrypts the "final" data, that is any data that | ||
95 | remains in a partial block. It uses L<standard block padding|/NOTES> (aka PKCS | ||
96 | padding). The encrypted final data is written to B<out> which should | ||
97 | have sufficient space for one cipher block. The number of bytes written | ||
98 | is placed in B<outl>. After this function is called the encryption operation | ||
99 | is finished and no further calls to EVP_EncryptUpdate() should be made. | ||
100 | |||
101 | EVP_DecryptInit(), EVP_DecryptUpdate() and EVP_DecryptFinal() are the | ||
102 | corresponding decryption operations. EVP_DecryptFinal() will return an | ||
103 | error code if the final block is not correctly formatted. The parameters | ||
104 | and restrictions are identical to the encryption operations except that | ||
105 | the decrypted data buffer B<out> passed to EVP_DecryptUpdate() should | ||
106 | have sufficient room for (B<inl> + cipher_block_size) bytes unless the | ||
107 | cipher block size is 1 in which case B<inl> bytes is sufficient. | ||
108 | |||
109 | EVP_CipherInit(), EVP_CipherUpdate() and EVP_CipherFinal() are functions | ||
110 | that can be used for decryption or encryption. The operation performed | ||
111 | depends on the value of the B<enc> parameter. It should be set to 1 for | ||
112 | encryption, 0 for decryption and -1 to leave the value unchanged (the | ||
113 | actual value of 'enc' being supplied in a previous call). | ||
114 | |||
115 | EVP_CIPHER_CTX_cleanup() clears all information from a cipher context. | ||
116 | It should be called after all operations using a cipher are complete | ||
117 | so sensitive information does not remain in memory. | ||
118 | |||
119 | EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj() | ||
120 | return an EVP_CIPHER structure when passed a cipher name, a NID or an | ||
121 | ASN1_OBJECT structure. | ||
122 | |||
123 | EVP_CIPHER_nid() and EVP_CIPHER_CTX_nid() return the NID of a cipher when | ||
124 | passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX> structure. The actual NID | ||
125 | value is an internal value which may not have a corresponding OBJECT | ||
126 | IDENTIFIER. | ||
127 | |||
128 | EVP_CIPHER_key_length() and EVP_CIPHER_CTX_key_length() return the key | ||
129 | length of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX> | ||
130 | structure. The constant B<EVP_MAX_KEY_LENGTH> is the maximum key length | ||
131 | for all ciphers. Note: although EVP_CIPHER_key_length() is fixed for a | ||
132 | given cipher, the value of EVP_CIPHER_CTX_key_length() may be different | ||
133 | for variable key length ciphers. | ||
134 | |||
135 | EVP_CIPHER_CTX_set_key_length() sets the key length of the cipher ctx. | ||
136 | If the cipher is a fixed length cipher then attempting to set the key | ||
137 | length to any value other than the fixed value is an error. | ||
138 | |||
139 | EVP_CIPHER_iv_length() and EVP_CIPHER_CTX_iv_length() return the IV | ||
140 | length of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX>. | ||
141 | It will return zero if the cipher does not use an IV. The constant | ||
142 | B<EVP_MAX_IV_LENGTH> is the maximum IV length for all ciphers. | ||
143 | |||
144 | EVP_CIPHER_block_size() and EVP_CIPHER_CTX_block_size() return the block | ||
145 | size of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX> | ||
146 | structure. The constant B<EVP_MAX_IV_LENGTH> is also the maximum block | ||
147 | length for all ciphers. | ||
148 | |||
149 | EVP_CIPHER_type() and EVP_CIPHER_CTX_type() return the type of the passed | ||
150 | cipher or context. This "type" is the actual NID of the cipher OBJECT | ||
151 | IDENTIFIER as such it ignores the cipher parameters and 40 bit RC2 and | ||
152 | 128 bit RC2 have the same NID. If the cipher does not have an object | ||
153 | identifier or does not have ASN1 support this function will return | ||
154 | B<NID_undef>. | ||
155 | |||
156 | EVP_CIPHER_CTX_cipher() returns the B<EVP_CIPHER> structure when passed | ||
157 | an B<EVP_CIPHER_CTX> structure. | ||
158 | |||
159 | EVP_CIPHER_mode() and EVP_CIPHER_CTX_mode() return the block cipher mode: | ||
160 | EVP_CIPH_ECB_MODE, EVP_CIPH_CBC_MODE, EVP_CIPH_CFB_MODE or | ||
161 | EVP_CIPH_OFB_MODE. If the cipher is a stream cipher then | ||
162 | EVP_CIPH_STREAM_CIPHER is returned. | ||
163 | |||
164 | EVP_CIPHER_param_to_asn1() sets the AlgorithmIdentifier "parameter" based | ||
165 | on the passed cipher. This will typically include any parameters and an | ||
166 | IV. The cipher IV (if any) must be set when this call is made. This call | ||
167 | should be made before the cipher is actually "used" (before any | ||
168 | EVP_EncryptUpdate(), EVP_DecryptUpdate() calls for example). This function | ||
169 | may fail if the cipher does not have any ASN1 support. | ||
170 | |||
171 | EVP_CIPHER_asn1_to_param() sets the cipher parameters based on an ASN1 | ||
172 | AlgorithmIdentifier "parameter". The precise effect depends on the cipher | ||
173 | In the case of RC2, for example, it will set the IV and effective key length. | ||
174 | This function should be called after the base cipher type is set but before | ||
175 | the key is set. For example EVP_CipherInit() will be called with the IV and | ||
176 | key set to NULL, EVP_CIPHER_asn1_to_param() will be called and finally | ||
177 | EVP_CipherInit() again with all parameters except the key set to NULL. It is | ||
178 | possible for this function to fail if the cipher does not have any ASN1 support | ||
179 | or the parameters cannot be set (for example the RC2 effective key length | ||
180 | is not supported. | ||
181 | |||
182 | EVP_CIPHER_CTX_ctrl() allows various cipher specific parameters to be determined | ||
183 | and set. Currently only the RC2 effective key length and the number of rounds of | ||
184 | RC5 can be set. | ||
185 | |||
186 | =head1 RETURN VALUES | ||
187 | |||
188 | EVP_EncryptInit(), EVP_EncryptUpdate() and EVP_EncryptFinal() return 1 for success | ||
189 | and 0 for failure. | ||
190 | |||
191 | EVP_DecryptInit() and EVP_DecryptUpdate() return 1 for success and 0 for failure. | ||
192 | EVP_DecryptFinal() returns 0 if the decrypt failed or 1 for success. | ||
193 | |||
194 | EVP_CipherInit() and EVP_CipherUpdate() return 1 for success and 0 for failure. | ||
195 | EVP_CipherFinal() returns 1 for a decryption failure or 1 for success. | ||
196 | |||
197 | EVP_CIPHER_CTX_cleanup() returns 1 for success and 0 for failure. | ||
198 | |||
199 | EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj() | ||
200 | return an B<EVP_CIPHER> structure or NULL on error. | ||
201 | |||
202 | EVP_CIPHER_nid() and EVP_CIPHER_CTX_nid() return a NID. | ||
203 | |||
204 | EVP_CIPHER_block_size() and EVP_CIPHER_CTX_block_size() return the block | ||
205 | size. | ||
206 | |||
207 | EVP_CIPHER_key_length() and EVP_CIPHER_CTX_key_length() return the key | ||
208 | length. | ||
209 | |||
210 | EVP_CIPHER_iv_length() and EVP_CIPHER_CTX_iv_length() return the IV | ||
211 | length or zero if the cipher does not use an IV. | ||
212 | |||
213 | EVP_CIPHER_type() and EVP_CIPHER_CTX_type() return the NID of the cipher's | ||
214 | OBJECT IDENTIFIER or NID_undef if it has no defined OBJECT IDENTIFIER. | ||
215 | |||
216 | EVP_CIPHER_CTX_cipher() returns an B<EVP_CIPHER> structure. | ||
217 | |||
218 | EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param() return 1 for | ||
219 | success or zero for failure. | ||
220 | |||
221 | =head1 CIPHER LISTING | ||
222 | |||
223 | All algorithms have a fixed key length unless otherwise stated. | ||
224 | |||
225 | =over 4 | ||
226 | |||
227 | =item EVP_enc_null() | ||
228 | |||
229 | Null cipher: does nothing. | ||
230 | |||
231 | =item EVP_des_cbc(void), EVP_des_ecb(void), EVP_des_cfb(void), EVP_des_ofb(void) | ||
232 | |||
233 | DES in CBC, ECB, CFB and OFB modes respectively. | ||
234 | |||
235 | =item EVP_des_ede_cbc(void), EVP_des_ede(), EVP_des_ede_ofb(void), EVP_des_ede_cfb(void) | ||
236 | |||
237 | Two key triple DES in CBC, ECB, CFB and OFB modes respectively. | ||
238 | |||
239 | =item EVP_des_ede3_cbc(void), EVP_des_ede3(), EVP_des_ede3_ofb(void), EVP_des_ede3_cfb(void) | ||
240 | |||
241 | Three key triple DES in CBC, ECB, CFB and OFB modes respectively. | ||
242 | |||
243 | =item EVP_desx_cbc(void) | ||
244 | |||
245 | DESX algorithm in CBC mode. | ||
246 | |||
247 | =item EVP_rc4(void) | ||
248 | |||
249 | RC4 stream cipher. This is a variable key length cipher with default key length 128 bits. | ||
250 | |||
251 | =item EVP_rc4_40(void) | ||
252 | |||
253 | RC4 stream cipher with 40 bit key length. This is obsolete and new code should use EVP_rc4() | ||
254 | and the EVP_CIPHER_CTX_set_key_length() function. | ||
255 | |||
256 | =item EVP_idea_cbc() EVP_idea_ecb(void), EVP_idea_cfb(void), EVP_idea_ofb(void), EVP_idea_cbc(void) | ||
257 | |||
258 | IDEA encryption algorithm in CBC, ECB, CFB and OFB modes respectively. | ||
259 | |||
260 | =item EVP_rc2_cbc(void), EVP_rc2_ecb(void), EVP_rc2_cfb(void), EVP_rc2_ofb(void) | ||
261 | |||
262 | RC2 encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a variable key | ||
263 | length cipher with an additional parameter called "effective key bits" or "effective key length". | ||
264 | By default both are set to 128 bits. | ||
265 | |||
266 | =item EVP_rc2_40_cbc(void), EVP_rc2_64_cbc(void) | ||
267 | |||
268 | RC2 algorithm in CBC mode with a default key length and effective key length of 40 and 64 bits. | ||
269 | These are obsolete and new code should use EVP_rc2_cbc(), EVP_CIPHER_CTX_set_key_length() and | ||
270 | EVP_CIPHER_CTX_ctrl() to set the key length and effective key length. | ||
271 | |||
272 | =item EVP_bf_cbc(void), EVP_bf_ecb(void), EVP_bf_cfb(void), EVP_bf_ofb(void); | ||
273 | |||
274 | Blowfish encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a variable key | ||
275 | length cipher. | ||
276 | |||
277 | =item EVP_cast5_cbc(void), EVP_cast5_ecb(void), EVP_cast5_cfb(void), EVP_cast5_ofb(void) | ||
278 | |||
279 | CAST encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a variable key | ||
280 | length cipher. | ||
281 | |||
282 | =item EVP_rc5_32_12_16_cbc(void), EVP_rc5_32_12_16_ecb(void), EVP_rc5_32_12_16_cfb(void), EVP_rc5_32_12_16_ofb(void) | ||
283 | |||
284 | RC5 encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a variable key length | ||
285 | cipher with an additional "number of rounds" parameter. By default the key length is set to 128 | ||
286 | bits and 12 rounds. | ||
287 | |||
288 | =back | ||
289 | |||
290 | =head1 NOTES | ||
291 | |||
292 | Where possible the B<EVP> interface to symmetric ciphers should be used in | ||
293 | preference to the low level interfaces. This is because the code then becomes | ||
294 | transparent to the cipher used and much more flexible. | ||
295 | |||
296 | PKCS padding works by adding B<n> padding bytes of value B<n> to make the total | ||
297 | length of the encrypted data a multiple of the block size. Padding is always | ||
298 | added so if the data is already a multiple of the block size B<n> will equal | ||
299 | the block size. For example if the block size is 8 and 11 bytes are to be | ||
300 | encrypted then 5 padding bytes of value 5 will be added. | ||
301 | |||
302 | When decrypting the final block is checked to see if it has the correct form. | ||
303 | |||
304 | Although the decryption operation can produce an error, it is not a strong | ||
305 | test that the input data or key is correct. A random block has better than | ||
306 | 1 in 256 chance of being of the correct format and problems with the | ||
307 | input data earlier on will not produce a final decrypt error. | ||
308 | |||
309 | The functions EVP_EncryptInit(), EVP_EncryptUpdate(), EVP_EncryptFinal(), | ||
310 | EVP_DecryptInit(), EVP_DecryptUpdate(), EVP_CipherInit() and EVP_CipherUpdate() | ||
311 | and EVP_CIPHER_CTX_cleanup() did not return errors in OpenSSL version 0.9.5a or | ||
312 | earlier. Software only versions of encryption algorithms will never return | ||
313 | error codes for these functions, unless there is a programming error (for example | ||
314 | and attempt to set the key before the cipher is set in EVP_EncryptInit() ). | ||
315 | |||
316 | =head1 BUGS | ||
317 | |||
318 | For RC5 the number of rounds can currently only be set to 8, 12 or 16. This is | ||
319 | a limitation of the current RC5 code rather than the EVP interface. | ||
320 | |||
321 | It should be possible to disable PKCS padding: currently it isn't. | ||
322 | |||
323 | EVP_MAX_KEY_LENGTH and EVP_MAX_IV_LENGTH only refer to the internal ciphers with | ||
324 | default key lengths. If custom ciphers exceed these values the results are | ||
325 | unpredictable. This is because it has become standard practice to define a | ||
326 | generic key as a fixed unsigned char array containing EVP_MAX_KEY_LENGTH bytes. | ||
327 | |||
328 | The ASN1 code is incomplete (and sometimes inaccurate) it has only been tested | ||
329 | for certain common S/MIME ciphers (RC2, DES, triple DES) in CBC mode. | ||
330 | |||
331 | =head1 EXAMPLES | ||
332 | |||
333 | Get the number of rounds used in RC5: | ||
334 | |||
335 | int nrounds; | ||
336 | EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC5_ROUNDS, 0, &i); | ||
337 | |||
338 | Get the RC2 effective key length: | ||
339 | |||
340 | int key_bits; | ||
341 | EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC2_KEY_BITS, 0, &i); | ||
342 | |||
343 | Set the number of rounds used in RC5: | ||
344 | |||
345 | int nrounds; | ||
346 | EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, i, NULL); | ||
347 | |||
348 | Set the number of rounds used in RC2: | ||
349 | |||
350 | int nrounds; | ||
351 | EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC2_KEY_BITS, i, NULL); | ||
352 | |||
353 | =head1 SEE ALSO | ||
354 | |||
355 | L<evp(3)|evp(3)> | ||
356 | |||
357 | =head1 HISTORY | ||
358 | |||
359 | =cut | ||