1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_EVP_H
58 #define OPENSSL_HEADER_EVP_H
59 
60 #include <openssl/base.h>
61 
62 #include <openssl/thread.h>
63 
64 /* OpenSSL included digest and cipher functions in this header so we include
65  * them for users that still expect that.
66  *
67  * TODO(fork): clean up callers so that they include what they use. */
68 #include <openssl/aead.h>
69 #include <openssl/base64.h>
70 #include <openssl/cipher.h>
71 #include <openssl/digest.h>
72 #include <openssl/obj.h>
73 
74 #if defined(__cplusplus)
75 extern "C" {
76 #endif
77 
78 
79 /* EVP abstracts over public/private key algorithms. */
80 
81 
82 /* Public key objects. */
83 
84 /* EVP_PKEY_new creates a new, empty public-key object and returns it or NULL
85  * on allocation failure. */
86 OPENSSL_EXPORT EVP_PKEY *EVP_PKEY_new(void);
87 
88 /* EVP_PKEY_free frees all data referenced by |pkey| and then frees |pkey|
89  * itself. */
90 OPENSSL_EXPORT void EVP_PKEY_free(EVP_PKEY *pkey);
91 
92 /* EVP_PKEY_up_ref increments the reference count of |pkey| and returns it. */
93 OPENSSL_EXPORT EVP_PKEY *EVP_PKEY_up_ref(EVP_PKEY *pkey);
94 
95 /* EVP_PKEY_is_opaque returns one if |pkey| is opaque. Opaque keys are backed by
96  * custom implementations which do not expose key material and parameters. It is
97  * an error to attempt to duplicate, export, or compare an opaque key. */
98 OPENSSL_EXPORT int EVP_PKEY_is_opaque(const EVP_PKEY *pkey);
99 
100 /* EVP_PKEY_supports_digest returns one if |pkey| supports digests of
101  * type |md|. This is intended for use with EVP_PKEYs backing custom
102  * implementations which can't sign all digests. */
103 OPENSSL_EXPORT int EVP_PKEY_supports_digest(const EVP_PKEY *pkey,
104                                             const EVP_MD *md);
105 
106 /* EVP_PKEY_cmp compares |a| and |b| and returns one if they are equal, zero if
107  * not and a negative number on error.
108  *
109  * WARNING: this differs from the traditional return value of a "cmp"
110  * function. */
111 OPENSSL_EXPORT int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b);
112 
113 /* EVP_PKEY_copy_parameters sets the parameters of |to| to equal the parameters
114  * of |from|. It returns one on success and zero on error. */
115 OPENSSL_EXPORT int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from);
116 
117 /* EVP_PKEY_missing_parameters returns one if |pkey| is missing needed
118  * parameters or zero if not, or if the algorithm doesn't take parameters. */
119 OPENSSL_EXPORT int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey);
120 
121 /* EVP_PKEY_size returns the maximum size, in bytes, of a signature signed by
122  * |pkey|. For an RSA key, this returns the number of bytes needed to represent
123  * the modulus. For an EC key, this returns the maximum size of a DER-encoded
124  * ECDSA signature. */
125 OPENSSL_EXPORT int EVP_PKEY_size(const EVP_PKEY *pkey);
126 
127 /* EVP_PKEY_bits returns the "size", in bits, of |pkey|. For an RSA key, this
128  * returns the bit length of the modulus. For an EC key, this returns the bit
129  * length of the group order. */
130 OPENSSL_EXPORT int EVP_PKEY_bits(EVP_PKEY *pkey);
131 
132 /* EVP_PKEY_id returns the type of |pkey|, which is one of the |EVP_PKEY_*|
133  * values. */
134 OPENSSL_EXPORT int EVP_PKEY_id(const EVP_PKEY *pkey);
135 
136 /* EVP_PKEY_type returns a canonicalised form of |NID|. For example,
137  * |EVP_PKEY_RSA2| will be turned into |EVP_PKEY_RSA|. */
138 OPENSSL_EXPORT int EVP_PKEY_type(int nid);
139 
140 
141 /* Getting and setting concrete public key types.
142  *
143  * The following functions get and set the underlying public key in an
144  * |EVP_PKEY| object. The |set1| functions take an additional reference to the
145  * underlying key and return one on success or zero on error. The |assign|
146  * functions adopt the caller's reference. The |get1| functions return a fresh
147  * reference to the underlying object or NULL if |pkey| is not of the correct
148  * type. The |get0| functions behave the same but return a non-owning
149  * pointer. */
150 
151 OPENSSL_EXPORT int EVP_PKEY_set1_RSA(EVP_PKEY *pkey, RSA *key);
152 OPENSSL_EXPORT int EVP_PKEY_assign_RSA(EVP_PKEY *pkey, RSA *key);
153 OPENSSL_EXPORT RSA *EVP_PKEY_get0_RSA(EVP_PKEY *pkey);
154 OPENSSL_EXPORT RSA *EVP_PKEY_get1_RSA(EVP_PKEY *pkey);
155 
156 OPENSSL_EXPORT int EVP_PKEY_set1_DSA(EVP_PKEY *pkey, DSA *key);
157 OPENSSL_EXPORT int EVP_PKEY_assign_DSA(EVP_PKEY *pkey, DSA *key);
158 OPENSSL_EXPORT DSA *EVP_PKEY_get0_DSA(EVP_PKEY *pkey);
159 OPENSSL_EXPORT DSA *EVP_PKEY_get1_DSA(EVP_PKEY *pkey);
160 
161 OPENSSL_EXPORT int EVP_PKEY_set1_EC_KEY(EVP_PKEY *pkey, EC_KEY *key);
162 OPENSSL_EXPORT int EVP_PKEY_assign_EC_KEY(EVP_PKEY *pkey, EC_KEY *key);
163 OPENSSL_EXPORT EC_KEY *EVP_PKEY_get0_EC_KEY(EVP_PKEY *pkey);
164 OPENSSL_EXPORT EC_KEY *EVP_PKEY_get1_EC_KEY(EVP_PKEY *pkey);
165 
166 #define EVP_PKEY_NONE NID_undef
167 #define EVP_PKEY_RSA NID_rsaEncryption
168 #define EVP_PKEY_RSA2 NID_rsa
169 #define EVP_PKEY_DSA NID_dsa
170 #define EVP_PKEY_EC NID_X9_62_id_ecPublicKey
171 
172 /* EVP_PKEY_assign sets the underlying key of |pkey| to |key|, which must be of
173  * the given type. The |type| argument should be one of the |EVP_PKEY_*|
174  * values. */
175 OPENSSL_EXPORT int EVP_PKEY_assign(EVP_PKEY *pkey, int type, void *key);
176 
177 /* EVP_PKEY_set_type sets the type of |pkey| to |type|, which should be one of
178  * the |EVP_PKEY_*| values. It returns one if sucessful or zero otherwise. If
179  * |pkey| is NULL, it simply reports whether the type is known. */
180 OPENSSL_EXPORT int EVP_PKEY_set_type(EVP_PKEY *pkey, int type);
181 
182 /* EVP_PKEY_cmp_parameters compares the parameters of |a| and |b|. It returns
183  * one if they match, zero if not, or a negative number of on error.
184  *
185  * WARNING: the return value differs from the usual return value convention. */
186 OPENSSL_EXPORT int EVP_PKEY_cmp_parameters(const EVP_PKEY *a,
187                                            const EVP_PKEY *b);
188 
189 
190 /* ASN.1 functions */
191 
192 /* d2i_PrivateKey parses an ASN.1, DER-encoded, private key from |len| bytes at
193  * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in
194  * |*out|. If |*out| is already non-NULL on entry then the result is written
195  * directly into |*out|, otherwise a fresh |EVP_PKEY| is allocated. On
196  * successful exit, |*inp| is advanced past the DER structure. It returns the
197  * result or NULL on error. */
198 OPENSSL_EXPORT EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **out,
199                                         const uint8_t **inp, long len);
200 
201 /* d2i_AutoPrivateKey acts the same as |d2i_PrivateKey|, but detects the type
202  * of the private key. */
203 OPENSSL_EXPORT EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **out, const uint8_t **inp,
204                                             long len);
205 
206 /* i2d_PrivateKey marshals a private key from |key| to an ASN.1, DER
207  * structure. If |outp| is not NULL then the result is written to |*outp| and
208  * |*outp| is advanced just past the output. It returns the number of bytes in
209  * the result, whether written or not, or a negative value on error. */
210 OPENSSL_EXPORT int i2d_PrivateKey(const EVP_PKEY *key, uint8_t **outp);
211 
212 /* i2d_PublicKey marshals a public key from |key| to a type-specific format.
213  * If |outp| is not NULL then the result is written to |*outp| and
214  * |*outp| is advanced just past the output. It returns the number of bytes in
215  * the result, whether written or not, or a negative value on error.
216  *
217  * RSA keys are serialized as a DER-encoded RSAPublicKey (RFC 3447) structure.
218  * EC keys are serialized as an EC point per SEC 1. */
219 OPENSSL_EXPORT int i2d_PublicKey(EVP_PKEY *key, uint8_t **outp);
220 
221 
222 /* Signing */
223 
224 /* EVP_DigestSignInit sets up |ctx| for a signing operation with |type| and
225  * |pkey|. The |ctx| argument must have been initialised with
226  * |EVP_MD_CTX_init|. If |pctx| is not NULL, the |EVP_PKEY_CTX| of the signing
227  * operation will be written to |*pctx|; this can be used to set alternative
228  * signing options.
229  *
230  * It returns one on success, or zero on error. */
231 OPENSSL_EXPORT int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
232                                       const EVP_MD *type, ENGINE *e,
233                                       EVP_PKEY *pkey);
234 
235 /* EVP_DigestSignUpdate appends |len| bytes from |data| to the data which will
236  * be signed in |EVP_DigestSignFinal|. It returns one. */
237 OPENSSL_EXPORT int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *data,
238                                         size_t len);
239 
240 /* EVP_DigestSignFinal signs the data that has been included by one or more
241  * calls to |EVP_DigestSignUpdate|. If |out_sig| is NULL then |*out_sig_len| is
242  * set to the maximum number of output bytes. Otherwise, on entry,
243  * |*out_sig_len| must contain the length of the |out_sig| buffer. If the call
244  * is successful, the signature is written to |out_sig| and |*out_sig_len| is
245  * set to its length.
246  *
247  * It returns one on success, or zero on error. */
248 OPENSSL_EXPORT int EVP_DigestSignFinal(EVP_MD_CTX *ctx, uint8_t *out_sig,
249                                        size_t *out_sig_len);
250 
251 /* EVP_DigestSignAlgorithm encodes the signing parameters of |ctx| as an
252  * AlgorithmIdentifer and saves the result in |algor|.
253  *
254  * It returns one on success, or zero on error.
255  *
256  * TODO(davidben): This API should eventually lose the dependency on
257  * crypto/asn1/. */
258 OPENSSL_EXPORT int EVP_DigestSignAlgorithm(EVP_MD_CTX *ctx, X509_ALGOR *algor);
259 
260 
261 /* Verifying */
262 
263 /* EVP_DigestVerifyInit sets up |ctx| for a signature verification operation
264  * with |type| and |pkey|. The |ctx| argument must have been initialised with
265  * |EVP_MD_CTX_init|. If |pctx| is not NULL, the |EVP_PKEY_CTX| of the signing
266  * operation will be written to |*pctx|; this can be used to set alternative
267  * signing options.
268  *
269  * It returns one on success, or zero on error. */
270 OPENSSL_EXPORT int EVP_DigestVerifyInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
271                                         const EVP_MD *type, ENGINE *e,
272                                         EVP_PKEY *pkey);
273 
274 /* EVP_DigestVerifyInitFromAlgorithm sets up |ctx| for a signature verification
275  * operation with public key |pkey| and parameters from |algor|. The |ctx|
276  * argument must have been initialised with |EVP_MD_CTX_init|.
277  *
278  * It returns one on success, or zero on error.
279  *
280  * TODO(davidben): This API should eventually lose the dependency on
281  * crypto/asn1/. */
282 OPENSSL_EXPORT int EVP_DigestVerifyInitFromAlgorithm(EVP_MD_CTX *ctx,
283                                                      X509_ALGOR *algor,
284                                                      EVP_PKEY *pkey);
285 
286 /* EVP_DigestVerifyUpdate appends |len| bytes from |data| to the data which
287  * will be verified by |EVP_DigestVerifyFinal|. It returns one. */
288 OPENSSL_EXPORT int EVP_DigestVerifyUpdate(EVP_MD_CTX *ctx, const void *data,
289                                           size_t len);
290 
291 /* EVP_DigestVerifyFinal verifies that |sig_len| bytes of |sig| are a valid
292  * signature for the data that has been included by one or more calls to
293  * |EVP_DigestVerifyUpdate|. It returns one on success and zero otherwise. */
294 OPENSSL_EXPORT int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const uint8_t *sig,
295                                          size_t sig_len);
296 
297 
298 /* Signing (old functions) */
299 
300 /* EVP_SignInit_ex configures |ctx|, which must already have been initialised,
301  * for a fresh signing operation using the hash function |type|. It returns one
302  * on success and zero otherwise.
303  *
304  * (In order to initialise |ctx|, either obtain it initialised with
305  * |EVP_MD_CTX_create|, or use |EVP_MD_CTX_init|.) */
306 OPENSSL_EXPORT int EVP_SignInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type,
307                                    ENGINE *impl);
308 
309 /* EVP_SignInit is a deprecated version of |EVP_SignInit_ex|.
310  *
311  * TODO(fork): remove. */
312 OPENSSL_EXPORT int EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type);
313 
314 /* EVP_SignUpdate appends |len| bytes from |data| to the data which will be
315  * signed in |EVP_SignFinal|. */
316 OPENSSL_EXPORT int EVP_SignUpdate(EVP_MD_CTX *ctx, const void *data,
317                                   size_t len);
318 
319 /* EVP_SignFinal signs the data that has been included by one or more calls to
320  * |EVP_SignUpdate|, using the key |pkey|, and writes it to |sig|. On entry,
321  * |sig| must point to at least |EVP_PKEY_size(pkey)| bytes of space. The
322  * actual size of the signature is written to |*out_sig_len|.
323  *
324  * It returns one on success and zero otherwise.
325  *
326  * It does not modify |ctx|, thus it's possible to continue to use |ctx| in
327  * order to sign a longer message. */
328 OPENSSL_EXPORT int EVP_SignFinal(const EVP_MD_CTX *ctx, uint8_t *sig,
329                                  unsigned int *out_sig_len, EVP_PKEY *pkey);
330 
331 
332 /* Verifying (old functions) */
333 
334 /* EVP_VerifyInit_ex configures |ctx|, which must already have been
335  * initialised, for a fresh signature verification operation using the hash
336  * function |type|. It returns one on success and zero otherwise.
337  *
338  * (In order to initialise |ctx|, either obtain it initialised with
339  * |EVP_MD_CTX_create|, or use |EVP_MD_CTX_init|.) */
340 OPENSSL_EXPORT int EVP_VerifyInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type,
341                                      ENGINE *impl);
342 
343 /* EVP_VerifyInit is a deprecated version of |EVP_VerifyInit_ex|.
344  *
345  * TODO(fork): remove. */
346 OPENSSL_EXPORT int EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type);
347 
348 /* EVP_VerifyUpdate appends |len| bytes from |data| to the data which will be
349  * signed in |EVP_VerifyFinal|. */
350 OPENSSL_EXPORT int EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *data,
351                                     size_t len);
352 
353 /* EVP_VerifyFinal verifies that |sig_len| bytes of |sig| are a valid
354  * signature, by |pkey|, for the data that has been included by one or more
355  * calls to |EVP_VerifyUpdate|.
356  *
357  * It returns one on success and zero otherwise.
358  *
359  * It does not modify |ctx|, thus it's possible to continue to use |ctx| in
360  * order to sign a longer message. */
361 OPENSSL_EXPORT int EVP_VerifyFinal(EVP_MD_CTX *ctx, const uint8_t *sig,
362                                    size_t sig_len, EVP_PKEY *pkey);
363 
364 
365 /* Printing */
366 
367 /* EVP_PKEY_print_public prints a textual representation of the public key in
368  * |pkey| to |out|. Returns one on success or zero otherwise. */
369 OPENSSL_EXPORT int EVP_PKEY_print_public(BIO *out, const EVP_PKEY *pkey,
370                                          int indent, ASN1_PCTX *pctx);
371 
372 /* EVP_PKEY_print_private prints a textual representation of the private key in
373  * |pkey| to |out|. Returns one on success or zero otherwise. */
374 OPENSSL_EXPORT int EVP_PKEY_print_private(BIO *out, const EVP_PKEY *pkey,
375                                           int indent, ASN1_PCTX *pctx);
376 
377 /* EVP_PKEY_print_params prints a textual representation of the parameters in
378  * |pkey| to |out|. Returns one on success or zero otherwise. */
379 OPENSSL_EXPORT int EVP_PKEY_print_params(BIO *out, const EVP_PKEY *pkey,
380                                          int indent, ASN1_PCTX *pctx);
381 
382 
383 /* Password stretching.
384  *
385  * Password stretching functions take a low-entropy password and apply a slow
386  * function that results in a key suitable for use in symmetric
387  * cryptography. */
388 
389 /* PKCS5_PBKDF2_HMAC computes |iterations| iterations of PBKDF2 of |password|
390  * and |salt|, using |digest|, and outputs |key_len| bytes to |out_key|. It
391  * returns one on success and zero on error. */
392 OPENSSL_EXPORT int PKCS5_PBKDF2_HMAC(const char *password, size_t password_len,
393                                      const uint8_t *salt, size_t salt_len,
394                                      unsigned iterations, const EVP_MD *digest,
395                                      size_t key_len, uint8_t *out_key);
396 
397 /* PKCS5_PBKDF2_HMAC_SHA1 is the same as PKCS5_PBKDF2_HMAC, but with |digest|
398  * fixed to |EVP_sha1|. */
399 OPENSSL_EXPORT int PKCS5_PBKDF2_HMAC_SHA1(const char *password,
400                                           size_t password_len, const uint8_t *salt,
401                                           size_t salt_len, unsigned iterations,
402                                           size_t key_len, uint8_t *out_key);
403 
404 
405 /* Public key contexts.
406  *
407  * |EVP_PKEY_CTX| objects hold the context of an operation (e.g. signing or
408  * encrypting) that uses a public key. */
409 
410 /* EVP_PKEY_CTX_new allocates a fresh |EVP_PKEY_CTX| for use with |pkey|. It
411  * returns the context or NULL on error. */
412 OPENSSL_EXPORT EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e);
413 
414 /* EVP_PKEY_CTX_new_id allocates a fresh |EVP_PKEY_CTX| for a key of type |id|
415  * (e.g. |EVP_PKEY_HMAC|). This can be used for key generation where
416  * |EVP_PKEY_CTX_new| can't be used because there isn't an |EVP_PKEY| to pass
417  * it. It returns the context or NULL on error. */
418 OPENSSL_EXPORT EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e);
419 
420 /* EVP_PKEY_CTX_free frees |ctx| and the data it owns. */
421 OPENSSL_EXPORT void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx);
422 
423 /* EVP_PKEY_CTX_dup allocates a fresh |EVP_PKEY_CTX| and sets it equal to the
424  * state of |ctx|. It returns the fresh |EVP_PKEY_CTX| or NULL on error. */
425 OPENSSL_EXPORT EVP_PKEY_CTX *EVP_PKEY_CTX_dup(EVP_PKEY_CTX *ctx);
426 
427 /* EVP_PKEY_CTX_get0_pkey returns the |EVP_PKEY| associated with |ctx|. */
428 OPENSSL_EXPORT EVP_PKEY *EVP_PKEY_CTX_get0_pkey(EVP_PKEY_CTX *ctx);
429 
430 /* EVP_PKEY_CTX_set_app_data sets an opaque pointer on |ctx|. */
431 OPENSSL_EXPORT void EVP_PKEY_CTX_set_app_data(EVP_PKEY_CTX *ctx, void *data);
432 
433 /* EVP_PKEY_CTX_get_app_data returns the opaque pointer from |ctx| that was
434  * previously set with |EVP_PKEY_CTX_set_app_data|, or NULL if none has been
435  * set. */
436 OPENSSL_EXPORT void *EVP_PKEY_CTX_get_app_data(EVP_PKEY_CTX *ctx);
437 
438 /* EVP_PKEY_sign_init initialises an |EVP_PKEY_CTX| for a signing operation. It
439  * should be called before |EVP_PKEY_sign|.
440  *
441  * It returns one on success or zero on error. */
442 OPENSSL_EXPORT int EVP_PKEY_sign_init(EVP_PKEY_CTX *ctx);
443 
444 /* EVP_PKEY_sign signs |data_len| bytes from |data| using |ctx|. If |sig| is
445  * NULL, the maximum size of the signature is written to
446  * |out_sig_len|. Otherwise, |*sig_len| must contain the number of bytes of
447  * space available at |sig|. If sufficient, the signature will be written to
448  * |sig| and |*sig_len| updated with the true length.
449  *
450  * WARNING: Setting |sig| to NULL only gives the maximum size of the
451  * signature. The actual signature may be smaller.
452  *
453  * It returns one on success or zero on error. (Note: this differs from
454  * OpenSSL, which can also return negative values to indicate an error. ) */
455 OPENSSL_EXPORT int EVP_PKEY_sign(EVP_PKEY_CTX *ctx, uint8_t *sig,
456                                  size_t *sig_len, const uint8_t *data,
457                                  size_t data_len);
458 
459 /* EVP_PKEY_verify_init initialises an |EVP_PKEY_CTX| for a signature
460  * verification operation. It should be called before |EVP_PKEY_verify|.
461  *
462  * It returns one on success or zero on error. */
463 OPENSSL_EXPORT int EVP_PKEY_verify_init(EVP_PKEY_CTX *ctx);
464 
465 /* EVP_PKEY_verify verifies that |sig_len| bytes from |sig| are a valid signature
466  * for |data|.
467  *
468  * It returns one on success or zero on error. */
469 OPENSSL_EXPORT int EVP_PKEY_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig,
470                                    size_t sig_len, const uint8_t *data,
471                                    size_t data_len);
472 
473 /* EVP_PKEY_encrypt_init initialises an |EVP_PKEY_CTX| for an encryption
474  * operation. It should be called before |EVP_PKEY_encrypt|.
475  *
476  * It returns one on success or zero on error. */
477 OPENSSL_EXPORT int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx);
478 
479 /* EVP_PKEY_encrypt encrypts |in_len| bytes from |in|. If |out| is NULL, the
480  * maximum size of the ciphertext is written to |out_len|. Otherwise, |*out_len|
481  * must contain the number of bytes of space available at |out|. If sufficient,
482  * the ciphertext will be written to |out| and |*out_len| updated with the true
483  * length.
484  *
485  * WARNING: Setting |out| to NULL only gives the maximum size of the
486  * ciphertext. The actual ciphertext may be smaller.
487  *
488  * It returns one on success or zero on error. */
489 OPENSSL_EXPORT int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, uint8_t *out,
490                                     size_t *out_len, const uint8_t *in,
491                                     size_t in_len);
492 
493 /* EVP_PKEY_decrypt_init initialises an |EVP_PKEY_CTX| for a decryption
494  * operation. It should be called before |EVP_PKEY_decrypt|.
495  *
496  * It returns one on success or zero on error. */
497 OPENSSL_EXPORT int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx);
498 
499 /* EVP_PKEY_decrypt decrypts |in_len| bytes from |in|. If |out| is NULL, the
500  * maximum size of the plaintext is written to |out_len|. Otherwise, |*out_len|
501  * must contain the number of bytes of space available at |out|. If sufficient,
502  * the ciphertext will be written to |out| and |*out_len| updated with the true
503  * length.
504  *
505  * WARNING: Setting |out| to NULL only gives the maximum size of the
506  * plaintext. The actual plaintext may be smaller.
507  *
508  * It returns one on success or zero on error. */
509 OPENSSL_EXPORT int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx, uint8_t *out,
510                                     size_t *out_len, const uint8_t *in,
511                                     size_t in_len);
512 
513 /* EVP_PKEY_derive_init initialises an |EVP_PKEY_CTX| for a key derivation
514  * operation. It should be called before |EVP_PKEY_derive_set_peer| and
515  * |EVP_PKEY_derive|.
516  *
517  * It returns one on success or zero on error. */
518 OPENSSL_EXPORT int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx);
519 
520 /* EVP_PKEY_derive_set_peer sets the peer's key to be used for key derivation
521  * by |ctx| to |peer|. It should be called after |EVP_PKEY_derive_init|. (For
522  * example, this is used to set the peer's key in (EC)DH.) It returns one on
523  * success and zero on error. */
524 OPENSSL_EXPORT int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer);
525 
526 /* EVP_PKEY_derive derives a shared key between the two keys configured in
527  * |ctx|. If |key| is non-NULL then, on entry, |out_key_len| must contain the
528  * amount of space at |key|. If sufficient then the shared key will be written
529  * to |key| and |*out_key_len| will be set to the length. If |key| is NULL then
530  * |out_key_len| will be set to the maximum length.
531  *
532  * WARNING: Setting |out| to NULL only gives the maximum size of the key. The
533  * actual key may be smaller.
534  *
535  * It returns one on success and zero on error. */
536 OPENSSL_EXPORT int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, uint8_t *key,
537                                    size_t *out_key_len);
538 
539 /* EVP_PKEY_keygen_init initialises an |EVP_PKEY_CTX| for a key generation
540  * operation. It should be called before |EVP_PKEY_keygen|.
541  *
542  * It returns one on success or zero on error. */
543 OPENSSL_EXPORT int EVP_PKEY_keygen_init(EVP_PKEY_CTX *ctx);
544 
545 /* EVP_PKEY_keygen performs a key generation operation using the values from
546  * |ctx| and sets |*ppkey| to a fresh |EVP_PKEY| containing the resulting key.
547  * It returns one on success or zero on error. */
548 OPENSSL_EXPORT int EVP_PKEY_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey);
549 
550 
551 /* Generic control functions. */
552 
553 /* EVP_PKEY_CTX_set_signature_md sets |md| as the digest to be used in a
554  * signature operation. It returns one on success or zero on error. */
555 OPENSSL_EXPORT int EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx,
556                                                  const EVP_MD *md);
557 
558 /* EVP_PKEY_CTX_get_signature_md sets |*out_md| to the digest to be used in a
559  * signature operation. It returns one on success or zero on error. */
560 OPENSSL_EXPORT int EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx,
561                                                  const EVP_MD **out_md);
562 
563 
564 /* RSA specific control functions. */
565 
566 /* EVP_PKEY_CTX_set_rsa_padding sets the padding type to use. It should be one
567  * of the |RSA_*_PADDING| values. Returns one on success or zero on error. */
568 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int padding);
569 
570 /* EVP_PKEY_CTX_get_rsa_padding sets |*out_padding| to the current padding
571  * value, which is one of the |RSA_*_PADDING| values. Returns one on success or
572  * zero on error. */
573 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_padding(EVP_PKEY_CTX *ctx,
574                                                 int *out_padding);
575 
576 /* EVP_PKEY_CTX_set_rsa_pss_saltlen sets the length of the salt in a PSS-padded
577  * signature. A value of -1 cause the salt to be the same length as the digest
578  * in the signature. A value of -2 causes the salt to be the maximum length
579  * that will fit. Otherwise the value gives the size of the salt in bytes.
580  *
581  * Returns one on success or zero on error. */
582 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx,
583                                                     int salt_len);
584 
585 /* EVP_PKEY_CTX_get_rsa_pss_saltlen sets |*out_salt_len| to the salt length of
586  * a PSS-padded signature. See the documentation for
587  * |EVP_PKEY_CTX_set_rsa_pss_saltlen| for details of the special values that it
588  * can take.
589  *
590  * Returns one on success or zero on error. */
591 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_pss_saltlen(EVP_PKEY_CTX *ctx,
592                                                     int *out_salt_len);
593 
594 /* EVP_PKEY_CTX_set_rsa_keygen_bits sets the size of the desired RSA modulus,
595  * in bits, for key generation. Returns one on success or zero on
596  * error. */
597 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_keygen_bits(EVP_PKEY_CTX *ctx,
598                                                     int bits);
599 
600 /* EVP_PKEY_CTX_set_rsa_keygen_pubexp sets |e| as the public exponent for key
601  * generation. Returns one on success or zero on error. */
602 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx,
603                                                       BIGNUM *e);
604 
605 /* EVP_PKEY_CTX_set_rsa_oaep_md sets |md| as the digest used in OAEP padding.
606  * Returns one on success or zero on error. */
607 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_oaep_md(EVP_PKEY_CTX *ctx,
608                                                 const EVP_MD *md);
609 
610 /* EVP_PKEY_CTX_get_rsa_oaep_md sets |*out_md| to the digest function used in
611  * OAEP padding. Returns one on success or zero on error. */
612 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_oaep_md(EVP_PKEY_CTX *ctx,
613                                                 const EVP_MD **out_md);
614 
615 /* EVP_PKEY_CTX_set_rsa_mgf1_md sets |md| as the digest used in MGF1. Returns
616  * one on success or zero on error. */
617 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_mgf1_md(EVP_PKEY_CTX *ctx,
618                                                 const EVP_MD *md);
619 
620 /* EVP_PKEY_CTX_get_rsa_mgf1_md sets |*out_md| to the digest function used in
621  * MGF1. Returns one on success or zero on error. */
622 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_mgf1_md(EVP_PKEY_CTX *ctx,
623                                                 const EVP_MD **out_md);
624 
625 /* EVP_PKEY_CTX_set0_rsa_oaep_label sets |label_len| bytes from |label| as the
626  * label used in OAEP. DANGER: On success, this call takes ownership of |label|
627  * and will call |OPENSSL_free| on it when |ctx| is destroyed.
628  *
629  * Returns one on success or zero on error. */
630 OPENSSL_EXPORT int EVP_PKEY_CTX_set0_rsa_oaep_label(EVP_PKEY_CTX *ctx,
631                                                     const uint8_t *label,
632                                                     size_t label_len);
633 
634 /* EVP_PKEY_CTX_get0_rsa_oaep_label sets |*out_label| to point to the internal
635  * buffer containing the OAEP label (which may be NULL) and returns the length
636  * of the label or a negative value on error.
637  *
638  * WARNING: the return value differs from the usual return value convention. */
639 OPENSSL_EXPORT int EVP_PKEY_CTX_get0_rsa_oaep_label(EVP_PKEY_CTX *ctx,
640                                                     const uint8_t **out_label);
641 
642 
643 /* Deprecated functions. */
644 
645 /* EVP_PKEY_DH is defined for compatibility, but it is impossible to create an
646  * |EVP_PKEY| of that type. */
647 #define EVP_PKEY_DH NID_dhKeyAgreement
648 
649 /* OpenSSL_add_all_algorithms does nothing. */
650 OPENSSL_EXPORT void OpenSSL_add_all_algorithms(void);
651 
652 /* OpenSSL_add_all_ciphers does nothing. */
653 OPENSSL_EXPORT void OpenSSL_add_all_ciphers(void);
654 
655 /* OpenSSL_add_all_digests does nothing. */
656 OPENSSL_EXPORT void OpenSSL_add_all_digests(void);
657 
658 /* EVP_cleanup does nothing. */
659 OPENSSL_EXPORT void EVP_cleanup(void);
660 
661 
662 /* Private functions */
663 
664 /* EVP_PKEY_asn1_find returns the ASN.1 method table for the given |nid|, which
665  * should be one of the |EVP_PKEY_*| values. It returns NULL if |nid| is
666  * unknown. */
667 OPENSSL_EXPORT const EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_find(ENGINE **pengine,
668                                                               int nid);
669 
670 /* EVP_PKEY_asn1_find_str returns an |EVP_PKEY_ASN1_METHOD| by matching values
671  * of the |len| bytes at |name|. For example, if name equals "EC" then it will
672  * return an ECC method. The |pengine| argument is ignored.
673  *
674  * TODO(fork): move to PEM? */
675 OPENSSL_EXPORT const EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_find_str(
676     ENGINE **pengine, const char *name, size_t len);
677 
678 struct evp_pkey_st {
679   CRYPTO_refcount_t references;
680 
681   /* type contains one of the EVP_PKEY_* values or NID_undef and determines
682    * which element (if any) of the |pkey| union is valid. */
683   int type;
684 
685   union {
686     char *ptr;
687     RSA *rsa;
688     DSA *dsa;
689     DH *dh;
690     EC_KEY *ec;
691   } pkey;
692 
693   /* ameth contains a pointer to a method table that contains many ASN.1
694    * methods for the key type. */
695   const EVP_PKEY_ASN1_METHOD *ameth;
696 } /* EVP_PKEY */;
697 
698 
699 #if defined(__cplusplus)
700 }  /* extern C */
701 #endif
702 
703 #define EVP_R_BUFFER_TOO_SMALL 100
704 #define EVP_R_COMMAND_NOT_SUPPORTED 101
705 #define EVP_R_DIFFERENT_KEY_TYPES 104
706 #define EVP_R_DIFFERENT_PARAMETERS 105
707 #define EVP_R_EXPECTING_AN_EC_KEY_KEY 107
708 #define EVP_R_EXPECTING_A_DH_KEY 109
709 #define EVP_R_EXPECTING_A_DSA_KEY 110
710 #define EVP_R_ILLEGAL_OR_UNSUPPORTED_PADDING_MODE 111
711 #define EVP_R_INVALID_CURVE 112
712 #define EVP_R_INVALID_DIGEST_LENGTH 113
713 #define EVP_R_INVALID_DIGEST_TYPE 114
714 #define EVP_R_INVALID_KEYBITS 115
715 #define EVP_R_INVALID_MGF1_MD 116
716 #define EVP_R_INVALID_PADDING_MODE 118
717 #define EVP_R_INVALID_PSS_PARAMETERS 119
718 #define EVP_R_INVALID_SALT_LENGTH 121
719 #define EVP_R_INVALID_TRAILER 122
720 #define EVP_R_KEYS_NOT_SET 123
721 #define EVP_R_MISSING_PARAMETERS 124
722 #define EVP_R_NO_DEFAULT_DIGEST 125
723 #define EVP_R_NO_KEY_SET 126
724 #define EVP_R_NO_MDC2_SUPPORT 127
725 #define EVP_R_NO_NID_FOR_CURVE 128
726 #define EVP_R_NO_OPERATION_SET 129
727 #define EVP_R_NO_PARAMETERS_SET 130
728 #define EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE 131
729 #define EVP_R_OPERATON_NOT_INITIALIZED 132
730 #define EVP_R_UNKNOWN_DIGEST 133
731 #define EVP_R_UNKNOWN_MASK_DIGEST 134
732 #define EVP_R_UNSUPPORTED_ALGORITHM 138
733 #define EVP_R_UNSUPPORTED_MASK_ALGORITHM 139
734 #define EVP_R_UNSUPPORTED_MASK_PARAMETER 140
735 #define EVP_R_EXPECTING_AN_RSA_KEY 141
736 #define EVP_R_INVALID_OPERATION 142
737 #define EVP_R_DECODE_ERROR 143
738 #define EVP_R_INVALID_PSS_SALTLEN 144
739 #define EVP_R_UNKNOWN_PUBLIC_KEY_TYPE 145
740 #define EVP_R_CONTEXT_NOT_INITIALISED 146
741 #define EVP_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED 147
742 #define EVP_R_WRONG_PUBLIC_KEY_TYPE 148
743 #define EVP_R_UNKNOWN_SIGNATURE_ALGORITHM 149
744 #define EVP_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM 150
745 #define EVP_R_BN_DECODE_ERROR 151
746 #define EVP_R_PARAMETER_ENCODING_ERROR 152
747 #define EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE 153
748 #define EVP_R_UNSUPPORTED_SIGNATURE_TYPE 154
749 
750 #endif  /* OPENSSL_HEADER_EVP_H */
751