Home | History | Annotate | Download | only in openssl
      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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/nid.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 one. */
     93 OPENSSL_EXPORT int 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 |nid| if |nid| is a known key type and |NID_undef|
    137  * otherwise. */
    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_DSA NID_dsa
    169 #define EVP_PKEY_EC NID_X9_62_id_ecPublicKey
    170 
    171 /* EVP_PKEY_assign sets the underlying key of |pkey| to |key|, which must be of
    172  * the given type. The |type| argument should be one of the |EVP_PKEY_*|
    173  * values. */
    174 OPENSSL_EXPORT int EVP_PKEY_assign(EVP_PKEY *pkey, int type, void *key);
    175 
    176 /* EVP_PKEY_set_type sets the type of |pkey| to |type|, which should be one of
    177  * the |EVP_PKEY_*| values. It returns one if successful or zero otherwise. If
    178  * |pkey| is NULL, it simply reports whether the type is known. */
    179 OPENSSL_EXPORT int EVP_PKEY_set_type(EVP_PKEY *pkey, int type);
    180 
    181 /* EVP_PKEY_cmp_parameters compares the parameters of |a| and |b|. It returns
    182  * one if they match, zero if not, or a negative number of on error.
    183  *
    184  * WARNING: the return value differs from the usual return value convention. */
    185 OPENSSL_EXPORT int EVP_PKEY_cmp_parameters(const EVP_PKEY *a,
    186                                            const EVP_PKEY *b);
    187 
    188 
    189 /* ASN.1 functions */
    190 
    191 /* EVP_parse_public_key decodes a DER-encoded SubjectPublicKeyInfo structure
    192  * (RFC 5280) from |cbs| and advances |cbs|. It returns a newly-allocated
    193  * |EVP_PKEY| or NULL on error.
    194  *
    195  * The caller must check the type of the parsed public key to ensure it is
    196  * suitable and validate other desired key properties such as RSA modulus size
    197  * or EC curve. */
    198 OPENSSL_EXPORT EVP_PKEY *EVP_parse_public_key(CBS *cbs);
    199 
    200 /* EVP_marshal_public_key marshals |key| as a DER-encoded SubjectPublicKeyInfo
    201  * structure (RFC 5280) and appends the result to |cbb|. It returns one on
    202  * success and zero on error. */
    203 OPENSSL_EXPORT int EVP_marshal_public_key(CBB *cbb, const EVP_PKEY *key);
    204 
    205 /* EVP_parse_private_key decodes a DER-encoded PrivateKeyInfo structure (RFC
    206  * 5208) from |cbs| and advances |cbs|. It returns a newly-allocated |EVP_PKEY|
    207  * or NULL on error.
    208  *
    209  * The caller must check the type of the parsed private key to ensure it is
    210  * suitable and validate other desired key properties such as RSA modulus size
    211  * or EC curve.
    212  *
    213  * A PrivateKeyInfo ends with an optional set of attributes. These are not
    214  * processed and so this function will silently ignore any trailing data in the
    215  * structure. */
    216 OPENSSL_EXPORT EVP_PKEY *EVP_parse_private_key(CBS *cbs);
    217 
    218 /* EVP_marshal_private_key marshals |key| as a DER-encoded PrivateKeyInfo
    219  * structure (RFC 5208) and appends the result to |cbb|. It returns one on
    220  * success and zero on error. */
    221 OPENSSL_EXPORT int EVP_marshal_private_key(CBB *cbb, const EVP_PKEY *key);
    222 
    223 
    224 /* Signing */
    225 
    226 /* EVP_DigestSignInit sets up |ctx| for a signing operation with |type| and
    227  * |pkey|. The |ctx| argument must have been initialised with
    228  * |EVP_MD_CTX_init|. If |pctx| is not NULL, the |EVP_PKEY_CTX| of the signing
    229  * operation will be written to |*pctx|; this can be used to set alternative
    230  * signing options.
    231  *
    232  * It returns one on success, or zero on error. */
    233 OPENSSL_EXPORT int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
    234                                       const EVP_MD *type, ENGINE *e,
    235                                       EVP_PKEY *pkey);
    236 
    237 /* EVP_DigestSignUpdate appends |len| bytes from |data| to the data which will
    238  * be signed in |EVP_DigestSignFinal|. It returns one. */
    239 OPENSSL_EXPORT int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *data,
    240                                         size_t len);
    241 
    242 /* EVP_DigestSignFinal signs the data that has been included by one or more
    243  * calls to |EVP_DigestSignUpdate|. If |out_sig| is NULL then |*out_sig_len| is
    244  * set to the maximum number of output bytes. Otherwise, on entry,
    245  * |*out_sig_len| must contain the length of the |out_sig| buffer. If the call
    246  * is successful, the signature is written to |out_sig| and |*out_sig_len| is
    247  * set to its length.
    248  *
    249  * It returns one on success, or zero on error. */
    250 OPENSSL_EXPORT int EVP_DigestSignFinal(EVP_MD_CTX *ctx, uint8_t *out_sig,
    251                                        size_t *out_sig_len);
    252 
    253 
    254 /* Verifying */
    255 
    256 /* EVP_DigestVerifyInit sets up |ctx| for a signature verification operation
    257  * with |type| and |pkey|. The |ctx| argument must have been initialised with
    258  * |EVP_MD_CTX_init|. If |pctx| is not NULL, the |EVP_PKEY_CTX| of the signing
    259  * operation will be written to |*pctx|; this can be used to set alternative
    260  * signing options.
    261  *
    262  * It returns one on success, or zero on error. */
    263 OPENSSL_EXPORT int EVP_DigestVerifyInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
    264                                         const EVP_MD *type, ENGINE *e,
    265                                         EVP_PKEY *pkey);
    266 
    267 /* EVP_DigestVerifyUpdate appends |len| bytes from |data| to the data which
    268  * will be verified by |EVP_DigestVerifyFinal|. It returns one. */
    269 OPENSSL_EXPORT int EVP_DigestVerifyUpdate(EVP_MD_CTX *ctx, const void *data,
    270                                           size_t len);
    271 
    272 /* EVP_DigestVerifyFinal verifies that |sig_len| bytes of |sig| are a valid
    273  * signature for the data that has been included by one or more calls to
    274  * |EVP_DigestVerifyUpdate|. It returns one on success and zero otherwise. */
    275 OPENSSL_EXPORT int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const uint8_t *sig,
    276                                          size_t sig_len);
    277 
    278 
    279 /* Signing (old functions) */
    280 
    281 /* EVP_SignInit_ex configures |ctx|, which must already have been initialised,
    282  * for a fresh signing operation using the hash function |type|. It returns one
    283  * on success and zero otherwise.
    284  *
    285  * (In order to initialise |ctx|, either obtain it initialised with
    286  * |EVP_MD_CTX_create|, or use |EVP_MD_CTX_init|.) */
    287 OPENSSL_EXPORT int EVP_SignInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type,
    288                                    ENGINE *impl);
    289 
    290 /* EVP_SignInit is a deprecated version of |EVP_SignInit_ex|.
    291  *
    292  * TODO(fork): remove. */
    293 OPENSSL_EXPORT int EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type);
    294 
    295 /* EVP_SignUpdate appends |len| bytes from |data| to the data which will be
    296  * signed in |EVP_SignFinal|. */
    297 OPENSSL_EXPORT int EVP_SignUpdate(EVP_MD_CTX *ctx, const void *data,
    298                                   size_t len);
    299 
    300 /* EVP_SignFinal signs the data that has been included by one or more calls to
    301  * |EVP_SignUpdate|, using the key |pkey|, and writes it to |sig|. On entry,
    302  * |sig| must point to at least |EVP_PKEY_size(pkey)| bytes of space. The
    303  * actual size of the signature is written to |*out_sig_len|.
    304  *
    305  * It returns one on success and zero otherwise.
    306  *
    307  * It does not modify |ctx|, thus it's possible to continue to use |ctx| in
    308  * order to sign a longer message. */
    309 OPENSSL_EXPORT int EVP_SignFinal(const EVP_MD_CTX *ctx, uint8_t *sig,
    310                                  unsigned int *out_sig_len, EVP_PKEY *pkey);
    311 
    312 
    313 /* Verifying (old functions) */
    314 
    315 /* EVP_VerifyInit_ex configures |ctx|, which must already have been
    316  * initialised, for a fresh signature verification operation using the hash
    317  * function |type|. It returns one on success and zero otherwise.
    318  *
    319  * (In order to initialise |ctx|, either obtain it initialised with
    320  * |EVP_MD_CTX_create|, or use |EVP_MD_CTX_init|.) */
    321 OPENSSL_EXPORT int EVP_VerifyInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type,
    322                                      ENGINE *impl);
    323 
    324 /* EVP_VerifyInit is a deprecated version of |EVP_VerifyInit_ex|.
    325  *
    326  * TODO(fork): remove. */
    327 OPENSSL_EXPORT int EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type);
    328 
    329 /* EVP_VerifyUpdate appends |len| bytes from |data| to the data which will be
    330  * signed in |EVP_VerifyFinal|. */
    331 OPENSSL_EXPORT int EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *data,
    332                                     size_t len);
    333 
    334 /* EVP_VerifyFinal verifies that |sig_len| bytes of |sig| are a valid
    335  * signature, by |pkey|, for the data that has been included by one or more
    336  * calls to |EVP_VerifyUpdate|.
    337  *
    338  * It returns one on success and zero otherwise.
    339  *
    340  * It does not modify |ctx|, thus it's possible to continue to use |ctx| in
    341  * order to sign a longer message. */
    342 OPENSSL_EXPORT int EVP_VerifyFinal(EVP_MD_CTX *ctx, const uint8_t *sig,
    343                                    size_t sig_len, EVP_PKEY *pkey);
    344 
    345 
    346 /* Printing */
    347 
    348 /* EVP_PKEY_print_public prints a textual representation of the public key in
    349  * |pkey| to |out|. Returns one on success or zero otherwise. */
    350 OPENSSL_EXPORT int EVP_PKEY_print_public(BIO *out, const EVP_PKEY *pkey,
    351                                          int indent, ASN1_PCTX *pctx);
    352 
    353 /* EVP_PKEY_print_private prints a textual representation of the private key in
    354  * |pkey| to |out|. Returns one on success or zero otherwise. */
    355 OPENSSL_EXPORT int EVP_PKEY_print_private(BIO *out, const EVP_PKEY *pkey,
    356                                           int indent, ASN1_PCTX *pctx);
    357 
    358 /* EVP_PKEY_print_params prints a textual representation of the parameters in
    359  * |pkey| to |out|. Returns one on success or zero otherwise. */
    360 OPENSSL_EXPORT int EVP_PKEY_print_params(BIO *out, const EVP_PKEY *pkey,
    361                                          int indent, ASN1_PCTX *pctx);
    362 
    363 
    364 /* Password stretching.
    365  *
    366  * Password stretching functions take a low-entropy password and apply a slow
    367  * function that results in a key suitable for use in symmetric
    368  * cryptography. */
    369 
    370 /* PKCS5_PBKDF2_HMAC computes |iterations| iterations of PBKDF2 of |password|
    371  * and |salt|, using |digest|, and outputs |key_len| bytes to |out_key|. It
    372  * returns one on success and zero on error. */
    373 OPENSSL_EXPORT int PKCS5_PBKDF2_HMAC(const char *password, size_t password_len,
    374                                      const uint8_t *salt, size_t salt_len,
    375                                      unsigned iterations, const EVP_MD *digest,
    376                                      size_t key_len, uint8_t *out_key);
    377 
    378 /* PKCS5_PBKDF2_HMAC_SHA1 is the same as PKCS5_PBKDF2_HMAC, but with |digest|
    379  * fixed to |EVP_sha1|. */
    380 OPENSSL_EXPORT int PKCS5_PBKDF2_HMAC_SHA1(const char *password,
    381                                           size_t password_len,
    382                                           const uint8_t *salt, size_t salt_len,
    383                                           unsigned iterations, size_t key_len,
    384                                           uint8_t *out_key);
    385 
    386 
    387 /* Public key contexts.
    388  *
    389  * |EVP_PKEY_CTX| objects hold the context of an operation (e.g. signing or
    390  * encrypting) that uses a public key. */
    391 
    392 /* EVP_PKEY_CTX_new allocates a fresh |EVP_PKEY_CTX| for use with |pkey|. It
    393  * returns the context or NULL on error. */
    394 OPENSSL_EXPORT EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e);
    395 
    396 /* EVP_PKEY_CTX_new_id allocates a fresh |EVP_PKEY_CTX| for a key of type |id|
    397  * (e.g. |EVP_PKEY_HMAC|). This can be used for key generation where
    398  * |EVP_PKEY_CTX_new| can't be used because there isn't an |EVP_PKEY| to pass
    399  * it. It returns the context or NULL on error. */
    400 OPENSSL_EXPORT EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e);
    401 
    402 /* EVP_PKEY_CTX_free frees |ctx| and the data it owns. */
    403 OPENSSL_EXPORT void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx);
    404 
    405 /* EVP_PKEY_CTX_dup allocates a fresh |EVP_PKEY_CTX| and sets it equal to the
    406  * state of |ctx|. It returns the fresh |EVP_PKEY_CTX| or NULL on error. */
    407 OPENSSL_EXPORT EVP_PKEY_CTX *EVP_PKEY_CTX_dup(EVP_PKEY_CTX *ctx);
    408 
    409 /* EVP_PKEY_CTX_get0_pkey returns the |EVP_PKEY| associated with |ctx|. */
    410 OPENSSL_EXPORT EVP_PKEY *EVP_PKEY_CTX_get0_pkey(EVP_PKEY_CTX *ctx);
    411 
    412 /* EVP_PKEY_sign_init initialises an |EVP_PKEY_CTX| for a signing operation. It
    413  * should be called before |EVP_PKEY_sign|.
    414  *
    415  * It returns one on success or zero on error. */
    416 OPENSSL_EXPORT int EVP_PKEY_sign_init(EVP_PKEY_CTX *ctx);
    417 
    418 /* EVP_PKEY_sign signs |data_len| bytes from |data| using |ctx|. If |sig| is
    419  * NULL, the maximum size of the signature is written to
    420  * |out_sig_len|. Otherwise, |*sig_len| must contain the number of bytes of
    421  * space available at |sig|. If sufficient, the signature will be written to
    422  * |sig| and |*sig_len| updated with the true length.
    423  *
    424  * WARNING: Setting |sig| to NULL only gives the maximum size of the
    425  * signature. The actual signature may be smaller.
    426  *
    427  * It returns one on success or zero on error. (Note: this differs from
    428  * OpenSSL, which can also return negative values to indicate an error. ) */
    429 OPENSSL_EXPORT int EVP_PKEY_sign(EVP_PKEY_CTX *ctx, uint8_t *sig,
    430                                  size_t *sig_len, const uint8_t *data,
    431                                  size_t data_len);
    432 
    433 /* EVP_PKEY_verify_init initialises an |EVP_PKEY_CTX| for a signature
    434  * verification operation. It should be called before |EVP_PKEY_verify|.
    435  *
    436  * It returns one on success or zero on error. */
    437 OPENSSL_EXPORT int EVP_PKEY_verify_init(EVP_PKEY_CTX *ctx);
    438 
    439 /* EVP_PKEY_verify verifies that |sig_len| bytes from |sig| are a valid
    440  * signature for |data|.
    441  *
    442  * It returns one on success or zero on error. */
    443 OPENSSL_EXPORT int EVP_PKEY_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig,
    444                                    size_t sig_len, const uint8_t *data,
    445                                    size_t data_len);
    446 
    447 /* EVP_PKEY_encrypt_init initialises an |EVP_PKEY_CTX| for an encryption
    448  * operation. It should be called before |EVP_PKEY_encrypt|.
    449  *
    450  * It returns one on success or zero on error. */
    451 OPENSSL_EXPORT int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx);
    452 
    453 /* EVP_PKEY_encrypt encrypts |in_len| bytes from |in|. If |out| is NULL, the
    454  * maximum size of the ciphertext is written to |out_len|. Otherwise, |*out_len|
    455  * must contain the number of bytes of space available at |out|. If sufficient,
    456  * the ciphertext will be written to |out| and |*out_len| updated with the true
    457  * length.
    458  *
    459  * WARNING: Setting |out| to NULL only gives the maximum size of the
    460  * ciphertext. The actual ciphertext may be smaller.
    461  *
    462  * It returns one on success or zero on error. */
    463 OPENSSL_EXPORT int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, uint8_t *out,
    464                                     size_t *out_len, const uint8_t *in,
    465                                     size_t in_len);
    466 
    467 /* EVP_PKEY_decrypt_init initialises an |EVP_PKEY_CTX| for a decryption
    468  * operation. It should be called before |EVP_PKEY_decrypt|.
    469  *
    470  * It returns one on success or zero on error. */
    471 OPENSSL_EXPORT int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx);
    472 
    473 /* EVP_PKEY_decrypt decrypts |in_len| bytes from |in|. If |out| is NULL, the
    474  * maximum size of the plaintext is written to |out_len|. Otherwise, |*out_len|
    475  * must contain the number of bytes of space available at |out|. If sufficient,
    476  * the ciphertext will be written to |out| and |*out_len| updated with the true
    477  * length.
    478  *
    479  * WARNING: Setting |out| to NULL only gives the maximum size of the
    480  * plaintext. The actual plaintext may be smaller.
    481  *
    482  * It returns one on success or zero on error. */
    483 OPENSSL_EXPORT int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx, uint8_t *out,
    484                                     size_t *out_len, const uint8_t *in,
    485                                     size_t in_len);
    486 
    487 /* EVP_PKEY_verify_recover_init initialises an |EVP_PKEY_CTX| for a public-key
    488  * decryption operation. It should be called before |EVP_PKEY_verify_recover|.
    489  *
    490  * Public-key decryption is a very obscure operation that is only implemented
    491  * by RSA keys. It is effectively a signature verification operation that
    492  * returns the signed message directly. It is almost certainly not what you
    493  * want.
    494  *
    495  * It returns one on success or zero on error. */
    496 OPENSSL_EXPORT int EVP_PKEY_verify_recover_init(EVP_PKEY_CTX *ctx);
    497 
    498 /* EVP_PKEY_verify_recover decrypts |sig_len| bytes from |sig|. If |out| is
    499  * NULL, the maximum size of the plaintext is written to |out_len|. Otherwise,
    500  * |*out_len| must contain the number of bytes of space available at |out|. If
    501  * sufficient, the ciphertext will be written to |out| and |*out_len| updated
    502  * with the true length.
    503  *
    504  * WARNING: Setting |out| to NULL only gives the maximum size of the
    505  * plaintext. The actual plaintext may be smaller.
    506  *
    507  * See the warning about this operation in |EVP_PKEY_verify_recover_init|. It
    508  * is probably not what you want.
    509  *
    510  * It returns one on success or zero on error. */
    511 OPENSSL_EXPORT int EVP_PKEY_verify_recover(EVP_PKEY_CTX *ctx, uint8_t *out,
    512                                            size_t *out_len, const uint8_t *sig,
    513                                            size_t siglen);
    514 
    515 /* EVP_PKEY_derive_init initialises an |EVP_PKEY_CTX| for a key derivation
    516  * operation. It should be called before |EVP_PKEY_derive_set_peer| and
    517  * |EVP_PKEY_derive|.
    518  *
    519  * It returns one on success or zero on error. */
    520 OPENSSL_EXPORT int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx);
    521 
    522 /* EVP_PKEY_derive_set_peer sets the peer's key to be used for key derivation
    523  * by |ctx| to |peer|. It should be called after |EVP_PKEY_derive_init|. (For
    524  * example, this is used to set the peer's key in (EC)DH.) It returns one on
    525  * success and zero on error. */
    526 OPENSSL_EXPORT int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer);
    527 
    528 /* EVP_PKEY_derive derives a shared key between the two keys configured in
    529  * |ctx|. If |key| is non-NULL then, on entry, |out_key_len| must contain the
    530  * amount of space at |key|. If sufficient then the shared key will be written
    531  * to |key| and |*out_key_len| will be set to the length. If |key| is NULL then
    532  * |out_key_len| will be set to the maximum length.
    533  *
    534  * WARNING: Setting |out| to NULL only gives the maximum size of the key. The
    535  * actual key may be smaller.
    536  *
    537  * It returns one on success and zero on error. */
    538 OPENSSL_EXPORT int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, uint8_t *key,
    539                                    size_t *out_key_len);
    540 
    541 /* EVP_PKEY_keygen_init initialises an |EVP_PKEY_CTX| for a key generation
    542  * operation. It should be called before |EVP_PKEY_keygen|.
    543  *
    544  * It returns one on success or zero on error. */
    545 OPENSSL_EXPORT int EVP_PKEY_keygen_init(EVP_PKEY_CTX *ctx);
    546 
    547 /* EVP_PKEY_keygen performs a key generation operation using the values from
    548  * |ctx| and sets |*ppkey| to a fresh |EVP_PKEY| containing the resulting key.
    549  * It returns one on success or zero on error. */
    550 OPENSSL_EXPORT int EVP_PKEY_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey);
    551 
    552 
    553 /* Generic control functions. */
    554 
    555 /* EVP_PKEY_CTX_set_signature_md sets |md| as the digest to be used in a
    556  * signature operation. It returns one on success or zero on error. */
    557 OPENSSL_EXPORT int EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx,
    558                                                  const EVP_MD *md);
    559 
    560 /* EVP_PKEY_CTX_get_signature_md sets |*out_md| to the digest to be used in a
    561  * signature operation. It returns one on success or zero on error. */
    562 OPENSSL_EXPORT int EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx,
    563                                                  const EVP_MD **out_md);
    564 
    565 
    566 /* RSA specific control functions. */
    567 
    568 /* EVP_PKEY_CTX_set_rsa_padding sets the padding type to use. It should be one
    569  * of the |RSA_*_PADDING| values. Returns one on success or zero on error. */
    570 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int padding);
    571 
    572 /* EVP_PKEY_CTX_get_rsa_padding sets |*out_padding| to the current padding
    573  * value, which is one of the |RSA_*_PADDING| values. Returns one on success or
    574  * zero on error. */
    575 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_padding(EVP_PKEY_CTX *ctx,
    576                                                 int *out_padding);
    577 
    578 /* EVP_PKEY_CTX_set_rsa_pss_saltlen sets the length of the salt in a PSS-padded
    579  * signature. A value of -1 cause the salt to be the same length as the digest
    580  * in the signature. A value of -2 causes the salt to be the maximum length
    581  * that will fit when signing and recovered from the signature when verifying.
    582  * Otherwise the value gives the size of the salt in bytes.
    583  *
    584  * If unsure, use -1.
    585  *
    586  * Returns one on success or zero on error. */
    587 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx,
    588                                                     int salt_len);
    589 
    590 /* EVP_PKEY_CTX_get_rsa_pss_saltlen sets |*out_salt_len| to the salt length of
    591  * a PSS-padded signature. See the documentation for
    592  * |EVP_PKEY_CTX_set_rsa_pss_saltlen| for details of the special values that it
    593  * can take.
    594  *
    595  * Returns one on success or zero on error. */
    596 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_pss_saltlen(EVP_PKEY_CTX *ctx,
    597                                                     int *out_salt_len);
    598 
    599 /* EVP_PKEY_CTX_set_rsa_keygen_bits sets the size of the desired RSA modulus,
    600  * in bits, for key generation. Returns one on success or zero on
    601  * error. */
    602 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_keygen_bits(EVP_PKEY_CTX *ctx,
    603                                                     int bits);
    604 
    605 /* EVP_PKEY_CTX_set_rsa_keygen_pubexp sets |e| as the public exponent for key
    606  * generation. Returns one on success or zero on error. */
    607 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx,
    608                                                       BIGNUM *e);
    609 
    610 /* EVP_PKEY_CTX_set_rsa_oaep_md sets |md| as the digest used in OAEP padding.
    611  * Returns one on success or zero on error. */
    612 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_oaep_md(EVP_PKEY_CTX *ctx,
    613                                                 const EVP_MD *md);
    614 
    615 /* EVP_PKEY_CTX_get_rsa_oaep_md sets |*out_md| to the digest function used in
    616  * OAEP padding. Returns one on success or zero on error. */
    617 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_oaep_md(EVP_PKEY_CTX *ctx,
    618                                                 const EVP_MD **out_md);
    619 
    620 /* EVP_PKEY_CTX_set_rsa_mgf1_md sets |md| as the digest used in MGF1. Returns
    621  * one on success or zero on error. */
    622 OPENSSL_EXPORT int EVP_PKEY_CTX_set_rsa_mgf1_md(EVP_PKEY_CTX *ctx,
    623                                                 const EVP_MD *md);
    624 
    625 /* EVP_PKEY_CTX_get_rsa_mgf1_md sets |*out_md| to the digest function used in
    626  * MGF1. Returns one on success or zero on error. */
    627 OPENSSL_EXPORT int EVP_PKEY_CTX_get_rsa_mgf1_md(EVP_PKEY_CTX *ctx,
    628                                                 const EVP_MD **out_md);
    629 
    630 /* EVP_PKEY_CTX_set0_rsa_oaep_label sets |label_len| bytes from |label| as the
    631  * label used in OAEP. DANGER: On success, this call takes ownership of |label|
    632  * and will call |OPENSSL_free| on it when |ctx| is destroyed.
    633  *
    634  * Returns one on success or zero on error. */
    635 OPENSSL_EXPORT int EVP_PKEY_CTX_set0_rsa_oaep_label(EVP_PKEY_CTX *ctx,
    636                                                     uint8_t *label,
    637                                                     size_t label_len);
    638 
    639 /* EVP_PKEY_CTX_get0_rsa_oaep_label sets |*out_label| to point to the internal
    640  * buffer containing the OAEP label (which may be NULL) and returns the length
    641  * of the label or a negative value on error.
    642  *
    643  * WARNING: the return value differs from the usual return value convention. */
    644 OPENSSL_EXPORT int EVP_PKEY_CTX_get0_rsa_oaep_label(EVP_PKEY_CTX *ctx,
    645                                                     const uint8_t **out_label);
    646 
    647 
    648 /* Deprecated functions. */
    649 
    650 /* EVP_PKEY_DH is defined for compatibility, but it is impossible to create an
    651  * |EVP_PKEY| of that type. */
    652 #define EVP_PKEY_DH NID_dhKeyAgreement
    653 
    654 /* EVP_PKEY_RSA2 was historically an alternate form for RSA public keys (OID
    655  * 2.5.8.1.1), but is no longer accepted. */
    656 #define EVP_PKEY_RSA2 NID_rsa
    657 
    658 /* OpenSSL_add_all_algorithms does nothing. */
    659 OPENSSL_EXPORT void OpenSSL_add_all_algorithms(void);
    660 
    661 /* OPENSSL_add_all_algorithms_conf does nothing. */
    662 OPENSSL_EXPORT void OPENSSL_add_all_algorithms_conf(void);
    663 
    664 /* OpenSSL_add_all_ciphers does nothing. */
    665 OPENSSL_EXPORT void OpenSSL_add_all_ciphers(void);
    666 
    667 /* OpenSSL_add_all_digests does nothing. */
    668 OPENSSL_EXPORT void OpenSSL_add_all_digests(void);
    669 
    670 /* EVP_cleanup does nothing. */
    671 OPENSSL_EXPORT void EVP_cleanup(void);
    672 
    673 OPENSSL_EXPORT void EVP_CIPHER_do_all_sorted(
    674     void (*callback)(const EVP_CIPHER *cipher, const char *name,
    675                      const char *unused, void *arg),
    676     void *arg);
    677 
    678 OPENSSL_EXPORT void EVP_MD_do_all_sorted(void (*callback)(const EVP_MD *cipher,
    679                                                           const char *name,
    680                                                           const char *unused,
    681                                                           void *arg),
    682                                          void *arg);
    683 
    684 /* i2d_PrivateKey marshals a private key from |key| to an ASN.1, DER
    685  * structure. If |outp| is not NULL then the result is written to |*outp| and
    686  * |*outp| is advanced just past the output. It returns the number of bytes in
    687  * the result, whether written or not, or a negative value on error.
    688  *
    689  * RSA keys are serialized as a DER-encoded RSAPublicKey (RFC 3447) structure.
    690  * EC keys are serialized as a DER-encoded ECPrivateKey (RFC 5915) structure.
    691  *
    692  * Use |RSA_marshal_private_key| or |EC_marshal_private_key| instead. */
    693 OPENSSL_EXPORT int i2d_PrivateKey(const EVP_PKEY *key, uint8_t **outp);
    694 
    695 /* i2d_PublicKey marshals a public key from |key| to a type-specific format.
    696  * If |outp| is not NULL then the result is written to |*outp| and
    697  * |*outp| is advanced just past the output. It returns the number of bytes in
    698  * the result, whether written or not, or a negative value on error.
    699  *
    700  * RSA keys are serialized as a DER-encoded RSAPublicKey (RFC 3447) structure.
    701  * EC keys are serialized as an EC point per SEC 1.
    702  *
    703  * Use |RSA_marshal_public_key| or |EC_POINT_point2cbb| instead. */
    704 OPENSSL_EXPORT int i2d_PublicKey(EVP_PKEY *key, uint8_t **outp);
    705 
    706 /* d2i_PrivateKey parses an ASN.1, DER-encoded, private key from |len| bytes at
    707  * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in
    708  * |*out|. Note that, even if |*out| is already non-NULL on entry, it will not
    709  * be written to. Rather, a fresh |EVP_PKEY| is allocated and the previous one
    710  * is freed. On successful exit, |*inp| is advanced past the DER structure. It
    711  * returns the result or NULL on error.
    712  *
    713  * This function tries to detect one of several formats. Instead, use
    714  * |EVP_parse_private_key| for a PrivateKeyInfo, |RSA_parse_private_key| for an
    715  * RSAPrivateKey, and |EC_parse_private_key| for an ECPrivateKey. */
    716 OPENSSL_EXPORT EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **out,
    717                                         const uint8_t **inp, long len);
    718 
    719 /* d2i_AutoPrivateKey acts the same as |d2i_PrivateKey|, but detects the type
    720  * of the private key.
    721  *
    722  * This function tries to detect one of several formats. Instead, use
    723  * |EVP_parse_private_key| for a PrivateKeyInfo, |RSA_parse_private_key| for an
    724  * RSAPrivateKey, and |EC_parse_private_key| for an ECPrivateKey. */
    725 OPENSSL_EXPORT EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **out, const uint8_t **inp,
    726                                             long len);
    727 
    728 /* EVP_PKEY_get0_DH returns NULL. */
    729 OPENSSL_EXPORT DH *EVP_PKEY_get0_DH(EVP_PKEY *pkey);
    730 
    731 
    732 /* Private structures. */
    733 
    734 struct evp_pkey_st {
    735   CRYPTO_refcount_t references;
    736 
    737   /* type contains one of the EVP_PKEY_* values or NID_undef and determines
    738    * which element (if any) of the |pkey| union is valid. */
    739   int type;
    740 
    741   union {
    742     char *ptr;
    743     RSA *rsa;
    744     DSA *dsa;
    745     DH *dh;
    746     EC_KEY *ec;
    747   } pkey;
    748 
    749   /* ameth contains a pointer to a method table that contains many ASN.1
    750    * methods for the key type. */
    751   const EVP_PKEY_ASN1_METHOD *ameth;
    752 } /* EVP_PKEY */;
    753 
    754 
    755 #if defined(__cplusplus)
    756 }  /* extern C */
    757 
    758 extern "C++" {
    759 namespace bssl {
    760 
    761 BORINGSSL_MAKE_DELETER(EVP_PKEY, EVP_PKEY_free)
    762 BORINGSSL_MAKE_DELETER(EVP_PKEY_CTX, EVP_PKEY_CTX_free)
    763 
    764 }  // namespace bssl
    765 
    766 }  /* extern C++ */
    767 
    768 #endif
    769 
    770 #define EVP_R_BUFFER_TOO_SMALL 100
    771 #define EVP_R_COMMAND_NOT_SUPPORTED 101
    772 #define EVP_R_DECODE_ERROR 102
    773 #define EVP_R_DIFFERENT_KEY_TYPES 103
    774 #define EVP_R_DIFFERENT_PARAMETERS 104
    775 #define EVP_R_ENCODE_ERROR 105
    776 #define EVP_R_EXPECTING_AN_EC_KEY_KEY 106
    777 #define EVP_R_EXPECTING_AN_RSA_KEY 107
    778 #define EVP_R_EXPECTING_A_DSA_KEY 108
    779 #define EVP_R_ILLEGAL_OR_UNSUPPORTED_PADDING_MODE 109
    780 #define EVP_R_INVALID_DIGEST_LENGTH 110
    781 #define EVP_R_INVALID_DIGEST_TYPE 111
    782 #define EVP_R_INVALID_KEYBITS 112
    783 #define EVP_R_INVALID_MGF1_MD 113
    784 #define EVP_R_INVALID_OPERATION 114
    785 #define EVP_R_INVALID_PADDING_MODE 115
    786 #define EVP_R_INVALID_PSS_SALTLEN 116
    787 #define EVP_R_KEYS_NOT_SET 117
    788 #define EVP_R_MISSING_PARAMETERS 118
    789 #define EVP_R_NO_DEFAULT_DIGEST 119
    790 #define EVP_R_NO_KEY_SET 120
    791 #define EVP_R_NO_MDC2_SUPPORT 121
    792 #define EVP_R_NO_NID_FOR_CURVE 122
    793 #define EVP_R_NO_OPERATION_SET 123
    794 #define EVP_R_NO_PARAMETERS_SET 124
    795 #define EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE 125
    796 #define EVP_R_OPERATON_NOT_INITIALIZED 126
    797 #define EVP_R_UNKNOWN_PUBLIC_KEY_TYPE 127
    798 #define EVP_R_UNSUPPORTED_ALGORITHM 128
    799 #define EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE 129
    800 
    801 #endif  /* OPENSSL_HEADER_EVP_H */
    802