--- /dev/null
+=pod
+
+=head1 NAME
+
+EVP_PKEY_meth_new, EVP_PKEY_meth_free, EVP_PKEY_meth_copy, EVP_PKEY_meth_find,
+EVP_PKEY_meth_add0, EVP_PKEY_METHOD,
+EVP_PKEY_meth_set_init, EVP_PKEY_meth_set_copy, EVP_PKEY_meth_set_cleanup,
+EVP_PKEY_meth_set_paramgen, EVP_PKEY_meth_set_keygen, EVP_PKEY_meth_set_sign,
+EVP_PKEY_meth_set_verify, EVP_PKEY_meth_set_verify_recover, EVP_PKEY_meth_set_signctx,
+EVP_PKEY_meth_set_verifyctx, EVP_PKEY_meth_set_encrypt, EVP_PKEY_meth_set_decrypt,
+EVP_PKEY_meth_set_derive, EVP_PKEY_meth_set_ctrl,
+EVP_PKEY_meth_get_init, EVP_PKEY_meth_get_copy, EVP_PKEY_meth_get_cleanup,
+EVP_PKEY_meth_get_paramgen, EVP_PKEY_meth_get_keygen, EVP_PKEY_meth_get_sign,
+EVP_PKEY_meth_get_verify, EVP_PKEY_meth_get_verify_recover, EVP_PKEY_meth_get_signctx,
+EVP_PKEY_meth_get_verifyctx, EVP_PKEY_meth_get_encrypt, EVP_PKEY_meth_get_decrypt,
+EVP_PKEY_meth_get_derive, EVP_PKEY_meth_get_ctrl
+- manipulating EVP_PKEY_METHOD structure
+
+=head1 SYNOPSIS
+
+ #include <openssl/evp.h>
+
+ typedef struct evp_pkey_method_st EVP_PKEY_METHOD;
+
+ EVP_PKEY_METHOD *EVP_PKEY_meth_new(int id, int flags);
+ void EVP_PKEY_meth_free(EVP_PKEY_METHOD *pmeth);
+ void EVP_PKEY_meth_copy(EVP_PKEY_METHOD *dst, const EVP_PKEY_METHOD *src);
+ const EVP_PKEY_METHOD *EVP_PKEY_meth_find(int type);
+ int EVP_PKEY_meth_add0(const EVP_PKEY_METHOD *pmeth);
+
+ void EVP_PKEY_meth_set_init(EVP_PKEY_METHOD *pmeth,
+ int (*init) (EVP_PKEY_CTX *ctx));
+ void EVP_PKEY_meth_set_copy(EVP_PKEY_METHOD *pmeth,
+ int (*copy) (EVP_PKEY_CTX *dst,
+ EVP_PKEY_CTX *src));
+ void EVP_PKEY_meth_set_cleanup(EVP_PKEY_METHOD *pmeth,
+ void (*cleanup) (EVP_PKEY_CTX *ctx));
+ void EVP_PKEY_meth_set_paramgen(EVP_PKEY_METHOD *pmeth,
+ int (*paramgen_init) (EVP_PKEY_CTX *ctx),
+ int (*paramgen) (EVP_PKEY_CTX *ctx,
+ EVP_PKEY *pkey));
+ void EVP_PKEY_meth_set_keygen(EVP_PKEY_METHOD *pmeth,
+ int (*keygen_init) (EVP_PKEY_CTX *ctx),
+ int (*keygen) (EVP_PKEY_CTX *ctx,
+ EVP_PKEY *pkey));
+ void EVP_PKEY_meth_set_sign(EVP_PKEY_METHOD *pmeth,
+ int (*sign_init) (EVP_PKEY_CTX *ctx),
+ int (*sign) (EVP_PKEY_CTX *ctx,
+ unsigned char *sig, size_t *siglen,
+ const unsigned char *tbs,
+ size_t tbslen));
+ void EVP_PKEY_meth_set_verify(EVP_PKEY_METHOD *pmeth,
+ int (*verify_init) (EVP_PKEY_CTX *ctx),
+ int (*verify) (EVP_PKEY_CTX *ctx,
+ const unsigned char *sig,
+ size_t siglen,
+ const unsigned char *tbs,
+ size_t tbslen));
+ void EVP_PKEY_meth_set_verify_recover(EVP_PKEY_METHOD *pmeth,
+ int (*verify_recover_init) (EVP_PKEY_CTX
+ *ctx),
+ int (*verify_recover) (EVP_PKEY_CTX
+ *ctx,
+ unsigned char
+ *sig,
+ size_t *siglen,
+ const unsigned
+ char *tbs,
+ size_t tbslen));
+ void EVP_PKEY_meth_set_signctx(EVP_PKEY_METHOD *pmeth,
+ int (*signctx_init) (EVP_PKEY_CTX *ctx,
+ EVP_MD_CTX *mctx),
+ int (*signctx) (EVP_PKEY_CTX *ctx,
+ unsigned char *sig,
+ size_t *siglen,
+ EVP_MD_CTX *mctx));
+ void EVP_PKEY_meth_set_verifyctx(EVP_PKEY_METHOD *pmeth,
+ int (*verifyctx_init) (EVP_PKEY_CTX *ctx,
+ EVP_MD_CTX *mctx),
+ int (*verifyctx) (EVP_PKEY_CTX *ctx,
+ const unsigned char *sig,
+ int siglen,
+ EVP_MD_CTX *mctx));
+ void EVP_PKEY_meth_set_encrypt(EVP_PKEY_METHOD *pmeth,
+ int (*encrypt_init) (EVP_PKEY_CTX *ctx),
+ int (*encryptfn) (EVP_PKEY_CTX *ctx,
+ unsigned char *out,
+ size_t *outlen,
+ const unsigned char *in,
+ size_t inlen));
+ void EVP_PKEY_meth_set_decrypt(EVP_PKEY_METHOD *pmeth,
+ int (*decrypt_init) (EVP_PKEY_CTX *ctx),
+ int (*decrypt) (EVP_PKEY_CTX *ctx,
+ unsigned char *out,
+ size_t *outlen,
+ const unsigned char *in,
+ size_t inlen));
+ void EVP_PKEY_meth_set_derive(EVP_PKEY_METHOD *pmeth,
+ int (*derive_init) (EVP_PKEY_CTX *ctx),
+ int (*derive) (EVP_PKEY_CTX *ctx,
+ unsigned char *key,
+ size_t *keylen));
+ void EVP_PKEY_meth_set_ctrl(EVP_PKEY_METHOD *pmeth,
+ int (*ctrl) (EVP_PKEY_CTX *ctx, int type, int p1,
+ void *p2),
+ int (*ctrl_str) (EVP_PKEY_CTX *ctx,
+ const char *type,
+ const char *value));
+
+ void EVP_PKEY_meth_get_init(EVP_PKEY_METHOD *pmeth,
+ int (**pinit) (EVP_PKEY_CTX *ctx));
+ void EVP_PKEY_meth_get_copy(EVP_PKEY_METHOD *pmeth,
+ int (**pcopy) (EVP_PKEY_CTX *dst,
+ EVP_PKEY_CTX *src));
+ void EVP_PKEY_meth_get_cleanup(EVP_PKEY_METHOD *pmeth,
+ void (**pcleanup) (EVP_PKEY_CTX *ctx));
+ void EVP_PKEY_meth_get_paramgen(EVP_PKEY_METHOD *pmeth,
+ int (**pparamgen_init) (EVP_PKEY_CTX *ctx),
+ int (**pparamgen) (EVP_PKEY_CTX *ctx,
+ EVP_PKEY *pkey));
+ void EVP_PKEY_meth_get_keygen(EVP_PKEY_METHOD *pmeth,
+ int (**pkeygen_init) (EVP_PKEY_CTX *ctx),
+ int (**pkeygen) (EVP_PKEY_CTX *ctx,
+ EVP_PKEY *pkey));
+ void EVP_PKEY_meth_get_sign(EVP_PKEY_METHOD *pmeth,
+ int (**psign_init) (EVP_PKEY_CTX *ctx),
+ int (**psign) (EVP_PKEY_CTX *ctx,
+ unsigned char *sig, size_t *siglen,
+ const unsigned char *tbs,
+ size_t tbslen));
+ void EVP_PKEY_meth_get_verify(EVP_PKEY_METHOD *pmeth,
+ int (**pverify_init) (EVP_PKEY_CTX *ctx),
+ int (**pverify) (EVP_PKEY_CTX *ctx,
+ const unsigned char *sig,
+ size_t siglen,
+ const unsigned char *tbs,
+ size_t tbslen));
+ void EVP_PKEY_meth_get_verify_recover(EVP_PKEY_METHOD *pmeth,
+ int (**pverify_recover_init) (EVP_PKEY_CTX
+ *ctx),
+ int (**pverify_recover) (EVP_PKEY_CTX
+ *ctx,
+ unsigned char
+ *sig,
+ size_t *siglen,
+ const unsigned
+ char *tbs,
+ size_t tbslen));
+ void EVP_PKEY_meth_get_signctx(EVP_PKEY_METHOD *pmeth,
+ int (**psignctx_init) (EVP_PKEY_CTX *ctx,
+ EVP_MD_CTX *mctx),
+ int (**psignctx) (EVP_PKEY_CTX *ctx,
+ unsigned char *sig,
+ size_t *siglen,
+ EVP_MD_CTX *mctx));
+ void EVP_PKEY_meth_get_verifyctx(EVP_PKEY_METHOD *pmeth,
+ int (**pverifyctx_init) (EVP_PKEY_CTX *ctx,
+ EVP_MD_CTX *mctx),
+ int (**pverifyctx) (EVP_PKEY_CTX *ctx,
+ const unsigned char *sig,
+ int siglen,
+ EVP_MD_CTX *mctx));
+ void EVP_PKEY_meth_get_encrypt(EVP_PKEY_METHOD *pmeth,
+ int (**pencrypt_init) (EVP_PKEY_CTX *ctx),
+ int (**pencryptfn) (EVP_PKEY_CTX *ctx,
+ unsigned char *out,
+ size_t *outlen,
+ const unsigned char *in,
+ size_t inlen));
+ void EVP_PKEY_meth_get_decrypt(EVP_PKEY_METHOD *pmeth,
+ int (**pdecrypt_init) (EVP_PKEY_CTX *ctx),
+ int (**pdecrypt) (EVP_PKEY_CTX *ctx,
+ unsigned char *out,
+ size_t *outlen,
+ const unsigned char *in,
+ size_t inlen));
+ void EVP_PKEY_meth_get_derive(EVP_PKEY_METHOD *pmeth,
+ int (**pderive_init) (EVP_PKEY_CTX *ctx),
+ int (**pderive) (EVP_PKEY_CTX *ctx,
+ unsigned char *key,
+ size_t *keylen));
+ void EVP_PKEY_meth_get_ctrl(EVP_PKEY_METHOD *pmeth,
+ int (**pctrl) (EVP_PKEY_CTX *ctx, int type, int p1,
+ void *p2),
+ int (**pctrl_str) (EVP_PKEY_CTX *ctx,
+ const char *type,
+ const char *value));
+
+=head1 DESCRIPTION
+
+B<EVP_PKEY_METHOD> is a structure which holds a set of methods for a
+specific public key cryptographic algorithm. Those methods are usually
+used to perform different jobs, such as generating a key, signing or
+verifying, encrypting or decrypting, etc.
+
+There are two places where the B<EVP_PKEY_METHOD> objects are stored: one
+is a built-in static array representing the standard methods for different
+algorithms, and the other one is a stack of user-defined application-specific
+methods, which can be manipulated by using L<EVP_PKEY_meth_add0(3)>.
+
+The B<EVP_PKEY_METHOD> objects are usually referenced by B<EVP_PKEY_CTX>
+objects.
+
+=head2 Methods
+
+The methods are the underlying implementations of a particular public key
+algorithm present by the B<EVP_PKEY_CTX> object.
+
+ int (*init) (EVP_PKEY_CTX *ctx);
+ int (*copy) (EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src);
+ void (*cleanup) (EVP_PKEY_CTX *ctx);
+
+The init() method is called to initialize algorithm-specific data when a new
+B<EVP_PKEY_CTX> is created. As opposed to init(), the cleanup() method is called
+when an B<EVP_PKEY_CTX> is freed. The copy() method is called when an B<EVP_PKEY_CTX>
+is being duplicated. Refer to L<EVP_PKEY_CTX_new(3)>, L<EVP_PKEY_CTX_new_id(3)>,
+L<EVP_PKEY_CTX_free(3)> and L<EVP_PKEY_CTX_dup(3)>.
+
+ int (*paramgen_init) (EVP_PKEY_CTX *ctx);
+ int (*paramgen) (EVP_PKEY_CTX *ctx, EVP_PKEY *pkey);
+
+The paramgen_init() and paramgen() methods deal with key parameter generation.
+They are called by L<EVP_PKEY_paramgen_init(3)> and L<EVP_PKEY_paramgen(3)> to
+handle the parameter generation process.
+
+ int (*keygen_init) (EVP_PKEY_CTX *ctx);
+ int (*keygen) (EVP_PKEY_CTX *ctx, EVP_PKEY *pkey);
+
+The keygen_init() and keygen() methods are used to generate the actual key for
+the specified algorithm. They are called by L<EVP_PKEY_keygen_init(3)> and
+L<EVP_PKEY_keygen(3)>.
+
+ int (*sign_init) (EVP_PKEY_CTX *ctx);
+ int (*sign) (EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
+ const unsigned char *tbs, size_t tbslen);
+
+The sign_init() and sign() methods are used to generate the signature of a
+piece of data using a private key. They are called by L<EVP_PKEY_sign_init(3)>
+and L<EVP_PKEY_sign(3)>.
+
+ int (*verify_init) (EVP_PKEY_CTX *ctx);
+ int (*verify) (EVP_PKEY_CTX *ctx,
+ const unsigned char *sig, size_t siglen,
+ const unsigned char *tbs, size_t tbslen);
+
+The verify_init() and verify() methods are used to verify whether a signature is
+valid. They are called by L<EVP_PKEY_verify_init(3)> and L<EVP_PKEY_verify(3)>.
+
+ int (*verify_recover_init) (EVP_PKEY_CTX *ctx);
+ int (*verify_recover) (EVP_PKEY_CTX *ctx,
+ unsigned char *rout, size_t *routlen,
+ const unsigned char *sig, size_t siglen);
+
+The verify_recover_init() and verify_recover() methods are used to verify a
+signature and then recover the digest from the signature (for instance, a
+signature that was generated by RSA signing algorithm). They are called by
+L<EVP_PKEY_verify_recover_init(3)> and L<EVP_PKEY_verify_recover(3)>.
+
+ int (*signctx_init) (EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx);
+ int (*signctx) (EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
+ EVP_MD_CTX *mctx);
+
+The signctx_init() and signctx() methods are used to sign a digest present by
+a B<EVP_MD_CTX> object. They are called by the EVP_DigestSign functions. See
+L<EVP_DigestSignInit(3)> for detail.
+
+ int (*verifyctx_init) (EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx);
+ int (*verifyctx) (EVP_PKEY_CTX *ctx, const unsigned char *sig, int siglen,
+ EVP_MD_CTX *mctx);
+
+The verifyctx_init() and verifyctx() methods are used to verify a signature
+against the data in a B<EVP_MD_CTX> object. They are called by the various
+EVP_DigestVerify functions. See L<EVP_DigestVerifyInit(3)> for detail.
+
+ int (*encrypt_init) (EVP_PKEY_CTX *ctx);
+ int (*encrypt) (EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen,
+ const unsigned char *in, size_t inlen);
+
+The encrypt_init() and encrypt() methods are used to encrypt a piece of data.
+They are called by L<EVP_PKEY_encrypt_init(3)> and L<EVP_PKEY_encrypt(3)>.
+
+ int (*decrypt_init) (EVP_PKEY_CTX *ctx);
+ int (*decrypt) (EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen,
+ const unsigned char *in, size_t inlen);
+
+The decrypt_init() and decrypt() methods are used to decrypt a piece of data.
+They are called by L<EVP_PKEY_decrypt_init(3)> and L<EVP_PKEY_decrypt(3)>.
+
+ int (*derive_init) (EVP_PKEY_CTX *ctx);
+ int (*derive) (EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen);
+
+The derive_init() and derive() methods are used to derive the shared secret
+from a public key algorithm (for instance, the DH algorithm). They are called by
+L<EVP_PKEY_derive_init(3)> and L<EVP_PKEY_derive(3)>.
+
+ int (*ctrl) (EVP_PKEY_CTX *ctx, int type, int p1, void *p2);
+ int (*ctrl_str) (EVP_PKEY_CTX *ctx, const char *type, const char *value);
+
+The ctrl() and ctrl_str() methods are used to adjust algorithm-specific
+settings. See L<EVP_PKEY_CTX_ctrl(3)> and related functions for detail.
+
+ int (*digestsign) (EVP_MD_CTX *ctx, unsigned char *sig, size_t *siglen,
+ const unsigned char *tbs, size_t tbslen);
+ int (*digestverify) (EVP_MD_CTX *ctx, const unsigned char *sig,
+ size_t siglen, const unsigned char *tbs,
+ size_t tbslen);
+
+The digestsign() and digestverify() methods are used to generate or verify
+a signature in a one-shot mode. They could be called by L<EVP_DigetSign(3)>
+and L<EVP_DigestVerify(3)>.
+
+=head2 Functions
+
+EVP_PKEY_meth_new() creates and returns a new B<EVP_PKEY_METHOD> object,
+and associates the given B<id> and B<flags>. The following flags are
+supported:
+
+ EVP_PKEY_FLAG_AUTOARGLEN
+ EVP_PKEY_FLAG_SIGCTX_CUSTOM
+
+If an B<EVP_PKEY_METHOD> is set with the B<EVP_PKEY_FLAG_AUTOARGLEN> flag, the
+maximum size of the output buffer will be automatically calculated or checked
+in corresponding EVP methods by the EVP framework. Thus the implementations of
+these methods don't need to care about handling the case of returning output
+buffer size by themselves. For details on the output buffer size, refer to
+L<EVP_PKEY_sign(3)>.
+
+The B<EVP_PKEY_FLAG_SIGCTX_CUSTOM> is used to indicate the signctx() method
+of an B<EVP_PKEY_METHOD> is always called by the EVP framework while doing a
+digest signing operation by calling L<EVP_DigestSignFinal(3)>.
+
+EVP_PKEY_meth_free() frees an existing B<EVP_PKEY_METHOD> pointed by
+B<pmeth>.
+
+EVP_PKEY_meth_copy() copies an B<EVP_PKEY_METHOD> object from B<src>
+to B<dst>.
+
+EVP_PKEY_meth_find() finds an B<EVP_PKEY_METHOD> object with the B<id>.
+This function first searches through the user-defined method objects and
+then the built-in objects.
+
+EVP_PKEY_meth_add0() adds B<pmeth> to the user defined stack of methods.
+
+The EVP_PKEY_meth_set functions set the corresponding fields of
+B<EVP_PKEY_METHOD> structure with the arguments passed.
+
+The EVP_PKEY_meth_get functions get the corresponding fields of
+B<EVP_PKEY_METHOD> structure to the arguments provided.
+
+=head1 RETURN VALUES
+
+EVP_PKEY_meth_new() returns a pointer to a new B<EVP_PKEY_METHOD>
+object or returns NULL on error.
+
+EVP_PKEY_meth_free() and EVP_PKEY_meth_copy() do not return values.
+
+EVP_PKEY_meth_find() returns a pointer to the found B<EVP_PKEY_METHOD>
+object or returns NULL if not found.
+
+EVP_PKEY_meth_add0() returns 1 if method is added successfully or 0
+if an error occurred.
+
+All EVP_PKEY_meth_set and EVP_PKEY_meth_get functions have no return
+values. For the 'get' functions, function pointers are returned by
+arguments.
+
+=head1 COPYRIGHT
+
+Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (the "License"). You may not use
+this file except in compliance with the License. You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut
projects / oweals / openssl.git / commitdiff