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Diffstat (limited to 'doc/crypto/EVP_PKEY_meth_new.pod')
| -rw-r--r-- | doc/crypto/EVP_PKEY_meth_new.pod | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/doc/crypto/EVP_PKEY_meth_new.pod b/doc/crypto/EVP_PKEY_meth_new.pod new file mode 100644 index 000000000000..041492a8f0fb --- /dev/null +++ b/doc/crypto/EVP_PKEY_meth_new.pod @@ -0,0 +1,376 @@ +=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 |