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<ul id="index">
 <li><a href="#NAME">NAME</a></li>
 <li><a href="#SYNOPSIS">SYNOPSIS</a></li>
 <li><a href="#DESCRIPTION">DESCRIPTION</a>
 <ul>
 <li><a href="#Methods">Methods</a></li>
 <li><a href="#Functions">Functions</a></li>
 </ul>
 </li>
 <li><a href="#RETURN-VALUES">RETURN VALUES</a></li>
 <li><a href="#COPYRIGHT">COPYRIGHT</a></li>
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EVP_PKEY_ASN1_METHOD, EVP_PKEY_asn1_new, EVP_PKEY_asn1_copy, EVP_PKEY_asn1_free, EVP_PKEY_asn1_add0, EVP_PKEY_asn1_add_alias, EVP_PKEY_asn1_set_public, EVP_PKEY_asn1_set_private, EVP_PKEY_asn1_set_param, EVP_PKEY_asn1_set_free, EVP_PKEY_asn1_set_ctrl, EVP_PKEY_asn1_set_item, EVP_PKEY_asn1_set_siginf, EVP_PKEY_asn1_set_check, EVP_PKEY_asn1_set_public_check, EVP_PKEY_asn1_set_param_check, EVP_PKEY_asn1_set_security_bits, EVP_PKEY_asn1_set_set_priv_key, EVP_PKEY_asn1_set_set_pub_key, EVP_PKEY_asn1_set_get_priv_key, EVP_PKEY_asn1_set_get_pub_key, EVP_PKEY_get0_asn1 - manipulating and registering EVP_PKEY_ASN1_METHOD structure

<h1 id="SYNOPSIS">SYNOPSIS</h1>

<pre><code> #include &lt;openssl/evp.h&gt;

typedef struct evp_pkey_asn1_method_st EVP_PKEY_ASN1_METHOD;

EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_new(int id, int flags,
                                         const char *pem_str,
                                         const char *info);
 void EVP_PKEY_asn1_copy(EVP_PKEY_ASN1_METHOD *dst,
                         const EVP_PKEY_ASN1_METHOD *src);
 void EVP_PKEY_asn1_free(EVP_PKEY_ASN1_METHOD *ameth);
 int EVP_PKEY_asn1_add0(const EVP_PKEY_ASN1_METHOD *ameth);
 int EVP_PKEY_asn1_add_alias(int to, int from);

void EVP_PKEY_asn1_set_public(EVP_PKEY_ASN1_METHOD *ameth,
                               int (*pub_decode) (EVP_PKEY *pk,
                                                  X509_PUBKEY *pub),
                               int (*pub_encode) (X509_PUBKEY *pub,
                                                  const EVP_PKEY *pk),
                               int (*pub_cmp) (const EVP_PKEY *a,
                                               const EVP_PKEY *b),
                               int (*pub_print) (BIO *out,
                                                 const EVP_PKEY *pkey,
                                                 int indent, ASN1_PCTX *pctx),
                               int (*pkey_size) (const EVP_PKEY *pk),
                               int (*pkey_bits) (const EVP_PKEY *pk));
 void EVP_PKEY_asn1_set_private(EVP_PKEY_ASN1_METHOD *ameth,
                                int (*priv_decode) (EVP_PKEY *pk,
                                                    const PKCS8_PRIV_KEY_INFO
                                                    *p8inf),
                                int (*priv_encode) (PKCS8_PRIV_KEY_INFO *p8,
                                                    const EVP_PKEY *pk),
                                int (*priv_print) (BIO *out,
                                                   const EVP_PKEY *pkey,
                                                   int indent,
                                                   ASN1_PCTX *pctx));
 void EVP_PKEY_asn1_set_param(EVP_PKEY_ASN1_METHOD *ameth,
                              int (*param_decode) (EVP_PKEY *pkey,
                                                   const unsigned char **pder,
                                                   int derlen),
                              int (*param_encode) (const EVP_PKEY *pkey,
                                                   unsigned char **pder),
                              int (*param_missing) (const EVP_PKEY *pk),
                              int (*param_copy) (EVP_PKEY *to,
                                                 const EVP_PKEY *from),
                              int (*param_cmp) (const EVP_PKEY *a,
                                                const EVP_PKEY *b),
                              int (*param_print) (BIO *out,
                                                  const EVP_PKEY *pkey,
                                                  int indent,
                                                  ASN1_PCTX *pctx));

void EVP_PKEY_asn1_set_free(EVP_PKEY_ASN1_METHOD *ameth,
                             void (*pkey_free) (EVP_PKEY *pkey));
 void EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
                             int (*pkey_ctrl) (EVP_PKEY *pkey, int op,
                                               long arg1, void *arg2));
 void EVP_PKEY_asn1_set_item(EVP_PKEY_ASN1_METHOD *ameth,
                             int (*item_verify) (EVP_MD_CTX *ctx,
                                                 const ASN1_ITEM *it,
                                                 void *asn,
                                                 X509_ALGOR *a,
                                                 ASN1_BIT_STRING *sig,
                                                 EVP_PKEY *pkey),
                             int (*item_sign) (EVP_MD_CTX *ctx,
                                               const ASN1_ITEM *it,
                                               void *asn,
                                               X509_ALGOR *alg1,
                                               X509_ALGOR *alg2,
                                               ASN1_BIT_STRING *sig));

void EVP_PKEY_asn1_set_siginf(EVP_PKEY_ASN1_METHOD *ameth,
                               int (*siginf_set) (X509_SIG_INFO *siginf,
                                                  const X509_ALGOR *alg,
                                                  const ASN1_STRING *sig));

void EVP_PKEY_asn1_set_check(EVP_PKEY_ASN1_METHOD *ameth,
                              int (*pkey_check) (const EVP_PKEY *pk));

void EVP_PKEY_asn1_set_public_check(EVP_PKEY_ASN1_METHOD *ameth,
                                     int (*pkey_pub_check) (const EVP_PKEY *pk));

void EVP_PKEY_asn1_set_param_check(EVP_PKEY_ASN1_METHOD *ameth,
                                    int (*pkey_param_check) (const EVP_PKEY *pk));

void EVP_PKEY_asn1_set_security_bits(EVP_PKEY_ASN1_METHOD *ameth,
                                      int (*pkey_security_bits) (const EVP_PKEY
                                                                 *pk));

void EVP_PKEY_asn1_set_set_priv_key(EVP_PKEY_ASN1_METHOD *ameth,
                                     int (*set_priv_key) (EVP_PKEY *pk,
                                                          const unsigned char
                                                             *priv,
                                                          size_t len));

void EVP_PKEY_asn1_set_set_pub_key(EVP_PKEY_ASN1_METHOD *ameth,
                                    int (*set_pub_key) (EVP_PKEY *pk,
                                                        const unsigned char *pub,
                                                        size_t len));

void EVP_PKEY_asn1_set_get_priv_key(EVP_PKEY_ASN1_METHOD *ameth,
                                     int (*get_priv_key) (const EVP_PKEY *pk,
                                                          unsigned char *priv,
                                                          size_t *len));

void EVP_PKEY_asn1_set_get_pub_key(EVP_PKEY_ASN1_METHOD *ameth,
                                    int (*get_pub_key) (const EVP_PKEY *pk,
                                                        unsigned char *pub,
                                                        size_t *len));

const EVP_PKEY_ASN1_METHOD *EVP_PKEY_get0_asn1(const EVP_PKEY *pkey);</code></pre>

<h1 id="DESCRIPTION">DESCRIPTION</h1>

EVP_PKEY_ASN1_METHOD is a structure which holds a set of ASN.1 conversion, printing and information methods for a specific public key algorithm.

There are two places where the EVP_PKEY_ASN1_METHOD objects are stored: one is a built-in 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 <a href="../man3/EVP_PKEY_asn1_add0.html">EVP_PKEY_asn1_add0(3)</a>.

<h2 id="Methods">Methods</h2>

The methods are the underlying implementations of a particular public key algorithm present by the EVP_PKEY object.

<pre><code> int (*pub_decode) (EVP_PKEY *pk, X509_PUBKEY *pub);
 int (*pub_encode) (X509_PUBKEY *pub, const EVP_PKEY *pk);
 int (*pub_cmp) (const EVP_PKEY *a, const EVP_PKEY *b);
 int (*pub_print) (BIO *out, const EVP_PKEY *pkey, int indent,
 ASN1_PCTX *pctx);</code></pre>

The pub_decode() and pub_encode() methods are called to decode / encode X509_PUBKEY ASN.1 parameters to / from pk. They MUST return 0 on error, 1 on success. They&#39;re called by <a href="../man3/X509_PUBKEY_get0.html">X509_PUBKEY_get0(3)</a> and <a href="../man3/X509_PUBKEY_set.html">X509_PUBKEY_set(3)</a>.

The pub_cmp() method is called when two public keys are to be compared. It MUST return 1 when the keys are equal, 0 otherwise. It&#39;s called by <a href="../man3/EVP_PKEY_cmp.html">EVP_PKEY_cmp(3)</a>.

The pub_print() method is called to print a public key in humanly readable text to out, indented indent spaces. It MUST return 0 on error, 1 on success. It&#39;s called by <a href="../man3/EVP_PKEY_print_public.html">EVP_PKEY_print_public(3)</a>.

<pre><code> int (*priv_decode) (EVP_PKEY *pk, const PKCS8_PRIV_KEY_INFO *p8inf);
 int (*priv_encode) (PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pk);
 int (*priv_print) (BIO *out, const EVP_PKEY *pkey, int indent,
 ASN1_PCTX *pctx);</code></pre>

The priv_decode() and priv_encode() methods are called to decode / encode PKCS8_PRIV_KEY_INFO form private key to / from pk. They MUST return 0 on error, 1 on success. They&#39;re called by <a href="../man3/EVP_PKCS82PKEY.html">EVP_PKCS82PKEY(3)</a> and <a href="../man3/EVP_PKEY2PKCS8.html">EVP_PKEY2PKCS8(3)</a>.

The priv_print() method is called to print a private key in humanly readable text to out, indented indent spaces. It MUST return 0 on error, 1 on success. It&#39;s called by <a href="../man3/EVP_PKEY_print_private.html">EVP_PKEY_print_private(3)</a>.

<pre><code> int (*pkey_size) (const EVP_PKEY *pk);
 int (*pkey_bits) (const EVP_PKEY *pk);
 int (*pkey_security_bits) (const EVP_PKEY *pk);</code></pre>

The pkey_size() method returns the key size in bytes. It&#39;s called by <a href="../man3/EVP_PKEY_size.html">EVP_PKEY_size(3)</a>.

The pkey_bits() method returns the key size in bits. It&#39;s called by <a href="../man3/EVP_PKEY_bits.html">EVP_PKEY_bits(3)</a>.

<pre><code> int (*param_decode) (EVP_PKEY *pkey,
 const unsigned char **pder, int derlen);
 int (*param_encode) (const EVP_PKEY *pkey, unsigned char **pder);
 int (*param_missing) (const EVP_PKEY *pk);
 int (*param_copy) (EVP_PKEY *to, const EVP_PKEY *from);
 int (*param_cmp) (const EVP_PKEY *a, const EVP_PKEY *b);
 int (*param_print) (BIO *out, const EVP_PKEY *pkey, int indent,
 ASN1_PCTX *pctx);</code></pre>

The param_decode() and param_encode() methods are called to decode / encode DER formatted parameters to / from pk. They MUST return 0 on error, 1 on success. They&#39;re called by <a href="../man3/PEM_read_bio_Parameters.html">PEM_read_bio_Parameters(3)</a> and the file: <a href="../man3/OSSL_STORE_LOADER.html">OSSL_STORE_LOADER(3)</a>.

The param_missing() method returns 0 if a key parameter is missing, otherwise 1. It&#39;s called by <a href="../man3/EVP_PKEY_missing_parameters.html">EVP_PKEY_missing_parameters(3)</a>.

The param_copy() method copies key parameters from from to to. It MUST return 0 on error, 1 on success. It&#39;s called by <a href="../man3/EVP_PKEY_copy_parameters.html">EVP_PKEY_copy_parameters(3)</a>.

The param_cmp() method compares the parameters of keys a and b. It MUST return 1 when the keys are equal, 0 when not equal, or a negative number on error. It&#39;s called by <a href="../man3/EVP_PKEY_cmp_parameters.html">EVP_PKEY_cmp_parameters(3)</a>.

The param_print() method prints the private key parameters in humanly readable text to out, indented indent spaces. It MUST return 0 on error, 1 on success. It&#39;s called by <a href="../man3/EVP_PKEY_print_params.html">EVP_PKEY_print_params(3)</a>.

<pre><code> int (*sig_print) (BIO *out,
 const X509_ALGOR *sigalg, const ASN1_STRING *sig,
 int indent, ASN1_PCTX *pctx);</code></pre>

The sig_print() method prints a signature in humanly readable text to out, indented indent spaces. sigalg contains the exact signature algorithm. If the signature in sig doesn&#39;t correspond to what this method expects, X509_signature_dump() must be used as a last resort. It MUST return 0 on error, 1 on success. It&#39;s called by <a href="../man3/X509_signature_print.html">X509_signature_print(3)</a>.

The pkey_free() method helps freeing the internals of pkey. It&#39;s called by <a href="../man3/EVP_PKEY_free.html">EVP_PKEY_free(3)</a>, <a href="../man3/EVP_PKEY_set_type.html">EVP_PKEY_set_type(3)</a>, <a href="../man3/EVP_PKEY_set_type_str.html">EVP_PKEY_set_type_str(3)</a>, and <a href="../man3/EVP_PKEY_assign.html">EVP_PKEY_assign(3)</a>.

The pkey_ctrl() method adds extra algorithm specific control. It&#39;s called by <a href="../man3/EVP_PKEY_get_default_digest_nid.html">EVP_PKEY_get_default_digest_nid(3)</a>, <a href="../man3/EVP_PKEY_set1_tls_encodedpoint.html">EVP_PKEY_set1_tls_encodedpoint(3)</a>, <a href="../man3/EVP_PKEY_get1_tls_encodedpoint.html">EVP_PKEY_get1_tls_encodedpoint(3)</a>, <a href="../man3/PKCS7_SIGNER_INFO_set.html">PKCS7_SIGNER_INFO_set(3)</a>, <a href="../man3/PKCS7_RECIP_INFO_set.html">PKCS7_RECIP_INFO_set(3)</a>, ...

<pre><code> int (*old_priv_decode) (EVP_PKEY *pkey,
 const unsigned char **pder, int derlen);
 int (*old_priv_encode) (const EVP_PKEY *pkey, unsigned char **pder);</code></pre>

The old_priv_decode() and old_priv_encode() methods decode / encode they private key pkey from / to a DER formatted array. These are exclusively used to help decoding / encoding older (pre PKCS#8) PEM formatted encrypted private keys. old_priv_decode() MUST return 0 on error, 1 on success. old_priv_encode() MUST the return same kind of values as i2d_PrivateKey(). They&#39;re called by <a href="../man3/d2i_PrivateKey.html">d2i_PrivateKey(3)</a> and <a href="../man3/i2d_PrivateKey.html">i2d_PrivateKey(3)</a>.

<pre><code> int (*item_verify) (EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
 X509_ALGOR *a, ASN1_BIT_STRING *sig, EVP_PKEY *pkey);
 int (*item_sign) (EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
 X509_ALGOR *alg1, X509_ALGOR *alg2,
 ASN1_BIT_STRING *sig);</code></pre>

The item_sign() and item_verify() methods make it possible to have algorithm specific signatures and verification of them.

item_sign() MUST return one of:

<dl>

error

</dd>
<dt id="pod1">1</dt>
<dd>

item_sign() did everything, OpenSSL internals just needs to pass the signature length back.

</dd>
<dt id="pod2">2</dt>
<dd>

item_sign() did nothing, OpenSSL internal standard routines are expected to continue with the default signature production.

</dd>
<dt id="pod3">3</dt>
<dd>

item_sign() set the algorithm identifier algor1 and algor2, OpenSSL internals should just sign using those algorithms.

</dd>
</dl>

item_verify() MUST return one of:

<dl>

error

</dd>
<dt id="pod11">1</dt>
<dd>

item_sign() did everything, OpenSSL internals just needs to pass the signature length back.

</dd>
<dt id="pod21">2</dt>
<dd>

item_sign() did nothing, OpenSSL internal standard routines are expected to continue with the default signature production.

</dd>
</dl>

item_verify() and item_sign() are called by <a href="../man3/ASN1_item_verify.html">ASN1_item_verify(3)</a> and <a href="../man3/ASN1_item_sign.html">ASN1_item_sign(3)</a>, and by extension, <a href="../man3/X509_verify.html">X509_verify(3)</a>, <a href="../man3/X509_REQ_verify.html">X509_REQ_verify(3)</a>, <a href="../man3/X509_sign.html">X509_sign(3)</a>, <a href="../man3/X509_REQ_sign.html">X509_REQ_sign(3)</a>, ...

<pre><code> int (*siginf_set) (X509_SIG_INFO *siginf, const X509_ALGOR *alg,
 const ASN1_STRING *sig);</code></pre>

The siginf_set() method is used to set custom X509_SIG_INFO parameters. It MUST return 0 on error, or 1 on success. It&#39;s called as part of <a href="../man3/X509_check_purpose.html">X509_check_purpose(3)</a>, <a href="../man3/X509_check_ca.html">X509_check_ca(3)</a> and <a href="../man3/X509_check_issued.html">X509_check_issued(3)</a>.

<pre><code> int (*pkey_check) (const EVP_PKEY *pk);
 int (*pkey_public_check) (const EVP_PKEY *pk);
 int (*pkey_param_check) (const EVP_PKEY *pk);</code></pre>

The pkey_check(), pkey_public_check() and pkey_param_check() methods are used to check the validity of pk for key-pair, public component and parameters, respectively. They MUST return 0 for an invalid key, or 1 for a valid key. They are called by <a href="../man3/EVP_PKEY_check.html">EVP_PKEY_check(3)</a>, <a href="../man3/EVP_PKEY_public_check.html">EVP_PKEY_public_check(3)</a> and <a href="../man3/EVP_PKEY_param_check.html">EVP_PKEY_param_check(3)</a> respectively.

<pre><code> int (*set_priv_key) (EVP_PKEY *pk, const unsigned char *priv, size_t len);
 int (*set_pub_key) (EVP_PKEY *pk, const unsigned char *pub, size_t len);</code></pre>

The set_priv_key() and set_pub_key() methods are used to set the raw private and public key data for an EVP_PKEY. They MUST return 0 on error, or 1 on success. They are called by <a href="../man3/EVP_PKEY_new_raw_private_key.html">EVP_PKEY_new_raw_private_key(3)</a>, and <a href="../man3/EVP_PKEY_new_raw_public_key.html">EVP_PKEY_new_raw_public_key(3)</a> respectively.

<h2 id="Functions">Functions</h2>

EVP_PKEY_asn1_new() creates and returns a new EVP_PKEY_ASN1_METHOD object, and associates the given id, flags, pem_str and info. id is a NID, pem_str is the PEM type string, info is a descriptive string. The following flags are supported:

<pre><code> ASN1_PKEY_SIGPARAM_NULL</code></pre>

If ASN1_PKEY_SIGPARAM_NULL is set, then the signature algorithm parameters are given the type V_ASN1_NULL by default, otherwise they will be given the type V_ASN1_UNDEF (i.e. the parameter is omitted). See <a href="../man3/X509_ALGOR_set0.html">X509_ALGOR_set0(3)</a> for more information.

EVP_PKEY_asn1_copy() copies an EVP_PKEY_ASN1_METHOD object from src to dst. This function is not thread safe, it&#39;s recommended to only use this when initializing the application.

EVP_PKEY_asn1_free() frees an existing EVP_PKEY_ASN1_METHOD pointed by ameth.

EVP_PKEY_asn1_add0() adds ameth to the user defined stack of methods unless another EVP_PKEY_ASN1_METHOD with the same NID is already there. This function is not thread safe, it&#39;s recommended to only use this when initializing the application.

EVP_PKEY_asn1_add_alias() creates an alias with the NID to for the EVP_PKEY_ASN1_METHOD with NID from unless another EVP_PKEY_ASN1_METHOD with the same NID is already added. This function is not thread safe, it&#39;s recommended to only use this when initializing the application.

EVP_PKEY_asn1_set_public(), EVP_PKEY_asn1_set_private(), EVP_PKEY_asn1_set_param(), EVP_PKEY_asn1_set_free(), EVP_PKEY_asn1_set_ctrl(), EVP_PKEY_asn1_set_item(), EVP_PKEY_asn1_set_siginf(), EVP_PKEY_asn1_set_check(), EVP_PKEY_asn1_set_public_check(), EVP_PKEY_asn1_set_param_check(), EVP_PKEY_asn1_set_security_bits(), EVP_PKEY_asn1_set_set_priv_key(), EVP_PKEY_asn1_set_set_pub_key(), EVP_PKEY_asn1_set_get_priv_key() and EVP_PKEY_asn1_set_get_pub_key() set the diverse methods of the given EVP_PKEY_ASN1_METHOD object.

EVP_PKEY_get0_asn1() finds the EVP_PKEY_ASN1_METHOD associated with the key pkey.

<h1 id="RETURN-VALUES">RETURN VALUES</h1>

EVP_PKEY_asn1_new() returns NULL on error, or a pointer to an EVP_PKEY_ASN1_METHOD object otherwise.

EVP_PKEY_asn1_add0() and EVP_PKEY_asn1_add_alias() return 0 on error, or 1 on success.

EVP_PKEY_get0_asn1() returns NULL on error, or a pointer to a constant EVP_PKEY_ASN1_METHOD object otherwise.

<h1 id="COPYRIGHT">COPYRIGHT</h1>

Licensed under the OpenSSL license (the &quot;License&quot;). 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 <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.

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MR SKB