| EVP_PKEY_fromdata(3) | OpenSSL | EVP_PKEY_fromdata(3) |
#include <openssl/evp.h>
int EVP_PKEY_fromdata_init(EVP_PKEY_CTX *ctx);
int EVP_PKEY_fromdata(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey, int selection,
OSSL_PARAM params[]);
const OSSL_PARAM *EVP_PKEY_fromdata_settable(EVP_PKEY_CTX *ctx, int selection);
These functions use an EVP_PKEY_CTX context, which should primarily be created with EVP_PKEY_CTX_new_from_name(3) or EVP_PKEY_CTX_new_id(3).
The exact key data that the user can pass depends on the key type. These are passed as an OSSL_PARAM(3) array.
EVP_PKEY_fromdata_init() initializes a public key algorithm context for creating a key or key parameters from user data.
EVP_PKEY_fromdata() creates the structure to store a key or key parameters, given data from params, selection and a context that's been initialized with EVP_PKEY_fromdata_init(). The result is written to *ppkey. selection is described in "Selections". The parameters that can be used for various types of key are as described by the diverse "Common parameters" sections of the EVP_PKEY-RSA(7), EVP_PKEY-DSA(7), EVP_PKEY-DH(7), EVP_PKEY-EC(7), EVP_PKEY-ED448(7), EVP_PKEY-X25519(7), EVP_PKEY-X448(7), and EVP_PKEY-ED25519(7) pages.
EVP_PKEY_fromdata_settable() gets a constant OSSL_PARAM(3) array that describes the settable parameters that can be used with EVP_PKEY_fromdata(). selection is described in "Selections".
Parameters in the params array that are not among the settable parameters for the given selection are ignored.
#include <openssl/evp.h>
/*
* These are extremely small to make this example simple. A real
* and secure application will not use such small numbers. A real
* and secure application is expected to use BIGNUMs, and to build
* this array dynamically.
*/
unsigned long rsa_n = 0xbc747fc5;
unsigned long rsa_e = 0x10001;
unsigned long rsa_d = 0x7b133399;
OSSL_PARAM params[] = {
OSSL_PARAM_ulong("n", &rsa_n),
OSSL_PARAM_ulong("e", &rsa_e),
OSSL_PARAM_ulong("d", &rsa_d),
OSSL_PARAM_END
};
int main()
{
EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
EVP_PKEY *pkey = NULL;
if (ctx == NULL
|| EVP_PKEY_fromdata_init(ctx) <= 0
|| EVP_PKEY_fromdata(ctx, &pkey, EVP_PKEY_KEYPAIR, params) <= 0)
exit(1);
/* Do what you want with |pkey| */
}
#include <openssl/evp.h>
#include <openssl/param_build.h>
#include <openssl/ec.h>
/*
* Fixed data to represent the private and public key.
*/
const unsigned char priv_data[] = {
0xb9, 0x2f, 0x3c, 0xe6, 0x2f, 0xfb, 0x45, 0x68,
0x39, 0x96, 0xf0, 0x2a, 0xaf, 0x6c, 0xda, 0xf2,
0x89, 0x8a, 0x27, 0xbf, 0x39, 0x9b, 0x7e, 0x54,
0x21, 0xc2, 0xa1, 0xe5, 0x36, 0x12, 0x48, 0x5d
};
/* UNCOMPRESSED FORMAT */
const unsigned char pub_data[] = {
POINT_CONVERSION_UNCOMPRESSED,
0xcf, 0x20, 0xfb, 0x9a, 0x1d, 0x11, 0x6c, 0x5e,
0x9f, 0xec, 0x38, 0x87, 0x6c, 0x1d, 0x2f, 0x58,
0x47, 0xab, 0xa3, 0x9b, 0x79, 0x23, 0xe6, 0xeb,
0x94, 0x6f, 0x97, 0xdb, 0xa3, 0x7d, 0xbd, 0xe5,
0x26, 0xca, 0x07, 0x17, 0x8d, 0x26, 0x75, 0xff,
0xcb, 0x8e, 0xb6, 0x84, 0xd0, 0x24, 0x02, 0x25,
0x8f, 0xb9, 0x33, 0x6e, 0xcf, 0x12, 0x16, 0x2f,
0x5c, 0xcd, 0x86, 0x71, 0xa8, 0xbf, 0x1a, 0x47
};
int main()
{
EVP_PKEY_CTX *ctx;
EVP_PKEY *pkey = NULL;
BIGNUM *priv;
OSSL_PARAM_BLD *param_bld;
OSSL_PARAM *params = NULL;
int exitcode = 0;
priv = BN_bin2bn(priv_data, sizeof(priv_data), NULL);
param_bld = OSSL_PARAM_BLD_new();
if (priv != NULL && param_bld != NULL
&& OSSL_PARAM_BLD_push_utf8_string(param_bld, "group",
"prime256v1", 0)
&& OSSL_PARAM_BLD_push_BN(param_bld, "priv", priv)
&& OSSL_PARAM_BLD_push_octet_string(param_bld, "pub",
pub_data, sizeof(pub_data)))
params = OSSL_PARAM_BLD_to_param(param_bld);
ctx = EVP_PKEY_CTX_new_from_name(NULL, "EC", NULL);
if (ctx == NULL
|| params == NULL
|| EVP_PKEY_fromdata_init(ctx) <= 0
|| EVP_PKEY_fromdata(ctx, &pkey, EVP_PKEY_KEYPAIR, params) <= 0) {
exitcode = 1;
} else {
/* Do what you want with |pkey| */
}
EVP_PKEY_free(pkey);
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
OSSL_PARAM_BLD_free(param_bld);
BN_free(priv);
exit(exitcode);
}
#include <openssl/evp.h>
#include <openssl/core.h>
/* Program expects a key type as first argument */
int main(int argc, char *argv[])
{
EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new_from_name(NULL, argv[1], NULL);
const OSSL_PARAM *settable_params = NULL;
if (ctx == NULL)
exit(1);
settable_params = EVP_PKEY_fromdata_settable(ctx, EVP_PKEY_KEYPAIR);
if (settable_params == NULL)
exit(1);
for (; settable_params->key != NULL; settable_params++) {
const char *datatype = NULL;
switch (settable_params->data_type) {
case OSSL_PARAM_INTEGER:
datatype = "integer";
break;
case OSSL_PARAM_UNSIGNED_INTEGER:
datatype = "unsigned integer";
break;
case OSSL_PARAM_UTF8_STRING:
datatype = "printable string (utf-8 encoding expected)";
break;
case OSSL_PARAM_UTF8_PTR:
datatype = "printable string pointer (utf-8 encoding expected)";
break;
case OSSL_PARAM_OCTET_STRING:
datatype = "octet string";
break;
case OSSL_PARAM_OCTET_PTR:
datatype = "octet string pointer";
break;
}
printf("%s : %s ", settable_params->key, datatype);
if (settable_params->data_size == 0)
printf("(unlimited size)\n");
else
printf("(maximum size %zu)\n", settable_params->data_size);
}
}
The descriptor OSSL_PARAM(3) returned by EVP_PKEY_fromdata_settable() may also be used programmatically, for example with OSSL_PARAM_allocate_from_text(3).
Licensed under the Apache License 2.0 (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 <https://www.openssl.org/source/license.html>.
| 2023-05-07 | 3.0.12 |