\s+
|
|sg]] [[s|
\s+\s*
EVP_PKEY_ctrl, EVP_PKEY_ctrl_str - algorithm specific control operations
#include <openssl/evp.h>
int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,
int cmd, int p1, void *p2);
int EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
const char *value);
int EVP_PKEY_get_default_digest_nid(EVP_PKEY *pkey, int *pnid);
#include <openssl/rsa.h>
int EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int pad); int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int len); int EVP_PKEY_CTX_set_rsa_rsa_keygen_bits(EVP_PKEY_CTX *ctx, int mbits); int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
#include <openssl/dsa.h> int EVP_PKEY_CTX_set_dsa_paramgen_bits(EVP_PKEY_CTX *ctx, int nbits);
#include <openssl/dh.h> int EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int len); int EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen);
#include <openssl/ec.h> int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid);
The function EVP_PKEY_CTX_ctrl() sends a control operation to
the context
ctx. The key type used must match keytype if it is not -1. The parameter
optype is a mask indicating which operations the control can be applied to. The
control command is indicated in cmd and any additional arguments in
p1 and p2.
Applications will not normally call EVP_PKEY_CTX_ctrl()
directly but will instead call one of the algorithm specific macros below.
The function EVP_PKEY_ctrl_str() allows an application to send
an algorithm specific control operation to a context ctx in string form. This is intended to be used for options specified on the
command line or in text files. The commands supported are documented in the
openssl utility command line pages for the option -pkeyopt which is supported by the
pkeyutl, genpkey and req commands.
All the remaining ``functions'' are implemented as macros.
The EVP_PKEY_CTX_set_signature_md() macro sets the message
digest type used in a signature. It can be used with any public key
algorithm supporting signature operations.
The macro EVP_PKEY_CTX_set_rsa_padding() sets the RSA padding
mode for ctx. The pad parameter can take the value RSA_PKCS1_PADDING for PKCS#1 padding,
RSA_SSLV23_PADDING for SSLv23 padding, RSA_NO_PADDING for no padding,
RSA_PKCS1_OAEP_PADDING for OAEP padding (encrypt and decrypt only),
RSA_X931_PADDING for X9.31 padding (signature operations only) and
RSA_PKCS1_PSS_PADDING (sign and verify only).
Two RSA padding modes behave differently if
EVP_PKEY_CTX_set_signature_md() is used. If this macro is
called for PKCS#1 padding the plaintext buffer is an actual digest value
and is encapsulated in a DigestInfo structure according to PKCS#1 when
signing and this structure is expected (and stripped off) when verifying.
If this control is not used with RSA and PKCS#1 padding then the supplied
data is used directly and not encapsulated. In the case of X9.31 padding
for RSA the algorithm identifier byte is added or checked and removed if
this control is called. If it is not called then the first byte of the
plaintext buffer is expected to be the algorithm identifier byte.
The EVP_PKEY_CTX_set_rsa_pss_saltlen() macro sets the RSA PSS
salt length to
len as its name implies it is only supported for PSS padding. Two special
values are supported: -1 sets the salt length to the digest length. When
signing -2 sets the salt length to the maximum permissible value. When
verifying -2 causes the salt length to be automatically determined based on
the
PSS block structure. If this macro is not called a salt length value of -2 is
used by default.
The EVP_PKEY_CTX_set_rsa_rsa_keygen_bits() macro sets the RSA
key length for RSA key genration to bits. If not specified 1024 bits is used.
The EVP_PKEY_CTX_set_rsa_keygen_pubexp() macro sets the public
exponent value for RSA key generation to pubexp currently it should be an odd integer. The
pubexp pointer is used internally by this function so it should not be modified or
free after the call. If this macro is not called then 65537 is used.
The macro EVP_PKEY_CTX_set_dsa_paramgen_bits() sets the number
of bits used for DSA parameter generation to bits. If not specified 1024 is used.
The macro EVP_PKEY_CTX_set_dh_paramgen_prime_len() sets the
length of the DH prime parameter p for DH parameter generation. If this macro is not called then 1024 is used.
The EVP_PKEY_CTX_set_dh_paramgen_generator() macro sets DH
generator to gen
for DH parameter generation. If not specified 2 is used.
The EVP_PKEY_CTX_set_ec_paramgen_curve_nid() sets the EC curve
for EC parameter generation to nid. For EC parameter generation this macro must be called or an error occurs
because there is no default curve.
EVP_PKEY_CTX_ctrl() and its macros return a positive value for
success and 0 or a negative value for failure. In particular a return value
of -2 indicates the operation is not supported by the public key algorithm.
EVP_PKEY_CTX_new(3), EVP_PKEY_encrypt(3), EVP_PKEY_decrypt(3), EVP_PKEY_sign(3), EVP_PKEY_verify(3), EVP_PKEY_verify_recover(3), EVP_PKEY_derive(3) EVP_PKEY_keygen(3)
These functions were first added to OpenSSL 1.0.0.
:}