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Diffstat (limited to 'doc/man3/EVP_PKEY_CTX_ctrl.pod')
| -rw-r--r-- | doc/man3/EVP_PKEY_CTX_ctrl.pod | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/doc/man3/EVP_PKEY_CTX_ctrl.pod b/doc/man3/EVP_PKEY_CTX_ctrl.pod new file mode 100644 index 000000000000..e1a107c06e3c --- /dev/null +++ b/doc/man3/EVP_PKEY_CTX_ctrl.pod @@ -0,0 +1,211 @@ +=pod + +=head1 NAME + +EVP_PKEY_CTX_ctrl, +EVP_PKEY_CTX_ctrl_str, +EVP_PKEY_CTX_set_signature_md, +EVP_PKEY_CTX_get_signature_md, +EVP_PKEY_CTX_set_mac_key, +EVP_PKEY_CTX_set_rsa_padding, +EVP_PKEY_CTX_set_rsa_pss_saltlen, +EVP_PKEY_CTX_set_rsa_keygen_bits, +EVP_PKEY_CTX_set_rsa_keygen_pubexp, +EVP_PKEY_CTX_set_dsa_paramgen_bits, +EVP_PKEY_CTX_set_dh_paramgen_prime_len, +EVP_PKEY_CTX_set_dh_paramgen_generator, +EVP_PKEY_CTX_set_dh_pad, +EVP_PKEY_CTX_set_dh_nid, +EVP_PKEY_CTX_set_ec_paramgen_curve_nid, +EVP_PKEY_CTX_set_ec_param_enc, +EVP_PKEY_CTX_set1_id, EVP_PKEY_CTX_get1_id, EVP_PKEY_CTX_get1_id_len +- algorithm specific control operations + +=head1 SYNOPSIS + + #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_CTX_set_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD *md); + int EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD **pmd); + + int EVP_PKEY_CTX_set_mac_key(EVP_PKEY_CTX *ctx, unsigned char *key, int len); + + #include <openssl/rsa.h> + + 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_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); + int EVP_PKEY_CTX_set_dh_pad(EVP_PKEY_CTX *ctx, int pad); + int EVP_PKEY_CTX_set_dh_nid(EVP_PKEY_CTX *ctx, int nid); + + #include <openssl/ec.h> + int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid); + int EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int param_enc); + + int EVP_PKEY_CTX_set1_id(EVP_PKEY_CTX *ctx, void *id, size_t id_len); + int EVP_PKEY_CTX_get1_id(EVP_PKEY_CTX *ctx, void *id); + int EVP_PKEY_CTX_get1_id_len(EVP_PKEY_CTX *ctx, size_t *id_len); + +=head1 DESCRIPTION + +The function EVP_PKEY_CTX_ctrl() sends a control operation to the context +B<ctx>. The key type used must match B<keytype> if it is not -1. The parameter +B<optype> is a mask indicating which operations the control can be applied to. +The control command is indicated in B<cmd> and any additional arguments in +B<p1> and B<p2>. + +For B<cmd> = B<EVP_PKEY_CTRL_SET_MAC_KEY>, B<p1> is the length of the MAC key, +and B<p2> is MAC key. This is used by Poly1305, SipHash, HMAC and CMAC. + +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_CTX_ctrl_str() allows an application to send an algorithm +specific control operation to a context B<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 B<-pkeyopt> which is supported by the +B<pkeyutl>, B<genpkey> and B<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 in the RSA, DSA and ECDSA algorithms. + +The EVP_PKEY_CTX_get_signature_md() macro gets the message digest type used in a +signature. It can be used in the RSA, DSA and ECDSA algorithms. + +Key generation typically involves setting up parameters to be used and +generating the private and public key data. Some algorithm implementations +allow private key data to be set explicitly using the EVP_PKEY_CTX_set_mac_key() +macro. In this case key generation is simply the process of setting up the +parameters for the key and then setting the raw key data to the value explicitly +provided by that macro. Normally applications would call +L<EVP_PKEY_new_raw_private_key(3)> or similar functions instead of this macro. + +The EVP_PKEY_CTX_set_mac_key() macro can be used with any of the algorithms +supported by the L<EVP_PKEY_new_raw_private_key(3)> function. + +The macro EVP_PKEY_CTX_set_rsa_padding() sets the RSA padding mode for B<ctx>. +The B<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 +B<len> as its name implies it is only supported for PSS padding. Three special +values are supported: RSA_PSS_SALTLEN_DIGEST sets the salt length to the +digest length, RSA_PSS_SALTLEN_MAX sets the salt length to the maximum +permissible value. When verifying RSA_PSS_SALTLEN_AUTO causes the salt length +to be automatically determined based on the B<PSS> block structure. If this +macro is not called maximum salt length is used when signing and auto detection +when verifying is used by default. + +The EVP_PKEY_CTX_set_rsa_keygen_bits() macro sets the RSA key length for +RSA key generation to B<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 B<pubexp> currently it should be an odd integer. The +B<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 B<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 B<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 B<gen> +for DH parameter generation. If not specified 2 is used. + +The EVP_PKEY_CTX_set_dh_pad() macro sets the DH padding mode. If B<pad> is +1 the shared secret is padded with zeroes up to the size of the DH prime B<p>. +If B<pad> is zero (the default) then no padding is performed. + +EVP_PKEY_CTX_set_dh_nid() sets the DH parameters to values corresponding to +B<nid>. The B<nid> parameter must be B<NID_ffdhe2048>, B<NID_ffdhe3072>, +B<NID_ffdhe4096>, B<NID_ffdhe6144> or B<NID_ffdhe8192>. This macro can be +called during parameter or key generation. + +The EVP_PKEY_CTX_set_ec_paramgen_curve_nid() sets the EC curve for EC parameter +generation to B<nid>. For EC parameter generation this macro must be called +or an error occurs because there is no default curve. +This function can also be called to set the curve explicitly when +generating an EC key. + +The EVP_PKEY_CTX_set_ec_param_enc() sets the EC parameter encoding to +B<param_enc> when generating EC parameters or an EC key. The encoding can be +B<OPENSSL_EC_EXPLICIT_CURVE> for explicit parameters (the default in versions +of OpenSSL before 1.1.0) or B<OPENSSL_EC_NAMED_CURVE> to use named curve form. +For maximum compatibility the named curve form should be used. Note: the +B<OPENSSL_EC_NAMED_CURVE> value was only added to OpenSSL 1.1.0; previous +versions should use 0 instead. + +The EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and EVP_PKEY_CTX_get1_id_len() +macros are used to manipulate the special identifier field for specific signature +algorithms such as SM2. The EVP_PKEY_CTX_set1_id() sets an ID pointed by B<id> with +the length B<id_len> to the library. The library takes a copy of the id so that +the caller can safely free the original memory pointed to by B<id>. The +EVP_PKEY_CTX_get1_id_len() macro returns the length of the ID set via a previous +call to EVP_PKEY_CTX_set1_id(). The length is usually used to allocate adequate +memory for further calls to EVP_PKEY_CTX_get1_id(). The EVP_PKEY_CTX_get1_id() +macro returns the previously set ID value to caller in B<id>. The caller should +allocate adequate memory space for the B<id> before calling EVP_PKEY_CTX_get1_id(). + +=head1 RETURN VALUES + +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. + +=head1 SEE ALSO + +L<EVP_PKEY_CTX_new(3)>, +L<EVP_PKEY_encrypt(3)>, +L<EVP_PKEY_decrypt(3)>, +L<EVP_PKEY_sign(3)>, +L<EVP_PKEY_verify(3)>, +L<EVP_PKEY_verify_recover(3)>, +L<EVP_PKEY_derive(3)> +L<EVP_PKEY_keygen(3)> + +=head1 HISTORY + +EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and EVP_PKEY_CTX_get1_id_len() +macros were added in 1.1.1, other functions were first added to OpenSSL 1.0.0. + +=head1 COPYRIGHT + +Copyright 2006-2018 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 |