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OSSL_CMP_exec_certreq(3) OpenSSL OSSL_CMP_exec_certreq(3)
NAME
OSSL_CMP_exec_certreq, OSSL_CMP_exec_IR_ses, OSSL_CMP_exec_CR_ses,
OSSL_CMP_exec_P10CR_ses, OSSL_CMP_exec_KUR_ses, OSSL_CMP_IR,
OSSL_CMP_CR, OSSL_CMP_P10CR, OSSL_CMP_KUR, OSSL_CMP_try_certreq,
OSSL_CMP_exec_RR_ses, OSSL_CMP_exec_GENM_ses - functions implementing
CMP client transactions
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
#include <openssl/cmp.h>
X509 *OSSL_CMP_exec_certreq(OSSL_CMP_CTX *ctx, int req_type,
const OSSL_CRMF_MSG *crm);
X509 *OSSL_CMP_exec_IR_ses(OSSL_CMP_CTX *ctx);
X509 *OSSL_CMP_exec_CR_ses(OSSL_CMP_CTX *ctx);
X509 *OSSL_CMP_exec_P10CR_ses(OSSL_CMP_CTX *ctx);
X509 *OSSL_CMP_exec_KUR_ses(OSSL_CMP_CTX *ctx);
#define OSSL_CMP_IR
#define OSSL_CMP_CR
#define OSSL_CMP_P10CR
#define OSSL_CMP_KUR
int OSSL_CMP_try_certreq(OSSL_CMP_CTX *ctx, int req_type,
const OSSL_CRMF_MSG *crm, int *checkAfter);
int OSSL_CMP_exec_RR_ses(OSSL_CMP_CTX *ctx);
STACK_OF(OSSL_CMP_ITAV) *OSSL_CMP_exec_GENM_ses(OSSL_CMP_CTX *ctx);
DESCRIPTION
This is the OpenSSL API for doing CMP (Certificate Management Protocol)
client-server transactions, i.e., sequences of CMP requests and
responses.
All functions take a populated OSSL_CMP_CTX structure as their first
argument. Usually the server name, port, and path ("CMP alias") need
to be set, as well as credentials the client can use for authenticating
itself to the server. In order to authenticate the server the client
typically needs a trust store. The functions return their respective
main results directly, while there are also accessor functions for
retrieving various results and status information from the ctx. See
OSSL_CMP_CTX_new(3) etc. for details.
The default conveying protocol is HTTP. Timeout values may be given per
request-response pair and per transaction. See
OSSL_CMP_MSG_http_perform(3) for details.
OSSL_CMP_exec_IR_ses() requests an initial certificate from the given
PKI.
OSSL_CMP_exec_CR_ses() requests an additional certificate.
OSSL_CMP_exec_P10CR_ses() conveys a legacy PKCS#10 CSR requesting a
certificate.
OSSL_CMP_exec_KUR_ses() obtains an updated certificate.
These four types of certificate enrollment are implemented as macros
calling OSSL_CMP_exec_certreq().
OSSL_CMP_exec_certreq() performs a certificate request of the type
specified by the req_type parameter, which may be IR, CR, P10CR, or
KUR. For IR, CR, and KUR, the certificate template to be used in the
request may be supplied via the crm parameter pointing to a CRMF
structure. Typically crm is NULL, then the template ingredients are
taken from ctx and need to be filled in using
OSSL_CMP_CTX_set1_subjectName(3), OSSL_CMP_CTX_set0_newPkey(3),
OSSL_CMP_CTX_set1_oldCert(3), etc. For P10CR,
OSSL_CMP_CTX_set1_p10CSR(3) needs to be used instead. The enrollment
session may be blocked by sleeping until the addressed CA (or an
intermediate PKI component) can fully process and answer the request.
OSSL_CMP_try_certreq() is an alternative to the above functions that is
more flexible regarding what to do after receiving a checkAfter value.
When called for the first time (with no certificate request in progress
for the given ctx) it starts a new transaction by sending a certificate
request constructed as stated above using the req_type and optional crm
parameter. Otherwise (when according to ctx a 'waiting' status has
been received before) it continues polling for the pending request
unless the req_type argument is < 0, which aborts the request. If the
requested certificate is available the function returns 1 and the
caller can use OSSL_CMP_CTX_get0_newCert(3) to retrieve the new
certificate. If no error occurred but no certificate is available yet
then OSSL_CMP_try_certreq() remembers in the CMP context that it should
be retried and returns -1 after assigning the received checkAfter value
via the output pointer argument (unless it is NULL). The checkAfter
value indicates the number of seconds the caller should let pass before
trying again. The caller is free to sleep for the given number of
seconds or for some other time and/or to do anything else before
retrying by calling OSSL_CMP_try_certreq() again with the same
parameter values as before. OSSL_CMP_try_certreq() then polls to see
whether meanwhile the requested certificate is available. If the
caller decides to abort the pending certificate request and provides a
negative value as the req_type argument then OSSL_CMP_try_certreq()
aborts the CMP transaction by sending an error message to the server.
OSSL_CMP_exec_RR_ses() requests the revocation of the certificate
specified in the ctx using OSSL_CMP_CTX_set1_oldCert(3). RFC 4210 is
vague in which PKIStatus should be returned by the server. We take
"accepted" and "grantedWithMods" as clear success and handle
"revocationWarning" and "revocationNotification" just as warnings
because CAs typically return them as an indication that the certificate
was already revoked. "rejection" is a clear error. The values
"waiting" and "keyUpdateWarning" make no sense for revocation and thus
are treated as an error as well.
OSSL_CMP_exec_GENM_ses() sends a general message containing the
sequence of infoType and infoValue pairs (InfoTypeAndValue; short:
ITAV) optionally provided in the ctx using
OSSL_CMP_CTX_push0_genm_ITAV(3). On success it records in ctx the
status OSSL_CMP_PKISTATUS_accepted and returns the list of ITAVs
received in the GENP message. This can be used, for instance, to poll
for CRLs or CA Key Updates. See RFC 4210 section 5.3.19 and appendix
E.5 for details.
NOTES
CMP is defined in RFC 4210 (and CRMF in RFC 4211).
The CMP client implementation is limited to one request per CMP message
(and consequently to at most one response component per CMP message).
When a client obtains from a CMP server CA certificates that it is
going to trust, for instance via the caPubs field of a certificate
response, authentication of the CMP server is particularly critical.
So special care must be taken setting up server authentication in ctx
using functions such as OSSL_CMP_CTX_set0_trustedStore(3) (for
certificate-based authentication) or OSSL_CMP_CTX_set1_secretValue(3)
(for MAC-based protection).
RETURN VALUES
OSSL_CMP_exec_certreq(), OSSL_CMP_exec_IR_ses(),
OSSL_CMP_exec_CR_ses(), OSSL_CMP_exec_P10CR_ses(), and
OSSL_CMP_exec_KUR_ses() return a pointer to the newly obtained X509
certificate on success, NULL on error. This pointer will be freed
implicitly by OSSL_CMP_CTX_free() or CSSL_CMP_CTX_reinit().
OSSL_CMP_try_certreq() returns 1 if the requested certificate is
available via OSSL_CMP_CTX_get0_newCert(3) or on successfully aborting
a pending certificate request, 0 on error, and -1 in case a 'waiting'
status has been received and checkAfter value is available. In the
latter case OSSL_CMP_CTX_get0_newCert(3) yields NULL and the output
parameter checkAfter has been used to assign the received value unless
checkAfter is NULL.
OSSL_CMP_exec_RR_ses() returns 1 on success, 0 on error.
OSSL_CMP_exec_GENM_ses() returns NULL on error, otherwise a pointer to
the sequence of ITAV received, which may be empty. This pointer must
be freed by the caller.
EXAMPLES
See OSSL_CMP_CTX for examples on how to prepare the context for these
functions.
SEE ALSO
OSSL_CMP_CTX_new(3), OSSL_CMP_CTX_free(3),
OSSL_CMP_CTX_set1_subjectName(3), OSSL_CMP_CTX_set0_newPkey(3),
OSSL_CMP_CTX_set1_p10CSR(3), OSSL_CMP_CTX_set1_oldCert(3),
OSSL_CMP_CTX_get0_newCert(3), OSSL_CMP_CTX_push0_genm_ITAV(3),
OSSL_CMP_MSG_http_perform(3)
HISTORY
The OpenSSL CMP support was added in OpenSSL 3.0.
COPYRIGHT
Copyright 2007-2023 The OpenSSL Project Authors. All Rights Reserved.
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>.
3.0.12 2023-10-25 OSSL_CMP_exec_certreq(3)