Chunk 10 of CMP contribution to OpenSSL: CMP http client and related tests

    Also improve the generic HTTP client w.r.t. proxy and no_proxy options.

    Certificate Management Protocol (CMP, RFC 4210) extension to OpenSSL
    Also includes CRMF (RFC 4211) and HTTP transfer (RFC 6712).
    Adds the CMP and CRMF API to libcrypto and the "cmp" app to the CLI.
    Adds extensive documentation and tests.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: David von Oheimb <david.von.oheimb@siemens.com>
(Merged from https://github.com/openssl/openssl/pull/11404)

5 files changed, 106 insertions, 150 deletions

diff --git a/crypto/cmp/build.info b/crypto/cmp/build.info
index d3fbae2452..a2a57c14ec 100644
--- a/crypto/cmp/build.info
+++ b/crypto/cmp/build.info
@@ -1,4 +1,4 @@
 LIBS=../../libcrypto
 SOURCE[../../libcrypto]= cmp_asn.c cmp_ctx.c cmp_err.c cmp_util.c \
         cmp_status.c cmp_hdr.c cmp_protect.c cmp_msg.c cmp_vfy.c \
-        cmp_server.c cmp_client.c
+        cmp_server.c cmp_client.c cmp_http.c
diff --git a/crypto/cmp/cmp_client.c b/crypto/cmp/cmp_client.c
index eedabc59d2..604b4ce9a1 100644
--- a/crypto/cmp/cmp_client.c
+++ b/crypto/cmp/cmp_client.c
@@ -140,7 +140,7 @@ static int send_receive_check(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *req,
     OSSL_CMP_transfer_cb_t transfer_cb = ctx->transfer_cb;
 
     if (transfer_cb == NULL)
-        transfer_cb = NULL; /* TODO: will be OSSL_CMP_MSG_http_perform of chunk 10 */
+        transfer_cb = OSSL_CMP_MSG_http_perform;
 
     *rep = NULL;
     msg_timeout = ctx->msg_timeout; /* backup original value */
diff --git a/crypto/cmp/cmp_ctx.c b/crypto/cmp/cmp_ctx.c
index 873d69320e..eb799b103c 100644
--- a/crypto/cmp/cmp_ctx.c
+++ b/crypto/cmp/cmp_ctx.c
@@ -20,9 +20,7 @@
 #include <openssl/crmf.h>
 #include <openssl/err.h>
 
-/*
- * Get current certificate store containing trusted root CA certs
- */
+/* Get current certificate store containing trusted root CA certs */
 X509_STORE *OSSL_CMP_CTX_get0_trustedStore(const OSSL_CMP_CTX *ctx)
 {
     if (ctx == NULL) {
@@ -36,7 +34,6 @@ X509_STORE *OSSL_CMP_CTX_get0_trustedStore(const OSSL_CMP_CTX *ctx)
  * Set certificate store containing trusted (root) CA certs and possibly CRLs
  * and a cert verification callback function used for CMP server authentication.
  * Any already existing store entry is freed. Given NULL, the entry is reset.
- * returns 1 on success, 0 on error
  */
 int OSSL_CMP_CTX_set0_trustedStore(OSSL_CMP_CTX *ctx, X509_STORE *store)
 {
@@ -49,9 +46,7 @@ int OSSL_CMP_CTX_set0_trustedStore(OSSL_CMP_CTX *ctx, X509_STORE *store)
     return 1;
 }
 
-/*
- * Get current list of non-trusted intermediate certs
- */
+/* Get current list of non-trusted intermediate certs */
 STACK_OF(X509) *OSSL_CMP_CTX_get0_untrusted_certs(const OSSL_CMP_CTX *ctx)
 {
     if (ctx == NULL) {
@@ -64,7 +59,6 @@ STACK_OF(X509) *OSSL_CMP_CTX_get0_untrusted_certs(const OSSL_CMP_CTX *ctx)
 /*
  * Set untrusted certificates for path construction in authentication of
  * the CMP server and potentially others (TLS server, newly enrolled cert).
- * returns 1 on success, 0 on error
  */
 int OSSL_CMP_CTX_set1_untrusted_certs(OSSL_CMP_CTX *ctx, STACK_OF(X509) *certs)
 {
@@ -102,7 +96,6 @@ OSSL_CMP_CTX *OSSL_CMP_CTX_new(void)
     ctx->failInfoCode = -1;
 
     ctx->serverPort = OSSL_CMP_DEFAULT_PORT;
-    ctx->proxyPort = OSSL_CMP_DEFAULT_PORT;
     ctx->msg_timeout = 2 * 60;
 
     if ((ctx->untrusted_certs = sk_X509_new_null()) == NULL)
@@ -125,9 +118,7 @@ OSSL_CMP_CTX *OSSL_CMP_CTX_new(void)
     return NULL;
 }
 
-/*
- * Prepare the OSSL_CMP_CTX for next use, partly re-initializing OSSL_CMP_CTX
- */
+/* Prepare the OSSL_CMP_CTX for next use, partly re-initializing OSSL_CMP_CTX */
 int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx)
 {
     if (ctx == NULL) {
@@ -148,9 +139,7 @@ int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx)
         && ossl_cmp_ctx_set1_recipNonce(ctx, NULL);
 }
 
-/*
- * Frees OSSL_CMP_CTX variables allocated in OSSL_CMP_CTX_new()
- */
+/* Frees OSSL_CMP_CTX variables allocated in OSSL_CMP_CTX_new() */
 void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx)
 {
     if (ctx == NULL)
@@ -158,7 +147,8 @@ void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx)
 
     OPENSSL_free(ctx->serverPath);
     OPENSSL_free(ctx->serverName);
-    OPENSSL_free(ctx->proxyName);
+    OPENSSL_free(ctx->proxy);
+    OPENSSL_free(ctx->no_proxy);
 
     X509_free(ctx->srvCert);
     X509_free(ctx->validatedSrvCert);
@@ -252,11 +242,7 @@ int ossl_cmp_ctx_set0_validatedSrvCert(OSSL_CMP_CTX *ctx, X509 *cert)
     return 1;
 }
 
-/*
- * Set callback function for checking if the cert is ok or should
- * it be rejected.
- * Returns 1 on success, 0 on error
- */
+/* Set callback function for checking if the cert is ok or should be rejected */
 int OSSL_CMP_CTX_set_certConf_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_certConf_cb_t cb)
 {
     if (ctx == NULL) {
@@ -270,7 +256,6 @@ int OSSL_CMP_CTX_set_certConf_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_certConf_cb_t cb)
 /*
  * Set argument, respectively a pointer to a structure containing arguments,
  * optionally to be used by the certConf callback.
- * Returns 1 on success, 0 on error
  */
 int OSSL_CMP_CTX_set_certConf_cb_arg(OSSL_CMP_CTX *ctx, void *arg)
 {
@@ -380,10 +365,7 @@ int ossl_cmp_print_log(OSSL_CMP_severity level, const OSSL_CMP_CTX *ctx,
     return res;
 }
 
-/*
- * Set a callback function for error reporting and logging messages.
- * Returns 1 on success, 0 on error
- */
+/* Set a callback function for error reporting and logging messages */
 int OSSL_CMP_CTX_set_log_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_log_cb_t cb)
 {
     if (ctx == NULL) {
@@ -411,7 +393,6 @@ void OSSL_CMP_CTX_print_errors(OSSL_CMP_CTX *ctx)
 /*
  * Set or clear the reference value to be used for identification
  * (i.e., the user name) when using PBMAC.
- * Returns 1 on success, 0 on error
  */
 int OSSL_CMP_CTX_set1_referenceValue(OSSL_CMP_CTX *ctx,
                                      const unsigned char *ref, int len)
@@ -424,10 +405,7 @@ int OSSL_CMP_CTX_set1_referenceValue(OSSL_CMP_CTX *ctx,
                                                  len);
 }
 
-/*
- * Set or clear the password to be used for protecting messages with PBMAC.
- * Returns 1 on success, 0 on error
- */
+/* Set or clear the password to be used for protecting messages with PBMAC */
 int OSSL_CMP_CTX_set1_secretValue(OSSL_CMP_CTX *ctx, const unsigned char *sec,
                                   const int len)
 {
@@ -465,7 +443,6 @@ STACK_OF(X509) *OSSL_CMP_CTX_get1_extraCertsIn(const OSSL_CMP_CTX *ctx)
 /*
  * Copies any given stack of inbound X509 certificates to extraCertsIn
  * of the OSSL_CMP_CTX structure so that they may be retrieved later.
- * Returns 1 on success, 0 on error.
  */
 int ossl_cmp_ctx_set1_extraCertsIn(OSSL_CMP_CTX *ctx,
                                    STACK_OF(X509) *extraCertsIn)
@@ -483,7 +460,6 @@ int ossl_cmp_ctx_set1_extraCertsIn(OSSL_CMP_CTX *ctx,
 /*
  * Duplicate and set the given stack as the new stack of X509
  * certificates to send out in the extraCerts field.
- * Returns 1 on success, 0 on error
  */
 int OSSL_CMP_CTX_set1_extraCertsOut(OSSL_CMP_CTX *ctx,
                                     STACK_OF(X509) *extraCertsOut)
@@ -503,7 +479,6 @@ int OSSL_CMP_CTX_set1_extraCertsOut(OSSL_CMP_CTX *ctx,
 /*
  * Add the given policy info object
  * to the X509_EXTENSIONS of the requested certificate template.
- * Returns 1 on success, 0 on error.
  */
 int OSSL_CMP_CTX_push0_policy(OSSL_CMP_CTX *ctx, POLICYINFO *pinfo)
 {
@@ -519,9 +494,7 @@ int OSSL_CMP_CTX_push0_policy(OSSL_CMP_CTX *ctx, POLICYINFO *pinfo)
     return sk_POLICYINFO_push(ctx->policies, pinfo);
 }
 
-/*
- * Add an ITAV for geninfo of the PKI message header
- */
+/* Add an ITAV for geninfo of the PKI message header */
 int OSSL_CMP_CTX_push0_geninfo_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav)
 {
     if (ctx == NULL) {
@@ -531,9 +504,7 @@ int OSSL_CMP_CTX_push0_geninfo_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav)
     return OSSL_CMP_ITAV_push0_stack_item(&ctx->geninfo_ITAVs, itav);
 }
 
-/*
- * Add an itav for the body of outgoing general messages
- */
+/* Add an itav for the body of outgoing general messages */
 int OSSL_CMP_CTX_push0_genm_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav)
 {
     if (ctx == NULL) {
@@ -562,7 +533,6 @@ STACK_OF(X509) *OSSL_CMP_CTX_get1_caPubs(const OSSL_CMP_CTX *ctx)
 /*
  * Duplicate and copy the given stack of certificates to the given
  * OSSL_CMP_CTX structure so that they may be retrieved later.
- * Returns 1 on success, 0 on error
  */
 int ossl_cmp_ctx_set1_caPubs(OSSL_CMP_CTX *ctx, STACK_OF(X509) *caPubs)
 {
@@ -614,39 +584,25 @@ int OSSL_CMP_CTX_set1_##FIELD(OSSL_CMP_CTX *ctx, TYPE *val) \
  * Pins the server certificate to be directly trusted (even if it is expired)
  * for verifying response messages.
  * Cert pointer is not consumed. It may be NULL to clear the entry.
- * Returns 1 on success, 0 on error
  */
 DEFINE_OSSL_CMP_CTX_set1_up_ref(srvCert, X509)
 
-/*
- * Set the X509 name of the recipient. Set in the PKIHeader.
- * returns 1 on success, 0 on error
- */
+/* Set the X509 name of the recipient. Set in the PKIHeader */
 DEFINE_OSSL_CMP_CTX_set1(recipient, X509_NAME)
 
-/*
- * Store the X509 name of the expected sender in the PKIHeader of responses.
- * Returns 1 on success, 0 on error
- */
+/* Store the X509 name of the expected sender in the PKIHeader of responses */
 DEFINE_OSSL_CMP_CTX_set1(expected_sender, X509_NAME)
 
-/*
- * Set the X509 name of the issuer. Set in the PKIHeader.
- * Returns 1 on success, 0 on error
- */
+/* Set the X509 name of the issuer. Set in the PKIHeader */
 DEFINE_OSSL_CMP_CTX_set1(issuer, X509_NAME)
 
 /*
  * Set the subject name that will be placed in the certificate
  * request. This will be the subject name on the received certificate.
- * Returns 1 on success, 0 on error
  */
 DEFINE_OSSL_CMP_CTX_set1(subjectName, X509_NAME)
 
-/*
- * Set the X.509v3 certificate request extensions to be used in IR/CR/KUR.
- * Returns 1 on success, 0 on error
- */
+/* Set the X.509v3 certificate request extensions to be used in IR/CR/KUR */
 int OSSL_CMP_CTX_set0_reqExtensions(OSSL_CMP_CTX *ctx, X509_EXTENSIONS *exts)
 {
     if (ctx == NULL) {
@@ -680,7 +636,6 @@ int OSSL_CMP_CTX_reqExtensions_have_SAN(OSSL_CMP_CTX *ctx)
 /*
  * Add a GENERAL_NAME structure that will be added to the CRMF
  * request's extensions field to request subject alternative names.
- * Returns 1 on success, 0 on error
  */
 int OSSL_CMP_CTX_push1_subjectAltName(OSSL_CMP_CTX *ctx,
                                       const GENERAL_NAME *name)
@@ -712,7 +667,6 @@ int OSSL_CMP_CTX_push1_subjectAltName(OSSL_CMP_CTX *ctx,
 /*
  * Set our own client certificate, used for example in KUR and when
  * doing the IR with existing certificate.
- * Returns 1 on success, 0 on error
  */
 DEFINE_OSSL_CMP_CTX_set1_up_ref(clCert, X509)
 
@@ -721,19 +675,14 @@ DEFINE_OSSL_CMP_CTX_set1_up_ref(clCert, X509)
  * or the certificate to be revoked in RR, respectively.
  * Also used as reference cert (defaulting to clCert) for deriving subject DN
  * and SANs. Its issuer is used as default recipient in the CMP message header.
- * Returns 1 on success, 0 on error
  */
 DEFINE_OSSL_CMP_CTX_set1_up_ref(oldCert, X509)
 
-/*
- * Set the PKCS#10 CSR to be sent in P10CR.
- * Returns 1 on success, 0 on error
- */
+/* Set the PKCS#10 CSR to be sent in P10CR */
 DEFINE_OSSL_CMP_CTX_set1(p10CSR, X509_REQ)
 
 /*
- * Sets the (newly received in IP/KUP/CP) certificate in the context.
- * Returns 1 on success, 0 on error
+ * Set the (newly received in IP/KUP/CP) certificate in the context.
  * TODO: this only permits for one cert to be enrolled at a time.
  */
 int ossl_cmp_ctx_set0_newCert(OSSL_CMP_CTX *ctx, X509 *cert)
@@ -759,16 +708,10 @@ X509 *OSSL_CMP_CTX_get0_newCert(const OSSL_CMP_CTX *ctx)
     return ctx->newCert;
 }
 
-/*
- * Set the client's current private key.
- * Returns 1 on success, 0 on error
- */
+/* Set the client's current private key */
 DEFINE_OSSL_CMP_CTX_set1_up_ref(pkey, EVP_PKEY)
 
-/*
- * Set new key pair. Used e.g. when doing Key Update.
- * Returns 1 on success, 0 on error
- */
+/* Set new key pair. Used e.g. when doing Key Update */
 int OSSL_CMP_CTX_set0_newPkey(OSSL_CMP_CTX *ctx, int priv, EVP_PKEY *pkey)
 {
     if (ctx == NULL) {
@@ -782,9 +725,7 @@ int OSSL_CMP_CTX_set0_newPkey(OSSL_CMP_CTX *ctx, int priv, EVP_PKEY *pkey)
     return 1;
 }
 
-/*
- * gets the private/public key to use for certificate enrollment, NULL on error
- */
+/* Get the private/public key to use for cert enrollment, or NULL on error */
 EVP_PKEY *OSSL_CMP_CTX_get0_newPkey(const OSSL_CMP_CTX *ctx, int priv)
 {
     if (ctx == NULL) {
@@ -799,10 +740,7 @@ EVP_PKEY *OSSL_CMP_CTX_get0_newPkey(const OSSL_CMP_CTX *ctx, int priv)
     return ctx->pkey; /* may be NULL */
 }
 
-/*
- * Sets the given transactionID to the context.
- * Returns 1 on success, 0 on error
- */
+/* Set the given transactionID to the context */
 int OSSL_CMP_CTX_set1_transactionID(OSSL_CMP_CTX *ctx,
                                     const ASN1_OCTET_STRING *id)
 {
@@ -813,11 +751,7 @@ int OSSL_CMP_CTX_set1_transactionID(OSSL_CMP_CTX *ctx,
     return ossl_cmp_asn1_octet_string_set1(&ctx->transactionID, id);
 }
 
-/*
- * sets the given nonce to be used for the recipNonce in the next message to be
- * created.
- * returns 1 on success, 0 on error
- */
+/* Set the nonce to be used for the recipNonce in the message created next */
 int ossl_cmp_ctx_set1_recipNonce(OSSL_CMP_CTX *ctx,
                                  const ASN1_OCTET_STRING *nonce)
 {
@@ -826,10 +760,7 @@ int ossl_cmp_ctx_set1_recipNonce(OSSL_CMP_CTX *ctx,
     return ossl_cmp_asn1_octet_string_set1(&ctx->recipNonce, nonce);
 }
 
-/*
- * Stores the given nonce as the last senderNonce sent out.
- * Returns 1 on success, 0 on error
- */
+/* Stores the given nonce as the last senderNonce sent out */
 int OSSL_CMP_CTX_set1_senderNonce(OSSL_CMP_CTX *ctx,
                                   const ASN1_OCTET_STRING *nonce)
 {
@@ -840,36 +771,16 @@ int OSSL_CMP_CTX_set1_senderNonce(OSSL_CMP_CTX *ctx,
     return ossl_cmp_asn1_octet_string_set1(&ctx->senderNonce, nonce);
 }
 
-/*
- * Set the host name of the (HTTP) proxy server to use for all connections
- * returns 1 on success, 0 on error
- */
-DEFINE_OSSL_CMP_CTX_set1(proxyName, char)
+/* Set the proxy server to use for HTTP(S) connections */
+DEFINE_OSSL_CMP_CTX_set1(proxy, char)
 
-/*
- * Set the (HTTP) host name of the CA server.
- * Returns 1 on success, 0 on error
- */
+/* Set the (HTTP) host name of the CMP server */
 DEFINE_OSSL_CMP_CTX_set1(serverName, char)
 
-/*
- * Sets the (HTTP) proxy port to be used.
- * Returns 1 on success, 0 on error
- */
-int OSSL_CMP_CTX_set_proxyPort(OSSL_CMP_CTX *ctx, int port)
-{
-    if (ctx == NULL) {
-        CMPerr(0, CMP_R_NULL_ARGUMENT);
-        return 0;
-    }
-    ctx->proxyPort = port;
-    return 1;
-}
+/* Set the server exclusion list of the HTTP proxy server */
+DEFINE_OSSL_CMP_CTX_set1(no_proxy, char)
 
-/*
- * sets the http connect/disconnect callback function to be used for HTTP(S)
- * returns 1 on success, 0 on error
- */
+/* Set the http connect/disconnect callback function to be used for HTTP(S) */
 int OSSL_CMP_CTX_set_http_cb(OSSL_CMP_CTX *ctx, OSSL_HTTP_bio_cb_t cb)
 {
     if (ctx == NULL) {
@@ -880,10 +791,7 @@ int OSSL_CMP_CTX_set_http_cb(OSSL_CMP_CTX *ctx, OSSL_HTTP_bio_cb_t cb)
     return 1;
 }
 
-/*
- * Set argument optionally to be used by the http connect/disconnect callback.
- * Returns 1 on success, 0 on error
- */
+/* Set argument optionally to be used by the http connect/disconnect callback */
 int OSSL_CMP_CTX_set_http_cb_arg(OSSL_CMP_CTX *ctx, void *arg)
 {
     if (ctx == NULL) {
@@ -907,10 +815,7 @@ void *OSSL_CMP_CTX_get_http_cb_arg(const OSSL_CMP_CTX *ctx)
     return ctx->http_cb_arg;
 }
 
-/*
- * Set callback function for sending CMP request and receiving response.
- * Returns 1 on success, 0 on error
- */
+/* Set callback function for sending CMP request and receiving response */
 int OSSL_CMP_CTX_set_transfer_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_transfer_cb_t cb)
 {
     if (ctx == NULL) {
@@ -921,10 +826,7 @@ int OSSL_CMP_CTX_set_transfer_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_transfer_cb_t cb)
     return 1;
 }
 
-/*
- * Set argument optionally to be used by the transfer callback.
- * Returns 1 on success, 0 on error
- */
+/* Set argument optionally to be used by the transfer callback */
 int OSSL_CMP_CTX_set_transfer_cb_arg(OSSL_CMP_CTX *ctx, void *arg)
 {
     if (ctx == NULL) {
@@ -948,10 +850,7 @@ void *OSSL_CMP_CTX_get_transfer_cb_arg(const OSSL_CMP_CTX *ctx)
     return ctx->transfer_cb_arg;
 }
 
-/*
- * Sets the (HTTP) server port to be used.
- * Returns 1 on success, 0 on error
- */
+/** Set the HTTP server port to be used */
 int OSSL_CMP_CTX_set_serverPort(OSSL_CMP_CTX *ctx, int port)
 {
     if (ctx == NULL) {
@@ -962,16 +861,10 @@ int OSSL_CMP_CTX_set_serverPort(OSSL_CMP_CTX *ctx, int port)
     return 1;
 }
 
-/*
- * Sets the HTTP path to be used on the server (e.g "pkix/").
- * Returns 1 on success, 0 on error
- */
+/* Set the HTTP path to be used on the server (e.g "pkix/") */
 DEFINE_OSSL_CMP_CTX_set1(serverPath, char)
 
-/*
- * Set the failInfo error code as bit encoding in OSSL_CMP_CTX.
- * Returns 1 on success, 0 on error
- */
+/* Set the failInfo error code as bit encoding in OSSL_CMP_CTX */
 int ossl_cmp_ctx_set_failInfoCode(OSSL_CMP_CTX *ctx, int fail_info)
 {
     if (!ossl_assert(ctx != NULL))
@@ -993,10 +886,7 @@ int OSSL_CMP_CTX_get_failInfoCode(const OSSL_CMP_CTX *ctx)
     return ctx->failInfoCode;
 }
 
-/*
- * Sets a Boolean or integer option of the context to the "val" arg.
- * Returns 1 on success, 0 on error
- */
+/* Set a Boolean or integer option of the context to the "val" arg */
 int OSSL_CMP_CTX_set_option(OSSL_CMP_CTX *ctx, int opt, int val)
 {
     int min_val;
diff --git a/crypto/cmp/cmp_http.c b/crypto/cmp/cmp_http.c
new file mode 100644
index 0000000000..be78d95577
--- /dev/null
+++ b/crypto/cmp/cmp_http.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2007-2019 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright Nokia 2007-2019
+ * Copyright Siemens AG 2015-2019
+ *
+ * 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
+ */
+
+#include <string.h>
+#include <stdio.h>
+
+#include <openssl/asn1t.h>
+#include <openssl/http.h>
+#include "internal/sockets.h"
+
+#include "openssl/cmp.h"
+#include "cmp_local.h"
+
+/* explicit #includes not strictly needed since implied by the above: */
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <openssl/bio.h>
+#include <openssl/buffer.h>
+#include <openssl/cmp.h>
+#include <openssl/err.h>
+
+/*
+ * Send the PKIMessage req and on success return the response, else NULL.
+ * Any previous error queue entries will likely be removed by ERR_clear_error().
+ */
+OSSL_CMP_MSG *OSSL_CMP_MSG_http_perform(OSSL_CMP_CTX *ctx,
+                                        const OSSL_CMP_MSG *req)
+{
+    char server_port[32];
+    STACK_OF(CONF_VALUE) *headers = NULL;
+    OSSL_CMP_MSG *res = NULL;
+    const char *const content_type_pkix = "application/pkixcmp";
+
+    if (ctx == NULL || req == NULL
+            || ctx->serverName == NULL || ctx->serverPort == 0) {
+        CMPerr(0, CMP_R_NULL_ARGUMENT);
+        return 0;
+    }
+
+    if (!X509V3_add_value("Pragma", "no-cache", &headers))
+        return NULL;
+
+    BIO_snprintf(server_port, sizeof(server_port), "%d", ctx->serverPort);
+
+    res = (OSSL_CMP_MSG *)
+        OSSL_HTTP_post_asn1(ctx->serverName, server_port, ctx->serverPath,
+                            OSSL_CMP_CTX_get_http_cb_arg(ctx) != NULL,
+                            ctx->proxy, ctx->no_proxy, NULL, NULL,
+                            ctx->http_cb, OSSL_CMP_CTX_get_http_cb_arg(ctx),
+                            headers, content_type_pkix,
+                            (ASN1_VALUE *)req, ASN1_ITEM_rptr(OSSL_CMP_MSG),
+                            0, 0, ctx->msg_timeout, content_type_pkix,
+                            ASN1_ITEM_rptr(OSSL_CMP_MSG));
+
+    sk_CONF_VALUE_pop_free(headers, X509V3_conf_free);
+    return res;
+}
diff --git a/crypto/cmp/cmp_local.h b/crypto/cmp/cmp_local.h
index 220e93e2ce..3017d1910b 100644
--- a/crypto/cmp/cmp_local.h
+++ b/crypto/cmp/cmp_local.h
@@ -38,8 +38,8 @@ struct ossl_cmp_ctx_st {
     char *serverPath;
     char *serverName;
     int serverPort;
-    char *proxyName;
-    int proxyPort;
+    char *proxy;
+    char *no_proxy;
     int msg_timeout; /* max seconds to wait for each CMP message round trip */
     int total_timeout; /* max number of seconds an enrollment may take, incl. */
     /* attempts polling for a response if a 'waiting' PKIStatus is received */