Add CURLOPT_CAINFO_PEM

CMakeLists.txt

@@ -702,6 +702,8 @@ set(CURL_CA_FALLBACK OFF CACHE BOOL
     "Set ON to use built-in CA store of TLS backend. Defaults to OFF")
 set(CURL_CA_PATH "auto" CACHE STRING
     "Location of default CA path. Set 'none' to disable or 'auto' for auto-detection. Defaults to 'auto'.")
+set(CURL_CA_BUNDLE_PEM OFF CACHE BOOL
+    "Set ON to use built-in CACERT_PEM from generated cacert.h. Defaults to OFF")
 
 if("${CURL_CA_BUNDLE}" STREQUAL "")
   message(FATAL_ERROR "Invalid value of CURL_CA_BUNDLE. Use 'none', 'auto' or file path.")

acinclude.m4

@@ -2306,6 +2306,24 @@ AC_HELP_STRING([--without-ca-fallback], [Don't use the built in CA store of the
     fi
     AC_DEFINE_UNQUOTED(CURL_CA_FALLBACK, 1, [define "1" to use built in CA store of SSL library ])
   fi
+
+  AC_MSG_CHECKING([whether to use built in CACERT_PEM from generated cacert.h])
+  AC_ARG_WITH(ca-built-in,
+AC_HELP_STRING([--with-ca-built-in], [Use the built in CACERT_PEM from generated cacert.h])
+AC_HELP_STRING([--without-ca-built-in], [Don't use the built in CACERT_PEM from generated cacert.h]),
+  [
+    if test "x$with_ca_built_in" != "xyes" -a "x$with_ca_built_in" != "xno"; then
+      AC_MSG_ERROR([--with-ca-built-in only allows yes or no as parameter])
+    fi
+  ],
+  [ with_ca_fallback="no"])
+  AC_MSG_RESULT([$with_ca_built_in])
+  if test "x$with_ca_built_in" = "xyes"; then
+    if test "x$OPENSSL_ENABLED" != "x1"; then
+      AC_MSG_ERROR([--with-ca-built-in only works with OpenSSL])
+    fi
+    AC_DEFINE_UNQUOTED(CURL_CA_BUNDLE_PEM, 1, [define "1" to use built in CACERT_PEM from generated cacert.h ])
+  fi
 ])
 
 dnl CURL_CHECK_WIN32_LARGEFILE

configure.ac

@@ -4982,6 +4982,7 @@ AC_MSG_NOTICE([Configured to build curl/libcurl:
   ca cert bundle:   ${ca}${ca_warning}
   ca cert path:     ${capath}${capath_warning}
   ca fallback:      ${with_ca_fallback}
+  ca built in:      ${with_ca_built_in}
   LDAP:             ${curl_ldap_msg}
   LDAPS:            ${curl_ldaps_msg}
   RTSP:             ${curl_rtsp_msg}

include/curl/curl.h

@@ -1954,6 +1954,14 @@ typedef enum {
   /* allow RCPT TO command to fail for some recipients */
   CURLOPT(CURLOPT_MAIL_RCPT_ALLLOWFAILS, CURLOPTTYPE_LONG, 290),
 
+  /* The CAfile in memory as PEM used to validate the proxy certificate
+     this option is used only if PROXY_SSL_VERIFYPEER is true */
+  CURLOPT(CURLOPT_CAINFO_PEM, CURLOPTTYPE_STRINGPOINT, 291),
+
+  /* The CAfile in memory as PEM used to validate the proxy certificate
+     this option is used only if PROXY_SSL_VERIFYPEER is true */
+  CURLOPT(CURLOPT_PROXY_CAINFO_PEM, CURLOPTTYPE_STRINGPOINT, 292),
+
   CURLOPT_LASTENTRY /* the last unused */
 } CURLoption;
 

lib/cacert.h

@@ -0,0 +1,38 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+/*
+
+regenerate this file like so:
+
+curl -Oz cacert.pem https://curl.haxx.se/ca/cacert.pem \
+&& xxd -i -C cacert.pem | sed -r 's/(0x..)$/\1, 0x00/' > lib/cacert.h
+
+unless CACERT_PEM is defined in here, there will be a compile error if
+CURL_CA_BUNDLE_PEM is defined, CACERT_PEM must be a proper null-terminated
+C string
+
+unsigned char CACERT_PEM[] = {
+  0x62, 0x6f, 0x62, 0x0a, 0x00
+};
+unsigned int CACERT_PEM_LEN = 4;
+*/

lib/setopt.c

@@ -1944,6 +1944,21 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option, va_list param)
       result = CURLE_NOT_BUILT_IN;
     break;
 #endif
+  case CURLOPT_CAINFO_PEM:
+    /*
+     * Set CA info for SSL connection. Specify entire PEM of the CA certificate
+     */
+    result = Curl_setstropt(&data->set.str[STRING_SSL_CAFILE_PEM_ORIG],
+                            va_arg(param, char *));
+    break;
+  case CURLOPT_PROXY_CAINFO_PEM:
+    /*
+     * Set CA info for SSL connection proxy.
+     * Specify entire PEM of the CA certificate
+     */
+    result = Curl_setstropt(&data->set.str[STRING_SSL_CAFILE_PEM_PROXY],
+                            va_arg(param, char *));
+    break;
   case CURLOPT_CRLFILE:
     /*
      * Set CRL file info for SSL connection. Specify file name of the CRL

lib/url.c

@@ -127,6 +127,10 @@ bool curl_win32_idn_to_ascii(const char *in, char **out);
 #include "curl_memory.h"
 #include "memdebug.h"
 
+#if defined(CURL_CA_BUNDLE_PEM)
+#include "cacert.h"
+#endif
+
 static void conn_free(struct connectdata *conn);
 static unsigned int get_protocol_family(unsigned int protocol);
 
@@ -507,6 +511,18 @@ CURLcode Curl_init_userdefined(struct Curl_easy *data)
   set->socks5_gssapi_nec = FALSE;
 #endif
 
+#if defined(CURL_CA_BUNDLE_PEM)
+  result = Curl_setstropt(&set->str[STRING_SSL_CAFILE_PEM_ORIG],
+                          (const char *) CACERT_PEM);
+  if(result)
+    return result;
+
+  result = Curl_setstropt(&set->str[STRING_SSL_CAFILE_PEM_PROXY],
+                          (const char *) CACERT_PEM);
+  if(result)
+    return result;
+#endif
+
   /* Set the default CA cert bundle/path detected/specified at build time.
    *
    * If Schannel is the selected SSL backend then these locations are
@@ -3555,6 +3571,10 @@ static CURLcode create_conn(struct Curl_easy *data,
   data->set.proxy_ssl.primary.CApath = data->set.str[STRING_SSL_CAPATH_PROXY];
   data->set.ssl.primary.CAfile = data->set.str[STRING_SSL_CAFILE_ORIG];
   data->set.proxy_ssl.primary.CAfile = data->set.str[STRING_SSL_CAFILE_PROXY];
+  data->set.ssl.primary.ca_file_pem =
+    data->set.str[STRING_SSL_CAFILE_PEM_ORIG];
+  data->set.proxy_ssl.primary.ca_file_pem =
+    data->set.str[STRING_SSL_CAFILE_PEM_PROXY];
   data->set.ssl.primary.random_file = data->set.str[STRING_SSL_RANDOM_FILE];
   data->set.proxy_ssl.primary.random_file =
     data->set.str[STRING_SSL_RANDOM_FILE];

lib/urldata.h

@@ -230,6 +230,7 @@ struct ssl_primary_config {
   char *cipher_list;     /* list of ciphers to use */
   char *cipher_list13;   /* list of TLS 1.3 cipher suites to use */
   char *pinned_key;
+  char *ca_file_pem;
   BIT(verifypeer);       /* set TRUE if this is desired */
   BIT(verifyhost);       /* set TRUE if CN/SAN must match hostname */
   BIT(verifystatus);     /* set TRUE if certificate status must be checked */
@@ -1529,6 +1530,8 @@ enum dupstring {
   STRING_SSL_CAPATH_PROXY, /* CA directory name (doesn't work on windows) */
   STRING_SSL_CAFILE_ORIG, /* certificate file to verify peer against */
   STRING_SSL_CAFILE_PROXY, /* certificate file to verify peer against */
+  STRING_SSL_CAFILE_PEM_ORIG, /* PEM certificate to verify peer against */
+  STRING_SSL_CAFILE_PEM_PROXY, /* PEM certificate to verify peer against */
   STRING_SSL_PINNEDPUBLICKEY_ORIG, /* public key file to verify peer against */
   STRING_SSL_PINNEDPUBLICKEY_PROXY, /* public key file to verify proxy */
   STRING_SSL_CIPHER_LIST_ORIG, /* list of ciphers to use */

lib/vtls/openssl.c

@@ -2385,6 +2385,61 @@ static int ossl_new_session_cb(SSL *ssl, SSL_SESSION *ssl_sessionid)
   return res;
 }
 
+static CURLcode load_cacert_from_memory(SSL_CTX *ctx,
+                                        const char * const ca_file_pem)
+{
+  /* these need freed at the end */
+  BIO *cbio = NULL;
+  STACK_OF(X509_INFO) *inf = NULL;
+
+  /* everything else is just a reference */
+  int i, count = 0;
+  X509_STORE *cts = NULL;
+  X509_INFO *itmp = NULL;
+
+  CURLcode result = CURLE_SSL_CACERT_BADFILE;
+
+  do {
+    /* casting strlen to int feels wrong, but what to do with this API? */
+    cbio = BIO_new_mem_buf(ca_file_pem, (int) strlen(ca_file_pem));
+    if(!cbio)
+      break;
+
+    cts = SSL_CTX_get_cert_store(ctx);
+    if(!cts)
+      break;
+
+    inf = PEM_X509_INFO_read_bio(cbio, NULL, NULL, NULL);
+    if(!inf)
+      break;
+
+    /* add each entry from PEM file to x509_store */
+    for(i = 0; i < sk_X509_INFO_num(inf); ++i) {
+      itmp = sk_X509_INFO_value(inf, i);
+      if(itmp->x509) {
+        X509_STORE_add_cert(cts, itmp->x509);
+        ++count;
+      }
+      if(itmp->crl) {
+        X509_STORE_add_crl(cts, itmp->crl);
+        ++count;
+      }
+    }
+
+    /* if we didn't end up importing anything, treat that as an error */
+    if(count > 0)
+      result = CURLE_OK;
+  } while(0);
+
+  if(inf)
+    sk_X509_INFO_pop_free(inf, X509_INFO_free);
+
+  if(cbio)
+    BIO_free(cbio);
+
+  return result;
+}
+
 static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
 {
   CURLcode result = CURLE_OK;
@@ -2416,6 +2471,7 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
   const char * const ssl_cert_type = SSL_SET_OPTION(cert_type);
   const char * const ssl_cafile = SSL_CONN_CONFIG(CAfile);
   const char * const ssl_capath = SSL_CONN_CONFIG(CApath);
+  const char * const ca_file_pem = SSL_CONN_CONFIG(ca_file_pem);
   const bool verifypeer = SSL_CONN_CONFIG(verifypeer);
   const char * const ssl_crlfile = SSL_SET_OPTION(CRLfile);
   char error_buffer[256];
@@ -2720,6 +2776,16 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
   }
 #endif
 
+  if(ca_file_pem && load_cacert_from_memory(backend->ctx, ca_file_pem)) {
+    if(verifypeer) {
+      /* Fail if we insist on successfully verifying the server. */
+      failf(data, "error setting certificate from memory");
+      return CURLE_SSL_CACERT_BADFILE;
+    }
+    /* Continue with a warning if no certificate verification is required. */
+    infof(data, "error setting certificate file, continuing anyway\n");
+  }
+
 #if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)
   /* OpenSSL 3.0.0 has deprecated SSL_CTX_load_verify_locations */
   if(ssl_cafile) {

lib/vtls/vtls.c

@@ -93,6 +93,7 @@ Curl_ssl_config_matches(struct ssl_primary_config* data,
      (data->verifystatus == needle->verifystatus) &&
      Curl_safe_strcasecompare(data->CApath, needle->CApath) &&
      Curl_safe_strcasecompare(data->CAfile, needle->CAfile) &&
+     Curl_safe_strcasecompare(data->ca_file_pem, needle->ca_file_pem) &&
      Curl_safe_strcasecompare(data->clientcert, needle->clientcert) &&
      Curl_safe_strcasecompare(data->random_file, needle->random_file) &&
      Curl_safe_strcasecompare(data->egdsocket, needle->egdsocket) &&
@@ -117,6 +118,7 @@ Curl_clone_primary_ssl_config(struct ssl_primary_config *source,
 
   CLONE_STRING(CApath);
   CLONE_STRING(CAfile);
+  CLONE_STRING(ca_file_pem);
   CLONE_STRING(clientcert);
   CLONE_STRING(random_file);
   CLONE_STRING(egdsocket);
@@ -131,6 +133,7 @@ void Curl_free_primary_ssl_config(struct ssl_primary_config* sslc)
 {
   Curl_safefree(sslc->CApath);
   Curl_safefree(sslc->CAfile);
+  Curl_safefree(sslc->ca_file_pem);
   Curl_safefree(sslc->clientcert);
   Curl_safefree(sslc->random_file);
   Curl_safefree(sslc->egdsocket);