openssl: change FILE ops to BIO ops

To make builds with VS2015 work. Recent changes in VS2015 _IOB_ENTRIES
handling is causing problems. This fix changes the OpenSSL backend code
to use BIO functions instead of FILE I/O functions to circumvent those
problems.

Closes #2512

1 files changed, 41 insertions, 15 deletions

diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index f6d647e1e..f6a4bd3fb 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -661,18 +661,28 @@ int cert_stuff(struct connectdata *conn,
 
     case SSL_FILETYPE_PKCS12:
     {
-      FILE *f;
-      PKCS12 *p12;
+      BIO *fp = NULL;
+      PKCS12 *p12 = NULL;
       EVP_PKEY *pri;
       STACK_OF(X509) *ca = NULL;
 
-      f = fopen(cert_file, "rb");
-      if(!f) {
+      fp = BIO_new(BIO_s_file());
+      if(fp == NULL) {
+        failf(data,
+              "BIO_new return NULL, " OSSL_PACKAGE
+              " error %s",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        return 0;
+      }
+
+      if(BIO_read_filename(fp, cert_file) <= 0) {
         failf(data, "could not open PKCS12 file '%s'", cert_file);
+        BIO_free(fp);
         return 0;
       }
-      p12 = d2i_PKCS12_fp(f, NULL);
-      fclose(f);
+      p12 = d2i_PKCS12_bio(fp, NULL);
+      BIO_free(fp);
 
       if(!p12) {
         failf(data, "error reading PKCS12 file '%s'", cert_file);
@@ -3127,7 +3137,8 @@ static CURLcode servercert(struct connectdata *conn,
   long lerr, len;
   struct Curl_easy *data = conn->data;
   X509 *issuer;
-  FILE *fp;
+  BIO *fp = NULL;
+  char error_buffer[256]="";
   char buffer[2048];
   const char *ptr;
   long * const certverifyresult = SSL_IS_PROXY() ?
@@ -3138,8 +3149,20 @@ static CURLcode servercert(struct connectdata *conn,
     /* we've been asked to gather certificate info! */
     (void)get_cert_chain(conn, connssl);
 
+  fp = BIO_new(BIO_s_file());
+  if(fp == NULL) {
+    failf(data,
+          "BIO_new return NULL, " OSSL_PACKAGE
+          " error %s",
+          ossl_strerror(ERR_get_error(), error_buffer,
+                        sizeof(error_buffer)) );
+    BIO_free(mem);
+    return 0;
+  }
+
   BACKEND->server_cert = SSL_get_peer_certificate(BACKEND->handle);
   if(!BACKEND->server_cert) {
+    BIO_free(fp);
     BIO_free(mem);
     if(!strict)
       return CURLE_OK;
@@ -3169,6 +3192,7 @@ static CURLcode servercert(struct connectdata *conn,
   if(SSL_CONN_CONFIG(verifyhost)) {
     result = verifyhost(conn, BACKEND->server_cert);
     if(result) {
+      BIO_free(fp);
       X509_free(BACKEND->server_cert);
       BACKEND->server_cert = NULL;
       return result;
@@ -3190,35 +3214,35 @@ static CURLcode servercert(struct connectdata *conn,
 
     /* e.g. match issuer name with provided issuer certificate */
     if(SSL_SET_OPTION(issuercert)) {
-      fp = fopen(SSL_SET_OPTION(issuercert), FOPEN_READTEXT);
-      if(!fp) {
+      if(BIO_read_filename(fp, SSL_SET_OPTION(issuercert)) <= 0) {
         if(strict)
           failf(data, "SSL: Unable to open issuer cert (%s)",
                 SSL_SET_OPTION(issuercert));
+        BIO_free(fp);
         X509_free(BACKEND->server_cert);
         BACKEND->server_cert = NULL;
         return CURLE_SSL_ISSUER_ERROR;
       }
 
-      issuer = PEM_read_X509(fp, NULL, ZERO_NULL, NULL);
+      issuer = PEM_read_bio_X509(fp, NULL, ZERO_NULL, NULL);
       if(!issuer) {
         if(strict)
           failf(data, "SSL: Unable to read issuer cert (%s)",
                 SSL_SET_OPTION(issuercert));
-        X509_free(BACKEND->server_cert);
+        BIO_free(fp);
         X509_free(issuer);
-        fclose(fp);
+        X509_free(BACKEND->server_cert);
+        BACKEND->server_cert = NULL;
         return CURLE_SSL_ISSUER_ERROR;
       }
 
-      fclose(fp);
-
       if(X509_check_issued(issuer, BACKEND->server_cert) != X509_V_OK) {
         if(strict)
           failf(data, "SSL: Certificate issuer check failed (%s)",
                 SSL_SET_OPTION(issuercert));
-        X509_free(BACKEND->server_cert);
+        BIO_free(fp);
         X509_free(issuer);
+        X509_free(BACKEND->server_cert);
         BACKEND->server_cert = NULL;
         return CURLE_SSL_ISSUER_ERROR;
       }
@@ -3253,6 +3277,7 @@ static CURLcode servercert(struct connectdata *conn,
   if(SSL_CONN_CONFIG(verifystatus)) {
     result = verifystatus(conn, connssl);
     if(result) {
+      BIO_free(fp);
       X509_free(BACKEND->server_cert);
       BACKEND->server_cert = NULL;
       return result;
@@ -3272,6 +3297,7 @@ static CURLcode servercert(struct connectdata *conn,
       failf(data, "SSL: public key does not match pinned public key!");
   }
 
+  BIO_free(fp);
   X509_free(BACKEND->server_cert);
   BACKEND->server_cert = NULL;
   connssl->connecting_state = ssl_connect_done;