vtls: compare cert blob when finding a connection to reuse

Reported-by: Gergely Nagy
Fixes #5617
Closes #5619

lib/url.c

@@ -3609,6 +3609,7 @@ static CURLcode create_conn(struct Curl_easy *data,
     data->set.str[STRING_SSL_CIPHER13_LIST_ORIG];
   data->set.ssl.primary.pinned_key =
     data->set.str[STRING_SSL_PINNEDPUBLICKEY_ORIG];
+  data->set.ssl.primary.cert_blob = data->set.blobs[BLOB_CERT_ORIG];
 
 #ifndef CURL_DISABLE_PROXY
   data->set.proxy_ssl.primary.CApath = data->set.str[STRING_SSL_CAPATH_PROXY];
@@ -3622,6 +3623,7 @@ static CURLcode create_conn(struct Curl_easy *data,
     data->set.str[STRING_SSL_CIPHER13_LIST_PROXY];
   data->set.proxy_ssl.primary.pinned_key =
     data->set.str[STRING_SSL_PINNEDPUBLICKEY_PROXY];
+  data->set.proxy_ssl.primary.cert_blob = data->set.blobs[BLOB_CERT_PROXY];
   data->set.proxy_ssl.CRLfile = data->set.str[STRING_SSL_CRLFILE_PROXY];
   data->set.proxy_ssl.issuercert = data->set.str[STRING_SSL_ISSUERCERT_PROXY];
   data->set.proxy_ssl.cert = data->set.str[STRING_CERT_PROXY];
@@ -3655,7 +3657,7 @@ static CURLcode create_conn(struct Curl_easy *data,
   data->set.ssl.issuercert_blob = data->set.blobs[BLOB_SSL_ISSUERCERT_ORIG];
 
   if(!Curl_clone_primary_ssl_config(&data->set.ssl.primary,
-     &conn->ssl_config)) {
+                                    &conn->ssl_config)) {
     result = CURLE_OUT_OF_MEMORY;
     goto out;
   }

lib/urldata.h

@@ -229,6 +229,7 @@ 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;
+  struct curl_blob *cert_blob;
   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 */

lib/vtls/vtls.c

@@ -63,6 +63,7 @@
 #include "warnless.h"
 #include "curl_base64.h"
 #include "curl_printf.h"
+#include "strdup.h"
 
 /* The last #include files should be: */
 #include "curl_memory.h"
@@ -82,6 +83,44 @@
   else                                       \
     dest->var = NULL;
 
+#define CLONE_BLOB(var)                         \
+  if(blobdup(&dest->var, source->var))         \
+    return FALSE;
+
+static CURLcode blobdup(struct curl_blob **dest,
+                        struct curl_blob *src)
+{
+  DEBUGASSERT(dest);
+  DEBUGASSERT(!*dest);
+  if(src) {
+    /* only if there's data to dupe! */
+    struct curl_blob *d;
+    d = malloc(sizeof(struct curl_blob) + src->len);
+    if(!d)
+      return CURLE_OUT_OF_MEMORY;
+    d->len = src->len;
+    /* Always duplicate because the connection may survive longer than the
+       handle that passed in the blob. */
+    d->flags = CURL_BLOB_COPY;
+    d->data = (void *)((char *)d + sizeof(struct curl_blob));
+    memcpy(d->data, src->data, src->len);
+    *dest = d;
+  }
+  return CURLE_OK;
+}
+
+/* returns TRUE if the blobs are identical */
+static bool blobcmp(struct curl_blob *first, struct curl_blob *second)
+{
+  if(!first && !second) /* both are NULL */
+    return TRUE;
+  if(!first || !second) /* one is NULL */
+    return FALSE;
+  if(first->len != second->len) /* different sizes */
+    return FALSE;
+  return !memcmp(first->data, second->data, first->len); /* same data */
+}
+
 bool
 Curl_ssl_config_matches(struct ssl_primary_config *data,
                         struct ssl_primary_config *needle)
@@ -91,6 +130,7 @@ Curl_ssl_config_matches(struct ssl_primary_config *data,
      (data->verifypeer == needle->verifypeer) &&
      (data->verifyhost == needle->verifyhost) &&
      (data->verifystatus == needle->verifystatus) &&
+     blobcmp(data->cert_blob, needle->cert_blob) &&
      Curl_safe_strcasecompare(data->CApath, needle->CApath) &&
      Curl_safe_strcasecompare(data->CAfile, needle->CAfile) &&
      Curl_safe_strcasecompare(data->clientcert, needle->clientcert) &&
@@ -115,6 +155,7 @@ Curl_clone_primary_ssl_config(struct ssl_primary_config *source,
   dest->verifystatus = source->verifystatus;
   dest->sessionid = source->sessionid;
 
+  CLONE_BLOB(cert_blob);
   CLONE_STRING(CApath);
   CLONE_STRING(CAfile);
   CLONE_STRING(clientcert);
@@ -137,6 +178,7 @@ void Curl_free_primary_ssl_config(struct ssl_primary_config *sslc)
   Curl_safefree(sslc->cipher_list);
   Curl_safefree(sslc->cipher_list13);
   Curl_safefree(sslc->pinned_key);
+  Curl_safefree(sslc->cert_blob);
 }
 
 #ifdef USE_SSL