From: Stefan Eissing <stefan@eissing.org>
Date: Thu, 5 Jan 2023 16:01:42 +0000 (+0100)
Subject: ngtcp2: add CURLOPT_SSL_CTX_FUNCTION support for openssl+wolfssl
X-Git-Tag: curl-7_88_0~144
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=088c08a7e474bda43c5fa336cf30ad24b87097b2;p=thirdparty%2Fcurl.git

ngtcp2: add CURLOPT_SSL_CTX_FUNCTION support for openssl+wolfssl

Using common method for SSL_CTX initialization of verfiy peer and CA
settings. This also provides X509_STORE sharing to become available for
ngtcp2+openssl HTTP/3.

Reported-by: violetlige on github

Fixes #10222
Closes #10239
---

diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index 291255e794..4f6fe5593d 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -295,20 +295,27 @@ static void keylog_callback(const WOLFSSL *ssl, const char *line)
 static int init_ngh3_conn(struct Curl_cfilter *cf);
 
 #ifdef USE_OPENSSL
-static SSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf, struct Curl_easy *data)
+static CURLcode quic_ssl_ctx(SSL_CTX **pssl_ctx,
+                             struct Curl_cfilter *cf, struct Curl_easy *data)
 {
   struct connectdata *conn = cf->conn;
+  CURLcode result = CURLE_FAILED_INIT;
   SSL_CTX *ssl_ctx = SSL_CTX_new(TLS_method());
 
+  if(!ssl_ctx) {
+    result = CURLE_OUT_OF_MEMORY;
+    goto out;
+  }
+
 #ifdef OPENSSL_IS_BORINGSSL
   if(ngtcp2_crypto_boringssl_configure_client_context(ssl_ctx) != 0) {
     failf(data, "ngtcp2_crypto_boringssl_configure_client_context failed");
-    return NULL;
+    goto out;
   }
 #else
   if(ngtcp2_crypto_openssl_configure_client_context(ssl_ctx) != 0) {
     failf(data, "ngtcp2_crypto_openssl_configure_client_context failed");
-    return NULL;
+    goto out;
   }
 #endif
 
@@ -317,19 +324,19 @@ static SSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf, struct Curl_easy *data)
 #ifdef OPENSSL_IS_BORINGSSL
   if(SSL_CTX_set1_curves_list(ssl_ctx, QUIC_GROUPS) != 1) {
     failf(data, "SSL_CTX_set1_curves_list failed");
-    return NULL;
+    goto out;
   }
 #else
   if(SSL_CTX_set_ciphersuites(ssl_ctx, QUIC_CIPHERS) != 1) {
     char error_buffer[256];
     ERR_error_string_n(ERR_get_error(), error_buffer, sizeof(error_buffer));
     failf(data, "SSL_CTX_set_ciphersuites: %s", error_buffer);
-    return NULL;
+    goto out;
   }
 
   if(SSL_CTX_set1_groups_list(ssl_ctx, QUIC_GROUPS) != 1) {
     failf(data, "SSL_CTX_set1_groups_list failed");
-    return NULL;
+    goto out;
   }
 #endif
 
@@ -339,34 +346,35 @@ static SSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf, struct Curl_easy *data)
     SSL_CTX_set_keylog_callback(ssl_ctx, keylog_callback);
   }
 
-  if(conn->ssl_config.verifypeer) {
-    const char * const ssl_cafile = conn->ssl_config.CAfile;
-    const char * const ssl_capath = conn->ssl_config.CApath;
+  result = Curl_ssl_setup_x509_store(cf, data, ssl_ctx);
+  if(result)
+    goto out;
 
-    if(ssl_cafile || ssl_capath) {
-      SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);
-      /* tell OpenSSL where to find CA certificates that are used to verify
-         the server's certificate. */
-      if(!SSL_CTX_load_verify_locations(ssl_ctx, ssl_cafile, ssl_capath)) {
-        /* Fail if we insist on successfully verifying the server. */
-        failf(data, "error setting certificate verify locations:"
-              "  CAfile: %s CApath: %s",
-              ssl_cafile ? ssl_cafile : "none",
-              ssl_capath ? ssl_capath : "none");
-        return NULL;
-      }
-      infof(data, " CAfile: %s", ssl_cafile ? ssl_cafile : "none");
-      infof(data, " CApath: %s", ssl_capath ? ssl_capath : "none");
-    }
-#ifdef CURL_CA_FALLBACK
-    else {
-      /* verifying the peer without any CA certificates won't work so
-         use openssl's built-in default as fallback */
-      SSL_CTX_set_default_verify_paths(ssl_ctx);
+  /* OpenSSL always tries to verify the peer, this only says whether it should
+   * fail to connect if the verification fails, or if it should continue
+   * anyway. In the latter case the result of the verification is checked with
+   * SSL_get_verify_result() below. */
+  SSL_CTX_set_verify(ssl_ctx, conn->ssl_config.verifypeer ?
+                     SSL_VERIFY_PEER : SSL_VERIFY_NONE, NULL);
+
+  /* give application a chance to interfere with SSL set up. */
+  if(data->set.ssl.fsslctx) {
+    Curl_set_in_callback(data, true);
+    result = (*data->set.ssl.fsslctx)(data, ssl_ctx,
+                                      data->set.ssl.fsslctxp);
+    Curl_set_in_callback(data, false);
+    if(result) {
+      failf(data, "error signaled by ssl ctx callback");
+      goto out;
     }
-#endif
   }
-  return ssl_ctx;
+  result = CURLE_OK;
+
+out:
+  *pssl_ctx = result? NULL : ssl_ctx;
+  if(result && ssl_ctx)
+    SSL_CTX_free(ssl_ctx);
+  return result;
 }
 
 static CURLcode quic_set_client_cert(struct Curl_cfilter *cf,
@@ -472,15 +480,21 @@ static CURLcode quic_init_ssl(struct Curl_cfilter *cf,
 }
 #elif defined(USE_WOLFSSL)
 
-static WOLFSSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf,
-                                 struct Curl_easy *data)
+static CURLcode quic_ssl_ctx(WOLFSSL_CTX **pssl_ctx,
+                             struct Curl_cfilter *cf, struct Curl_easy *data)
 {
   struct connectdata *conn = cf->conn;
+  CURLcode result = CURLE_FAILED_INIT;
   WOLFSSL_CTX *ssl_ctx = wolfSSL_CTX_new(wolfTLSv1_3_client_method());
 
+  if(!ssl_ctx) {
+    result = CURLE_OUT_OF_MEMORY;
+    goto out;
+  }
+
   if(ngtcp2_crypto_wolfssl_configure_client_context(ssl_ctx) != 0) {
     failf(data, "ngtcp2_crypto_wolfssl_configure_client_context failed");
-    return NULL;
+    goto out;
   }
 
   wolfSSL_CTX_set_default_verify_paths(ssl_ctx);
@@ -489,12 +503,12 @@ static WOLFSSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf,
     char error_buffer[256];
     ERR_error_string_n(ERR_get_error(), error_buffer, sizeof(error_buffer));
     failf(data, "SSL_CTX_set_ciphersuites: %s", error_buffer);
-    return NULL;
+    goto out;
   }
 
   if(wolfSSL_CTX_set1_groups_list(ssl_ctx, (char *)QUIC_GROUPS) != 1) {
     failf(data, "SSL_CTX_set1_groups_list failed");
-    return NULL;
+    goto out;
   }
 
   /* Open the file if a TLS or QUIC backend has not done this before. */
@@ -504,7 +518,7 @@ static WOLFSSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf,
     wolfSSL_CTX_set_keylog_callback(ssl_ctx, keylog_callback);
 #else
     failf(data, "wolfSSL was built without keylog callback");
-    return NULL;
+    goto out;
 #endif
   }
 
@@ -512,8 +526,8 @@ static WOLFSSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf,
     const char * const ssl_cafile = conn->ssl_config.CAfile;
     const char * const ssl_capath = conn->ssl_config.CApath;
 
-    if(ssl_cafile || ssl_capath) {
-      wolfSSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);
+    wolfSSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);
+    if(conn->ssl_config.CAfile || conn->ssl_config.CApath) {
       /* tell wolfSSL where to find CA certificates that are used to verify
          the server's certificate. */
       if(!wolfSSL_CTX_load_verify_locations(ssl_ctx, ssl_cafile, ssl_capath)) {
@@ -522,7 +536,7 @@ static WOLFSSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf,
               "  CAfile: %s CApath: %s",
               ssl_cafile ? ssl_cafile : "none",
               ssl_capath ? ssl_capath : "none");
-        return NULL;
+        goto out;
       }
       infof(data, " CAfile: %s", ssl_cafile ? ssl_cafile : "none");
       infof(data, " CApath: %s", ssl_capath ? ssl_capath : "none");
@@ -539,7 +553,24 @@ static WOLFSSL_CTX *quic_ssl_ctx(struct Curl_cfilter *cf,
     wolfSSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_NONE, NULL);
   }
 
-  return ssl_ctx;
+  /* give application a chance to interfere with SSL set up. */
+  if(data->set.ssl.fsslctx) {
+    Curl_set_in_callback(data, true);
+    result = (*data->set.ssl.fsslctx)(data, ssl_ctx,
+                                      data->set.ssl.fsslctxp);
+    Curl_set_in_callback(data, false);
+    if(result) {
+      failf(data, "error signaled by ssl ctx callback");
+      goto out;
+    }
+  }
+  result = CURLE_OK;
+
+out:
+  *pssl_ctx = result? NULL : ssl_ctx;
+  if(result && ssl_ctx)
+    SSL_CTX_free(ssl_ctx);
+  return result;
 }
 
 /** SSL callbacks ***/
@@ -2217,17 +2248,17 @@ static CURLcode cf_connect_start(struct Curl_cfilter *cf,
 
   ctx->version = NGTCP2_PROTO_VER_MAX;
 #ifdef USE_OPENSSL
-  ctx->sslctx = quic_ssl_ctx(cf, data);
-  if(!ctx->sslctx)
-    return CURLE_QUIC_CONNECT_ERROR;
+  result = quic_ssl_ctx(&ctx->sslctx, cf, data);
+  if(result)
+    return result;
 
   result = quic_set_client_cert(cf, data);
   if(result)
     return result;
 #elif defined(USE_WOLFSSL)
-  ctx->sslctx = quic_ssl_ctx(cf, data);
-  if(!ctx->sslctx)
-    return CURLE_QUIC_CONNECT_ERROR;
+  result = quic_ssl_ctx(&ctx->sslctx, cf, data);
+  if(result)
+    return result;
 #endif
 
   result = quic_init_ssl(cf, data);
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 6e0f1bd2ad..7abcfc0b40 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -3398,9 +3398,9 @@ static void set_cached_x509_store(struct Curl_cfilter *cf,
   }
 }
 
-static CURLcode set_up_x509_store(struct Curl_cfilter *cf,
-                                  struct Curl_easy *data,
-                                  struct ssl_backend_data *backend)
+CURLcode Curl_ssl_setup_x509_store(struct Curl_cfilter *cf,
+                                   struct Curl_easy *data,
+                                   SSL_CTX *ssl_ctx)
 {
   struct ssl_primary_config *conn_config = Curl_ssl_cf_get_primary_config(cf);
   struct ssl_config_data *ssl_config = Curl_ssl_cf_get_config(cf, data);
@@ -3420,10 +3420,10 @@ static CURLcode set_up_x509_store(struct Curl_cfilter *cf,
 
   cached_store = get_cached_x509_store(cf, data);
   if(cached_store && cache_criteria_met && X509_STORE_up_ref(cached_store)) {
-    SSL_CTX_set_cert_store(backend->ctx, cached_store);
+    SSL_CTX_set_cert_store(ssl_ctx, cached_store);
   }
   else {
-    X509_STORE *store = SSL_CTX_get_cert_store(backend->ctx);
+    X509_STORE *store = SSL_CTX_get_cert_store(ssl_ctx);
 
     result = populate_x509_store(cf, data, store);
     if(result == CURLE_OK && cache_criteria_met) {
@@ -3434,11 +3434,11 @@ static CURLcode set_up_x509_store(struct Curl_cfilter *cf,
   return result;
 }
 #else /* HAVE_SSL_X509_STORE_SHARE */
-static CURLcode set_up_x509_store(struct Curl_cfilter *cf,
-                                  struct Curl_easy *data,
-                                  struct ssl_backend_data *backend)
+CURLcode Curl_ssl_setup_x509_store(struct Curl_cfilter *cf,
+                                   struct Curl_easy *data,
+                                   SSL_CTX *ssl_ctx)
 {
-  X509_STORE *store = SSL_CTX_get_cert_store(backend->ctx);
+  X509_STORE *store = SSL_CTX_get_cert_store(ssl_ctx);
 
   return populate_x509_store(cf, data, store);
 }
@@ -3753,7 +3753,7 @@ static CURLcode ossl_connect_step1(struct Curl_cfilter *cf,
   }
 #endif
 
-  result = set_up_x509_store(cf, data, backend);
+  result = Curl_ssl_setup_x509_store(cf, data, backend->ctx);
   if(result)
     return result;
 
diff --git a/lib/vtls/openssl.h b/lib/vtls/openssl.h
index 1e9701b515..950faab889 100644
--- a/lib/vtls/openssl.h
+++ b/lib/vtls/openssl.h
@@ -56,5 +56,14 @@ CURLcode Curl_ossl_set_client_cert(struct Curl_easy *data,
 
 CURLcode Curl_ossl_certchain(struct Curl_easy *data, SSL *ssl);
 
+/**
+ * Setup the OpenSSL X509_STORE in `ssl_ctx` for the cfilter `cf` and
+ * easy handle `data`. Will allow reuse of a shared cache if suitable
+ * and configured.
+ */
+CURLcode Curl_ssl_setup_x509_store(struct Curl_cfilter *cf,
+                                   struct Curl_easy *data,
+                                   SSL_CTX *ssl_ctx);
+
 #endif /* USE_OPENSSL */
 #endif /* HEADER_CURL_SSLUSE_H */