crypto: add cert.fingerprint256 as SHA256 fingerprint

PR-URL: #17690
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: bjori

src/env.h

@@ -151,6 +151,7 @@ class ModuleWrap;
   V(fd_string, "fd")                                                          \
   V(file_string, "file")                                                      \
   V(fingerprint_string, "fingerprint")                                        \
+  V(fingerprint256_string, "fingerprint256")                                  \
   V(flags_string, "flags")                                                    \
   V(get_data_clone_error_string, "_getDataCloneError")                        \
   V(get_shared_array_buffer_id_string, "_getSharedArrayBufferId")             \

src/node_crypto.cc

@@ -1812,6 +1812,25 @@ static bool SafeX509ExtPrint(BIO* out, X509_EXTENSION* ext) {
 }
 
 
+static void AddFingerprintDigest(const unsigned char* md,
+                                 unsigned int md_size,
+                                 char (*fingerprint)[3 * EVP_MAX_MD_SIZE + 1]) {
+  unsigned int i;
+  const char hex[] = "0123456789ABCDEF";
+
+  for (i = 0; i < md_size; i++) {
+    (*fingerprint)[3*i] = hex[(md[i] & 0xf0) >> 4];
+    (*fingerprint)[(3*i)+1] = hex[(md[i] & 0x0f)];
+    (*fingerprint)[(3*i)+2] = ':';
+  }
+
+  if (md_size > 0) {
+    (*fingerprint)[(3*(md_size-1))+2] = '\0';
+  } else {
+    (*fingerprint)[0] = '\0';
+  }
+}
+
 static Local<Object> X509ToObject(Environment* env, X509* cert) {
   EscapableHandleScope scope(env->isolate());
   Local<Context> context = env->context();
@@ -1928,26 +1947,18 @@ static Local<Object> X509ToObject(Environment* env, X509* cert) {
                                 mem->length)).FromJust();
   BIO_free_all(bio);
 
-  unsigned int md_size, i;
   unsigned char md[EVP_MAX_MD_SIZE];
+  unsigned int md_size;
+  char fingerprint[EVP_MAX_MD_SIZE * 3 + 1];
   if (X509_digest(cert, EVP_sha1(), md, &md_size)) {
-    const char hex[] = "0123456789ABCDEF";
-    char fingerprint[EVP_MAX_MD_SIZE * 3];
-
-    for (i = 0; i < md_size; i++) {
-      fingerprint[3*i] = hex[(md[i] & 0xf0) >> 4];
-      fingerprint[(3*i)+1] = hex[(md[i] & 0x0f)];
-      fingerprint[(3*i)+2] = ':';
-    }
-
-    if (md_size > 0) {
-      fingerprint[(3*(md_size-1))+2] = '\0';
-    } else {
-      fingerprint[0] = '\0';
-    }
-
-    info->Set(context, env->fingerprint_string(),
-              OneByteString(env->isolate(), fingerprint)).FromJust();
+      AddFingerprintDigest(md, md_size, &fingerprint);
+      info->Set(context, env->fingerprint_string(),
+                OneByteString(env->isolate(), fingerprint)).FromJust();
+  }
+  if (X509_digest(cert, EVP_sha256(), md, &md_size)) {
+      AddFingerprintDigest(md, md_size, &fingerprint);
+      info->Set(context, env->fingerprint256_string(),
+                OneByteString(env->isolate(), fingerprint)).FromJust();
   }
 
   STACK_OF(ASN1_OBJECT)* eku = static_cast<STACK_OF(ASN1_OBJECT)*>(