From 7008afd40ef604e6455b9615f1d81f95d00886fd Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Tue, 31 Oct 2017 21:28:16 +0900
Subject: [PATCH] nghttpx: Refactor get_x509_fingerprint to accept hash
 function

---
 src/shrpx_log.cc              |  3 ++-
 src/shrpx_mruby_module_env.cc |  3 ++-
 src/shrpx_tls.cc              |  6 +++---
 src/shrpx_tls.h               | 10 ++++++----
 4 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/shrpx_log.cc b/src/shrpx_log.cc
index c803378c..7c27236f 100644
--- a/src/shrpx_log.cc
+++ b/src/shrpx_log.cc
@@ -544,7 +544,8 @@ void upstream_accesslog(const std::vector<LogFragment> &lfv,
         break;
       }
       std::array<uint8_t, 32> buf;
-      auto len = tls::get_x509_fingerprint(buf.data(), buf.size(), x);
+      auto len =
+          tls::get_x509_fingerprint(buf.data(), buf.size(), x, EVP_sha256());
       X509_free(x);
       if (len <= 0) {
         std::tie(p, last) = copy('-', p, last);
diff --git a/src/shrpx_mruby_module_env.cc b/src/shrpx_mruby_module_env.cc
index 5a7b9469..5729e1c7 100644
--- a/src/shrpx_mruby_module_env.cc
+++ b/src/shrpx_mruby_module_env.cc
@@ -160,7 +160,8 @@ mrb_value env_get_tls_client_fingerprint(mrb_state *mrb, mrb_value self) {
 
   // Fingerprint is SHA-256, so we need 32 bytes buffer.
   std::array<uint8_t, 32> buf;
-  auto slen = tls::get_x509_fingerprint(buf.data(), buf.size(), x);
+  auto slen =
+      tls::get_x509_fingerprint(buf.data(), buf.size(), x, EVP_sha256());
   X509_free(x);
   if (slen == -1) {
     mrb_raise(mrb, E_RUNTIME_ERROR, "could not compute client fingerprint");
diff --git a/src/shrpx_tls.cc b/src/shrpx_tls.cc
index 806ae103..8126b5ce 100644
--- a/src/shrpx_tls.cc
+++ b/src/shrpx_tls.cc
@@ -1920,10 +1920,10 @@ int verify_ocsp_response(SSL_CTX *ssl_ctx, const uint8_t *ocsp_resp,
   return 0;
 }
 
-ssize_t get_x509_fingerprint(uint8_t *dst, size_t dstlen, X509 *x) {
-  assert(dstlen >= 32);
+ssize_t get_x509_fingerprint(uint8_t *dst, size_t dstlen, const X509 *x,
+                             const EVP_MD *md) {
   unsigned int len = dstlen;
-  if (X509_digest(x, EVP_sha256(), dst, &len) != 1) {
+  if (X509_digest(x, md, dst, &len) != 1) {
     return -1;
   }
   return len;
diff --git a/src/shrpx_tls.h b/src/shrpx_tls.h
index 6fd8d2b6..87ed7f3e 100644
--- a/src/shrpx_tls.h
+++ b/src/shrpx_tls.h
@@ -269,10 +269,12 @@ int proto_version_from_string(const StringRef &v);
 int verify_ocsp_response(SSL_CTX *ssl_ctx, const uint8_t *ocsp_resp,
                          size_t ocsp_resplen);
 
-// Stores SHA-256 fingerprint of |x| in |dst| of length |dstlen|.
-// |dstlen| must be larger than 32 bytes.  This function returns the
-// number of bytes written in |dst|, or -1.
-ssize_t get_x509_fingerprint(uint8_t *dst, size_t dstlen, X509 *x);
+// Stores fingerprint of |x| in |dst| of length |dstlen|.  |md|
+// specifies hash function to use, and |dstlen| must be large enough
+// to include hash value (e.g., 32 bytes for SHA-256).  This function
+// returns the number of bytes written in |dst|, or -1.
+ssize_t get_x509_fingerprint(uint8_t *dst, size_t dstlen, const X509 *x,
+                             const EVP_MD *md);
 
 // Returns subject name of |x|.  If this function fails to get subject
 // name, it returns an empty string.