commit 8662f940230bb0f8989ddc993488cde3a9c5b76a
author deadbeef <deadbeef@webrtc.org> Fri Jan 20 21:20:51 2017 -0800
committer Commit bot <commit-bot@chromium.org> Sat Jan 21 05:20:51 2017 +0000
tree 71f082cec138e33a29f3db54bd8d9ae2842fafc2
parent 2197e9186087012fb677a5865a42835297cdea19

Only set certificate on DTLS transport if fingerprint is found in SDP.

This is used for fallback from DTLS to SDES encryption, which we probably still
want to support. Setting a certificate puts the DTLS transport in a "DTLS
enabled" mode, so it should be delayed until SDP with "a=fingerprint" is set.

BUG=webrtc:6972

Review-Url: https://codereview.webrtc.org/2641633002
Cr-Commit-Position: refs/heads/master@{#16199}

webrtc/base/sslfingerprint.cc

diff --git a/webrtc/base/sslfingerprint.cc b/webrtc/base/sslfingerprint.cc
index 2c3e1e9..e172a2c 100644
--- a/webrtc/base/sslfingerprint.cc
+++ b/webrtc/base/sslfingerprint.cc
@@ -14,6 +14,7 @@
 #include <string>
 
 #include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
 #include "webrtc/base/messagedigest.h"
 #include "webrtc/base/stringencode.h"
 
@@ -62,6 +63,22 @@
                             value_len);
 }
 
+SSLFingerprint* SSLFingerprint::CreateFromCertificate(
+    const RTCCertificate* cert) {
+  std::string digest_alg;
+  if (!cert->ssl_certificate().GetSignatureDigestAlgorithm(&digest_alg)) {
+    LOG(LS_ERROR) << "Failed to retrieve the certificate's digest algorithm";
+    return nullptr;
+  }
+
+  SSLFingerprint* fingerprint = Create(digest_alg, cert->identity());
+  if (!fingerprint) {
+    LOG(LS_ERROR) << "Failed to create identity fingerprint, alg="
+                  << digest_alg;
+  }
+  return fingerprint;
+}
+
 SSLFingerprint::SSLFingerprint(const std::string& algorithm,
                                const uint8_t* digest_in,
                                size_t digest_len)

webrtc/base/sslfingerprint.h

diff --git a/webrtc/base/sslfingerprint.h b/webrtc/base/sslfingerprint.h
index 4ffb2b0..62b4bc8 100644
--- a/webrtc/base/sslfingerprint.h
+++ b/webrtc/base/sslfingerprint.h
@@ -15,6 +15,7 @@
 
 #include "webrtc/base/basictypes.h"
 #include "webrtc/base/copyonwritebuffer.h"
+#include "webrtc/base/rtccertificate.h"
 #include "webrtc/base/sslidentity.h"
 
 namespace rtc {
@@ -31,6 +32,10 @@
   static SSLFingerprint* CreateFromRfc4572(const std::string& algorithm,
                                            const std::string& fingerprint);
 
+  // Creates a fingerprint from a certificate, using the same digest algorithm
+  // as the certificate's signature.
+  static SSLFingerprint* CreateFromCertificate(const RTCCertificate* cert);
+
   SSLFingerprint(const std::string& algorithm,
                  const uint8_t* digest_in,
                  size_t digest_len);