Fix TLS 1.2 sigalgs fallback logic for ECDSA.

Also fix up those tests as they were a little confused. It is always the
shim that signs and has a configured certificate in these tests.

BUG=95

Change-Id: I57a6b1bad19986c79cd30aaa6cf3b8ca307ef8b2
Reviewed-on: https://boringssl-review.googlesource.com/10444
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

ssl/t1_lib.c

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index dc6c6dd..54d5bdf 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -3070,7 +3070,7 @@
                                                       SSL_SIGN_ECDSA_SHA1};
     peer_sigalgs = kDefaultPeerAlgorithms;
     peer_sigalgs_len =
-        sizeof(kDefaultPeerAlgorithms) / sizeof(kDefaultPeerAlgorithms);
+        sizeof(kDefaultPeerAlgorithms) / sizeof(kDefaultPeerAlgorithms[0]);
   }
 
   for (i = 0; i < sigalgs_len; i++) {

ssl/test/runner/runner.go

diff --git a/ssl/test/runner/runner.go b/ssl/test/runner/runner.go
index f999f48..4c7d2e7 100644
--- a/ssl/test/runner/runner.go
+++ b/ssl/test/runner/runner.go
@@ -5814,7 +5814,7 @@
 	// Test that, if the list is missing, the peer falls back to SHA-1 in
 	// TLS 1.2, but not TLS 1.3.
 	testCases = append(testCases, testCase{
-		name: "ClientAuth-SHA1-Fallback",
+		name: "ClientAuth-SHA1-Fallback-RSA",
 		config: Config{
 			MaxVersion: VersionTLS12,
 			ClientAuth: RequireAnyClientCert,
@@ -5833,10 +5833,9 @@
 
 	testCases = append(testCases, testCase{
 		testType: serverTest,
-		name:     "ServerAuth-SHA1-Fallback",
+		name:     "ServerAuth-SHA1-Fallback-RSA",
 		config: Config{
-			MaxVersion:   VersionTLS12,
-			CipherSuites: []uint16{TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256},
+			MaxVersion: VersionTLS12,
 			VerifySignatureAlgorithms: []signatureAlgorithm{
 				signatureRSAPKCS1WithSHA1,
 			},
@@ -5844,6 +5843,46 @@
 				NoSignatureAlgorithms: true,
 			},
 		},
+		flags: []string{
+			"-cert-file", path.Join(*resourceDir, rsaCertificateFile),
+			"-key-file", path.Join(*resourceDir, rsaKeyFile),
+		},
+	})
+
+	testCases = append(testCases, testCase{
+		name: "ClientAuth-SHA1-Fallback-ECDSA",
+		config: Config{
+			MaxVersion: VersionTLS12,
+			ClientAuth: RequireAnyClientCert,
+			VerifySignatureAlgorithms: []signatureAlgorithm{
+				signatureECDSAWithSHA1,
+			},
+			Bugs: ProtocolBugs{
+				NoSignatureAlgorithms: true,
+			},
+		},
+		flags: []string{
+			"-cert-file", path.Join(*resourceDir, ecdsaP256CertificateFile),
+			"-key-file", path.Join(*resourceDir, ecdsaP256KeyFile),
+		},
+	})
+
+	testCases = append(testCases, testCase{
+		testType: serverTest,
+		name:     "ServerAuth-SHA1-Fallback-ECDSA",
+		config: Config{
+			MaxVersion: VersionTLS12,
+			VerifySignatureAlgorithms: []signatureAlgorithm{
+				signatureECDSAWithSHA1,
+			},
+			Bugs: ProtocolBugs{
+				NoSignatureAlgorithms: true,
+			},
+		},
+		flags: []string{
+			"-cert-file", path.Join(*resourceDir, ecdsaP256CertificateFile),
+			"-key-file", path.Join(*resourceDir, ecdsaP256KeyFile),
+		},
 	})
 
 	testCases = append(testCases, testCase{