1 diff -pu a/nss/lib/ssl/ssl3con.c b/nss/lib/ssl/ssl3con.c
2 --- a/nss/lib/ssl/ssl3con.c 2014-01-17 18:46:51.999581198 -0800
3 +++ b/nss/lib/ssl/ssl3con.c 2014-01-17 18:47:05.509804656 -0800
4 @@ -3473,6 +3473,9 @@ ssl3_HandleAlert(sslSocket *ss, sslBuffe
5 case certificate_unknown: error = SSL_ERROR_CERTIFICATE_UNKNOWN_ALERT;
7 case illegal_parameter: error = SSL_ERROR_ILLEGAL_PARAMETER_ALERT;break;
8 + case inappropriate_fallback:
9 + error = SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT;
12 /* All alerts below are TLS only. */
13 case unknown_ca: error = SSL_ERROR_UNKNOWN_CA_ALERT; break;
14 @@ -4986,6 +4989,7 @@ ssl3_SendClientHello(sslSocket *ss, PRBo
17 PRBool isTLS = PR_FALSE;
18 + PRBool requestingResume = PR_FALSE, fallbackSCSV = PR_FALSE;
19 PRInt32 total_exten_len = 0;
20 unsigned paddingExtensionLen;
21 unsigned numCompressionMethods;
22 @@ -5128,6 +5132,7 @@ ssl3_SendClientHello(sslSocket *ss, PRBo
26 + requestingResume = PR_TRUE;
27 SSL_AtomicIncrementLong(& ssl3stats.sch_sid_cache_hits );
29 PRINT_BUF(4, (ss, "client, found session-id:", sid->u.ssl3.sessionID,
30 @@ -5246,8 +5251,15 @@ ssl3_SendClientHello(sslSocket *ss, PRBo
31 if (sid->u.ssl3.lock) { PR_RWLock_Unlock(sid->u.ssl3.lock); }
32 return SECFailure; /* count_cipher_suites has set error code. */
35 + fallbackSCSV = ss->opt.enableFallbackSCSV && (!requestingResume ||
36 + ss->version < sid->version);
37 + /* make room for SCSV */
38 if (ss->ssl3.hs.sendingSCSV) {
39 - ++num_suites; /* make room for SCSV */
46 /* count compression methods */
47 @@ -5389,11 +5389,21 @@ ssl3_SendClientHello(sslSocket *ss, PRBo
48 if (rv != SECSuccess) {
49 if (sid->u.ssl3.lock) { NSSRWLock_UnlockRead(sid->u.ssl3.lock); }
50 return rv; /* err set by ssl3_AppendHandshake* */
56 + rv = ssl3_AppendHandshakeNumber(ss, TLS_FALLBACK_SCSV,
57 + sizeof(ssl3CipherSuite));
58 + if (rv != SECSuccess) {
59 + if (sid->u.ssl3.lock) { PR_RWLock_Unlock(sid->u.ssl3.lock); }
60 + return rv; /* err set by ssl3_AppendHandshake* */
65 /* if cards were removed or inserted between count_cipher_suites and
66 * generating our list, detect the error here rather than send it off to
68 if (actual_count != num_suites) {
69 @@ -8084,6 +8105,19 @@ ssl3_HandleClientHello(sslSocket *ss, SS
70 goto loser; /* malformed */
73 + /* If the ClientHello version is less than our maximum version, check for a
74 + * TLS_FALLBACK_SCSV and reject the connection if found. */
75 + if (ss->vrange.max > ss->clientHelloVersion) {
76 + for (i = 0; i + 1 < suites.len; i += 2) {
77 + PRUint16 suite_i = (suites.data[i] << 8) | suites.data[i + 1];
78 + if (suite_i != TLS_FALLBACK_SCSV)
80 + desc = inappropriate_fallback;
81 + errCode = SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT;
86 /* grab the list of compression methods. */
87 rv = ssl3_ConsumeHandshakeVariable(ss, &comps, 1, &b, &length);
88 if (rv != SECSuccess) {
89 diff -pu a/nss/lib/ssl/ssl3prot.h b/nss/lib/ssl/ssl3prot.h
90 --- a/nss/lib/ssl/ssl3prot.h 2014-01-17 17:59:03.242109996 -0800
91 +++ b/nss/lib/ssl/ssl3prot.h 2014-01-17 18:47:05.509804656 -0800
92 @@ -98,6 +98,7 @@ typedef enum {
93 protocol_version = 70,
94 insufficient_security = 71,
96 + inappropriate_fallback = 86, /* could also be sent for SSLv3 */
98 no_renegotiation = 100,
100 diff -pu a/nss/lib/ssl/sslerr.h b/nss/lib/ssl/sslerr.h
101 --- a/nss/lib/ssl/sslerr.h 2014-01-17 17:59:03.242109996 -0800
102 +++ b/nss/lib/ssl/sslerr.h 2014-01-17 18:47:05.509804656 -0800
103 @@ -196,6 +196,7 @@ SSL_ERROR_INCORRECT_SIGNATURE_ALGORITHM
104 SSL_ERROR_BAD_CHANNEL_ID_DATA = (SSL_ERROR_BASE + 129),
105 SSL_ERROR_INVALID_CHANNEL_ID_KEY = (SSL_ERROR_BASE + 130),
106 SSL_ERROR_GET_CHANNEL_ID_FAILED = (SSL_ERROR_BASE + 131),
107 +SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT = (SSL_ERROR_BASE + 132),
109 SSL_ERROR_END_OF_LIST /* let the c compiler determine the value of this. */
111 diff -pu a/nss/lib/ssl/SSLerrs.h b/nss/lib/ssl/SSLerrs.h
112 --- a/nss/lib/ssl/SSLerrs.h 2014-01-17 17:59:03.242109996 -0800
113 +++ b/nss/lib/ssl/SSLerrs.h 2014-01-17 18:47:05.509804656 -0800
114 @@ -421,3 +421,8 @@ ER3(SSL_ERROR_INVALID_CHANNEL_ID_KEY, (S
116 ER3(SSL_ERROR_GET_CHANNEL_ID_FAILED, (SSL_ERROR_BASE + 131),
117 "The application could not get a TLS Channel ID.")
119 +ER3(SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT, (SSL_ERROR_BASE + 132),
120 +"The connection was using a lesser TLS version as a result of a previous"
121 +" handshake failure, but the server indicated that it should not have been"
123 diff -pu a/nss/lib/ssl/ssl.h b/nss/lib/ssl/ssl.h
124 --- a/nss/lib/ssl/ssl.h 2014-01-17 18:46:51.999581198 -0800
125 +++ b/nss/lib/ssl/ssl.h 2014-01-17 18:48:54.971613341 -0800
126 @@ -183,6 +183,8 @@ SSL_IMPORT PRFileDesc *DTLS_ImportFD(PRF
128 /* Request Signed Certificate Timestamps via TLS extension (client) */
129 #define SSL_ENABLE_SIGNED_CERT_TIMESTAMPS 27
130 +#define SSL_ENABLE_FALLBACK_SCSV 28 /* Send fallback SCSV in
133 #ifdef SSL_DEPRECATED_FUNCTION
134 /* Old deprecated function names */
135 diff -pu a/nss/lib/ssl/sslimpl.h b/nss/lib/ssl/sslimpl.h
136 --- a/nss/lib/ssl/sslimpl.h 2014-01-17 18:46:51.999581198 -0800
137 +++ b/nss/lib/ssl/sslimpl.h 2014-01-17 18:51:17.963962287 -0800
138 @@ -338,6 +338,7 @@ typedef struct sslOptionsStr {
139 unsigned int enableNPN : 1; /* 26 */
140 unsigned int enableALPN : 1; /* 27 */
141 unsigned int enableSignedCertTimestamps : 1; /* 28 */
142 + unsigned int enableFallbackSCSV : 1; /* 29 */
145 typedef enum { sslHandshakingUndetermined = 0,
146 diff -pu a/nss/lib/ssl/sslproto.h b/nss/lib/ssl/sslproto.h
147 --- a/nss/lib/ssl/sslproto.h 2014-01-17 18:10:16.793281867 -0800
148 +++ b/nss/lib/ssl/sslproto.h 2014-01-17 18:47:05.509804656 -0800
151 #define TLS_EMPTY_RENEGOTIATION_INFO_SCSV 0x00FF
153 +/* TLS_FALLBACK_SCSV is a signaling cipher suite value that indicates that a
154 + * handshake is the result of TLS version fallback. This value is not IANA
156 +#define TLS_FALLBACK_SCSV 0x5600
158 /* Cipher Suite Values starting with 0xC000 are defined in informational
161 diff -pu a/nss/lib/ssl/sslsock.c b/nss/lib/ssl/sslsock.c
162 --- a/nss/lib/ssl/sslsock.c 2014-01-17 18:46:52.009581364 -0800
163 +++ b/nss/lib/ssl/sslsock.c 2014-01-17 18:59:17.931852364 -0800
164 @@ -88,7 +88,8 @@ static sslOptions ssl_defaults = {
165 PR_FALSE, /* enableOCSPStapling */
166 PR_TRUE, /* enableNPN */
167 PR_FALSE, /* enableALPN */
168 - PR_FALSE /* enableSignedCertTimestamps */
169 + PR_FALSE, /* enableSignedCertTimestamps */
170 + PR_FALSE /* enableFallbackSCSV */
174 @@ -792,6 +793,10 @@ SSL_OptionSet(PRFileDesc *fd, PRInt32 wh
175 ss->opt.enableSignedCertTimestamps = on;
178 + case SSL_ENABLE_FALLBACK_SCSV:
179 + ss->opt.enableFallbackSCSV = on;
183 PORT_SetError(SEC_ERROR_INVALID_ARGS);
185 @@ -867,6 +872,7 @@ SSL_OptionGet(PRFileDesc *fd, PRInt32 wh
186 case SSL_ENABLE_SIGNED_CERT_TIMESTAMPS:
187 on = ss->opt.enableSignedCertTimestamps;
189 + case SSL_ENABLE_FALLBACK_SCSV: on = ss->opt.enableFallbackSCSV; break;
192 PORT_SetError(SEC_ERROR_INVALID_ARGS);
193 @@ -933,6 +939,9 @@ SSL_OptionGetDefault(PRInt32 which, PRBo
194 case SSL_ENABLE_SIGNED_CERT_TIMESTAMPS:
195 on = ssl_defaults.enableSignedCertTimestamps;
197 + case SSL_ENABLE_FALLBACK_SCSV:
198 + on = ssl_defaults.enableFallbackSCSV;
202 PORT_SetError(SEC_ERROR_INVALID_ARGS);
203 @@ -1112,6 +1121,10 @@ SSL_OptionSetDefault(PRInt32 which, PRBo
204 ssl_defaults.enableSignedCertTimestamps = on;
207 + case SSL_ENABLE_FALLBACK_SCSV:
208 + ssl_defaults.enableFallbackSCSV = on;
212 PORT_SetError(SEC_ERROR_INVALID_ARGS);