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*) Disable code workaround for ancient and obsolete Netscape browsers |
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and servers: an attacker can use it in a ciphersuite downgrade attack. |
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Thanks to Martin Rex for discovering this bug. CVE-2010-4180 |
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diff -up openssl-fips-0.9.8e/doc/ssl/SSL_CTX_set_options.pod.disable-nsbug openssl-fips-0.9.8e/doc/ssl/SSL_CTX_set_options.pod |
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--- openssl-fips-0.9.8e/doc/ssl/SSL_CTX_set_options.pod.disable-nsbug 2010-12-07 17:45:32.000000000 +0100 |
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+++ openssl-fips-0.9.8e/doc/ssl/SSL_CTX_set_options.pod 2010-12-07 17:45:33.000000000 +0100 |
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@@ -78,18 +78,7 @@ this breaks this server so 16 bytes is t |
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|
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=item SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG |
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|
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-ssl3.netscape.com:443, first a connection is established with RC4-MD5. |
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-If it is then resumed, we end up using DES-CBC3-SHA. It should be |
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-RC4-MD5 according to 7.6.1.3, 'cipher_suite'. |
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- |
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-Netscape-Enterprise/2.01 (https://merchant.netscape.com) has this bug. |
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-It only really shows up when connecting via SSLv2/v3 then reconnecting |
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-via SSLv3. The cipher list changes.... |
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- |
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-NEW INFORMATION. Try connecting with a cipher list of just |
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-DES-CBC-SHA:RC4-MD5. For some weird reason, each new connection uses |
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-RC4-MD5, but a re-connect tries to use DES-CBC-SHA. So netscape, when |
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-doing a re-connect, always takes the first cipher in the cipher list. |
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+This option has no effect anymore. |
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|
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=item SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG |
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|
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diff -up openssl-fips-0.9.8e/ssl/ssl.h.disable-nsbug openssl-fips-0.9.8e/ssl/ssl.h |
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--- openssl-fips-0.9.8e/ssl/ssl.h.disable-nsbug 2010-12-07 17:45:32.000000000 +0100 |
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+++ openssl-fips-0.9.8e/ssl/ssl.h 2010-12-07 17:45:33.000000000 +0100 |
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@@ -482,7 +482,7 @@ typedef struct ssl_session_st |
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#define SSL_OP_NETSCAPE_CHALLENGE_BUG 0x00000002L |
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/* Allow initial connection to servers that don't support RI */ |
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#define SSL_OP_LEGACY_SERVER_CONNECT 0x00000004L |
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-#define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0x00000008L /* can break some security expectations */ |
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+#define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0x00000008L /* no effect anymore */ |
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#define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0x00000010L |
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#define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0x00000020L |
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#define SSL_OP_MSIE_SSLV2_RSA_PADDING 0x00000040L /* no effect since 0.9.7h and 0.9.8b */ |
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diff -up openssl-fips-0.9.8e/ssl/s3_clnt.c.disable-nsbug openssl-fips-0.9.8e/ssl/s3_clnt.c |
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--- openssl-fips-0.9.8e/ssl/s3_clnt.c.disable-nsbug 2010-12-07 17:45:32.000000000 +0100 |
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+++ openssl-fips-0.9.8e/ssl/s3_clnt.c 2010-12-07 17:45:33.000000000 +0100 |
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@@ -752,8 +752,11 @@ int ssl3_get_server_hello(SSL *s) |
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s->session->cipher_id = s->session->cipher->id; |
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if (s->hit && (s->session->cipher_id != c->id)) |
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{ |
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+/* Workaround is now obsolete */ |
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+#if 0 |
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if (!(s->options & |
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SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG)) |
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+#endif |
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{ |
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al=SSL_AD_ILLEGAL_PARAMETER; |
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SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED); |
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diff -up openssl-fips-0.9.8e/ssl/s3_srvr.c.disable-nsbug openssl-fips-0.9.8e/ssl/s3_srvr.c |
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--- openssl-fips-0.9.8e/ssl/s3_srvr.c.disable-nsbug 2010-12-07 17:46:11.000000000 +0100 |
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+++ openssl-fips-0.9.8e/ssl/s3_srvr.c 2010-12-07 17:46:15.000000000 +0100 |
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@@ -870,12 +870,14 @@ int ssl3_get_client_hello(SSL *s) |
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} |
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if (j == 0) |
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{ |
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+#if 0 |
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if ((s->options & SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG) && (sk_SSL_CIPHER_num(ciphers) == 1)) |
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{ |
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/* Very bad for multi-threading.... */ |
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s->session->cipher=sk_SSL_CIPHER_value(ciphers, 0); |
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} |
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else |
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+#endif |
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{ |
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/* we need to have the cipher in the cipher |
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* list if we are asked to reuse it */ |