diff options
| author | Dr. Stephen Henson <steve@openssl.org> | 2014-10-23 17:09:57 +0100 |
|---|---|---|
| committer | Dr. Stephen Henson <steve@openssl.org> | 2015-01-06 12:45:10 +0000 |
| commit | 4b4c1fcc88aec8c9e001b0a0077d3cd4de1ed0e6 (patch) | |
| tree | fa6353c22986ad01b6e62d1a460d9edd5628e1c1 /ssl | |
| parent | 1cfd7cf3ccd86566845b416fd87167536cc8cd90 (diff) | |
Only allow ephemeral RSA keys in export ciphersuites.
OpenSSL clients would tolerate temporary RSA keys in non-export
ciphersuites. It also had an option SSL_OP_EPHEMERAL_RSA which
enabled this server side. Remove both options as they are a
protocol violation.
Thanks to Karthikeyan Bhargavan for reporting this issue.
(CVE-2015-0204)
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
Diffstat (limited to 'ssl')
| -rw-r--r-- | ssl/d1_srvr.c | 21 | ||||
| -rw-r--r-- | ssl/s3_clnt.c | 7 | ||||
| -rw-r--r-- | ssl/s3_srvr.c | 21 | ||||
| -rw-r--r-- | ssl/ssl.h | 5 |
4 files changed, 21 insertions, 33 deletions
diff --git a/ssl/d1_srvr.c b/ssl/d1_srvr.c index ce73f24a73..8e8f94c847 100644 --- a/ssl/d1_srvr.c +++ b/ssl/d1_srvr.c @@ -472,24 +472,15 @@ int dtls1_accept(SSL *s) case SSL3_ST_SW_KEY_EXCH_B: alg_k = s->s3->tmp.new_cipher->algorithm_mkey; - /* clear this, it may get reset by - * send_server_key_exchange */ - if ((s->options & SSL_OP_EPHEMERAL_RSA) -#ifndef OPENSSL_NO_KRB5 - && !(alg_k & SSL_kKRB5) -#endif /* OPENSSL_NO_KRB5 */ - ) - /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key - * even when forbidden by protocol specs - * (handshake may fail as clients are not required to - * be able to handle this) */ - s->s3->tmp.use_rsa_tmp=1; - else - s->s3->tmp.use_rsa_tmp=0; + /* + * clear this, it may get reset by + * send_server_key_exchange + */ + s->s3->tmp.use_rsa_tmp=0; /* only send if a DH key exchange or * RSA but we have a sign only certificate */ - if (s->s3->tmp.use_rsa_tmp + if (0 /* PSK: send ServerKeyExchange if PSK identity * hint if provided */ #ifndef OPENSSL_NO_PSK diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c index 6de971b226..77f61f1dd0 100644 --- a/ssl/s3_clnt.c +++ b/ssl/s3_clnt.c @@ -1623,6 +1623,13 @@ int ssl3_get_key_exchange(SSL *s) #ifndef OPENSSL_NO_RSA if (alg_k & SSL_kRSA) { + /* Temporary RSA keys only allowed in export ciphersuites */ + if (!SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)) + { + al=SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE,SSL_R_UNEXPECTED_MESSAGE); + goto f_err; + } if ((rsa=RSA_new()) == NULL) { SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE,ERR_R_MALLOC_FAILURE); diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c index 01c982893e..9a10a7cbfa 100644 --- a/ssl/s3_srvr.c +++ b/ssl/s3_srvr.c @@ -446,20 +446,11 @@ int ssl3_accept(SSL *s) case SSL3_ST_SW_KEY_EXCH_B: alg_k = s->s3->tmp.new_cipher->algorithm_mkey; - /* clear this, it may get reset by - * send_server_key_exchange */ - if ((s->options & SSL_OP_EPHEMERAL_RSA) -#ifndef OPENSSL_NO_KRB5 - && !(alg_k & SSL_kKRB5) -#endif /* OPENSSL_NO_KRB5 */ - ) - /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key - * even when forbidden by protocol specs - * (handshake may fail as clients are not required to - * be able to handle this) */ - s->s3->tmp.use_rsa_tmp=1; - else - s->s3->tmp.use_rsa_tmp=0; + /* + * clear this, it may get reset by + * send_server_key_exchange + */ + s->s3->tmp.use_rsa_tmp=0; /* only send if a DH key exchange, fortezza or @@ -473,7 +464,7 @@ int ssl3_accept(SSL *s) * server certificate contains the server's * public key for key exchange. */ - if (s->s3->tmp.use_rsa_tmp + if (0 /* PSK: send ServerKeyExchange if PSK identity * hint if provided */ #ifndef OPENSSL_NO_PSK @@ -622,9 +622,8 @@ struct ssl_session_st #define SSL_OP_SINGLE_ECDH_USE 0x00080000L /* If set, always create a new key when using tmp_dh parameters */ #define SSL_OP_SINGLE_DH_USE 0x00100000L -/* Set to always use the tmp_rsa key when doing RSA operations, - * even when this violates protocol specs */ -#define SSL_OP_EPHEMERAL_RSA 0x00200000L +/* Does nothing: retained for compatibiity */ +#define SSL_OP_EPHEMERAL_RSA 0x0 /* Set on servers to choose the cipher according to the server's * preferences */ #define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L |