From a46c705214004358c8e7b1b5c3eb1c45615d3b21 Mon Sep 17 00:00:00 2001 From: Bodo Moeller Date: Wed, 15 Oct 2014 04:04:55 +0200 Subject: Support TLS_FALLBACK_SCSV. Reviewed-by: Rich Salz --- ssl/d1_lib.c | 19 ++++++++++++++++++ ssl/dtls1.h | 6 ++++-- ssl/s23_clnt.c | 3 +++ ssl/s23_srvr.c | 3 +++ ssl/s2_lib.c | 4 +++- ssl/s3_enc.c | 2 +- ssl/s3_lib.c | 28 +++++++++++++++++++++++++- ssl/ssl.h | 10 ++++++++++ ssl/ssl3.h | 7 ++++++- ssl/ssl_err.c | 2 ++ ssl/ssl_lib.c | 63 +++++++++++++++++++++++++++++++++++++++++++--------------- ssl/t1_enc.c | 1 + ssl/tls1.h | 15 ++++++++------ 13 files changed, 135 insertions(+), 28 deletions(-) (limited to 'ssl') diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c index 7d9d91ff2c..25c58a8af9 100644 --- a/ssl/d1_lib.c +++ b/ssl/d1_lib.c @@ -294,6 +294,25 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) case DTLS_CTRL_LISTEN: ret = dtls1_listen(s, parg); break; + case SSL_CTRL_CHECK_PROTO_VERSION: + /* For library-internal use; checks that the current protocol + * is the highest enabled version (according to s->ctx->method, + * as version negotiation may have changed s->method). */ + if (s->version == s->ctx->method->version) + return 1; + /* Apparently we're using a version-flexible SSL_METHOD + * (not at its highest protocol version). */ + if (s->ctx->method->version == DTLS_method()->version) + { +#if DTLS_MAX_VERSION != DTLS1_2_VERSION +# error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION. +#endif + if (!(s->options & SSL_OP_NO_DTLSv1_2)) + return s->version == DTLS1_2_VERSION; + if (!(s->options & SSL_OP_NO_DTLSv1)) + return s->version == DTLS1_VERSION; + } + return 0; /* Unexpected state; fail closed. */ default: ret = ssl3_ctrl(s, cmd, larg, parg); diff --git a/ssl/dtls1.h b/ssl/dtls1.h index c6edbe39f9..5cb79f1dac 100644 --- a/ssl/dtls1.h +++ b/ssl/dtls1.h @@ -84,8 +84,11 @@ extern "C" { #endif #define DTLS1_VERSION 0xFEFF -#define DTLS1_BAD_VER 0x0100 #define DTLS1_2_VERSION 0xFEFD +#define DTLS_MAX_VERSION DTLS1_2_VERSION + +#define DTLS1_BAD_VER 0x0100 + /* Special value for method supporting multiple versions */ #define DTLS_ANY_VERSION 0x1FFFF @@ -287,4 +290,3 @@ typedef struct dtls1_record_data_st } #endif #endif - diff --git a/ssl/s23_clnt.c b/ssl/s23_clnt.c index 5177f060c2..ca6dcd343c 100644 --- a/ssl/s23_clnt.c +++ b/ssl/s23_clnt.c @@ -748,6 +748,9 @@ static int ssl23_get_server_hello(SSL *s) goto err; } + /* ensure that TLS_MAX_VERSION is up-to-date */ + OPENSSL_assert(s->version <= TLS_MAX_VERSION); + if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING) { /* fatal alert */ diff --git a/ssl/s23_srvr.c b/ssl/s23_srvr.c index 75d814250b..6e0746691c 100644 --- a/ssl/s23_srvr.c +++ b/ssl/s23_srvr.c @@ -421,6 +421,9 @@ int ssl23_get_client_hello(SSL *s) } } + /* ensure that TLS_MAX_VERSION is up-to-date */ + OPENSSL_assert(s->version <= TLS_MAX_VERSION); + if (s->version < TLS1_2_VERSION && tls1_suiteb(s)) { SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, diff --git a/ssl/s2_lib.c b/ssl/s2_lib.c index 41ae4e8abb..41818dc6e8 100644 --- a/ssl/s2_lib.c +++ b/ssl/s2_lib.c @@ -391,6 +391,8 @@ long ssl2_ctrl(SSL *s, int cmd, long larg, void *parg) case SSL_CTRL_GET_SESSION_REUSED: ret=s->hit; break; + case SSL_CTRL_CHECK_PROTO_VERSION: + return ssl3_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, larg, parg); default: break; } @@ -434,7 +436,7 @@ int ssl2_put_cipher_by_char(const SSL_CIPHER *c, unsigned char *p) if (p != NULL) { l=c->id; - if ((l & 0xff000000) != 0x02000000) return(0); + if ((l & 0xff000000) != 0x02000000 && l != SSL3_CK_FALLBACK_SCSV) return(0); p[0]=((unsigned char)(l>>16L))&0xFF; p[1]=((unsigned char)(l>> 8L))&0xFF; p[2]=((unsigned char)(l ))&0xFF; diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c index 86f06d02c7..73f3e1730c 100644 --- a/ssl/s3_enc.c +++ b/ssl/s3_enc.c @@ -941,7 +941,7 @@ int ssl3_alert_code(int code) case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE: return(SSL3_AD_HANDSHAKE_FAILURE); case SSL_AD_BAD_CERTIFICATE_HASH_VALUE: return(SSL3_AD_HANDSHAKE_FAILURE); case SSL_AD_UNKNOWN_PSK_IDENTITY:return(TLS1_AD_UNKNOWN_PSK_IDENTITY); + case SSL_AD_INAPPROPRIATE_FALLBACK:return(TLS1_AD_INAPPROPRIATE_FALLBACK); default: return(-1); } } - diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c index a15625b911..361f295521 100644 --- a/ssl/s3_lib.c +++ b/ssl/s3_lib.c @@ -3598,6 +3598,33 @@ long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg) return (int)sess->tlsext_ecpointformatlist_length; } #endif + + case SSL_CTRL_CHECK_PROTO_VERSION: + /* For library-internal use; checks that the current protocol + * is the highest enabled version (according to s->ctx->method, + * as version negotiation may have changed s->method). */ + if (s->version == s->ctx->method->version) + return 1; + /* Apparently we're using a version-flexible SSL_METHOD + * (not at its highest protocol version). */ + if (s->ctx->method->version == SSLv23_method()->version) + { +#if TLS_MAX_VERSION != TLS1_2_VERSION +# error Code needs update for SSLv23_method() support beyond TLS1_2_VERSION. +#endif + if (!(s->options & SSL_OP_NO_TLSv1_2)) + return s->version == TLS1_2_VERSION; + if (!(s->options & SSL_OP_NO_TLSv1_1)) + return s->version == TLS1_1_VERSION; + if (!(s->options & SSL_OP_NO_TLSv1)) + return s->version == TLS1_VERSION; + if (!(s->options & SSL_OP_NO_SSLv3)) + return s->version == SSL3_VERSION; + if (!(s->options & SSL_OP_NO_SSLv2)) + return s->version == SSL2_VERSION; + } + return 0; /* Unexpected state; fail closed. */ + default: break; } @@ -4519,4 +4546,3 @@ long ssl_get_algorithm2(SSL *s) return SSL_HANDSHAKE_MAC_SHA256 | TLS1_PRF_SHA256; return alg2; } - diff --git a/ssl/ssl.h b/ssl/ssl.h index dc034d5f36..2e0df6625d 100644 --- a/ssl/ssl.h +++ b/ssl/ssl.h @@ -681,6 +681,10 @@ struct ssl_session_st */ #define SSL_MODE_SEND_CLIENTHELLO_TIME 0x00000020L #define SSL_MODE_SEND_SERVERHELLO_TIME 0x00000040L +/* Send TLS_FALLBACK_SCSV in the ClientHello. + * To be set by applications that reconnect with a downgraded protocol + * version; see draft-ietf-tls-downgrade-scsv-00 for details. */ +#define SSL_MODE_SEND_FALLBACK_SCSV 0x00000080L /* Cert related flags */ /* Many implementations ignore some aspects of the TLS standards such as @@ -1683,6 +1687,7 @@ DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION) #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE #define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY /* fatal */ +#define SSL_AD_INAPPROPRIATE_FALLBACK TLS1_AD_INAPPROPRIATE_FALLBACK /* fatal */ #define SSL_ERROR_NONE 0 #define SSL_ERROR_SSL 1 @@ -1821,6 +1826,9 @@ DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION) #define SSL_CTRL_SELECT_CURRENT_CERT 116 #define SSL_CTRL_SET_CURRENT_CERT 117 +#define SSL_CTRL_CHECK_PROTO_VERSION 119 + + #define SSL_CERT_SET_FIRST 1 #define SSL_CERT_SET_NEXT 2 #define SSL_CERT_SET_SERVER 3 @@ -2765,6 +2773,7 @@ void ERR_load_SSL_strings(void); #define SSL_R_HTTP_REQUEST 156 #define SSL_R_ILLEGAL_PADDING 283 #define SSL_R_ILLEGAL_SUITEB_DIGEST 380 +#define SSL_R_INAPPROPRIATE_FALLBACK 373 #define SSL_R_INCONSISTENT_COMPRESSION 340 #define SSL_R_INVALID_CHALLENGE_LENGTH 158 #define SSL_R_INVALID_COMMAND 280 @@ -2921,6 +2930,7 @@ void ERR_load_SSL_strings(void); #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED 1021 #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR 1051 #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION 1060 +#define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK 1086 #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY 1071 #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR 1080 #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION 1100 diff --git a/ssl/ssl3.h b/ssl/ssl3.h index 7ba8f4c130..a4823d3308 100644 --- a/ssl/ssl3.h +++ b/ssl/ssl3.h @@ -128,9 +128,14 @@ extern "C" { #endif -/* Signalling cipher suite value: from draft-ietf-tls-renegotiation-03.txt */ +/* Signalling cipher suite value from RFC 5746 + * (TLS_EMPTY_RENEGOTIATION_INFO_SCSV) */ #define SSL3_CK_SCSV 0x030000FF +/* Signalling cipher suite value from draft-ietf-tls-downgrade-scsv-00 + * (TLS_FALLBACK_SCSV) */ +#define SSL3_CK_FALLBACK_SCSV 0x03005600 + #define SSL3_CK_RSA_NULL_MD5 0x03000001 #define SSL3_CK_RSA_NULL_SHA 0x03000002 #define SSL3_CK_RSA_RC4_40_MD5 0x03000003 diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c index 1eca037175..63b5c35bea 100644 --- a/ssl/ssl_err.c +++ b/ssl/ssl_err.c @@ -398,6 +398,7 @@ static ERR_STRING_DATA SSL_str_reasons[]= {ERR_REASON(SSL_R_HTTP_REQUEST) ,"http request"}, {ERR_REASON(SSL_R_ILLEGAL_PADDING) ,"illegal padding"}, {ERR_REASON(SSL_R_ILLEGAL_SUITEB_DIGEST) ,"illegal Suite B digest"}, +{ERR_REASON(SSL_R_INAPPROPRIATE_FALLBACK),"inappropriate fallback"}, {ERR_REASON(SSL_R_INCONSISTENT_COMPRESSION),"inconsistent compression"}, {ERR_REASON(SSL_R_INVALID_CHALLENGE_LENGTH),"invalid challenge length"}, {ERR_REASON(SSL_R_INVALID_COMMAND) ,"invalid command"}, @@ -554,6 +555,7 @@ static ERR_STRING_DATA SSL_str_reasons[]= {ERR_REASON(SSL_R_TLSV1_ALERT_DECRYPTION_FAILED),"tlsv1 alert decryption failed"}, {ERR_REASON(SSL_R_TLSV1_ALERT_DECRYPT_ERROR),"tlsv1 alert decrypt error"}, {ERR_REASON(SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION),"tlsv1 alert export restriction"}, +{ERR_REASON(SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK),"tlsv1 alert inappropriate fallback"}, {ERR_REASON(SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY),"tlsv1 alert insufficient security"}, {ERR_REASON(SSL_R_TLSV1_ALERT_INTERNAL_ERROR),"tlsv1 alert internal error"}, {ERR_REASON(SSL_R_TLSV1_ALERT_NO_RENEGOTIATION),"tlsv1 alert no renegotiation"}, diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index f779ce66d7..27819b452f 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c @@ -1464,12 +1464,14 @@ int ssl_cipher_list_to_bytes(SSL *s,STACK_OF(SSL_CIPHER) *sk,unsigned char *p, SSL_CIPHER *c; CERT *ct = s->cert; unsigned char *q; - int no_scsv = s->renegotiate; + int empty_reneg_info_scsv = !s->renegotiate; /* Set disabled masks for this session */ ssl_set_client_disabled(s); if (sk == NULL) return(0); q=p; + if (put_cb == NULL) + put_cb = s->method->put_cipher_by_char; for (i=0; iid == SSL3_CK_SCSV) { - if (no_scsv) + if (!empty_reneg_info_scsv) continue; else - no_scsv = 1; + empty_reneg_info_scsv = 0; } #endif - j = put_cb ? put_cb(c,p) : ssl_put_cipher_by_char(s,c,p); + j = put_cb(c,p); p+=j; } - /* If p == q, no ciphers and caller indicates an error. Otherwise - * add SCSV if not renegotiating. - */ - if (p != q && !no_scsv) + /* If p == q, no ciphers; caller indicates an error. + * Otherwise, add applicable SCSVs. */ + if (p != q) { - static SSL_CIPHER scsv = + if (empty_reneg_info_scsv) { - 0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0 - }; - j = put_cb ? put_cb(&scsv,p) : ssl_put_cipher_by_char(s,&scsv,p); - p+=j; + static SSL_CIPHER scsv = + { + 0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0 + }; + j = put_cb(&scsv,p); + p+=j; #ifdef OPENSSL_RI_DEBUG - fprintf(stderr, "SCSV sent by client\n"); + fprintf(stderr, "TLS_EMPTY_RENEGOTIATION_INFO_SCSV sent by client\n"); #endif + } + if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) + { + static SSL_CIPHER scsv = + { + 0, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0 + }; + j = put_cb(&scsv,p); + p+=j; + } } return(p-q); @@ -1516,11 +1529,12 @@ STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,unsigned char *p,int num, const SSL_CIPHER *c; STACK_OF(SSL_CIPHER) *sk; int i,n; + if (s->s3) s->s3->send_connection_binding = 0; n=ssl_put_cipher_by_char(s,NULL,NULL); - if ((num%n) != 0) + if (n == 0 || (num%n) != 0) { SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST); return(NULL); @@ -1545,7 +1559,7 @@ STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,unsigned char *p,int num, for (i=0; is3 && (n != 3 || !p[0]) && (p[n-2] == ((SSL3_CK_SCSV >> 8) & 0xff)) && (p[n-1] == (SSL3_CK_SCSV & 0xff))) @@ -1565,6 +1579,23 @@ STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,unsigned char *p,int num, continue; } + /* Check for TLS_FALLBACK_SCSV */ + if ((n != 3 || !p[0]) && + (p[n-2] == ((SSL3_CK_FALLBACK_SCSV >> 8) & 0xff)) && + (p[n-1] == (SSL3_CK_FALLBACK_SCSV & 0xff))) + { + /* The SCSV indicates that the client previously tried a higher version. + * Fail if the current version is an unexpected downgrade. */ + if (!SSL_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, 0, NULL)) + { + SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,SSL_R_INAPPROPRIATE_FALLBACK); + if (s->s3) + ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_INAPPROPRIATE_FALLBACK); + goto err; + } + continue; + } + c=ssl_get_cipher_by_char(s,p); p+=n; if (c != NULL) diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c index 10fc795acd..7974762d4c 100644 --- a/ssl/t1_enc.c +++ b/ssl/t1_enc.c @@ -1286,6 +1286,7 @@ int tls1_alert_code(int code) case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE: return(TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE); case SSL_AD_BAD_CERTIFICATE_HASH_VALUE: return(TLS1_AD_BAD_CERTIFICATE_HASH_VALUE); case SSL_AD_UNKNOWN_PSK_IDENTITY:return(TLS1_AD_UNKNOWN_PSK_IDENTITY); + case SSL_AD_INAPPROPRIATE_FALLBACK:return(TLS1_AD_INAPPROPRIATE_FALLBACK); #if 0 /* not appropriate for TLS, not used for DTLS */ case DTLS1_AD_MISSING_HANDSHAKE_MESSAGE: return (DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); diff --git a/ssl/tls1.h b/ssl/tls1.h index 09d1763f5b..3c8de73032 100644 --- a/ssl/tls1.h +++ b/ssl/tls1.h @@ -159,17 +159,19 @@ extern "C" { #define TLS1_ALLOW_EXPERIMENTAL_CIPHERSUITES 0 +#define TLS1_VERSION 0x0301 +#define TLS1_1_VERSION 0x0302 #define TLS1_2_VERSION 0x0303 -#define TLS1_2_VERSION_MAJOR 0x03 -#define TLS1_2_VERSION_MINOR 0x03 +#define TLS_MAX_VERSION TLS1_2_VERSION + +#define TLS1_VERSION_MAJOR 0x03 +#define TLS1_VERSION_MINOR 0x01 -#define TLS1_1_VERSION 0x0302 #define TLS1_1_VERSION_MAJOR 0x03 #define TLS1_1_VERSION_MINOR 0x02 -#define TLS1_VERSION 0x0301 -#define TLS1_VERSION_MAJOR 0x03 -#define TLS1_VERSION_MINOR 0x01 +#define TLS1_2_VERSION_MAJOR 0x03 +#define TLS1_2_VERSION_MINOR 0x03 #define TLS1_get_version(s) \ ((s->version >> 8) == TLS1_VERSION_MAJOR ? s->version : 0) @@ -187,6 +189,7 @@ extern "C" { #define TLS1_AD_PROTOCOL_VERSION 70 /* fatal */ #define TLS1_AD_INSUFFICIENT_SECURITY 71 /* fatal */ #define TLS1_AD_INTERNAL_ERROR 80 /* fatal */ +#define TLS1_AD_INAPPROPRIATE_FALLBACK 86 /* fatal */ #define TLS1_AD_USER_CANCELLED 90 #define TLS1_AD_NO_RENEGOTIATION 100 /* codes 110-114 are from RFC3546 */ -- cgit v1.2.3