X-Git-Url: http://sjero.net/git/?p=wget;a=blobdiff_plain;f=src%2Fopenssl.c;h=de335c086a021aec355014f7a7aa25b1bbaece93;hp=dd3a62a4ee0cf594f97cc35655be548e259dd3c4;hb=57c9e17e6cfef9bc0e8ab9fa8edf9d131a233e57;hpb=61a4b1f77a3412dbd9a3864d8422addf94459fd1 diff --git a/src/openssl.c b/src/openssl.c index dd3a62a4..de335c08 100644 --- a/src/openssl.c +++ b/src/openssl.c @@ -571,32 +571,8 @@ ssl_check_certificate (int fd, const char *host) X509_NAME *xname = X509_get_subject_name(cert); common_name[0] = '\0'; - X509_NAME_get_text_by_NID (xname, - NID_commonName, common_name, sizeof (common_name)); - - /* We now determine the length of the ASN1 string. If it differs from - * common_name's length, then there is a \0 before the string terminates. - * This can be an instance of a null-prefix attack [0]. - * - * [0] https://www.blackhat.com/html/bh-usa-09/bh-usa-09-archives.html#Marlinspike - * */ - - int i=-1,j; - if(xname) { - for(;(j=X509_NAME_get_index_by_NID (xname, NID_commonName, i))!=-1;i=j); - } - - X509_NAME_ENTRY *xentry = X509_NAME_get_entry(xname,i); - ASN1_STRING *sdata = X509_NAME_ENTRY_get_data(xentry); - - if (strlen(common_name) != ASN1_STRING_length(sdata)) - { - logprintf (LOG_NOTQUIET, _("\ -%s: certificate common name is invalid. It is possible that someone is \ -eavesdropping on you (man-in-the-middle attack)!\n"), - severity); - success = false; - } + X509_NAME_get_text_by_NID (xname, NID_commonName, common_name, + sizeof (common_name)); if (!pattern_match (common_name, host)) { @@ -605,6 +581,41 @@ eavesdropping on you (man-in-the-middle attack)!\n"), severity, quote (common_name), quote (host)); success = false; } + else + { + /* We now determine the length of the ASN1 string. If it differs from + * common_name's length, then there is a \0 before the string terminates. + * This can be an instance of a null-prefix attack. + * + * https://www.blackhat.com/html/bh-usa-09/bh-usa-09-archives.html#Marlinspike + * */ + + int i = -1, j; + X509_NAME_ENTRY *xentry; + ASN1_STRING *sdata; + + if (xname) { + for (;;) + { + j = X509_NAME_get_index_by_NID (xname, NID_commonName, i); + if (j == -1) break; + i = j; + } + } + + xentry = X509_NAME_get_entry(xname,i); + sdata = X509_NAME_ENTRY_get_data(xentry); + if (strlen (common_name) != ASN1_STRING_length (sdata)) + { + logprintf (LOG_NOTQUIET, _("\ +%s: certificate common name is invalid (contains a NUL character).\n\ +This may be an indication that the host is not who it claims to be\n\ +(that is, it is not the real %s).\n"), + severity, quote (host)); + success = false; + } + } + if (success) DEBUGP (("X509 certificate successfully verified and matches host %s\n",