From 9d4167241c8fa15b3ae77651109aac7fa66ac17b Mon Sep 17 00:00:00 2001 From: Matt Caswell Date: Mon, 2 Jul 2018 14:09:03 +0100 Subject: Don't create an invalid CertificateRequest We should validate that the various fields we put into the CertificateRequest are not too long. Otherwise we will construct an invalid message. Fixes #6609 Reviewed-by: Rich Salz (Merged from https://github.com/openssl/openssl/pull/6628) --- ssl/ssl_locl.h | 2 ++ ssl/statem/statem_srvr.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+) (limited to 'ssl') diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h index f5b03df5a3..374fa0e521 100644 --- a/ssl/ssl_locl.h +++ b/ssl/ssl_locl.h @@ -164,6 +164,8 @@ (c)[1]=(unsigned char)(((l)>> 8)&0xff), \ (c)[2]=(unsigned char)(((l) )&0xff)),(c)+=3) +# define SSL_MAX_2_BYTE_LEN (0xffff) + /* * DTLS version numbers are strange because they're inverted. Except for * DTLS1_BAD_VER, which should be considered "lower" than the rest. diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c index 10301f1643..378eae2993 100644 --- a/ssl/statem/statem_srvr.c +++ b/ssl/statem/statem_srvr.c @@ -2006,6 +2006,11 @@ int tls_construct_certificate_request(SSL *s) const unsigned char *psigs; unsigned char *etmp = p; nl = tls12_get_psigalgs(s, 1, &psigs); + if (nl > SSL_MAX_2_BYTE_LEN) { + SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST, + SSL_R_LENGTH_TOO_LONG); + goto err; + } /* Skip over length for now */ p += 2; nl = tls12_copy_sigalgs(s, p, psigs, nl); @@ -2025,6 +2030,11 @@ int tls_construct_certificate_request(SSL *s) for (i = 0; i < sk_X509_NAME_num(sk); i++) { name = sk_X509_NAME_value(sk, i); j = i2d_X509_NAME(name, NULL); + if (j > SSL_MAX_2_BYTE_LEN) { + SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST, + SSL_R_LENGTH_TOO_LONG); + goto err; + } if (!BUF_MEM_grow_clean(buf, SSL_HM_HEADER_LENGTH(s) + n + j + 2)) { SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST, ERR_R_BUF_LIB); goto err; @@ -2034,6 +2044,11 @@ int tls_construct_certificate_request(SSL *s) i2d_X509_NAME(name, &p); n += 2 + j; nl += 2 + j; + if (nl > SSL_MAX_2_BYTE_LEN) { + SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST, + SSL_R_LENGTH_TOO_LONG); + goto err; + } } } /* else no CA names */ -- cgit v1.2.3