PR: 1942

Submitted by: David Woodhouse <dwmw2@infradead.org>
Approved by: steve@openssl.org

Replace ad-hoc chain builder with X509_verify_cert().

diff --git a/CHANGES b/CHANGES
index e60f704aac1b8d0c296079f12dbf1b5b909a8560..3ef82e6eb1c403045ad31e1078beaadbcec2e965 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -9,6 +9,11 @@
      clash.
      [Guenter <lists@gknw.net>]
 
+  *) Fix the server certificate chain building code to use X509_verify_cert(),
+     it used to have an ad-hoc builder which was unable to cope with anything
+     other than a simple chain.
+     [David Woodhouse <dwmw2@infradead.org>, Steve Henson]
+
   *) Don't check self signed certificate signatures in X509_verify_cert()
      by default (a flag can override this): it just wastes time without
      adding any security. As a useful side effect self signed root CAs

diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 69b6b10ba22e614304f6bf0031d072eda7247c6f..996f3a77b3d5ca4a0c1c6b9e2fb26920b303f3d0 100644 (file)
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -815,14 +815,30 @@ int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
        return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
        }
 
+static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
+       {
+               int n;
+               unsigned char *p;
+
+               n=i2d_X509(x,NULL);
+               if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
+                       {
+                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
+                       return 0;
+                       }
+               p=(unsigned char *)&(buf->data[*l]);
+               l2n3(n,p);
+               i2d_X509(x,&p);
+               *l+=n+3;
+
+               return 1;
+       }
 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
        {
        unsigned char *p;
-       int n,i;
+       int i;
        unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
        BUF_MEM *buf;
-       X509_STORE_CTX xs_ctx;
-       X509_OBJECT obj;
 
        /* TLSv1 sends a chain with nothing in it, instead of an alert */
        buf=s->init_buf;
@@ -833,54 +849,33 @@ unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
                }
        if (x != NULL)
                {
-               if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
-                       {
-                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
-                       return(0);
-                       }
-
-               for (;;)
-                       {
-                       n=i2d_X509(x,NULL);
-                       if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
-                               {
-                               SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
-                               return(0);
-                               }
-                       p=(unsigned char *)&(buf->data[l]);
-                       l2n3(n,p);
-                       i2d_X509(x,&p);
-                       l+=n+3;
-                       if (X509_NAME_cmp(X509_get_subject_name(x),
-                               X509_get_issuer_name(x)) == 0) break;
-
-                       i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
-                               X509_get_issuer_name(x),&obj);
-                       if (i <= 0) break;
-                       x=obj.data.x509;
-                       /* Count is one too high since the X509_STORE_get uped the
-                        * ref count */
-                       X509_free(x);
-                       }
-
-               X509_STORE_CTX_cleanup(&xs_ctx);
-               }
-
+               X509_STORE_CTX xs_ctx;
+  
+               if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
+                       {
+                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
+                       return(0);
+                       }
+  
+               X509_verify_cert(&xs_ctx);
+               for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
+                       {
+                       x = sk_X509_value(xs_ctx.chain, i);
+
+                       if (!dtls1_add_cert_to_buf(buf, &l, x))
+                               {
+                               X509_STORE_CTX_cleanup(&xs_ctx);
+                               return 0;
+                               }
+                       }
+               X509_STORE_CTX_cleanup(&xs_ctx);
+               }
        /* Thawte special :-) */
-       if (s->ctx->extra_certs != NULL)
        for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
                {
                x=sk_X509_value(s->ctx->extra_certs,i);
-               n=i2d_X509(x,NULL);
-               if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
-                       {
-                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
-                       return(0);
-                       }
-               p=(unsigned char *)&(buf->data[l]);
-               l2n3(n,p);
-               i2d_X509(x,&p);
-               l+=n+3;
+               if (!dtls1_add_cert_to_buf(buf, &l, x))
+                       return 0;
                }
 
        l-= (3 + DTLS1_HM_HEADER_LENGTH);

diff --git a/ssl/s3_both.c b/ssl/s3_both.c
index 2ecfbb77cb1704bda84a57110a3256af1f568daa..399fa2c29808fa79cbf7a4b66a511c308bcd7a7a 100644 (file)
--- a/ssl/s3_both.c
+++ b/ssl/s3_both.c
@@ -264,15 +264,31 @@ int ssl3_send_change_cipher_spec(SSL *s, int a, int b)
        return(ssl3_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
        }
 
+static int ssl3_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
+       {
+               int n;
+               unsigned char *p;
+
+               n=i2d_X509(x,NULL);
+               if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
+                       {
+                               SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
+                               return(-1);
+                       }
+               p=(unsigned char *)&(buf->data[*l]);
+               l2n3(n,p);
+               i2d_X509(x,&p);
+               *l+=n+3;
+
+               return(0);
+       }
+
 unsigned long ssl3_output_cert_chain(SSL *s, X509 *x)
        {
        unsigned char *p;
-       int n,i;
+       int i;
        unsigned long l=7;
        BUF_MEM *buf;
-       X509_STORE_CTX xs_ctx;
-       X509_OBJECT obj;
-
        int no_chain;
 
        if ((s->mode & SSL_MODE_NO_AUTO_CHAIN) || s->ctx->extra_certs)
@@ -289,58 +305,40 @@ unsigned long ssl3_output_cert_chain(SSL *s, X509 *x)
                }
        if (x != NULL)
                {
-               if(!no_chain && !X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
+               if (no_chain)
                        {
-                       SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
-                       return(0);
+                       if (ssl3_add_cert_to_buf(buf, &l, x))
+                               return(0);
                        }
-
-               for (;;)
+               else
                        {
-                       n=i2d_X509(x,NULL);
-                       if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
+                       X509_STORE_CTX xs_ctx;
+
+                       if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
                                {
-                               SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
+                               SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
                                return(0);
                                }
-                       p=(unsigned char *)&(buf->data[l]);
-                       l2n3(n,p);
-                       i2d_X509(x,&p);
-                       l+=n+3;
-
-                       if (no_chain)
-                               break;
-
-                       if (X509_NAME_cmp(X509_get_subject_name(x),
-                               X509_get_issuer_name(x)) == 0) break;
-
-                       i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
-                               X509_get_issuer_name(x),&obj);
-                       if (i <= 0) break;
-                       x=obj.data.x509;
-                       /* Count is one too high since the X509_STORE_get uped the
-                        * ref count */
-                       X509_free(x);
-                       }
-               if (!no_chain)
+                       X509_verify_cert(&xs_ctx);
+                       for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
+                               {
+                               x = sk_X509_value(xs_ctx.chain, i);
+
+                               if (ssl3_add_cert_to_buf(buf, &l, x))
+                                       {
+                                       X509_STORE_CTX_cleanup(&xs_ctx);
+                                       return 0;
+                                       }
+                               }
                        X509_STORE_CTX_cleanup(&xs_ctx);
+                       }
                }
-
        /* Thawte special :-) */
-       if (s->ctx->extra_certs != NULL)
        for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
                {
                x=sk_X509_value(s->ctx->extra_certs,i);
-               n=i2d_X509(x,NULL);
-               if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
-                       {
-                       SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
+               if (ssl3_add_cert_to_buf(buf, &l, x))
                        return(0);
-                       }
-               p=(unsigned char *)&(buf->data[l]);
-               l2n3(n,p);
-               i2d_X509(x,&p);
-               l+=n+3;
                }
 
        l-=7;