Added restrictions on the use of proxy certificates, as they may pose

[openssl.git] / crypto / x509 / x509_vfy.c

diff --git a/crypto/x509/x509_vfy.c b/crypto/x509/x509_vfy.c
index c6c83ad72f915a8fa040a6323350e4822bb448d3..3da2490fea29934f4acb37e8355b31c7b48c3bd8 100644 (file)
--- a/crypto/x509/x509_vfy.c
+++ b/crypto/x509/x509_vfy.c
@@ -102,7 +102,7 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
        X509_VERIFY_PARAM *param = ctx->param;
        int depth,i,ok=0;
        int num;
-       int (*cb)();
+       int (*cb)(int ok,X509_STORE_CTX *ctx);
        STACK_OF(X509) *sktmp=NULL;
        if (ctx->cert == NULL)
                {
@@ -388,8 +388,10 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
 #else
        int i, ok=0, must_be_ca;
        X509 *x;
-       int (*cb)();
+       int (*cb)(int ok,X509_STORE_CTX *ctx);
+       int proxy_path_length = 0;
        cb=ctx->verify_cb;
+       int allow_proxy_certs = !!(ctx->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
 
        /* must_be_ca can have 1 of 3 values:
           -1: we accept both CA and non-CA certificates, to allow direct
@@ -400,6 +402,12 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
               all certificates in the chain except the leaf certificate.
        */
        must_be_ca = -1;
+
+       /* A hack to keep people who don't want to modify their software
+          happy */
+       if (getenv("OPENSSL_ALLOW_PROXY_CERTS"))
+               allow_proxy_certs = 1;
+
        /* Check all untrusted certificates */
        for (i = 0; i < ctx->last_untrusted; i++)
                {
@@ -414,6 +422,14 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
                        ok=cb(0,ctx);
                        if (!ok) goto end;
                        }
+               if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY))
+                       {
+                       ctx->error = X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED;
+                       ctx->error_depth = i;
+                       ctx->current_cert = x;
+                       ok=cb(0,ctx);
+                       if (!ok) goto end;
+                       }
                ret = X509_check_ca(x);
                switch(must_be_ca)
                        {
@@ -472,7 +488,7 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
                        }
                /* Check pathlen */
                if ((i > 1) && (x->ex_pathlen != -1)
-                          && (i > (x->ex_pathlen + 1)))
+                          && (i > (x->ex_pathlen + proxy_path_length + 1)))
                        {
                        ctx->error = X509_V_ERR_PATH_LENGTH_EXCEEDED;
                        ctx->error_depth = i;
@@ -480,8 +496,26 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
                        ok=cb(0,ctx);
                        if (!ok) goto end;
                        }
-               /* The next certificate must be a CA */
-               must_be_ca = 1;
+               /* If this certificate is a proxy certificate, the next
+                  certificate must be another proxy certificate or a EE
+                  certificate.  If not, the next certificate must be a
+                  CA certificate.  */
+               if (x->ex_flags & EXFLAG_PROXY)
+                       {
+                       if (x->ex_pcpathlen != -1 && i > x->ex_pcpathlen)
+                               {
+                               ctx->error =
+                                       X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED;
+                               ctx->error_depth = i;
+                               ctx->current_cert = x;
+                               ok=cb(0,ctx);
+                               if (!ok) goto end;
+                               }
+                       proxy_path_length++;
+                       must_be_ca = 0;
+                       }
+               else
+                       must_be_ca = 1;
                }
        ok = 1;
  end:
@@ -496,7 +530,7 @@ static int check_trust(X509_STORE_CTX *ctx)
 #else
        int i, ok;
        X509 *x;
-       int (*cb)();
+       int (*cb)(int ok,X509_STORE_CTX *ctx);
        cb=ctx->verify_cb;
 /* For now just check the last certificate in the chain */
        i = sk_X509_num(ctx->chain) - 1;
@@ -906,7 +940,7 @@ static int internal_verify(X509_STORE_CTX *ctx)
        int ok=0,n;
        X509 *xs,*xi;
        EVP_PKEY *pkey=NULL;
-       int (*cb)();
+       int (*cb)(int ok,X509_STORE_CTX *ctx);
 
        cb=ctx->verify_cb;
 
@@ -975,6 +1009,7 @@ static int internal_verify(X509_STORE_CTX *ctx)
                        goto end;
 
                /* The last error (if any) is still in the error value */
+               ctx->current_issuer=xi;
                ctx->current_cert=xs;
                ok=(*cb)(1,ctx);
                if (!ok) goto end;