Enable message names for TLS 1.1, 1.2 with -msg.
[openssl.git] / apps / s_cb.c
index 9a35d46adc2866fabf00de08aad02f2e44988336..550fa6cc33b5df0014cc196e6e332884f211d843 100644 (file)
@@ -56,7 +56,7 @@
  * [including the GNU Public Licence.]
  */
 /* ====================================================================
- * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
 #undef NON_MAIN
 #undef USE_SOCKETS
 #include <openssl/err.h>
+#include <openssl/rand.h>
 #include <openssl/x509.h>
 #include <openssl/ssl.h>
 #include "s_apps.h"
 
+#define        COOKIE_SECRET_LENGTH    16
+
 int verify_depth=0;
 int verify_error=X509_V_OK;
+int verify_return_error=0;
+unsigned char cookie_secret[COOKIE_SECRET_LENGTH];
+int cookie_initialized=0;
 
 int MS_CALLBACK verify_callback(int ok, X509_STORE_CTX *ctx)
        {
-       char buf[256];
        X509 *err_cert;
        int err,depth;
 
@@ -134,15 +139,23 @@ int MS_CALLBACK verify_callback(int ok, X509_STORE_CTX *ctx)
        err=    X509_STORE_CTX_get_error(ctx);
        depth=  X509_STORE_CTX_get_error_depth(ctx);
 
-       X509_NAME_oneline(X509_get_subject_name(err_cert),buf,sizeof buf);
-       BIO_printf(bio_err,"depth=%d %s\n",depth,buf);
+       BIO_printf(bio_err,"depth=%d ",depth);
+       if (err_cert)
+               {
+               X509_NAME_print_ex(bio_err, X509_get_subject_name(err_cert),
+                                       0, XN_FLAG_ONELINE);
+               BIO_puts(bio_err, "\n");
+               }
+       else
+               BIO_puts(bio_err, "<no cert>\n");
        if (!ok)
                {
                BIO_printf(bio_err,"verify error:num=%d:%s\n",err,
                        X509_verify_cert_error_string(err));
                if (verify_depth >= depth)
                        {
-                       ok=1;
+                       if (!verify_return_error)
+                               ok=1;
                        verify_error=X509_V_OK;
                        }
                else
@@ -151,25 +164,33 @@ int MS_CALLBACK verify_callback(int ok, X509_STORE_CTX *ctx)
                        verify_error=X509_V_ERR_CERT_CHAIN_TOO_LONG;
                        }
                }
-       switch (ctx->error)
+       switch (err)
                {
        case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
-               X509_NAME_oneline(X509_get_issuer_name(ctx->current_cert),buf,sizeof buf);
-               BIO_printf(bio_err,"issuer= %s\n",buf);
+               BIO_puts(bio_err,"issuer= ");
+               X509_NAME_print_ex(bio_err, X509_get_issuer_name(err_cert),
+                                       0, XN_FLAG_ONELINE);
+               BIO_puts(bio_err, "\n");
                break;
        case X509_V_ERR_CERT_NOT_YET_VALID:
        case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
                BIO_printf(bio_err,"notBefore=");
-               ASN1_TIME_print(bio_err,X509_get_notBefore(ctx->current_cert));
+               ASN1_TIME_print(bio_err,X509_get_notBefore(err_cert));
                BIO_printf(bio_err,"\n");
                break;
        case X509_V_ERR_CERT_HAS_EXPIRED:
        case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
                BIO_printf(bio_err,"notAfter=");
-               ASN1_TIME_print(bio_err,X509_get_notAfter(ctx->current_cert));
+               ASN1_TIME_print(bio_err,X509_get_notAfter(err_cert));
                BIO_printf(bio_err,"\n");
                break;
+       case X509_V_ERR_NO_EXPLICIT_POLICY:
+               policies_print(bio_err, ctx);
+               break;
                }
+       if (err == X509_V_OK && ok == 2)
+               policies_print(bio_err, ctx);
+
        BIO_printf(bio_err,"verify return:%d\n",ok);
        return(ok);
        }
@@ -216,8 +237,8 @@ int set_cert_stuff(SSL_CTX *ctx, char *cert_file, char *key_file)
 
                /* If we are using DSA, we can copy the parameters from
                 * the private key */
-               
-               
+
+
                /* Now we know that a key and cert have been set against
                 * the SSL context */
                if (!SSL_CTX_check_private_key(ctx))
@@ -229,9 +250,10 @@ int set_cert_stuff(SSL_CTX *ctx, char *cert_file, char *key_file)
        return(1);
        }
 
-int set_cert_key_stuff(SSL_CTX *ctx, X509 *cert, EVP_PKEY *key)
+int set_cert_key_stuff(SSL_CTX *ctx, X509 *cert, EVP_PKEY *key,
+                      STACK_OF(X509) *chain, int build_chain)
        {
-       if (cert ==  NULL)
+       if (cert == NULL)
                return 1;
        if (SSL_CTX_use_certificate(ctx,cert) <= 0)
                {
@@ -239,26 +261,211 @@ int set_cert_key_stuff(SSL_CTX *ctx, X509 *cert, EVP_PKEY *key)
                ERR_print_errors(bio_err);
                return 0;
                }
-       if (SSL_CTX_use_PrivateKey(ctx,key) <= 0)
+
+       if (SSL_CTX_use_PrivateKey(ctx,key) <= 0)
+               {
+               BIO_printf(bio_err,"error setting private key\n");
+               ERR_print_errors(bio_err);
+               return 0;
+               }
+                
+       /* Now we know that a key and cert have been set against
+        * the SSL context */
+       if (!SSL_CTX_check_private_key(ctx))
                {
-               BIO_printf(bio_err,"error setting private key\n");
+               BIO_printf(bio_err,"Private key does not match the certificate public key\n");
+               return 0;
+               }
+       if (chain && !SSL_CTX_set1_chain(ctx, chain))
+               {
+               BIO_printf(bio_err,"error setting certificate chain\n");
                ERR_print_errors(bio_err);
                return 0;
                }
-
-               
-               /* Now we know that a key and cert have been set against
-                * the SSL context */
-       if (!SSL_CTX_check_private_key(ctx))
+       if (!chain && build_chain && !SSL_CTX_build_cert_chain(ctx, 0))
                {
-               BIO_printf(bio_err,"Private key does not match the certificate public key\n");
+               BIO_printf(bio_err,"error building certificate chain\n");
+               ERR_print_errors(bio_err);
                return 0;
                }
+               
+       return 1;
+       }
+
+static void ssl_print_client_cert_types(BIO *bio, SSL *s)
+       {
+       const unsigned char *p;
+       int i;
+       int cert_type_num = SSL_get0_certificate_types(s, &p);
+       if (!cert_type_num)
+               return;
+       BIO_puts(bio, "Client Certificate Types: ");
+       for (i = 0; i < cert_type_num; i++)
+               {
+               unsigned char cert_type = p[i];
+               char *cname;
+               switch(cert_type)
+                       {
+               case TLS_CT_RSA_SIGN:
+                       cname = "RSA sign";
+                       break;
+
+               case TLS_CT_DSS_SIGN:
+                       cname = "DSA sign";
+                       break;
+
+               case TLS_CT_RSA_FIXED_DH:
+                       cname = "RSA fixed DH";
+                       break;
+
+               case TLS_CT_DSS_FIXED_DH:
+                       cname = "DSS fixed DH";
+                       break;
+
+               case TLS_CT_ECDSA_SIGN:
+                       cname = "ECDSA sign";
+                       break;
+
+               case TLS_CT_RSA_FIXED_ECDH:
+                       cname = "RSA fixed ECDH";
+                       break;
+
+               case TLS_CT_ECDSA_FIXED_ECDH:
+                       cname = "ECDSA fixed ECDH";
+                       break;
+
+               case TLS_CT_GOST94_SIGN:
+                       cname = "GOST94 Sign";
+                       break;
+
+               case TLS_CT_GOST01_SIGN:
+                       cname = "GOST01 Sign";
+                       break;
+
+               default:
+                        cname = NULL;
+                       }
+
+               if (i)
+                       BIO_puts(bio, ", ");
+
+               if (cname)
+                       BIO_puts(bio, cname);
+               else
+                       BIO_printf(bio, "UNKNOWN (%d),", cert_type);
+               }
+       BIO_puts(bio, "\n");
+       }
+
+static int do_print_sigalgs(BIO *out, SSL *s, int shared)
+       {
+       int i, nsig, client;
+       client = SSL_is_server(s) ? 0 : 1;
+       if (shared)
+               nsig = SSL_get_shared_sigalgs(s, -1, NULL, NULL, NULL,
+                                                       NULL, NULL);
+       else
+               nsig = SSL_get_sigalgs(s, -1, NULL, NULL, NULL, NULL, NULL);
+       if (nsig == 0)
+               return 1;
+
+       if (shared)
+               BIO_puts(out, "Shared ");
+
+       if (client)
+               BIO_puts(out, "Requested ");
+       BIO_puts(out, "Signature Algorithms: ");
+       for (i = 0; i < nsig; i++)
+               {
+               int hash_nid, sign_nid;
+               unsigned char rhash, rsign;
+               const char *sstr = NULL;
+               if (shared)
+                       SSL_get_shared_sigalgs(s, i, &sign_nid, &hash_nid, NULL,
+                                                       &rsign, &rhash);
+               else
+                       SSL_get_sigalgs(s, i, &sign_nid, &hash_nid, NULL,
+                                                       &rsign, &rhash);
+               if (i)
+                       BIO_puts(out, ":");
+               if (sign_nid == EVP_PKEY_RSA)
+                       sstr = "RSA";
+               else if(sign_nid == EVP_PKEY_DSA)
+                       sstr = "DSA";
+               else if(sign_nid == EVP_PKEY_EC)
+                       sstr = "ECDSA";
+               if (sstr)
+                       BIO_printf(out,"%s+", sstr);
+               else
+                       BIO_printf(out,"0x%02X+", (int)rsign);
+               if (hash_nid != NID_undef)
+                       BIO_printf(out, "%s", OBJ_nid2sn(hash_nid));
+               else
+                       BIO_printf(out,"0x%02X", (int)rhash);
+               }
+       BIO_puts(out, "\n");
        return 1;
        }
 
+int ssl_print_sigalgs(BIO *out, SSL *s)
+       {
+       if (!SSL_is_server(s))
+               ssl_print_client_cert_types(out, s);
+       do_print_sigalgs(out, s, 0);
+       do_print_sigalgs(out, s, 1);
+       return 1;
+       }
+
+int ssl_print_curves(BIO *out, SSL *s)
+       {
+       int i, ncurves, *curves, nid;
+       const char *cname;
+       ncurves = SSL_get1_curves(s, NULL);
+       if (ncurves <= 0)
+               return 1;
+       curves = OPENSSL_malloc(ncurves * sizeof(int));
+       SSL_get1_curves(s, curves);
+
+       BIO_puts(out, "Supported Elliptic Curves: ");
+       for (i = 0; i < ncurves; i++)
+               {
+               if (i)
+                       BIO_puts(out, ":");
+               nid = curves[i];
+               /* If unrecognised print out hex version */
+               if (nid & TLSEXT_nid_unknown)
+                       BIO_printf(out, "0x%04X", nid & 0xFFFF);
+               else
+                       {
+                       /* Use NIST name for curve if it exists */
+                       cname = EC_curve_nid2nist(nid);
+                       if (!cname)
+                               cname = OBJ_nid2sn(nid);
+                       BIO_printf(out, "%s", cname);
+                       }
+               }
+       BIO_puts(out, "\nShared Elliptic curves: ");
+       OPENSSL_free(curves);
+       ncurves = SSL_get_shared_curve(s, -1);
+       for (i = 0; i < ncurves; i++)
+               {
+               if (i)
+                       BIO_puts(out, ":");
+               nid = SSL_get_shared_curve(s, i);
+               cname = EC_curve_nid2nist(nid);
+               if (!cname)
+                       cname = OBJ_nid2sn(nid);
+               BIO_printf(out, "%s", cname);
+               }
+       if (ncurves == 0)
+               BIO_puts(out, "NONE");
+       BIO_puts(out, "\n");
+       return 1;
+       }
+
+
 long MS_CALLBACK bio_dump_callback(BIO *bio, int cmd, const char *argp,
-       int argi, long argl, long ret)
+                                  int argi, long argl, long ret)
        {
        BIO *out;
 
@@ -267,15 +474,15 @@ long MS_CALLBACK bio_dump_callback(BIO *bio, int cmd, const char *argp,
 
        if (cmd == (BIO_CB_READ|BIO_CB_RETURN))
                {
-               BIO_printf(out,"read from %p [%p] (%d bytes => %ld (0x%lX))\n",
-                       (void *)bio,argp,argi,ret,ret);
+               BIO_printf(out,"read from %p [%p] (%lu bytes => %ld (0x%lX))\n",
+                       (void *)bio,argp,(unsigned long)argi,ret,ret);
                BIO_dump(out,argp,(int)ret);
                return(ret);
                }
        else if (cmd == (BIO_CB_WRITE|BIO_CB_RETURN))
                {
-               BIO_printf(out,"write to %p [%p] (%d bytes => %ld (0x%lX))\n",
-                       (void *)bio,argp,argi,ret,ret);
+               BIO_printf(out,"write to %p [%p] (%lu bytes => %ld (0x%lX))\n",
+                       (void *)bio,argp,(unsigned long)argi,ret,ret);
                BIO_dump(out,argp,(int)ret);
                }
        return(ret);
@@ -336,6 +543,18 @@ void MS_CALLBACK msg_cb(int write_p, int version, int content_type, const void *
        case TLS1_VERSION:
                str_version = "TLS 1.0 ";
                break;
+       case TLS1_1_VERSION:
+               str_version = "TLS 1.1 ";
+               break;
+       case TLS1_2_VERSION:
+               str_version = "TLS 1.2 ";
+               break;
+       case DTLS1_VERSION:
+               str_version = "DTLS 1.0 ";
+               break;
+       case DTLS1_BAD_VER:
+               str_version = "DTLS 1.0 (bad) ";
+               break;
        default:
                str_version = "???";
                }
@@ -401,7 +620,12 @@ void MS_CALLBACK msg_cb(int write_p, int version, int content_type, const void *
                        }
                }
 
-       if (version == SSL3_VERSION || version == TLS1_VERSION)
+       if (version == SSL3_VERSION ||
+           version == TLS1_VERSION ||
+           version == TLS1_1_VERSION ||
+           version == TLS1_2_VERSION ||
+           version == DTLS1_VERSION ||
+           version == DTLS1_BAD_VER)
                {
                switch (content_type)
                        {
@@ -504,6 +728,24 @@ void MS_CALLBACK msg_cb(int write_p, int version, int content_type, const void *
                                case 100:
                                        str_details2 = " no_renegotiation";
                                        break;
+                               case 110:
+                                       str_details2 = " unsupported_extension";
+                                       break;
+                               case 111:
+                                       str_details2 = " certificate_unobtainable";
+                                       break;
+                               case 112:
+                                       str_details2 = " unrecognized_name";
+                                       break;
+                               case 113:
+                                       str_details2 = " bad_certificate_status_response";
+                                       break;
+                               case 114:
+                                       str_details2 = " bad_certificate_hash_value";
+                                       break;
+                               case 115:
+                                       str_details2 = " unknown_psk_identity";
+                                       break;
                                        }
                                }
                        }
@@ -525,6 +767,9 @@ void MS_CALLBACK msg_cb(int write_p, int version, int content_type, const void *
                                case 2:
                                        str_details1 = ", ServerHello";
                                        break;
+                               case 3:
+                                       str_details1 = ", HelloVerifyRequest";
+                                       break;
                                case 11:
                                        str_details1 = ", Certificate";
                                        break;
@@ -549,6 +794,26 @@ void MS_CALLBACK msg_cb(int write_p, int version, int content_type, const void *
                                        }
                                }
                        }
+
+#ifndef OPENSSL_NO_HEARTBEATS
+               if (content_type == 24) /* Heartbeat */
+                       {
+                       str_details1 = ", Heartbeat";
+                       
+                       if (len > 0)
+                               {
+                               switch (((const unsigned char*)buf)[0])
+                                       {
+                               case 1:
+                                       str_details1 = ", HeartbeatRequest";
+                                       break;
+                               case 2:
+                                       str_details1 = ", HeartbeatResponse";
+                                       break;
+                                       }
+                               }
+                       }
+#endif
                }
 
        BIO_printf(bio, "%s %s%s [length %04lx]%s%s\n", str_write_p, str_version, str_content_type, (unsigned long)len, str_details1, str_details2);
@@ -573,5 +838,587 @@ void MS_CALLBACK msg_cb(int write_p, int version, int content_type, const void *
                        BIO_printf(bio, " ...");
                BIO_printf(bio, "\n");
                }
-       BIO_flush(bio);
+       (void)BIO_flush(bio);
+       }
+
+void MS_CALLBACK tlsext_cb(SSL *s, int client_server, int type,
+                                       unsigned char *data, int len,
+                                       void *arg)
+       {
+       BIO *bio = arg;
+       char *extname;
+
+       switch(type)
+               {
+               case TLSEXT_TYPE_server_name:
+               extname = "server name";
+               break;
+
+               case TLSEXT_TYPE_max_fragment_length:
+               extname = "max fragment length";
+               break;
+
+               case TLSEXT_TYPE_client_certificate_url:
+               extname = "client certificate URL";
+               break;
+
+               case TLSEXT_TYPE_trusted_ca_keys:
+               extname = "trusted CA keys";
+               break;
+
+               case TLSEXT_TYPE_truncated_hmac:
+               extname = "truncated HMAC";
+               break;
+
+               case TLSEXT_TYPE_status_request:
+               extname = "status request";
+               break;
+
+               case TLSEXT_TYPE_user_mapping:
+               extname = "user mapping";
+               break;
+
+               case TLSEXT_TYPE_client_authz:
+               extname = "client authz";
+               break;
+
+               case TLSEXT_TYPE_server_authz:
+               extname = "server authz";
+               break;
+
+               case TLSEXT_TYPE_cert_type:
+               extname = "cert type";
+               break;
+
+               case TLSEXT_TYPE_elliptic_curves:
+               extname = "elliptic curves";
+               break;
+
+               case TLSEXT_TYPE_ec_point_formats:
+               extname = "EC point formats";
+               break;
+
+               case TLSEXT_TYPE_srp:
+               extname = "SRP";
+               break;
+
+               case TLSEXT_TYPE_signature_algorithms:
+               extname = "signature algorithms";
+               break;
+
+               case TLSEXT_TYPE_use_srtp:
+               extname = "use SRTP";
+               break;
+
+               case TLSEXT_TYPE_heartbeat:
+               extname = "heartbeat";
+               break;
+
+               case TLSEXT_TYPE_session_ticket:
+               extname = "session ticket";
+               break;
+
+               case TLSEXT_TYPE_renegotiate: 
+               extname = "renegotiation info";
+               break;
+
+#ifdef TLSEXT_TYPE_opaque_prf_input
+               case TLSEXT_TYPE_opaque_prf_input:
+               extname = "opaque PRF input";
+               break;
+#endif
+#ifdef TLSEXT_TYPE_next_proto_neg
+               case TLSEXT_TYPE_next_proto_neg:
+               extname = "next protocol";
+               break;
+#endif
+
+               default:
+               extname = "unknown";
+               break;
+
+               }
+       
+       BIO_printf(bio, "TLS %s extension \"%s\" (id=%d), len=%d\n",
+                       client_server ? "server": "client",
+                       extname, type, len);
+       BIO_dump(bio, (char *)data, len);
+       (void)BIO_flush(bio);
        }
+
+int MS_CALLBACK generate_cookie_callback(SSL *ssl, unsigned char *cookie, unsigned int *cookie_len)
+       {
+       unsigned char *buffer, result[EVP_MAX_MD_SIZE];
+       unsigned int length, resultlength;
+       union {
+               struct sockaddr sa;
+               struct sockaddr_in s4;
+#if OPENSSL_USE_IPV6
+               struct sockaddr_in6 s6;
+#endif
+       } peer;
+
+       /* Initialize a random secret */
+       if (!cookie_initialized)
+               {
+               if (!RAND_bytes(cookie_secret, COOKIE_SECRET_LENGTH))
+                       {
+                       BIO_printf(bio_err,"error setting random cookie secret\n");
+                       return 0;
+                       }
+               cookie_initialized = 1;
+               }
+
+       /* Read peer information */
+       (void)BIO_dgram_get_peer(SSL_get_rbio(ssl), &peer);
+
+       /* Create buffer with peer's address and port */
+       length = 0;
+       switch (peer.sa.sa_family)
+               {
+       case AF_INET:
+               length += sizeof(struct in_addr);
+               length += sizeof(peer.s4.sin_port);
+               break;
+#if OPENSSL_USE_IPV6
+       case AF_INET6:
+               length += sizeof(struct in6_addr);
+               length += sizeof(peer.s6.sin6_port);
+               break;
+#endif
+       default:
+               OPENSSL_assert(0);
+               break;
+               }
+       buffer = OPENSSL_malloc(length);
+
+       if (buffer == NULL)
+               {
+               BIO_printf(bio_err,"out of memory\n");
+               return 0;
+               }
+
+       switch (peer.sa.sa_family)
+               {
+       case AF_INET:
+               memcpy(buffer,
+                      &peer.s4.sin_port,
+                      sizeof(peer.s4.sin_port));
+               memcpy(buffer + sizeof(peer.s4.sin_port),
+                      &peer.s4.sin_addr,
+                      sizeof(struct in_addr));
+               break;
+#if OPENSSL_USE_IPV6
+       case AF_INET6:
+               memcpy(buffer,
+                      &peer.s6.sin6_port,
+                      sizeof(peer.s6.sin6_port));
+               memcpy(buffer + sizeof(peer.s6.sin6_port),
+                      &peer.s6.sin6_addr,
+                      sizeof(struct in6_addr));
+               break;
+#endif
+       default:
+               OPENSSL_assert(0);
+               break;
+               }
+
+       /* Calculate HMAC of buffer using the secret */
+       HMAC(EVP_sha1(), cookie_secret, COOKIE_SECRET_LENGTH,
+            buffer, length, result, &resultlength);
+       OPENSSL_free(buffer);
+
+       memcpy(cookie, result, resultlength);
+       *cookie_len = resultlength;
+
+       return 1;
+       }
+
+int MS_CALLBACK verify_cookie_callback(SSL *ssl, unsigned char *cookie, unsigned int cookie_len)
+       {
+       unsigned char *buffer, result[EVP_MAX_MD_SIZE];
+       unsigned int length, resultlength;
+       union {
+               struct sockaddr sa;
+               struct sockaddr_in s4;
+#if OPENSSL_USE_IPV6
+               struct sockaddr_in6 s6;
+#endif
+       } peer;
+
+       /* If secret isn't initialized yet, the cookie can't be valid */
+       if (!cookie_initialized)
+               return 0;
+
+       /* Read peer information */
+       (void)BIO_dgram_get_peer(SSL_get_rbio(ssl), &peer);
+
+       /* Create buffer with peer's address and port */
+       length = 0;
+       switch (peer.sa.sa_family)
+               {
+       case AF_INET:
+               length += sizeof(struct in_addr);
+               length += sizeof(peer.s4.sin_port);
+               break;
+#if OPENSSL_USE_IPV6
+       case AF_INET6:
+               length += sizeof(struct in6_addr);
+               length += sizeof(peer.s6.sin6_port);
+               break;
+#endif
+       default:
+               OPENSSL_assert(0);
+               break;
+               }
+       buffer = OPENSSL_malloc(length);
+       
+       if (buffer == NULL)
+               {
+               BIO_printf(bio_err,"out of memory\n");
+               return 0;
+               }
+
+       switch (peer.sa.sa_family)
+               {
+       case AF_INET:
+               memcpy(buffer,
+                      &peer.s4.sin_port,
+                      sizeof(peer.s4.sin_port));
+               memcpy(buffer + sizeof(peer.s4.sin_port),
+                      &peer.s4.sin_addr,
+                      sizeof(struct in_addr));
+               break;
+#if OPENSSL_USE_IPV6
+       case AF_INET6:
+               memcpy(buffer,
+                      &peer.s6.sin6_port,
+                      sizeof(peer.s6.sin6_port));
+               memcpy(buffer + sizeof(peer.s6.sin6_port),
+                      &peer.s6.sin6_addr,
+                      sizeof(struct in6_addr));
+               break;
+#endif
+       default:
+               OPENSSL_assert(0);
+               break;
+               }
+
+       /* Calculate HMAC of buffer using the secret */
+       HMAC(EVP_sha1(), cookie_secret, COOKIE_SECRET_LENGTH,
+            buffer, length, result, &resultlength);
+       OPENSSL_free(buffer);
+
+       if (cookie_len == resultlength && memcmp(result, cookie, resultlength) == 0)
+               return 1;
+
+       return 0;
+       }
+
+/* Example of extended certificate handling. Where the standard support
+ * of one certificate per algorithm is not sufficient an application
+ * can decide which certificate(s) to use at runtime based on whatever
+ * criteria it deems appropriate.
+ */
+
+/* Linked list of certificates, keys and chains */
+struct  ssl_excert_st
+       {
+       int certform;
+       const char *certfile;
+       int keyform;
+       const char *keyfile;
+       const char *chainfile;
+       X509 *cert;
+       EVP_PKEY *key;
+       STACK_OF(X509) *chain;
+       int build_chain;
+       struct ssl_excert_st *next, *prev;
+       };
+
+struct chain_flags
+       {
+       int flag;
+       const char *name;
+       };
+
+struct chain_flags chain_flags_list[] =
+       {
+               {CERT_PKEY_VALID, "Overall Validity"},
+               {CERT_PKEY_SIGN,  "Sign with EE key"},
+               {CERT_PKEY_EE_SIGNATURE, "EE signature"},
+               {CERT_PKEY_CA_SIGNATURE, "CA signature"},
+               {CERT_PKEY_EE_PARAM, "EE key parameters"},
+               {CERT_PKEY_CA_PARAM, "CA key parameters"},
+               {CERT_PKEY_EXPLICIT_SIGN,  "Explicity sign with EE key"},
+               {CERT_PKEY_ISSUER_NAME,  "Issuer Name"},
+               {CERT_PKEY_CERT_TYPE,  "Certificate Type"},
+               {0, NULL}
+       };
+
+
+static void print_chain_flags(BIO *out, int flags)
+       {
+       struct chain_flags *ctmp = chain_flags_list;
+       while(ctmp->name)
+               {
+               BIO_printf(out, "\t%s: %s\n", ctmp->name,
+                               flags & ctmp->flag ? "OK" : "NOT OK");
+               ctmp++;
+               }
+       }
+
+/* Very basic selection callback: just use any certificate chain
+ * reported as valid. More sophisticated could prioritise according
+ * to local policy.
+ */
+static int set_cert_cb(SSL *ssl, void *arg)
+       {
+       int i, rv;
+       SSL_EXCERT *exc = arg;
+       SSL_certs_clear(ssl);
+
+       if (!exc)
+               return 1;
+
+       /* Go to end of list and traverse backwards since we prepend
+        * newer entries this retains the original order.
+        */
+       while (exc->next)
+               exc = exc->next;
+
+       i = 0;  
+
+       while(exc)
+               {
+               i++;
+               rv = SSL_check_chain(ssl, exc->cert, exc->key, exc->chain);
+               BIO_printf(bio_err, "Checking cert chain %d:\nSubject: ", i);
+               X509_NAME_print_ex(bio_err, X509_get_subject_name(exc->cert), 0,
+                                                       XN_FLAG_ONELINE);
+               BIO_puts(bio_err, "\n");
+               
+               print_chain_flags(bio_err, rv);
+               if (rv & CERT_PKEY_VALID)
+                       {
+                       SSL_use_certificate(ssl, exc->cert);
+                       SSL_use_PrivateKey(ssl, exc->key);
+                       /* NB: we wouldn't normally do this as it is
+                        * not efficient building chains on each connection
+                        * better to cache the chain in advance.
+                        */
+                       if (exc->build_chain)
+                               {
+                               if (!SSL_build_cert_chain(ssl, 0))
+                                       return 0;
+                               }
+                       else if (exc->chain)
+                               SSL_set1_chain(ssl, exc->chain);
+                       }
+               exc = exc->prev;
+               }
+       return 1;
+       }
+
+void ssl_ctx_set_excert(SSL_CTX *ctx, SSL_EXCERT *exc)
+       {
+       SSL_CTX_set_cert_cb(ctx, set_cert_cb, exc);
+       }
+
+static int ssl_excert_prepend(SSL_EXCERT **pexc)
+       {
+       SSL_EXCERT *exc;
+       exc = OPENSSL_malloc(sizeof(SSL_EXCERT));
+       if (!exc)
+               return 0;
+       exc->certfile = NULL;
+       exc->keyfile = NULL;
+       exc->chainfile = NULL;
+       exc->cert = NULL;
+       exc->key = NULL;
+       exc->chain = NULL;
+       exc->prev = NULL;
+       exc->build_chain = 0;
+
+       exc->next = *pexc;
+       *pexc = exc;
+                       
+       if (exc->next)
+               {
+               exc->certform = exc->next->certform;
+               exc->keyform = exc->next->keyform;
+               exc->next->prev = exc;
+               }
+       else
+               {
+               exc->certform = FORMAT_PEM;
+               exc->keyform = FORMAT_PEM;
+               }
+       return 1;
+
+       }
+
+void ssl_excert_free(SSL_EXCERT *exc)
+       {
+       SSL_EXCERT *curr;
+       while (exc)
+               {
+               if (exc->cert)
+                       X509_free(exc->cert);
+               if (exc->key)
+                       EVP_PKEY_free(exc->key);
+               if (exc->chain)
+                       sk_X509_pop_free(exc->chain, X509_free);
+               curr = exc;
+               exc = exc->next;
+               OPENSSL_free(curr);
+               }
+       }
+
+int load_excert(SSL_EXCERT **pexc, BIO *err)
+       {
+       SSL_EXCERT *exc = *pexc;
+       if (!exc)
+               return 1;
+       /* If nothing in list, free and set to NULL */
+       if (!exc->certfile && !exc->next)
+               {
+               ssl_excert_free(exc);
+               *pexc = NULL;
+               return 1;
+               }
+       for(; exc; exc=exc->next)
+               {
+               if (!exc->certfile)
+                       {
+                       BIO_printf(err, "Missing filename\n");
+                       return 0;
+                       }
+               exc->cert = load_cert(err, exc->certfile, exc->certform,
+                                       NULL, NULL, "Server Certificate");
+               if (!exc->cert)
+                       return 0;
+               if (exc->keyfile)
+                       exc->keyfile = exc->certfile;
+               exc->key = load_key(err, exc->certfile, exc->certform, 0,
+                                       NULL, NULL, "Server Certificate");
+               if (!exc->key)
+                       return 0;
+               if (exc->chainfile)
+                       {
+                       exc->chain = load_certs(err,
+                                               exc->chainfile, FORMAT_PEM,
+                                               NULL, NULL,
+                                               "Server Chain");
+                       if (!exc->chainfile)
+                               return 0;
+                       }
+               }
+       return 1;
+       }
+               
+
+int args_excert(char ***pargs, int *pargc,
+                       int *badarg, BIO *err, SSL_EXCERT **pexc)
+       {
+       char *arg = **pargs, *argn = (*pargs)[1];
+       SSL_EXCERT *exc = *pexc;
+       int narg = 2;
+       if (!exc)
+               {
+               if (ssl_excert_prepend(&exc))
+                       *pexc = exc;
+               else
+                       {
+                       BIO_printf(err, "Error initialising xcert\n");
+                       *badarg = 1;
+                       goto err;
+                       }
+               }
+       if (strcmp(arg, "-xcert") == 0)
+               {
+               if (!argn)
+                       {
+                       *badarg = 1;
+                       return 1;
+                       }
+               if (exc->certfile && !ssl_excert_prepend(&exc))
+                       {
+                       BIO_printf(err, "Error adding xcert\n");
+                       *badarg = 1;
+                       goto err;
+                       }
+               exc->certfile = argn;
+               }
+       else if (strcmp(arg,"-xkey") == 0)
+               {
+               if (!argn)
+                       {
+                       *badarg = 1;
+                       return 1;
+                       }
+               if (exc->keyfile)
+                       {
+                       BIO_printf(err, "Key already specified\n");
+                       *badarg = 1;
+                       return 1;
+                       }
+               exc->keyfile = argn;
+               }
+       else if (strcmp(arg,"-xchain") == 0)
+               {
+               if (!argn)
+                       {
+                       *badarg = 1;
+                       return 1;
+                       }
+               if (exc->chainfile)
+                       {
+                       BIO_printf(err, "Chain already specified\n");
+                       *badarg = 1;
+                       return 1;
+                       }
+               exc->chainfile = argn;
+               }
+       else if (strcmp(arg,"-xchain_build") == 0)
+               {
+               narg = 1;
+               exc->build_chain = 1;
+               }
+       else if (strcmp(arg,"-xcertform") == 0)
+               {
+               if (!argn)
+                       {
+                       *badarg = 1;
+                       goto err;
+                       }
+               exc->certform = str2fmt(argn);
+               }
+       else if (strcmp(arg,"-xkeyform") == 0)
+               {
+               if (!argn)
+                       {
+                       *badarg = 1;
+                       goto err;
+                       }
+               exc->keyform = str2fmt(argn);
+               }
+       else
+               return 0;
+
+       (*pargs) += narg;
+
+       if (pargc)
+               *pargc -= narg;
+
+       *pexc = exc;
+
+       return 1;
+
+       err:
+       ERR_print_errors(err);
+       ssl_excert_free(exc);
+       *pexc = NULL;
+       return 1;
+       }
+