ssl-utils: load RSA keys based on their modulus+exponent

Load RSA private keys based on their public key instead of relying on
the user to specify a valid address and port mapping. This is more
reliable and prepares for simplification of the SSL Keys dialog.

After this change, the "address" part of the UAT dialog will be ignored
when loading the private key. The port+protocol mapping is still
imported, but should probably be removed too.

Change-Id: I4d7a2bfcf63d17e66e336ef770759f20510fc176
Reviewed-on: https://code.wireshark.org/review/10766
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

5 files changed, 152 insertions, 215 deletions

diff --git a/epan/dissectors/packet-dtls.c b/epan/dissectors/packet-dtls.c
index 579bb678f0..35948d5c66 100644
--- a/epan/dissectors/packet-dtls.c
+++ b/epan/dissectors/packet-dtls.c
@@ -1329,10 +1329,8 @@ dissect_dtls_handshake(tvbuff_t *tvb, packet_info *pinfo,
 
           case SSL_HND_CLIENT_HELLO:
             if (ssl) {
-                /* ClientHello is first packet so set direction and try to
-                 * find a private key matching the server port */
+                /* ClientHello is first packet so set direction */
                 ssl_set_server(session, &pinfo->dst, pinfo->ptype, pinfo->destport);
-                ssl_find_private_key(ssl, dtls_key_hash, dtls_associations, pinfo);
             }
             ssl_dissect_hnd_cli_hello(&dissect_dtls_hf, sub_tvb, pinfo,
                                       ssl_hand_tree, 0, length, session, ssl,
@@ -1357,7 +1355,8 @@ dissect_dtls_handshake(tvbuff_t *tvb, packet_info *pinfo,
             break;
 
           case SSL_HND_CERTIFICATE:
-            ssl_dissect_hnd_cert(&dissect_dtls_hf, sub_tvb, ssl_hand_tree, 0, pinfo, session, is_from_server);
+            ssl_dissect_hnd_cert(&dissect_dtls_hf, sub_tvb, ssl_hand_tree, 0,
+                pinfo, session, ssl, dtls_key_hash, is_from_server);
             break;
 
           case SSL_HND_SERVER_KEY_EXCHG:
diff --git a/epan/dissectors/packet-ssl-utils.c b/epan/dissectors/packet-ssl-utils.c
index 1dbc768f5a..39f5916018 100644
--- a/epan/dissectors/packet-ssl-utils.c
+++ b/epan/dissectors/packet-ssl-utils.c
@@ -48,6 +48,9 @@
 #include "packet-x509if.h"
 #include "packet-ssl-utils.h"
 #include "packet-ssl.h"
+#if defined(HAVE_LIBGNUTLS) && defined(HAVE_LIBGCRYPT)
+#include <gnutls/abstract.h>
+#endif
 
 /*
  * Lookup tables
@@ -3538,21 +3541,7 @@ ssl_privkey_to_sexp(gnutls_x509_privkey_t priv_key)
     gcry_error_t   gret;
     gcry_sexp_t    rsa_priv_key = NULL;
     gint           i;
-    int            ret;
-    size_t         buf_len;
-    unsigned char  buf_keyid[32];
-
-    gcry_mpi_t rsa_params[RSA_PARS];
-
-    buf_len = sizeof(buf_keyid);
-    ret = gnutls_x509_privkey_get_key_id(priv_key, 0, buf_keyid, &buf_len);
-    if (ret != 0) {
-        ssl_debug_printf( "gnutls_x509_privkey_get_key_id(ssl_pkey, 0, buf_keyid, &buf_len) - %s\n", gnutls_strerror(ret));
-    } else {
-        char* keyid = (char*)bytestring_to_str(NULL, buf_keyid, (int) buf_len, ':');
-        ssl_debug_printf( "Private key imported: KeyID %s\n", keyid);
-        wmem_free(NULL, keyid);
-    }
+    gcry_mpi_t     rsa_params[RSA_PARS];
 
     /* RSA get parameter */
     if (gnutls_x509_privkey_export_rsa_raw(priv_key,
@@ -3840,78 +3829,48 @@ ssl_private_key_free(gpointer key)
     gcry_sexp_release((gcry_sexp_t) key);
 }
 
-void
-ssl_find_private_key(SslDecryptSession *ssl_session, GHashTable *key_hash, GTree* associations, packet_info *pinfo) {
-    SslService dummy;
-    char       ip_addr_any[] = {0,0,0,0};
-    guint32    port    = 0;
-    gchar     *addr_string;
-    gcry_sexp_t private_key;
-
-    if (!ssl_session) {
-        return;
-    }
+static void
+ssl_find_private_key_by_pubkey(SslDecryptSession *ssl, GHashTable *key_hash,
+                               gnutls_datum_t *subjectPublicKeyInfo)
+{
+    gnutls_pubkey_t pubkey = NULL;
+    guchar key_id[20];
+    size_t key_id_len = sizeof(key_id);
+    int r;
 
-    /* we need to know which side of the conversation is speaking */
-    if (ssl_packet_from_server(&ssl_session->session, associations, pinfo)) {
-        dummy.addr = pinfo->src;
-        dummy.port = port = pinfo->srcport;
-    } else {
-        dummy.addr = pinfo->dst;
-        dummy.port = port = pinfo->destport;
+    if (!subjectPublicKeyInfo->size) {
+        ssl_debug_printf("%s: could not find SubjectPublicKeyInfo\n", G_STRFUNC);
+        return;
     }
-    addr_string = address_to_str(NULL, &dummy.addr);
-    ssl_debug_printf("ssl_find_private_key server %s:%u\n",
-                     addr_string, dummy.port);
-    wmem_free(NULL, addr_string);
 
-    if (g_hash_table_size(key_hash) == 0) {
-        ssl_debug_printf("ssl_find_private_key: no keys found\n");
+    r = gnutls_pubkey_init(&pubkey);
+    if (r < 0) {
+        ssl_debug_printf("%s: failed to init pubkey: %s\n",
+                G_STRFUNC, gnutls_strerror(r));
         return;
-    } else {
-        ssl_debug_printf("ssl_find_private_key: testing %i keys\n",
-            g_hash_table_size(key_hash));
     }
 
-    /* try to retrieve private key for this service. Do it now 'cause pinfo
-     * is not always available
-     * Note that with HAVE_LIBGNUTLS undefined private_key is allways 0
-     * and thus decryption never engaged*/
-
-
-    ssl_session->private_key = 0;
-    private_key = (gcry_sexp_t) g_hash_table_lookup(key_hash, &dummy);
-
-    if (!private_key) {
-        ssl_debug_printf("ssl_find_private_key can't find private key for this server! Try it again with universal port 0\n");
-
-        dummy.port = 0;
-        private_key = (gcry_sexp_t) g_hash_table_lookup(key_hash, &dummy);
+    r = gnutls_pubkey_import(pubkey, subjectPublicKeyInfo, GNUTLS_X509_FMT_DER);
+    if (r < 0) {
+        ssl_debug_printf("%s: failed to import pubkey from handshake: %s\n",
+                G_STRFUNC, gnutls_strerror(r));
+        goto end;
     }
 
-    if (!private_key) {
-        ssl_debug_printf("ssl_find_private_key can't find private key for this server (universal port)! Try it again with universal address 0.0.0.0\n");
-
-        dummy.addr.type = AT_IPv4;
-        dummy.addr.len = 4;
-        dummy.addr.data = ip_addr_any;
-
-        dummy.port = port;
-        private_key = (gcry_sexp_t) g_hash_table_lookup(key_hash, &dummy);
+    /* Generate a 20-byte SHA-1 hash. */
+    r = gnutls_pubkey_get_key_id(pubkey, 0, key_id, &key_id_len);
+    if (r < 0) {
+        ssl_debug_printf("%s: failed to extract key id from pubkey: %s\n",
+                G_STRFUNC, gnutls_strerror(r));
+        goto end;
     }
 
-    if (!private_key) {
-        ssl_debug_printf("ssl_find_private_key can't find private key for this server! Try it again with universal address 0.0.0.0 and universal port 0\n");
-
-        dummy.port = 0;
-        private_key = (gcry_sexp_t) g_hash_table_lookup(key_hash, &dummy);
-    }
+    ssl_print_data("lookup(KeyID)", key_id, key_id_len);
+    ssl->private_key = (gcry_sexp_t)g_hash_table_lookup(key_hash, key_id);
+    ssl_debug_printf("%s: lookup result: %p\n", G_STRFUNC, (void *) ssl->private_key);
 
-    if (!private_key) {
-        ssl_debug_printf("ssl_find_private_key can't find any private key!\n");
-    } else {
-        ssl_session->private_key = private_key;
-    }
+end:
+    gnutls_pubkey_deinit(pubkey);
 }
 
 void
@@ -3932,11 +3891,6 @@ ssl_private_key_free(gpointer key _U_)
 {
 }
 
-void
-ssl_find_private_key(SslDecryptSession *ssl_session _U_, GHashTable *key_hash _U_, GTree* associations _U_, packet_info *pinfo _U_)
-{
-}
-
 int
 ssl_find_cipher(int num,SslCipherSuite* cs)
 {
@@ -4116,36 +4070,23 @@ ssl_hash  (gconstpointer v)
     return hash;
 }
 
-gint
+gboolean
 ssl_private_key_equal (gconstpointer v, gconstpointer v2)
 {
-    const SslService *val1;
-    const SslService *val2;
-    val1 = (const SslService *)v;
-    val2 = (const SslService *)v2;
-
-    if ((val1->port == val2->port) &&
-        ! CMP_ADDRESS(&val1->addr, &val2->addr)) {
-        return 1;
-    }
-    return 0;
+    /* key ID length (SHA-1 hash, per GNUTLS_KEYID_USE_SHA1) */
+    return !memcmp(v, v2, 20);
 }
 
 guint
-ssl_private_key_hash  (gconstpointer v)
+ssl_private_key_hash (gconstpointer v)
 {
-    const SslService *key;
-    guint        l, hash, len ;
-    const guint8 *cur;
-
-    key  = (const SslService *)v;
-    hash = key->port;
-    len  = key->addr.len;
-    hash |= len << 16;
-    cur  = (const guint8 *) key->addr.data;
+    guint        l, hash = 0;
+    const guint8 *cur = (const guint8 *)v;
 
-    for (l=4; (l<len); l+=4, cur+=4)
-        hash = hash ^ pntoh32(cur);
+    /* The public key' SHA-1 hash (which maps to a private key) has a uniform
+     * distribution, hence simply xor'ing them should be sufficient. */
+    for (l = 0; l < 20; l += 4, cur += 4)
+        hash ^= pntoh32(cur);
 
     return hash;
 }
@@ -4384,14 +4325,12 @@ ssl_common_cleanup(ssl_master_key_map_t *mk_map, FILE **ssl_keylog_file,
 void
 ssl_parse_key_list(const ssldecrypt_assoc_t *uats, GHashTable *key_hash, GTree* associations, dissector_handle_t handle, gboolean tcp)
 {
-    SslService*        service;
     gnutls_x509_privkey_t priv_key;
     gcry_sexp_t        private_key;
     FILE*              fp     = NULL;
-    guint32            addr_data[4];
-    int                addr_len, at;
-    address_type addr_type[2] = { AT_IPv4, AT_IPv6 };
-    gchar*             address_string;
+    int                ret;
+    size_t             key_id_len = 20;
+    guchar            *key_id = NULL;
 
     /* try to load keys file first */
     fp = ws_fopen(uats->keyfile, "rb");
@@ -4400,87 +4339,53 @@ ssl_parse_key_list(const ssldecrypt_assoc_t *uats, GHashTable *key_hash, GTree*
         return;
     }
 
-    for (at = 0; at < 2; at++) {
-        memset(addr_data, 0, sizeof(addr_data));
-        addr_len = 0;
-
-        /* any: IPv4 or IPv6 wildcard */
-        /* anyipv4: IPv4 wildcard */
-        /* anyipv6: IPv6 wildcard */
-
-        if(addr_type[at] == AT_IPv4) {
-            if (strcmp(uats->ipaddr, "any") == 0 || strcmp(uats->ipaddr, "anyipv4") == 0 ||
-                    get_host_ipaddr(uats->ipaddr, &addr_data[0])) {
-                addr_len = 4;
-            }
-        } else { /* AT_IPv6 */
-            if(strcmp(uats->ipaddr, "any") == 0 || strcmp(uats->ipaddr, "anyipv6") == 0 ||
-                    get_host_ipaddr6(uats->ipaddr, (struct e_in6_addr *) addr_data)) {
-                addr_len = 16;
-            }
-        }
-
-        if (! addr_len) {
-            continue;
-        }
-
-        /* reset the data pointer for the second iteration */
-        rewind(fp);
-
-        if ((gint)strlen(uats->password) == 0) {
-            priv_key = ssl_load_key(fp);
-        } else {
-            char *err = NULL;
-            priv_key = ssl_load_pkcs12(fp, uats->password, &err);
-            if (err) {
-                report_failure("%s\n", err);
-                g_free(err);
-            }
-        }
-
-        if (!priv_key) {
-            report_failure("Can't load private key from %s\n", uats->keyfile);
-            break;
-        }
-
-        private_key = ssl_privkey_to_sexp(priv_key);
-        gnutls_x509_privkey_deinit(priv_key);
-        if (!private_key) {
-            report_failure("Can't extract private key parameters for %s",
-                    uats->keyfile);
-            break;
+    if ((gint)strlen(uats->password) == 0) {
+        priv_key = ssl_load_key(fp);
+    } else {
+        char *err = NULL;
+        priv_key = ssl_load_pkcs12(fp, uats->password, &err);
+        if (err) {
+            report_failure("%s\n", err);
+            g_free(err);
         }
+    }
+    fclose(fp);
 
-        service = (SslService *)g_malloc(sizeof(SslService) + addr_len);
-        service->addr.type = addr_type[at];
-        service->addr.len = addr_len;
-        service->addr.data = ((guchar*)service) + sizeof(SslService);
-        memcpy((void*)service->addr.data, addr_data, addr_len);
-
-        if(strcmp(uats->port,"start_tls")==0) {
-            service->port = 0;
-        } else {
-            service->port = atoi(uats->port);
-        }
+    if (!priv_key) {
+        report_failure("Can't load private key from %s\n", uats->keyfile);
+        return;
+    }
 
-        /*
-         * This gets called outside any dissection scope, so we have to
-         * use a NULL scope and free it ourselves.
-         */
-        address_string = address_to_str(NULL, &service->addr);
-        ssl_debug_printf("ssl_init %s addr '%s' (%s) port '%d' filename '%s' password(only for p12 file) '%s'\n",
-            (addr_type[at] == AT_IPv4) ? "IPv4" : "IPv6", uats->ipaddr, address_string,
-            service->port, uats->keyfile, uats->password);
-        wmem_free(NULL, address_string);
+    key_id = (guchar *) g_malloc0(key_id_len);
+    ret = gnutls_x509_privkey_get_key_id(priv_key, 0, key_id, &key_id_len);
+    if (ret < 0) {
+        report_failure("Can't calculate public key ID for %s: %s",
+                uats->keyfile, gnutls_strerror(ret));
+        goto end;
+    }
+    ssl_print_data("KeyID", key_id, key_id_len);
 
-        ssl_debug_printf("ssl_init private key file %s successfully loaded.\n", uats->keyfile);
+    private_key = ssl_privkey_to_sexp(priv_key);
+    if (!private_key) {
+        report_failure("Can't extract private key parameters for %s", uats->keyfile);
+        goto end;
+    }
 
-        g_hash_table_replace(key_hash, service, private_key);
+    g_hash_table_replace(key_hash, key_id, private_key);
+    key_id = NULL; /* used in key_hash, do not free. */
+    ssl_debug_printf("ssl_init private key file %s successfully loaded.\n", uats->keyfile);
 
-        ssl_association_add(associations, handle, service->port, uats->protocol, tcp, TRUE);
+    {
+        /* Port to subprotocol mapping */
+        int port = atoi(uats->port); /* Also maps "start_tls" -> 0 (wildcard) */
+        ssl_debug_printf("ssl_init port '%d' filename '%s' password(only for p12 file) '%s'\n",
+            port, uats->keyfile, uats->password);
+        ssl_association_add(associations, handle, port, uats->protocol, tcp, TRUE);
     }
 
-    fclose(fp);
+end:
+    gnutls_x509_privkey_deinit(priv_key);
+    g_free(key_id);
 }
 #else
 void
@@ -5657,7 +5562,8 @@ ssl_dissect_hnd_new_ses_ticket(ssl_common_dissect_t *hf, tvbuff_t *tvb,
 void
 ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
                      guint32 offset, packet_info *pinfo,
-                     const SslSession *session, gint is_from_server)
+                     const SslSession *session, SslDecryptSession *ssl _U_,
+                     GHashTable *key_hash _U_, gint is_from_server)
 {
     /* opaque ASN.1Cert<1..2^24-1>;
      *
@@ -5676,9 +5582,9 @@ ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
      */
     enum { CERT_X509, CERT_RPK } cert_type;
     asn1_ctx_t  asn1_ctx;
-
-    if (!tree)
-        return;
+#if defined(HAVE_LIBGNUTLS) && defined(HAVE_LIBGCRYPT)
+    gnutls_datum_t subjectPublicKeyInfo = { NULL, 0 };
+#endif
 
     asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
 
@@ -5689,6 +5595,12 @@ ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
         cert_type = CERT_X509;
     }
 
+#if defined(HAVE_LIBGNUTLS) && defined(HAVE_LIBGCRYPT)
+    /* Ask the pkcs1 dissector to return the public key details */
+    if (ssl)
+        asn1_ctx.private_data = &subjectPublicKeyInfo;
+#endif
+
     switch (cert_type) {
     case CERT_RPK:
         {
@@ -5734,6 +5646,10 @@ ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
                     offset += 3;
 
                     dissect_x509af_Certificate(FALSE, tvb, offset, &asn1_ctx, subtree, hf->hf.hs_certificate);
+#if defined(HAVE_LIBGNUTLS) && defined(HAVE_LIBGCRYPT)
+                    /* Only attempt to get the RSA modulus for the first cert. */
+                    asn1_ctx.private_data = NULL;
+#endif
 
                     offset += cert_length;
                 }
@@ -5741,6 +5657,11 @@ ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
             break;
         }
     }
+
+#if defined(HAVE_LIBGNUTLS) && defined(HAVE_LIBGCRYPT)
+    if (ssl)
+        ssl_find_private_key_by_pubkey(ssl, key_hash, &subjectPublicKeyInfo);
+#endif
 }
 
 void
diff --git a/epan/dissectors/packet-ssl-utils.h b/epan/dissectors/packet-ssl-utils.h
index 08b979f017..c09a39d4fc 100644
--- a/epan/dissectors/packet-ssl-utils.h
+++ b/epan/dissectors/packet-ssl-utils.h
@@ -418,11 +418,6 @@ typedef struct _SslAssociation {
     gboolean from_key_list;
 } SslAssociation;
 
-typedef struct _SslService {
-    address addr;
-    guint port;
-} SslService;
-
 /* User Access Table */
 typedef struct _ssldecrypt_assoc_t {
     char* ipaddr;
@@ -495,10 +490,6 @@ ssl_data_set(StringInfo* buf, const guchar* src, guint len);
 extern gint
 ssl_cipher_setiv(SSL_CIPHER_CTX *cipher, guchar* iv, gint iv_len);
 
-/* Find private key in associations */
-extern void
-ssl_find_private_key(SslDecryptSession *ssl_session, GHashTable *key_hash, GTree* associations, packet_info *pinfo);
-
 /** Search for the specified cipher suite id
  @param num the id of the cipher suite to be searched
  @param cs pointer to the cipher suite struct to be filled
@@ -545,7 +536,7 @@ ssl_equal (gconstpointer v, gconstpointer v2);
 extern guint
 ssl_hash  (gconstpointer v);
 
-extern gint
+extern gboolean
 ssl_private_key_equal (gconstpointer v, gconstpointer v2);
 
 extern guint
@@ -798,7 +789,8 @@ ssl_dissect_hnd_new_ses_ticket(ssl_common_dissect_t *hf, tvbuff_t *tvb,
 extern void
 ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
                      guint32 offset, packet_info *pinfo,
-                     const SslSession *session, gint is_from_server);
+                     const SslSession *session, SslDecryptSession *ssl,
+                     GHashTable *key_hash, gint is_from_server);
 
 extern void
 ssl_dissect_hnd_cert_req(ssl_common_dissect_t *hf, tvbuff_t *tvb,
diff --git a/epan/dissectors/packet-ssl.c b/epan/dissectors/packet-ssl.c
index 447a871c65..d5be9518ee 100644
--- a/epan/dissectors/packet-ssl.c
+++ b/epan/dissectors/packet-ssl.c
@@ -2012,10 +2012,8 @@ dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo,
 
             case SSL_HND_CLIENT_HELLO:
                 if (ssl) {
-                    /* ClientHello is first packet so set direction and try to
-                     * find a private key matching the server port */
+                    /* ClientHello is first packet so set direction */
                     ssl_set_server(session, &pinfo->dst, pinfo->ptype, pinfo->destport);
-                    ssl_find_private_key(ssl, ssl_key_hash, ssl_associations, pinfo);
                 }
                 ssl_dissect_hnd_cli_hello(&dissect_ssl3_hf, tvb, pinfo,
                                           ssl_hand_tree, offset, length, session, ssl,
@@ -2040,7 +2038,8 @@ dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo,
                 break;
 
             case SSL_HND_CERTIFICATE:
-                ssl_dissect_hnd_cert(&dissect_ssl3_hf, tvb, ssl_hand_tree, offset, pinfo, session, is_from_server);
+                ssl_dissect_hnd_cert(&dissect_ssl3_hf, tvb, ssl_hand_tree,
+                        offset, pinfo, session, ssl, ssl_key_hash, is_from_server);
                 break;
 
             case SSL_HND_SERVER_KEY_EXCHG:
@@ -2634,7 +2633,6 @@ dissect_ssl2_hnd_client_hello(tvbuff_t *tvb, packet_info *pinfo,
 
     if (ssl) {
       ssl_set_server(&ssl->session, &pinfo->dst, pinfo->ptype, pinfo->destport);
-      ssl_find_private_key(ssl, ssl_key_hash, ssl_associations, pinfo);
     }
 
     if (ssl)
diff --git a/epan/dissectors/packet-x509af.c b/epan/dissectors/packet-x509af.c
index 3e261ae79e..a5e686ca82 100644
--- a/epan/dissectors/packet-x509af.c
+++ b/epan/dissectors/packet-x509af.c
@@ -41,6 +41,9 @@
 #include "packet-x509if.h"
 #include "packet-x509sat.h"
 #include "packet-ldap.h"
+#if defined(HAVE_LIBGNUTLS)
+#include <gnutls/gnutls.h>
+#endif
 
 #define PNAME  "X.509 Authentication Framework"
 #define PSNAME "X509AF"
@@ -132,7 +135,7 @@ static int hf_x509af_q = -1;                      /* INTEGER */
 static int hf_x509af_g = -1;                      /* INTEGER */
 
 /*--- End of included file: packet-x509af-hf.c ---*/
-#line 49 "../../asn1/x509af/packet-x509af-template.c"
+#line 52 "../../asn1/x509af/packet-x509af-template.c"
 
 /* Initialize the subtree pointers */
 static gint ett_pkix_crl = -1;
@@ -173,8 +176,10 @@ static gint ett_x509af_SET_OF_AttributeType = -1;
 static gint ett_x509af_DSS_Params = -1;
 
 /*--- End of included file: packet-x509af-ett.c ---*/
-#line 53 "../../asn1/x509af/packet-x509af-template.c"
+#line 56 "../../asn1/x509af/packet-x509af-template.c"
 static const char *algorithm_id;
+static void
+x509af_export_publickey(tvbuff_t *tvb, asn1_ctx_t *actx, int offset, int len);
 
 /*--- Included file: packet-x509af-fn.c ---*/
 #line 1 "../../asn1/x509af/packet-x509af-fn.c"
@@ -323,7 +328,7 @@ static const ber_choice_t SubjectName_choice[] = {
 
 static int
 dissect_x509af_SubjectName(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 109 "../../asn1/x509af/x509af.cnf"
+#line 115 "../../asn1/x509af/x509af.cnf"
 
   const char* str;
     offset = dissect_ber_choice(actx, tree, tvb, offset,
@@ -359,9 +364,15 @@ static const ber_sequence_t SubjectPublicKeyInfo_sequence[] = {
 
 int
 dissect_x509af_SubjectPublicKeyInfo(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
+#line 85 "../../asn1/x509af/x509af.cnf"
+  int orig_offset = offset;
+
   offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                    SubjectPublicKeyInfo_sequence, hf_index, ett_x509af_SubjectPublicKeyInfo);
 
+#line 87 "../../asn1/x509af/x509af.cnf"
+  x509af_export_publickey(tvb, actx, orig_offset, offset - orig_offset);
+
   return offset;
 }
 
@@ -369,7 +380,7 @@ dissect_x509af_SubjectPublicKeyInfo(gboolean implicit_tag _U_, tvbuff_t *tvb _U_
 
 static int
 dissect_x509af_T_extnId(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 88 "../../asn1/x509af/x509af.cnf"
+#line 94 "../../asn1/x509af/x509af.cnf"
   const char *name;
 
     offset = dissect_ber_object_identifier_str(implicit_tag, actx, tree, tvb, offset, hf_x509af_extension_id, &actx->external.direct_reference);
@@ -399,7 +410,7 @@ dissect_x509af_BOOLEAN(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset
 
 static int
 dissect_x509af_T_extnValue(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 99 "../../asn1/x509af/x509af.cnf"
+#line 105 "../../asn1/x509af/x509af.cnf"
   gint8 ber_class;
   gboolean pc, ind;
   gint32 tag;
@@ -896,7 +907,23 @@ static int dissect_DSS_Params_PDU(tvbuff_t *tvb _U_, packet_info *pinfo _U_, pro
 
 
 /*--- End of included file: packet-x509af-fn.c ---*/
-#line 55 "../../asn1/x509af/packet-x509af-template.c"
+#line 60 "../../asn1/x509af/packet-x509af-template.c"
+
+/* Exports the SubjectPublicKeyInfo structure as gnutls_datum_t.
+ * actx->private_data is assumed to be a gnutls_datum_t pointer which will be
+ * filled in if non-NULL. */
+static void
+x509af_export_publickey(tvbuff_t *tvb _U_, asn1_ctx_t *actx _U_, int offset _U_, int len _U_)
+{
+#if defined(HAVE_LIBGNUTLS)
+  gnutls_datum_t *subjectPublicKeyInfo = (gnutls_datum_t *)actx->private_data;
+  if (subjectPublicKeyInfo) {
+    subjectPublicKeyInfo->data = (guchar *) tvb_get_ptr(tvb, offset, len);
+    subjectPublicKeyInfo->size = len;
+    actx->private_data = NULL;
+  }
+#endif
+}
 
 const char *x509af_get_last_algorithm_id(void) {
   return algorithm_id;
@@ -1234,7 +1261,7 @@ void proto_register_x509af(void) {
         "INTEGER", HFILL }},
 
 /*--- End of included file: packet-x509af-hfarr.c ---*/
-#line 92 "../../asn1/x509af/packet-x509af-template.c"
+#line 113 "../../asn1/x509af/packet-x509af-template.c"
   };
 
   /* List of subtrees */
@@ -1277,7 +1304,7 @@ void proto_register_x509af(void) {
     &ett_x509af_DSS_Params,
 
 /*--- End of included file: packet-x509af-ettarr.c ---*/
-#line 98 "../../asn1/x509af/packet-x509af-template.c"
+#line 119 "../../asn1/x509af/packet-x509af-template.c"
   };
 
   /* Register protocol */
@@ -1320,7 +1347,7 @@ void proto_reg_handoff_x509af(void) {
 
 
 /*--- End of included file: packet-x509af-dis-tab.c ---*/
-#line 126 "../../asn1/x509af/packet-x509af-template.c"
+#line 147 "../../asn1/x509af/packet-x509af-template.c"
 
 	/*XXX these should really go to a better place but since
 	  I have not that ITU standard, I'll put it here for the time