]> code.citadel.org Git - citadel.git/blobdiff - citadel/serv_crypto.c
* During SSL initialization, create the "keys" directory if it does not
[citadel.git] / citadel / serv_crypto.c
index b4e25f1a9828b9d6b2bfbd746cfbd7f5a750c194..2b51706c7b094c3cc8749c36bda13dcd8d50a7ea 100644 (file)
 /* $Id$ */
 
+#include <string.h>
 #include <unistd.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include "sysdep.h"
+
 #ifdef HAVE_OPENSSL
 #include <openssl/ssl.h>
 #include <openssl/err.h>
 #include <openssl/rand.h>
 #endif
+
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
+#endif
+
 #ifdef HAVE_PTHREAD_H
 #include <pthread.h>
 #endif
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
 #include <stdio.h>
 #include "server.h"
 #include "serv_crypto.h"
 #include "sysdep_decls.h"
-#include "dynloader.h"
+#include "serv_extensions.h"
 
 
 #ifdef HAVE_OPENSSL
-SSL_CTX *ssl_ctx;                              /* SSL context */
-pthread_mutex_t **SSLCritters;                 /* Things needing locking */
+SSL_CTX *ssl_ctx;              /* SSL context */
+pthread_mutex_t **SSLCritters; /* Things needing locking */
+
+static unsigned long id_callback(void)
+{
+       return (unsigned long) pthread_self();
+}
+
+ /*
+  * Set up the cert things on the server side. We do need both the
+  * private key (in key_file) and the cert (in cert_file).
+  * Both files may be identical.
+  *
+  * This function is taken from OpenSSL apps/s_cb.c
+  */
+
+static int ctdl_install_certificate(SSL_CTX * ctx,
+                         const char *cert_file, const char *key_file)
+{
+       if (cert_file != NULL) {
+               if (SSL_CTX_use_certificate_file(ctx, cert_file,
+                                                SSL_FILETYPE_PEM) <= 0) {
+                       lprintf(3, "unable to get certificate from '%s'",
+                               cert_file);
+                       return (0);
+               }
+               if (key_file == NULL)
+                       key_file = cert_file;
+               if (SSL_CTX_use_PrivateKey_file(ctx, key_file,
+                                               SSL_FILETYPE_PEM) <= 0) {
+                       lprintf(3, "unable to get private key from '%s'",
+                               key_file);
+                       return (0);
+               }
+               /* Now we know that a key and cert have been set against
+                * the SSL context */
+               if (!SSL_CTX_check_private_key(ctx)) {
+                       lprintf(3,
+                               "Private key does not match the certificate public key");
+                       return (0);
+               }
+       }
+       return (1);
+}
 
 
 void init_ssl(void)
 {
        SSL_METHOD *ssl_method;
        DH *dh;
-       
+       RSA *rsa=NULL;
+       FILE *fp;
+
+       if (!access("/var/run/egd-pool", F_OK))
+               RAND_egd("/var/run/egd-pool");
+
        if (!RAND_status()) {
-               lprintf(2, "PRNG not adequately seeded, won't do SSL/TLS\n");
+               lprintf(2,
+                       "PRNG not adequately seeded, won't do SSL/TLS\n");
                return;
        }
-       SSLCritters = mallok(CRYPTO_num_locks() * sizeof (pthread_mutex_t *));
+       SSLCritters =
+           mallok(CRYPTO_num_locks() * sizeof(pthread_mutex_t *));
        if (!SSLCritters) {
                lprintf(1, "citserver: can't allocate memory!!\n");
                /* Nothing's been initialized, just die */
@@ -40,10 +109,11 @@ void init_ssl(void)
        } else {
                int a;
 
-               for (a=0; a<CRYPTO_num_locks(); a++) {
-                       SSLCritters[a] = mallok(sizeof (pthread_mutex_t));
+               for (a = 0; a < CRYPTO_num_locks(); a++) {
+                       SSLCritters[a] = mallok(sizeof(pthread_mutex_t));
                        if (!SSLCritters[a]) {
-                               lprintf(1, "citserver: can't allocate memory!!\n");
+                               lprintf(1,
+                                       "citserver: can't allocate memory!!\n");
                                /* Nothing's been initialized, just die */
                                exit(1);
                        }
@@ -59,7 +129,7 @@ void init_ssl(void)
        ssl_method = SSLv23_server_method();
        if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
                lprintf(2, "SSL_CTX_new failed: %s\n",
-                               ERR_reason_error_string(ERR_get_error()));
+                       ERR_reason_error_string(ERR_get_error()));
                return;
        }
        if (!(SSL_CTX_set_cipher_list(ssl_ctx, CIT_CIPHERS))) {
@@ -71,31 +141,32 @@ void init_ssl(void)
 #if 0
 #if SSLEAY_VERSION_NUMBER >= 0x00906000L
        SSL_CTX_set_mode(ssl_ctx, SSL_CTX_get_mode(ssl_ctx) |
-                       SSL_MODE_AUTO_RETRY);
+                        SSL_MODE_AUTO_RETRY);
 #endif
 #endif
+
        CRYPTO_set_locking_callback(ssl_lock);
-       CRYPTO_set_id_callback(pthread_self);
+       CRYPTO_set_id_callback(id_callback);
 
        /* Load DH parameters into the context */
        dh = DH_new();
        if (!dh) {
                lprintf(2, "init_ssl() can't allocate a DH object: %s\n",
-                               ERR_reason_error_string(ERR_get_error()));
+                       ERR_reason_error_string(ERR_get_error()));
                SSL_CTX_free(ssl_ctx);
                ssl_ctx = NULL;
                return;
        }
        if (!(BN_hex2bn(&(dh->p), DH_P))) {
                lprintf(2, "init_ssl() can't assign DH_P: %s\n",
-                               ERR_reason_error_string(ERR_get_error()));
+                       ERR_reason_error_string(ERR_get_error()));
                SSL_CTX_free(ssl_ctx);
                ssl_ctx = NULL;
                return;
        }
        if (!(BN_hex2bn(&(dh->g), DH_G))) {
                lprintf(2, "init_ssl() can't assign DH_G: %s\n",
-                               ERR_reason_error_string(ERR_get_error()));
+                       ERR_reason_error_string(ERR_get_error()));
                SSL_CTX_free(ssl_ctx);
                ssl_ctx = NULL;
                return;
@@ -104,11 +175,62 @@ void init_ssl(void)
        SSL_CTX_set_tmp_dh(ssl_ctx, dh);
        DH_free(dh);
 
+       /* Get our certificates in order.
+        * First, create the key/cert directory if it's not there already...
+        */
+       mkdir(CTDL_CRYPTO_DIR, 0700);
+
+       /*
+        * Generate a key pair if we don't have one.
+        */
+       if (access(CTDL_KEY_PATH, R_OK) != 0) {
+               lprintf(3, "Generating RSA key pair.\n");
+               rsa = RSA_generate_key(1024,    /* modulus size */
+                                       65537,  /* exponent */
+                                       NULL,   /* no callback */
+                                       NULL);  /* no callback */
+               if (rsa == NULL) {
+                       lprintf(2, "Key generation failed: %s\n",
+                               ERR_reason_error_string(ERR_get_error()));
+               }
+               if (rsa != NULL) {
+                       fp = fopen(CTDL_KEY_PATH, "w");
+                       if (fp != NULL) {
+                               chmod(CTDL_KEY_PATH, 0600);
+                               if (PEM_write_RSAPrivateKey(fp, /* the file */
+                                                       rsa,    /* the key */
+                                                       NULL,   /* no enc */
+                                                       NULL,   /* no passphr */
+                                                       0,      /* no passphr */
+                                                       NULL,   /* no callbk */
+                                                       NULL    /* no callbk */
+                               ) != 1) {
+                                       lprintf(2, "Cannot write key: %s\n",
+                                               ERR_reason_error_string(ERR_get_error()));
+                                       unlink(CTDL_KEY_PATH);
+                               }
+                               fclose(fp);
+                       }
+                       RSA_free(rsa);
+               }
+       }
+
+       /*
+        * Now try to bind to the key and certificate.
+        */
+       if (ctdl_install_certificate(ssl_ctx,
+                       CTDL_CER_PATH,
+                       CTDL_KEY_PATH) != 1)
+       {
+               lprintf(2, "Cannot install certificate: %s\n",
+                               ERR_reason_error_string(ERR_get_error()));
+       }
+
        /* Finally let the server know we're here */
        CtdlRegisterProtoHook(cmd_stls, "STLS", "Start SSL/TLS session");
-       CtdlRegisterProtoHook(cmd_gtls, "GTLS", "Get SSL/TLS session status");
-       CtdlRegisterProtoHook(cmd_etls, "ETLS", "End SSL/TLS session");
-       CtdlRegisterSessionHook(endtls_atlogout, EVT_STOP);
+       CtdlRegisterProtoHook(cmd_gtls, "GTLS",
+                             "Get SSL/TLS session status");
+       CtdlRegisterSessionHook(endtls, EVT_STOP);
 }
 
 
@@ -130,18 +252,21 @@ void client_write_ssl(char *buf, int nbytes)
                                ERR_print_errors_fp(stderr);
                        }
                }
-               retval = SSL_write(CC->ssl, &buf[nbytes - nremain], nremain);
+               retval =
+                   SSL_write(CC->ssl, &buf[nbytes - nremain], nremain);
                if (retval < 1) {
                        long errval;
 
                        errval = SSL_get_error(CC->ssl, retval);
                        if (errval == SSL_ERROR_WANT_READ ||
-                                       errval == SSL_ERROR_WANT_WRITE) {
+                           errval == SSL_ERROR_WANT_WRITE) {
                                sleep(1);
                                continue;
                        }
-                       lprintf(9, "SSL_write got error %ld\n", errval);
-                       endtls(1);
+                       lprintf(9, "SSL_write got error %ld, ret %d\n", errval, retval);
+                       if (retval == -1)
+                               lprintf(9, "errno is %d\n", errno);
+                       endtls();
                        client_write(&buf[nbytes - nremain], nremain);
                        return;
                }
@@ -155,81 +280,91 @@ void client_write_ssl(char *buf, int nbytes)
  */
 int client_read_ssl(char *buf, int bytes, int timeout)
 {
-       int len,rlen;
+#if 0
        fd_set rfds;
        struct timeval tv;
        int retval;
        int s;
+#endif
+       int len, rlen;
        char junk[1];
 
        len = 0;
-       while(len<bytes) {
+       while (len < bytes) {
+#if 0
+               /*
+                * This code is disabled because we don't need it when
+                * using blocking reads (which we are). -IO
+                */
                FD_ZERO(&rfds);
                s = BIO_get_fd(CC->ssl->rbio, NULL);
                FD_SET(s, &rfds);
                tv.tv_sec = timeout;
                tv.tv_usec = 0;
 
-               retval = select(s+1, &rfds, NULL, NULL, &tv);
+               retval = select(s + 1, &rfds, NULL, NULL, &tv);
 
                if (FD_ISSET(s, &rfds) == 0) {
-                       return(0);
+                       return (0);
                }
 
+#endif
                if (SSL_want_read(CC->ssl)) {
                        if ((SSL_write(CC->ssl, junk, 0)) < 1) {
                                lprintf(9, "SSL_write in client_read:\n");
                                ERR_print_errors_fp(stderr);
                        }
                }
-               rlen = SSL_read(CC->ssl, &buf[len], bytes-len);
-               if (rlen<1) {
+               rlen = SSL_read(CC->ssl, &buf[len], bytes - len);
+               if (rlen < 1) {
                        long errval;
 
                        errval = SSL_get_error(CC->ssl, rlen);
                        if (errval == SSL_ERROR_WANT_READ ||
-                                       errval == SSL_ERROR_WANT_WRITE) {
+                           errval == SSL_ERROR_WANT_WRITE) {
                                sleep(1);
                                continue;
                        }
                        lprintf(9, "SSL_read got error %ld\n", errval);
-                       endtls(1);
-                       return (client_read_to(&buf[len], bytes - len, timeout));
+                       endtls();
+                       return (client_read_to
+                               (&buf[len], bytes - len, timeout));
                }
                len += rlen;
        }
-       return(1);
+       return (1);
 }
 
 
 /*
- * cmd_stls() starts SSL/TLS encryption for the current session
+ * CtdlStartTLS() starts SSL/TLS encryption for the current session.  It
+ * must be supplied with pre-generated strings for responses of "ok," "no
+ * support for TLS," and "error" so that we can use this in any protocol.
  */
-void cmd_stls(char *params)
-{
+void CtdlStartTLS(char *ok_response, char *nosup_response,
+                       char *error_response) {
+
        int retval, bits, alg_bits;
 
        if (!ssl_ctx) {
-               cprintf("%d No SSL_CTX available\n", ERROR);
+               cprintf("%s", nosup_response);
                return;
        }
        if (!(CC->ssl = SSL_new(ssl_ctx))) {
                lprintf(2, "SSL_new failed: %s\n",
-                               ERR_reason_error_string(ERR_peek_error()));
-               cprintf("%d SSL_new: %s\n", ERROR,
                                ERR_reason_error_string(ERR_get_error()));
+               cprintf("%s", error_response);
                return;
        }
        if (!(SSL_set_fd(CC->ssl, CC->client_socket))) {
                lprintf(2, "SSL_set_fd failed: %s\n",
-                               ERR_reason_error_string(ERR_peek_error()));
+                       ERR_reason_error_string(ERR_get_error()));
                SSL_free(CC->ssl);
                CC->ssl = NULL;
-               cprintf("%d SSL_set_fd: %s\n", ERROR,
-                               ERR_reason_error_string(ERR_get_error()));
+               cprintf("%s", error_response);
                return;
        }
-       cprintf("%d \n", OK);
+       cprintf("%s", ok_response);
        retval = SSL_accept(CC->ssl);
        if (retval < 1) {
                /*
@@ -241,76 +376,82 @@ void cmd_stls(char *params)
 
                errval = SSL_get_error(CC->ssl, retval);
                lprintf(2, "SSL_accept failed: %s\n",
-                               ERR_reason_error_string(ERR_get_error()));
+                       ERR_reason_error_string(ERR_get_error()));
                SSL_free(CC->ssl);
                CC->ssl = NULL;
                return;
        }
        BIO_set_close(CC->ssl->rbio, BIO_NOCLOSE);
-       bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl), &alg_bits);
-       lprintf(3, "Session %d using %s on %s (%d of %d bits)\n", CC->cs_pid,
-                       SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
-                       SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
-                       bits, alg_bits);
+       bits =
+           SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl),
+                               &alg_bits);
+       lprintf(3, "SSL/TLS using %s on %s (%d of %d bits)\n",
+               SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
+               SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
+               bits, alg_bits);
        CC->redirect_ssl = 1;
 }
 
 
+/*
+ * cmd_stls() starts SSL/TLS encryption for the current session
+ */
+void cmd_stls(char *params)
+{
+       char ok_response[SIZ];
+       char nosup_response[SIZ];
+       char error_response[SIZ];
+
+       sprintf(ok_response,
+               "%d Begin TLS negotiation now\n",
+               CIT_OK);
+       sprintf(nosup_response,
+               "%d TLS not supported here\n",
+               ERROR + CMD_NOT_SUPPORTED);
+       sprintf(error_response,
+               "%d TLS negotiation error\n",
+               ERROR + INTERNAL_ERROR);
+
+       CtdlStartTLS(ok_response, nosup_response, error_response);
+}
+
+
 /*
  * cmd_gtls() returns status info about the TLS connection
  */
 void cmd_gtls(char *params)
 {
        int bits, alg_bits;
-       
+
        if (!CC->ssl || !CC->redirect_ssl) {
                cprintf("%d Session is not encrypted.\n", ERROR);
                return;
        }
-       bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl), &alg_bits);
-       cprintf("%d %s|%s|%d|%d\n", OK,
+       bits =
+           SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl),
+                               &alg_bits);
+       cprintf("%d %s|%s|%d|%d\n", CIT_OK,
                SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
                SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
                alg_bits, bits);
 }
 
 
-/* Logout function hook */
-void endtls_atlogout(void)
-{
-       endtls(1);
-}
-
-
-/* Command function hook */
-void cmd_etls(char *params)
-{
-       endtls(0);
-}
-
-
 /*
  * endtls() shuts down the TLS connection
- * Parameter is NULL for client request, CitContext * for server request
  *
  * WARNING:  This may make your session vulnerable to a known plaintext
  * attack in the current implmentation.
  */
-void endtls(int who)
+void endtls(void)
 {
-       lprintf(7, "Session %d ending SSL/TLS%s\n", CC->cs_pid,
-                       (who) ? "" : " at client request");
+       lprintf(7, "Ending SSL/TLS\n");
 
-       if (!who) {
-               if (!CC->ssl) {
-                       cprintf("%d Connection is not encrypted.\n", ERROR);
-                       return;
-               }
-               cprintf("%d Now stop encryption.\n", OK);
-       } else if (!CC->ssl) {
+       if (!CC->ssl) {
+               CC->redirect_ssl = 0;
                return;
        }
-       
+
        SSL_shutdown(CC->ssl);
        SSL_free(CC->ssl);
        CC->ssl = NULL;
@@ -328,4 +469,4 @@ void ssl_lock(int mode, int n, const char *file, int line)
        else
                pthread_mutex_unlock(SSLCritters[n]);
 }
-#endif /* HAVE_OPENSSL */
+#endif                         /* HAVE_OPENSSL */