X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=webcit%2Fcrypto.c;h=5df3e61a13111d676866ed24b6209d6d7505b839;hb=HEAD;hp=0d0f080b0dfed63f0a17cf48c3ff9a7b1db720a6;hpb=b68b70e7a354aa2b3e550569514d303847e6379f;p=citadel.git

diff --git a/webcit/crypto.c b/webcit/crypto.c
index 0d0f080b0..845113791 100644
--- a/webcit/crypto.c
+++ b/webcit/crypto.c
@@ -1,4 +1,4 @@
-// Copyright (c) 1996-2021 by the citadel.org team
+// Copyright (c) 1996-2022 by the citadel.org team
 //
 // This program is open source software.  You can redistribute it and/or
 // modify it under the terms of the GNU General Public License, version 3.
@@ -12,326 +12,102 @@
 #ifdef HAVE_OPENSSL
 
 #include "webcit.h"
-#include "webserver.h"
 
-/* where to find the keys */
-#define	CTDL_CRYPTO_DIR		ctdl_key_dir
-#define CTDL_KEY_PATH		file_crpt_file_key
-#define CTDL_CSR_PATH		file_crpt_file_csr
-#define CTDL_CER_PATH		file_crpt_file_cer
-#define SIGN_DAYS		3650			// how long our self-signed certificate should live
+
 
 SSL_CTX *ssl_ctx;		// Global SSL context
+char key_file[PATH_MAX] = "";
+char cert_file[PATH_MAX] = "";
 char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
 
 pthread_key_t ThreadSSL;	// Per-thread SSL context
 
-void shutdown_ssl(void) {
-	ERR_free_strings();
-}
-
-
-void generate_key(char *keyfilename) {
-	int ret = 0;
-	RSA *rsa = NULL;
-	BIGNUM *bne = NULL;
-	int bits = 2048;
-	unsigned long e = RSA_F4;
-	FILE *fp;
-
-	if (access(keyfilename, R_OK) == 0) {		// We already have a key -- don't generate a new one.
-		return;
-	}
-
-	syslog(LOG_INFO, "crypto: generating RSA key pair");
- 
-	// generate rsa key
-	bne = BN_new();
-	ret = BN_set_word(bne,e);
-	if (ret != 1) {
-		goto free_all;
-	}
- 
-	rsa = RSA_new();
-	ret = RSA_generate_key_ex(rsa, bits, bne, NULL);
-	if (ret != 1) {
-		goto free_all;
-	}
-
-	// write the key file
-	fp = fopen(keyfilename, "w");
-	if (fp != NULL) {
-		chmod(file_crpt_file_key, 0600);
-		if (PEM_write_RSAPrivateKey(fp,	// the file
-					rsa,	// the key
-					NULL,	// no enc
-					NULL,	// no passphrase
-					0,	// no passphrase
-					NULL,	// no callback
-					NULL	// no callback
-		) != 1) {
-			syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
-			unlink(keyfilename);
-		}
-		fclose(fp);
-	}
 
-	// Free the memory we used
-free_all:
-	RSA_free(rsa);
-	BN_free(bne);
-}
+// Set the private key and certificate chain for the global SSL Context.
+// This is called during initialization, and can be called again later if the certificate changes.
+void bind_to_key_and_certificate(void) {
 
+	SSL_CTX *old_ctx, *new_ctx;
 
-// initialize ssl engine, load certs and initialize openssl internals
-void init_ssl(void) {
-	const SSL_METHOD *ssl_method;
-	RSA *rsa=NULL;
-	X509_REQ *req = NULL;
-	X509 *cer = NULL;
-	EVP_PKEY *pk = NULL;
-	EVP_PKEY *req_pkey = NULL;
-	X509_NAME *name = NULL;
-	FILE *fp;
-	char buf[SIZ];
-	int rv = 0;
-
-#ifndef OPENSSL_NO_EGD
-	if (!access("/var/run/egd-pool", F_OK)) {
-		RAND_egd("/var/run/egd-pool");
+	if (IsEmptyStr(key_file)) {
+		snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir);
 	}
-#endif
-
-	if (!RAND_status()) {
-		syslog(LOG_WARNING, "PRNG not adequately seeded, won't do SSL/TLS");
-		return;
+	if (IsEmptyStr(cert_file)) {
+		snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir);
 	}
 
-	// Initialize SSL transport layer
-	SSL_library_init();
-	SSL_load_error_strings();
-	ssl_method = SSLv23_server_method();
-	if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
+	if (!(new_ctx = SSL_CTX_new(SSLv23_server_method()))) {
 		syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 		return;
 	}
 
 	syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
-	if (!(SSL_CTX_set_cipher_list(ssl_ctx, ssl_cipher_list))) {
+	if (!(SSL_CTX_set_cipher_list(new_ctx, ssl_cipher_list))) {
 		syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
 		return;
 	}
 
-	CRYPTO_set_locking_callback(ssl_lock);
-	CRYPTO_set_id_callback(id_callback);
-
-	// Get our certificates in order.
-	// First, create the key/cert directory if it's not there already...
-	mkdir(CTDL_CRYPTO_DIR, 0700);
-
-	// Before attempting to generate keys/certificates, first try
-	// link to them from the Citadel server if it's on the same host.
-	// We ignore any error return because it either meant that there
-	// was nothing in Citadel to link from (in which case we just
-	// generate new files) or the target files already exist (which
-	// is not fatal either).
-	if (!strcasecmp(ctdlhost, "uds")) {
-		sprintf(buf, "%s/keys/citadel.key", ctdlport);
-		rv = symlink(buf, CTDL_KEY_PATH);
-		if (!rv) {
-			syslog(LOG_DEBUG, "%s", strerror(errno));
-		}
-		sprintf(buf, "%s/keys/citadel.csr", ctdlport);
-		rv = symlink(buf, CTDL_CSR_PATH);
-		if (!rv) {
-			syslog(LOG_DEBUG, "%s", strerror(errno));
-		}
-		sprintf(buf, "%s/keys/citadel.cer", ctdlport);
-		rv = symlink(buf, CTDL_CER_PATH);
-		if (!rv) {
-			syslog(LOG_DEBUG, "%s", strerror(errno));
-		}
-	}
+	syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file);
 
-	// If we still don't have a private key, generate one.
-	generate_key(CTDL_KEY_PATH);
-
-	// If there is no certificate file on disk, we will be generating a self-signed certificate
-	// in the next step.  Therefore, if we have neither a CSR nor a certificate, generate
-	// the CSR in this step so that the next step may commence.
-	if ( (access(CTDL_CER_PATH, R_OK) != 0) && (access(CTDL_CSR_PATH, R_OK) != 0) ) {
-		syslog(LOG_INFO, "Generating a certificate signing request.");
-
-		// Read our key from the file.  No, we don't just keep this
-		// in memory from the above key-generation function, because
-		// there is the possibility that the key was already on disk
-		// and we didn't just generate it now.
-		fp = fopen(CTDL_KEY_PATH, "r");
-		if (fp) {
-			rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
-			fclose(fp);
-		}
+	SSL_CTX_use_certificate_chain_file(new_ctx, cert_file);
+	SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM);
 
-		if (rsa) {
-			// Create a public key from the private key
-			if (pk=EVP_PKEY_new(), pk != NULL) {
-				EVP_PKEY_assign_RSA(pk, rsa);
-				if (req = X509_REQ_new(), req != NULL) {
-					const char *env;
-					// Set the public key
-					X509_REQ_set_pubkey(req, pk);
-					X509_REQ_set_version(req, 0L);
-
-					name = X509_REQ_get_subject_name(req);
-
-					// Tell it who we are
-					env = getenv("O");
-					if (env == NULL) {
-						env = "Organization name";
-					}
-
-					X509_NAME_add_entry_by_txt(
-						name, "O",
-						MBSTRING_ASC, 
-						(unsigned char*)env, 
-						-1, -1, 0
-					);
-
-					env = getenv("OU");
-					if (env == NULL) {
-						env = "Citadel server";
-					}
-
-					X509_NAME_add_entry_by_txt(
-						name, "OU",
-						MBSTRING_ASC, 
-						(unsigned char*)env, 
-						-1, -1, 0
-					);
-
-					env = getenv("CN");
-					if (env == NULL)
-						env = "*";
-
-					X509_NAME_add_entry_by_txt(
-						name, "CN",
-						MBSTRING_ASC, 
-						(unsigned char*)env,
-						-1, -1, 0
-					);
-				
-					X509_REQ_set_subject_name(req, name);
-
-					// Sign the CSR
-					if (!X509_REQ_sign(req, pk, EVP_md5())) {
-						syslog(LOG_WARNING, "X509_REQ_sign(): error");
-					}
-					else {
-						// Write it to disk.
-						fp = fopen(CTDL_CSR_PATH, "w");
-						if (fp != NULL) {
-							chmod(CTDL_CSR_PATH, 0600);
-							PEM_write_X509_REQ(fp, req);
-							fclose(fp);
-						}
-						else {
-							syslog(LOG_WARNING, "Cannot write key: %s", CTDL_CSR_PATH);
-							ShutDownWebcit();
-							exit(0);
-						}
-					}
-
-					X509_REQ_free(req);
-				}
-			}
-			RSA_free(rsa);
-		}
-		else {
-			syslog(LOG_WARNING, "Unable to read private key.");
-		}
+	if ( !SSL_CTX_check_private_key(new_ctx) ) {
+		syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
 	}
 
-	// Generate a self-signed certificate if we don't have one.
-	if (access(CTDL_CER_PATH, R_OK) != 0) {
-		syslog(LOG_INFO, "Generating a self-signed certificate.\n");
+	old_ctx = ssl_ctx;
+	ssl_ctx = new_ctx;
+	sleep(1);
+	SSL_CTX_free(old_ctx);
+}
 
-		// Same deal as before: always read the key from disk because
-		// it may or may not have just been generated.
-		fp = fopen(CTDL_KEY_PATH, "r");
-		if (fp) {
-			rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
-			fclose(fp);
-		}
 
-		// This also holds true for the CSR.
-		req = NULL;
-		cer = NULL;
-		pk = NULL;
-		if (rsa) {
-			if (pk=EVP_PKEY_new(), pk != NULL) {
-				EVP_PKEY_assign_RSA(pk, rsa);
-			}
+// initialize ssl engine, load certs and initialize openssl internals
+void init_ssl(void) {
 
-			fp = fopen(CTDL_CSR_PATH, "r");
-			if (fp) {
-				req = PEM_read_X509_REQ(fp, NULL, NULL, NULL);
-				fclose(fp);
-			}
+	// Initialize the OpenSSL library
+	SSL_load_error_strings();
+	ERR_load_crypto_strings();
+	OpenSSL_add_all_algorithms();
+	SSL_library_init();
 
-			if (req) {
-				if (cer = X509_new(), cer != NULL) {
-
-					ASN1_INTEGER_set(X509_get_serialNumber(cer), 0);
-					X509_set_issuer_name(cer, X509_REQ_get_subject_name(req));
-					X509_set_subject_name(cer, X509_REQ_get_subject_name(req));
-					X509_gmtime_adj(X509_get_notBefore(cer), 0);
-					X509_gmtime_adj(X509_get_notAfter(cer),(long)60*60*24*SIGN_DAYS);
-
-					req_pkey = X509_REQ_get_pubkey(req);
-					X509_set_pubkey(cer, req_pkey);
-					EVP_PKEY_free(req_pkey);
-					
-					// Sign the cert
-					if (!X509_sign(cer, pk, EVP_md5())) {
-						syslog(LOG_WARNING, "X509_sign(): error");
-					}
-					else {
-						// Write it to disk.
-						fp = fopen(CTDL_CER_PATH, "w");
-						if (fp != NULL) {
-							chmod(CTDL_CER_PATH, 0600);
-							PEM_write_X509(fp, cer);
-							fclose(fp);
-						}
-						else {
-							syslog(LOG_WARNING, "Cannot write key: %s", CTDL_CER_PATH);
-							ShutDownWebcit();
-							exit(0);
-						}
-					}
-					X509_free(cer);
-				}
-			}
-			RSA_free(rsa);
-		}
+	// Now try to bind to the key and certificate.
+	bind_to_key_and_certificate();
+}
+
+
+// Check the modification time of the key and certificate -- reload if either one changed
+void update_key_and_cert_if_needed(void) {
+	static time_t previous_mtime = 0;
+	struct stat keystat;
+	struct stat certstat;
+
+	if (stat(key_file, &keystat) != 0) {
+		syslog(LOG_ERR, "%s: %s", key_file, strerror(errno));
+		return;
+	}
+	if (stat(cert_file, &certstat) != 0) {
+		syslog(LOG_ERR, "%s: %s", cert_file, strerror(errno));
+		return;
 	}
 
-	// Now try to bind to the key and certificate.
-	// Note that we use SSL_CTX_use_certificate_chain_file() which allows
-	// the certificate file to contain intermediate certificates.
-	SSL_CTX_use_certificate_chain_file(ssl_ctx, CTDL_CER_PATH);
-	SSL_CTX_use_PrivateKey_file(ssl_ctx, CTDL_KEY_PATH, SSL_FILETYPE_PEM);
-	if ( !SSL_CTX_check_private_key(ssl_ctx) ) {
-		syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
+	if ((keystat.st_mtime + certstat.st_mtime) != previous_mtime) {
+		bind_to_key_and_certificate();
+		previous_mtime = keystat.st_mtime + certstat.st_mtime;
 	}
 }
 
 
 // starts SSL/TLS encryption for the current session.
 int starttls(int sock) {
-	int retval, bits, alg_bits;
 	SSL *newssl;
+	int retval, bits, alg_bits;
 
+	// Check the modification time of the key and certificate -- reload if they changed
+	update_key_and_cert_if_needed();
+	
+	// SSL is a thread-specific thing, I think.
 	pthread_setspecific(ThreadSSL, NULL);
 
 	if (!ssl_ctx) {
@@ -357,34 +133,16 @@ int starttls(int sock) {
 		errval = SSL_get_error(newssl, retval);
 		ssl_error_reason = ERR_reason_error_string(ERR_get_error());
 		if (ssl_error_reason == NULL) {
-			syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
-		}
-		else {
-			syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
-		}
-		sleeeeeeeeeep(1);
-		retval = SSL_accept(newssl);
-	}
-	if (retval < 1) {
-		long errval;
-		const char *ssl_error_reason = NULL;
-
-		errval = SSL_get_error(newssl, retval);
-		ssl_error_reason = ERR_reason_error_string(ERR_get_error());
-		if (ssl_error_reason == NULL) {
-			syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d (%s)", errval, retval, strerror(errval));
+			syslog(LOG_WARNING, "first SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
 		}
 		else {
-			syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
+			syslog(LOG_WARNING, "first SSL_accept failed: %s", ssl_error_reason);
 		}
-		SSL_free(newssl);
-		newssl = NULL;
-		return(4);
 	}
 	else {
 		syslog(LOG_INFO, "SSL_accept success");
 	}
-	/*r = */BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE);
+	BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE);
 	bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(newssl), &alg_bits);
 	syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
 		SSL_CIPHER_get_name(SSL_get_current_cipher(newssl)),
@@ -443,7 +201,7 @@ int client_write_ssl(const StrBuf *Buf) {
 				sleeeeeeeeeep(1);
 				continue;
 			}
-			syslog(LOG_WARNING, "SSL_write got error %ld, ret %d", errval, retval);
+			syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error()));
 			if (retval == -1) {
 				syslog(LOG_WARNING, "errno is %d\n", errno);
 			}
@@ -480,7 +238,7 @@ int client_read_sslbuffer(StrBuf *buf, int timeout) {
 				sleeeeeeeeeep(1);
 				continue;
 			}
-			syslog(LOG_WARNING, "SSL_read got error %ld", errval);
+			syslog(LOG_WARNING, "SSL_read in client_read: %s", ERR_reason_error_string(ERR_get_error()));
 			endtls();
 			return (-1);
 		}