Merge branch 'feature/genstore' into develop

AUTHORS.md

@@ -9,6 +9,7 @@ patches or pull requests, in chronological order of their first contribution:
 -   Steve Wills   ([swills](https://github.com/swills))
 -   Landon Fuller ([landonf](https://github.com/landonf))
 -   Wayne Jensen  ([wjjensen](https://github.com/wjjensen))
+-   Rory McNamara ([psychomario](https://github.com/psychomario))
 
 Many more individuals have contributed by reporting bugs or feature requests.
 See [issue tracker on Github][1], `NEWS.md` and `git log` for details.

NEWS.md

@@ -1,4 +1,9 @@
 
+### SSLsplit feature/genstore
+
+-   Add options -w and -W to write generated leaf key, original and forged
+    certificates to disk (issue #67 by @psychomario).
+
 ### SSLsplit develop
 
 -   Add signal SIGUSR1 to re-open long-living -l/-L log files (issue #52).

main.c

@@ -117,6 +117,8 @@ main_usage(void)
 "  -K pemfile  use key from pemfile for leaf certs (default: generate)\n"
 "  -t certdir  use cert+chain+key PEM files from certdir to target all sites\n"
 "              matching the common names (non-matching: generate if CA)\n"
+"  -w gendir   write leaf key and only generated certificates to gendir\n"
+"  -W gendir   write leaf key and all certificates to gendir\n"
 "  -O          deny all OCSP requests on all proxyspecs\n"
 "  -P          passthrough SSL connections if they cannot be split because of\n"
 "              client cert auth or no matching cert and no CA (default: drop)\n"
@@ -274,7 +276,7 @@ main(int argc, char *argv[])
 	}
 
 	while ((ch = getopt(argc, argv, OPT_g OPT_G OPT_Z OPT_i "k:c:C:K:t:"
-	                    "OPs:r:R:e:Eu:m:j:p:l:L:S:F:dDVh")) != -1) {
+	                    "OPs:r:R:e:Eu:m:j:p:l:L:S:F:dDVhW:w:")) != -1) {
 		switch (ch) {
 			case 'c':
 				if (opts->cacrt)
@@ -615,6 +617,22 @@ main(int argc, char *argv[])
 				free(lhs);
 				free(rhs);
 				break;
+			case 'W':
+				opts->certgen_writeall = 1;
+				if (opts->certgendir)
+					free(opts->certgendir);
+				opts->certgendir = strdup(optarg);
+				if (!opts->certgendir)
+					oom_die(argv0);
+				break;
+			case 'w':
+				opts->certgen_writeall = 0;
+				if (opts->certgendir)
+					free(opts->certgendir);
+				opts->certgendir = strdup(optarg);
+				if (!opts->certgendir)
+					oom_die(argv0);
+				break;
 			}
 #ifdef HAVE_LOCAL_PROCINFO
 			case 'i':
@@ -747,6 +765,40 @@ main(int argc, char *argv[])
 		}
 	}
 
+	if (opts->certgendir) {
+		char *keyid, *keyfn;
+		int prv;
+		FILE *keyf;
+
+		keyid = ssl_key_identifier(opts->key, 0);
+		if (!keyid) {
+			fprintf(stderr, "%s: error generating key id\n", argv0);
+			exit(EXIT_FAILURE);
+		}
+
+		prv = asprintf(&keyfn, "%s/%s.key", opts->certgendir, keyid);
+		if (prv == -1) {
+			fprintf(stderr, "%s: %s (%i)\n", argv0,
+			                strerror(errno), errno);
+			exit(EXIT_FAILURE);
+		}
+
+		if (!(keyf = fopen(keyfn, "w"))) {
+			fprintf(stderr, "%s: Failed to open '%s' for writing: "
+			                "%s (%i)\n", argv0, keyfn,
+			                strerror(errno), errno);
+			exit(EXIT_FAILURE);
+		}
+		if (!PEM_write_PrivateKey(keyf, opts->key, NULL, 0, 0,
+		                                           NULL, NULL)) {
+			fprintf(stderr, "%s: Failed to write key to '%s': "
+			                "%s (%i)\n", argv0, keyfn,
+			                strerror(errno), errno);
+			exit(EXIT_FAILURE);
+		}
+		fclose(keyf);
+	}
+
 	/* usage checks after defaults */
 	if (opts->dropgroup && !opts->dropuser) {
 		fprintf(stderr, "%s: -m depends on -u.\n", argv0);

opts.c

@@ -105,6 +105,9 @@ opts_free(opts_t *opts)
 	if (opts->contentlog) {
 		free(opts->contentlog);
 	}
+	if (opts->certgendir) {
+		free(opts->certgendir);
+	}
 	if (opts->contentlog_basedir) {
 		free(opts->contentlog_basedir);
 	}

opts.h

@@ -80,7 +80,9 @@ typedef struct opts {
 #ifdef HAVE_LOCAL_PROCINFO
 	unsigned int lprocinfo : 1;
 #endif /* HAVE_LOCAL_PROCINFO */
+	unsigned int certgen_writeall: 1;
 	char *ciphers;
+	char *certgendir;
 	char *tgcrtdir;
 	char *dropuser;
 	char *dropgroup;

pxyconn.c

@@ -40,6 +40,7 @@
 #include "attrib.h"
 #include "proc.h"
 
+#include <sys/stat.h>
 #include <netinet/in.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -120,6 +121,7 @@ typedef struct pxy_conn_ctx {
 
 	/* status flags */
 	unsigned int immutable_cert : 1;  /* 1 if the cert cannot be changed */
+	unsigned int generated_cert : 1;     /* 1 if we generated a new cert */
 	unsigned int connected : 1;       /* 0 until both ends are connected */
 	unsigned int seen_req_header : 1; /* 0 until request header complete */
 	unsigned int seen_resp_header : 1;  /* 0 until response hdr complete */
@@ -147,8 +149,10 @@ typedef struct pxy_conn_ctx {
 	char *http_status_text;
 	char *http_content_length;
 
-	/* log strings from SSL context */
+	/* log strings related to SSL */
 	char *ssl_names;
+	char *origcrtfpr;
+	char *usedcrtfpr;
 
 #ifdef HAVE_LOCAL_PROCINFO
 	/* local process information */
@@ -209,9 +213,7 @@ pxy_conn_ctx_new(proxyspec_t *spec, opts_t *opts,
 	return ctx;
 }
 
-static void
-pxy_conn_ctx_free(pxy_conn_ctx_t *ctx) NONNULL(1);
-static void
+static void NONNULL(1)
 pxy_conn_ctx_free(pxy_conn_ctx_t *ctx)
 {
 #ifdef DEBUG_PROXY
@@ -251,6 +253,12 @@ pxy_conn_ctx_free(pxy_conn_ctx_t *ctx)
 	if (ctx->ssl_names) {
 		free(ctx->ssl_names);
 	}
+	if (ctx->origcrtfpr) {
+		free(ctx->origcrtfpr);
+	}
+	if (ctx->usedcrtfpr) {
+		free(ctx->usedcrtfpr);
+	}
 #ifdef HAVE_LOCAL_PROCINFO
 	if (ctx->lproc.exec_path) {
 		free(ctx->lproc.exec_path);
@@ -312,17 +320,11 @@ pxy_debug_crt(X509 *crt)
 		free(names);
 	}
 
-	unsigned char fpr[SSL_X509_FPRSZ];
-	if (ssl_x509_fingerprint_sha1(crt, fpr) == -1) {
+	char *fpr;
+	if (!(fpr = ssl_x509_fingerprint(crt, 1))) {
 		log_err_printf("Warning: Error generating X509 fingerprint\n");
 	} else {
-		log_dbg_printf("Fingerprint: "     "%02x:%02x:%02x:%02x:"
-		               "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:"
-		               "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
-		               fpr[0],  fpr[1],  fpr[2],  fpr[3],  fpr[4],
-		               fpr[5],  fpr[6],  fpr[7],  fpr[8],  fpr[9],
-		               fpr[10], fpr[11], fpr[12], fpr[13], fpr[14],
-		               fpr[15], fpr[16], fpr[17], fpr[18], fpr[19]);
+		log_dbg_printf("Fingerprint: %s\n", fpr);
 	}
 
 #ifdef DEBUG_CERTIFICATE
@@ -373,7 +375,8 @@ pxy_log_connect_nonhttp(pxy_conn_ctx_t *ctx)
 	} else {
 		rv = asprintf(&msg, "ssl %s %s "
 		              "sni:%s names:%s "
-		              "sproto:%s:%s dproto:%s:%s"
+		              "sproto:%s:%s dproto:%s:%s "
+		              "origcrt:%s usedcrt:%s"
 #ifdef HAVE_LOCAL_PROCINFO
 		              " %s"
 #endif /* HAVE_LOCAL_PROCINFO */
@@ -385,11 +388,13 @@ pxy_log_connect_nonhttp(pxy_conn_ctx_t *ctx)
 		              SSL_get_version(ctx->src.ssl),
 		              SSL_get_cipher(ctx->src.ssl),
 		              SSL_get_version(ctx->dst.ssl),
-		              SSL_get_cipher(ctx->dst.ssl)
+		              SSL_get_cipher(ctx->dst.ssl),
+		              STRORDASH(ctx->origcrtfpr),
+		              STRORDASH(ctx->usedcrtfpr)
 #ifdef HAVE_LOCAL_PROCINFO
 		              , lpi
 #endif /* HAVE_LOCAL_PROCINFO */
-		             );
+		              );
 	}
 	if ((rv < 0) || !msg) {
 		ctx->enomem = 1;
@@ -466,7 +471,8 @@ pxy_log_connect_http(pxy_conn_ctx_t *ctx)
 	} else {
 		rv = asprintf(&msg, "https %s %s %s %s %s %s %s "
 		              "sni:%s names:%s "
-		              "sproto:%s:%s dproto:%s:%s"
+		              "sproto:%s:%s dproto:%s:%s "
+		              "origcrt:%s usedcrt:%s"
 #ifdef HAVE_LOCAL_PROCINFO
 		              " %s"
 #endif /* HAVE_LOCAL_PROCINFO */
@@ -484,6 +490,8 @@ pxy_log_connect_http(pxy_conn_ctx_t *ctx)
 		              SSL_get_cipher(ctx->src.ssl),
 		              SSL_get_version(ctx->dst.ssl),
 		              SSL_get_cipher(ctx->dst.ssl),
+		              STRORDASH(ctx->origcrtfpr),
+		              STRORDASH(ctx->usedcrtfpr),
 #ifdef HAVE_LOCAL_PROCINFO
 		              lpi,
 #endif /* HAVE_LOCAL_PROCINFO */
@@ -724,6 +732,66 @@ pxy_srcsslctx_create(pxy_conn_ctx_t *ctx, X509 *crt, STACK_OF(X509) *chain,
 	return sslctx;
 }
 
+static int
+pxy_srccert_write_to_gendir(pxy_conn_ctx_t *ctx, X509 *crt, int is_orig)
+{
+	char *fn;
+	int rv;
+	struct stat sb;
+	FILE *f;
+
+	if (!ctx->origcrtfpr)
+		return -1;
+	if (is_orig) {
+		rv = asprintf(&fn, "%s/%s.crt", ctx->opts->certgendir,
+		              ctx->origcrtfpr);
+	} else {
+		if (!ctx->usedcrtfpr)
+			return -1;
+		rv = asprintf(&fn, "%s/%s-%s.crt", ctx->opts->certgendir,
+		              ctx->origcrtfpr, ctx->usedcrtfpr);
+	}
+	if (rv == -1) {
+		ctx->enomem = 1;
+		return -1;
+	}
+	if (stat(fn, &sb) == 0) {
+		free(fn);
+		return 0;
+	}
+	if (!(f = fopen(fn, "w"))) {
+		log_err_printf("Failed to open '%s' for writing: %s (%i)\n",
+		               fn, strerror(errno), errno);
+		free(fn);
+		return -1;
+	}
+	if (!PEM_write_X509(f, crt)) {
+		log_err_printf("Failed to write certificate to '%s'\n", fn);
+		fclose(f);
+		free(fn);
+		return -1;
+	}
+	fclose(f);
+	free(fn);
+	return 0;
+}
+
+static void
+pxy_srccert_write(pxy_conn_ctx_t *ctx)
+{
+	if (ctx->opts->certgen_writeall || ctx->generated_cert) {
+		if (pxy_srccert_write_to_gendir(ctx,
+		                SSL_get_certificate(ctx->src.ssl), 0) == -1) {
+			log_err_printf("Failed to write used certificate\n");
+		}
+	}
+	if (ctx->opts->certgen_writeall) {
+		if (pxy_srccert_write_to_gendir(ctx, ctx->origcrt, 1) == -1) {
+			log_err_printf("Failed to write orig certificate\n");
+		}
+	}
+}
+
 static cert_t *
 pxy_srccert_create(pxy_conn_ctx_t *ctx)
 {
@@ -796,6 +864,19 @@ pxy_srccert_create(pxy_conn_ctx_t *ctx)
 		}
 		cert_set_key(cert, ctx->opts->key);
 		cert_set_chain(cert, ctx->opts->chain);
+		ctx->generated_cert = 1;
+	}
+
+	if ((WANT_CONNECT_LOG(ctx) || ctx->opts->certgendir) && ctx->origcrt) {
+		ctx->origcrtfpr = ssl_x509_fingerprint(ctx->origcrt, 0);
+		if (!ctx->origcrtfpr)
+			ctx->enomem = 1;
+	}
+	if ((WANT_CONNECT_LOG(ctx) || ctx->opts->certgen_writeall) &&
+	    cert && cert->crt) {
+		ctx->usedcrtfpr = ssl_x509_fingerprint(cert->crt, 0);
+		if (!ctx->usedcrtfpr)
+			ctx->enomem = 1;
 	}
 
 	return cert;
@@ -919,6 +1000,7 @@ pxy_ossl_servername_cb(SSL *ssl, UNUSED int *al, void *arg)
 			return SSL_TLSEXT_ERR_NOACK;
 		}
 		cachemgr_fkcrt_set(ctx->origcrt, newcrt);
+		ctx->generated_cert = 1;
 		if (OPTS_DEBUG(ctx->opts)) {
 			log_dbg_printf("===> Updated forged server "
 			               "certificate:\n");
@@ -933,6 +1015,16 @@ pxy_ossl_servername_cb(SSL *ssl, UNUSED int *al, void *arg)
 				ctx->enomem = 1;
 			}
 		}
+		if (WANT_CONNECT_LOG(ctx) || ctx->opts->certgendir) {
+			if (ctx->usedcrtfpr) {
+				free(ctx->usedcrtfpr);
+			}
+			ctx->usedcrtfpr = ssl_x509_fingerprint(newcrt, 0);
+			if (!ctx->usedcrtfpr) {
+				ctx->enomem = 1;
+			}
+		}
+
 		newsslctx = pxy_srcsslctx_create(ctx, newcrt, ctx->opts->chain,
 		                                 ctx->opts->key);
 		if (!newsslctx) {
@@ -1760,6 +1852,12 @@ connected:
 			pxy_log_connect_nonhttp(ctx);
 		}
 
+		/* write SSL certificates to gendir */
+		if (this->ssl && (bev == ctx->src.bev) &&
+		    ctx->opts->certgendir) {
+			pxy_srccert_write(ctx);
+		}
+
 		if (OPTS_DEBUG(ctx->opts)) {
 			if (this->ssl) {
 				/* for SSL, we get two connect events */

ssl.c

@@ -421,6 +421,30 @@ ssl_fini(void)
 	CRYPTO_cleanup_all_ex_data();
 }
 
+/*
+ * Format SHA1 hash into newly allocated string, with or without colons.
+ */
+char *
+ssl_sha1_to_str(unsigned char *sha1, int colons)
+{
+	char *str;
+	int rv;
+
+	rv = asprintf(&str, colons ?
+	              "%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X"
+	              "%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X" :
+	              "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X"
+	              "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
+	              sha1[ 0], sha1[ 1], sha1[ 2], sha1[ 3],
+	              sha1[ 4], sha1[ 5], sha1[ 6], sha1[ 7],
+	              sha1[ 8], sha1[ 9], sha1[10], sha1[11],
+	              sha1[12], sha1[13], sha1[14], sha1[15],
+	              sha1[16], sha1[17], sha1[18], sha1[19]);
+	if (rv == -1)
+		return NULL;
+	return str;
+}
+
 /*
  * Format SSL state into newly allocated string.
  * Returns pointer to string that must be freed by caller, or NULL on error.
@@ -1082,6 +1106,21 @@ errout:
 	return -1;
 }
 
+/*
+ * Returns the result of ssl_key_identifier_sha1() as hex characters with or
+ * without colons in a newly allocated string.
+ */
+char *
+ssl_key_identifier(EVP_PKEY *key, int colons)
+{
+	unsigned char id[SSL_KEY_IDSZ];
+
+	if (ssl_key_identifier_sha1(key, id) == -1)
+		return NULL;
+
+	return ssl_sha1_to_str(id, colons);
+}
+
 /*
  * Returns the one-line representation of the subject DN in a newly allocated
  * string which must be freed by the caller.
@@ -1131,6 +1170,21 @@ ssl_x509_fingerprint_sha1(X509 *crt, unsigned char *fpr)
 	return X509_digest(crt, EVP_sha1(), fpr, &sz) ? 0 : -1;
 }
 
+/*
+ * Returns the result of ssl_x509_fingerprint_sha1() as hex characters with or
+ * without colons in a newly allocated string.
+ */
+char *
+ssl_x509_fingerprint(X509 *crt, int colons)
+{
+	unsigned char fpr[SSL_X509_FPRSZ];
+
+	if (ssl_x509_fingerprint_sha1(crt, fpr) == -1)
+		return NULL;
+
+	return ssl_sha1_to_str(fpr, colons);
+}
+
 #ifndef OPENSSL_NO_DH
 /*
  * Increment the reference count of DH parameters in a thread-safe

ssl.h

@@ -113,6 +113,8 @@ int ssl_init(void) WUNRES;
 void ssl_reinit(void);
 void ssl_fini(void);
 
+char * ssl_sha1_to_str(unsigned char *, int) NONNULL(1) MALLOC;
+
 char * ssl_ssl_state_to_str(SSL *) NONNULL(1) MALLOC;
 
 #ifndef OPENSSL_NO_DH
@@ -130,6 +132,7 @@ EVP_PKEY * ssl_key_genrsa(const int) MALLOC;
 void ssl_key_refcount_inc(EVP_PKEY *) NONNULL(1);
 #define SSL_KEY_IDSZ 20
 int ssl_key_identifier_sha1(EVP_PKEY *, unsigned char *) NONNULL(1,2);
+char * ssl_key_identifier(EVP_PKEY *, int) NONNULL(1) MALLOC;
 
 #ifndef OPENSSL_NO_TLSEXT
 int ssl_x509_v3ext_add(X509V3_CTX *, X509 *, char *, char *) NONNULL(1,2,3,4);
@@ -143,6 +146,7 @@ char * ssl_x509_subject(X509 *) NONNULL(1) MALLOC;
 char * ssl_x509_subject_cn(X509 *, size_t *) NONNULL(1,2) MALLOC;
 #define SSL_X509_FPRSZ 20
 int ssl_x509_fingerprint_sha1(X509 *, unsigned char *) NONNULL(1,2);
+char * ssl_x509_fingerprint(X509 *, int) NONNULL(1) MALLOC;
 char ** ssl_x509_names(X509 *) NONNULL(1) MALLOC;
 int ssl_x509_names_match(X509 *, const char *) NONNULL(1,2);
 char * ssl_x509_names_to_str(X509 *) NONNULL(1) MALLOC;

sslsplit.1

@@ -30,15 +30,15 @@ sslsplit \-\- transparent and scalable SSL/TLS interception
 .SH SYNOPSIS
 .na
 .B sslsplit
-[\fB-kCKOPZdDgGsrReumjplLSFi\fP] \fB-c\fP \fIpem\fP
+[\fB-kCKwWOPZdDgGsrReumjplLSFi\fP] \fB-c\fP \fIpem\fP
 \fIproxyspecs\fP [...]
 .br
 .B sslsplit
-[\fB-kCKOPZdDgGsrReumjplLSFi\fP] \fB-c\fP \fIpem\fP \fB-t\fP \fIdir\fP
+[\fB-kCKwWOPZdDgGsrReumjplLSFi\fP] \fB-c\fP \fIpem\fP \fB-t\fP \fIdir\fP
 \fIproxyspecs\fP [...]
 .br
 .B sslsplit
-[\fB-OPZdDgGsrReumjplLSFi\fP] \fB-t\fP \fIdir\fP
+[\fB-OPZwWdDgGsrReumjplLSFi\fP] \fB-t\fP \fIdir\fP
 \fIproxyspecs\fP [...]
 .br
 .B sslsplit -E
@@ -291,6 +291,19 @@ Mac OS X.
 .B \-V
 Display version and compiled features information and exit.
 .TP
+.B \-w \fIgendir\fP
+Write generated keys and certificates to individual files in \fIgendir\fP.
+For keys, the key identifier is used as filename, which consists of the SHA-1
+hash of the ASN.1 bit string of the public key, as referenced by the
+subjectKeyIdentifier extension in certificates.
+For certificates, the SHA-1 fingerprints of the original and the used (forged)
+certificate are combined to form the filename.
+Note that only newly generated certificates are written to disk.
+.TP
+.B \-W \fIgendir\fP
+Same as \fB-w\fP, but also write original certificates and certificates not
+newly generated, such as those loaded from \fB-t\fP.
+.TP
 .B \-Z
 Disable SSL/TLS compression on all connections.  This is useful if your
 limiting factor is CPU, not network bandwidth.
@@ -656,7 +669,7 @@ SSLsplit was written by Daniel Roethlisberger <daniel@roe.ch>.
 
 The following individuals have contributed to the codebase, in chronological
 order of their first contribution:
-Steve Wills, Landon Fuller and Wayne Jensen.
+Steve Wills, Landon Fuller, Wayne Jensen and Rory McNamara.
 .SH BUGS
 Use Github for submission of bug reports or patches:
 .LP