diff options
| -rw-r--r-- | lib/Makefile.inc | 14 | ||||
| -rw-r--r-- | lib/vtls/keylog.c | 156 | ||||
| -rw-r--r-- | lib/vtls/keylog.h | 56 | ||||
| -rw-r--r-- | lib/vtls/openssl.c | 145 |
4 files changed, 246 insertions, 125 deletions
diff --git a/lib/Makefile.inc b/lib/Makefile.inc index 08b0f73a3..723b826e9 100644 --- a/lib/Makefile.inc +++ b/lib/Makefile.inc @@ -27,14 +27,14 @@ LIB_VAUTH_CFILES = vauth/cleartext.c vauth/cram.c vauth/digest.c \ LIB_VAUTH_HFILES = vauth/digest.h vauth/ntlm.h vauth/vauth.h -LIB_VTLS_CFILES = vtls/bearssl.c vtls/gskit.c vtls/gtls.c vtls/mbedtls.c \ - vtls/mbedtls_threadlock.c vtls/mesalink.c vtls/nss.c vtls/openssl.c \ - vtls/schannel.c vtls/schannel_verify.c vtls/sectransp.c vtls/vtls.c \ - vtls/wolfssl.c +LIB_VTLS_CFILES = vtls/bearssl.c vtls/gskit.c vtls/gtls.c vtls/keylog.c \ + vtls/mbedtls.c vtls/mbedtls_threadlock.c vtls/mesalink.c vtls/nss.c \ + vtls/openssl.c vtls/schannel.c vtls/schannel_verify.c vtls/sectransp.c \ + vtls/vtls.c vtls/wolfssl.c -LIB_VTLS_HFILES = vtls/bearssl.h vtls/gskit.h vtls/gtls.h vtls/mbedtls.h \ - vtls/mbedtls_threadlock.h vtls/mesalink.h vtls/nssg.h vtls/openssl.h \ - vtls/schannel.h vtls/sectransp.h vtls/vtls.h vtls/wolfssl.h +LIB_VTLS_HFILES = vtls/bearssl.h vtls/gskit.h vtls/gtls.h vtls/keylog.h \ + vtls/mbedtls.h vtls/mbedtls_threadlock.h vtls/mesalink.h vtls/nssg.h \ + vtls/openssl.h vtls/schannel.h vtls/sectransp.h vtls/vtls.h vtls/wolfssl.h LIB_VQUIC_CFILES = vquic/ngtcp2.c vquic/quiche.c vquic/vquic.c diff --git a/lib/vtls/keylog.c b/lib/vtls/keylog.c new file mode 100644 index 000000000..70d22ecf0 --- /dev/null +++ b/lib/vtls/keylog.c @@ -0,0 +1,156 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ +#include "curl_setup.h" + +#include "keylog.h" + +/* The last #include files should be: */ +#include "curl_memory.h" +#include "memdebug.h" + +#define KEYLOG_LABEL_MAXLEN (sizeof("CLIENT_HANDSHAKE_TRAFFIC_SECRET") - 1) + +#define CLIENT_RANDOM_SIZE 32 + +/* + * The master secret in TLS 1.2 and before is always 48 bytes. In TLS 1.3, the + * secret size depends on the cipher suite's hash function which is 32 bytes + * for SHA-256 and 48 bytes for SHA-384. + */ +#define SECRET_MAXLEN 48 + + +/* The fp for the open SSLKEYLOGFILE, or NULL if not open */ +static FILE *keylog_file_fp; + +void +Curl_tls_keylog_open(void) +{ + char *keylog_file_name; + + if(!keylog_file_fp) { + keylog_file_name = curl_getenv("SSLKEYLOGFILE"); + if(keylog_file_name) { + keylog_file_fp = fopen(keylog_file_name, FOPEN_APPENDTEXT); + if(keylog_file_fp) { +#ifdef WIN32 + if(setvbuf(keylog_file_fp, NULL, _IONBF, 0)) +#else + if(setvbuf(keylog_file_fp, NULL, _IOLBF, 4096)) +#endif + { + fclose(keylog_file_fp); + keylog_file_fp = NULL; + } + } + Curl_safefree(keylog_file_name); + } + } +} + +void +Curl_tls_keylog_close(void) +{ + if(keylog_file_fp) { + fclose(keylog_file_fp); + keylog_file_fp = NULL; + } +} + +bool +Curl_tls_keylog_enabled(void) +{ + return keylog_file_fp != NULL; +} + +bool +Curl_tls_keylog_write_line(const char *line) +{ + /* The current maximum valid keylog line length LF and NUL is 195. */ + size_t linelen; + char buf[256]; + + if(!keylog_file_fp || !line) { + return false; + } + + linelen = strlen(line); + if(linelen == 0 || linelen > sizeof(buf) - 2) { + /* Empty line or too big to fit in a LF and NUL. */ + return false; + } + + memcpy(buf, line, linelen); + if(line[linelen - 1] != '\n') { + buf[linelen++] = '\n'; + } + buf[linelen] = '\0'; + + /* Using fputs here instead of fprintf since libcurl's fprintf replacement + may not be thread-safe. */ + fputs(buf, keylog_file_fp); + return true; +} + +bool +Curl_tls_keylog_write(const char *label, + const unsigned char client_random[CLIENT_RANDOM_SIZE], + const unsigned char *secret, size_t secretlen) +{ + const char *hex = "0123456789ABCDEF"; + size_t pos, i; + char line[KEYLOG_LABEL_MAXLEN + 1 + 2 * CLIENT_RANDOM_SIZE + 1 + + 2 * SECRET_MAXLEN + 1 + 1]; + + if(!keylog_file_fp) { + return false; + } + + pos = strlen(label); + if(pos > KEYLOG_LABEL_MAXLEN || !secretlen || secretlen > SECRET_MAXLEN) { + /* Should never happen - sanity check anyway. */ + return false; + } + + memcpy(line, label, pos); + line[pos++] = ' '; + + /* Client Random */ + for(i = 0; i < CLIENT_RANDOM_SIZE; i++) { + line[pos++] = hex[client_random[i] >> 4]; + line[pos++] = hex[client_random[i] & 0xF]; + } + line[pos++] = ' '; + + /* Secret */ + for(i = 0; i < secretlen; i++) { + line[pos++] = hex[secret[i] >> 4]; + line[pos++] = hex[secret[i] & 0xF]; + } + line[pos++] = '\n'; + line[pos] = '\0'; + + /* Using fputs here instead of fprintf since libcurl's fprintf replacement + may not be thread-safe. */ + fputs(line, keylog_file_fp); + return true; +} diff --git a/lib/vtls/keylog.h b/lib/vtls/keylog.h new file mode 100644 index 000000000..c6b99db93 --- /dev/null +++ b/lib/vtls/keylog.h @@ -0,0 +1,56 @@ +#ifndef HEADER_CURL_KEYLOG_H +#define HEADER_CURL_KEYLOG_H +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ +#include "curl_setup.h" + +/* + * Opens the TLS key log file if requested by the user. The SSLKEYLOGFILE + * environment variable specifies the output file. + */ +void Curl_tls_keylog_open(void); + +/* + * Closes the TLS key log file if not already. + */ +void Curl_tls_keylog_close(void); + +/* + * Returns true if the user successfully enabled the TLS key log file. + */ +bool Curl_tls_keylog_enabled(void); + +/* + * Appends a key log file entry. + * Returns true iff the key log file is open and a valid entry was provided. + */ +bool Curl_tls_keylog_write(const char *label, + const unsigned char client_random[32], + const unsigned char *secret, size_t secretlen); + +/* + * Appends a line to the key log file, ensure it is terminated by a LF. + * Returns true iff the key log file is open and a valid line was provided. + */ +bool Curl_tls_keylog_write_line(const char *line); + +#endif /* HEADER_CURL_KEYLOG_H */ diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c index e4d50fe08..56920deed 100644 --- a/lib/vtls/openssl.c +++ b/lib/vtls/openssl.c @@ -41,6 +41,7 @@ #include "slist.h" #include "select.h" #include "vtls.h" +#include "keylog.h" #include "strcase.h" #include "hostcheck.h" #include "multiif.h" @@ -212,24 +213,14 @@ "ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH" #endif -#define ENABLE_SSLKEYLOGFILE - -#ifdef ENABLE_SSLKEYLOGFILE -struct ssl_tap_state { - int master_key_length; - unsigned char master_key[SSL_MAX_MASTER_KEY_LENGTH]; - unsigned char client_random[SSL3_RANDOM_SIZE]; -}; -#endif /* ENABLE_SSLKEYLOGFILE */ - struct ssl_backend_data { /* these ones requires specific SSL-types */ SSL_CTX* ctx; SSL* handle; X509* server_cert; -#ifdef ENABLE_SSLKEYLOGFILE - /* tap_state holds the last seen master key if we're logging them */ - struct ssl_tap_state tap_state; +#ifndef HAVE_KEYLOG_CALLBACK + /* Set to true once a valid keylog entry has been created to avoid dupes. */ + bool keylog_done; #endif }; @@ -241,57 +232,27 @@ struct ssl_backend_data { */ #define RAND_LOAD_LENGTH 1024 -#ifdef ENABLE_SSLKEYLOGFILE -/* The fp for the open SSLKEYLOGFILE, or NULL if not open */ -static FILE *keylog_file_fp; - #ifdef HAVE_KEYLOG_CALLBACK static void ossl_keylog_callback(const SSL *ssl, const char *line) { (void)ssl; - /* Using fputs here instead of fprintf since libcurl's fprintf replacement - may not be thread-safe. */ - if(keylog_file_fp && line && *line) { - char stackbuf[256]; - char *buf; - size_t linelen = strlen(line); - - if(linelen <= sizeof(stackbuf) - 2) - buf = stackbuf; - else { - buf = malloc(linelen + 2); - if(!buf) - return; - } - memcpy(buf, line, linelen); - buf[linelen] = '\n'; - buf[linelen + 1] = '\0'; - - fputs(buf, keylog_file_fp); - if(buf != stackbuf) - free(buf); - } + Curl_tls_keylog_write_line(line); } #else -#define KEYLOG_PREFIX "CLIENT_RANDOM " -#define KEYLOG_PREFIX_LEN (sizeof(KEYLOG_PREFIX) - 1) /* - * tap_ssl_key is called by libcurl to make the CLIENT_RANDOMs if the OpenSSL - * being used doesn't have native support for doing that. + * ossl_log_tls12_secret is called by libcurl to make the CLIENT_RANDOMs if the + * OpenSSL being used doesn't have native support for doing that. */ -static void tap_ssl_key(const SSL *ssl, struct ssl_tap_state *state) +static void +ossl_log_tls12_secret(const SSL *ssl, bool *keylog_done) { - const char *hex = "0123456789ABCDEF"; - int pos, i; - char line[KEYLOG_PREFIX_LEN + 2 * SSL3_RANDOM_SIZE + 1 + - 2 * SSL_MAX_MASTER_KEY_LENGTH + 1 + 1]; const SSL_SESSION *session = SSL_get_session(ssl); unsigned char client_random[SSL3_RANDOM_SIZE]; unsigned char master_key[SSL_MAX_MASTER_KEY_LENGTH]; int master_key_length = 0; - if(!session || !keylog_file_fp) + if(!session || *keylog_done) return; #if OPENSSL_VERSION_NUMBER >= 0x10100000L && \ @@ -310,44 +271,17 @@ static void tap_ssl_key(const SSL *ssl, struct ssl_tap_state *state) } #endif + /* The handshake has not progressed sufficiently yet, or this is a TLS 1.3 + * session (when curl was built with older OpenSSL headers and running with + * newer OpenSSL runtime libraries). */ if(master_key_length <= 0) return; - /* Skip writing keys if there is no key or it did not change. */ - if(state->master_key_length == master_key_length && - !memcmp(state->master_key, master_key, master_key_length) && - !memcmp(state->client_random, client_random, SSL3_RANDOM_SIZE)) { - return; - } - - state->master_key_length = master_key_length; - memcpy(state->master_key, master_key, master_key_length); - memcpy(state->client_random, client_random, SSL3_RANDOM_SIZE); - - memcpy(line, KEYLOG_PREFIX, KEYLOG_PREFIX_LEN); - pos = KEYLOG_PREFIX_LEN; - - /* Client Random for SSLv3/TLS */ - for(i = 0; i < SSL3_RANDOM_SIZE; i++) { - line[pos++] = hex[client_random[i] >> 4]; - line[pos++] = hex[client_random[i] & 0xF]; - } - line[pos++] = ' '; - - /* Master Secret (size is at most SSL_MAX_MASTER_KEY_LENGTH) */ - for(i = 0; i < master_key_length; i++) { - line[pos++] = hex[master_key[i] >> 4]; - line[pos++] = hex[master_key[i] & 0xF]; - } - line[pos++] = '\n'; - line[pos] = '\0'; - - /* Using fputs here instead of fprintf since libcurl's fprintf replacement - may not be thread-safe. */ - fputs(line, keylog_file_fp); + *keylog_done = true; + Curl_tls_keylog_write("CLIENT_RANDOM", client_random, + master_key, master_key_length); } #endif /* !HAVE_KEYLOG_CALLBACK */ -#endif /* ENABLE_SSLKEYLOGFILE */ static const char *SSL_ERROR_to_str(int err) { @@ -1163,10 +1097,6 @@ static int x509_name_oneline(X509_NAME *a, char *buf, size_t size) */ static int Curl_ossl_init(void) { -#ifdef ENABLE_SSLKEYLOGFILE - char *keylog_file_name; -#endif - OPENSSL_load_builtin_modules(); #ifdef USE_OPENSSL_ENGINE @@ -1199,26 +1129,7 @@ static int Curl_ossl_init(void) OpenSSL_add_all_algorithms(); #endif -#ifdef ENABLE_SSLKEYLOGFILE - if(!keylog_file_fp) { - keylog_file_name = curl_getenv("SSLKEYLOGFILE"); - if(keylog_file_name) { - keylog_file_fp = fopen(keylog_file_name, FOPEN_APPENDTEXT); - if(keylog_file_fp) { -#ifdef WIN32 - if(setvbuf(keylog_file_fp, NULL, _IONBF, 0)) -#else - if(setvbuf(keylog_file_fp, NULL, _IOLBF, 4096)) -#endif - { - fclose(keylog_file_fp); - keylog_file_fp = NULL; - } - } - Curl_safefree(keylog_file_name); - } - } -#endif + Curl_tls_keylog_open(); /* Initialize the extra data indexes */ if(ossl_get_ssl_conn_index() < 0 || ossl_get_ssl_sockindex_index() < 0) @@ -1261,12 +1172,7 @@ static void Curl_ossl_cleanup(void) #endif #endif -#ifdef ENABLE_SSLKEYLOGFILE - if(keylog_file_fp) { - fclose(keylog_file_fp); - keylog_file_fp = NULL; - } -#endif + Curl_tls_keylog_close(); } /* @@ -3159,8 +3065,8 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex) verifypeer ? SSL_VERIFY_PEER : SSL_VERIFY_NONE, NULL); /* Enable logging of secrets to the file specified in env SSLKEYLOGFILE. */ -#if defined(ENABLE_SSLKEYLOGFILE) && defined(HAVE_KEYLOG_CALLBACK) - if(keylog_file_fp) { +#ifdef HAVE_KEYLOG_CALLBACK + if(Curl_tls_keylog_enabled()) { SSL_CTX_set_keylog_callback(backend->ctx, ossl_keylog_callback); } #endif @@ -3283,10 +3189,13 @@ static CURLcode ossl_connect_step2(struct connectdata *conn, int sockindex) ERR_clear_error(); err = SSL_connect(backend->handle); - /* If keylogging is enabled but the keylog callback is not supported then log - secrets here, immediately after SSL_connect by using tap_ssl_key. */ -#if defined(ENABLE_SSLKEYLOGFILE) && !defined(HAVE_KEYLOG_CALLBACK) - tap_ssl_key(backend->handle, &backend->tap_state); +#ifndef HAVE_KEYLOG_CALLBACK + if(Curl_tls_keylog_enabled()) { + /* If key logging is enabled, wait for the handshake to complete and then + * proceed with logging secrets (for TLS 1.2 or older). + */ + ossl_log_tls12_secret(backend->handle, &backend->keylog_done); + } #endif /* 1 is fine |