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Diffstat (limited to '')
| -rw-r--r-- | src/tls/tls_misc.c | 1566 |
1 files changed, 1566 insertions, 0 deletions
diff --git a/src/tls/tls_misc.c b/src/tls/tls_misc.c new file mode 100644 index 0000000..c2b1121 --- /dev/null +++ b/src/tls/tls_misc.c @@ -0,0 +1,1566 @@ +/*++ +/* NAME +/* tls_misc 3 +/* SUMMARY +/* miscellaneous TLS support routines +/* SYNOPSIS +/* .SH Public functions +/* .nf +/* .na +/* #include <tls.h> +/* +/* void tls_log_summary(role, usage, TLScontext) +/* TLS_ROLE role; +/* TLS_USAGE usage; +/* TLS_SESS_STATE *TLScontext; +/* +/* const char *tls_compile_version(void) +/* +/* const char *tls_run_version(void) +/* +/* const char **tls_pkey_algorithms(void) +/* +/* void tls_pre_jail_init(TLS_ROLE) +/* TLS_ROLE role; +/* +/* .SH Internal functions +/* .nf +/* .na +/* #define TLS_INTERNAL +/* #include <tls.h> +/* +/* char *var_tls_high_clist; +/* char *var_tls_medium_clist; +/* char *var_tls_low_clist; +/* char *var_tls_export_clist; +/* char *var_tls_null_clist; +/* char *var_tls_eecdh_auto; +/* char *var_tls_eecdh_strong; +/* char *var_tls_eecdh_ultra; +/* char *var_tls_dane_digests; +/* int var_tls_daemon_rand_bytes; +/* bool var_tls_append_def_CA; +/* bool var_tls_preempt_clist; +/* bool var_tls_bc_pkey_fprint; +/* bool var_tls_multi_wildcard; +/* char *var_tls_mgr_service; +/* char *var_tls_tkt_cipher; +/* char *var_openssl_path; +/* char *var_tls_server_sni_maps; +/* bool var_tls_fast_shutdown; +/* +/* TLS_APPL_STATE *tls_alloc_app_context(ssl_ctx, log_mask) +/* SSL_CTX *ssl_ctx; +/* int log_mask; +/* +/* void tls_free_app_context(app_ctx) +/* void *app_ctx; +/* +/* TLS_SESS_STATE *tls_alloc_sess_context(log_mask, namaddr) +/* int log_mask; +/* const char *namaddr; +/* +/* void tls_free_context(TLScontext) +/* TLS_SESS_STATE *TLScontext; +/* +/* void tls_check_version() +/* +/* long tls_bug_bits() +/* +/* void tls_param_init() +/* +/* int tls_protocol_mask(plist) +/* const char *plist; +/* +/* int tls_cipher_grade(name) +/* const char *name; +/* +/* const char *str_tls_cipher_grade(grade) +/* int grade; +/* +/* const char *tls_set_ciphers(TLScontext, grade, exclusions) +/* TLS_SESS_STATE *TLScontext; +/* int grade; +/* const char *exclusions; +/* +/* void tls_get_signature_params(TLScontext) +/* TLS_SESS_STATE *TLScontext; +/* +/* void tls_print_errors() +/* +/* void tls_info_callback(ssl, where, ret) +/* const SSL *ssl; /* unused */ +/* int where; +/* int ret; +/* +/* long tls_bio_dump_cb(bio, cmd, argp, argi, argl, ret) +/* BIO *bio; +/* int cmd; +/* const char *argp; +/* int argi; +/* long argl; /* unused */ +/* long ret; +/* +/* int tls_log_mask(log_param, log_level) +/* const char *log_param; +/* const char *log_level; +/* +/* void tls_update_app_logmask(app_ctx, log_mask) +/* TLS_APPL_STATE *app_ctx; +/* int log_mask; +/* +/* int tls_validate_digest(dgst) +/* const char *dgst; +/* DESCRIPTION +/* This module implements public and internal routines that +/* support the TLS client and server. +/* +/* tls_log_summary() logs a summary of a completed TLS connection. +/* The "role" argument must be TLS_ROLE_CLIENT for outgoing client +/* connections, or TLS_ROLE_SERVER for incoming server connections, +/* and the "usage" must be TLS_USAGE_NEW or TLS_USAGE_USED. +/* +/* tls_compile_version() returns a text string description of +/* the compile-time TLS library. +/* +/* tls_run_version() is just tls_compile_version() but with the runtime +/* version instead of the compile-time version. +/* +/* tls_pkey_algorithms() returns a pointer to null-terminated +/* array of string constants with the names of the supported +/* public-key algorithms. +/* +/* tls_alloc_app_context() creates an application context that +/* holds the SSL context for the application and related cached state. +/* +/* tls_free_app_context() deallocates the application context and its +/* contents (the application context is stored outside the TLS library). +/* +/* tls_alloc_sess_context() creates an initialized TLS session context +/* structure with the specified log mask and peer name[addr]. +/* +/* tls_free_context() destroys a TLScontext structure +/* together with OpenSSL structures that are attached to it. +/* +/* tls_check_version() logs a warning when the run-time OpenSSL +/* library differs in its major, minor or micro number from +/* the compile-time OpenSSL headers. +/* +/* tls_bug_bits() returns the bug compatibility mask appropriate +/* for the run-time library. Some of the bug work-arounds are +/* not appropriate for some library versions. +/* +/* tls_param_init() loads main.cf parameters used internally in +/* TLS library. Any errors are fatal. +/* +/* tls_pre_jail_init() opens any tables that need to be opened before +/* entering a chroot jail. The "role" parameter must be TLS_ROLE_CLIENT +/* for clients and TLS_ROLE_SERVER for servers. Any errors are fatal. +/* +/* tls_protocol_mask() returns a bitmask of excluded protocols, given +/* a list (plist) of protocols to include or (preceded by a '!') exclude. +/* If "plist" contains invalid protocol names, TLS_PROTOCOL_INVALID is +/* returned and no warning is logged. +/* +/* tls_cipher_grade() converts a case-insensitive cipher grade +/* name (high, medium, low, export, null) to the corresponding +/* TLS_CIPHER_ constant. When the input specifies an unrecognized +/* grade, tls_cipher_grade() logs no warning, and returns +/* TLS_CIPHER_NONE. +/* +/* str_tls_cipher_grade() converts a cipher grade to a name. +/* When the input specifies an undefined grade, str_tls_cipher_grade() +/* logs no warning, returns a null pointer. +/* +/* tls_set_ciphers() applies the requested cipher grade and exclusions +/* to the provided TLS session context, returning the resulting cipher +/* list string. The return value is the cipherlist used and is +/* overwritten upon each call. When the input is invalid, +/* tls_set_ciphers() logs a warning, and returns a null result. +/* +/* tls_get_signature_params() updates the "TLScontext" with handshake +/* signature parameters pertaining to TLS 1.3, where the ciphersuite +/* no longer describes the asymmetric algorithms employed in the +/* handshake, which are negotiated separately. This function +/* has no effect for TLS 1.2 and earlier. +/* +/* tls_print_errors() queries the OpenSSL error stack, +/* logs the error messages, and clears the error stack. +/* +/* tls_info_callback() is a call-back routine for the +/* SSL_CTX_set_info_callback() routine. It logs SSL events +/* to the Postfix logfile. +/* +/* tls_bio_dump_cb() is a call-back routine for the +/* BIO_set_callback() routine. It logs SSL content to the +/* Postfix logfile. +/* +/* tls_log_mask() converts a TLS log_level value from string +/* to mask. The main.cf parameter name is passed along for +/* diagnostics. +/* +/* tls_update_app_logmask() changes the log mask of the +/* application TLS context to the new setting. +/* +/* tls_validate_digest() returns non-zero if the named digest +/* is usable and zero otherwise. +/* LICENSE +/* .ad +/* .fi +/* This software is free. You can do with it whatever you want. +/* The original author kindly requests that you acknowledge +/* the use of his software. +/* AUTHOR(S) +/* Originally written by: +/* Lutz Jaenicke +/* BTU Cottbus +/* Allgemeine Elektrotechnik +/* Universitaetsplatz 3-4 +/* D-03044 Cottbus, Germany +/* +/* Updated by: +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Victor Duchovni +/* Morgan Stanley +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <ctype.h> +#include <string.h> + +#ifdef USE_TLS + +/* Utility library. */ + +#include <vstream.h> +#include <msg.h> +#include <mymalloc.h> +#include <vstring.h> +#include <stringops.h> +#include <argv.h> +#include <name_mask.h> +#include <name_code.h> +#include <dict.h> +#include <valid_hostname.h> + + /* + * Global library. + */ +#include <mail_params.h> +#include <mail_conf.h> +#include <maps.h> + + /* + * TLS library. + */ +#define TLS_INTERNAL +#include <tls.h> + + /* Application-specific. */ + + /* + * Tunable parameters. + */ +char *var_tls_high_clist; +char *var_tls_medium_clist; +char *var_tls_low_clist; +char *var_tls_export_clist; +char *var_tls_null_clist; +int var_tls_daemon_rand_bytes; +char *var_tls_eecdh_auto; +char *var_tls_eecdh_strong; +char *var_tls_eecdh_ultra; +char *var_tls_dane_digests; +bool var_tls_append_def_CA; +char *var_tls_bug_tweaks; +char *var_tls_ssl_options; +bool var_tls_bc_pkey_fprint; +bool var_tls_multi_wildcard; +char *var_tls_mgr_service; +char *var_tls_tkt_cipher; +char *var_openssl_path; +char *var_tls_server_sni_maps; +bool var_tls_fast_shutdown; + +static MAPS *tls_server_sni_maps; + +#ifdef VAR_TLS_PREEMPT_CLIST +bool var_tls_preempt_clist; + +#endif + + /* + * Index to attach TLScontext pointers to SSL objects, so that they can be + * accessed by call-back routines. + */ +int TLScontext_index = -1; + + /* + * Protocol name <=> mask conversion. + */ +static const NAME_CODE protocol_table[] = { + SSL_TXT_SSLV2, TLS_PROTOCOL_SSLv2, + SSL_TXT_SSLV3, TLS_PROTOCOL_SSLv3, + SSL_TXT_TLSV1, TLS_PROTOCOL_TLSv1, + SSL_TXT_TLSV1_1, TLS_PROTOCOL_TLSv1_1, + SSL_TXT_TLSV1_2, TLS_PROTOCOL_TLSv1_2, + TLS_PROTOCOL_TXT_TLSV1_3, TLS_PROTOCOL_TLSv1_3, + 0, TLS_PROTOCOL_INVALID, +}; + + /* + * SSL_OP_MUMBLE bug work-around name <=> mask conversion. + */ +#define NAMEBUG(x) #x, SSL_OP_##x +static const LONG_NAME_MASK ssl_bug_tweaks[] = { + +#ifndef SSL_OP_MICROSOFT_SESS_ID_BUG +#define SSL_OP_MICROSOFT_SESS_ID_BUG 0 +#endif + NAMEBUG(MICROSOFT_SESS_ID_BUG), + +#ifndef SSL_OP_NETSCAPE_CHALLENGE_BUG +#define SSL_OP_NETSCAPE_CHALLENGE_BUG 0 +#endif + NAMEBUG(NETSCAPE_CHALLENGE_BUG), + +#ifndef SSL_OP_LEGACY_SERVER_CONNECT +#define SSL_OP_LEGACY_SERVER_CONNECT 0 +#endif + NAMEBUG(LEGACY_SERVER_CONNECT), + +#ifndef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG +#define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0 +#endif + NAMEBUG(NETSCAPE_REUSE_CIPHER_CHANGE_BUG), + "CVE-2010-4180", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG, + +#ifndef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG +#define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0 +#endif + NAMEBUG(SSLREF2_REUSE_CERT_TYPE_BUG), + +#ifndef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER +#define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0 +#endif + NAMEBUG(MICROSOFT_BIG_SSLV3_BUFFER), + +#ifndef SSL_OP_MSIE_SSLV2_RSA_PADDING +#define SSL_OP_MSIE_SSLV2_RSA_PADDING 0 +#endif + NAMEBUG(MSIE_SSLV2_RSA_PADDING), + "CVE-2005-2969", SSL_OP_MSIE_SSLV2_RSA_PADDING, + +#ifndef SSL_OP_SSLEAY_080_CLIENT_DH_BUG +#define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0 +#endif + NAMEBUG(SSLEAY_080_CLIENT_DH_BUG), + +#ifndef SSL_OP_TLS_D5_BUG +#define SSL_OP_TLS_D5_BUG 0 +#endif + NAMEBUG(TLS_D5_BUG), + +#ifndef SSL_OP_TLS_BLOCK_PADDING_BUG +#define SSL_OP_TLS_BLOCK_PADDING_BUG 0 +#endif + NAMEBUG(TLS_BLOCK_PADDING_BUG), + +#ifndef SSL_OP_TLS_ROLLBACK_BUG +#define SSL_OP_TLS_ROLLBACK_BUG 0 +#endif + NAMEBUG(TLS_ROLLBACK_BUG), + +#ifndef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS +#define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0 +#endif + NAMEBUG(DONT_INSERT_EMPTY_FRAGMENTS), + +#ifndef SSL_OP_CRYPTOPRO_TLSEXT_BUG +#define SSL_OP_CRYPTOPRO_TLSEXT_BUG 0 +#endif + NAMEBUG(CRYPTOPRO_TLSEXT_BUG), + +#ifndef SSL_OP_TLSEXT_PADDING +#define SSL_OP_TLSEXT_PADDING 0 +#endif + NAMEBUG(TLSEXT_PADDING), + +#if 0 + + /* + * XXX: New with OpenSSL 1.1.1, this is turned on implicitly in + * SSL_CTX_new() and is not included in SSL_OP_ALL. Allowing users to + * disable this would thus be a code change that would require clearing + * bug work-around bits in SSL_CTX, after setting SSL_OP_ALL. Since this + * is presumably required for TLS 1.3 on today's Internet, the code + * change will be done separately later. For now this implicit bug + * work-around cannot be disabled via supported Postfix mechanisms. + */ +#ifndef SSL_OP_ENABLE_MIDDLEBOX_COMPAT +#define SSL_OP_ENABLE_MIDDLEBOX_COMPAT 0 +#endif + NAMEBUG(ENABLE_MIDDLEBOX_COMPAT), +#endif + + 0, 0, +}; + + /* + * SSL_OP_MUMBLE option name <=> mask conversion for options that are not + * (or may in the future not be) in SSL_OP_ALL. These enable optional + * behavior, rather than bug interoperability work-arounds. + */ +#define NAME_SSL_OP(x) #x, SSL_OP_##x +static const LONG_NAME_MASK ssl_op_tweaks[] = { + +#ifndef SSL_OP_LEGACY_SERVER_CONNECT +#define SSL_OP_LEGACY_SERVER_CONNECT 0 +#endif + NAME_SSL_OP(LEGACY_SERVER_CONNECT), + +#ifndef SSL_OP_NO_TICKET +#define SSL_OP_NO_TICKET 0 +#endif + NAME_SSL_OP(NO_TICKET), + +#ifndef SSL_OP_NO_COMPRESSION +#define SSL_OP_NO_COMPRESSION 0 +#endif + NAME_SSL_OP(NO_COMPRESSION), + +#ifndef SSL_OP_NO_RENEGOTIATION +#define SSL_OP_NO_RENEGOTIATION 0 +#endif + NAME_SSL_OP(NO_RENEGOTIATION), + +#ifndef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION +#define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0 +#endif + NAME_SSL_OP(NO_SESSION_RESUMPTION_ON_RENEGOTIATION), + +#ifndef SSL_OP_PRIORITIZE_CHACHA +#define SSL_OP_PRIORITIZE_CHACHA 0 +#endif + NAME_SSL_OP(PRIORITIZE_CHACHA), + +#ifndef SSL_OP_ENABLE_MIDDLEBOX_COMPAT +#define SSL_OP_ENABLE_MIDDLEBOX_COMPAT 0 +#endif + NAME_SSL_OP(ENABLE_MIDDLEBOX_COMPAT), + + 0, 0, +}; + + /* + * Once these have been a NOOP long enough, they might some day be removed + * from OpenSSL. The defines below will avoid bitrot issues if/when that + * happens. + */ +#ifndef SSL_OP_SINGLE_DH_USE +#define SSL_OP_SINGLE_DH_USE 0 +#endif +#ifndef SSL_OP_SINGLE_ECDH_USE +#define SSL_OP_SINGLE_ECDH_USE 0 +#endif + + /* + * Ciphersuite name <=> code conversion. + */ +const NAME_CODE tls_cipher_grade_table[] = { + "high", TLS_CIPHER_HIGH, + "medium", TLS_CIPHER_MEDIUM, + "low", TLS_CIPHER_LOW, + "export", TLS_CIPHER_EXPORT, + "null", TLS_CIPHER_NULL, + "invalid", TLS_CIPHER_NONE, + 0, TLS_CIPHER_NONE, +}; + + /* + * Log keyword <=> mask conversion. + */ +#define TLS_LOG_0 TLS_LOG_NONE +#define TLS_LOG_1 TLS_LOG_SUMMARY +#define TLS_LOG_2 (TLS_LOG_1 | TLS_LOG_VERBOSE | TLS_LOG_CACHE | TLS_LOG_DEBUG) +#define TLS_LOG_3 (TLS_LOG_2 | TLS_LOG_TLSPKTS) +#define TLS_LOG_4 (TLS_LOG_3 | TLS_LOG_ALLPKTS) + +static const NAME_MASK tls_log_table[] = { + "0", TLS_LOG_0, + "none", TLS_LOG_NONE, + "1", TLS_LOG_1, + "routine", TLS_LOG_1, + "2", TLS_LOG_2, + "debug", TLS_LOG_2, + "3", TLS_LOG_3, + "ssl-expert", TLS_LOG_3, + "4", TLS_LOG_4, + "ssl-developer", TLS_LOG_4, + "5", TLS_LOG_4, /* for good measure */ + "6", TLS_LOG_4, /* for good measure */ + "7", TLS_LOG_4, /* for good measure */ + "8", TLS_LOG_4, /* for good measure */ + "9", TLS_LOG_4, /* for good measure */ + "summary", TLS_LOG_SUMMARY, + "untrusted", TLS_LOG_UNTRUSTED, + "peercert", TLS_LOG_PEERCERT, + "certmatch", TLS_LOG_CERTMATCH, + "verbose", TLS_LOG_VERBOSE, /* Postfix TLS library verbose */ + "cache", TLS_LOG_CACHE, + "ssl-debug", TLS_LOG_DEBUG, /* SSL library debug/verbose */ + "ssl-handshake-packet-dump", TLS_LOG_TLSPKTS, + "ssl-session-packet-dump", TLS_LOG_TLSPKTS | TLS_LOG_ALLPKTS, + 0, 0, +}; + + /* + * Parsed OpenSSL version number. + */ +typedef struct { + int major; + int minor; + int micro; + int patch; + int status; +} TLS_VINFO; + +/* tls_log_mask - Convert user TLS loglevel to internal log feature mask */ + +int tls_log_mask(const char *log_param, const char *log_level) +{ + int mask; + + mask = name_mask_opt(log_param, tls_log_table, log_level, + NAME_MASK_ANY_CASE | NAME_MASK_RETURN); + return (mask); +} + +/* tls_update_app_logmask - update log level after init */ + +void tls_update_app_logmask(TLS_APPL_STATE *app_ctx, int log_mask) +{ + app_ctx->log_mask = log_mask; +} + +/* tls_protocol_mask - Bitmask of protocols to exclude */ + +int tls_protocol_mask(const char *plist) +{ + char *save; + char *tok; + char *cp; + int code; + int exclude = 0; + int include = 0; + +#define FREE_AND_RETURN(ptr, res) do { \ + myfree(ptr); \ + return (res); \ + } while (0) + + save = cp = mystrdup(plist); + while ((tok = mystrtok(&cp, CHARS_COMMA_SP ":")) != 0) { + if (*tok == '!') + exclude |= code = + name_code(protocol_table, NAME_CODE_FLAG_NONE, ++tok); + else + include |= code = + name_code(protocol_table, NAME_CODE_FLAG_NONE, tok); + if (code == TLS_PROTOCOL_INVALID) + FREE_AND_RETURN(save, TLS_PROTOCOL_INVALID); + } + + /* + * When the include list is empty, use only the explicit exclusions. + * Otherwise, also exclude the complement of the include list from the + * built-in list of known protocols. There is no way to exclude protocols + * we don't know about at compile time, and this is unavoidable because + * the OpenSSL API works with compile-time *exclusion* bit-masks. + */ + FREE_AND_RETURN(save, + (include ? (exclude | (TLS_KNOWN_PROTOCOLS & ~include)) : exclude)); +} + +/* tls_param_init - Load TLS related config parameters */ + +void tls_param_init(void) +{ + /* If this changes, update TLS_CLIENT_PARAMS in tls_proxy.h. */ + static const CONFIG_STR_TABLE str_table[] = { + VAR_TLS_HIGH_CLIST, DEF_TLS_HIGH_CLIST, &var_tls_high_clist, 1, 0, + VAR_TLS_MEDIUM_CLIST, DEF_TLS_MEDIUM_CLIST, &var_tls_medium_clist, 1, 0, + VAR_TLS_LOW_CLIST, DEF_TLS_LOW_CLIST, &var_tls_low_clist, 1, 0, + VAR_TLS_EXPORT_CLIST, DEF_TLS_EXPORT_CLIST, &var_tls_export_clist, 1, 0, + VAR_TLS_NULL_CLIST, DEF_TLS_NULL_CLIST, &var_tls_null_clist, 1, 0, + VAR_TLS_EECDH_AUTO, DEF_TLS_EECDH_AUTO, &var_tls_eecdh_auto, 1, 0, + VAR_TLS_EECDH_STRONG, DEF_TLS_EECDH_STRONG, &var_tls_eecdh_strong, 1, 0, + VAR_TLS_EECDH_ULTRA, DEF_TLS_EECDH_ULTRA, &var_tls_eecdh_ultra, 1, 0, + VAR_TLS_BUG_TWEAKS, DEF_TLS_BUG_TWEAKS, &var_tls_bug_tweaks, 0, 0, + VAR_TLS_SSL_OPTIONS, DEF_TLS_SSL_OPTIONS, &var_tls_ssl_options, 0, 0, + VAR_TLS_DANE_DIGESTS, DEF_TLS_DANE_DIGESTS, &var_tls_dane_digests, 1, 0, + VAR_TLS_MGR_SERVICE, DEF_TLS_MGR_SERVICE, &var_tls_mgr_service, 1, 0, + VAR_TLS_TKT_CIPHER, DEF_TLS_TKT_CIPHER, &var_tls_tkt_cipher, 0, 0, + VAR_OPENSSL_PATH, DEF_OPENSSL_PATH, &var_openssl_path, 1, 0, + 0, + }; + + /* If this changes, update TLS_CLIENT_PARAMS in tls_proxy.h. */ + static const CONFIG_INT_TABLE int_table[] = { + VAR_TLS_DAEMON_RAND_BYTES, DEF_TLS_DAEMON_RAND_BYTES, &var_tls_daemon_rand_bytes, 1, 0, + 0, + }; + + /* If this changes, update TLS_CLIENT_PARAMS in tls_proxy.h. */ + static const CONFIG_BOOL_TABLE bool_table[] = { + VAR_TLS_APPEND_DEF_CA, DEF_TLS_APPEND_DEF_CA, &var_tls_append_def_CA, + VAR_TLS_BC_PKEY_FPRINT, DEF_TLS_BC_PKEY_FPRINT, &var_tls_bc_pkey_fprint, + VAR_TLS_PREEMPT_CLIST, DEF_TLS_PREEMPT_CLIST, &var_tls_preempt_clist, + VAR_TLS_MULTI_WILDCARD, DEF_TLS_MULTI_WILDCARD, &var_tls_multi_wildcard, + VAR_TLS_FAST_SHUTDOWN, DEF_TLS_FAST_SHUTDOWN, &var_tls_fast_shutdown, + 0, + }; + static int init_done; + + if (init_done) + return; + init_done = 1; + + get_mail_conf_str_table(str_table); + get_mail_conf_int_table(int_table); + get_mail_conf_bool_table(bool_table); +} + +/* tls_pre_jail_init - Load TLS related pre-jail tables */ + +void tls_pre_jail_init(TLS_ROLE role) +{ + static const CONFIG_STR_TABLE str_table[] = { + VAR_TLS_SERVER_SNI_MAPS, DEF_TLS_SERVER_SNI_MAPS, &var_tls_server_sni_maps, 0, 0, + 0, + }; + int flags; + + tls_param_init(); + + /* Nothing for clients at this time */ + if (role != TLS_ROLE_SERVER) + return; + + get_mail_conf_str_table(str_table); + if (*var_tls_server_sni_maps == 0) + return; + + flags = DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX | DICT_FLAG_SRC_RHS_IS_FILE; + tls_server_sni_maps = + maps_create(VAR_TLS_SERVER_SNI_MAPS, var_tls_server_sni_maps, flags); +} + +/* server_sni_callback - process client's SNI extension */ + +static int server_sni_callback(SSL *ssl, int *alert, void *arg) +{ + SSL_CTX *sni_ctx = (SSL_CTX *) arg; + TLS_SESS_STATE *TLScontext = SSL_get_ex_data(ssl, TLScontext_index); + const char *sni = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name); + const char *cp = sni; + const char *pem; + + /* SNI is silently ignored when we don't care or is NULL or empty */ + if (!sni_ctx || !tls_server_sni_maps || !sni || !*sni) + return SSL_TLSEXT_ERR_NOACK; + + if (!valid_hostname(sni, DONT_GRIPE)) { + msg_warn("TLS SNI from %s is invalid: %s", + TLScontext->namaddr, sni); + return SSL_TLSEXT_ERR_NOACK; + } + + /* + * With TLS 1.3, when the client's proposed key share is not supported by + * the server, the server may issue a HelloRetryRequest (HRR), and the + * client will then retry with a new key share on a curve supported by + * the server. This results in the SNI callback running twice for the + * same connection. + * + * When that happens, The client MUST send the essentially the same hello + * message, including the SNI name, and since we've already loaded our + * certificate chain, we don't need to do it again! Therefore, if we've + * already recorded the peer SNI name, just check that it has not + * changed, and return success. + */ + if (TLScontext->peer_sni) { + if (strcmp(sni, TLScontext->peer_sni) == 0) + return SSL_TLSEXT_ERR_OK; + msg_warn("TLS SNI changed from %s initially %s, %s after hello retry", + TLScontext->namaddr, TLScontext->peer_sni, sni); + return SSL_TLSEXT_ERR_NOACK; + } + do { + /* Don't silently skip maps opened with the wrong flags. */ + pem = maps_file_find(tls_server_sni_maps, cp, 0); + } while (!pem + && !tls_server_sni_maps->error + && (cp = strchr(cp + 1, '.')) != 0); + + if (!pem) { + if (tls_server_sni_maps->error) { + msg_warn("%s: %s map lookup problem", + tls_server_sni_maps->title, sni); + *alert = SSL_AD_INTERNAL_ERROR; + return SSL_TLSEXT_ERR_ALERT_FATAL; + } + msg_info("TLS SNI %s from %s not matched, using default chain", + sni, TLScontext->namaddr); + + /* + * XXX: We could lie and pretend to accept the name, but since we've + * previously not implemented the callback (with OpenSSL then + * declining the extension), and nothing bad happened, declining it + * explicitly should be safe. + */ + return SSL_TLSEXT_ERR_NOACK; + } + SSL_set_SSL_CTX(ssl, sni_ctx); + if (tls_load_pem_chain(ssl, pem, sni) != 0) { + /* errors already logged */ + *alert = SSL_AD_INTERNAL_ERROR; + return SSL_TLSEXT_ERR_ALERT_FATAL; + } + TLScontext->peer_sni = mystrdup(sni); + return SSL_TLSEXT_ERR_OK; +} + +/* tls_set_ciphers - Set SSL context cipher list */ + +const char *tls_set_ciphers(TLS_SESS_STATE *TLScontext, const char *grade, + const char *exclusions) +{ + const char *myname = "tls_set_ciphers"; + static VSTRING *buf; + char *save; + char *cp; + char *tok; + + if (buf == 0) + buf = vstring_alloc(10); + VSTRING_RESET(buf); + + switch (tls_cipher_grade(grade)) { + case TLS_CIPHER_NONE: + msg_warn("%s: invalid cipher grade: \"%s\"", + TLScontext->namaddr, grade); + return (0); + case TLS_CIPHER_HIGH: + vstring_strcpy(buf, var_tls_high_clist); + break; + case TLS_CIPHER_MEDIUM: + vstring_strcpy(buf, var_tls_medium_clist); + break; + case TLS_CIPHER_LOW: + vstring_strcpy(buf, var_tls_low_clist); + break; + case TLS_CIPHER_EXPORT: + vstring_strcpy(buf, var_tls_export_clist); + break; + case TLS_CIPHER_NULL: + vstring_strcpy(buf, var_tls_null_clist); + break; + default: + /* Internal error, valid grade, but missing case label. */ + msg_panic("%s: unexpected cipher grade: %s", myname, grade); + } + + /* + * The base lists for each grade can't be empty. + */ + if (VSTRING_LEN(buf) == 0) + msg_panic("%s: empty \"%s\" cipherlist", myname, grade); + + /* + * Apply locally-specified exclusions. + */ +#define CIPHER_SEP CHARS_COMMA_SP ":" + if (exclusions != 0) { + cp = save = mystrdup(exclusions); + while ((tok = mystrtok(&cp, CIPHER_SEP)) != 0) { + + /* + * Can't exclude ciphers that start with modifiers. + */ + if (strchr("!+-@", *tok)) { + msg_warn("%s: invalid unary '!+-@' in cipher exclusion: %s", + TLScontext->namaddr, tok); + return (0); + } + vstring_sprintf_append(buf, ":!%s", tok); + } + myfree(save); + } + ERR_clear_error(); + if (SSL_set_cipher_list(TLScontext->con, vstring_str(buf)) == 0) { + msg_warn("%s: error setting cipher grade: \"%s\"", + TLScontext->namaddr, grade); + tls_print_errors(); + return (0); + } + return (vstring_str(buf)); +} + +/* tls_get_signature_params - TLS 1.3 signature details */ + +void tls_get_signature_params(TLS_SESS_STATE *TLScontext) +{ +#if OPENSSL_VERSION_NUMBER >= 0x1010100fUL && defined(TLS1_3_VERSION) + const char *kex_name = 0; + const char *kex_curve = 0; + const char *locl_sig_name = 0; + const char *locl_sig_curve = 0; + const char *locl_sig_dgst = 0; + const char *peer_sig_name = 0; + const char *peer_sig_curve = 0; + const char *peer_sig_dgst = 0; + int nid; + int got_kex_key; + SSL *ssl = TLScontext->con; + int srvr = SSL_is_server(ssl); + X509 *cert; + EVP_PKEY *pkey = 0; + +#ifndef OPENSSL_NO_EC + const EC_KEY *eckey; + +#endif + +#define SIG_PROP(c, s, p) (*((s) ? &c->srvr_sig_##p : &c->clnt_sig_##p)) + + if (SSL_version(ssl) < TLS1_3_VERSION) + return; + + if (tls_get_peer_dh_pubkey(ssl, &pkey)) { + switch (nid = EVP_PKEY_id(pkey)) { + default: + kex_name = OBJ_nid2sn(EVP_PKEY_type(nid)); + break; + + case EVP_PKEY_DH: + kex_name = "DHE"; + TLScontext->kex_bits = EVP_PKEY_bits(pkey); + break; + +#ifndef OPENSSL_NO_EC + case EVP_PKEY_EC: + kex_name = "ECDHE"; + eckey = EVP_PKEY_get0_EC_KEY(pkey); + nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(eckey)); + kex_curve = EC_curve_nid2nist(nid); + if (!kex_curve) + kex_curve = OBJ_nid2sn(nid); + break; +#endif + } + EVP_PKEY_free(pkey); + } + + /* + * On the client end, the certificate may be preset, but not used, so we + * check via SSL_get_signature_nid(). This means that local signature + * data on clients requires at least 1.1.1a. + */ + if (srvr || SSL_get_signature_nid(ssl, &nid)) + cert = SSL_get_certificate(ssl); + else + cert = 0; + + /* Signature algorithms for the local end of the connection */ + if (cert) { + pkey = X509_get0_pubkey(cert); + + /* + * Override the built-in name for the "ECDSA" algorithms OID, with + * the more familiar name. For "RSA" keys report "RSA-PSS", which + * must be used with TLS 1.3. + */ + if ((nid = EVP_PKEY_type(EVP_PKEY_id(pkey))) != NID_undef) { + switch (nid) { + default: + locl_sig_name = OBJ_nid2sn(nid); + break; + + case EVP_PKEY_RSA: + /* For RSA, TLS 1.3 mandates PSS signatures */ + locl_sig_name = "RSA-PSS"; + SIG_PROP(TLScontext, srvr, bits) = EVP_PKEY_bits(pkey); + break; + +#ifndef OPENSSL_NO_EC + case EVP_PKEY_EC: + locl_sig_name = "ECDSA"; + eckey = EVP_PKEY_get0_EC_KEY(pkey); + nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(eckey)); + locl_sig_curve = EC_curve_nid2nist(nid); + if (!locl_sig_curve) + locl_sig_curve = OBJ_nid2sn(nid); + break; +#endif + } + } + + /* + * With Ed25519 and Ed448 there is no pre-signature digest, but the + * accessor does not fail, rather we get NID_undef. + */ + if (SSL_get_signature_nid(ssl, &nid) && nid != NID_undef) + locl_sig_dgst = OBJ_nid2sn(nid); + } + /* Signature algorithms for the peer end of the connection */ + if ((cert = SSL_get_peer_certificate(ssl)) != 0) { + pkey = X509_get0_pubkey(cert); + + /* + * Override the built-in name for the "ECDSA" algorithms OID, with + * the more familiar name. For "RSA" keys report "RSA-PSS", which + * must be used with TLS 1.3. + */ + if ((nid = EVP_PKEY_type(EVP_PKEY_id(pkey))) != NID_undef) { + switch (nid) { + default: + peer_sig_name = OBJ_nid2sn(nid); + break; + + case EVP_PKEY_RSA: + /* For RSA, TLS 1.3 mandates PSS signatures */ + peer_sig_name = "RSA-PSS"; + SIG_PROP(TLScontext, !srvr, bits) = EVP_PKEY_bits(pkey); + break; + +#ifndef OPENSSL_NO_EC + case EVP_PKEY_EC: + peer_sig_name = "ECDSA"; + eckey = EVP_PKEY_get0_EC_KEY(pkey); + nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(eckey)); + peer_sig_curve = EC_curve_nid2nist(nid); + if (!peer_sig_curve) + peer_sig_curve = OBJ_nid2sn(nid); + break; +#endif + } + } + + /* + * With Ed25519 and Ed448 there is no pre-signature digest, but the + * accessor does not fail, rather we get NID_undef. + */ + if (SSL_get_peer_signature_nid(ssl, &nid) && nid != NID_undef) + peer_sig_dgst = OBJ_nid2sn(nid); + + X509_free(cert); + } + if (kex_name) { + TLScontext->kex_name = mystrdup(kex_name); + if (kex_curve) + TLScontext->kex_curve = mystrdup(kex_curve); + } + if (locl_sig_name) { + SIG_PROP(TLScontext, srvr, name) = mystrdup(locl_sig_name); + if (locl_sig_curve) + SIG_PROP(TLScontext, srvr, curve) = mystrdup(locl_sig_curve); + if (locl_sig_dgst) + SIG_PROP(TLScontext, srvr, dgst) = mystrdup(locl_sig_dgst); + } + if (peer_sig_name) { + SIG_PROP(TLScontext, !srvr, name) = mystrdup(peer_sig_name); + if (peer_sig_curve) + SIG_PROP(TLScontext, !srvr, curve) = mystrdup(peer_sig_curve); + if (peer_sig_dgst) + SIG_PROP(TLScontext, !srvr, dgst) = mystrdup(peer_sig_dgst); + } +#endif /* OPENSSL_VERSION_NUMBER ... */ +} + +/* tls_log_summary - TLS loglevel 1 one-liner, embellished with TLS 1.3 details */ + +void tls_log_summary(TLS_ROLE role, TLS_USAGE usage, TLS_SESS_STATE *ctx) +{ + VSTRING *msg = vstring_alloc(100); + const char *direction = (role == TLS_ROLE_CLIENT) ? "to" : "from"; + const char *sni = (role == TLS_ROLE_CLIENT) ? 0 : ctx->peer_sni; + + /* + * When SNI was sent and accepted, the server-side log message now + * includes a "to <sni-name>" detail after the "from <namaddr>" detail + * identifying the remote client. We don't presently log (purportedly) + * accepted SNI on the client side. + */ + vstring_sprintf(msg, "%s TLS connection %s %s %s%s%s: %s" + " with cipher %s (%d/%d bits)", + !TLS_CERT_IS_PRESENT(ctx) ? "Anonymous" : + TLS_CERT_IS_SECURED(ctx) ? "Verified" : + TLS_CERT_IS_TRUSTED(ctx) ? "Trusted" : "Untrusted", + usage == TLS_USAGE_NEW ? "established" : "reused", + direction, ctx->namaddr, sni ? " to " : "", sni ? sni : "", + ctx->protocol, ctx->cipher_name, ctx->cipher_usebits, + ctx->cipher_algbits); + + if (ctx->kex_name && *ctx->kex_name) { + vstring_sprintf_append(msg, " key-exchange %s", ctx->kex_name); + if (ctx->kex_curve && *ctx->kex_curve) + vstring_sprintf_append(msg, " (%s)", ctx->kex_curve); + else if (ctx->kex_bits > 0) + vstring_sprintf_append(msg, " (%d bits)", ctx->kex_bits); + } + if (ctx->srvr_sig_name && *ctx->srvr_sig_name) { + vstring_sprintf_append(msg, " server-signature %s", + ctx->srvr_sig_name); + if (ctx->srvr_sig_curve && *ctx->srvr_sig_curve) + vstring_sprintf_append(msg, " (%s)", ctx->srvr_sig_curve); + else if (ctx->srvr_sig_bits > 0) + vstring_sprintf_append(msg, " (%d bits)", ctx->srvr_sig_bits); + if (ctx->srvr_sig_dgst && *ctx->srvr_sig_dgst) + vstring_sprintf_append(msg, " server-digest %s", + ctx->srvr_sig_dgst); + } + if (ctx->clnt_sig_name && *ctx->clnt_sig_name) { + vstring_sprintf_append(msg, " client-signature %s", + ctx->clnt_sig_name); + if (ctx->clnt_sig_curve && *ctx->clnt_sig_curve) + vstring_sprintf_append(msg, " (%s)", ctx->clnt_sig_curve); + else if (ctx->clnt_sig_bits > 0) + vstring_sprintf_append(msg, " (%d bits)", ctx->clnt_sig_bits); + if (ctx->clnt_sig_dgst && *ctx->clnt_sig_dgst) + vstring_sprintf_append(msg, " client-digest %s", + ctx->clnt_sig_dgst); + } + msg_info("%s", vstring_str(msg)); + vstring_free(msg); +} + +/* tls_alloc_app_context - allocate TLS application context */ + +TLS_APPL_STATE *tls_alloc_app_context(SSL_CTX *ssl_ctx, SSL_CTX *sni_ctx, + int log_mask) +{ + TLS_APPL_STATE *app_ctx; + + app_ctx = (TLS_APPL_STATE *) mymalloc(sizeof(*app_ctx)); + + /* See portability note below with other memset() call. */ + memset((void *) app_ctx, 0, sizeof(*app_ctx)); + app_ctx->ssl_ctx = ssl_ctx; + app_ctx->sni_ctx = sni_ctx; + app_ctx->log_mask = log_mask; + + /* See also: cache purging code in tls_set_ciphers(). */ + app_ctx->cache_type = 0; + + if (tls_server_sni_maps) { + SSL_CTX_set_tlsext_servername_callback(ssl_ctx, server_sni_callback); + SSL_CTX_set_tlsext_servername_arg(ssl_ctx, (void *) sni_ctx); + } + return (app_ctx); +} + +/* tls_free_app_context - Free TLS application context */ + +void tls_free_app_context(TLS_APPL_STATE *app_ctx) +{ + if (app_ctx->ssl_ctx) + SSL_CTX_free(app_ctx->ssl_ctx); + if (app_ctx->sni_ctx) + SSL_CTX_free(app_ctx->sni_ctx); + if (app_ctx->cache_type) + myfree(app_ctx->cache_type); + myfree((void *) app_ctx); +} + +/* tls_alloc_sess_context - allocate TLS session context */ + +TLS_SESS_STATE *tls_alloc_sess_context(int log_mask, const char *namaddr) +{ + TLS_SESS_STATE *TLScontext; + + /* + * PORTABILITY: Do not assume that null pointers are all-zero bits. Use + * explicit assignments to initialize pointers. + * + * See the C language FAQ item 5.17, or if you have time to burn, + * http://www.google.com/search?q=zero+bit+null+pointer + * + * However, it's OK to use memset() to zero integer values. + */ + TLScontext = (TLS_SESS_STATE *) mymalloc(sizeof(TLS_SESS_STATE)); + memset((void *) TLScontext, 0, sizeof(*TLScontext)); + TLScontext->con = 0; + TLScontext->cache_type = 0; + TLScontext->serverid = 0; + TLScontext->peer_CN = 0; + TLScontext->issuer_CN = 0; + TLScontext->peer_sni = 0; + TLScontext->peer_cert_fprint = 0; + TLScontext->peer_pkey_fprint = 0; + TLScontext->protocol = 0; + TLScontext->cipher_name = 0; + TLScontext->kex_name = 0; + TLScontext->kex_curve = 0; + TLScontext->clnt_sig_name = 0; + TLScontext->clnt_sig_curve = 0; + TLScontext->clnt_sig_dgst = 0; + TLScontext->srvr_sig_name = 0; + TLScontext->srvr_sig_curve = 0; + TLScontext->srvr_sig_dgst = 0; + TLScontext->log_mask = log_mask; + TLScontext->namaddr = lowercase(mystrdup(namaddr)); + TLScontext->mdalg = 0; /* Alias for props->mdalg */ + TLScontext->dane = 0; /* Alias for props->dane */ + TLScontext->errordepth = -1; + TLScontext->tadepth = -1; + TLScontext->errorcode = X509_V_OK; + TLScontext->errorcert = 0; + TLScontext->untrusted = 0; + TLScontext->trusted = 0; + + return (TLScontext); +} + +/* tls_free_context - deallocate TLScontext and members */ + +void tls_free_context(TLS_SESS_STATE *TLScontext) +{ + + /* + * Free the SSL structure and the BIOs. Warning: the internal_bio is + * connected to the SSL structure and is automatically freed with it. Do + * not free it again (core dump)!! Only free the network_bio. + */ + if (TLScontext->con != 0) + SSL_free(TLScontext->con); + + if (TLScontext->namaddr) + myfree(TLScontext->namaddr); + if (TLScontext->serverid) + myfree(TLScontext->serverid); + + if (TLScontext->peer_CN) + myfree(TLScontext->peer_CN); + if (TLScontext->issuer_CN) + myfree(TLScontext->issuer_CN); + if (TLScontext->peer_sni) + myfree(TLScontext->peer_sni); + if (TLScontext->peer_cert_fprint) + myfree(TLScontext->peer_cert_fprint); + if (TLScontext->peer_pkey_fprint) + myfree(TLScontext->peer_pkey_fprint); + if (TLScontext->kex_name) + myfree((void *) TLScontext->kex_name); + if (TLScontext->kex_curve) + myfree((void *) TLScontext->kex_curve); + if (TLScontext->clnt_sig_name) + myfree((void *) TLScontext->clnt_sig_name); + if (TLScontext->clnt_sig_curve) + myfree((void *) TLScontext->clnt_sig_curve); + if (TLScontext->clnt_sig_dgst) + myfree((void *) TLScontext->clnt_sig_dgst); + if (TLScontext->srvr_sig_name) + myfree((void *) TLScontext->srvr_sig_name); + if (TLScontext->srvr_sig_curve) + myfree((void *) TLScontext->srvr_sig_curve); + if (TLScontext->srvr_sig_dgst) + myfree((void *) TLScontext->srvr_sig_dgst); + if (TLScontext->errorcert) + X509_free(TLScontext->errorcert); + if (TLScontext->untrusted) + sk_X509_pop_free(TLScontext->untrusted, X509_free); + if (TLScontext->trusted) + sk_X509_pop_free(TLScontext->trusted, X509_free); + + myfree((void *) TLScontext); +} + +/* tls_version_split - Split OpenSSL version number into major, minor, ... */ + +static void tls_version_split(unsigned long version, TLS_VINFO *info) +{ + + /* + * OPENSSL_VERSION_NUMBER(3): + * + * OPENSSL_VERSION_NUMBER is a numeric release version identifier: + * + * MMNNFFPPS: major minor fix patch status + * + * The status nibble has one of the values 0 for development, 1 to e for + * betas 1 to 14, and f for release. Parsed OpenSSL version number. for + * example + * + * 0x000906000 == 0.9.6 dev 0x000906023 == 0.9.6b beta 3 0x00090605f == + * 0.9.6e release + * + * Versions prior to 0.9.3 have identifiers < 0x0930. Versions between + * 0.9.3 and 0.9.5 had a version identifier with this interpretation: + * + * MMNNFFRBB major minor fix final beta/patch + * + * for example + * + * 0x000904100 == 0.9.4 release 0x000905000 == 0.9.5 dev + * + * Version 0.9.5a had an interim interpretation that is like the current + * one, except the patch level got the highest bit set, to keep continu- + * ity. The number was therefore 0x0090581f. + */ + + if (version < 0x0930) { + info->status = 0; + info->patch = version & 0x0f; + version >>= 4; + info->micro = version & 0x0f; + version >>= 4; + info->minor = version & 0x0f; + version >>= 4; + info->major = version & 0x0f; + } else if (version < 0x00905800L) { + info->patch = version & 0xff; + version >>= 8; + info->status = version & 0xf; + version >>= 4; + info->micro = version & 0xff; + version >>= 8; + info->minor = version & 0xff; + version >>= 8; + info->major = version & 0xff; + } else { + info->status = version & 0xf; + version >>= 4; + info->patch = version & 0xff; + version >>= 8; + info->micro = version & 0xff; + version >>= 8; + info->minor = version & 0xff; + version >>= 8; + info->major = version & 0xff; + if (version < 0x00906000L) + info->patch &= ~0x80; + } +} + +/* tls_check_version - Detect mismatch between headers and library. */ + +void tls_check_version(void) +{ + TLS_VINFO hdr_info; + TLS_VINFO lib_info; + + tls_version_split(OPENSSL_VERSION_NUMBER, &hdr_info); + tls_version_split(OpenSSL_version_num(), &lib_info); + + /* + * Warn if run-time library is different from compile-time library, + * allowing later run-time "micro" versions starting with 1.1.0. + */ + if (lib_info.major != hdr_info.major + || lib_info.minor != hdr_info.minor + || (lib_info.micro != hdr_info.micro + && (lib_info.micro < hdr_info.micro + || hdr_info.major == 0 + || (hdr_info.major == 1 && hdr_info.minor == 0)))) + msg_warn("run-time library vs. compile-time header version mismatch: " + "OpenSSL %d.%d.%d may not be compatible with OpenSSL %d.%d.%d", + lib_info.major, lib_info.minor, lib_info.micro, + hdr_info.major, hdr_info.minor, hdr_info.micro); +} + +/* tls_compile_version - compile-time OpenSSL version */ + +const char *tls_compile_version(void) +{ + return (OPENSSL_VERSION_TEXT); +} + +/* tls_run_version - run-time version "major.minor.micro" */ + +const char *tls_run_version(void) +{ + return (OpenSSL_version(OPENSSL_VERSION)); +} + +const char **tls_pkey_algorithms(void) +{ + + /* + * Return an array, not string, so that the result can be inspected + * without parsing. Sort the result alphabetically, not chronologically. + */ + static const char *algs[] = { +#ifndef OPENSSL_NO_DSA + "dsa", +#endif +#ifndef OPENSSL_NO_ECDSA + "ecdsa", +#endif +#ifndef OPENSSL_NO_RSA + "rsa", +#endif + 0, + }; + + return (algs); +} + +/* tls_bug_bits - SSL bug compatibility bits for this OpenSSL version */ + +long tls_bug_bits(void) +{ + long bits = SSL_OP_ALL; /* Work around all known bugs */ + + /* + * Silently ignore any strings that don't appear in the tweaks table, or + * hex bits that are not in SSL_OP_ALL. + */ + if (*var_tls_bug_tweaks) { + bits &= ~long_name_mask_opt(VAR_TLS_BUG_TWEAKS, ssl_bug_tweaks, + var_tls_bug_tweaks, NAME_MASK_ANY_CASE | + NAME_MASK_NUMBER | NAME_MASK_WARN); +#ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG + /* Not relevant to SMTP */ + bits &= ~SSL_OP_SAFARI_ECDHE_ECDSA_BUG; +#endif + } + + /* + * Allow users to set options not in SSL_OP_ALL, and not already managed + * via other Postfix parameters. + */ + if (*var_tls_ssl_options) { + long enable; + + enable = long_name_mask_opt(VAR_TLS_SSL_OPTIONS, ssl_op_tweaks, + var_tls_ssl_options, NAME_MASK_ANY_CASE | + NAME_MASK_NUMBER | NAME_MASK_WARN); + enable &= ~(SSL_OP_ALL | TLS_SSL_OP_MANAGED_BITS); + bits |= enable; + } + + /* + * We unconditionally avoid re-use of ephemeral keys, note that we set DH + * keys via a callback, so reuse was never possible, but the ECDH key is + * set statically, so that is potentially subject to reuse. Set both + * options just in case. + */ + bits |= SSL_OP_SINGLE_ECDH_USE | SSL_OP_SINGLE_DH_USE; + return (bits); +} + +/* tls_print_errors - print and clear the error stack */ + +void tls_print_errors(void) +{ + unsigned long err; + char buffer[1024]; /* XXX */ + const char *file; + const char *data; + int line; + int flags; + + while ((err = ERR_get_error_line_data(&file, &line, &data, &flags)) != 0) { + ERR_error_string_n(err, buffer, sizeof(buffer)); + if (flags & ERR_TXT_STRING) + msg_warn("TLS library problem: %s:%s:%d:%s:", + buffer, file, line, data); + else + msg_warn("TLS library problem: %s:%s:%d:", buffer, file, line); + } +} + +/* tls_info_callback - callback for logging SSL events via Postfix */ + +void tls_info_callback(const SSL *s, int where, int ret) +{ + char *str; + int w; + + /* Adapted from OpenSSL apps/s_cb.c. */ + + w = where & ~SSL_ST_MASK; + + if (w & SSL_ST_CONNECT) + str = "SSL_connect"; + else if (w & SSL_ST_ACCEPT) + str = "SSL_accept"; + else + str = "unknown"; + + if (where & SSL_CB_LOOP) { + msg_info("%s:%s", str, SSL_state_string_long((SSL *) s)); + } else if (where & SSL_CB_ALERT) { + str = (where & SSL_CB_READ) ? "read" : "write"; + if ((ret & 0xff) != SSL3_AD_CLOSE_NOTIFY) + msg_info("SSL3 alert %s:%s:%s", str, + SSL_alert_type_string_long(ret), + SSL_alert_desc_string_long(ret)); + } else if (where & SSL_CB_EXIT) { + if (ret == 0) + msg_info("%s:failed in %s", + str, SSL_state_string_long((SSL *) s)); + else if (ret < 0) { +#ifndef LOG_NON_ERROR_STATES + switch (SSL_get_error((SSL *) s, ret)) { + case SSL_ERROR_WANT_READ: + case SSL_ERROR_WANT_WRITE: + /* Don't log non-error states. */ + break; + default: +#endif + msg_info("%s:error in %s", + str, SSL_state_string_long((SSL *) s)); +#ifndef LOG_NON_ERROR_STATES + } +#endif + } + } +} + + /* + * taken from OpenSSL crypto/bio/b_dump.c. + * + * Modified to save a lot of strcpy and strcat by Matti Aarnio. + * + * Rewritten by Wietse to elimate fixed-size stack buffer, array index + * multiplication and division, sprintf() and strcpy(), and lots of strlen() + * calls. We could make it a little faster by using a fixed-size stack-based + * buffer. + * + * 200412 - use %lx to print pointers, after casting them to unsigned long. + */ + +#define TRUNCATE_SPACE_NULL +#define DUMP_WIDTH 16 +#define VERT_SPLIT 7 + +static void tls_dump_buffer(const unsigned char *start, int len) +{ + VSTRING *buf = vstring_alloc(100); + const unsigned char *last = start + len - 1; + const unsigned char *row; + const unsigned char *col; + int ch; + +#ifdef TRUNCATE_SPACE_NULL + while (last >= start && (*last == ' ' || *last == 0)) + last--; +#endif + + for (row = start; row <= last; row += DUMP_WIDTH) { + VSTRING_RESET(buf); + vstring_sprintf(buf, "%04lx ", (unsigned long) (row - start)); + for (col = row; col < row + DUMP_WIDTH; col++) { + if (col > last) { + vstring_strcat(buf, " "); + } else { + ch = *col; + vstring_sprintf_append(buf, "%02x%c", + ch, col - row == VERT_SPLIT ? '|' : ' '); + } + } + VSTRING_ADDCH(buf, ' '); + for (col = row; col < row + DUMP_WIDTH; col++) { + if (col > last) + break; + ch = *col; + if (!ISPRINT(ch)) + ch = '.'; + VSTRING_ADDCH(buf, ch); + if (col - row == VERT_SPLIT) + VSTRING_ADDCH(buf, ' '); + } + VSTRING_TERMINATE(buf); + msg_info("%s", vstring_str(buf)); + } +#ifdef TRUNCATE_SPACE_NULL + if ((last + 1) - start < len) + msg_info("%04lx - <SPACES/NULLS>", + (unsigned long) ((last + 1) - start)); +#endif + vstring_free(buf); +} + +/* taken from OpenSSL apps/s_cb.c */ + +long tls_bio_dump_cb(BIO *bio, int cmd, const char *argp, int argi, + long unused_argl, long ret) +{ + if (cmd == (BIO_CB_READ | BIO_CB_RETURN)) { + msg_info("read from %08lX [%08lX] (%d bytes => %ld (0x%lX))", + (unsigned long) bio, (unsigned long) argp, argi, + ret, (unsigned long) ret); + tls_dump_buffer((unsigned char *) argp, (int) ret); + } else if (cmd == (BIO_CB_WRITE | BIO_CB_RETURN)) { + msg_info("write to %08lX [%08lX] (%d bytes => %ld (0x%lX))", + (unsigned long) bio, (unsigned long) argp, argi, + ret, (unsigned long) ret); + tls_dump_buffer((unsigned char *) argp, (int) ret); + } + return (ret); +} + +int tls_validate_digest(const char *dgst) +{ + const EVP_MD *md_alg; + unsigned int md_len; + + /* + * Register SHA-2 digests, if implemented and not already registered. + * Improves interoperability with clients and servers that prematurely + * deploy SHA-2 certificates. Also facilitates DANE and TA support. + */ +#if defined(LN_sha256) && defined(NID_sha256) && !defined(OPENSSL_NO_SHA256) + if (!EVP_get_digestbyname(LN_sha224)) + EVP_add_digest(EVP_sha224()); + if (!EVP_get_digestbyname(LN_sha256)) + EVP_add_digest(EVP_sha256()); +#endif +#if defined(LN_sha512) && defined(NID_sha512) && !defined(OPENSSL_NO_SHA512) + if (!EVP_get_digestbyname(LN_sha384)) + EVP_add_digest(EVP_sha384()); + if (!EVP_get_digestbyname(LN_sha512)) + EVP_add_digest(EVP_sha512()); +#endif + + /* + * If the administrator specifies an unsupported digest algorithm, fail + * now, rather than in the middle of a TLS handshake. + */ + if ((md_alg = EVP_get_digestbyname(dgst)) == 0) { + msg_warn("Digest algorithm \"%s\" not found", dgst); + return (0); + } + + /* + * Sanity check: Newer shared libraries may use larger digests. + */ + if ((md_len = EVP_MD_size(md_alg)) > EVP_MAX_MD_SIZE) { + msg_warn("Digest algorithm \"%s\" output size %u too large", + dgst, md_len); + return (0); + } + return (1); +} + +#else + + /* + * Broken linker workaround. + */ +int tls_dummy_for_broken_linkers; + +#endif |