diff options
Diffstat (limited to 'src/interfaces/libpq/fe-secure-openssl.c')
| -rw-r--r-- | src/interfaces/libpq/fe-secure-openssl.c | 2028 |
1 files changed, 2028 insertions, 0 deletions
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c new file mode 100644 index 0000000..af59ff4 --- /dev/null +++ b/src/interfaces/libpq/fe-secure-openssl.c @@ -0,0 +1,2028 @@ +/*------------------------------------------------------------------------- + * + * fe-secure-openssl.c + * OpenSSL support + * + * + * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/interfaces/libpq/fe-secure-openssl.c + * + * NOTES + * + * We don't provide informational callbacks here (like + * info_cb() in be-secure-openssl.c), since there's no good mechanism to + * display such information to the user. + * + *------------------------------------------------------------------------- + */ + +#include "postgres_fe.h" + +#include <signal.h> +#include <fcntl.h> +#include <ctype.h> + +#include "libpq-fe.h" +#include "fe-auth.h" +#include "fe-secure-common.h" +#include "libpq-int.h" + +#ifdef WIN32 +#include "win32.h" +#else +#include <sys/socket.h> +#include <unistd.h> +#include <netdb.h> +#include <netinet/in.h> +#ifdef HAVE_NETINET_TCP_H +#include <netinet/tcp.h> +#endif +#include <arpa/inet.h> +#endif + +#include <sys/stat.h> + +#ifdef ENABLE_THREAD_SAFETY +#ifdef WIN32 +#include "pthread-win32.h" +#else +#include <pthread.h> +#endif +#endif + +/* + * These SSL-related #includes must come after all system-provided headers. + * This ensures that OpenSSL can take care of conflicts with Windows' + * <wincrypt.h> by #undef'ing the conflicting macros. (We don't directly + * include <wincrypt.h>, but some other Windows headers do.) + */ +#include "common/openssl.h" +#include <openssl/conf.h> +#ifdef USE_SSL_ENGINE +#include <openssl/engine.h> +#endif +#include <openssl/x509v3.h> + + +static int verify_cb(int ok, X509_STORE_CTX *ctx); +static int openssl_verify_peer_name_matches_certificate_name(PGconn *conn, + ASN1_STRING *name, + char **store_name); +static int openssl_verify_peer_name_matches_certificate_ip(PGconn *conn, + ASN1_OCTET_STRING *addr_entry, + char **store_name); +static void destroy_ssl_system(void); +static int initialize_SSL(PGconn *conn); +static PostgresPollingStatusType open_client_SSL(PGconn *); +static char *SSLerrmessage(unsigned long ecode); +static void SSLerrfree(char *buf); +static int PQssl_passwd_cb(char *buf, int size, int rwflag, void *userdata); + +static int my_sock_read(BIO *h, char *buf, int size); +static int my_sock_write(BIO *h, const char *buf, int size); +static BIO_METHOD *my_BIO_s_socket(void); +static int my_SSL_set_fd(PGconn *conn, int fd); + + +static bool pq_init_ssl_lib = true; +static bool pq_init_crypto_lib = true; + +static bool ssl_lib_initialized = false; + +#ifdef ENABLE_THREAD_SAFETY +static long crypto_open_connections = 0; + +#ifndef WIN32 +static pthread_mutex_t ssl_config_mutex = PTHREAD_MUTEX_INITIALIZER; +#else +static pthread_mutex_t ssl_config_mutex = NULL; +static long win32_ssl_create_mutex = 0; +#endif +#endif /* ENABLE_THREAD_SAFETY */ + +static PQsslKeyPassHook_OpenSSL_type PQsslKeyPassHook = NULL; +static int ssl_protocol_version_to_openssl(const char *protocol); + +/* ------------------------------------------------------------ */ +/* Procedures common to all secure sessions */ +/* ------------------------------------------------------------ */ + +void +pgtls_init_library(bool do_ssl, int do_crypto) +{ +#ifdef ENABLE_THREAD_SAFETY + + /* + * Disallow changing the flags while we have open connections, else we'd + * get completely confused. + */ + if (crypto_open_connections != 0) + return; +#endif + + pq_init_ssl_lib = do_ssl; + pq_init_crypto_lib = do_crypto; +} + +PostgresPollingStatusType +pgtls_open_client(PGconn *conn) +{ + /* First time through? */ + if (conn->ssl == NULL) + { + /* + * Create a connection-specific SSL object, and load client + * certificate, private key, and trusted CA certs. + */ + if (initialize_SSL(conn) != 0) + { + /* initialize_SSL already put a message in conn->errorMessage */ + pgtls_close(conn); + return PGRES_POLLING_FAILED; + } + } + + /* Begin or continue the actual handshake */ + return open_client_SSL(conn); +} + +ssize_t +pgtls_read(PGconn *conn, void *ptr, size_t len) +{ + ssize_t n; + int result_errno = 0; + char sebuf[PG_STRERROR_R_BUFLEN]; + int err; + unsigned long ecode; + +rloop: + + /* + * Prepare to call SSL_get_error() by clearing thread's OpenSSL error + * queue. In general, the current thread's error queue must be empty + * before the TLS/SSL I/O operation is attempted, or SSL_get_error() will + * not work reliably. Since the possibility exists that other OpenSSL + * clients running in the same thread but not under our control will fail + * to call ERR_get_error() themselves (after their own I/O operations), + * pro-actively clear the per-thread error queue now. + */ + SOCK_ERRNO_SET(0); + ERR_clear_error(); + n = SSL_read(conn->ssl, ptr, len); + err = SSL_get_error(conn->ssl, n); + + /* + * Other clients of OpenSSL may fail to call ERR_get_error(), but we + * always do, so as to not cause problems for OpenSSL clients that don't + * call ERR_clear_error() defensively. Be sure that this happens by + * calling now. SSL_get_error() relies on the OpenSSL per-thread error + * queue being intact, so this is the earliest possible point + * ERR_get_error() may be called. + */ + ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0; + switch (err) + { + case SSL_ERROR_NONE: + if (n < 0) + { + /* Not supposed to happen, so we don't translate the msg */ + appendPQExpBufferStr(&conn->errorMessage, + "SSL_read failed but did not provide error information\n"); + /* assume the connection is broken */ + result_errno = ECONNRESET; + } + break; + case SSL_ERROR_WANT_READ: + n = 0; + break; + case SSL_ERROR_WANT_WRITE: + + /* + * Returning 0 here would cause caller to wait for read-ready, + * which is not correct since what SSL wants is wait for + * write-ready. The former could get us stuck in an infinite + * wait, so don't risk it; busy-loop instead. + */ + goto rloop; + case SSL_ERROR_SYSCALL: + if (n < 0) + { + result_errno = SOCK_ERRNO; + if (result_errno == EPIPE || + result_errno == ECONNRESET) + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("server closed the connection unexpectedly\n" + "\tThis probably means the server terminated abnormally\n" + "\tbefore or while processing the request.\n")); + else + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSL SYSCALL error: %s\n"), + SOCK_STRERROR(result_errno, + sebuf, sizeof(sebuf))); + } + else + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL SYSCALL error: EOF detected\n")); + /* assume the connection is broken */ + result_errno = ECONNRESET; + n = -1; + } + break; + case SSL_ERROR_SSL: + { + char *errm = SSLerrmessage(ecode); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSL error: %s\n"), errm); + SSLerrfree(errm); + /* assume the connection is broken */ + result_errno = ECONNRESET; + n = -1; + break; + } + case SSL_ERROR_ZERO_RETURN: + + /* + * Per OpenSSL documentation, this error code is only returned for + * a clean connection closure, so we should not report it as a + * server crash. + */ + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL connection has been closed unexpectedly\n")); + result_errno = ECONNRESET; + n = -1; + break; + default: + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("unrecognized SSL error code: %d\n"), + err); + /* assume the connection is broken */ + result_errno = ECONNRESET; + n = -1; + break; + } + + /* ensure we return the intended errno to caller */ + SOCK_ERRNO_SET(result_errno); + + return n; +} + +bool +pgtls_read_pending(PGconn *conn) +{ + return SSL_pending(conn->ssl) > 0; +} + +ssize_t +pgtls_write(PGconn *conn, const void *ptr, size_t len) +{ + ssize_t n; + int result_errno = 0; + char sebuf[PG_STRERROR_R_BUFLEN]; + int err; + unsigned long ecode; + + SOCK_ERRNO_SET(0); + ERR_clear_error(); + n = SSL_write(conn->ssl, ptr, len); + err = SSL_get_error(conn->ssl, n); + ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0; + switch (err) + { + case SSL_ERROR_NONE: + if (n < 0) + { + /* Not supposed to happen, so we don't translate the msg */ + appendPQExpBufferStr(&conn->errorMessage, + "SSL_write failed but did not provide error information\n"); + /* assume the connection is broken */ + result_errno = ECONNRESET; + } + break; + case SSL_ERROR_WANT_READ: + + /* + * Returning 0 here causes caller to wait for write-ready, which + * is not really the right thing, but it's the best we can do. + */ + n = 0; + break; + case SSL_ERROR_WANT_WRITE: + n = 0; + break; + case SSL_ERROR_SYSCALL: + if (n < 0) + { + result_errno = SOCK_ERRNO; + if (result_errno == EPIPE || result_errno == ECONNRESET) + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("server closed the connection unexpectedly\n" + "\tThis probably means the server terminated abnormally\n" + "\tbefore or while processing the request.\n")); + else + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSL SYSCALL error: %s\n"), + SOCK_STRERROR(result_errno, + sebuf, sizeof(sebuf))); + } + else + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL SYSCALL error: EOF detected\n")); + /* assume the connection is broken */ + result_errno = ECONNRESET; + n = -1; + } + break; + case SSL_ERROR_SSL: + { + char *errm = SSLerrmessage(ecode); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSL error: %s\n"), errm); + SSLerrfree(errm); + /* assume the connection is broken */ + result_errno = ECONNRESET; + n = -1; + break; + } + case SSL_ERROR_ZERO_RETURN: + + /* + * Per OpenSSL documentation, this error code is only returned for + * a clean connection closure, so we should not report it as a + * server crash. + */ + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL connection has been closed unexpectedly\n")); + result_errno = ECONNRESET; + n = -1; + break; + default: + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("unrecognized SSL error code: %d\n"), + err); + /* assume the connection is broken */ + result_errno = ECONNRESET; + n = -1; + break; + } + + /* ensure we return the intended errno to caller */ + SOCK_ERRNO_SET(result_errno); + + return n; +} + +#if defined(HAVE_X509_GET_SIGNATURE_NID) || defined(HAVE_X509_GET_SIGNATURE_INFO) +char * +pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len) +{ + X509 *peer_cert; + const EVP_MD *algo_type; + unsigned char hash[EVP_MAX_MD_SIZE]; /* size for SHA-512 */ + unsigned int hash_size; + int algo_nid; + char *cert_hash; + + *len = 0; + + if (!conn->peer) + return NULL; + + peer_cert = conn->peer; + + /* + * Get the signature algorithm of the certificate to determine the hash + * algorithm to use for the result. Prefer X509_get_signature_info(), + * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures. + */ +#if HAVE_X509_GET_SIGNATURE_INFO + if (!X509_get_signature_info(peer_cert, &algo_nid, NULL, NULL, NULL)) +#else + if (!OBJ_find_sigid_algs(X509_get_signature_nid(peer_cert), + &algo_nid, NULL)) +#endif + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("could not determine server certificate signature algorithm\n")); + return NULL; + } + + /* + * The TLS server's certificate bytes need to be hashed with SHA-256 if + * its signature algorithm is MD5 or SHA-1 as per RFC 5929 + * (https://tools.ietf.org/html/rfc5929#section-4.1). If something else + * is used, the same hash as the signature algorithm is used. + */ + switch (algo_nid) + { + case NID_md5: + case NID_sha1: + algo_type = EVP_sha256(); + break; + default: + algo_type = EVP_get_digestbynid(algo_nid); + if (algo_type == NULL) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not find digest for NID %s\n"), + OBJ_nid2sn(algo_nid)); + return NULL; + } + break; + } + + if (!X509_digest(peer_cert, algo_type, hash, &hash_size)) + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("could not generate peer certificate hash\n")); + return NULL; + } + + /* save result */ + cert_hash = malloc(hash_size); + if (cert_hash == NULL) + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("out of memory\n")); + return NULL; + } + memcpy(cert_hash, hash, hash_size); + *len = hash_size; + + return cert_hash; +} +#endif /* HAVE_X509_GET_SIGNATURE_NID */ + +/* ------------------------------------------------------------ */ +/* OpenSSL specific code */ +/* ------------------------------------------------------------ */ + +/* + * Certificate verification callback + * + * This callback allows us to log intermediate problems during + * verification, but there doesn't seem to be a clean way to get + * our PGconn * structure. So we can't log anything! + * + * This callback also allows us to override the default acceptance + * criteria (e.g., accepting self-signed or expired certs), but + * for now we accept the default checks. + */ +static int +verify_cb(int ok, X509_STORE_CTX *ctx) +{ + return ok; +} + + +/* + * OpenSSL-specific wrapper around + * pq_verify_peer_name_matches_certificate_name(), converting the ASN1_STRING + * into a plain C string. + */ +static int +openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *name_entry, + char **store_name) +{ + int len; + const unsigned char *namedata; + + /* Should not happen... */ + if (name_entry == NULL) + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL certificate's name entry is missing\n")); + return -1; + } + + /* + * GEN_DNS can be only IA5String, equivalent to US ASCII. + */ +#ifdef HAVE_ASN1_STRING_GET0_DATA + namedata = ASN1_STRING_get0_data(name_entry); +#else + namedata = ASN1_STRING_data(name_entry); +#endif + len = ASN1_STRING_length(name_entry); + + /* OK to cast from unsigned to plain char, since it's all ASCII. */ + return pq_verify_peer_name_matches_certificate_name(conn, (const char *) namedata, len, store_name); +} + +/* + * OpenSSL-specific wrapper around + * pq_verify_peer_name_matches_certificate_ip(), converting the + * ASN1_OCTET_STRING into a plain C string. + */ +static int +openssl_verify_peer_name_matches_certificate_ip(PGconn *conn, + ASN1_OCTET_STRING *addr_entry, + char **store_name) +{ + int len; + const unsigned char *addrdata; + + /* Should not happen... */ + if (addr_entry == NULL) + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL certificate's address entry is missing\n")); + return -1; + } + + /* + * GEN_IPADD is an OCTET STRING containing an IP address in network byte + * order. + */ +#ifdef HAVE_ASN1_STRING_GET0_DATA + addrdata = ASN1_STRING_get0_data(addr_entry); +#else + addrdata = ASN1_STRING_data(addr_entry); +#endif + len = ASN1_STRING_length(addr_entry); + + return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name); +} + +static bool +is_ip_address(const char *host) +{ + struct in_addr dummy4; +#ifdef HAVE_INET_PTON + struct in6_addr dummy6; +#endif + + return inet_aton(host, &dummy4) +#ifdef HAVE_INET_PTON + || (inet_pton(AF_INET6, host, &dummy6) == 1) +#endif + ; +} + +/* + * Verify that the server certificate matches the hostname we connected to. + * + * The certificate's Common Name and Subject Alternative Names are considered. + */ +int +pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn, + int *names_examined, + char **first_name) +{ + STACK_OF(GENERAL_NAME) * peer_san; + int i; + int rc = 0; + char *host = conn->connhost[conn->whichhost].host; + int host_type; + bool check_cn = true; + + Assert(host && host[0]); /* should be guaranteed by caller */ + + /* + * We try to match the NSS behavior here, which is a slight departure from + * the spec but seems to make more intuitive sense: + * + * If connhost contains a DNS name, and the certificate's SANs contain any + * dNSName entries, then we'll ignore the Subject Common Name entirely; + * otherwise, we fall back to checking the CN. (This behavior matches the + * RFC.) + * + * If connhost contains an IP address, and the SANs contain iPAddress + * entries, we again ignore the CN. Otherwise, we allow the CN to match, + * EVEN IF there is a dNSName in the SANs. (RFC 6125 prohibits this: "A + * client MUST NOT seek a match for a reference identifier of CN-ID if the + * presented identifiers include a DNS-ID, SRV-ID, URI-ID, or any + * application-specific identifier types supported by the client.") + * + * NOTE: Prior versions of libpq did not consider iPAddress entries at + * all, so this new behavior might break a certificate that has different + * IP addresses in the Subject CN and the SANs. + */ + if (is_ip_address(host)) + host_type = GEN_IPADD; + else + host_type = GEN_DNS; + + /* + * First, get the Subject Alternative Names (SANs) from the certificate, + * and compare them against the originally given hostname. + */ + peer_san = (STACK_OF(GENERAL_NAME) *) + X509_get_ext_d2i(conn->peer, NID_subject_alt_name, NULL, NULL); + + if (peer_san) + { + int san_len = sk_GENERAL_NAME_num(peer_san); + + for (i = 0; i < san_len; i++) + { + const GENERAL_NAME *name = sk_GENERAL_NAME_value(peer_san, i); + char *alt_name = NULL; + + if (name->type == host_type) + { + /* + * This SAN is of the same type (IP or DNS) as our host name, + * so don't allow a fallback check of the CN. + */ + check_cn = false; + } + + if (name->type == GEN_DNS) + { + (*names_examined)++; + rc = openssl_verify_peer_name_matches_certificate_name(conn, + name->d.dNSName, + &alt_name); + } + else if (name->type == GEN_IPADD) + { + (*names_examined)++; + rc = openssl_verify_peer_name_matches_certificate_ip(conn, + name->d.iPAddress, + &alt_name); + } + + if (alt_name) + { + if (!*first_name) + *first_name = alt_name; + else + free(alt_name); + } + + if (rc != 0) + { + /* + * Either we hit an error or a match, and either way we should + * not fall back to the CN. + */ + check_cn = false; + break; + } + } + sk_GENERAL_NAME_pop_free(peer_san, GENERAL_NAME_free); + } + + /* + * If there is no subjectAltName extension of the matching type, check the + * Common Name. + * + * (Per RFC 2818 and RFC 6125, if the subjectAltName extension of type + * dNSName is present, the CN must be ignored. We break this rule if host + * is an IP address; see the comment above.) + */ + if (check_cn) + { + X509_NAME *subject_name; + + subject_name = X509_get_subject_name(conn->peer); + if (subject_name != NULL) + { + int cn_index; + + cn_index = X509_NAME_get_index_by_NID(subject_name, + NID_commonName, -1); + if (cn_index >= 0) + { + char *common_name = NULL; + + (*names_examined)++; + rc = openssl_verify_peer_name_matches_certificate_name(conn, + X509_NAME_ENTRY_get_data(X509_NAME_get_entry(subject_name, cn_index)), + &common_name); + + if (common_name) + { + if (!*first_name) + *first_name = common_name; + else + free(common_name); + } + } + } + } + + return rc; +} + +#if defined(ENABLE_THREAD_SAFETY) && defined(HAVE_CRYPTO_LOCK) +/* + * Callback functions for OpenSSL internal locking. (OpenSSL 1.1.0 + * does its own locking, and doesn't need these anymore. The + * CRYPTO_lock() function was removed in 1.1.0, when the callbacks + * were made obsolete, so we assume that if CRYPTO_lock() exists, + * the callbacks are still required.) + */ + +static unsigned long +pq_threadidcallback(void) +{ + /* + * This is not standards-compliant. pthread_self() returns pthread_t, and + * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires + * it, so we have to do it. + */ + return (unsigned long) pthread_self(); +} + +static pthread_mutex_t *pq_lockarray; + +static void +pq_lockingcallback(int mode, int n, const char *file, int line) +{ + /* + * There's no way to report a mutex-primitive failure, so we just Assert + * in development builds, and ignore any errors otherwise. Fortunately + * this is all obsolete in modern OpenSSL. + */ + if (mode & CRYPTO_LOCK) + { + if (pthread_mutex_lock(&pq_lockarray[n])) + Assert(false); + } + else + { + if (pthread_mutex_unlock(&pq_lockarray[n])) + Assert(false); + } +} +#endif /* ENABLE_THREAD_SAFETY && HAVE_CRYPTO_LOCK */ + +/* + * Initialize SSL library. + * + * In threadsafe mode, this includes setting up libcrypto callback functions + * to do thread locking. + * + * If the caller has told us (through PQinitOpenSSL) that he's taking care + * of libcrypto, we expect that callbacks are already set, and won't try to + * override it. + */ +int +pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto) +{ +#ifdef ENABLE_THREAD_SAFETY +#ifdef WIN32 + /* Also see similar code in fe-connect.c, default_threadlock() */ + if (ssl_config_mutex == NULL) + { + while (InterlockedExchange(&win32_ssl_create_mutex, 1) == 1) + /* loop, another thread own the lock */ ; + if (ssl_config_mutex == NULL) + { + if (pthread_mutex_init(&ssl_config_mutex, NULL)) + return -1; + } + InterlockedExchange(&win32_ssl_create_mutex, 0); + } +#endif + if (pthread_mutex_lock(&ssl_config_mutex)) + return -1; + +#ifdef HAVE_CRYPTO_LOCK + if (pq_init_crypto_lib) + { + /* + * If necessary, set up an array to hold locks for libcrypto. + * libcrypto will tell us how big to make this array. + */ + if (pq_lockarray == NULL) + { + int i; + + pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks()); + if (!pq_lockarray) + { + pthread_mutex_unlock(&ssl_config_mutex); + return -1; + } + for (i = 0; i < CRYPTO_num_locks(); i++) + { + if (pthread_mutex_init(&pq_lockarray[i], NULL)) + { + free(pq_lockarray); + pq_lockarray = NULL; + pthread_mutex_unlock(&ssl_config_mutex); + return -1; + } + } + } + + if (do_crypto && !conn->crypto_loaded) + { + if (crypto_open_connections++ == 0) + { + /* + * These are only required for threaded libcrypto + * applications, but make sure we don't stomp on them if + * they're already set. + */ + if (CRYPTO_get_id_callback() == NULL) + CRYPTO_set_id_callback(pq_threadidcallback); + if (CRYPTO_get_locking_callback() == NULL) + CRYPTO_set_locking_callback(pq_lockingcallback); + } + + conn->crypto_loaded = true; + } + } +#endif /* HAVE_CRYPTO_LOCK */ +#endif /* ENABLE_THREAD_SAFETY */ + + if (!ssl_lib_initialized && do_ssl) + { + if (pq_init_ssl_lib) + { +#ifdef HAVE_OPENSSL_INIT_SSL + OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL); +#else + OPENSSL_config(NULL); + SSL_library_init(); + SSL_load_error_strings(); +#endif + } + ssl_lib_initialized = true; + } + +#ifdef ENABLE_THREAD_SAFETY + pthread_mutex_unlock(&ssl_config_mutex); +#endif + return 0; +} + +/* + * This function is needed because if the libpq library is unloaded + * from the application, the callback functions will no longer exist when + * libcrypto is used by other parts of the system. For this reason, + * we unregister the callback functions when the last libpq + * connection is closed. (The same would apply for OpenSSL callbacks + * if we had any.) + * + * Callbacks are only set when we're compiled in threadsafe mode, so + * we only need to remove them in this case. They are also not needed + * with OpenSSL 1.1.0 anymore. + */ +static void +destroy_ssl_system(void) +{ +#if defined(ENABLE_THREAD_SAFETY) && defined(HAVE_CRYPTO_LOCK) + /* Mutex is created in pgtls_init() */ + if (pthread_mutex_lock(&ssl_config_mutex)) + return; + + if (pq_init_crypto_lib && crypto_open_connections > 0) + --crypto_open_connections; + + if (pq_init_crypto_lib && crypto_open_connections == 0) + { + /* + * No connections left, unregister libcrypto callbacks, if no one + * registered different ones in the meantime. + */ + if (CRYPTO_get_locking_callback() == pq_lockingcallback) + CRYPTO_set_locking_callback(NULL); + if (CRYPTO_get_id_callback() == pq_threadidcallback) + CRYPTO_set_id_callback(NULL); + + /* + * We don't free the lock array. If we get another connection in this + * process, we will just re-use them with the existing mutexes. + * + * This means we leak a little memory on repeated load/unload of the + * library. + */ + } + + pthread_mutex_unlock(&ssl_config_mutex); +#endif +} + +/* + * Create per-connection SSL object, and load the client certificate, + * private key, and trusted CA certs. + * + * Returns 0 if OK, -1 on failure (with a message in conn->errorMessage). + */ +static int +initialize_SSL(PGconn *conn) +{ + SSL_CTX *SSL_context; + struct stat buf; + char homedir[MAXPGPATH]; + char fnbuf[MAXPGPATH]; + char sebuf[PG_STRERROR_R_BUFLEN]; + bool have_homedir; + bool have_cert; + bool have_rootcert; + EVP_PKEY *pkey = NULL; + + /* + * We'll need the home directory if any of the relevant parameters are + * defaulted. If pqGetHomeDirectory fails, act as though none of the + * files could be found. + */ + if (!(conn->sslcert && strlen(conn->sslcert) > 0) || + !(conn->sslkey && strlen(conn->sslkey) > 0) || + !(conn->sslrootcert && strlen(conn->sslrootcert) > 0) || + !((conn->sslcrl && strlen(conn->sslcrl) > 0) || + (conn->sslcrldir && strlen(conn->sslcrldir) > 0))) + have_homedir = pqGetHomeDirectory(homedir, sizeof(homedir)); + else /* won't need it */ + have_homedir = false; + + /* + * Create a new SSL_CTX object. + * + * We used to share a single SSL_CTX between all connections, but it was + * complicated if connections used different certificates. So now we + * create a separate context for each connection, and accept the overhead. + */ + SSL_context = SSL_CTX_new(SSLv23_method()); + if (!SSL_context) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not create SSL context: %s\n"), + err); + SSLerrfree(err); + return -1; + } + + /* + * Delegate the client cert password prompt to the libpq wrapper callback + * if any is defined. + * + * If the application hasn't installed its own and the sslpassword + * parameter is non-null, we install ours now to make sure we supply + * PGconn->sslpassword to OpenSSL instead of letting it prompt on stdin. + * + * This will replace OpenSSL's default PEM_def_callback (which prompts on + * stdin), but we're only setting it for this SSL context so it's + * harmless. + */ + if (PQsslKeyPassHook + || (conn->sslpassword && strlen(conn->sslpassword) > 0)) + { + SSL_CTX_set_default_passwd_cb(SSL_context, PQssl_passwd_cb); + SSL_CTX_set_default_passwd_cb_userdata(SSL_context, conn); + } + + /* Disable old protocol versions */ + SSL_CTX_set_options(SSL_context, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3); + + /* Set the minimum and maximum protocol versions if necessary */ + if (conn->ssl_min_protocol_version && + strlen(conn->ssl_min_protocol_version) != 0) + { + int ssl_min_ver; + + ssl_min_ver = ssl_protocol_version_to_openssl(conn->ssl_min_protocol_version); + + if (ssl_min_ver == -1) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("invalid value \"%s\" for minimum SSL protocol version\n"), + conn->ssl_min_protocol_version); + SSL_CTX_free(SSL_context); + return -1; + } + + if (!SSL_CTX_set_min_proto_version(SSL_context, ssl_min_ver)) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not set minimum SSL protocol version: %s\n"), + err); + SSLerrfree(err); + SSL_CTX_free(SSL_context); + return -1; + } + } + + if (conn->ssl_max_protocol_version && + strlen(conn->ssl_max_protocol_version) != 0) + { + int ssl_max_ver; + + ssl_max_ver = ssl_protocol_version_to_openssl(conn->ssl_max_protocol_version); + + if (ssl_max_ver == -1) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("invalid value \"%s\" for maximum SSL protocol version\n"), + conn->ssl_max_protocol_version); + SSL_CTX_free(SSL_context); + return -1; + } + + if (!SSL_CTX_set_max_proto_version(SSL_context, ssl_max_ver)) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not set maximum SSL protocol version: %s\n"), + err); + SSLerrfree(err); + SSL_CTX_free(SSL_context); + return -1; + } + } + + /* + * Disable OpenSSL's moving-write-buffer sanity check, because it causes + * unnecessary failures in nonblocking send cases. + */ + SSL_CTX_set_mode(SSL_context, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER); + + /* + * If the root cert file exists, load it so we can perform certificate + * verification. If sslmode is "verify-full" we will also do further + * verification after the connection has been completed. + */ + if (conn->sslrootcert && strlen(conn->sslrootcert) > 0) + strlcpy(fnbuf, conn->sslrootcert, sizeof(fnbuf)); + else if (have_homedir) + snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, ROOT_CERT_FILE); + else + fnbuf[0] = '\0'; + + if (fnbuf[0] != '\0' && + stat(fnbuf, &buf) == 0) + { + X509_STORE *cvstore; + + if (SSL_CTX_load_verify_locations(SSL_context, fnbuf, NULL) != 1) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not read root certificate file \"%s\": %s\n"), + fnbuf, err); + SSLerrfree(err); + SSL_CTX_free(SSL_context); + return -1; + } + + if ((cvstore = SSL_CTX_get_cert_store(SSL_context)) != NULL) + { + char *fname = NULL; + char *dname = NULL; + + if (conn->sslcrl && strlen(conn->sslcrl) > 0) + fname = conn->sslcrl; + if (conn->sslcrldir && strlen(conn->sslcrldir) > 0) + dname = conn->sslcrldir; + + /* defaults to use the default CRL file */ + if (!fname && !dname && have_homedir) + { + snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, ROOT_CRL_FILE); + fname = fnbuf; + } + + /* Set the flags to check against the complete CRL chain */ + if ((fname || dname) && + X509_STORE_load_locations(cvstore, fname, dname) == 1) + { + X509_STORE_set_flags(cvstore, + X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL); + } + + /* if not found, silently ignore; we do not require CRL */ + ERR_clear_error(); + } + have_rootcert = true; + } + else + { + /* + * stat() failed; assume root file doesn't exist. If sslmode is + * verify-ca or verify-full, this is an error. Otherwise, continue + * without performing any server cert verification. + */ + if (conn->sslmode[0] == 'v') /* "verify-ca" or "verify-full" */ + { + /* + * The only way to reach here with an empty filename is if + * pqGetHomeDirectory failed. That's a sufficiently unusual case + * that it seems worth having a specialized error message for it. + */ + if (fnbuf[0] == '\0') + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not get home directory to locate root certificate file\n" + "Either provide the file or change sslmode to disable server certificate verification.\n")); + else + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("root certificate file \"%s\" does not exist\n" + "Either provide the file or change sslmode to disable server certificate verification.\n"), fnbuf); + SSL_CTX_free(SSL_context); + return -1; + } + have_rootcert = false; + } + + /* Read the client certificate file */ + if (conn->sslcert && strlen(conn->sslcert) > 0) + strlcpy(fnbuf, conn->sslcert, sizeof(fnbuf)); + else if (have_homedir) + snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, USER_CERT_FILE); + else + fnbuf[0] = '\0'; + + if (fnbuf[0] == '\0') + { + /* no home directory, proceed without a client cert */ + have_cert = false; + } + else if (stat(fnbuf, &buf) != 0) + { + /* + * If file is not present, just go on without a client cert; server + * might or might not accept the connection. Any other error, + * however, is grounds for complaint. + */ + if (errno != ENOENT && errno != ENOTDIR) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not open certificate file \"%s\": %s\n"), + fnbuf, strerror_r(errno, sebuf, sizeof(sebuf))); + SSL_CTX_free(SSL_context); + return -1; + } + have_cert = false; + } + else + { + /* + * Cert file exists, so load it. Since OpenSSL doesn't provide the + * equivalent of "SSL_use_certificate_chain_file", we have to load it + * into the SSL context, rather than the SSL object. + */ + if (SSL_CTX_use_certificate_chain_file(SSL_context, fnbuf) != 1) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not read certificate file \"%s\": %s\n"), + fnbuf, err); + SSLerrfree(err); + SSL_CTX_free(SSL_context); + return -1; + } + + /* need to load the associated private key, too */ + have_cert = true; + } + + /* + * The SSL context is now loaded with the correct root and client + * certificates. Create a connection-specific SSL object. The private key + * is loaded directly into the SSL object. (We could load the private key + * into the context, too, but we have done it this way historically, and + * it doesn't really matter.) + */ + if (!(conn->ssl = SSL_new(SSL_context)) || + !SSL_set_app_data(conn->ssl, conn) || + !my_SSL_set_fd(conn, conn->sock)) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not establish SSL connection: %s\n"), + err); + SSLerrfree(err); + SSL_CTX_free(SSL_context); + return -1; + } + conn->ssl_in_use = true; + + /* + * SSL contexts are reference counted by OpenSSL. We can free it as soon + * as we have created the SSL object, and it will stick around for as long + * as it's actually needed. + */ + SSL_CTX_free(SSL_context); + SSL_context = NULL; + + /* + * Set Server Name Indication (SNI), if enabled by connection parameters. + * Per RFC 6066, do not set it if the host is a literal IP address (IPv4 + * or IPv6). + */ + if (conn->sslsni && conn->sslsni[0] == '1') + { + const char *host = conn->connhost[conn->whichhost].host; + + if (host && host[0] && + !(strspn(host, "0123456789.") == strlen(host) || + strchr(host, ':'))) + { + if (SSL_set_tlsext_host_name(conn->ssl, host) != 1) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not set SSL Server Name Indication (SNI): %s\n"), + err); + SSLerrfree(err); + return -1; + } + } + } + + /* + * Read the SSL key. If a key is specified, treat it as an engine:key + * combination if there is colon present - we don't support files with + * colon in the name. The exception is if the second character is a colon, + * in which case it can be a Windows filename with drive specification. + */ + if (have_cert && conn->sslkey && strlen(conn->sslkey) > 0) + { +#ifdef USE_SSL_ENGINE + if (strchr(conn->sslkey, ':') +#ifdef WIN32 + && conn->sslkey[1] != ':' +#endif + ) + { + /* Colon, but not in second character, treat as engine:key */ + char *engine_str = strdup(conn->sslkey); + char *engine_colon; + + if (engine_str == NULL) + { + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("out of memory\n")); + return -1; + } + + /* cannot return NULL because we already checked before strdup */ + engine_colon = strchr(engine_str, ':'); + + *engine_colon = '\0'; /* engine_str now has engine name */ + engine_colon++; /* engine_colon now has key name */ + + conn->engine = ENGINE_by_id(engine_str); + if (conn->engine == NULL) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not load SSL engine \"%s\": %s\n"), + engine_str, err); + SSLerrfree(err); + free(engine_str); + return -1; + } + + if (ENGINE_init(conn->engine) == 0) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not initialize SSL engine \"%s\": %s\n"), + engine_str, err); + SSLerrfree(err); + ENGINE_free(conn->engine); + conn->engine = NULL; + free(engine_str); + return -1; + } + + pkey = ENGINE_load_private_key(conn->engine, engine_colon, + NULL, NULL); + if (pkey == NULL) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not read private SSL key \"%s\" from engine \"%s\": %s\n"), + engine_colon, engine_str, err); + SSLerrfree(err); + ENGINE_finish(conn->engine); + ENGINE_free(conn->engine); + conn->engine = NULL; + free(engine_str); + return -1; + } + if (SSL_use_PrivateKey(conn->ssl, pkey) != 1) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not load private SSL key \"%s\" from engine \"%s\": %s\n"), + engine_colon, engine_str, err); + SSLerrfree(err); + ENGINE_finish(conn->engine); + ENGINE_free(conn->engine); + conn->engine = NULL; + free(engine_str); + return -1; + } + + free(engine_str); + + fnbuf[0] = '\0'; /* indicate we're not going to load from a + * file */ + } + else +#endif /* USE_SSL_ENGINE */ + { + /* PGSSLKEY is not an engine, treat it as a filename */ + strlcpy(fnbuf, conn->sslkey, sizeof(fnbuf)); + } + } + else if (have_homedir) + { + /* No PGSSLKEY specified, load default file */ + snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, USER_KEY_FILE); + } + else + fnbuf[0] = '\0'; + + if (have_cert && fnbuf[0] != '\0') + { + /* read the client key from file */ + + if (stat(fnbuf, &buf) != 0) + { + if (errno == ENOENT) + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("certificate present, but not private key file \"%s\"\n"), + fnbuf); + else + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not stat private key file \"%s\": %m\n"), + fnbuf); + return -1; + } + + /* Key file must be a regular file */ + if (!S_ISREG(buf.st_mode)) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("private key file \"%s\" is not a regular file\n"), + fnbuf); + return -1; + } + + /* + * Refuse to load world-readable key files. We accept root-owned + * files with mode 0640 or less, so that we can access system-wide + * certificates if we have a supplementary group membership that + * allows us to read 'em. For files with non-root ownership, require + * mode 0600 or less. We need not check the file's ownership exactly; + * if we're able to read it despite it having such restrictive + * permissions, it must have the right ownership. + * + * Note: be very careful about tightening these rules. Some people + * expect, for example, that a client process running as root should + * be able to use a non-root-owned key file. + * + * Note that roughly similar checks are performed in + * src/backend/libpq/be-secure-common.c so any changes here may need + * to be made there as well. However, this code caters for the case + * of current user == root, while that code does not. + * + * Ideally we would do similar permissions checks on Windows, but it + * is not clear how that would work since Unix-style permissions may + * not be available. + */ +#if !defined(WIN32) && !defined(__CYGWIN__) + if (buf.st_uid == 0 ? + buf.st_mode & (S_IWGRP | S_IXGRP | S_IRWXO) : + buf.st_mode & (S_IRWXG | S_IRWXO)) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("private key file \"%s\" has group or world access; file must have permissions u=rw (0600) or less if owned by the current user, or permissions u=rw,g=r (0640) or less if owned by root\n"), + fnbuf); + return -1; + } +#endif + + if (SSL_use_PrivateKey_file(conn->ssl, fnbuf, SSL_FILETYPE_PEM) != 1) + { + char *err = SSLerrmessage(ERR_get_error()); + + /* + * We'll try to load the file in DER (binary ASN.1) format, and if + * that fails too, report the original error. This could mask + * issues where there's something wrong with a DER-format cert, + * but we'd have to duplicate openssl's format detection to be + * smarter than this. We can't just probe for a leading -----BEGIN + * because PEM can have leading non-matching lines and blanks. + * OpenSSL doesn't expose its get_name(...) and its PEM routines + * don't differentiate between failure modes in enough detail to + * let us tell the difference between "not PEM, try DER" and + * "wrong password". + */ + if (SSL_use_PrivateKey_file(conn->ssl, fnbuf, SSL_FILETYPE_ASN1) != 1) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("could not load private key file \"%s\": %s\n"), + fnbuf, err); + SSLerrfree(err); + return -1; + } + + SSLerrfree(err); + } + } + + /* verify that the cert and key go together */ + if (have_cert && + SSL_check_private_key(conn->ssl) != 1) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("certificate does not match private key file \"%s\": %s\n"), + fnbuf, err); + SSLerrfree(err); + return -1; + } + + /* + * If a root cert was loaded, also set our certificate verification + * callback. + */ + if (have_rootcert) + SSL_set_verify(conn->ssl, SSL_VERIFY_PEER, verify_cb); + + /* + * Set compression option if necessary. + */ + if (conn->sslcompression && conn->sslcompression[0] == '0') + SSL_set_options(conn->ssl, SSL_OP_NO_COMPRESSION); + else + SSL_clear_options(conn->ssl, SSL_OP_NO_COMPRESSION); + + return 0; +} + +/* + * Attempt to negotiate SSL connection. + */ +static PostgresPollingStatusType +open_client_SSL(PGconn *conn) +{ + int r; + + ERR_clear_error(); + r = SSL_connect(conn->ssl); + if (r <= 0) + { + int err = SSL_get_error(conn->ssl, r); + unsigned long ecode; + + ecode = ERR_get_error(); + switch (err) + { + case SSL_ERROR_WANT_READ: + return PGRES_POLLING_READING; + + case SSL_ERROR_WANT_WRITE: + return PGRES_POLLING_WRITING; + + case SSL_ERROR_SYSCALL: + { + char sebuf[PG_STRERROR_R_BUFLEN]; + + if (r == -1) + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSL SYSCALL error: %s\n"), + SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); + else + appendPQExpBufferStr(&conn->errorMessage, + libpq_gettext("SSL SYSCALL error: EOF detected\n")); + pgtls_close(conn); + return PGRES_POLLING_FAILED; + } + case SSL_ERROR_SSL: + { + char *err = SSLerrmessage(ecode); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSL error: %s\n"), + err); + SSLerrfree(err); + switch (ERR_GET_REASON(ecode)) + { + /* + * UNSUPPORTED_PROTOCOL, WRONG_VERSION_NUMBER, and + * TLSV1_ALERT_PROTOCOL_VERSION have been observed + * when trying to communicate with an old OpenSSL + * library, or when the client and server specify + * disjoint protocol ranges. + * NO_PROTOCOLS_AVAILABLE occurs if there's a + * local misconfiguration (which can happen + * despite our checks, if openssl.cnf injects a + * limit we didn't account for). It's not very + * clear what would make OpenSSL return the other + * codes listed here, but a hint about protocol + * versions seems like it's appropriate for all. + */ + case SSL_R_NO_PROTOCOLS_AVAILABLE: + case SSL_R_UNSUPPORTED_PROTOCOL: + case SSL_R_BAD_PROTOCOL_VERSION_NUMBER: + case SSL_R_UNKNOWN_PROTOCOL: + case SSL_R_UNKNOWN_SSL_VERSION: + case SSL_R_UNSUPPORTED_SSL_VERSION: + case SSL_R_WRONG_SSL_VERSION: + case SSL_R_WRONG_VERSION_NUMBER: + case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION: +#ifdef SSL_R_VERSION_TOO_HIGH + case SSL_R_VERSION_TOO_HIGH: + case SSL_R_VERSION_TOO_LOW: +#endif + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("This may indicate that the server does not support any SSL protocol version between %s and %s.\n"), + conn->ssl_min_protocol_version ? + conn->ssl_min_protocol_version : + MIN_OPENSSL_TLS_VERSION, + conn->ssl_max_protocol_version ? + conn->ssl_max_protocol_version : + MAX_OPENSSL_TLS_VERSION); + break; + default: + break; + } + pgtls_close(conn); + return PGRES_POLLING_FAILED; + } + + default: + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("unrecognized SSL error code: %d\n"), + err); + pgtls_close(conn); + return PGRES_POLLING_FAILED; + } + } + + /* + * We already checked the server certificate in initialize_SSL() using + * SSL_CTX_set_verify(), if root.crt exists. + */ + + /* get server certificate */ + conn->peer = SSL_get_peer_certificate(conn->ssl); + if (conn->peer == NULL) + { + char *err = SSLerrmessage(ERR_get_error()); + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("certificate could not be obtained: %s\n"), + err); + SSLerrfree(err); + pgtls_close(conn); + return PGRES_POLLING_FAILED; + } + + if (!pq_verify_peer_name_matches_certificate(conn)) + { + pgtls_close(conn); + return PGRES_POLLING_FAILED; + } + + /* SSL handshake is complete */ + return PGRES_POLLING_OK; +} + +void +pgtls_close(PGconn *conn) +{ + bool destroy_needed = false; + + if (conn->ssl_in_use) + { + if (conn->ssl) + { + /* + * We can't destroy everything SSL-related here due to the + * possible later calls to OpenSSL routines which may need our + * thread callbacks, so set a flag here and check at the end. + */ + + SSL_shutdown(conn->ssl); + SSL_free(conn->ssl); + conn->ssl = NULL; + conn->ssl_in_use = false; + + destroy_needed = true; + } + + if (conn->peer) + { + X509_free(conn->peer); + conn->peer = NULL; + } + +#ifdef USE_SSL_ENGINE + if (conn->engine) + { + ENGINE_finish(conn->engine); + ENGINE_free(conn->engine); + conn->engine = NULL; + } +#endif + } + else + { + /* + * In the non-SSL case, just remove the crypto callbacks if the + * connection has then loaded. This code path has no dependency on + * any pending SSL calls. + */ + if (conn->crypto_loaded) + destroy_needed = true; + } + + /* + * This will remove our crypto locking hooks if this is the last + * connection using libcrypto which means we must wait to call it until + * after all the potential SSL calls have been made, otherwise we can end + * up with a race condition and possible deadlocks. + * + * See comments above destroy_ssl_system(). + */ + if (destroy_needed) + { + destroy_ssl_system(); + conn->crypto_loaded = false; + } +} + + +/* + * Obtain reason string for passed SSL errcode + * + * ERR_get_error() is used by caller to get errcode to pass here. + * + * Some caution is needed here since ERR_reason_error_string will + * return NULL if it doesn't recognize the error code. We don't + * want to return NULL ever. + */ +static char ssl_nomem[] = "out of memory allocating error description"; + +#define SSL_ERR_LEN 128 + +static char * +SSLerrmessage(unsigned long ecode) +{ + const char *errreason; + char *errbuf; + + errbuf = malloc(SSL_ERR_LEN); + if (!errbuf) + return ssl_nomem; + if (ecode == 0) + { + snprintf(errbuf, SSL_ERR_LEN, libpq_gettext("no SSL error reported")); + return errbuf; + } + errreason = ERR_reason_error_string(ecode); + if (errreason != NULL) + { + strlcpy(errbuf, errreason, SSL_ERR_LEN); + return errbuf; + } + snprintf(errbuf, SSL_ERR_LEN, libpq_gettext("SSL error code %lu"), ecode); + return errbuf; +} + +static void +SSLerrfree(char *buf) +{ + if (buf != ssl_nomem) + free(buf); +} + +/* ------------------------------------------------------------ */ +/* SSL information functions */ +/* ------------------------------------------------------------ */ + +/* + * Return pointer to OpenSSL object. + */ +void * +PQgetssl(PGconn *conn) +{ + if (!conn) + return NULL; + return conn->ssl; +} + +void * +PQsslStruct(PGconn *conn, const char *struct_name) +{ + if (!conn) + return NULL; + if (strcmp(struct_name, "OpenSSL") == 0) + return conn->ssl; + return NULL; +} + +const char *const * +PQsslAttributeNames(PGconn *conn) +{ + static const char *const result[] = { + "library", + "key_bits", + "cipher", + "compression", + "protocol", + NULL + }; + + return result; +} + +const char * +PQsslAttribute(PGconn *conn, const char *attribute_name) +{ + if (!conn) + { + /* PQsslAttribute(NULL, "library") reports the default SSL library */ + if (strcmp(attribute_name, "library") == 0) + return "OpenSSL"; + return NULL; + } + + /* All attributes read as NULL for a non-encrypted connection */ + if (conn->ssl == NULL) + return NULL; + + if (strcmp(attribute_name, "library") == 0) + return "OpenSSL"; + + if (strcmp(attribute_name, "key_bits") == 0) + { + static char sslbits_str[12]; + int sslbits; + + SSL_get_cipher_bits(conn->ssl, &sslbits); + snprintf(sslbits_str, sizeof(sslbits_str), "%d", sslbits); + return sslbits_str; + } + + if (strcmp(attribute_name, "cipher") == 0) + return SSL_get_cipher(conn->ssl); + + if (strcmp(attribute_name, "compression") == 0) + return SSL_get_current_compression(conn->ssl) ? "on" : "off"; + + if (strcmp(attribute_name, "protocol") == 0) + return SSL_get_version(conn->ssl); + + return NULL; /* unknown attribute */ +} + +/* + * Private substitute BIO: this does the sending and receiving using + * pqsecure_raw_write() and pqsecure_raw_read() instead, to allow those + * functions to disable SIGPIPE and give better error messages on I/O errors. + * + * These functions are closely modelled on the standard socket BIO in OpenSSL; + * see sock_read() and sock_write() in OpenSSL's crypto/bio/bss_sock.c. + * XXX OpenSSL 1.0.1e considers many more errcodes than just EINTR as reasons + * to retry; do we need to adopt their logic for that? + */ + +#ifndef HAVE_BIO_GET_DATA +#define BIO_get_data(bio) (bio->ptr) +#define BIO_set_data(bio, data) (bio->ptr = data) +#endif + +static BIO_METHOD *my_bio_methods; + +static int +my_sock_read(BIO *h, char *buf, int size) +{ + int res; + + res = pqsecure_raw_read((PGconn *) BIO_get_data(h), buf, size); + BIO_clear_retry_flags(h); + if (res < 0) + { + /* If we were interrupted, tell caller to retry */ + switch (SOCK_ERRNO) + { +#ifdef EAGAIN + case EAGAIN: +#endif +#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN)) + case EWOULDBLOCK: +#endif + case EINTR: + BIO_set_retry_read(h); + break; + + default: + break; + } + } + + return res; +} + +static int +my_sock_write(BIO *h, const char *buf, int size) +{ + int res; + + res = pqsecure_raw_write((PGconn *) BIO_get_data(h), buf, size); + BIO_clear_retry_flags(h); + if (res < 0) + { + /* If we were interrupted, tell caller to retry */ + switch (SOCK_ERRNO) + { +#ifdef EAGAIN + case EAGAIN: +#endif +#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN)) + case EWOULDBLOCK: +#endif + case EINTR: + BIO_set_retry_write(h); + break; + + default: + break; + } + } + + return res; +} + +static BIO_METHOD * +my_BIO_s_socket(void) +{ + if (!my_bio_methods) + { + BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket(); +#ifdef HAVE_BIO_METH_NEW + int my_bio_index; + + my_bio_index = BIO_get_new_index(); + if (my_bio_index == -1) + return NULL; + my_bio_index |= (BIO_TYPE_DESCRIPTOR | BIO_TYPE_SOURCE_SINK); + my_bio_methods = BIO_meth_new(my_bio_index, "libpq socket"); + if (!my_bio_methods) + return NULL; + + /* + * As of this writing, these functions never fail. But check anyway, + * like OpenSSL's own examples do. + */ + if (!BIO_meth_set_write(my_bio_methods, my_sock_write) || + !BIO_meth_set_read(my_bio_methods, my_sock_read) || + !BIO_meth_set_gets(my_bio_methods, BIO_meth_get_gets(biom)) || + !BIO_meth_set_puts(my_bio_methods, BIO_meth_get_puts(biom)) || + !BIO_meth_set_ctrl(my_bio_methods, BIO_meth_get_ctrl(biom)) || + !BIO_meth_set_create(my_bio_methods, BIO_meth_get_create(biom)) || + !BIO_meth_set_destroy(my_bio_methods, BIO_meth_get_destroy(biom)) || + !BIO_meth_set_callback_ctrl(my_bio_methods, BIO_meth_get_callback_ctrl(biom))) + { + BIO_meth_free(my_bio_methods); + my_bio_methods = NULL; + return NULL; + } +#else + my_bio_methods = malloc(sizeof(BIO_METHOD)); + if (!my_bio_methods) + return NULL; + memcpy(my_bio_methods, biom, sizeof(BIO_METHOD)); + my_bio_methods->bread = my_sock_read; + my_bio_methods->bwrite = my_sock_write; +#endif + } + return my_bio_methods; +} + +/* This should exactly match OpenSSL's SSL_set_fd except for using my BIO */ +static int +my_SSL_set_fd(PGconn *conn, int fd) +{ + int ret = 0; + BIO *bio; + BIO_METHOD *bio_method; + + bio_method = my_BIO_s_socket(); + if (bio_method == NULL) + { + SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB); + goto err; + } + bio = BIO_new(bio_method); + if (bio == NULL) + { + SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB); + goto err; + } + BIO_set_data(bio, conn); + + SSL_set_bio(conn->ssl, bio, bio); + BIO_set_fd(bio, fd, BIO_NOCLOSE); + ret = 1; +err: + return ret; +} + +/* + * This is the default handler to return a client cert password from + * conn->sslpassword. Apps may install it explicitly if they want to + * prevent openssl from ever prompting on stdin. + */ +int +PQdefaultSSLKeyPassHook_OpenSSL(char *buf, int size, PGconn *conn) +{ + if (conn && conn->sslpassword) + { + if (strlen(conn->sslpassword) + 1 > size) + fprintf(stderr, libpq_gettext("WARNING: sslpassword truncated\n")); + strncpy(buf, conn->sslpassword, size); + buf[size - 1] = '\0'; + return strlen(buf); + } + else + { + buf[0] = '\0'; + return 0; + } +} + +PQsslKeyPassHook_OpenSSL_type +PQgetSSLKeyPassHook_OpenSSL(void) +{ + return PQsslKeyPassHook; +} + +void +PQsetSSLKeyPassHook_OpenSSL(PQsslKeyPassHook_OpenSSL_type hook) +{ + PQsslKeyPassHook = hook; +} + +/* + * Supply a password to decrypt a client certificate. + * + * This must match OpenSSL type pem_password_cb. + */ +static int +PQssl_passwd_cb(char *buf, int size, int rwflag, void *userdata) +{ + PGconn *conn = userdata; + + if (PQsslKeyPassHook) + return PQsslKeyPassHook(buf, size, conn); + else + return PQdefaultSSLKeyPassHook_OpenSSL(buf, size, conn); +} + +/* + * Convert TLS protocol version string to OpenSSL values + * + * If a version is passed that is not supported by the current OpenSSL version, + * then we return -1. If a non-negative value is returned, subsequent code can + * assume it is working with a supported version. + * + * Note: this is rather similar to the backend routine in be-secure-openssl.c, + * so make sure to update both routines if changing this one. + */ +static int +ssl_protocol_version_to_openssl(const char *protocol) +{ + if (pg_strcasecmp("TLSv1", protocol) == 0) + return TLS1_VERSION; + +#ifdef TLS1_1_VERSION + if (pg_strcasecmp("TLSv1.1", protocol) == 0) + return TLS1_1_VERSION; +#endif + +#ifdef TLS1_2_VERSION + if (pg_strcasecmp("TLSv1.2", protocol) == 0) + return TLS1_2_VERSION; +#endif + +#ifdef TLS1_3_VERSION + if (pg_strcasecmp("TLSv1.3", protocol) == 0) + return TLS1_3_VERSION; +#endif + + return -1; +} |