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Diffstat (limited to 'libpq/fe-auth.c')
| -rw-r--r-- | libpq/fe-auth.c | 841 |
1 files changed, 841 insertions, 0 deletions
diff --git a/libpq/fe-auth.c b/libpq/fe-auth.c new file mode 100644 index 0000000..ab057e9 --- /dev/null +++ b/libpq/fe-auth.c @@ -0,0 +1,841 @@ +/*------------------------------------------------------------------------- + * + * fe-auth.c + * The front-end (client) authorization routines + * + * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/interfaces/libpq/fe-auth.c + * + *------------------------------------------------------------------------- + */ + +/* + * INTERFACE ROUTINES + * frontend (client) routines: + * pg_fe_sendauth send authentication information + * pg_fe_getauthname get user's name according to the client side + * of the authentication system + */ + +#include "postgres_fe.h" + +#ifdef WIN32 +#include "win32.h" +#else +#include <unistd.h> +#include <fcntl.h> +#include <sys/param.h> /* for MAXHOSTNAMELEN on most */ +#include <sys/socket.h> +#ifdef HAVE_SYS_UCRED_H +#include <sys/ucred.h> +#endif +#ifndef MAXHOSTNAMELEN +#include <netdb.h> /* for MAXHOSTNAMELEN on some */ +#endif +#include <pwd.h> +#endif + +#include "libpq-fe.h" +#include "fe-auth.h" +#include "libpq/md5.h" + + +#ifdef ENABLE_GSS +/* + * GSSAPI authentication system. + */ + +#if defined(WIN32) && !defined(WIN32_ONLY_COMPILER) +/* + * MIT Kerberos GSSAPI DLL doesn't properly export the symbols for MingW + * that contain the OIDs required. Redefine here, values copied + * from src/athena/auth/krb5/src/lib/gssapi/generic/gssapi_generic.c + */ +static const gss_OID_desc GSS_C_NT_HOSTBASED_SERVICE_desc = +{10, (void *) "\x2a\x86\x48\x86\xf7\x12\x01\x02\x01\x04"}; +static GSS_DLLIMP gss_OID GSS_C_NT_HOSTBASED_SERVICE = &GSS_C_NT_HOSTBASED_SERVICE_desc; +#endif + +/* + * Fetch all errors of a specific type and append to "str". + */ +static void +pg_GSS_error_int(PQExpBuffer str, const char *mprefix, + OM_uint32 stat, int type) +{ + OM_uint32 lmin_s; + gss_buffer_desc lmsg; + OM_uint32 msg_ctx = 0; + + do + { + gss_display_status(&lmin_s, stat, type, + GSS_C_NO_OID, &msg_ctx, &lmsg); + appendPQExpBuffer(str, "%s: %s\n", mprefix, (char *) lmsg.value); + gss_release_buffer(&lmin_s, &lmsg); + } while (msg_ctx); +} + +/* + * GSSAPI errors contain two parts; put both into conn->errorMessage. + */ +static void +pg_GSS_error(const char *mprefix, PGconn *conn, + OM_uint32 maj_stat, OM_uint32 min_stat) +{ + resetPQExpBuffer(&conn->errorMessage); + + /* Fetch major error codes */ + pg_GSS_error_int(&conn->errorMessage, mprefix, maj_stat, GSS_C_GSS_CODE); + + /* Add the minor codes as well */ + pg_GSS_error_int(&conn->errorMessage, mprefix, min_stat, GSS_C_MECH_CODE); +} + +/* + * Continue GSS authentication with next token as needed. + */ +static int +pg_GSS_continue(PGconn *conn) +{ + OM_uint32 maj_stat, + min_stat, + lmin_s; + + maj_stat = gss_init_sec_context(&min_stat, + GSS_C_NO_CREDENTIAL, + &conn->gctx, + conn->gtarg_nam, + GSS_C_NO_OID, + GSS_C_MUTUAL_FLAG, + 0, + GSS_C_NO_CHANNEL_BINDINGS, + (conn->gctx == GSS_C_NO_CONTEXT) ? GSS_C_NO_BUFFER : &conn->ginbuf, + NULL, + &conn->goutbuf, + NULL, + NULL); + + if (conn->gctx != GSS_C_NO_CONTEXT) + { + free(conn->ginbuf.value); + conn->ginbuf.value = NULL; + conn->ginbuf.length = 0; + } + + if (conn->goutbuf.length != 0) + { + /* + * GSS generated data to send to the server. We don't care if it's the + * first or subsequent packet, just send the same kind of password + * packet. + */ + if (pqPacketSend(conn, 'p', + conn->goutbuf.value, conn->goutbuf.length) + != STATUS_OK) + { + gss_release_buffer(&lmin_s, &conn->goutbuf); + return STATUS_ERROR; + } + } + gss_release_buffer(&lmin_s, &conn->goutbuf); + + if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) + { + pg_GSS_error(libpq_gettext("GSSAPI continuation error"), + conn, + maj_stat, min_stat); + gss_release_name(&lmin_s, &conn->gtarg_nam); + if (conn->gctx) + gss_delete_sec_context(&lmin_s, &conn->gctx, GSS_C_NO_BUFFER); + return STATUS_ERROR; + } + + if (maj_stat == GSS_S_COMPLETE) + gss_release_name(&lmin_s, &conn->gtarg_nam); + + return STATUS_OK; +} + +/* + * Send initial GSS authentication token + */ +static int +pg_GSS_startup(PGconn *conn) +{ + OM_uint32 maj_stat, + min_stat; + int maxlen; + gss_buffer_desc temp_gbuf; + + if (!(conn->pghost && conn->pghost[0] != '\0')) + { + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("host name must be specified\n")); + return STATUS_ERROR; + } + + if (conn->gctx) + { + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("duplicate GSS authentication request\n")); + return STATUS_ERROR; + } + + /* + * Import service principal name so the proper ticket can be acquired by + * the GSSAPI system. + */ + maxlen = NI_MAXHOST + strlen(conn->krbsrvname) + 2; + temp_gbuf.value = (char *) malloc(maxlen); + if (!temp_gbuf.value) + { + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("out of memory\n")); + return STATUS_ERROR; + } + snprintf(temp_gbuf.value, maxlen, "%s@%s", + conn->krbsrvname, conn->pghost); + temp_gbuf.length = strlen(temp_gbuf.value); + + maj_stat = gss_import_name(&min_stat, &temp_gbuf, + GSS_C_NT_HOSTBASED_SERVICE, &conn->gtarg_nam); + free(temp_gbuf.value); + + if (maj_stat != GSS_S_COMPLETE) + { + pg_GSS_error(libpq_gettext("GSSAPI name import error"), + conn, + maj_stat, min_stat); + return STATUS_ERROR; + } + + /* + * Initial packet is the same as a continuation packet with no initial + * context. + */ + conn->gctx = GSS_C_NO_CONTEXT; + + return pg_GSS_continue(conn); +} +#endif /* ENABLE_GSS */ + + +#ifdef ENABLE_SSPI +/* + * SSPI authentication system (Windows only) + */ + +static void +pg_SSPI_error(PGconn *conn, const char *mprefix, SECURITY_STATUS r) +{ + char sysmsg[256]; + + if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | + FORMAT_MESSAGE_FROM_SYSTEM, + NULL, r, 0, + sysmsg, sizeof(sysmsg), NULL) == 0) + printfPQExpBuffer(&conn->errorMessage, "%s: SSPI error %x\n", + mprefix, (unsigned int) r); + else + printfPQExpBuffer(&conn->errorMessage, "%s: %s (%x)\n", + mprefix, sysmsg, (unsigned int) r); +} + +/* + * Continue SSPI authentication with next token as needed. + */ +static int +pg_SSPI_continue(PGconn *conn) +{ + SECURITY_STATUS r; + CtxtHandle newContext; + ULONG contextAttr; + SecBufferDesc inbuf; + SecBufferDesc outbuf; + SecBuffer OutBuffers[1]; + SecBuffer InBuffers[1]; + + if (conn->sspictx != NULL) + { + /* + * On runs other than the first we have some data to send. Put this + * data in a SecBuffer type structure. + */ + inbuf.ulVersion = SECBUFFER_VERSION; + inbuf.cBuffers = 1; + inbuf.pBuffers = InBuffers; + InBuffers[0].pvBuffer = conn->ginbuf.value; + InBuffers[0].cbBuffer = conn->ginbuf.length; + InBuffers[0].BufferType = SECBUFFER_TOKEN; + } + + OutBuffers[0].pvBuffer = NULL; + OutBuffers[0].BufferType = SECBUFFER_TOKEN; + OutBuffers[0].cbBuffer = 0; + outbuf.cBuffers = 1; + outbuf.pBuffers = OutBuffers; + outbuf.ulVersion = SECBUFFER_VERSION; + + r = InitializeSecurityContext(conn->sspicred, + conn->sspictx, + conn->sspitarget, + ISC_REQ_ALLOCATE_MEMORY, + 0, + SECURITY_NETWORK_DREP, + (conn->sspictx == NULL) ? NULL : &inbuf, + 0, + &newContext, + &outbuf, + &contextAttr, + NULL); + + if (r != SEC_E_OK && r != SEC_I_CONTINUE_NEEDED) + { + pg_SSPI_error(conn, libpq_gettext("SSPI continuation error"), r); + + return STATUS_ERROR; + } + + if (conn->sspictx == NULL) + { + /* On first run, transfer retrieved context handle */ + conn->sspictx = malloc(sizeof(CtxtHandle)); + if (conn->sspictx == NULL) + { + printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory\n")); + return STATUS_ERROR; + } + memcpy(conn->sspictx, &newContext, sizeof(CtxtHandle)); + } + else + { + /* + * On subsequent runs when we had data to send, free buffers that + * contained this data. + */ + free(conn->ginbuf.value); + conn->ginbuf.value = NULL; + conn->ginbuf.length = 0; + } + + /* + * If SSPI returned any data to be sent to the server (as it normally + * would), send this data as a password packet. + */ + if (outbuf.cBuffers > 0) + { + if (outbuf.cBuffers != 1) + { + /* + * This should never happen, at least not for Kerberos + * authentication. Keep check in case it shows up with other + * authentication methods later. + */ + printfPQExpBuffer(&conn->errorMessage, "SSPI returned invalid number of output buffers\n"); + return STATUS_ERROR; + } + + /* + * If the negotiation is complete, there may be zero bytes to send. + * The server is at this point not expecting any more data, so don't + * send it. + */ + if (outbuf.pBuffers[0].cbBuffer > 0) + { + if (pqPacketSend(conn, 'p', + outbuf.pBuffers[0].pvBuffer, outbuf.pBuffers[0].cbBuffer)) + { + FreeContextBuffer(outbuf.pBuffers[0].pvBuffer); + return STATUS_ERROR; + } + } + FreeContextBuffer(outbuf.pBuffers[0].pvBuffer); + } + + /* Cleanup is handled by the code in freePGconn() */ + return STATUS_OK; +} + +/* + * Send initial SSPI authentication token. + * If use_negotiate is 0, use kerberos authentication package which is + * compatible with Unix. If use_negotiate is 1, use the negotiate package + * which supports both kerberos and NTLM, but is not compatible with Unix. + */ +static int +pg_SSPI_startup(PGconn *conn, int use_negotiate) +{ + SECURITY_STATUS r; + TimeStamp expire; + + if (conn->sspictx) + { + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("duplicate SSPI authentication request\n")); + return STATUS_ERROR; + } + + /* + * Retrieve credentials handle + */ + conn->sspicred = malloc(sizeof(CredHandle)); + if (conn->sspicred == NULL) + { + printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory\n")); + return STATUS_ERROR; + } + + r = AcquireCredentialsHandle(NULL, + use_negotiate ? "negotiate" : "kerberos", + SECPKG_CRED_OUTBOUND, + NULL, + NULL, + NULL, + NULL, + conn->sspicred, + &expire); + if (r != SEC_E_OK) + { + pg_SSPI_error(conn, libpq_gettext("could not acquire SSPI credentials"), r); + free(conn->sspicred); + conn->sspicred = NULL; + return STATUS_ERROR; + } + + /* + * Compute target principal name. SSPI has a different format from GSSAPI, + * but not more complex. We can skip the @REALM part, because Windows will + * fill that in for us automatically. + */ + if (!(conn->pghost && conn->pghost[0] != '\0')) + { + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("host name must be specified\n")); + return STATUS_ERROR; + } + conn->sspitarget = malloc(strlen(conn->krbsrvname) + strlen(conn->pghost) + 2); + if (!conn->sspitarget) + { + printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory\n")); + return STATUS_ERROR; + } + sprintf(conn->sspitarget, "%s/%s", conn->krbsrvname, conn->pghost); + + /* + * Indicate that we're in SSPI authentication mode to make sure that + * pg_SSPI_continue is called next time in the negotiation. + */ + conn->usesspi = 1; + + return pg_SSPI_continue(conn); +} +#endif /* ENABLE_SSPI */ + +/* + * Respond to AUTH_REQ_SCM_CREDS challenge. + * + * Note: this is dead code as of Postgres 9.1, because current backends will + * never send this challenge. But we must keep it as long as libpq needs to + * interoperate with pre-9.1 servers. It is believed to be needed only on + * Debian/kFreeBSD (ie, FreeBSD kernel with Linux userland, so that the + * getpeereid() function isn't provided by libc). + */ +static int +pg_local_sendauth(PGconn *conn) +{ +#ifdef HAVE_STRUCT_CMSGCRED + char buf; + struct iovec iov; + struct msghdr msg; + struct cmsghdr *cmsg; + union + { + struct cmsghdr hdr; + unsigned char buf[CMSG_SPACE(sizeof(struct cmsgcred))]; + } cmsgbuf; + + /* + * The backend doesn't care what we send here, but it wants exactly one + * character to force recvmsg() to block and wait for us. + */ + buf = '\0'; + iov.iov_base = &buf; + iov.iov_len = 1; + + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + + /* We must set up a message that will be filled in by kernel */ + memset(&cmsgbuf, 0, sizeof(cmsgbuf)); + msg.msg_control = &cmsgbuf.buf; + msg.msg_controllen = sizeof(cmsgbuf.buf); + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_len = CMSG_LEN(sizeof(struct cmsgcred)); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_CREDS; + + if (sendmsg(conn->sock, &msg, 0) == -1) + { + char sebuf[256]; + + printfPQExpBuffer(&conn->errorMessage, + "pg_local_sendauth: sendmsg: %s\n", + pqStrerror(errno, sebuf, sizeof(sebuf))); + return STATUS_ERROR; + } + return STATUS_OK; +#else + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("SCM_CRED authentication method not supported\n")); + return STATUS_ERROR; +#endif +} + +static int +pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq) +{ + int ret; + char *crypt_pwd = NULL; + const char *pwd_to_send; + + /* Encrypt the password if needed. */ + + switch (areq) + { + case AUTH_REQ_MD5: + { + char *crypt_pwd2; + + /* Allocate enough space for two MD5 hashes */ + crypt_pwd = malloc(2 * (MD5_PASSWD_LEN + 1)); + if (!crypt_pwd) + { + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("out of memory\n")); + return STATUS_ERROR; + } + + crypt_pwd2 = crypt_pwd + MD5_PASSWD_LEN + 1; + if (!pg_md5_encrypt(password, conn->pguser, + strlen(conn->pguser), crypt_pwd2)) + { + free(crypt_pwd); + return STATUS_ERROR; + } + if (!pg_md5_encrypt(crypt_pwd2 + strlen("md5"), conn->md5Salt, + sizeof(conn->md5Salt), crypt_pwd)) + { + free(crypt_pwd); + return STATUS_ERROR; + } + + pwd_to_send = crypt_pwd; + break; + } + case AUTH_REQ_PASSWORD: + pwd_to_send = password; + break; + default: + return STATUS_ERROR; + } + /* Packet has a message type as of protocol 3.0 */ + if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3) + ret = pqPacketSend(conn, 'p', pwd_to_send, strlen(pwd_to_send) + 1); + else + ret = pqPacketSend(conn, 0, pwd_to_send, strlen(pwd_to_send) + 1); + if (crypt_pwd) + free(crypt_pwd); + return ret; +} + +/* + * pg_fe_sendauth + * client demux routine for outgoing authentication information + */ +int +pg_fe_sendauth(AuthRequest areq, PGconn *conn) +{ + switch (areq) + { + case AUTH_REQ_OK: + break; + + case AUTH_REQ_KRB4: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("Kerberos 4 authentication not supported\n")); + return STATUS_ERROR; + + case AUTH_REQ_KRB5: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("Kerberos 5 authentication not supported\n")); + return STATUS_ERROR; + +#if defined(ENABLE_GSS) || defined(ENABLE_SSPI) + case AUTH_REQ_GSS: +#if !defined(ENABLE_SSPI) + /* no native SSPI, so use GSSAPI library for it */ + case AUTH_REQ_SSPI: +#endif + { + int r; + + pglock_thread(); + + /* + * If we have both GSS and SSPI support compiled in, use SSPI + * support by default. This is overridable by a connection + * string parameter. Note that when using SSPI we still leave + * the negotiate parameter off, since we want SSPI to use the + * GSSAPI kerberos protocol. For actual SSPI negotiate + * protocol, we use AUTH_REQ_SSPI. + */ +#if defined(ENABLE_GSS) && defined(ENABLE_SSPI) + if (conn->gsslib && (pg_strcasecmp(conn->gsslib, "gssapi") == 0)) + r = pg_GSS_startup(conn); + else + r = pg_SSPI_startup(conn, 0); +#elif defined(ENABLE_GSS) && !defined(ENABLE_SSPI) + r = pg_GSS_startup(conn); +#elif !defined(ENABLE_GSS) && defined(ENABLE_SSPI) + r = pg_SSPI_startup(conn, 0); +#endif + if (r != STATUS_OK) + { + /* Error message already filled in. */ + pgunlock_thread(); + return STATUS_ERROR; + } + pgunlock_thread(); + } + break; + + case AUTH_REQ_GSS_CONT: + { + int r; + + pglock_thread(); +#if defined(ENABLE_GSS) && defined(ENABLE_SSPI) + if (conn->usesspi) + r = pg_SSPI_continue(conn); + else + r = pg_GSS_continue(conn); +#elif defined(ENABLE_GSS) && !defined(ENABLE_SSPI) + r = pg_GSS_continue(conn); +#elif !defined(ENABLE_GSS) && defined(ENABLE_SSPI) + r = pg_SSPI_continue(conn); +#endif + if (r != STATUS_OK) + { + /* Error message already filled in. */ + pgunlock_thread(); + return STATUS_ERROR; + } + pgunlock_thread(); + } + break; +#else /* defined(ENABLE_GSS) || defined(ENABLE_SSPI) */ + /* No GSSAPI *or* SSPI support */ + case AUTH_REQ_GSS: + case AUTH_REQ_GSS_CONT: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("GSSAPI authentication not supported\n")); + return STATUS_ERROR; +#endif /* defined(ENABLE_GSS) || defined(ENABLE_SSPI) */ + +#ifdef ENABLE_SSPI + case AUTH_REQ_SSPI: + + /* + * SSPI has it's own startup message so libpq can decide which + * method to use. Indicate to pg_SSPI_startup that we want SSPI + * negotiation instead of Kerberos. + */ + pglock_thread(); + if (pg_SSPI_startup(conn, 1) != STATUS_OK) + { + /* Error message already filled in. */ + pgunlock_thread(); + return STATUS_ERROR; + } + pgunlock_thread(); + break; +#else + + /* + * No SSPI support. However, if we have GSSAPI but not SSPI + * support, AUTH_REQ_SSPI will have been handled in the codepath + * for AUTH_REQ_GSSAPI above, so don't duplicate the case label in + * that case. + */ +#if !defined(ENABLE_GSS) + case AUTH_REQ_SSPI: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("SSPI authentication not supported\n")); + return STATUS_ERROR; +#endif /* !define(ENABLE_GSSAPI) */ +#endif /* ENABLE_SSPI */ + + + case AUTH_REQ_CRYPT: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("Crypt authentication not supported\n")); + return STATUS_ERROR; + + case AUTH_REQ_MD5: + case AUTH_REQ_PASSWORD: + conn->password_needed = true; + if (conn->pgpass == NULL || conn->pgpass[0] == '\0') + { + printfPQExpBuffer(&conn->errorMessage, + PQnoPasswordSupplied); + return STATUS_ERROR; + } + if (pg_password_sendauth(conn, conn->pgpass, areq) != STATUS_OK) + { + printfPQExpBuffer(&conn->errorMessage, + "fe_sendauth: error sending password authentication\n"); + return STATUS_ERROR; + } + break; + + case AUTH_REQ_SCM_CREDS: + if (pg_local_sendauth(conn) != STATUS_OK) + return STATUS_ERROR; + break; + + /* + * SASL authentication was introduced in version 10. Older + * versions recognize the request only to give a nicer error + * message. We call it "SCRAM authentication" in the error, rather + * than SASL, because SCRAM is more familiar to users, and it's + * the only SASL authentication mechanism that has been + * implemented as of this writing, anyway. + */ + case AUTH_REQ_SASL: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("SCRAM authentication requires libpq version 10 or above\n")); + return STATUS_ERROR; + + default: + printfPQExpBuffer(&conn->errorMessage, + libpq_gettext("authentication method %u not supported\n"), areq); + return STATUS_ERROR; + } + + return STATUS_OK; +} + + +/* + * pg_fe_getauthname + * + * Returns a pointer to malloc'd space containing whatever name the user + * has authenticated to the system. If there is an error, return NULL, + * and put a suitable error message in *errorMessage if that's not NULL. + */ +char * +pg_fe_getauthname(PQExpBuffer errorMessage) +{ + char *result = NULL; + const char *name = NULL; + +#ifdef WIN32 + /* Microsoft recommends buffer size of UNLEN+1, where UNLEN = 256 */ + char username[256 + 1]; + DWORD namesize = sizeof(username); +#else + uid_t user_id = geteuid(); + char pwdbuf[BUFSIZ]; + struct passwd pwdstr; + struct passwd *pw = NULL; + int pwerr; +#endif + + /* + * Some users are using configure --enable-thread-safety-force, so we + * might as well do the locking within our library to protect + * pqGetpwuid(). In fact, application developers can use getpwuid() in + * their application if they use the locking call we provide, or install + * their own locking function using PQregisterThreadLock(). + */ + pglock_thread(); + +#ifdef WIN32 + if (GetUserName(username, &namesize)) + name = username; + else if (errorMessage) + printfPQExpBuffer(errorMessage, + libpq_gettext("user name lookup failure: error code %lu\n"), + GetLastError()); +#else + pwerr = pqGetpwuid(user_id, &pwdstr, pwdbuf, sizeof(pwdbuf), &pw); + if (pw != NULL) + name = pw->pw_name; + else if (errorMessage) + { + if (pwerr != 0) + printfPQExpBuffer(errorMessage, + libpq_gettext("could not look up local user ID %d: %s\n"), + (int) user_id, + pqStrerror(pwerr, pwdbuf, sizeof(pwdbuf))); + else + printfPQExpBuffer(errorMessage, + libpq_gettext("local user with ID %d does not exist\n"), + (int) user_id); + } +#endif + + if (name) + { + result = strdup(name); + if (result == NULL && errorMessage) + printfPQExpBuffer(errorMessage, + libpq_gettext("out of memory\n")); + } + + pgunlock_thread(); + + return result; +} + + +/* + * PQencryptPassword -- exported routine to encrypt a password + * + * This is intended to be used by client applications that wish to send + * commands like ALTER USER joe PASSWORD 'pwd'. The password need not + * be sent in cleartext if it is encrypted on the client side. This is + * good because it ensures the cleartext password won't end up in logs, + * pg_stat displays, etc. We export the function so that clients won't + * be dependent on low-level details like whether the encryption is MD5 + * or something else. + * + * Arguments are the cleartext password, and the SQL name of the user it + * is for. + * + * Return value is a malloc'd string, or NULL if out-of-memory. The client + * may assume the string doesn't contain any special characters that would + * require escaping. + */ +char * +PQencryptPassword(const char *passwd, const char *user) +{ + char *crypt_pwd; + + crypt_pwd = malloc(MD5_PASSWD_LEN + 1); + if (!crypt_pwd) + return NULL; + + if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd)) + { + free(crypt_pwd); + return NULL; + } + + return crypt_pwd; +} |