From ac9c3868c1cb3a2b2ece231061bcde48ffe1ae3c Mon Sep 17 00:00:00 2001 From: des Date: Fri, 5 Jul 2002 15:27:26 +0000 Subject: Rewrite to use the buffer API instead of roll-your-own messaging. Suggested by: Markus Friedl Sponsored by: DARPA, NAI Labs --- crypto/openssh/auth2-pam-freebsd.c | 181 +++++++++++++------------------------ 1 file changed, 65 insertions(+), 116 deletions(-) (limited to 'crypto') diff --git a/crypto/openssh/auth2-pam-freebsd.c b/crypto/openssh/auth2-pam-freebsd.c index b011913..9ce5988 100644 --- a/crypto/openssh/auth2-pam-freebsd.c +++ b/crypto/openssh/auth2-pam-freebsd.c @@ -39,8 +39,11 @@ RCSID("$FreeBSD$"); #include #include "auth.h" +#include "buffer.h" +#include "bufaux.h" #include "log.h" #include "monitor_wrap.h" +#include "msg.h" #include "packet.h" #include "ssh2.h" #include "xmalloc.h" @@ -55,72 +58,6 @@ struct pam_ctxt { static void pam_free_ctx(void *); /* - * Send message to parent or child. - */ -static int -pam_send(struct pam_ctxt *ctxt, char *fmt, ...) -{ - va_list ap; - char *mstr; - size_t len; - int r; - - va_start(ap, fmt); - len = vasprintf(&mstr, fmt, ap); - va_end(ap); - if (mstr == NULL) - exit(1); - if (ctxt->pam_pid != 0) - debug2("to child: %s", mstr); - r = send(ctxt->pam_sock, mstr, len + 1, MSG_EOR); - free(mstr); - return (r); -} - -/* - * Peek at first byte of next message. - */ -static int -pam_peek(struct pam_ctxt *ctxt) -{ - char ch; - - if (recv(ctxt->pam_sock, &ch, 1, MSG_PEEK) < 1) - return (-1); - return (ch); -} - -/* - * Receive a message from parent or child. - */ -static char * -pam_receive(struct pam_ctxt *ctxt) -{ - char *buf; - size_t len; - ssize_t rlen; - - len = 64; - buf = NULL; - do { - len *= 2; - buf = xrealloc(buf, len); - rlen = recv(ctxt->pam_sock, buf, len, MSG_PEEK); - if (rlen < 1) { - xfree(buf); - return (NULL); - } - } while (rlen == len); - if (recv(ctxt->pam_sock, buf, len, 0) != rlen) { - xfree(buf); - return (NULL); - } - if (ctxt->pam_pid != 0) - debug2("from child: %s", buf); - return (buf); -} - -/* * Conversation function for child process. */ static int @@ -129,42 +66,56 @@ pam_child_conv(int n, struct pam_response **resp, void *data) { + Buffer buffer; struct pam_ctxt *ctxt; int i; ctxt = data; if (n <= 0 || n > PAM_MAX_NUM_MSG) return (PAM_CONV_ERR); - if ((*resp = calloc(n, sizeof **resp)) == NULL) - return (PAM_BUF_ERR); + *resp = xmalloc(n * sizeof **resp); + buffer_init(&buffer); for (i = 0; i < n; ++i) { resp[i]->resp_retcode = 0; resp[i]->resp = NULL; switch (msg[i]->msg_style) { case PAM_PROMPT_ECHO_OFF: - pam_send(ctxt, "p%s", msg[i]->msg); - resp[i]->resp = pam_receive(ctxt); + buffer_put_cstring(&buffer, msg[i]->msg); + msg_send(ctxt->pam_sock, msg[i]->msg_style, &buffer); + msg_recv(ctxt->pam_sock, &buffer); + if (buffer_get_char(&buffer) != PAM_AUTHTOK) + goto fail; + resp[i]->resp = buffer_get_string(&buffer, NULL); break; case PAM_PROMPT_ECHO_ON: - pam_send(ctxt, "P%s", msg[i]->msg); - resp[i]->resp = pam_receive(ctxt); + buffer_put_cstring(&buffer, msg[i]->msg); + msg_send(ctxt->pam_sock, msg[i]->msg_style, &buffer); + msg_recv(ctxt->pam_sock, &buffer); + if (buffer_get_char(&buffer) != PAM_AUTHTOK) + goto fail; + resp[i]->resp = buffer_get_string(&buffer, NULL); break; case PAM_ERROR_MSG: - pam_send(ctxt, "e%s", msg[i]->msg); + buffer_put_cstring(&buffer, msg[i]->msg); + msg_send(ctxt->pam_sock, msg[i]->msg_style, &buffer); break; case PAM_TEXT_INFO: - pam_send(ctxt, "i%s", msg[i]->msg); + buffer_put_cstring(&buffer, msg[i]->msg); + msg_send(ctxt->pam_sock, msg[i]->msg_style, &buffer); break; default: goto fail; } + buffer_clear(&buffer); } + buffer_free(&buffer); return (PAM_SUCCESS); fail: while (i) - free(resp[--i]); - free(*resp); + xfree(resp[--i]); + xfree(*resp); *resp = NULL; + buffer_free(&buffer); return (PAM_CONV_ERR); } @@ -174,10 +125,13 @@ pam_child_conv(int n, static void * pam_child(struct pam_ctxt *ctxt) { + Buffer buffer; struct pam_conv pam_conv = { pam_child_conv, ctxt }; pam_handle_t *pamh; int pam_err; + buffer_init(&buffer); + setproctitle("%s [pam]", ctxt->pam_user); pam_err = pam_start("sshd", ctxt->pam_user, &pam_conv, &pamh); if (pam_err != PAM_SUCCESS) goto auth_fail; @@ -187,11 +141,15 @@ pam_child(struct pam_ctxt *ctxt) pam_err = pam_acct_mgmt(pamh, 0); if (pam_err != PAM_SUCCESS) goto auth_fail; - pam_send(ctxt, "=OK"); + buffer_put_cstring(&buffer, "OK"); + msg_send(ctxt->pam_sock, PAM_SUCCESS, &buffer); + buffer_free(&buffer); pam_end(pamh, pam_err); exit(0); auth_fail: - pam_send(ctxt, "!%s", pam_strerror(pamh, pam_err)); + buffer_put_cstring(&buffer, pam_strerror(pamh, pam_err)); + msg_send(ctxt->pam_sock, PAM_AUTH_ERR, &buffer); + buffer_free(&buffer); pam_end(pamh, pam_err); exit(0); } @@ -206,7 +164,7 @@ pam_init_ctx(Authctxt *authctxt) ctxt = xmalloc(sizeof *ctxt); ctxt->pam_user = xstrdup(authctxt->user); ctxt->pam_done = 0; - if (socketpair(AF_UNIX, SOCK_DGRAM, PF_UNSPEC, socks) == -1) { + if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { error("%s: failed create sockets: %s", __func__, strerror(errno)); xfree(ctxt); @@ -223,7 +181,7 @@ pam_init_ctx(Authctxt *authctxt) if (ctxt->pam_pid == 0) { /* close everything except our end of the pipe */ ctxt->pam_sock = socks[1]; - for (i = 0; i < getdtablesize(); ++i) + for (i = 3; i < getdtablesize(); ++i) if (i != ctxt->pam_sock) close(i); pam_child(ctxt); @@ -239,34 +197,40 @@ static int pam_query(void *ctx, char **name, char **info, u_int *num, char ***prompts, u_int **echo_on) { + Buffer buffer; struct pam_ctxt *ctxt = ctx; size_t plen; + u_char type; char *msg; + buffer_init(&buffer); *name = xstrdup(""); *info = xstrdup(""); *prompts = xmalloc(sizeof(char *)); **prompts = NULL; plen = 0; *echo_on = xmalloc(sizeof(u_int)); - while ((msg = pam_receive(ctxt)) != NULL) { - switch (*msg) { - case 'P': - case 'p': + while (msg_recv(ctxt->pam_sock, &buffer) == 0) { + type = buffer_get_char(&buffer); + msg = buffer_get_string(&buffer, NULL); + switch (type) { + case PAM_PROMPT_ECHO_ON: + case PAM_PROMPT_ECHO_OFF: *num = 1; - **prompts = xrealloc(**prompts, plen + strlen(msg)); - plen += sprintf(**prompts + plen, "%s", msg + 1); - **echo_on = (*msg == 'P'); + **prompts = xrealloc(**prompts, plen + strlen(msg) + 1); + plen += sprintf(**prompts + plen, "%s", msg); + **echo_on = (type == PAM_PROMPT_ECHO_ON); xfree(msg); return (0); - case 'e': - case 'i': + case PAM_ERROR_MSG: + case PAM_TEXT_INFO: /* accumulate messages */ - **prompts = xrealloc(**prompts, plen + strlen(msg)); - plen += sprintf(**prompts + plen, "%s", msg + 1); + **prompts = xrealloc(**prompts, plen + strlen(msg) + 1); + plen += sprintf(**prompts + plen, "%s", msg); + xfree(msg); break; - case '=': - case '!': + case PAM_SUCCESS: + case PAM_AUTH_ERR: if (**prompts != NULL) { /* drain any accumulated messages */ #if 0 /* not compatible with privsep */ @@ -279,14 +243,14 @@ pam_query(void *ctx, char **name, char **info, xfree(**prompts); **prompts = NULL; } - if (*msg == '=') { + if (type == PAM_SUCCESS) { *num = 0; **echo_on = 0; ctxt->pam_done = 1; xfree(msg); return (0); } - error("%s", msg + 1); + error("%s", msg); default: *num = 0; **echo_on = 0; @@ -294,7 +258,6 @@ pam_query(void *ctx, char **name, char **info, ctxt->pam_done = -1; return (-1); } - xfree(msg); } return (-1); } @@ -302,6 +265,7 @@ pam_query(void *ctx, char **name, char **info, static int pam_respond(void *ctx, u_int num, char **resp) { + Buffer buffer; struct pam_ctxt *ctxt = ctx; char *msg; @@ -318,26 +282,11 @@ pam_respond(void *ctx, u_int num, char **resp) error("expected one response, got %u", num); return (-1); } - pam_send(ctxt, "%s", *resp); - switch (pam_peek(ctxt)) { - case 'P': - case 'p': - case 'e': - case 'i': - return (1); - case '=': - msg = pam_receive(ctxt); - xfree(msg); - ctxt->pam_done = 1; - return (0); - default: - msg = pam_receive(ctxt); - if (*msg == '!') - error("%s", msg + 1); - xfree(msg); - ctxt->pam_done = -1; - return (-1); - } + buffer_init(&buffer); + buffer_put_cstring(&buffer, *resp); + msg_send(ctxt->pam_sock, PAM_AUTHTOK, &buffer); + buffer_free(&buffer); + return (1); } static void -- cgit v1.1