diff --git a/g10/call-agent.c b/g10/call-agent.c index d55238311..62568fc76 100644 --- a/g10/call-agent.c +++ b/g10/call-agent.c @@ -2323,25 +2323,28 @@ agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc, return err; } - put_membuf (&data, "", 1); /* Make sure it is 0 terminated. */ buf = get_membuf (&data, &len); if (!buf) return gpg_error_from_syserror (); - log_assert (len); /* (we forced Nul termination.) */ - if (*buf != '(') + if (len == 0 || *buf != '(') { xfree (buf); return gpg_error (GPG_ERR_INV_SEXP); } - if (len < 13 || memcmp (buf, "(5:value", 8) ) /* "(5:valueN:D)\0" */ + if (len < 12 || memcmp (buf, "(5:value", 8) ) /* "(5:valueN:D)" */ { xfree (buf); return gpg_error (GPG_ERR_INV_SEXP); } - len -= 10; /* Count only the data of the second part. */ + while (buf[len-1] == 0) + len--; + if (buf[len-1] != ')') + return gpg_error (GPG_ERR_INV_SEXP); + len--; /* Drop the final close-paren. */ p = buf + 8; /* Skip leading parenthesis and the value tag. */ + len -= 8; /* Count only the data of the second part. */ n = strtoul (p, &endp, 10); if (!n || *endp != ':') diff --git a/sm/call-agent.c b/sm/call-agent.c index b37c2e53d..f9069a3b1 100644 --- a/sm/call-agent.c +++ b/sm/call-agent.c @@ -477,7 +477,7 @@ gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc, { int rc; char line[ASSUAN_LINELENGTH]; - membuf_t data; + membuf_t data; struct cipher_parm_s cipher_parm; size_t n, len; char *p, *buf, *endp; @@ -528,7 +528,7 @@ gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc, return rc; } - put_membuf (&data, "", 1); /* Make sure it is 0 terminated. */ + put_membuf (&data, "", 1); /* Make sure it is 0 terminated so we can invoke strtoul safely. */ buf = get_membuf (&data, &len); if (!buf) return gpg_error (GPG_ERR_ENOMEM); @@ -538,8 +538,14 @@ gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc, { if (len < 13 || memcmp (buf, "(5:value", 8) ) /* "(5:valueN:D)\0" */ return gpg_error (GPG_ERR_INV_SEXP); - len -= 11; /* Count only the data of the second part. */ + /* Trim any spurious trailing Nuls: */ + while (buf[len-1] == 0) + len--; + if (buf[len-1] != ')') + return gpg_error (GPG_ERR_INV_SEXP); + len--; /* Drop the final close-paren: */ p = buf + 8; /* Skip leading parenthesis and the value tag. */ + len -= 8; /* Count only the data of the second part. */ } else {