diff options
Diffstat (limited to 'sm/call-agent.c')
| -rw-r--r-- | sm/call-agent.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/sm/call-agent.c b/sm/call-agent.c index b37c2e53d..7ee728b74 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 +528,8 @@ gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc, return rc; } - put_membuf (&data, "", 1); /* Make sure it is 0 terminated. */ + /* Make sure it is 0 terminated so we can invoke strtoul safely. */ + put_membuf (&data, "", 1); buf = get_membuf (&data, &len); if (!buf) return gpg_error (GPG_ERR_ENOMEM); @@ -538,14 +539,20 @@ 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. */ - p = buf + 8; /* Skip leading parenthesis and the value tag. */ + /* 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 { /* For compatibility with older gpg-agents handle the old style - incomplete S-exps. */ - len--; /* Do not count the Nul. */ + incomplete S-exps. */ + len--; /* Do not count the Nul. */ p = buf; } @@ -553,8 +560,8 @@ gpgsm_agent_pkdecrypt (ctrl_t ctrl, const char *keygrip, const char *desc, if (!n || *endp != ':') return gpg_error (GPG_ERR_INV_SEXP); endp++; - if (endp-p+n > len) - return gpg_error (GPG_ERR_INV_SEXP); /* Oops: Inconsistent S-Exp. */ + if (endp-p+n != len) + return gpg_error (GPG_ERR_INV_SEXP); /* Oops: Inconsistent S-Exp. */ memmove (buf, endp, n); |