diff options
Diffstat (limited to 'common/convert.c')
| -rw-r--r-- | common/convert.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/common/convert.c b/common/convert.c index e86ccecc7..6b0ff3548 100644 --- a/common/convert.c +++ b/common/convert.c @@ -175,21 +175,26 @@ bin2hexcolon (const void *buffer, size_t length, char *stringbuf) /* Convert HEXSTRING consisting of hex characters into string and store that at BUFFER. HEXSTRING is either delimited by end of string or a white space character. The function makes sure that - the resulting string in BUFFER is terminated by a Nul character. + the resulting string in BUFFER is terminated by a Nul byte. Note + that the retruned string may include embedded Nul bytes; the extra + Nul byte at the end is used to make sure tha the result can always + be used as a C-string. + BUFSIZE is the availabe length of BUFFER; if the converted result - plus a possible required Nul character does not fit into this + plus a possible required extra Nul character does not fit into this buffer, the function returns NULL and won't change the existing - conent of buffer. In-place conversion is possible as long as + content of BUFFER. In-place conversion is possible as long as BUFFER points to HEXSTRING. - If BUFFER is NULL and bufsize is 0 the function scans HEXSTRING but + If BUFFER is NULL and BUFSIZE is 0 the function scans HEXSTRING but does not store anything. This may be used to find the end of - hexstring. + HEXSTRING. On sucess the function returns a pointer to the next character after HEXSTRING (which is either end-of-string or a the next white - space). If BUFLEN is not NULL the strlen of buffer is stored - there; this will even be done if BUFFER has been passed as NULL. */ + space). If BUFLEN is not NULL the number of valid vytes in BUFFER + is stored there (an extra Nul byte is not counted); this will even + be done if BUFFER has been passed as NULL. */ const char * hex2str (const char *hexstring, char *buffer, size_t bufsize, size_t *buflen) { @@ -203,7 +208,10 @@ hex2str (const char *hexstring, char *buffer, size_t bufsize, size_t *buflen) for (s=hexstring, count=0; hexdigitp (s) && hexdigitp (s+1); s += 2, count++) ; if (*s && (!isascii (*s) || !isspace (*s)) ) - return NULL; /* Not followed by Nul or white space. */ + { + gpg_err_set_errno (EINVAL); + return NULL; /* Not followed by Nul or white space. */ + } /* We need to append a nul character. However we don't want that if the hexstring already ends with "00". */ need_nul = ((s == hexstring) || !(s[-2] == '0' && s[-1] == '0')); @@ -213,7 +221,10 @@ hex2str (const char *hexstring, char *buffer, size_t bufsize, size_t *buflen) if (buffer) { if (count > bufsize) - return NULL; /* Too long. */ + { + gpg_err_set_errno (EINVAL); + return NULL; /* Too long. */ + } for (s=hexstring, idx=0; hexdigitp (s) && hexdigitp (s+1); s += 2) ((unsigned char*)buffer)[idx++] = xtoi_2 (s); @@ -222,7 +233,7 @@ hex2str (const char *hexstring, char *buffer, size_t bufsize, size_t *buflen) } if (buflen) - *buflen = count - 1; + *buflen = count - need_nul; return s; } @@ -242,7 +253,6 @@ hex2str_alloc (const char *hexstring, size_t *r_count) { if (r_count) *r_count = 0; - gpg_err_set_errno (EINVAL); return NULL; } if (r_count) |