/*
* Given a hex encoded string, decode it into a chunk.
*
* If this function fails, crash and burn. It is fed static data
* so should never ever have a problem.
* The caller must free the chunk.
*/
chunk_t decode_hex_to_chunk(const char *original, const char *string)
{
/* The decoded buffer can't be bigger than half the encoded string. */
chunk_t chunk = zalloc_chunk((strlen(string)+1)/2, original);
chunk.len = 0;
const char *pos = string;
for (;;) {
/* skip leading/trailing space */
while (*pos == ' ') {
pos++;
}
if (*pos == '\0') {
break;
}
/* Expecting <HEX><HEX> */
char buf[3] = { '\0', '\0', '\0' };
if (isxdigit(*pos)) {
buf[0] = *pos++;
if (isxdigit(*pos)) {
buf[1] = *pos++;
}
}
if (buf[1] == '\0') {
PASSERT_FAIL("expected hex digit at offset %tu in hex buffer \"%s\" but found \"%.1s\"",
pos - string, string, pos);
}
char *end;
chunk.ptr[chunk.len] = strtoul(buf, &end, 16);
passert(*end == '\0');
chunk.len++;
}
return chunk;
}
/*
* Given an ASCII string, convert it onto a buffer of bytes. If the
* buffer is prefixed by 0x assume the contents are hex (with spaces)
* and decode it; otherwise it is assumed that the ascii (minus the
* NUL) should be copied.
*/
chunk_t decode_to_chunk(const char *prefix, const char *original)
{
DBG(DBG_CRYPT, DBG_log("decode_to_chunk: %s: input \"%s\"",
prefix, original));
chunk_t chunk;
if (startswith(original, "0x")) {
chunk = decode_hex_to_chunk(original, original + strlen("0x"));
} else {
chunk = zalloc_chunk(strlen(original), original);
memcpy(chunk.ptr, original, chunk.len);
}
DBG(DBG_CRYPT, DBG_dump_chunk("decode_to_chunk: output: ", chunk));
return chunk;
}
/*
* Given a hex encode string, decode it into a chunk.
*
* If this function fails, crash and burn. Its been fed static data
* so should never ever have a problem.
*/
chunk_t decode_hex_to_chunk(const char *original, const char *string)
{
/* The decoded buffer can't be bigger than the encoded string. */
chunk_t chunk = zalloc_chunk(strlen(string), original);
chunk.len = 0;
const char *pos = string;
while (*pos != '\0') {
/* skip leading/trailing space */
while (*pos == ' ') {
pos++;
}
if (*pos == '\0') {
break;
}
/* Expecting <HEX><HEX>, at least *pos is valid. */
char buf[3];
int i = 0;
do {
buf[i++] = *pos++;
} while (*pos != ' ' && *pos != '\0' && i < 2);
buf[i] = '\0';
if (i != 2) {
loglog(RC_INTERNALERR,
"decode_hex_to_chunk: hex buffer \"%s\" contains unexpected space or NUL at \"%s\"\n", string, pos);
exit_pluto(1);
}
char *end;
chunk.ptr[chunk.len] = strtoul(buf, &end, 16);
if (end - buf != 2) {
loglog(RC_INTERNALERR,
"decode_hex_to_chunk: hex buffer \"%s\" invalid hex character at \"%s\"\n", string, pos);
exit_pluto(1);
}
chunk.len++;
}
return chunk;
}