Make libcrypt thread-safe. Add crypt_r(3).

glibc has a pretty nice function called crypt_r(3), which is nothing
more than crypt(3), but thread-safe. It accomplishes this by introducing
a 'struct crypt_data' structure that contains a buffer that is large
enough to hold the resulting string.

Let's go ahead and also add this function. It would be a shame if a
useful function like this wouldn't be usable in multithreaded apps.
Refactor crypt.c and all of the backends to no longer declare static
arrays, but write their output in a provided buffer.

There is no need to do any buffer length computation here, as we'll just
need to ensure that 'struct crypt_data' is large enough, which it is.
_PASSWORD_LEN is defined to 128 bytes, but in this case I'm picking 256,
as this is going to be part of the actual ABI.

Differential Revision:	https://reviews.freebsd.org/D7306

1 files changed, 1 insertions, 3 deletions

diff --git a/lib/libcrypt/misc.c b/lib/libcrypt/misc.c
index 0f63ce04214c..2202ffb652cd 100644
--- a/lib/libcrypt/misc.c
+++ b/lib/libcrypt/misc.c
@@ -47,7 +47,7 @@ _crypt_to64(char *s, u_long v, int n)
 }
 
 void
-b64_from_24bit(uint8_t B2, uint8_t B1, uint8_t B0, int n, int *buflen, char **cp)
+b64_from_24bit(uint8_t B2, uint8_t B1, uint8_t B0, int n, char **cp)
 {
 	uint32_t w;
 	int i;
@@ -56,8 +56,6 @@ b64_from_24bit(uint8_t B2, uint8_t B1, uint8_t B0, int n, int *buflen, char **cp
 	for (i = 0; i < n; i++) {
 		**cp = itoa64[w&0x3f];
 		(*cp)++;
-		if ((*buflen)-- < 0)
-			break;
 		w >>= 6;
 	}
 }