diff options
Diffstat (limited to 'src/lib/krb5/asn.1/asn1_decode.c')
-rw-r--r-- | src/lib/krb5/asn.1/asn1_decode.c | 46 |
1 files changed, 45 insertions, 1 deletions
diff --git a/src/lib/krb5/asn.1/asn1_decode.c b/src/lib/krb5/asn.1/asn1_decode.c index 56904c5ee..65863202a 100644 --- a/src/lib/krb5/asn.1/asn1_decode.c +++ b/src/lib/krb5/asn.1/asn1_decode.c @@ -1,7 +1,7 @@ /* * src/lib/krb5/asn.1/asn1_decode.c * - * Copyright 1994 by the Massachusetts Institute of Technology. + * Copyright 1994, 2003 by the Massachusetts Institute of Technology. * All Rights Reserved. * * Export of this software from the United States of America may @@ -106,6 +106,50 @@ asn1_error_code asn1_decode_unsigned_integer(asn1buf *buf, long unsigned int *va cleanup(); } +/* + * asn1_decode_maybe_unsigned + * + * This is needed because older releases of MIT krb5 have signed + * sequence numbers. We want to accept both signed and unsigned + * sequence numbers, in the range -2^31..2^32-1, mapping negative + * numbers into their positive equivalents in the same way that C's + * normal integer conversions do, i.e., would preserve bits on a + * two's-complement architecture. + */ +asn1_error_code asn1_decode_maybe_unsigned(asn1buf *buf, unsigned long *val) +{ + setup(); + asn1_octet o; + unsigned long n, bitsremain; + unsigned int i; + + tag(ASN1_INTEGER); + o = 0; + n = 0; + bitsremain = ~0UL; + for (i = 0; i < length; i++) { + /* Accounts for u_long width not being a multiple of 8. */ + if (bitsremain < 0xff) return ASN1_OVERFLOW; + retval = asn1buf_remove_octet(buf, &o); + if (retval) return retval; + if (bitsremain == ~0UL) { + if (i == 0) + n = (o & 0x80) ? ~0UL : 0UL; /* grab sign bit */ + /* + * Skip leading zero or 0xFF octets to humor non-compliant encoders. + */ + if (n == 0 && o == 0) + continue; + if (n == ~0UL && o == 0xff) + continue; + } + n = (n << 8) | o; + bitsremain >>= 8; + } + *val = n; + cleanup(); +} + asn1_error_code asn1_decode_oid(asn1buf *buf, unsigned int *retlen, asn1_octet **val) { setup(); |