[PATCH 07/16] asn1: Implement asn1_write_definite_length

--- ell/asn1-private.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/ell/asn1-private.h b/ell/asn1-private.h index 0c5897a..bea9ea9 100644 --- a/ell/asn1-private.h +++ b/ell/asn1-private.h @@ -68,6 +68,22 @@ static inline int asn1_parse_definite_length(const uint8_t **buf, return result; } +static inline void asn1_write_definite_length(uint8_t **buf, size_t len) +{ + int n; + + if (len < 0x80) { + *(*buf)++ = len; + return; + } + + for (n = 1; len >> (n * 8); n++); + *(*buf)++ = 0x80 | n; + + while (n--) + *(*buf)++ = len >> (n * 8); +} + /* Return index'th element in a DER SEQUENCE */ static inline const uint8_t *asn1_der_find_elem(const uint8_t *buf, size_t len_in, int index, -- 2.19.1