From b7e011f8b6cf0dc5078932ebc3c06196b37e2a4c Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Mon, 31 Jul 2017 12:34:01 +0200 Subject: [PATCH] asn1/a_time.c: make handling of 'fractional point' formally correct. Even though tm->length >= 15 && v[14] == '.' works in practice, [because "YYYYMMDDHHMMSS." would be rejected as invalid by asn1_time_to_tm,] formal correctness with respect to buffer overstep in few lines vicinity improves readability. [Also fold one if condition and improve expression readability.] Reviewed-by: Rich Salz Reviewed-by: Richard Levitte (Merged from https://github.com/openssl/openssl/pull/4058) --- crypto/asn1/a_time.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) diff --git a/crypto/asn1/a_time.c b/crypto/asn1/a_time.c index b29aabeb51..b85f91760a 100644 --- a/crypto/asn1/a_time.c +++ b/crypto/asn1/a_time.c @@ -450,8 +450,7 @@ static const char _asn1_mon[12][4] = { int ASN1_TIME_print(BIO *bp, const ASN1_TIME *tm) { char *v; - char *f = NULL; - int f_len = 0, gmt = 0, l; + int gmt = 0, l; struct tm stm; if (!asn1_time_to_tm(&stm, tm)) { @@ -463,28 +462,32 @@ int ASN1_TIME_print(BIO *bp, const ASN1_TIME *tm) v = (char *)tm->data; if (v[l - 1] == 'Z') gmt = 1; - /* - * Try to parse fractional seconds. '14' is the place of - * 'fraction point' in a GeneralizedTime string. - */ - if (tm->type == V_ASN1_GENERALIZEDTIME - && tm->length >= 15 && v[14] == '.') { - f = &v[14]; - f_len = 1; - while (14 + f_len < l && f[f_len] >= '0' && f[f_len] <= '9') - ++f_len; - } - if (tm->type == V_ASN1_GENERALIZEDTIME) + if (tm->type == V_ASN1_GENERALIZEDTIME) { + char *f = NULL; + int f_len = 0; + + /* + * Try to parse fractional seconds. '14' is the place of + * 'fraction point' in a GeneralizedTime string. + */ + if (tm->length > 15 && v[14] == '.') { + f = &v[14]; + f_len = 1; + while (14 + f_len < l && f[f_len] >= '0' && f[f_len] <= '9') + ++f_len; + } + return BIO_printf(bp, "%s %2d %02d:%02d:%02d%.*s %d%s", _asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour, stm.tm_min, stm.tm_sec, f_len, f, stm.tm_year + 1900, - (gmt) ? " GMT" : "") > 0; - else + (gmt ? " GMT" : "")) > 0; + } else { return BIO_printf(bp, "%s %2d %02d:%02d:%02d %d%s", _asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour, stm.tm_min, stm.tm_sec, stm.tm_year + 1900, - (gmt) ? " GMT" : "") > 0; + (gmt ? " GMT" : "")) > 0; + } err: BIO_write(bp, "Bad time value", 14); return 0; -- 2.25.1