Mandatory Surgeon Guenther's Warning: This code could not possibly be

correct because it doesn't zerofill the front of usecs, but that's the
way I found it.
a more thorough emulation of the old code, but with fewer whacky snprintf
pointer arithmetic antics. ok beck guenther

diff --git a/lib/libcrypto/ts/ts_rsp_sign.c b/lib/libcrypto/ts/ts_rsp_sign.c
index b0f023c..235c0a8 100644 (file)
--- a/lib/libcrypto/ts/ts_rsp_sign.c
+++ b/lib/libcrypto/ts/ts_rsp_sign.c
@@ -953,8 +953,9 @@ TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
        time_t time_sec = (time_t) sec;
        struct tm *tm = NULL;   
        char genTime_str[17 + TS_MAX_CLOCK_PRECISION_DIGITS];
-       char *p = genTime_str;
-       char *p_end = genTime_str + sizeof(genTime_str);
+       char usecstr[TS_MAX_CLOCK_PRECISION_DIGITS + 2];
+       char *p;
+       int rv;
 
        if (precision > TS_MAX_CLOCK_PRECISION_DIGITS)
                goto err;
@@ -970,18 +971,7 @@ TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
         * meet the rfc3161 requirement: "GeneralizedTime syntax can include 
         * fraction-of-second details". 
         */                   
-       p += BIO_snprintf(p, p_end - p,
-                         "%04d%02d%02d%02d%02d%02d",
-                         tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
-                         tm->tm_hour, tm->tm_min, tm->tm_sec);
-       if (precision > 0)
-       {
-               /* Add fraction of seconds (leave space for dot and null). */
-               BIO_snprintf(p, 2 + precision, ".%ld", usec);
-               /* We cannot use the snprintf return value, 
-                  because it might have been truncated. */
-               p += strlen(p);
-
+       if (precision > 0) {
                /* To make things a bit harder, X.690 | ISO/IEC 8825-1 provides
                   the following restrictions for a DER-encoding, which OpenSSL
                   (specifically ASN1_GENERALIZEDTIME_check() function) doesn't 
@@ -993,16 +983,26 @@ TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
                   if the elements correspond to 0, they MUST be wholly
                   omitted, and the decimal point element also MUST be
                   omitted." */
-               /* Remove trailing zeros. The dot guarantees the exit
-                  condition of this loop even if all the digits are zero. */
-               while (*--p == '0')
-                       /* empty */;
-               /* p points to either the dot or the last non-zero digit. */
-               if (*p != '.') ++p;
-               }
-       /* Add the trailing Z and the terminating null. */
-       *p++ = 'Z';
-       *p++ = '\0';
+               (void)snprintf(usecstr, sizeof(usecstr), ".%ld", usec);
+               /* truncate and trim trailing 0 */
+               usecstr[precision + 1] = '\0';
+               p = usecstr + strlen(usecstr) - 1;
+               while (p > usecstr && *p == '0')
+                       *p-- = '\0';
+               /* if we've reached the beginning, delete the . too */
+               if (p == usecstr)
+                       *p = '\0';
+
+       } else {
+               /* empty */
+               usecstr[0] = '\0';
+       }
+       rv = snprintf(genTime_str, sizeof(genTime_str),
+           "%04d%02d%02d%02d%02d%02d%sZ",
+           tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
+           tm->tm_hour, tm->tm_min, tm->tm_sec, usecstr);
+       if (rv == -1 || rv >= sizeof(genTime_str))
+               goto err;
 
        /* Now call OpenSSL to check and set our genTime value */
        if (!asn1_time && !(asn1_time = M_ASN1_GENERALIZEDTIME_new()))

diff --git a/lib/libssl/src/crypto/ts/ts_rsp_sign.c b/lib/libssl/src/crypto/ts/ts_rsp_sign.c
index b0f023c..235c0a8 100644 (file)
--- a/lib/libssl/src/crypto/ts/ts_rsp_sign.c
+++ b/lib/libssl/src/crypto/ts/ts_rsp_sign.c
@@ -953,8 +953,9 @@ TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
        time_t time_sec = (time_t) sec;
        struct tm *tm = NULL;   
        char genTime_str[17 + TS_MAX_CLOCK_PRECISION_DIGITS];
-       char *p = genTime_str;
-       char *p_end = genTime_str + sizeof(genTime_str);
+       char usecstr[TS_MAX_CLOCK_PRECISION_DIGITS + 2];
+       char *p;
+       int rv;
 
        if (precision > TS_MAX_CLOCK_PRECISION_DIGITS)
                goto err;
@@ -970,18 +971,7 @@ TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
         * meet the rfc3161 requirement: "GeneralizedTime syntax can include 
         * fraction-of-second details". 
         */                   
-       p += BIO_snprintf(p, p_end - p,
-                         "%04d%02d%02d%02d%02d%02d",
-                         tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
-                         tm->tm_hour, tm->tm_min, tm->tm_sec);
-       if (precision > 0)
-       {
-               /* Add fraction of seconds (leave space for dot and null). */
-               BIO_snprintf(p, 2 + precision, ".%ld", usec);
-               /* We cannot use the snprintf return value, 
-                  because it might have been truncated. */
-               p += strlen(p);
-
+       if (precision > 0) {
                /* To make things a bit harder, X.690 | ISO/IEC 8825-1 provides
                   the following restrictions for a DER-encoding, which OpenSSL
                   (specifically ASN1_GENERALIZEDTIME_check() function) doesn't 
@@ -993,16 +983,26 @@ TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
                   if the elements correspond to 0, they MUST be wholly
                   omitted, and the decimal point element also MUST be
                   omitted." */
-               /* Remove trailing zeros. The dot guarantees the exit
-                  condition of this loop even if all the digits are zero. */
-               while (*--p == '0')
-                       /* empty */;
-               /* p points to either the dot or the last non-zero digit. */
-               if (*p != '.') ++p;
-               }
-       /* Add the trailing Z and the terminating null. */
-       *p++ = 'Z';
-       *p++ = '\0';
+               (void)snprintf(usecstr, sizeof(usecstr), ".%ld", usec);
+               /* truncate and trim trailing 0 */
+               usecstr[precision + 1] = '\0';
+               p = usecstr + strlen(usecstr) - 1;
+               while (p > usecstr && *p == '0')
+                       *p-- = '\0';
+               /* if we've reached the beginning, delete the . too */
+               if (p == usecstr)
+                       *p = '\0';
+
+       } else {
+               /* empty */
+               usecstr[0] = '\0';
+       }
+       rv = snprintf(genTime_str, sizeof(genTime_str),
+           "%04d%02d%02d%02d%02d%02d%sZ",
+           tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
+           tm->tm_hour, tm->tm_min, tm->tm_sec, usecstr);
+       if (rv == -1 || rv >= sizeof(genTime_str))
+               goto err;
 
        /* Now call OpenSSL to check and set our genTime value */
        if (!asn1_time && !(asn1_time = M_ASN1_GENERALIZEDTIME_new()))