external/boringssl: Sync to 0726fb76ebe7f422e3c4fb2e25a0064926975770.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/9c33ae85621ef8e00a42309b5101e0bedd02b816..0726fb76ebe7f422e3c4fb2e25a0064926975770

Test: cts-tradefed run cts -m CtsLibcoreOkHttpTestCases -a arm64-v8a
Test: cts-tradefed run cts -m CtsLibcoreTestCases -a arm64-v8a

Change-Id: I6da679b1bbebffd35568794c7f6e45e2d620287b
diff --git a/src/crypto/x509/t_x509.c b/src/crypto/x509/t_x509.c
index d5d48ba..d4f6bba 100644
--- a/src/crypto/x509/t_x509.c
+++ b/src/crypto/x509/t_x509.c
@@ -54,6 +54,7 @@
  * copied and put under another distribution licence
  * [including the GNU Public Licence.] */
 
+#include <ctype.h>
 #include <openssl/asn1.h>
 #include <openssl/bio.h>
 #include <openssl/digest.h>
@@ -415,45 +416,84 @@
     return (0);
 }
 
-int ASN1_UTCTIME_print(BIO *bp, const ASN1_UTCTIME *tm)
-{
-    const char *v;
-    int gmt = 0;
-    int i;
-    int y = 0, M = 0, d = 0, h = 0, m = 0, s = 0;
+// consume_two_digits is a helper function for ASN1_UTCTIME_print. If |*v|,
+// assumed to be |*len| bytes long, has two leading digits, updates |*out| with
+// their value, updates |v| and |len|, and returns one. Otherwise, returns
+// zero.
+static int consume_two_digits(int* out, const char **v, int *len) {
+  if (*len < 2|| !isdigit((*v)[0]) || !isdigit((*v)[1])) {
+    return 0;
+  }
+  *out = ((*v)[0] - '0') * 10 + ((*v)[1] - '0');
+  *len -= 2;
+  *v += 2;
+  return 1;
+}
 
-    i = tm->length;
-    v = (const char *)tm->data;
+// consume_zulu_timezone is a helper function for ASN1_UTCTIME_print. If |*v|,
+// assumed to be |*len| bytes long, starts with "Z" then it updates |*v| and
+// |*len| and returns one. Otherwise returns zero.
+static int consume_zulu_timezone(const char **v, int *len) {
+  if (*len == 0 || (*v)[0] != 'Z') {
+    return 0;
+  }
 
-    if (i < 10)
-        goto err;
-    if (v[i - 1] == 'Z')
-        gmt = 1;
-    for (i = 0; i < 10; i++)
-        if ((v[i] > '9') || (v[i] < '0'))
-            goto err;
-    y = (v[0] - '0') * 10 + (v[1] - '0');
-    if (y < 50)
-        y += 100;
-    M = (v[2] - '0') * 10 + (v[3] - '0');
-    if ((M > 12) || (M < 1))
-        goto err;
-    d = (v[4] - '0') * 10 + (v[5] - '0');
-    h = (v[6] - '0') * 10 + (v[7] - '0');
-    m = (v[8] - '0') * 10 + (v[9] - '0');
-    if (tm->length >= 12 &&
-        (v[10] >= '0') && (v[10] <= '9') && (v[11] >= '0') && (v[11] <= '9'))
-        s = (v[10] - '0') * 10 + (v[11] - '0');
+  *len -= 1;
+  *v += 1;
+  return 1;
+}
 
-    if (BIO_printf(bp, "%s %2d %02d:%02d:%02d %d%s",
-                   mon[M - 1], d, h, m, s, y + 1900,
-                   (gmt) ? " GMT" : "") <= 0)
-        return (0);
-    else
-        return (1);
- err:
-    BIO_write(bp, "Bad time value", 14);
-    return (0);
+int ASN1_UTCTIME_print(BIO *bp, const ASN1_UTCTIME *tm) {
+  const char *v = (const char *)tm->data;
+  int len = tm->length;
+  int Y = 0, M = 0, D = 0, h = 0, m = 0, s = 0;
+
+  // YYMMDDhhmm are required to be present.
+  if (!consume_two_digits(&Y, &v, &len) ||
+      !consume_two_digits(&M, &v, &len) ||
+      !consume_two_digits(&D, &v, &len) ||
+      !consume_two_digits(&h, &v, &len) ||
+      !consume_two_digits(&m, &v, &len)) {
+    goto err;
+  }
+  // https://tools.ietf.org/html/rfc5280, section 4.1.2.5.1, requires seconds
+  // to be present, but historically this code has forgiven its absence.
+  consume_two_digits(&s, &v, &len);
+
+  // https://tools.ietf.org/html/rfc5280, section 4.1.2.5.1, specifies this
+  // interpretation of the year.
+  if (Y < 50) {
+    Y += 2000;
+  } else {
+    Y += 1900;
+  }
+  if (M > 12 || M == 0) {
+    goto err;
+  }
+  if (D > 31 || D == 0) {
+    goto err;
+  }
+  if (h > 23 || m > 59 || s > 60) {
+    goto err;
+  }
+
+  // https://tools.ietf.org/html/rfc5280, section 4.1.2.5.1, requires the "Z"
+  // to be present, but historically this code has forgiven its absence.
+  const int is_gmt = consume_zulu_timezone(&v, &len);
+
+  // https://tools.ietf.org/html/rfc5280, section 4.1.2.5.1, does not permit
+  // the specification of timezones using the +hhmm / -hhmm syntax, which is
+  // the only other thing that might legitimately be found at the end.
+  if (len) {
+    goto err;
+  }
+
+  return BIO_printf(bp, "%s %2d %02d:%02d:%02d %d%s", mon[M - 1], D, h, m, s, Y,
+                    is_gmt ? " GMT" : "") > 0;
+
+err:
+  BIO_write(bp, "Bad time value", 14);
+  return 0;
 }
 
 int X509_NAME_print(BIO *bp, X509_NAME *name, int obase)
diff --git a/src/crypto/x509/x509_test.cc b/src/crypto/x509/x509_test.cc
index 3629c13..4b80af8 100644
--- a/src/crypto/x509/x509_test.cc
+++ b/src/crypto/x509/x509_test.cc
@@ -17,6 +17,7 @@
 #include <assert.h>
 #include <string.h>
 
+#include <openssl/bio.h>
 #include <openssl/bytestring.h>
 #include <openssl/crypto.h>
 #include <openssl/digest.h>
@@ -1011,6 +1012,73 @@
   return true;
 }
 
+static bool TestPrintUTCTIME() {
+  static const struct {
+    const char *val, *want;
+  } asn1_utctime_tests[] = {
+    {"", "Bad time value"},
+
+    // Correct RFC 5280 form. Test years < 2000 and > 2000.
+    {"090303125425Z", "Mar  3 12:54:25 2009 GMT"},
+    {"900303125425Z", "Mar  3 12:54:25 1990 GMT"},
+    {"000303125425Z", "Mar  3 12:54:25 2000 GMT"},
+
+    // Correct form, bad values.
+    {"000000000000Z", "Bad time value"},
+    {"999999999999Z", "Bad time value"},
+
+    // Missing components. Not legal RFC 5280, but permitted.
+    {"090303125425", "Mar  3 12:54:25 2009"},
+    {"9003031254", "Mar  3 12:54:00 1990"},
+    {"9003031254Z", "Mar  3 12:54:00 1990 GMT"},
+
+    // GENERALIZEDTIME confused for UTCTIME.
+    {"20090303125425Z", "Bad time value"},
+
+    // Legal ASN.1, but not legal RFC 5280.
+    {"9003031254+0800", "Bad time value"},
+    {"9003031254-0800", "Bad time value"},
+
+    // Trailing garbage.
+    {"9003031254Z ", "Bad time value"},
+  };
+
+  for (auto t : asn1_utctime_tests) {
+    bssl::UniquePtr<ASN1_UTCTIME> tm(ASN1_UTCTIME_new());
+    bssl::UniquePtr<BIO> bio(BIO_new(BIO_s_mem()));
+
+    // Use this instead of ASN1_UTCTIME_set() because some callers get
+    // type-confused and pass ASN1_GENERALIZEDTIME to ASN1_UTCTIME_print().
+    // ASN1_UTCTIME_set_string() is stricter, and would reject the inputs in
+    // question.
+    if (!ASN1_STRING_set(tm.get(), t.val, strlen(t.val))) {
+      fprintf(stderr, "ASN1_STRING_set\n");
+      return false;
+    }
+    const int ok = ASN1_UTCTIME_print(bio.get(), tm.get());
+
+    const uint8_t *contents;
+    size_t len;
+    if (!BIO_mem_contents(bio.get(), &contents, &len)) {
+      fprintf(stderr, "BIO_mem_contents\n");
+      return false;
+    }
+
+    if (ok != (strcmp(t.want, "Bad time value") != 0)) {
+      fprintf(stderr, "ASN1_UTCTIME_print(%s): bad return value\n", t.val);
+      return false;
+    }
+    if (len != strlen(t.want) || memcmp(contents, t.want, len)) {
+      fprintf(stderr, "ASN1_UTCTIME_print(%s): got %.*s, want %s\n", t.val,
+              static_cast<int>(len),
+              reinterpret_cast<const char *>(contents), t.want);
+      return false;
+    }
+  }
+
+  return true;
+}
+
 int main() {
   CRYPTO_library_init();
 
@@ -1023,7 +1091,8 @@
       !TestFromBufferTrailingData() ||
       !TestFromBufferModified() ||
       !TestFromBufferReused() ||
-      !TestFailedParseFromBuffer()) {
+      !TestFailedParseFromBuffer() ||
+      !TestPrintUTCTIME()) {
     return 1;
   }