1 files changed, 91 insertions, 0 deletions
diff --git a/server/resty/openssl/asn1.lua b/server/resty/openssl/asn1.lua
new file mode 100644
index 0000000..0fa0605
--- /dev/null
+++ b/server/resty/openssl/asn1.lua
@@ -0,0 +1,91 @@
+local ffi = require "ffi"
+local C = ffi.C
+local ffi_str = ffi.string
+local floor = math.floor
+
+local asn1_macro = require("resty.openssl.include.asn1")
+
+-- https://github.com/wahern/luaossl/blob/master/src/openssl.c
+local function isleap(year)
+  return (year % 4) == 0 and ((year % 100) > 0 or (year % 400) == 0)
+end
+
+local past = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }
+local function yday(year, mon, mday)
+  local d = past[mon] + mday - 1
+  if mon > 2 and isleap(year) then
+    d = d + 1
+  end
+  return d
+end
+
+local function leaps(year)
+  return floor(year / 400) + floor(year / 4) - floor(year / 100)
+end
+
+local function asn1_to_unix(asn1)
+  if asn1 == nil then
+    return nil, "except an ASN1 instance at #1, got nil"
+  end
+
+  local s = asn1_macro.ASN1_STRING_get0_data(asn1)
+  s = ffi_str(s)
+  -- V_ASN1_UTCTIME           190303223958Z
+  -- V_ASN1_GENERALIZEDTIME 21190822162753Z
+  local yyoffset = 2
+  local year
+  -- # define V_ASN1_GENERALIZEDTIME          24
+  if C.ASN1_STRING_type(asn1) == 24 then
+    yyoffset = 4
+    year = tonumber(s:sub(1, yyoffset))
+  else
+    year = tonumber(s:sub(1, yyoffset))
+    year = year + (year < 50 and 2000 or 1900)
+  end
+  local month = tonumber(s:sub(yyoffset+1, yyoffset+2))
+  if month > 12 or month < 1 then
+    return nil, "asn1.asn1_to_unix: bad format " .. s
+  end
+  local day = tonumber(s:sub(yyoffset+3, yyoffset+4))
+  if day > 31 or day < 1 then
+    return nil, "asn1.asn1_to_unix: bad format " .. s
+  end
+  local hour = tonumber(s:sub(yyoffset+5, yyoffset+6))
+  if hour > 23 or hour < 0 then
+    return nil, "asn1.asn1_to_unix: bad format " .. s
+  end
+  local minute = tonumber(s:sub(yyoffset+7, yyoffset+8))
+  if minute > 59 or hour < 0 then
+    return nil, "asn1.asn1_to_unix: bad format " .. s
+  end
+  local second = tonumber(s:sub(yyoffset+9, yyoffset+10))
+  if second > 59 or second < 0 then
+    return nil, "asn1.asn1_to_unix: bad format " .. s
+  end
+
+  local tm
+  tm = (year - 1970) * 365
+  tm = tm + leaps(year - 1) - leaps(1969)
+  tm = (tm + yday(year, month, day)) * 24
+  tm = (tm + hour) * 60
+  tm = (tm + minute) * 60
+  tm = tm + second
+
+  -- offset?
+  local sign = s:sub(yyoffset+11, yyoffset+11)
+  if sign == "+" or sign == "-" then
+    local sgn = sign == "+" and 1 or -1
+    local hh = tonumber(s:sub(yyoffset+12, yyoffset+13) or 'no')
+    local mm = tonumber(s:sub(yyoffset+14, yyoffset+15) or 'no')
+    if not hh or not mm then
+      return nil, "asn1.asn1_to_unix: bad format " .. s
+    end
+    tm = tm + sgn * (hh * 3600 + mm * 60)
+  end
+
+  return tm
+end
+
+return {
+  asn1_to_unix = asn1_to_unix,
+}