1 files changed, 90 insertions, 0 deletions
diff --git a/server/resty/openssl/hmac.lua b/server/resty/openssl/hmac.lua
new file mode 100644
index 0000000..fe18d2f
--- /dev/null
+++ b/server/resty/openssl/hmac.lua
@@ -0,0 +1,90 @@
+local ffi = require "ffi"
+local C = ffi.C
+local ffi_gc = ffi.gc
+local ffi_str = ffi.string
+
+require "resty.openssl.include.hmac"
+require "resty.openssl.include.evp.md"
+local ctypes = require "resty.openssl.auxiliary.ctypes"
+local format_error = require("resty.openssl.err").format_error
+local OPENSSL_10 = require("resty.openssl.version").OPENSSL_10
+local OPENSSL_11_OR_LATER = require("resty.openssl.version").OPENSSL_11_OR_LATER
+local OPENSSL_3X = require("resty.openssl.version").OPENSSL_3X
+
+local _M = {}
+local mt = {__index = _M}
+
+local hmac_ctx_ptr_ct = ffi.typeof('HMAC_CTX*')
+
+-- Note: https://www.openssl.org/docs/manmaster/man3/HMAC_Init.html
+-- Replace with EVP_MAC_* functions for OpenSSL 3.0
+
+function _M.new(key, typ)
+  local ctx
+  if OPENSSL_11_OR_LATER then
+    ctx = C.HMAC_CTX_new()
+    ffi_gc(ctx, C.HMAC_CTX_free)
+  elseif OPENSSL_10 then
+    ctx = ffi.new('HMAC_CTX')
+    C.HMAC_CTX_init(ctx)
+    ffi_gc(ctx, C.HMAC_CTX_cleanup)
+  end
+  if ctx == nil then
+    return nil, "hmac.new: failed to create HMAC_CTX"
+  end
+
+  local algo = C.EVP_get_digestbyname(typ or 'sha1')
+  if algo == nil then
+    return nil, string.format("hmac.new: invalid digest type \"%s\"", typ)
+  end
+
+  local code = C.HMAC_Init_ex(ctx, key, #key, algo, nil)
+  if code ~= 1 then
+    return nil, format_error("hmac.new")
+  end
+
+  return setmetatable({
+    ctx = ctx,
+    algo = algo,
+    buf = ctypes.uchar_array(OPENSSL_3X and C.EVP_MD_get_size(algo) or C.EVP_MD_size(algo)),
+  }, mt), nil
+end
+
+function _M.istype(l)
+  return l and l.ctx and ffi.istype(hmac_ctx_ptr_ct, l.ctx)
+end
+
+function _M:update(...)
+  for _, s in ipairs({...}) do
+    if C.HMAC_Update(self.ctx, s, #s) ~= 1 then
+      return false, format_error("hmac:update")
+    end
+  end
+  return true, nil
+end
+
+local result_length = ctypes.ptr_of_uint()
+
+function _M:final(s)
+  if s then
+    if C.HMAC_Update(self.ctx, s, #s) ~= 1 then
+      return false, format_error("hmac:final")
+    end
+  end
+
+  if C.HMAC_Final(self.ctx, self.buf, result_length) ~= 1 then
+    return nil, format_error("hmac:final: HMAC_Final")
+  end
+  return ffi_str(self.buf, result_length[0])
+end
+
+function _M:reset()
+  local code = C.HMAC_Init_ex(self.ctx, nil, 0, nil, nil)
+  if code ~= 1 then
+    return false, format_error("hmac:reset")
+  end
+
+  return true
+end
+
+return _M