init: v1.0.0

grand/drng/drng.go

@@ -0,0 +1,100 @@
+// package drng implements the SM3Rng and SM4Rng which specified in GM/T 0115.
+//
+// ctrrng and hashrng implements the low-level Drng interface.
+// Combine entropy(pool) and xxxrng we got the Drng as a ReadWriter.
+// The Read method generates random bits, and the Write method
+// add outter entropy into the Drng.
+//
+// Use drng.SM3Rng as an ordinary io.Reader to generate random bits.
+// If necessary, it could add extra entropy into the Drng.
+// For example, add user's scratch points on mobile, get random bits
+// from the cryptography server, etc..
+package drng
+
+import (
+	"io"
+	"sync"
+
+	"xdx.jelly/xgcl/grand/drng/ctrrng"
+	"xdx.jelly/xgcl/grand/drng/entropy"
+	"xdx.jelly/xgcl/grand/drng/hashrng"
+	"xdx.jelly/xgcl/grand/drng/internal"
+	"xdx.jelly/xgcl/sm"
+)
+
+// PERSONALIZATIONSTRING = "粤信签协同签名软件Android客户端密码模块YXQXTQM-Y"
+var PERSONALIZATIONSTRING = []byte("xdx")
+
+// SM3Rng implements the io.ReadWriter interface.
+//
+// SM3Rng.Read reads random bytes from the DRNG.
+// SM3rng.Write add extra entropy to the DRNG.
+var SM3Rng io.ReadWriter
+var SM4Rng io.ReadWriter
+
+func init() {
+	raw, _ := hashrng.NewHashDrng(sm.SM3, hashrng.Config(internal.SecureLevel2))
+	rng, _ := raw.Instantiate(PERSONALIZATIONSTRING, internal.Nonce(), entropy.GetEntropyPool())
+	SM3Rng = &DrngUtil{
+		Drng:         rng,
+		ReseedSource: entropy.GetEntropyPool(),
+	}
+
+	raw, _ = ctrrng.NewCtrDrng(ctrrng.SM4BlockNewer{}, ctrrng.Config(internal.SecureLevel2))
+	rng, _ = raw.Instantiate(PERSONALIZATIONSTRING, internal.Nonce(), entropy.GetEntropyPool())
+	SM4Rng = &DrngUtil{
+		Drng:         rng,
+		ReseedSource: entropy.GetEntropyPool(),
+	}
+}
+
+// DrngUtil implements the io.Reader interface
+type DrngUtil struct {
+	mu sync.Mutex
+	internal.Drng
+	ReseedSource io.Reader // 重播种熵源
+
+	additionalInput io.Reader // TODO: 额外输入, 可为空
+}
+
+// Write implements io.ReadWriter.
+// The returns can be ignored.
+func (du *DrngUtil) Write(p []byte) (n int, err error) {
+	du.mu.Lock()
+	defer du.mu.Unlock()
+
+	du.Drng.Reseed(p, nil)
+	return len(p), nil
+}
+
+// Read implements io.Reader
+func (du *DrngUtil) Read(p []byte) (n int, err error) {
+	du.mu.Lock()
+	defer du.mu.Unlock()
+
+	outlen := du.OutLen()
+	for len(p) > 0 {
+		generateLen := len(p)
+		if generateLen > outlen {
+			generateLen = outlen
+		}
+		err := du.Generate(p[:generateLen], nil)
+		if err != nil {
+			// 需要重播种
+			config := du.Config()
+			entropyInput := make([]byte, config.MinEntropy)
+			n, err := du.ReseedSource.Read(entropyInput)
+			if err != nil {
+				return n, err
+			}
+			du.Drng.Reseed(entropyInput[:n], nil)
+			err = du.Generate(p[:generateLen], nil)
+			if err != nil {
+				return n, err
+			}
+		}
+		n += generateLen
+		p = p[generateLen:]
+	}
+	return n, nil
+}