1 files changed, 128 insertions, 0 deletions
diff --git a/src/cmd/internal/notsha256/sha256block.go b/src/cmd/internal/notsha256/sha256block.go
new file mode 100644
index 00000000000..57cdf2efd55
--- /dev/null
+++ b/src/cmd/internal/notsha256/sha256block.go
@@ -0,0 +1,128 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// SHA256 block step.
+// In its own file so that a faster assembly or C version
+// can be substituted easily.
+
+package notsha256
+
+import "math/bits"
+
+var _K = []uint32{
+	0x428a2f98,
+	0x71374491,
+	0xb5c0fbcf,
+	0xe9b5dba5,
+	0x3956c25b,
+	0x59f111f1,
+	0x923f82a4,
+	0xab1c5ed5,
+	0xd807aa98,
+	0x12835b01,
+	0x243185be,
+	0x550c7dc3,
+	0x72be5d74,
+	0x80deb1fe,
+	0x9bdc06a7,
+	0xc19bf174,
+	0xe49b69c1,
+	0xefbe4786,
+	0x0fc19dc6,
+	0x240ca1cc,
+	0x2de92c6f,
+	0x4a7484aa,
+	0x5cb0a9dc,
+	0x76f988da,
+	0x983e5152,
+	0xa831c66d,
+	0xb00327c8,
+	0xbf597fc7,
+	0xc6e00bf3,
+	0xd5a79147,
+	0x06ca6351,
+	0x14292967,
+	0x27b70a85,
+	0x2e1b2138,
+	0x4d2c6dfc,
+	0x53380d13,
+	0x650a7354,
+	0x766a0abb,
+	0x81c2c92e,
+	0x92722c85,
+	0xa2bfe8a1,
+	0xa81a664b,
+	0xc24b8b70,
+	0xc76c51a3,
+	0xd192e819,
+	0xd6990624,
+	0xf40e3585,
+	0x106aa070,
+	0x19a4c116,
+	0x1e376c08,
+	0x2748774c,
+	0x34b0bcb5,
+	0x391c0cb3,
+	0x4ed8aa4a,
+	0x5b9cca4f,
+	0x682e6ff3,
+	0x748f82ee,
+	0x78a5636f,
+	0x84c87814,
+	0x8cc70208,
+	0x90befffa,
+	0xa4506ceb,
+	0xbef9a3f7,
+	0xc67178f2,
+}
+
+func blockGeneric(dig *digest, p []byte) {
+	var w [64]uint32
+	h0, h1, h2, h3, h4, h5, h6, h7 := dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7]
+	for len(p) >= chunk {
+		// Can interlace the computation of w with the
+		// rounds below if needed for speed.
+		for i := 0; i < 16; i++ {
+			j := i * 4
+			w[i] = uint32(p[j])<<24 | uint32(p[j+1])<<16 | uint32(p[j+2])<<8 | uint32(p[j+3])
+		}
+		for i := 16; i < 64; i++ {
+			v1 := w[i-2]
+			t1 := (bits.RotateLeft32(v1, -17)) ^ (bits.RotateLeft32(v1, -19)) ^ (v1 >> 10)
+			v2 := w[i-15]
+			t2 := (bits.RotateLeft32(v2, -7)) ^ (bits.RotateLeft32(v2, -18)) ^ (v2 >> 3)
+			w[i] = t1 + w[i-7] + t2 + w[i-16]
+		}
+
+		a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7
+
+		for i := 0; i < 64; i++ {
+			t1 := h + ((bits.RotateLeft32(e, -6)) ^ (bits.RotateLeft32(e, -11)) ^ (bits.RotateLeft32(e, -25))) + ((e & f) ^ (^e & g)) + _K[i] + w[i]
+
+			t2 := ((bits.RotateLeft32(a, -2)) ^ (bits.RotateLeft32(a, -13)) ^ (bits.RotateLeft32(a, -22))) + ((a & b) ^ (a & c) ^ (b & c))
+
+			h = g
+			g = f
+			f = e
+			e = d + t1
+			d = c
+			c = b
+			b = a
+			a = t1 + t2
+		}
+
+		h0 += a
+		h1 += b
+		h2 += c
+		h3 += d
+		h4 += e
+		h5 += f
+		h6 += g
+		h7 += h
+
+		p = p[chunk:]
+	}
+
+	dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7] = h0, h1, h2, h3, h4, h5, h6, h7
+}