Add a built-in SHA256/SHA512 implementation.

This also moves the HMAC-SHA512 implementation to sha2.cpp.

8 files changed, 536 insertions, 76 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index e1542203f8..4e94d47066 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -75,6 +75,7 @@ BITCOIN_CORE_H = \
   rpcserver.h \
   script.h \
   serialize.h \
+  sha2.h \
   sync.h \
   threadsafety.h \
   tinyformat.h \
@@ -152,6 +153,7 @@ libbitcoin_common_a_SOURCES = \
   protocol.cpp \
   rpcprotocol.cpp \
   script.cpp \
+  sha2.cpp \
   sync.cpp \
   util.cpp \
   version.cpp \
diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index 988830260c..93723309af 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -33,6 +33,7 @@ BITCOIN_TESTS =\
   test/compress_tests.cpp \
   test/DoS_tests.cpp \
   test/getarg_tests.cpp \
+  test/hash_tests.cpp \
   test/key_tests.cpp \
   test/main_tests.cpp \
   test/miner_tests.cpp \
@@ -44,6 +45,7 @@ BITCOIN_TESTS =\
   test/script_P2SH_tests.cpp \
   test/script_tests.cpp \
   test/serialize_tests.cpp \
+  test/sha2_tests.cpp \
   test/sigopcount_tests.cpp \
   test/test_bitcoin.cpp \
   test/transaction_tests.cpp \
diff --git a/src/hash.cpp b/src/hash.cpp
index 7b054bd154..bddd8abf38 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -56,44 +56,3 @@ unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char
 
     return h1;
 }
-
-int HMAC_SHA512_Init(HMAC_SHA512_CTX *pctx, const void *pkey, size_t len)
-{
-    unsigned char key[128];
-    if (len <= 128)
-    {
-        memcpy(key, pkey, len);
-        memset(key + len, 0, 128-len);
-    }
-    else
-    {
-        SHA512_CTX ctxKey;
-        SHA512_Init(&ctxKey);
-        SHA512_Update(&ctxKey, pkey, len);
-        SHA512_Final(key, &ctxKey);
-        memset(key + 64, 0, 64);
-    }
-
-    for (int n=0; n<128; n++)
-        key[n] ^= 0x5c;
-    SHA512_Init(&pctx->ctxOuter);
-    SHA512_Update(&pctx->ctxOuter, key, 128);
-
-    for (int n=0; n<128; n++)
-        key[n] ^= 0x5c ^ 0x36;
-    SHA512_Init(&pctx->ctxInner);
-    return SHA512_Update(&pctx->ctxInner, key, 128);
-}
-
-int HMAC_SHA512_Update(HMAC_SHA512_CTX *pctx, const void *pdata, size_t len)
-{
-    return SHA512_Update(&pctx->ctxInner, pdata, len);
-}
-
-int HMAC_SHA512_Final(unsigned char *pmd, HMAC_SHA512_CTX *pctx)
-{
-    unsigned char buf[64];
-    SHA512_Final(buf, &pctx->ctxInner);
-    SHA512_Update(&pctx->ctxOuter, buf, 64);
-    return SHA512_Final(pmd, &pctx->ctxOuter);
-}
diff --git a/src/hash.h b/src/hash.h
index 7dbf1b6448..718b627a78 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -126,14 +126,4 @@ inline uint160 Hash160(const std::vector<unsigned char>& vch)
 
 unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash);
 
-typedef struct
-{
-    SHA512_CTX ctxInner;
-    SHA512_CTX ctxOuter;
-} HMAC_SHA512_CTX;
-
-int HMAC_SHA512_Init(HMAC_SHA512_CTX *pctx, const void *pkey, size_t len);
-int HMAC_SHA512_Update(HMAC_SHA512_CTX *pctx, const void *pdata, size_t len);
-int HMAC_SHA512_Final(unsigned char *pmd, HMAC_SHA512_CTX *pctx);
-
 #endif
diff --git a/src/key.cpp b/src/key.cpp
index 4747beffb4..0685948922 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -4,6 +4,8 @@
 
 #include "key.h"
 
+#include "sha2.h"
+
 #include <openssl/bn.h>
 #include <openssl/ecdsa.h>
 #include <openssl/obj_mac.h>
@@ -510,12 +512,10 @@ void static BIP32Hash(const unsigned char chainCode[32], unsigned int nChild, un
     num[1] = (nChild >> 16) & 0xFF;
     num[2] = (nChild >>  8) & 0xFF;
     num[3] = (nChild >>  0) & 0xFF;
-    HMAC_SHA512_CTX ctx;
-    HMAC_SHA512_Init(&ctx, chainCode, 32);
-    HMAC_SHA512_Update(&ctx, &header, 1);
-    HMAC_SHA512_Update(&ctx, data, 32);
-    HMAC_SHA512_Update(&ctx, num, 4);
-    HMAC_SHA512_Final(output, &ctx);
+    CHMAC_SHA512(chainCode, 32).Write(&header, 1)
+                               .Write(data, 32)
+                               .Write(num, 4)
+                               .Finalize(output);
 }
 
 bool CKey::Derive(CKey& keyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const {
@@ -562,13 +562,10 @@ bool CExtKey::Derive(CExtKey &out, unsigned int nChild) const {
 }
 
 void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) {
-    static const char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'};
-    HMAC_SHA512_CTX ctx;
-    HMAC_SHA512_Init(&ctx, hashkey, sizeof(hashkey));
-    HMAC_SHA512_Update(&ctx, seed, nSeedLen);
+    static const unsigned char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'};
     unsigned char out[64];
     LockObject(out);
-    HMAC_SHA512_Final(out, &ctx);
+    CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(out);
     key.Set(&out[0], &out[32], true);
     memcpy(vchChainCode, &out[32], 32);
     UnlockObject(out);
diff --git a/src/sha2.cpp b/src/sha2.cpp
new file mode 100644
index 0000000000..c9beaf220b
--- /dev/null
+++ b/src/sha2.cpp
@@ -0,0 +1,428 @@
+// Copyright (c) 2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "sha2.h"
+
+#include <string.h>
+
+// Internal implementation code.
+namespace {
+
+/** Read 4 bytes, and interpret them as a 32-bit unsigned big-endian integer. */
+uint32_t inline ReadBE32(const unsigned char *data) {
+    return ((uint32_t)data[0] << 24 | (uint32_t)data[1] << 16 | (uint32_t)data[2] << 8 | (uint32_t)data[3]);
+}
+
+/** Write a 32-bit unsigned big-endian integer. */
+void inline WriteBE32(unsigned char *data, uint32_t x) {
+    data[0] = x >> 24;
+    data[1] = x >> 16;
+    data[2] = x >> 8;
+    data[3] = x;
+}
+
+/** Read 8 bytes, and interpret them as a 64-bit unsigned big-endian integer. */
+uint64_t inline ReadBE64(const unsigned char *data) {
+    return ((uint64_t)data[0] << 56 | (uint64_t)data[1] << 48 | (uint64_t)data[2] << 40 | (uint64_t)data[3] << 32 |
+            (uint64_t)data[4] << 24 | (uint64_t)data[5] << 16 | (uint64_t)data[6] << 8  | (uint64_t)data[7]);
+}
+
+/** Write a 64-bit unsigned big-endian integer. */
+void inline WriteBE64(unsigned char *data, uint64_t x) {
+    data[0] = x >> 56;
+    data[1] = x >> 48;
+    data[2] = x >> 40;
+    data[3] = x >> 32;
+    data[4] = x >> 24;
+    data[5] = x >> 16;
+    data[6] = x >> 8;
+    data[7] = x;
+}
+
+/// Internal SHA-256 implementation.
+namespace sha256 {
+
+uint32_t inline Ch(uint32_t x, uint32_t y, uint32_t z) { return z ^ (x & (y ^ z)); }
+uint32_t inline Maj(uint32_t x, uint32_t y, uint32_t z) { return (x & y) | (z & (x | y)); }
+uint32_t inline Sigma0(uint32_t x) { return (x >> 2 | x << 30) ^ (x >> 13 | x << 19) ^ (x >> 22 | x << 10); }
+uint32_t inline Sigma1(uint32_t x) { return (x >> 6 | x << 26) ^ (x >> 11 | x << 21) ^ (x >> 25 | x << 7); }
+uint32_t inline sigma0(uint32_t x) { return (x >> 7 | x << 25) ^ (x >> 18 | x << 14) ^ (x >> 3); }
+uint32_t inline sigma1(uint32_t x) { return (x >> 17 | x << 15) ^ (x >> 19 | x << 13) ^ (x >> 10); }
+
+/** One round of SHA-256. */
+void inline Round(uint32_t a, uint32_t b, uint32_t c, uint32_t &d,
+                  uint32_t e, uint32_t f, uint32_t g, uint32_t &h,
+                  uint32_t k, uint32_t w) {
+    uint32_t t1 = h + Sigma1(e) + Ch(e, f, g) + k + w;
+    uint32_t t2 = Sigma0(a) + Maj(a, b, c);
+    d += t1;
+    h = t1 + t2;
+}
+
+/** Initialize SHA-256 state. */
+void inline Initialize(uint32_t *s) {
+    s[0] = 0x6a09e667ul;
+    s[1] = 0xbb67ae85ul;
+    s[2] = 0x3c6ef372ul;
+    s[3] = 0xa54ff53aul;
+    s[4] = 0x510e527ful;
+    s[5] = 0x9b05688cul;
+    s[6] = 0x1f83d9abul;
+    s[7] = 0x5be0cd19ul;
+}
+
+/** Perform one SHA-256 transformation, processing a 64-byte chunk. */
+void Transform(uint32_t *s, const unsigned char *chunk) {
+    uint32_t a = s[0], b = s[1], c = s[2], d = s[3], e = s[4], f = s[5], g = s[6], h = s[7];
+    uint32_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;
+
+    Round(a, b, c, d, e, f, g, h, 0x428a2f98,  w0 = ReadBE32(chunk + 0));
+    Round(h, a, b, c, d, e, f, g, 0x71374491,  w1 = ReadBE32(chunk + 4));
+    Round(g, h, a, b, c, d, e, f, 0xb5c0fbcf,  w2 = ReadBE32(chunk + 8));
+    Round(f, g, h, a, b, c, d, e, 0xe9b5dba5,  w3 = ReadBE32(chunk + 12));
+    Round(e, f, g, h, a, b, c, d, 0x3956c25b,  w4 = ReadBE32(chunk + 16));
+    Round(d, e, f, g, h, a, b, c, 0x59f111f1,  w5 = ReadBE32(chunk + 20));
+    Round(c, d, e, f, g, h, a, b, 0x923f82a4,  w6 = ReadBE32(chunk + 24));
+    Round(b, c, d, e, f, g, h, a, 0xab1c5ed5,  w7 = ReadBE32(chunk + 28));
+    Round(a, b, c, d, e, f, g, h, 0xd807aa98,  w8 = ReadBE32(chunk + 32));
+    Round(h, a, b, c, d, e, f, g, 0x12835b01,  w9 = ReadBE32(chunk + 36));
+    Round(g, h, a, b, c, d, e, f, 0x243185be, w10 = ReadBE32(chunk + 40));
+    Round(f, g, h, a, b, c, d, e, 0x550c7dc3, w11 = ReadBE32(chunk + 44));
+    Round(e, f, g, h, a, b, c, d, 0x72be5d74, w12 = ReadBE32(chunk + 48));
+    Round(d, e, f, g, h, a, b, c, 0x80deb1fe, w13 = ReadBE32(chunk + 52));
+    Round(c, d, e, f, g, h, a, b, 0x9bdc06a7, w14 = ReadBE32(chunk + 56));
+    Round(b, c, d, e, f, g, h, a, 0xc19bf174, w15 = ReadBE32(chunk + 60));
+
+    Round(a, b, c, d, e, f, g, h, 0xe49b69c1,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0xefbe4786,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0x0fc19dc6,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0x240ca1cc,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x2de92c6f,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x4a7484aa,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x5cb0a9dc,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x76f988da,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0x983e5152,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0xa831c66d,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0xb00327c8, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0xbf597fc7, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0xc6e00bf3, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0xd5a79147, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0x06ca6351, w14 += sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0x14292967, w15 += sigma1(w13) +  w8 + sigma0( w0));
+
+    Round(a, b, c, d, e, f, g, h, 0x27b70a85,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0x2e1b2138,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0x4d2c6dfc,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0x53380d13,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x650a7354,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x766a0abb,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x81c2c92e,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x92722c85,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0xa2bfe8a1,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0xa81a664b,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0xc24b8b70, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0xc76c51a3, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0xd192e819, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0xd6990624, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0xf40e3585, w14 += sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0x106aa070, w15 += sigma1(w13) +  w8 + sigma0( w0));
+
+    Round(a, b, c, d, e, f, g, h, 0x19a4c116,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0x1e376c08,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0x2748774c,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0x34b0bcb5,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x391c0cb3,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x4ed8aa4a,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x5b9cca4f,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x682e6ff3,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0x748f82ee,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0x78a5636f,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0x84c87814, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0x8cc70208, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0x90befffa, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0xa4506ceb, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0xbef9a3f7, w14  + sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0xc67178f2, w15  + sigma1(w13) +  w8 + sigma0( w0));
+
+    s[0] += a;
+    s[1] += b;
+    s[2] += c;
+    s[3] += d;
+    s[4] += e;
+    s[5] += f;
+    s[6] += g;
+    s[7] += h;
+}
+
+}  // namespace sha256
+
+/// Internal SHA-512 implementation.
+namespace sha512 {
+
+uint64_t inline Ch(uint64_t x, uint64_t y, uint64_t z) { return z ^ (x & (y ^ z)); }
+uint64_t inline Maj(uint64_t x, uint64_t y, uint64_t z) { return (x & y) | (z & (x | y)); }
+uint64_t inline Sigma0(uint64_t x) { return (x >> 28 | x << 36) ^ (x >> 34 | x << 30) ^ (x >> 39 | x << 25); }
+uint64_t inline Sigma1(uint64_t x) { return (x >> 14 | x << 50) ^ (x >> 18 | x << 46) ^ (x >> 41 | x << 23); }
+uint64_t inline sigma0(uint64_t x) { return (x >> 1 | x << 63) ^ (x >> 8 | x << 56) ^ (x >> 7); }
+uint64_t inline sigma1(uint64_t x) { return (x >> 19 | x << 45) ^ (x >> 61 | x << 3) ^ (x >> 6); }
+
+/** One round of SHA-512. */
+void inline Round(uint64_t a, uint64_t b, uint64_t c, uint64_t &d,
+                  uint64_t e, uint64_t f, uint64_t g, uint64_t &h,
+                  uint64_t k, uint64_t w) {
+    uint64_t t1 = h + Sigma1(e) + Ch(e, f, g) + k + w;
+    uint64_t t2 = Sigma0(a) + Maj(a, b, c);
+    d += t1;
+    h = t1 + t2;
+}
+
+/** Initialize SHA-256 state. */
+void inline Initialize(uint64_t *s) {
+    s[0] = 0x6a09e667f3bcc908ull;
+    s[1] = 0xbb67ae8584caa73bull;
+    s[2] = 0x3c6ef372fe94f82bull;
+    s[3] = 0xa54ff53a5f1d36f1ull;
+    s[4] = 0x510e527fade682d1ull;
+    s[5] = 0x9b05688c2b3e6c1full;
+    s[6] = 0x1f83d9abfb41bd6bull;
+    s[7] = 0x5be0cd19137e2179ull;
+}
+
+/** Perform one SHA-512 transformation, processing a 128-byte chunk. */
+void Transform(uint64_t *s, const unsigned char *chunk) {
+    uint64_t a = s[0], b = s[1], c = s[2], d = s[3], e = s[4], f = s[5], g = s[6], h = s[7];
+    uint64_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;
+
+    Round(a, b, c, d, e, f, g, h, 0x428a2f98d728ae22ull,  w0 = ReadBE64(chunk + 0));
+    Round(h, a, b, c, d, e, f, g, 0x7137449123ef65cdull,  w1 = ReadBE64(chunk + 8));
+    Round(g, h, a, b, c, d, e, f, 0xb5c0fbcfec4d3b2full,  w2 = ReadBE64(chunk + 16));
+    Round(f, g, h, a, b, c, d, e, 0xe9b5dba58189dbbcull,  w3 = ReadBE64(chunk + 24));
+    Round(e, f, g, h, a, b, c, d, 0x3956c25bf348b538ull,  w4 = ReadBE64(chunk + 32));
+    Round(d, e, f, g, h, a, b, c, 0x59f111f1b605d019ull,  w5 = ReadBE64(chunk + 40));
+    Round(c, d, e, f, g, h, a, b, 0x923f82a4af194f9bull,  w6 = ReadBE64(chunk + 48));
+    Round(b, c, d, e, f, g, h, a, 0xab1c5ed5da6d8118ull,  w7 = ReadBE64(chunk + 56));
+    Round(a, b, c, d, e, f, g, h, 0xd807aa98a3030242ull,  w8 = ReadBE64(chunk + 64));
+    Round(h, a, b, c, d, e, f, g, 0x12835b0145706fbeull,  w9 = ReadBE64(chunk + 72));
+    Round(g, h, a, b, c, d, e, f, 0x243185be4ee4b28cull, w10 = ReadBE64(chunk + 80));
+    Round(f, g, h, a, b, c, d, e, 0x550c7dc3d5ffb4e2ull, w11 = ReadBE64(chunk + 88));
+    Round(e, f, g, h, a, b, c, d, 0x72be5d74f27b896full, w12 = ReadBE64(chunk + 96));
+    Round(d, e, f, g, h, a, b, c, 0x80deb1fe3b1696b1ull, w13 = ReadBE64(chunk + 104));
+    Round(c, d, e, f, g, h, a, b, 0x9bdc06a725c71235ull, w14 = ReadBE64(chunk + 112));
+    Round(b, c, d, e, f, g, h, a, 0xc19bf174cf692694ull, w15 = ReadBE64(chunk + 120));
+
+    Round(a, b, c, d, e, f, g, h, 0xe49b69c19ef14ad2ull,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0xefbe4786384f25e3ull,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0x0fc19dc68b8cd5b5ull,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0x240ca1cc77ac9c65ull,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x2de92c6f592b0275ull,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x4a7484aa6ea6e483ull,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x5cb0a9dcbd41fbd4ull,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x76f988da831153b5ull,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0x983e5152ee66dfabull,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0xa831c66d2db43210ull,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0xb00327c898fb213full, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0xbf597fc7beef0ee4ull, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0xc6e00bf33da88fc2ull, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0xd5a79147930aa725ull, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0x06ca6351e003826full, w14 += sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0x142929670a0e6e70ull, w15 += sigma1(w13) +  w8 + sigma0( w0));
+
+    Round(a, b, c, d, e, f, g, h, 0x27b70a8546d22ffcull,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0x2e1b21385c26c926ull,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0x4d2c6dfc5ac42aedull,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0x53380d139d95b3dfull,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x650a73548baf63deull,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x766a0abb3c77b2a8ull,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x81c2c92e47edaee6ull,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x92722c851482353bull,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0xa2bfe8a14cf10364ull,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0xa81a664bbc423001ull,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0xc24b8b70d0f89791ull, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0xc76c51a30654be30ull, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0xd192e819d6ef5218ull, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0xd69906245565a910ull, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0xf40e35855771202aull, w14 += sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0x106aa07032bbd1b8ull, w15 += sigma1(w13) +  w8 + sigma0( w0));
+
+    Round(a, b, c, d, e, f, g, h, 0x19a4c116b8d2d0c8ull,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0x1e376c085141ab53ull,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0x2748774cdf8eeb99ull,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0x34b0bcb5e19b48a8ull,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x391c0cb3c5c95a63ull,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x4ed8aa4ae3418acbull,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x5b9cca4f7763e373ull,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x682e6ff3d6b2b8a3ull,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0x748f82ee5defb2fcull,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0x78a5636f43172f60ull,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0x84c87814a1f0ab72ull, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0x8cc702081a6439ecull, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0x90befffa23631e28ull, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0xa4506cebde82bde9ull, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0xbef9a3f7b2c67915ull, w14 += sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0xc67178f2e372532bull, w15 += sigma1(w13) +  w8 + sigma0( w0));
+
+    Round(a, b, c, d, e, f, g, h, 0xca273eceea26619cull,  w0 += sigma1(w14) +  w9 + sigma0( w1));
+    Round(h, a, b, c, d, e, f, g, 0xd186b8c721c0c207ull,  w1 += sigma1(w15) + w10 + sigma0( w2));
+    Round(g, h, a, b, c, d, e, f, 0xeada7dd6cde0eb1eull,  w2 += sigma1( w0) + w11 + sigma0( w3));
+    Round(f, g, h, a, b, c, d, e, 0xf57d4f7fee6ed178ull,  w3 += sigma1( w1) + w12 + sigma0( w4));
+    Round(e, f, g, h, a, b, c, d, 0x06f067aa72176fbaull,  w4 += sigma1( w2) + w13 + sigma0( w5));
+    Round(d, e, f, g, h, a, b, c, 0x0a637dc5a2c898a6ull,  w5 += sigma1( w3) + w14 + sigma0( w6));
+    Round(c, d, e, f, g, h, a, b, 0x113f9804bef90daeull,  w6 += sigma1( w4) + w15 + sigma0( w7));
+    Round(b, c, d, e, f, g, h, a, 0x1b710b35131c471bull,  w7 += sigma1( w5) +  w0 + sigma0( w8));
+    Round(a, b, c, d, e, f, g, h, 0x28db77f523047d84ull,  w8 += sigma1( w6) +  w1 + sigma0( w9));
+    Round(h, a, b, c, d, e, f, g, 0x32caab7b40c72493ull,  w9 += sigma1( w7) +  w2 + sigma0(w10));
+    Round(g, h, a, b, c, d, e, f, 0x3c9ebe0a15c9bebcull, w10 += sigma1( w8) +  w3 + sigma0(w11));
+    Round(f, g, h, a, b, c, d, e, 0x431d67c49c100d4cull, w11 += sigma1( w9) +  w4 + sigma0(w12));
+    Round(e, f, g, h, a, b, c, d, 0x4cc5d4becb3e42b6ull, w12 += sigma1(w10) +  w5 + sigma0(w13));
+    Round(d, e, f, g, h, a, b, c, 0x597f299cfc657e2aull, w13 += sigma1(w11) +  w6 + sigma0(w14));
+    Round(c, d, e, f, g, h, a, b, 0x5fcb6fab3ad6faecull, w14 += sigma1(w12) +  w7 + sigma0(w15));
+    Round(b, c, d, e, f, g, h, a, 0x6c44198c4a475817ull, w15 += sigma1(w13) +  w8 + sigma0( w0));
+
+    s[0] += a;
+    s[1] += b;
+    s[2] += c;
+    s[3] += d;
+    s[4] += e;
+    s[5] += f;
+    s[6] += g;
+    s[7] += h;
+}
+
+}  // namespace sha512
+
+}  // namespace
+
+
+////// SHA-256
+
+CSHA256::CSHA256() : bytes(0) {
+    sha256::Initialize(s);
+}
+
+CSHA256& CSHA256::Write(const unsigned char *data, size_t len) {
+    const unsigned char *end = data + len;
+    size_t bufsize = bytes % 64;
+    if (bufsize && bufsize + len >= 64) {
+        // Fill the buffer, and process it.
+        memcpy(buf + bufsize, data, 64 - bufsize);
+        bytes += 64 - bufsize;
+        data += 64 - bufsize;
+        sha256::Transform(s, buf);
+        bufsize = 0;
+    }
+    while (end >= data + 64) {
+        // Process full chunks directly from the source.
+        sha256::Transform(s, data);
+        bytes += 64;
+        data += 64;
+    }
+    if (end > data) {
+        // Fill the buffer with what remains.
+        memcpy(buf + bufsize, data, end - data);
+        bytes += end - data;
+    }
+    return *this;
+}
+
+void CSHA256::Finalize(unsigned char *hash) {
+    static const unsigned char pad[64] = {0x80};
+    unsigned char sizedesc[8];
+    WriteBE64(sizedesc, bytes << 3);
+    Write(pad, 1 + ((119 - (bytes % 64)) % 64));
+    Write(sizedesc, 8);
+    WriteBE32(hash, s[0]);
+    WriteBE32(hash+4, s[1]);
+    WriteBE32(hash+8, s[2]);
+    WriteBE32(hash+12, s[3]);
+    WriteBE32(hash+16, s[4]);
+    WriteBE32(hash+20, s[5]);
+    WriteBE32(hash+24, s[6]);
+    WriteBE32(hash+28, s[7]);
+}
+
+CSHA256& CSHA256::Reset() {
+    bytes = 0;
+    sha256::Initialize(s);
+    return *this;
+}
+
+////// SHA-512
+
+CSHA512::CSHA512() : bytes(0) {
+    sha512::Initialize(s);
+}
+
+CSHA512& CSHA512::Write(const unsigned char *data, size_t len) {
+    const unsigned char *end = data + len;
+    size_t bufsize = bytes % 128;
+    if (bufsize && bufsize + len >= 128) {
+        // Fill the buffer, and process it.
+        memcpy(buf + bufsize, data, 128 - bufsize);
+        bytes += 128 - bufsize;
+        data += 128 - bufsize;
+        sha512::Transform(s, buf);
+        bufsize = 0;
+    }
+    while (end >= data + 128) {
+        // Process full chunks directly from the source.
+        sha512::Transform(s, data);
+        data += 128;
+        bytes += 128;
+    }
+    if (end > data) {
+        // Fill the buffer with what remains.
+        memcpy(buf + bufsize, data, end - data);
+        bytes += end - data;
+    }
+    return *this;
+}
+
+void CSHA512::Finalize(unsigned char *hash) {
+    static const unsigned char pad[128] = {0x80};
+    unsigned char sizedesc[16] = {0x00};
+    WriteBE64(sizedesc+8, bytes << 3);
+    Write(pad, 1 + ((239 - (bytes % 128)) % 128));
+    Write(sizedesc, 16);
+    WriteBE64(hash, s[0]);
+    WriteBE64(hash+8, s[1]);
+    WriteBE64(hash+16, s[2]);
+    WriteBE64(hash+24, s[3]);
+    WriteBE64(hash+32, s[4]);
+    WriteBE64(hash+40, s[5]);
+    WriteBE64(hash+48, s[6]);
+    WriteBE64(hash+56, s[7]);
+}
+
+CSHA512& CSHA512::Reset() {
+    bytes = 0;
+    sha512::Initialize(s);
+    return *this;
+}
+
+////// HMAC-SHA-512
+
+CHMAC_SHA512::CHMAC_SHA512(const unsigned char *key, size_t keylen) {
+    unsigned char rkey[128];
+    if (keylen <= 128) {
+        memcpy(rkey, key, keylen);
+        memset(rkey + keylen, 0, 128 - keylen);
+    } else {
+        CSHA512().Write(key, keylen).Finalize(rkey);
+        memset(rkey + 64, 0, 64);
+    }
+
+    for (int n=0; n<128; n++)
+        rkey[n] ^= 0x5c;
+    outer.Write(rkey, 128);
+
+    for (int n=0; n<128; n++)
+        rkey[n] ^= 0x5c ^ 0x36;
+    inner.Write(rkey, 128);
+}
+
+void CHMAC_SHA512::Finalize(unsigned char *hash) {
+    unsigned char temp[64];
+    inner.Finalize(temp);
+    outer.Write(temp, 64).Finalize(hash);
+}
diff --git a/src/sha2.h b/src/sha2.h
new file mode 100644
index 0000000000..001bfc647c
--- /dev/null
+++ b/src/sha2.h
@@ -0,0 +1,54 @@
+// Copyright (c) 2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_SHA2_H
+#define BITCOIN_SHA2_H
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/** A hasher class for SHA-256. */
+class CSHA256 {
+private:
+    uint32_t s[8];
+    unsigned char buf[64];
+    size_t bytes;
+
+public:
+    CSHA256();
+    CSHA256& Write(const unsigned char *data, size_t len);
+    void Finalize(unsigned char *hash);
+    CSHA256& Reset();
+};
+
+/** A hasher class for SHA-512. */
+class CSHA512 {
+private:
+    uint64_t s[8];
+    unsigned char buf[128];
+    size_t bytes;
+
+public:
+    CSHA512();
+    CSHA512& Write(const unsigned char *data, size_t len);
+    void Finalize(unsigned char *hash);
+    CSHA512& Reset();
+};
+
+/** A hasher class for HMAC-SHA-512. */
+class CHMAC_SHA512 {
+private:
+    CSHA512 outer;
+    CSHA512 inner;
+
+public:
+    CHMAC_SHA512(const unsigned char *key, size_t keylen);
+    CHMAC_SHA512& Write(const unsigned char *data, size_t len) {
+        inner.Write(data, len);
+        return *this;
+    }
+    void Finalize(unsigned char *hash);
+};
+
+#endif
diff --git a/src/test/hmac_tests.cpp b/src/test/sha2_tests.cpp
index 780ce480ce..516b942ad3 100644
--- a/src/test/hmac_tests.cpp
+++ b/src/test/sha2_tests.cpp
@@ -1,15 +1,49 @@
-// Copyright (c) 2013 The Bitcoin Core developers
+// Copyright (c) 2014 The Bitcoin Core developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "hash.h"
+#include "sha2.h"
 #include "util.h"
 
+#include <vector>
+
 #include <boost/test/unit_test.hpp>
 
-using namespace std;
+BOOST_AUTO_TEST_SUITE(sha2_tests)
+
+void SHA256TestVector(const std::string &in, const std::string &out) {
+    std::vector<unsigned char> hash;
+    hash.resize(32);
+    CSHA256().Write((unsigned char*)&in[0], in.size()).Finalize(&hash[0]);
+    BOOST_CHECK_EQUAL(HexStr(hash), out);
+}
+
+void SHA512TestVector(const std::string &in, const std::string &out) {
+    std::vector<unsigned char> hash;
+    hash.resize(64);
+    CSHA512().Write((unsigned char*)&in[0], in.size()).Finalize(&hash[0]);
+    BOOST_CHECK_EQUAL(HexStr(hash), out);
+}
 
-BOOST_AUTO_TEST_SUITE(hmac_tests)
+BOOST_AUTO_TEST_CASE(sha256_testvectors) {
+    SHA256TestVector("", "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
+    SHA256TestVector("abc", "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad");
+    SHA256TestVector("message digest", "f7846f55cf23e14eebeab5b4e1550cad5b509e3348fbc4efa3a1413d393cb650");
+    SHA256TestVector("secure hash algorithm", "f30ceb2bb2829e79e4ca9753d35a8ecc00262d164cc077080295381cbd643f0d");
+    SHA256TestVector("SHA256 is considered to be safe", "6819d915c73f4d1e77e4e1b52d1fa0f9cf9beaead3939f15874bd988e2a23630");
+    SHA256TestVector("abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", "248d6a61d20638b8e5c026930c3e6039a33ce45964ff2167f6ecedd419db06c1");
+    SHA256TestVector("For this sample, this 63-byte string will be used as input data", "f08a78cbbaee082b052ae0708f32fa1e50c5c421aa772ba5dbb406a2ea6be342");
+    SHA256TestVector("This is exactly 64 bytes long, not counting the terminating byte", "ab64eff7e88e2e46165e29f2bce41826bd4c7b3552f6b382a9e7d3af47c245f8");
+    SHA256TestVector("As Bitcoin relies on 80 byte header hashes, we want to have an example for that.", "7406e8de7d6e4fffc573daef05aefb8806e7790f55eab5576f31349743cca743");
+}
+
+BOOST_AUTO_TEST_CASE(sha512_testvectors) {
+    SHA512TestVector("abc", "ddaf35a193617abacc417349ae20413112e6fa4e89a97ea20a9eeee64b55d39a2192992a274fc1a836ba3c23a3feebbd454d4423643ce80e2a9ac94fa54ca49f");
+    SHA512TestVector("abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", "204a8fc6dda82f0a0ced7beb8e08a41657c16ef468b228a8279be331a703c33596fd15c13b1b07f9aa1d3bea57789ca031ad85c7a71dd70354ec631238ca3445");
+    SHA512TestVector("abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu", "8e959b75dae313da8cf4f72814fc143f8f7779c6eb9f7fa17299aeadb6889018501d289e4900f7e4331b99dec4b5433ac7d329eeb6dd26545e96e55b874be909");
+    SHA512TestVector(std::string(1000000, 'a'), "e718483d0ce769644e2e42c7bc15b4638e1f98b13b2044285632a803afa973ebde0ff244877ea60a4cb0432ce577c31beb009c5c2c49aa2e4eadb217ad8cc09b");
+    SHA512TestVector("", "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e");
+}
 
 typedef struct {
     const char *pszKey;
@@ -111,18 +145,12 @@ BOOST_AUTO_TEST_CASE(hmacsha512_testvectors)
 {
     for (unsigned int n=0; n<sizeof(vtest)/sizeof(vtest[0]); n++)
     {
-        vector<unsigned char> vchKey  = ParseHex(vtest[n].pszKey);
-        vector<unsigned char> vchData = ParseHex(vtest[n].pszData);
-        vector<unsigned char> vchMAC  = ParseHex(vtest[n].pszMAC);
+        std::vector<unsigned char> vchKey  = ParseHex(vtest[n].pszKey);
+        std::vector<unsigned char> vchData = ParseHex(vtest[n].pszData);
+        std::vector<unsigned char> vchMAC  = ParseHex(vtest[n].pszMAC);
         unsigned char vchTemp[64];
-
-        HMAC_SHA512_CTX ctx;
-        HMAC_SHA512_Init(&ctx, &vchKey[0], vchKey.size());
-        HMAC_SHA512_Update(&ctx, &vchData[0], vchData.size());
-        HMAC_SHA512_Final(&vchTemp[0], &ctx);
-
+        CHMAC_SHA512(&vchKey[0], vchKey.size()).Write(&vchData[0], vchData.size()).Finalize(&vchTemp[0]);
         BOOST_CHECK(memcmp(&vchTemp[0], &vchMAC[0], 64) == 0);
-
     }
 }