Merge #13438: Improve coverage of SHA256 SelfTest code

1e1eb6367f67dcf968bb62993b98b5873b926fc0 Improve coverage of SHA256 SelfTest code (Pieter Wuille)

Pull request description:

  The existing SelfTest code does not cover the specialized double-SHA256-for-64-byte-inputs transforms added in #13191. Fix this.

Tree-SHA512: 593c7ee5dc9e77fc4c89e0a7753a63529b0d3d32ddbc015ae3895b52be77bee8a80bf16b754b30a22c01625a68db83fb77fa945a543143542bebb5b0f017ec5b

src/crypto/sha256.cpp

@@ -446,38 +446,90 @@ void TransformD64Wrapper(unsigned char* out, const unsigned char* in)
     WriteBE32(out + 28, s[7]);
 }
 
-bool SelfTest(TransformType tr) {
-    static const unsigned char in1[65] = {0, 0x80};
-    static const unsigned char in2[129] = {
-        0,
-        32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 
-        32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 
-        0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0
-    };
-    static const uint32_t init[8] = {0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, 0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul};
-    static const uint32_t out1[8] = {0xe3b0c442ul, 0x98fc1c14ul, 0x9afbf4c8ul, 0x996fb924ul, 0x27ae41e4ul, 0x649b934cul, 0xa495991bul, 0x7852b855ul};
-    static const uint32_t out2[8] = {0xce4153b0ul, 0x147c2a86ul, 0x3ed4298eul, 0xe0676bc8ul, 0x79fc77a1ul, 0x2abe1f49ul, 0xb2b055dful, 0x1069523eul};
-    uint32_t buf[8];
-    memcpy(buf, init, sizeof(buf));
-    // Process nothing, and check we remain in the initial state.
-    tr(buf, nullptr, 0);
-    if (memcmp(buf, init, sizeof(buf))) return false;
-    // Process the padded empty string (unaligned)
-    tr(buf, in1 + 1, 1);
-    if (memcmp(buf, out1, sizeof(buf))) return false;
-    // Process 64 spaces (unaligned)
-    memcpy(buf, init, sizeof(buf));
-    tr(buf, in2 + 1, 2);
-    if (memcmp(buf, out2, sizeof(buf))) return false;
-    return true;
-}
-
 TransformType Transform = sha256::Transform;
 TransformD64Type TransformD64 = sha256::TransformD64;
 TransformD64Type TransformD64_4way = nullptr;
 TransformD64Type TransformD64_8way = nullptr;
 
+bool SelfTest() {
+    // Input state (equal to the initial SHA256 state)
+    static const uint32_t init[8] = {
+        0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, 0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul
+    };
+    // Some random input data to test with
+    static const unsigned char data[641] = "-" // Intentionally not aligned
+        "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do "
+        "eiusmod tempor incididunt ut labore et dolore magna aliqua. Et m"
+        "olestie ac feugiat sed lectus vestibulum mattis ullamcorper. Mor"
+        "bi blandit cursus risus at ultrices mi tempus imperdiet nulla. N"
+        "unc congue nisi vita suscipit tellus mauris. Imperdiet proin fer"
+        "mentum leo vel orci. Massa tempor nec feugiat nisl pretium fusce"
+        " id velit. Telus in metus vulputate eu scelerisque felis. Mi tem"
+        "pus imperdiet nulla malesuada pellentesque. Tristique magna sit.";
+    // Expected output state for hashing the i*64 first input bytes above (excluding SHA256 padding).
+    static const uint32_t result[9][8] = {
+        {0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, 0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul},
+        {0x91f8ec6bul, 0x4da10fe3ul, 0x1c9c292cul, 0x45e18185ul, 0x435cc111ul, 0x3ca26f09ul, 0xeb954caeul, 0x402a7069ul},
+        {0xcabea5acul, 0x374fb97cul, 0x182ad996ul, 0x7bd69cbful, 0x450ff900ul, 0xc1d2be8aul, 0x6a41d505ul, 0xe6212dc3ul},
+        {0xbcff09d6ul, 0x3e76f36eul, 0x3ecb2501ul, 0x78866e97ul, 0xe1c1e2fdul, 0x32f4eafful, 0x8aa6c4e5ul, 0xdfc024bcul},
+        {0xa08c5d94ul, 0x0a862f93ul, 0x6b7f2f40ul, 0x8f9fae76ul, 0x6d40439ful, 0x79dcee0cul, 0x3e39ff3aul, 0xdc3bdbb1ul},
+        {0x216a0895ul, 0x9f1a3662ul, 0xe99946f9ul, 0x87ba4364ul, 0x0fb5db2cul, 0x12bed3d3ul, 0x6689c0c7ul, 0x292f1b04ul},
+        {0xca3067f8ul, 0xbc8c2656ul, 0x37cb7e0dul, 0x9b6b8b0ful, 0x46dc380bul, 0xf1287f57ul, 0xc42e4b23ul, 0x3fefe94dul},
+        {0x3e4c4039ul, 0xbb6fca8cul, 0x6f27d2f7ul, 0x301e44a4ul, 0x8352ba14ul, 0x5769ce37ul, 0x48a1155ful, 0xc0e1c4c6ul},
+        {0xfe2fa9ddul, 0x69d0862bul, 0x1ae0db23ul, 0x471f9244ul, 0xf55c0145ul, 0xc30f9c3bul, 0x40a84ea0ul, 0x5b8a266cul},
+    };
+    // Expected output for each of the individual 8 64-byte messages under full double SHA256 (including padding).
+    static const unsigned char result_d64[256] = {
+        0x09, 0x3a, 0xc4, 0xd0, 0x0f, 0xf7, 0x57, 0xe1, 0x72, 0x85, 0x79, 0x42, 0xfe, 0xe7, 0xe0, 0xa0,
+        0xfc, 0x52, 0xd7, 0xdb, 0x07, 0x63, 0x45, 0xfb, 0x53, 0x14, 0x7d, 0x17, 0x22, 0x86, 0xf0, 0x52,
+        0x48, 0xb6, 0x11, 0x9e, 0x6e, 0x48, 0x81, 0x6d, 0xcc, 0x57, 0x1f, 0xb2, 0x97, 0xa8, 0xd5, 0x25,
+        0x9b, 0x82, 0xaa, 0x89, 0xe2, 0xfd, 0x2d, 0x56, 0xe8, 0x28, 0x83, 0x0b, 0xe2, 0xfa, 0x53, 0xb7,
+        0xd6, 0x6b, 0x07, 0x85, 0x83, 0xb0, 0x10, 0xa2, 0xf5, 0x51, 0x3c, 0xf9, 0x60, 0x03, 0xab, 0x45,
+        0x6c, 0x15, 0x6e, 0xef, 0xb5, 0xac, 0x3e, 0x6c, 0xdf, 0xb4, 0x92, 0x22, 0x2d, 0xce, 0xbf, 0x3e,
+        0xe9, 0xe5, 0xf6, 0x29, 0x0e, 0x01, 0x4f, 0xd2, 0xd4, 0x45, 0x65, 0xb3, 0xbb, 0xf2, 0x4c, 0x16,
+        0x37, 0x50, 0x3c, 0x6e, 0x49, 0x8c, 0x5a, 0x89, 0x2b, 0x1b, 0xab, 0xc4, 0x37, 0xd1, 0x46, 0xe9,
+        0x3d, 0x0e, 0x85, 0xa2, 0x50, 0x73, 0xa1, 0x5e, 0x54, 0x37, 0xd7, 0x94, 0x17, 0x56, 0xc2, 0xd8,
+        0xe5, 0x9f, 0xed, 0x4e, 0xae, 0x15, 0x42, 0x06, 0x0d, 0x74, 0x74, 0x5e, 0x24, 0x30, 0xce, 0xd1,
+        0x9e, 0x50, 0xa3, 0x9a, 0xb8, 0xf0, 0x4a, 0x57, 0x69, 0x78, 0x67, 0x12, 0x84, 0x58, 0xbe, 0xc7,
+        0x36, 0xaa, 0xee, 0x7c, 0x64, 0xa3, 0x76, 0xec, 0xff, 0x55, 0x41, 0x00, 0x2a, 0x44, 0x68, 0x4d,
+        0xb6, 0x53, 0x9e, 0x1c, 0x95, 0xb7, 0xca, 0xdc, 0x7f, 0x7d, 0x74, 0x27, 0x5c, 0x8e, 0xa6, 0x84,
+        0xb5, 0xac, 0x87, 0xa9, 0xf3, 0xff, 0x75, 0xf2, 0x34, 0xcd, 0x1a, 0x3b, 0x82, 0x2c, 0x2b, 0x4e,
+        0x6a, 0x46, 0x30, 0xa6, 0x89, 0x86, 0x23, 0xac, 0xf8, 0xa5, 0x15, 0xe9, 0x0a, 0xaa, 0x1e, 0x9a,
+        0xd7, 0x93, 0x6b, 0x28, 0xe4, 0x3b, 0xfd, 0x59, 0xc6, 0xed, 0x7c, 0x5f, 0xa5, 0x41, 0xcb, 0x51
+    };
+
+
+    // Test Transform() for 0 through 8 transformations.
+    for (size_t i = 0; i <= 8; ++i) {
+        uint32_t state[8];
+        std::copy(init, init + 8, state);
+        Transform(state, data + 1, i);
+        if (!std::equal(state, state + 8, result[i])) return false;
+    }
+
+    // Test TransformD64
+    unsigned char out[32];
+    TransformD64(out, data + 1);
+    if (!std::equal(out, out + 32, result_d64)) return false;
+
+    // Test TransformD64_4way, if available.
+    if (TransformD64_4way) {
+        unsigned char out[128];
+        TransformD64_4way(out, data + 1);
+        if (!std::equal(out, out + 128, result_d64)) return false;
+    }
+
+    // Test TransformD64_8way, if available.
+    if (TransformD64_8way) {
+        unsigned char out[256];
+        TransformD64_8way(out, data + 1);
+        if (!std::equal(out, out + 256, result_d64)) return false;
+    }
+
+    return true;
+}
+
+
 #if defined(USE_ASM) && (defined(__x86_64__) || defined(__amd64__))
 // We can't use cpuid.h's __get_cpuid as it does not support subleafs.
 void inline cpuid(uint32_t leaf, uint32_t subleaf, uint32_t& a, uint32_t& b, uint32_t& c, uint32_t& d)
@@ -513,7 +565,7 @@ std::string SHA256AutoDetect()
     }
 #endif
 
-    assert(SelfTest(Transform));
+    assert(SelfTest());
     return ret;
 }