Merge #19296: tests: Add fuzzing harness for AES{CBC,}256{Encrypt,Decrypt}, poly1305_auth, CHKDF_HMAC_SHA256_L32, ChaCha20 and ChaCha20Poly1305AEAD

cca7c577d5d80293cb12de1048f3edd680ac4fad tests: Add fuzzing harness for ChaCha20Poly1305AEAD (practicalswift)
2fc4e5916c1c35902a32830c3f199a308a66bea0 tests: Add fuzzing harness for ChaCha20 (practicalswift)
e9e8aac029acffb5e4cc5c2556f23cdfdcf9bb09 tests: Add fuzzing harness for CHKDF_HMAC_SHA256_L32 (practicalswift)
ec86ca1aaae388cefa2da9904785cee2d550b3d1 tests: Add fuzzing harness for poly1305_auth(...) (practicalswift)
4cee53bba722a480ccd6472d2ffe9b0001394dd9 tests: Add fuzzing harness for AES256CBCEncrypt/AES256CBCDecrypt (practicalswift)
9352c3232594f953d2db11c1e140be3f7f9fbae4 tests: Add fuzzing harness for AES256Encrypt/AES256Decrypt (practicalswift)

Pull request description:

  Add fuzzing harness for `AES{CBC,}256{Encrypt,Decrypt}`, `poly1305_auth`, `CHKDF_HMAC_SHA256_L32`, `ChaCha20` and `ChaCha20Poly1305AEAD`.

  See [`doc/fuzzing.md`](https://github.com/bitcoin/bitcoin/blob/master/doc/fuzzing.md) for information on how to fuzz Bitcoin Core. Don't forget to contribute any coverage increasing inputs you find to the [Bitcoin Core fuzzing corpus repo](https://github.com/bitcoin-core/qa-assets).

  Happy fuzzing :)

ACKs for top commit:
  laanwj:
    ACK cca7c577d5d80293cb12de1048f3edd680ac4fad

Tree-SHA512: cff9acefe370c12a3663aa55145371df835479c6ab8f6d81bbf84e0f81a9d6b0d94e45ec545f9dd5e1702744eaa7947a1f4ffed0171f446fc080369161afd740

6 files changed, 233 insertions, 0 deletions

diff --git a/src/test/fuzz/crypto_aes256.cpp b/src/test/fuzz/crypto_aes256.cpp
new file mode 100644
index 0000000000..ae14073c96
--- /dev/null
+++ b/src/test/fuzz/crypto_aes256.cpp
@@ -0,0 +1,30 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/aes.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cassert>
+#include <cstdint>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+    const std::vector<uint8_t> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, AES256_KEYSIZE);
+
+    AES256Encrypt encrypt{key.data()};
+    AES256Decrypt decrypt{key.data()};
+
+    while (fuzzed_data_provider.ConsumeBool()) {
+        const std::vector<uint8_t> plaintext = ConsumeFixedLengthByteVector(fuzzed_data_provider, AES_BLOCKSIZE);
+        std::vector<uint8_t> ciphertext(AES_BLOCKSIZE);
+        encrypt.Encrypt(ciphertext.data(), plaintext.data());
+        std::vector<uint8_t> decrypted_plaintext(AES_BLOCKSIZE);
+        decrypt.Decrypt(decrypted_plaintext.data(), ciphertext.data());
+        assert(decrypted_plaintext == plaintext);
+    }
+}
diff --git a/src/test/fuzz/crypto_aes256cbc.cpp b/src/test/fuzz/crypto_aes256cbc.cpp
new file mode 100644
index 0000000000..52983c7e79
--- /dev/null
+++ b/src/test/fuzz/crypto_aes256cbc.cpp
@@ -0,0 +1,34 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/aes.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cassert>
+#include <cstdint>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+    const std::vector<uint8_t> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, AES256_KEYSIZE);
+    const std::vector<uint8_t> iv = ConsumeFixedLengthByteVector(fuzzed_data_provider, AES_BLOCKSIZE);
+    const bool pad = fuzzed_data_provider.ConsumeBool();
+
+    AES256CBCEncrypt encrypt{key.data(), iv.data(), pad};
+    AES256CBCDecrypt decrypt{key.data(), iv.data(), pad};
+
+    while (fuzzed_data_provider.ConsumeBool()) {
+        const std::vector<uint8_t> plaintext = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+        std::vector<uint8_t> ciphertext(plaintext.size() + AES_BLOCKSIZE);
+        const int encrypt_ret = encrypt.Encrypt(plaintext.data(), plaintext.size(), ciphertext.data());
+        ciphertext.resize(encrypt_ret);
+        std::vector<uint8_t> decrypted_plaintext(ciphertext.size());
+        const int decrypt_ret = decrypt.Decrypt(ciphertext.data(), ciphertext.size(), decrypted_plaintext.data());
+        decrypted_plaintext.resize(decrypt_ret);
+        assert(decrypted_plaintext == plaintext || (!pad && plaintext.size() % AES_BLOCKSIZE != 0 && encrypt_ret == 0 && decrypt_ret == 0));
+    }
+}
diff --git a/src/test/fuzz/crypto_chacha20.cpp b/src/test/fuzz/crypto_chacha20.cpp
new file mode 100644
index 0000000000..b7438d312d
--- /dev/null
+++ b/src/test/fuzz/crypto_chacha20.cpp
@@ -0,0 +1,50 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/chacha20.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+
+    ChaCha20 chacha20;
+    if (fuzzed_data_provider.ConsumeBool()) {
+        const std::vector<unsigned char> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, fuzzed_data_provider.ConsumeIntegralInRange<size_t>(16, 32));
+        chacha20 = ChaCha20{key.data(), key.size()};
+    }
+    while (fuzzed_data_provider.ConsumeBool()) {
+        switch (fuzzed_data_provider.ConsumeIntegralInRange(0, 4)) {
+        case 0: {
+            const std::vector<unsigned char> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, fuzzed_data_provider.ConsumeIntegralInRange<size_t>(16, 32));
+            chacha20.SetKey(key.data(), key.size());
+            break;
+        }
+        case 1: {
+            chacha20.SetIV(fuzzed_data_provider.ConsumeIntegral<uint64_t>());
+            break;
+        }
+        case 2: {
+            chacha20.Seek(fuzzed_data_provider.ConsumeIntegral<uint64_t>());
+            break;
+        }
+        case 3: {
+            std::vector<uint8_t> output(fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096));
+            chacha20.Keystream(output.data(), output.size());
+            break;
+        }
+        case 4: {
+            std::vector<uint8_t> output(fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096));
+            const std::vector<uint8_t> input = ConsumeFixedLengthByteVector(fuzzed_data_provider, output.size());
+            chacha20.Crypt(input.data(), output.data(), input.size());
+            break;
+        }
+        }
+    }
+}
diff --git a/src/test/fuzz/crypto_chacha20_poly1305_aead.cpp b/src/test/fuzz/crypto_chacha20_poly1305_aead.cpp
new file mode 100644
index 0000000000..48e4263f27
--- /dev/null
+++ b/src/test/fuzz/crypto_chacha20_poly1305_aead.cpp
@@ -0,0 +1,72 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/chacha_poly_aead.h>
+#include <crypto/poly1305.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cassert>
+#include <cstdint>
+#include <limits>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+
+    const std::vector<uint8_t> k1 = ConsumeFixedLengthByteVector(fuzzed_data_provider, CHACHA20_POLY1305_AEAD_KEY_LEN);
+    const std::vector<uint8_t> k2 = ConsumeFixedLengthByteVector(fuzzed_data_provider, CHACHA20_POLY1305_AEAD_KEY_LEN);
+
+    ChaCha20Poly1305AEAD aead(k1.data(), k1.size(), k2.data(), k2.size());
+    uint64_t seqnr_payload = 0;
+    uint64_t seqnr_aad = 0;
+    int aad_pos = 0;
+    size_t buffer_size = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096);
+    std::vector<uint8_t> in(buffer_size + CHACHA20_POLY1305_AEAD_AAD_LEN + POLY1305_TAGLEN, 0);
+    std::vector<uint8_t> out(buffer_size + CHACHA20_POLY1305_AEAD_AAD_LEN + POLY1305_TAGLEN, 0);
+    bool is_encrypt = fuzzed_data_provider.ConsumeBool();
+    while (fuzzed_data_provider.ConsumeBool()) {
+        switch (fuzzed_data_provider.ConsumeIntegralInRange<int>(0, 6)) {
+        case 0: {
+            buffer_size = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(64, 4096);
+            in = std::vector<uint8_t>(buffer_size + CHACHA20_POLY1305_AEAD_AAD_LEN + POLY1305_TAGLEN, 0);
+            out = std::vector<uint8_t>(buffer_size + CHACHA20_POLY1305_AEAD_AAD_LEN + POLY1305_TAGLEN, 0);
+            break;
+        }
+        case 1: {
+            (void)aead.Crypt(seqnr_payload, seqnr_aad, aad_pos, out.data(), out.size(), in.data(), buffer_size, is_encrypt);
+            break;
+        }
+        case 2: {
+            uint32_t len = 0;
+            const bool ok = aead.GetLength(&len, seqnr_aad, aad_pos, in.data());
+            assert(ok);
+            break;
+        }
+        case 3: {
+            seqnr_payload += 1;
+            aad_pos += CHACHA20_POLY1305_AEAD_AAD_LEN;
+            if (aad_pos + CHACHA20_POLY1305_AEAD_AAD_LEN > CHACHA20_ROUND_OUTPUT) {
+                aad_pos = 0;
+                seqnr_aad += 1;
+            }
+            break;
+        }
+        case 4: {
+            seqnr_payload = fuzzed_data_provider.ConsumeIntegral<int>();
+            break;
+        }
+        case 5: {
+            seqnr_aad = fuzzed_data_provider.ConsumeIntegral<int>();
+            break;
+        }
+        case 6: {
+            is_encrypt = fuzzed_data_provider.ConsumeBool();
+            break;
+        }
+        }
+    }
+}
diff --git a/src/test/fuzz/crypto_hkdf_hmac_sha256_l32.cpp b/src/test/fuzz/crypto_hkdf_hmac_sha256_l32.cpp
new file mode 100644
index 0000000000..e0a4e90c10
--- /dev/null
+++ b/src/test/fuzz/crypto_hkdf_hmac_sha256_l32.cpp
@@ -0,0 +1,25 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/hkdf_sha256_32.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+
+    const std::vector<uint8_t> initial_key_material = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+
+    CHKDF_HMAC_SHA256_L32 hkdf_hmac_sha256_l32(initial_key_material.data(), initial_key_material.size(), fuzzed_data_provider.ConsumeRandomLengthString(1024));
+    while (fuzzed_data_provider.ConsumeBool()) {
+        std::vector<uint8_t> out(32);
+        hkdf_hmac_sha256_l32.Expand32(fuzzed_data_provider.ConsumeRandomLengthString(128), out.data());
+    }
+}
diff --git a/src/test/fuzz/crypto_poly1305.cpp b/src/test/fuzz/crypto_poly1305.cpp
new file mode 100644
index 0000000000..5681e6a693
--- /dev/null
+++ b/src/test/fuzz/crypto_poly1305.cpp
@@ -0,0 +1,22 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/poly1305.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+
+    const std::vector<uint8_t> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, POLY1305_KEYLEN);
+    const std::vector<uint8_t> in = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+
+    std::vector<uint8_t> tag_out(POLY1305_TAGLEN);
+    poly1305_auth(tag_out.data(), in.data(), in.size(), key.data());
+}