Merge GH #1743 Avoid memset/memcpy in library code

20 files changed, 84 insertions, 58 deletions

diff --git a/src/cli/tls_client.cpp b/src/cli/tls_client.cpp
index 7834d9328..dfe874313 100644
--- a/src/cli/tls_client.cpp
+++ b/src/cli/tls_client.cpp
@@ -280,7 +280,7 @@ class TLS_Client final : public Command, public Botan::TLS::Callbacks
       int connect_to_host(const std::string& host, uint16_t port, bool tcp)
          {
          addrinfo hints;
-         std::memset(&hints, 0, sizeof(hints));
+         Botan::clear_mem(&hints, 1);
          hints.ai_family = AF_UNSPEC;
          hints.ai_socktype = tcp ? SOCK_STREAM : SOCK_DGRAM;
          addrinfo* res, *rp = nullptr;
diff --git a/src/cli/tls_server.cpp b/src/cli/tls_server.cpp
index 0fd075741..c8e6c58f3 100644
--- a/src/cli/tls_server.cpp
+++ b/src/cli/tls_server.cpp
@@ -213,7 +213,7 @@ class TLS_Server final : public Command, public Botan::TLS::Callbacks
             }
 
          sockaddr_in socket_info;
-         ::memset(&socket_info, 0, sizeof(socket_info));
+         Botan::clear_mem(&socket_info, 1);
          socket_info.sin_family = AF_INET;
          socket_info.sin_port = htons(port);
 
diff --git a/src/lib/hash/streebog/streebog.cpp b/src/lib/hash/streebog/streebog.cpp
index cd67256cb..8bb56ccc9 100644
--- a/src/lib/hash/streebog/streebog.cpp
+++ b/src/lib/hash/streebog/streebog.cpp
@@ -35,9 +35,10 @@ static inline void addm(const uint8_t* m, uint64_t* h)
       }
    }
 
-inline void lps(uint64_t* block)
+inline void lps(uint64_t block[8])
    {
    uint8_t r[64];
+   // FIXME
    std::memcpy(r, block, 64);
 
    for(int i = 0; i < 8; ++i)
@@ -171,6 +172,7 @@ void Streebog::final_result(uint8_t output[])
    compress(m_buffer.data(), true);
 
    compress(reinterpret_cast<const uint8_t*>(m_S.data()), true);
+   // FIXME
    std::memcpy(output, &m_h[8 - output_length() / 8], output_length());
    clear();
    }
diff --git a/src/lib/prov/bearssl/bearssl_hash.cpp b/src/lib/prov/bearssl/bearssl_hash.cpp
index 564935624..2b837bcf5 100644
--- a/src/lib/prov/bearssl/bearssl_hash.cpp
+++ b/src/lib/prov/bearssl/bearssl_hash.cpp
@@ -37,7 +37,7 @@ class BearSSL_HashFunction final : public HashFunction
       std::unique_ptr<HashFunction> copy_state() const override
          {
          std::unique_ptr<BearSSL_HashFunction> copy(new BearSSL_HashFunction(m_ctx.vtable, m_name));
-         memcpy(&copy->m_ctx, &m_ctx, sizeof(m_ctx));
+         std::memcpy(&copy->m_ctx, &m_ctx, sizeof(m_ctx));
          return std::move(copy);
          }
 
diff --git a/src/lib/prov/commoncrypto/commoncrypto_mode.cpp b/src/lib/prov/commoncrypto/commoncrypto_mode.cpp
index a3a27637a..cb30b6802 100644
--- a/src/lib/prov/commoncrypto/commoncrypto_mode.cpp
+++ b/src/lib/prov/commoncrypto/commoncrypto_mode.cpp
@@ -111,7 +111,7 @@ size_t CommonCrypto_Cipher_Mode::process(uint8_t msg[], size_t msg_len)
       {
       throw CommonCrypto_Error("CCCryptorUpdate", status);
       }
-   memcpy(msg, out.data(), outl);
+   copy_mem(msg, out.data(), outl);
 
    return outl;
    }
@@ -143,7 +143,7 @@ void CommonCrypto_Cipher_Mode::finish(secure_vector<uint8_t>& buffer,
       {
       buffer.resize(new_len);
       }
-   memcpy(buffer.data() - offset + written, out.data(), outl);
+   copy_mem(buffer.data() - offset + written, out.data(), outl);
    written += outl;
    }
 
diff --git a/src/lib/prov/commoncrypto/commoncrypto_utils.cpp b/src/lib/prov/commoncrypto/commoncrypto_utils.cpp
index 9ec9c30ee..97da49496 100644
--- a/src/lib/prov/commoncrypto/commoncrypto_utils.cpp
+++ b/src/lib/prov/commoncrypto/commoncrypto_utils.cpp
@@ -178,7 +178,7 @@ void commoncrypto_adjust_key_size(const uint8_t key[], size_t length,
       full_key.resize(length * repeat);
       for(int i=0; i<repeat; i++)
          {
-         memcpy(full_key.data() + i * length, key, length);
+         copy_mem(full_key.data() + i * length, key, length);
          }
       }
    else if(opts.algo == kCCAlgorithm3DES && length == 16)
diff --git a/src/lib/prov/openssl/openssl_mode.cpp b/src/lib/prov/openssl/openssl_mode.cpp
index 5636d008f..d1983949d 100644
--- a/src/lib/prov/openssl/openssl_mode.cpp
+++ b/src/lib/prov/openssl/openssl_mode.cpp
@@ -117,7 +117,7 @@ size_t OpenSSL_Cipher_Mode::process(uint8_t msg[], size_t msg_len)
 
    if(!EVP_CipherUpdate(m_cipher, out.data(), &outl, msg, msg_len))
       throw OpenSSL_Error("EVP_CipherUpdate");
-   memcpy(msg, out.data(), outl);
+   copy_mem(msg, out.data(), outl);
    return outl;
    }
 
@@ -137,7 +137,7 @@ void OpenSSL_Cipher_Mode::finish(secure_vector<uint8_t>& buffer,
 
    if(!EVP_CipherFinal_ex(m_cipher, out.data(), &outl))
       throw OpenSSL_Error("EVP_CipherFinal_ex");
-   memcpy(buf + written, out.data(), outl);
+   copy_mem(buf + written, out.data(), outl);
    written += outl;
    buffer.resize(offset + written);
    }
diff --git a/src/lib/prov/openssl/openssl_rsa.cpp b/src/lib/prov/openssl/openssl_rsa.cpp
index 98c0734a8..4e9068ce4 100644
--- a/src/lib/prov/openssl/openssl_rsa.cpp
+++ b/src/lib/prov/openssl/openssl_rsa.cpp
@@ -302,7 +302,7 @@ make_openssl_rsa_private_key(RandomNumberGenerator& rng, size_t rsa_bits)
       throw OpenSSL_Error("i2d_RSAPrivateKey");
 
    const secure_vector<uint8_t> keydata(der, der + bytes);
-   memset(der, 0, bytes);
+   secure_scrub_memory(der, bytes);
    std::free(der);
    return std::unique_ptr<Botan::RSA_PrivateKey>
       (new RSA_PrivateKey(AlgorithmIdentifier(), keydata));
diff --git a/src/lib/prov/pkcs11/p11_mechanism.h b/src/lib/prov/pkcs11/p11_mechanism.h
index 035d1e69a..8947372fd 100644
--- a/src/lib/prov/pkcs11/p11_mechanism.h
+++ b/src/lib/prov/pkcs11/p11_mechanism.h
@@ -92,12 +92,12 @@ class MechanismWrapper final
          return m_padding_size;
          }
 
-      /// Holds the mechanism parameters for OEAP, PSS and ECDH
+      /// Holds the mechanism parameters for OAEP, PSS and ECDH
       union MechanismParameters
          {
          MechanismParameters()
             {
-            std::memset(this, 0, sizeof(MechanismParameters));
+            clear_mem(this, 1);
             }
 
          RsaPkcsOaepParams oaep_params;
diff --git a/src/lib/prov/tpm/tpm.cpp b/src/lib/prov/tpm/tpm.cpp
index 4847b0df6..5516d41a0 100644
--- a/src/lib/prov/tpm/tpm.cpp
+++ b/src/lib/prov/tpm/tpm.cpp
@@ -113,7 +113,7 @@ TSS_UUID to_tss_uuid(const UUID& uuid)
    static_assert(sizeof(TSS_UUID) == 16, "Expected size of packed UUID");
 
    TSS_UUID tss_uuid;
-   std::memcpy(&tss_uuid, uuid.binary_value().data(), 16);
+   typecast_copy(tss_uuid, uuid.binary_value().data());
    return tss_uuid;
    }
 
@@ -122,7 +122,7 @@ UUID from_tss_uuid(const TSS_UUID& tss_uuid)
    static_assert(sizeof(TSS_UUID) == 16, "Expected size of packed UUID");
 
    std::vector<uint8_t> mem(16);
-   std::memcpy(mem.data(), &tss_uuid, 16);
+   typecast_copy(mem.data(), tss_uuid);
    UUID uuid(std::move(mem));
    return uuid;
    }
@@ -191,7 +191,7 @@ void TPM_Context::gen_random(uint8_t out[], size_t out_len)
    {
    BYTE* mem;
    TSPI_CHECK_SUCCESS(::Tspi_TPM_GetRandom(m_tpm, out_len, &mem));
-   std::memcpy(out, mem, out_len);
+   copy_mem(out, reinterpret_cast<const uint8_t*>(mem), out_len);
    TSPI_CHECK_SUCCESS(::Tspi_Context_FreeMemory(m_ctx, mem));
    }
 
diff --git a/src/lib/pubkey/ed25519/ed25519.cpp b/src/lib/pubkey/ed25519/ed25519.cpp
index d959df709..b75028041 100644
--- a/src/lib/pubkey/ed25519/ed25519.cpp
+++ b/src/lib/pubkey/ed25519/ed25519.cpp
@@ -29,8 +29,8 @@ void ed25519_gen_keypair(uint8_t* pk, uint8_t* sk, const uint8_t seed[32])
    ge_scalarmult_base(pk, az);
 
    // todo copy_mem
-   memmove(sk, seed, 32);
-   memmove(sk + 32, pk, 32);
+   copy_mem(sk, seed, 32);
+   copy_mem(sk + 32, pk, 32);
    }
 
 void ed25519_sign(uint8_t sig[64],
diff --git a/src/lib/pubkey/ed25519/ed25519_fe.h b/src/lib/pubkey/ed25519/ed25519_fe.h
index af92af46a..bcdc36a5e 100644
--- a/src/lib/pubkey/ed25519/ed25519_fe.h
+++ b/src/lib/pubkey/ed25519/ed25519_fe.h
@@ -30,16 +30,16 @@ class FE_25519
       FE_25519(int init = 0)
          {
          if(init != 0 && init != 1)
-            { throw Invalid_Argument("Invalid FE_25519 initial value"); }
-         memset(m_fe, 0, 10 * sizeof(int32_t));
+            throw Invalid_Argument("Invalid FE_25519 initial value");
+         clear_mem(m_fe, 10);
          m_fe[0] = init;
          }
 
       FE_25519(std::initializer_list<int32_t> x)
          {
          if(x.size() != 10)
-            { throw Invalid_Argument("Invalid FE_25519 initializer list"); }
-         memcpy(m_fe, x.begin(), 10 * sizeof(int32_t));
+            throw Invalid_Argument("Invalid FE_25519 initializer list");
+         copy_mem(m_fe, x.begin(), 10);
          }
 
       FE_25519(int64_t h0, int64_t h1, int64_t h2, int64_t h3, int64_t h4,
diff --git a/src/lib/stream/chacha/chacha_avx2/chacha_avx2.cpp b/src/lib/stream/chacha/chacha_avx2/chacha_avx2.cpp
index e9c3aeb75..8cd2eca7f 100644
--- a/src/lib/stream/chacha/chacha_avx2/chacha_avx2.cpp
+++ b/src/lib/stream/chacha/chacha_avx2/chacha_avx2.cpp
@@ -183,7 +183,6 @@ void ChaCha::chacha_avx2_x8(uint8_t output[64*8], uint32_t state[16], size_t rou
    SIMD_8x32::transpose(R08, R09, R10, R11);
    SIMD_8x32::transpose(R12, R13, R14, R15);
 
-   memset(output, 0, 16*32);
    __m256i* output_mm = reinterpret_cast<__m256i*>(output);
 
    _mm256_storeu_si256(output_mm     , _mm256_permute2x128_si256(R00.handle(), R04.handle(), 0 + (2 << 4)));
diff --git a/src/lib/utils/loadstor.h b/src/lib/utils/loadstor.h
index 2fb1543b0..579d05deb 100644
--- a/src/lib/utils/loadstor.h
+++ b/src/lib/utils/loadstor.h
@@ -140,7 +140,7 @@ inline uint16_t load_be<uint16_t>(const uint8_t in[], size_t off)
 
 #if defined(BOTAN_ENDIAN_N2B)
    uint16_t x;
-   std::memcpy(&x, in, sizeof(x));
+   typecast_copy(x, in);
    return BOTAN_ENDIAN_N2B(x);
 #else
    return make_uint16(in[0], in[1]);
@@ -160,7 +160,7 @@ inline uint16_t load_le<uint16_t>(const uint8_t in[], size_t off)
 
 #if defined(BOTAN_ENDIAN_N2L)
    uint16_t x;
-   std::memcpy(&x, in, sizeof(x));
+   typecast_copy(x, in);
    return BOTAN_ENDIAN_N2L(x);
 #else
    return make_uint16(in[1], in[0]);
@@ -179,7 +179,7 @@ inline uint32_t load_be<uint32_t>(const uint8_t in[], size_t off)
    in += off * sizeof(uint32_t);
 #if defined(BOTAN_ENDIAN_N2B)
    uint32_t x;
-   std::memcpy(&x, in, sizeof(x));
+   typecast_copy(x, in);
    return BOTAN_ENDIAN_N2B(x);
 #else
    return make_uint32(in[0], in[1], in[2], in[3]);
@@ -198,7 +198,7 @@ inline uint32_t load_le<uint32_t>(const uint8_t in[], size_t off)
    in += off * sizeof(uint32_t);
 #if defined(BOTAN_ENDIAN_N2L)
    uint32_t x;
-   std::memcpy(&x, in, sizeof(x));
+   typecast_copy(x, in);
    return BOTAN_ENDIAN_N2L(x);
 #else
    return make_uint32(in[3], in[2], in[1], in[0]);
@@ -217,7 +217,7 @@ inline uint64_t load_be<uint64_t>(const uint8_t in[], size_t off)
    in += off * sizeof(uint64_t);
 #if defined(BOTAN_ENDIAN_N2B)
    uint64_t x;
-   std::memcpy(&x, in, sizeof(x));
+   typecast_copy(x, in);
    return BOTAN_ENDIAN_N2B(x);
 #else
    return make_uint64(in[0], in[1], in[2], in[3],
@@ -237,7 +237,7 @@ inline uint64_t load_le<uint64_t>(const uint8_t in[], size_t off)
    in += off * sizeof(uint64_t);
 #if defined(BOTAN_ENDIAN_N2L)
    uint64_t x;
-   std::memcpy(&x, in, sizeof(x));
+   typecast_copy(x, in);
    return BOTAN_ENDIAN_N2L(x);
 #else
    return make_uint64(in[7], in[6], in[5], in[4],
@@ -317,9 +317,11 @@ inline void load_le(T out[],
    if(count > 0)
       {
 #if defined(BOTAN_TARGET_CPU_IS_LITTLE_ENDIAN)
-      std::memcpy(out, in, sizeof(T)*count);
+      typecast_copy(out, in, count);
+
 #elif defined(BOTAN_TARGET_CPU_IS_BIG_ENDIAN)
-      std::memcpy(out, in, sizeof(T)*count);
+      typecast_copy(out, in, count);
+
       const size_t blocks = count - (count % 4);
       const size_t left = count - blocks;
 
@@ -407,10 +409,10 @@ inline void load_be(T out[],
    if(count > 0)
       {
 #if defined(BOTAN_TARGET_CPU_IS_BIG_ENDIAN)
-      std::memcpy(out, in, sizeof(T)*count);
+      typecast_copy(out, in, count);
 
 #elif defined(BOTAN_TARGET_CPU_IS_LITTLE_ENDIAN)
-      std::memcpy(out, in, sizeof(T)*count);
+      typecast_copy(out, in, count);
       const size_t blocks = count - (count % 4);
       const size_t left = count - blocks;
 
@@ -435,7 +437,7 @@ inline void store_be(uint16_t in, uint8_t out[2])
    {
 #if defined(BOTAN_ENDIAN_N2B)
    uint16_t o = BOTAN_ENDIAN_N2B(in);
-   std::memcpy(out, &o, sizeof(o));
+   typecast_copy(out, o);
 #else
    out[0] = get_byte(0, in);
    out[1] = get_byte(1, in);
@@ -451,7 +453,7 @@ inline void store_le(uint16_t in, uint8_t out[2])
    {
 #if defined(BOTAN_ENDIAN_N2L)
    uint16_t o = BOTAN_ENDIAN_N2L(in);
-   std::memcpy(out, &o, sizeof(o));
+   typecast_copy(out, o);
 #else
    out[0] = get_byte(1, in);
    out[1] = get_byte(0, in);
@@ -467,7 +469,7 @@ inline void store_be(uint32_t in, uint8_t out[4])
    {
 #if defined(BOTAN_ENDIAN_B2N)
    uint32_t o = BOTAN_ENDIAN_B2N(in);
-   std::memcpy(out, &o, sizeof(o));
+   typecast_copy(out, o);
 #else
    out[0] = get_byte(0, in);
    out[1] = get_byte(1, in);
@@ -485,7 +487,7 @@ inline void store_le(uint32_t in, uint8_t out[4])
    {
 #if defined(BOTAN_ENDIAN_L2N)
    uint32_t o = BOTAN_ENDIAN_L2N(in);
-   std::memcpy(out, &o, sizeof(o));
+   typecast_copy(out, o);
 #else
    out[0] = get_byte(3, in);
    out[1] = get_byte(2, in);
@@ -503,7 +505,7 @@ inline void store_be(uint64_t in, uint8_t out[8])
    {
 #if defined(BOTAN_ENDIAN_B2N)
    uint64_t o = BOTAN_ENDIAN_B2N(in);
-   std::memcpy(out, &o, sizeof(o));
+   typecast_copy(out, o);
 #else
    out[0] = get_byte(0, in);
    out[1] = get_byte(1, in);
@@ -525,7 +527,7 @@ inline void store_le(uint64_t in, uint8_t out[8])
    {
 #if defined(BOTAN_ENDIAN_L2N)
    uint64_t o = BOTAN_ENDIAN_L2N(in);
-   std::memcpy(out, &o, sizeof(o));
+   typecast_copy(out, o);
 #else
    out[0] = get_byte(7, in);
    out[1] = get_byte(6, in);
diff --git a/src/lib/utils/mem_ops.h b/src/lib/utils/mem_ops.h
index c59c02d5a..f0599c8b2 100644
--- a/src/lib/utils/mem_ops.h
+++ b/src/lib/utils/mem_ops.h
@@ -113,6 +113,21 @@ template<typename T> inline void copy_mem(T* out, const T* in, size_t n)
       }
    }
 
+template<typename T> inline void typecast_copy(uint8_t out[], T in)
+   {
+   std::memcpy(out, &in, sizeof(T));
+   }
+
+template<typename T> inline void typecast_copy(T& out, const uint8_t in[])
+   {
+   std::memcpy(&out, in, sizeof(T));
+   }
+
+template<typename T> inline void typecast_copy(T out[], const uint8_t in[], size_t N)
+   {
+   std::memcpy(out, in, sizeof(T)*N);
+   }
+
 /**
 * Set memory to a fixed value
 * @param ptr a pointer to an array
@@ -178,15 +193,16 @@ inline void xor_buf(uint8_t out[],
    while(length >= 16)
       {
       uint64_t x0, x1, y0, y1;
-      std::memcpy(&x0, in, 8);
-      std::memcpy(&x1, in + 8, 8);
-      std::memcpy(&y0, out, 8);
-      std::memcpy(&y1, out + 8, 8);
+
+      typecast_copy(x0, in);
+      typecast_copy(x1, in + 8);
+      typecast_copy(y0, out);
+      typecast_copy(y1, out + 8);
 
       y0 ^= x0;
       y1 ^= x1;
-      std::memcpy(out, &y0, 8);
-      std::memcpy(out + 8, &y1, 8);
+      typecast_copy(out, y0);
+      typecast_copy(out + 8, y1);
       out += 16; in += 16; length -= 16;
       }
 
@@ -214,15 +230,15 @@ inline void xor_buf(uint8_t out[],
    while(length >= 16)
       {
       uint64_t x0, x1, y0, y1;
-      std::memcpy(&x0, in, 8);
-      std::memcpy(&x1, in + 8, 8);
-      std::memcpy(&y0, in2, 8);
-      std::memcpy(&y1, in2 + 8, 8);
+      typecast_copy(x0, in);
+      typecast_copy(x1, in + 8);
+      typecast_copy(y0, in2);
+      typecast_copy(y1, in2 + 8);
 
       x0 ^= y0;
       x1 ^= y1;
-      std::memcpy(out, &x0, 8);
-      std::memcpy(out + 8, &x1, 8);
+      typecast_copy(out, x0);
+      typecast_copy(out + 8, x1);
       out += 16; in += 16; in2 += 16; length -= 16;
       }
 
diff --git a/src/lib/utils/socket/socket.cpp b/src/lib/utils/socket/socket.cpp
index 1caeb2413..39ffc7951 100644
--- a/src/lib/utils/socket/socket.cpp
+++ b/src/lib/utils/socket/socket.cpp
@@ -207,7 +207,7 @@ class BSD_Socket final : public OS::Socket
          m_socket = invalid_socket();
 
          addrinfo hints;
-         ::memset(&hints, 0, sizeof(addrinfo));
+         clear_mem(&hints, 1);
          hints.ai_family = AF_UNSPEC;
          hints.ai_socktype = SOCK_STREAM;
          addrinfo* res;
diff --git a/src/tests/test_block.cpp b/src/tests/test_block.cpp
index a53ff2633..ceda8ca07 100644
--- a/src/tests/test_block.cpp
+++ b/src/tests/test_block.cpp
@@ -137,7 +137,7 @@ class Block_Cipher_Tests final : public Text_Based_Test
             // Now test misaligned buffers
             const size_t blocks = input.size() / cipher->block_size();
             buf.resize(input.size() + 1);
-            std::memcpy(buf.data() + 1, input.data(), input.size());
+            Botan::copy_mem(buf.data() + 1, input.data(), input.size());
 
             for(size_t i = 0; i != iterations; ++i)
                {
@@ -149,7 +149,7 @@ class Block_Cipher_Tests final : public Text_Based_Test
                            expected.data(), expected.size());
 
             // always decrypt expected ciphertext vs what we produced above
-            std::memcpy(buf.data() + 1, expected.data(), expected.size());
+            Botan::copy_mem(buf.data() + 1, expected.data(), expected.size());
 
             for(size_t i = 0; i != iterations; ++i)
                {
diff --git a/src/tests/test_rng.h b/src/tests/test_rng.h
index 37501da2e..822536971 100644
--- a/src/tests/test_rng.h
+++ b/src/tests/test_rng.h
@@ -212,7 +212,12 @@ class Request_Counting_RNG final : public Botan::RandomNumberGenerator
 
       void randomize(uint8_t out[], size_t out_len) override
          {
-         std::memset(out, 0x80, out_len);
+         /*
+         The HMAC_DRBG and ChaCha reseed KATs assume this RNG type
+         outputs all 0x80
+         */
+         for(size_t i = 0; i != out_len; ++i)
+            out[i] = 0x80;
          m_randomize_count++;
          }
 
diff --git a/src/tests/test_tls.cpp b/src/tests/test_tls.cpp
index af13a83b8..8a327b652 100644
--- a/src/tests/test_tls.cpp
+++ b/src/tests/test_tls.cpp
@@ -110,7 +110,8 @@ class TLS_CBC_Tests final : public Text_Based_Test
 
             void final_result(uint8_t out[]) override
                {
-               std::memset(out, 0, m_mac_len);
+               for(size_t i = 0; i != m_mac_len; ++i)
+                  out[i] = 0;
                }
 
             Botan::Key_Length_Specification key_spec() const override
@@ -133,12 +134,12 @@ class TLS_CBC_Tests final : public Text_Based_Test
 
             void encrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override
                {
-               std::memmove(out, in, blocks * m_bs);
+               Botan::copy_mem(out, in, blocks * m_bs);
                }
 
             void decrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override
                {
-               std::memmove(out, in, blocks * m_bs);
+               Botan::copy_mem(out, in, blocks * m_bs);
                }
 
             size_t block_size() const override { return m_bs; }
diff --git a/src/tests/test_utils.cpp b/src/tests/test_utils.cpp
index b6eb4bbc7..7bbe3745c 100644
--- a/src/tests/test_utils.cpp
+++ b/src/tests/test_utils.cpp
@@ -843,7 +843,8 @@ class UUID_Tests : public Test
 
                void randomize(uint8_t out[], size_t len) override
                   {
-                  std::memset(out, m_val, len);
+                  for(size_t i = 0; i != len; ++i)
+                     out[i] = m_val;
                   }
 
                std::string name() const override { return "zeros"; }