diff options
Diffstat (limited to 'src/libs/3rdparty/botan/src/lib/rng/system_rng/system_rng.cpp')
| -rw-r--r-- | src/libs/3rdparty/botan/src/lib/rng/system_rng/system_rng.cpp | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/src/libs/3rdparty/botan/src/lib/rng/system_rng/system_rng.cpp b/src/libs/3rdparty/botan/src/lib/rng/system_rng/system_rng.cpp new file mode 100644 index 0000000000..c3b37ea9cc --- /dev/null +++ b/src/libs/3rdparty/botan/src/lib/rng/system_rng/system_rng.cpp @@ -0,0 +1,231 @@ +/* +* System RNG +* (C) 2014,2015,2017,2018 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/system_rng.h> + +#if defined(BOTAN_TARGET_OS_HAS_RTLGENRANDOM) + #include <botan/dyn_load.h> + #define NOMINMAX 1 + #define _WINSOCKAPI_ // stop windows.h including winsock.h + #include <windows.h> + +#elif defined(BOTAN_TARGET_OS_HAS_CRYPTO_NG) + #include <bcrypt.h> + +#elif defined(BOTAN_TARGET_OS_HAS_ARC4RANDOM) + #include <stdlib.h> + +#elif defined(BOTAN_TARGET_OS_HAS_DEV_RANDOM) + #include <sys/types.h> + #include <sys/stat.h> + #include <fcntl.h> + #include <unistd.h> + #include <errno.h> +#endif + +namespace Botan { + +namespace { + +#if defined(BOTAN_TARGET_OS_HAS_RTLGENRANDOM) + +class System_RNG_Impl final : public RandomNumberGenerator + { + public: + System_RNG_Impl() : m_advapi("advapi32.dll") + { + // This throws if the function is not found + m_rtlgenrandom = m_advapi.resolve<RtlGenRandom_fptr>("SystemFunction036"); + } + + void randomize(uint8_t buf[], size_t len) override + { + bool success = m_rtlgenrandom(buf, len) == TRUE; + if(!success) + throw Exception("RtlGenRandom failed"); + } + + void add_entropy(const uint8_t[], size_t) override { /* ignored */ } + bool is_seeded() const override { return true; } + void clear() override { /* not possible */ } + std::string name() const override { return "RtlGenRandom"; } + private: + // Use type BYTE instead of BOOLEAN because of a naming conflict + // https://msdn.microsoft.com/en-us/library/windows/desktop/aa387694(v=vs.85).aspx + // https://msdn.microsoft.com/en-us/library/windows/desktop/aa383751(v=vs.85).aspx + using RtlGenRandom_fptr = BYTE (NTAPI *)(PVOID, ULONG); + + Dynamically_Loaded_Library m_advapi; + RtlGenRandom_fptr m_rtlgenrandom; + }; + +#elif defined(BOTAN_TARGET_OS_HAS_CRYPTO_NG) + +class System_RNG_Impl final : public RandomNumberGenerator + { + public: + System_RNG_Impl() + { + NTSTATUS ret = ::BCryptOpenAlgorithmProvider(&m_prov, + BCRYPT_RNG_ALGORITHM, + MS_PRIMITIVE_PROVIDER, 0); + if(ret != STATUS_SUCCESS) + throw Exception("System_RNG failed to acquire crypto provider"); + } + + ~System_RNG_Impl() + { + ::BCryptCloseAlgorithmProvider(m_prov, 0); + } + + void randomize(uint8_t buf[], size_t len) override + { + NTSTATUS ret = ::BCryptGenRandom(m_prov, static_cast<PUCHAR>(buf), static_cast<ULONG>(len), 0); + if(ret != STATUS_SUCCESS) + throw Exception("System_RNG call to BCryptGenRandom failed"); + } + + void add_entropy(const uint8_t in[], size_t length) override + { + /* + There is a flag BCRYPT_RNG_USE_ENTROPY_IN_BUFFER to provide + entropy inputs, but it is ignored in Windows 8 and later. + */ + } + + bool is_seeded() const override { return true; } + void clear() override { /* not possible */ } + std::string name() const override { return "crypto_ng"; } + private: + BCRYPT_ALG_HANDLE m_handle; + }; + +#elif defined(BOTAN_TARGET_OS_HAS_ARC4RANDOM) + +class System_RNG_Impl final : public RandomNumberGenerator + { + public: + // No constructor or destructor needed as no userland state maintained + + void randomize(uint8_t buf[], size_t len) override + { + ::arc4random_buf(buf, len); + } + + void add_entropy(const uint8_t[], size_t) override { /* ignored */ } + bool is_seeded() const override { return true; } + void clear() override { /* not possible */ } + std::string name() const override { return "arc4random"; } + }; + +#elif defined(BOTAN_TARGET_OS_HAS_DEV_RANDOM) + +// Read a random device + +class System_RNG_Impl final : public RandomNumberGenerator + { + public: + System_RNG_Impl() + { + #ifndef O_NOCTTY + #define O_NOCTTY 0 + #endif + + m_fd = ::open(BOTAN_SYSTEM_RNG_DEVICE, O_RDWR | O_NOCTTY); + + /* + Cannot open in read-write mode. Fall back to read-only, + calls to add_entropy will fail, but randomize will work + */ + if(m_fd < 0) + m_fd = ::open(BOTAN_SYSTEM_RNG_DEVICE, O_RDONLY | O_NOCTTY); + + if(m_fd < 0) + throw Exception("System_RNG failed to open RNG device"); + } + + ~System_RNG_Impl() + { + ::close(m_fd); + m_fd = -1; + } + + void randomize(uint8_t buf[], size_t len) override; + void add_entropy(const uint8_t in[], size_t length) override; + bool is_seeded() const override { return true; } + void clear() override { /* not possible */ } + std::string name() const override { return BOTAN_SYSTEM_RNG_DEVICE; } + private: + int m_fd; + }; + +void System_RNG_Impl::randomize(uint8_t buf[], size_t len) + { + while(len) + { + ssize_t got = ::read(m_fd, buf, len); + + if(got < 0) + { + if(errno == EINTR) + continue; + throw Exception("System_RNG read failed error " + std::to_string(errno)); + } + if(got == 0) + throw Exception("System_RNG EOF on device"); // ?!? + + buf += got; + len -= got; + } + } + +void System_RNG_Impl::add_entropy(const uint8_t input[], size_t len) + { + while(len) + { + ssize_t got = ::write(m_fd, input, len); + + if(got < 0) + { + if(errno == EINTR) + continue; + + /* + * This is seen on OS X CI, despite the fact that the man page + * for Darwin urandom explicitly states that writing to it is + * supported, and write(2) does not document EPERM at all. + * But in any case EPERM seems indicative of a policy decision + * by the OS or sysadmin that additional entropy is not wanted + * in the system pool, so we accept that and return here, + * since there is no corrective action possible. + * + * In Linux EBADF or EPERM is returned if m_fd is not opened for + * writing. + */ + if(errno == EPERM || errno == EBADF) + return; + + // maybe just ignore any failure here and return? + throw Exception("System_RNG write failed error " + std::to_string(errno)); + } + + input += got; + len -= got; + } + } + +#endif + +} + +RandomNumberGenerator& system_rng() + { + static System_RNG_Impl g_system_rng; + return g_system_rng; + } + +} |