1 files changed, 509 insertions, 0 deletions

diff --git a/src/Crypto.cpp b/src/Crypto.cpp
new file mode 100644
index 000000000..26500f263
--- /dev/null
+++ b/src/Crypto.cpp
@@ -0,0 +1,509 @@
+
+// Crypto.cpp
+
+// Implements classes that wrap the cryptographic code library
+
+#include "Globals.h"
+#include "Crypto.h"
+
+#include "polarssl/pk.h"
+
+
+
+
+
+/*
+// Self-test the hash formatting for known values:
+// sha1(Notch) : 4ed1f46bbe04bc756bcb17c0c7ce3e4632f06a48
+// sha1(jeb_)  : -7c9d5b0044c130109a5d7b5fb5c317c02b4e28c1
+// sha1(simon) : 88e16a1019277b15d58faf0541e11910eb756f6
+
+class Test
+{
+public:
+	Test(void)
+	{
+		AString DigestNotch, DigestJeb, DigestSimon;
+		Byte Digest[20];
+		cSHA1Checksum Checksum;
+		Checksum.Update((const Byte *)"Notch", 5);
+		Checksum.Finalize(Digest);
+		cSHA1Checksum::DigestToJava(Digest, DigestNotch);
+		Checksum.Restart();
+		Checksum.Update((const Byte *)"jeb_", 4);
+		Checksum.Finalize(Digest);
+		cSHA1Checksum::DigestToJava(Digest, DigestJeb);
+		Checksum.Restart();
+		Checksum.Update((const Byte *)"simon", 5);
+		Checksum.Finalize(Digest);
+		cSHA1Checksum::DigestToJava(Digest, DigestSimon);
+		printf("Notch: \"%s\"\n", DigestNotch.c_str());
+		printf("jeb_:  \"%s\"\n",  DigestJeb.c_str());
+		printf("simon: \"%s\"\n", DigestSimon.c_str());
+		assert(DigestNotch == "4ed1f46bbe04bc756bcb17c0c7ce3e4632f06a48");
+		assert(DigestJeb   == "-7c9d5b0044c130109a5d7b5fb5c317c02b4e28c1");
+		assert(DigestSimon == "88e16a1019277b15d58faf0541e11910eb756f6");
+	}
+} test;
+*/
+
+
+
+
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cRSAPrivateKey:
+
+cRSAPrivateKey::cRSAPrivateKey(void)
+{
+	rsa_init(&m_Rsa, RSA_PKCS_V15, 0);
+	InitRnd();
+}
+
+
+
+
+
+cRSAPrivateKey::cRSAPrivateKey(const cRSAPrivateKey & a_Other)
+{
+	rsa_init(&m_Rsa, RSA_PKCS_V15, 0);
+	rsa_copy(&m_Rsa, &a_Other.m_Rsa);
+	InitRnd();
+}
+
+
+
+
+
+cRSAPrivateKey::~cRSAPrivateKey()
+{
+	entropy_free(&m_Entropy);
+	rsa_free(&m_Rsa);
+}
+
+
+
+
+
+void cRSAPrivateKey::InitRnd(void)
+{
+	entropy_init(&m_Entropy);
+	const unsigned char pers[] = "rsa_genkey";
+	ctr_drbg_init(&m_Ctr_drbg, entropy_func, &m_Entropy, pers, sizeof(pers) - 1);
+}
+
+
+
+
+
+bool cRSAPrivateKey::Generate(unsigned a_KeySizeBits)
+{
+	if (rsa_gen_key(&m_Rsa, ctr_drbg_random, &m_Ctr_drbg, a_KeySizeBits, 65537) != 0)
+	{
+		// Key generation failed
+		return false;
+	}
+
+	return true;
+}
+
+
+
+
+
+AString cRSAPrivateKey::GetPubKeyDER(void)
+{
+	class cPubKey
+	{
+	public:
+		cPubKey(rsa_context * a_Rsa) :
+			m_IsValid(false)
+		{
+			pk_init(&m_Key);
+			if (pk_init_ctx(&m_Key, pk_info_from_type(POLARSSL_PK_RSA)) != 0)
+			{
+				ASSERT(!"Cannot init PrivKey context");
+				return;
+			}
+			if (rsa_copy(pk_rsa(m_Key), a_Rsa) != 0)
+			{
+				ASSERT(!"Cannot copy PrivKey to PK context");
+				return;
+			}
+			m_IsValid = true;
+		}
+		
+		~cPubKey()
+		{
+			if (m_IsValid)
+			{
+				pk_free(&m_Key);
+			}
+		}
+		
+		operator pk_context * (void) { return &m_Key; }
+		
+	protected:
+		bool m_IsValid;
+		pk_context m_Key;
+	} PkCtx(&m_Rsa);
+	
+	unsigned char buf[3000];
+	int res = pk_write_pubkey_der(PkCtx, buf, sizeof(buf));
+	if (res < 0)
+	{
+		return AString();
+	}
+	return AString((const char *)(buf + sizeof(buf) - res), (size_t)res);
+}
+
+
+
+
+
+int cRSAPrivateKey::Decrypt(const Byte * a_EncryptedData, size_t a_EncryptedLength, Byte * a_DecryptedData, size_t a_DecryptedMaxLength)
+{
+	if (a_EncryptedLength < m_Rsa.len)
+	{
+		LOGD("%s: Invalid a_EncryptedLength: got %u, exp at least %u",
+			__FUNCTION__, (unsigned)a_EncryptedLength, (unsigned)(m_Rsa.len)
+		);
+		ASSERT(!"Invalid a_DecryptedMaxLength!");
+		return -1;
+	}
+	if (a_DecryptedMaxLength < m_Rsa.len)
+	{
+		LOGD("%s: Invalid a_DecryptedMaxLength: got %u, exp at least %u",
+			__FUNCTION__, (unsigned)a_EncryptedLength, (unsigned)(m_Rsa.len)
+		);
+		ASSERT(!"Invalid a_DecryptedMaxLength!");
+		return -1;
+	}
+	size_t DecryptedLength;
+	int res = rsa_pkcs1_decrypt(
+		&m_Rsa, ctr_drbg_random, &m_Ctr_drbg, RSA_PRIVATE, &DecryptedLength,
+		a_EncryptedData, a_DecryptedData, a_DecryptedMaxLength
+	);
+	if (res != 0)
+	{
+		return -1;
+	}
+	return (int)DecryptedLength;
+}
+
+
+
+
+
+int cRSAPrivateKey::Encrypt(const Byte * a_PlainData, size_t a_PlainLength, Byte * a_EncryptedData, size_t a_EncryptedMaxLength)
+{
+	if (a_EncryptedMaxLength < m_Rsa.len)
+	{
+		LOGD("%s: Invalid a_EncryptedMaxLength: got %u, exp at least %u",
+			__FUNCTION__, (unsigned)a_EncryptedMaxLength, (unsigned)(m_Rsa.len)
+		);
+		ASSERT(!"Invalid a_DecryptedMaxLength!");
+		return -1;
+	}
+	if (a_EncryptedMaxLength < m_Rsa.len)
+	{
+		LOGD("%s: Invalid a_PlainLength: got %u, exp at least %u",
+			__FUNCTION__, (unsigned)a_PlainLength, (unsigned)(m_Rsa.len)
+		);
+		ASSERT(!"Invalid a_PlainLength!");
+		return -1;
+	}
+	int res = rsa_pkcs1_encrypt(
+		&m_Rsa, ctr_drbg_random, &m_Ctr_drbg, RSA_PRIVATE,
+		a_PlainLength, a_PlainData, a_EncryptedData
+	);
+	if (res != 0)
+	{
+		return -1;
+	}
+	return (int)m_Rsa.len;
+}
+
+
+
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cPublicKey:
+
+cPublicKey::cPublicKey(const AString & a_PublicKeyDER)
+{
+	pk_init(&m_Pk);
+	if (pk_parse_public_key(&m_Pk, (const Byte *)a_PublicKeyDER.data(), a_PublicKeyDER.size()) != 0)
+	{
+		ASSERT(!"Cannot parse PubKey");
+		return;
+	}
+	InitRnd();
+}
+
+
+
+
+
+cPublicKey::~cPublicKey()
+{
+	pk_free(&m_Pk);
+}
+
+
+
+
+
+int cPublicKey::Decrypt(const Byte * a_EncryptedData, size_t a_EncryptedLength, Byte * a_DecryptedData, size_t a_DecryptedMaxLength)
+{
+	size_t DecryptedLen = a_DecryptedMaxLength;
+	int res = pk_decrypt(&m_Pk,
+		a_EncryptedData, a_EncryptedLength,
+		a_DecryptedData, &DecryptedLen, a_DecryptedMaxLength,
+		ctr_drbg_random, &m_Ctr_drbg
+	);
+	if (res != 0)
+	{
+		return res;
+	}
+	return (int)DecryptedLen;
+}
+
+
+
+
+
+int cPublicKey::Encrypt(const Byte * a_PlainData, size_t a_PlainLength, Byte * a_EncryptedData, size_t a_EncryptedMaxLength)
+{
+	size_t EncryptedLength = a_EncryptedMaxLength;
+	int res = pk_encrypt(&m_Pk,
+		a_PlainData, a_PlainLength, a_EncryptedData, &EncryptedLength, a_EncryptedMaxLength,
+		ctr_drbg_random, &m_Ctr_drbg
+	);
+	if (res != 0)
+	{
+		return res;
+	}
+	return (int)EncryptedLength;
+}
+
+
+
+
+
+void cPublicKey::InitRnd(void)
+{
+	entropy_init(&m_Entropy);
+	const unsigned char pers[] = "rsa_genkey";
+	ctr_drbg_init(&m_Ctr_drbg, entropy_func, &m_Entropy, pers, sizeof(pers) - 1);
+}
+
+
+
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cAESCFBDecryptor:
+
+cAESCFBDecryptor::cAESCFBDecryptor(void) :
+	m_IVOffset(0),
+	m_IsValid(false)
+{
+}
+
+
+
+
+
+cAESCFBDecryptor::~cAESCFBDecryptor()
+{
+	// Clear the leftover in-memory data, so that they can't be accessed by a backdoor
+	memset(&m_Aes, 0, sizeof(m_Aes));
+}
+
+
+
+
+
+void cAESCFBDecryptor::Init(const Byte a_Key[16], const Byte a_IV[16])
+{
+	ASSERT(!IsValid());  // Cannot Init twice
+	
+	memcpy(m_IV, a_IV, 16);
+	aes_setkey_enc(&m_Aes, a_Key, 128);
+	m_IsValid = true;
+}
+
+
+
+
+
+void cAESCFBDecryptor::ProcessData(Byte * a_DecryptedOut, const Byte * a_EncryptedIn, size_t a_Length)
+{
+	ASSERT(IsValid());  // Must Init() first
+	
+	// PolarSSL doesn't support AES-CFB8, need to implement it manually:
+	for (size_t i = 0; i < a_Length; i++)
+	{
+		Byte Buffer[sizeof(m_IV)];
+		aes_crypt_ecb(&m_Aes, AES_ENCRYPT, m_IV, Buffer);
+		for (size_t idx = 0; idx < sizeof(m_IV) - 1; idx++)
+		{
+			m_IV[idx] = m_IV[idx + 1];
+		}
+		m_IV[sizeof(m_IV) - 1] = a_EncryptedIn[i];
+		a_DecryptedOut[i] = a_EncryptedIn[i] ^ Buffer[0];
+	}
+}
+
+
+
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cAESCFBEncryptor:
+
+cAESCFBEncryptor::cAESCFBEncryptor(void) :
+	m_IVOffset(0),
+	m_IsValid(false)
+{
+}
+
+
+
+
+
+cAESCFBEncryptor::~cAESCFBEncryptor()
+{
+	// Clear the leftover in-memory data, so that they can't be accessed by a backdoor
+	memset(&m_Aes, 0, sizeof(m_Aes));
+}
+
+
+
+
+
+void cAESCFBEncryptor::Init(const Byte a_Key[16], const Byte a_IV[16])
+{
+	ASSERT(!IsValid());  // Cannot Init twice
+	ASSERT(m_IVOffset == 0);
+	
+	memcpy(m_IV, a_IV, 16);
+	aes_setkey_enc(&m_Aes, a_Key, 128);
+	m_IsValid = true;
+}
+
+
+
+
+
+void cAESCFBEncryptor::ProcessData(Byte * a_EncryptedOut, const Byte * a_PlainIn, size_t a_Length)
+{
+	ASSERT(IsValid());  // Must Init() first
+	
+	// PolarSSL doesn't do AES-CFB8, so we need to implement it ourselves:
+	for (size_t i = 0; i < a_Length; i++)
+	{
+		Byte Buffer[sizeof(m_IV)];
+		aes_crypt_ecb(&m_Aes, AES_ENCRYPT, m_IV, Buffer);
+		for (size_t idx = 0; idx < sizeof(m_IV) - 1; idx++)
+		{
+			m_IV[idx] = m_IV[idx + 1];
+		}
+		a_EncryptedOut[i] = a_PlainIn[i] ^ Buffer[0];
+		m_IV[sizeof(m_IV) - 1] = a_EncryptedOut[i];
+	}
+}
+
+
+
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cSHA1Checksum:
+
+cSHA1Checksum::cSHA1Checksum(void) :
+	m_DoesAcceptInput(true)
+{
+	sha1_starts(&m_Sha1);
+}
+
+
+
+
+
+void cSHA1Checksum::Update(const Byte * a_Data, size_t a_Length)
+{
+	ASSERT(m_DoesAcceptInput);  // Not Finalize()-d yet, or Restart()-ed
+	
+	sha1_update(&m_Sha1, a_Data, a_Length);
+}
+
+
+
+
+
+void cSHA1Checksum::Finalize(cSHA1Checksum::Checksum & a_Output)
+{
+	ASSERT(m_DoesAcceptInput);  // Not Finalize()-d yet, or Restart()-ed
+	
+	sha1_finish(&m_Sha1, a_Output);
+	m_DoesAcceptInput = false;
+}
+
+
+
+
+
+void cSHA1Checksum::DigestToJava(const Checksum & a_Digest, AString & a_Out)
+{
+	Checksum Digest;
+	memcpy(Digest, a_Digest, sizeof(Digest));
+	
+	bool IsNegative = (Digest[0] >= 0x80);
+	if (IsNegative)
+	{
+		// Two's complement:
+		bool carry = true;  // Add one to the whole number
+		for (int i = 19; i >= 0; i--)
+		{
+			Digest[i] = ~Digest[i];
+			if (carry)
+			{
+				carry = (Digest[i] == 0xff);
+				Digest[i]++;
+			}
+		}
+	}
+	a_Out.clear();
+	a_Out.reserve(40);
+	for (int i = 0; i < 20; i++)
+	{
+		AppendPrintf(a_Out, "%02x", Digest[i]);
+	}
+	while ((a_Out.length() > 0) && (a_Out[0] == '0'))
+	{
+		a_Out.erase(0, 1);
+	}
+	if (IsNegative)
+	{
+		a_Out.insert(0, "-");
+	}
+}
+
+
+
+
+
+
+void cSHA1Checksum::Restart(void)
+{
+	sha1_starts(&m_Sha1);
+	m_DoesAcceptInput = true;
+}
+
+
+
+