Crypto: Added public key encryption / decryption.

src/Crypto.cpp

@@ -229,6 +229,81 @@ int cRSAPrivateKey::Encrypt(const Byte * a_PlainData, size_t a_PlainLength, Byte
 
 
 
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// 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:
 

src/Crypto.h

@@ -14,6 +14,7 @@
 #include "polarssl/entropy.h"
 #include "polarssl/ctr_drbg.h"
 #include "polarssl/sha1.h"
+#include "polarssl/pk.h"
 
 
 
@@ -62,6 +63,36 @@ protected:
 
 
 
+class cPublicKey
+{
+public:
+	cPublicKey(const AString & a_PublicKeyDER);
+	~cPublicKey();
+	
+	/** Decrypts the data using the stored public key
+	Both a_EncryptedData and a_DecryptedData must be at least <KeySizeBytes> bytes large.
+	Returns the number of bytes decrypted, or negative number for error. */
+	int Decrypt(const Byte * a_EncryptedData, size_t a_EncryptedLength, Byte * a_DecryptedData, size_t a_DecryptedMaxLength);
+	
+	/** Encrypts the data using the stored public key
+	Both a_EncryptedData and a_DecryptedData must be at least <KeySizeBytes> bytes large.
+	Returns the number of bytes decrypted, or negative number for error. */
+	int Encrypt(const Byte * a_PlainData, size_t a_PlainLength, Byte * a_EncryptedData, size_t a_EncryptedMaxLength);
+
+protected:
+	pk_context m_Pk;
+	entropy_context m_Entropy;
+	ctr_drbg_context m_Ctr_drbg;
+	
+	/** Initializes the m_Entropy and m_Ctr_drbg contexts
+	Common part of this object's construction, called from all constructors. */
+	void InitRnd(void);
+} ;
+
+
+
+
+
 /** Decrypts data using the AES / CFB (128) algorithm */
 class cAESCFBDecryptor
 {