diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/aes.cpp | 115 |
1 files changed, 62 insertions, 53 deletions
diff --git a/src/aes.cpp b/src/aes.cpp index 033d8beb2..8ec6dd3bc 100644 --- a/src/aes.cpp +++ b/src/aes.cpp @@ -14,8 +14,9 @@ * --------------------------------------------------- */ -// Based on existing implementations of the industry standard AES algorithms -// in the public domain. +/* Based on existing implementations of the industry + * standard AES algorithms in the public domain. + */ #include <cstring> #include "aes.h" @@ -932,24 +933,31 @@ const int AES::sm_shifts[3][4][2] = { {0, 0}, {1, 7}, {3, 5}, {4, 4} } }; -//Null chain +/** + * Null chain + */ char const* AES::sm_chain0 = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"; -//CONSTRUCTOR +/** + * CONSTRUCTOR + */ AES::AES() : m_bKeyInit(false) { } -//DESTRUCTOR +/** + * DESTRUCTOR + */ AES::~AES() { } -//Expand a user-supplied key material into a session key. -// key - The 128/192/256-bit user-key to use. -// chain - initial chain block for CBC and CFB modes. -// keylength - 16, 24 or 32 bytes -// blockSize - The block size in bytes of this Rijndael (16, 24 or 32 bytes). +/** Expand a user-supplied key material into a session key. + * @param key The 128/192/256-bit user-key to use. + * @param chain initial chain block for CBC and CFB modes. + * @param keylength 16, 24 or 32 bytes + * @param blockSize The block size in bytes of this Rijndael (16, 24 or 32 bytes). + */ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSize) { if (NULL == key) @@ -960,10 +968,10 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi return; m_keylength = keylength; m_blockSize = blockSize; - //Initialize the chain + /* Initialize the chain */ memcpy(m_chain0, chain, m_blockSize); memcpy(m_chain, chain, m_blockSize); - //Calculate Number of Rounds + /* Calculate Number of Rounds */ switch (m_keylength) { case 16: @@ -974,7 +982,7 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi m_iROUNDS = (m_blockSize != 32) ? 12 : 14; break; - default: // 32 bytes = 256 bits + default: /* 32 bytes = 256 bits */ m_iROUNDS = 14; } int BC = m_blockSize / 4; @@ -991,7 +999,7 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi } int ROUND_KEY_COUNT = (m_iROUNDS + 1) * BC; int KC = m_keylength/4; - //Copy user material bytes into temporary ints + /* Copy user material bytes into temporary ints */ int* pi = tk; char const* pc = key; for (i=0; i<KC; i++) @@ -1001,7 +1009,7 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi *pi |= (unsigned char)*(pc++) << 8; *(pi++) |= (unsigned char)*(pc++); } - //Copy values into round key arrays + /* Copy values into round key arrays */ int t = 0; for (j=0; (j<KC)&&(t<ROUND_KEY_COUNT); j++,t++) { @@ -1011,7 +1019,7 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi int tt, rconpointer = 0; while (t < ROUND_KEY_COUNT) { - //Extrapolate using phi (the round key evolution function) + /* Extrapolate using phi (the round key evolution function) */ tt = tk[KC-1]; tk[0] ^= (sm_S[(tt >> 16) & 0xFF] & 0xFF) << 24 ^ (sm_S[(tt >> 8) & 0xFF] & 0xFF) << 16 ^ @@ -1033,14 +1041,14 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi for (j = KC/2, i=j+1; i<KC; ) tk[i++] ^= tk[j++]; } - //Copy values into round key arrays + /* Copy values into round key arrays */ for (j=0; (j<KC) && (t<ROUND_KEY_COUNT); j++, t++) { m_Ke[t/BC][t%BC] = tk[j]; m_Kd[m_iROUNDS - (t/BC)][t%BC] = tk[j]; } } - //Inverse MixColumn where needed + /* Inverse MixColumn where needed */ for (int r=1; r<m_iROUNDS; r++) for (j=0; j<BC; j++) { @@ -1053,10 +1061,10 @@ void AES::MakeKey(char const* key, char const* chain, int keylength, int blockSi m_bKeyInit = true; } -//Convenience method to encrypt exactly one block of plaintext, assuming -//Rijndael's default block size (128-bit). -// in - The plaintext -// result - The ciphertext generated from a plaintext using the key +/** Convenience method to encrypt exactly one block of plaintext, assuming Rijndael's default block size (128-bit). + * @param in The plaintext + * @returns The ciphertext generated from a plaintext using the key + */ void AES::DefEncryptBlock(char const* in, char* result) { if (m_bKeyInit == false) @@ -1079,7 +1087,7 @@ void AES::DefEncryptBlock(char const* in, char* result) t3 |= ((unsigned char)*(in++) << 8); (t3 |= (unsigned char)*(in++)) ^= Ker[3]; int a0, a1, a2, a3; - //Apply Round Transforms + /* Apply round transforms */ for (int r = 1; r < m_iROUNDS; r++) { Ker = m_Ke[r]; @@ -1104,7 +1112,7 @@ void AES::DefEncryptBlock(char const* in, char* result) t2 = a2; t3 = a3; } - //Last Round is special + /* Last round is special */ Ker = m_Ke[m_iROUNDS]; int tt = Ker[0]; result[0] = sm_S[(t0 >> 24) & 0xFF] ^ (tt >> 24); @@ -1128,10 +1136,10 @@ void AES::DefEncryptBlock(char const* in, char* result) result[15] = sm_S[t2 & 0xFF] ^ tt; } -//Convenience method to decrypt exactly one block of plaintext, assuming -//Rijndael's default block size (128-bit). -// in - The ciphertext. -// result - The plaintext generated from a ciphertext using the session key. +/** Convenience method to decrypt exactly one block of plaintext, assuming Rijndael's default block size (128-bit). + * @param in The ciphertext. + * @return The plaintext generated from a ciphertext using the session key. + */ void AES::DefDecryptBlock(char const* in, char* result) { if (m_bKeyInit == false) @@ -1154,7 +1162,7 @@ void AES::DefDecryptBlock(char const* in, char* result) t3 |= ((unsigned char)*(in++) << 8); (t3 |= (unsigned char)*(in++)) ^= Kdr[3]; int a0, a1, a2, a3; - for (int r = 1; r < m_iROUNDS; r++) // apply round transforms + for (int r = 1; r < m_iROUNDS; r++) /* apply round transforms */ { Kdr = m_Kd[r]; a0 = (sm_T5[(t0 >> 24) & 0xFF] ^ @@ -1178,7 +1186,7 @@ void AES::DefDecryptBlock(char const* in, char* result) t2 = a2; t3 = a3; } - //Last Round is special + /* Last round is special */ Kdr = m_Kd[m_iROUNDS]; int tt = Kdr[0]; result[ 0] = sm_Si[(t0 >> 24) & 0xFF] ^ (tt >> 24); @@ -1202,9 +1210,10 @@ void AES::DefDecryptBlock(char const* in, char* result) result[15] = sm_Si[ t0 & 0xFF] ^ tt; } -//Encrypt exactly one block of plaintext. -// in - The plaintext. -// result - The ciphertext generated from a plaintext using the key. +/** Encrypt exactly one block of plaintext. + * @param in The plaintext. + * @return The ciphertext generated from a plaintext using the key. + */ void AES::EncryptBlock(char const* in, char* result) { if (m_bKeyInit == false) @@ -1219,7 +1228,7 @@ void AES::EncryptBlock(char const* in, char* result) int s1 = sm_shifts[SC][1][0]; int s2 = sm_shifts[SC][2][0]; int s3 = sm_shifts[SC][3][0]; - //Temporary Work Arrays + /* Temporary work arrays */ int i; int tt; int* pi = t; @@ -1230,7 +1239,7 @@ void AES::EncryptBlock(char const* in, char* result) *pi |= ((unsigned char)*(in++) << 8); (*(pi++) |= (unsigned char)*(in++)) ^= m_Ke[0][i]; } - //Apply Round Transforms + /* Apply round transforms */ for (int r=1; r<m_iROUNDS; r++) { for (i=0; i<BC; i++) @@ -1241,7 +1250,7 @@ void AES::EncryptBlock(char const* in, char* result) memcpy(t, a, 4*BC); } int j; - //Last Round is Special + /* Last round is special */ for (i=0,j=0; i<BC; i++) { tt = m_Ke[m_iROUNDS][i]; @@ -1252,9 +1261,10 @@ void AES::EncryptBlock(char const* in, char* result) } } -//Decrypt exactly one block of ciphertext. -// in - The ciphertext. -// result - The plaintext generated from a ciphertext using the session key. +/** Decrypt exactly one block of ciphertext. + * @param inThe ciphertext. + * @return The plaintext generated from a ciphertext using the session key. + */ void AES::DecryptBlock(char const* in, char* result) { if (m_bKeyInit == false) @@ -1269,7 +1279,7 @@ void AES::DecryptBlock(char const* in, char* result) int s1 = sm_shifts[SC][1][1]; int s2 = sm_shifts[SC][2][1]; int s3 = sm_shifts[SC][3][1]; - //Temporary Work Arrays + /* Temporary work arrays */ int i; int tt; int* pi = t; @@ -1280,7 +1290,7 @@ void AES::DecryptBlock(char const* in, char* result) *pi |= ((unsigned char)*(in++) << 8); (*(pi++) |= (unsigned char)*(in++)) ^= m_Kd[0][i]; } - //Apply Round Transforms + /* Apply round transforms */ for (int r=1; r<m_iROUNDS; r++) { for (i=0; i<BC; i++) @@ -1291,7 +1301,7 @@ void AES::DecryptBlock(char const* in, char* result) memcpy(t, a, 4*BC); } int j; - //Last Round is Special + /* Last round is special */ for (i=0,j=0; i<BC; i++) { tt = m_Kd[m_iROUNDS][i]; @@ -1306,13 +1316,13 @@ void AES::Encrypt(char const* in, char* result, size_t n, int iMode) { if (m_bKeyInit == false) return; - //n should be > 0 and multiple of m_blockSize + /* n should be > 0 and multiple of m_blockSize */ if (n == 0 || n%m_blockSize!=0) return; unsigned int i; char const* pin; char* presult; - if (CBC == iMode) //CBC mode, using the Chain + if (CBC == iMode) /* CBC mode, using the chain */ { for (i=0,pin=in,presult=result; i<n/m_blockSize; i++) { @@ -1323,7 +1333,7 @@ void AES::Encrypt(char const* in, char* result, size_t n, int iMode) presult += m_blockSize; } } - else if (CFB == iMode) //CFB mode, using the Chain + else if (CFB == iMode) /* CFB mode, using the chain */ { for (i=0,pin=in,presult=result; i<n/m_blockSize; i++) { @@ -1334,7 +1344,7 @@ void AES::Encrypt(char const* in, char* result, size_t n, int iMode) presult += m_blockSize; } } - else //ECB mode, not using the Chain + else /* ECB mode, not using the chain */ { for (i=0,pin=in,presult=result; i<n/m_blockSize; i++) { @@ -1349,13 +1359,13 @@ void AES::Decrypt(char const* in, char* result, size_t n, int iMode) { if (m_bKeyInit == false) return; - //n should be > 0 and multiple of m_blockSize + /* n should be > 0 and multiple of m_blockSize */ if (n == 0 || n%m_blockSize!=0) return; unsigned int i; char const* pin; char* presult; - if (CBC == iMode) //CBC mode, using the Chain + if (CBC == iMode) /* CBC mode, using the chain */ { for (i=0,pin=in,presult=result; i<n/m_blockSize; i++) { @@ -1366,19 +1376,18 @@ void AES::Decrypt(char const* in, char* result, size_t n, int iMode) presult += m_blockSize; } } - else if (CFB == iMode) //CFB mode, using the Chain, not using Decrypt() + else if (CFB == iMode) /* CFB mode, using the chain, not using Decrypt() */ { for (i=0,pin=in,presult=result; i<n/m_blockSize; i++) { EncryptBlock(m_chain, presult); - //memcpy(presult, pin, m_blockSize); Xor(presult, pin); memcpy(m_chain, pin, m_blockSize); pin += m_blockSize; presult += m_blockSize; } } - else //ECB mode, not using the Chain + else /* ECB mode, not using the Chain */ { for (i=0,pin=in,presult=result; i<n/m_blockSize; i++) { @@ -1408,7 +1417,7 @@ static const char base64val[] = { #define DECODE64(c) (c < 128 ? base64val[c] : BAD) void to64frombits(unsigned char *out, const unsigned char *in, int inlen) -/* raw bytes in quasi-big-endian order to base 64 string (NUL-terminated) */ +/* Raw bytes to base 64 string (NUL-terminated) */ { for (; inlen >= 3; inlen -= 3) { @@ -1434,7 +1443,7 @@ void to64frombits(unsigned char *out, const unsigned char *in, int inlen) } int from64tobits(char *out, const char *in, int maxlen) -/* base 64 to raw bytes in quasi-big-endian order, returning count of bytes */ +/* base 64 to raw bytes, returning count of bytes */ /* maxlen limits output buffer size, set to zero to ignore */ { int len = 0; |