#define _WIN32_WINNT 0x0400
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <wincrypt.h>
#include "ssh.h"
void fatalbox(char *fmt, ...);
static HCRYPTKEY create_des_key(unsigned char *key);
HCRYPTPROV hCryptProv;
HCRYPTKEY hDESKey[2][3] = {{0,0,0},{0,0,0}}; /* global for now */
/* use Microsoft Enhanced Cryptographic Service Provider */
#define CSP MS_ENHANCED_PROV
static BYTE PrivateKeyWithExponentOfOne[] =
{
0x07, 0x02, 0x00, 0x00, 0x00, 0xA4, 0x00, 0x00,
0x52, 0x53, 0x41, 0x32, 0x00, 0x02, 0x00, 0x00,
0x01, 0x00, 0x00, 0x00, 0xAB, 0xEF, 0xFA, 0xC6,
0x7D, 0xE8, 0xDE, 0xFB, 0x68, 0x38, 0x09, 0x92,
0xD9, 0x42, 0x7E, 0x6B, 0x89, 0x9E, 0x21, 0xD7,
0x52, 0x1C, 0x99, 0x3C, 0x17, 0x48, 0x4E, 0x3A,
0x44, 0x02, 0xF2, 0xFA, 0x74, 0x57, 0xDA, 0xE4,
0xD3, 0xC0, 0x35, 0x67, 0xFA, 0x6E, 0xDF, 0x78,
0x4C, 0x75, 0x35, 0x1C, 0xA0, 0x74, 0x49, 0xE3,
0x20, 0x13, 0x71, 0x35, 0x65, 0xDF, 0x12, 0x20,
0xF5, 0xF5, 0xF5, 0xC1, 0xED, 0x5C, 0x91, 0x36,
0x75, 0xB0, 0xA9, 0x9C, 0x04, 0xDB, 0x0C, 0x8C,
0xBF, 0x99, 0x75, 0x13, 0x7E, 0x87, 0x80, 0x4B,
0x71, 0x94, 0xB8, 0x00, 0xA0, 0x7D, 0xB7, 0x53,
0xDD, 0x20, 0x63, 0xEE, 0xF7, 0x83, 0x41, 0xFE,
0x16, 0xA7, 0x6E, 0xDF, 0x21, 0x7D, 0x76, 0xC0,
0x85, 0xD5, 0x65, 0x7F, 0x00, 0x23, 0x57, 0x45,
0x52, 0x02, 0x9D, 0xEA, 0x69, 0xAC, 0x1F, 0xFD,
0x3F, 0x8C, 0x4A, 0xD0,
0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x64, 0xD5, 0xAA, 0xB1,
0xA6, 0x03, 0x18, 0x92, 0x03, 0xAA, 0x31, 0x2E,
0x48, 0x4B, 0x65, 0x20, 0x99, 0xCD, 0xC6, 0x0C,
0x15, 0x0C, 0xBF, 0x3E, 0xFF, 0x78, 0x95, 0x67,
0xB1, 0x74, 0x5B, 0x60,
0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
/* ---------------------------------------------------------*
* Utility functions *
* ---------------------------------------------------------*/
int crypto_startup() {
if(CryptAcquireContext(&hCryptProv, "Putty", CSP, PROV_RSA_FULL,
CRYPT_NEWKEYSET) == 0) {
if(GetLastError() == NTE_EXISTS) {
if(CryptAcquireContext(&hCryptProv, "Putty", CSP,
PROV_RSA_FULL, 0) == 0) {
return FALSE; /* failed to acquire context - probably
* don't have high encryption installed! */
}
} else
return FALSE; /* failed to acquire context - probably
* don't have high encryption installed! */
}
return TRUE;
}
void crypto_wrapup() {
int i, j;
for(i=0; i<2; i++) {
for(j=0; j<3; j++) {
if(hDESKey[i][j])
CryptDestroyKey(hDESKey[i][j]);
hDESKey[i][j] = 0;
}
}
if(hCryptProv)
CryptReleaseContext(hCryptProv, 0);
hCryptProv = 0;
}
/* ---------------------------------------------------------*
* Random number functions *
* ---------------------------------------------------------*/
int random_byte(void) {
unsigned char b;
if(!CryptGenRandom(hCryptProv, 1, &b))
fatalbox("random number generator failure!");
return b;
}
void random_add_noise(void *noise, int length) {
/* do nothing */
}
void random_init(void) {
/* do nothing */
}
void random_get_savedata(void **data, int *len) {
/* do nothing */
}
void noise_get_heavy(void (*func) (void *, int)) {
/* do nothing */
}
void noise_get_light(void (*func) (void *, int)) {
/* do nothing */
}
void noise_ultralight(DWORD data) {
/* do nothing */
}
void random_save_seed(void) {
/* do nothing */
}
/* ---------------------------------------------------------*
* MD5 hash functions *
* ---------------------------------------------------------*/
void MD5Init(struct MD5Context *ctx) {
if(!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &ctx->hHash))
fatalbox("Error during CryptBeginHash!\n");
}
void MD5Update(struct MD5Context *ctx,
unsigned char const *buf, unsigned len) {
if(CryptHashData(ctx->hHash, buf, len, 0) == 0)
fatalbox("Error during CryptHashSessionKey!\n");
}
void MD5Final(unsigned char digest[16], struct MD5Context *ctx) {
DWORD cb = 16;
if(CryptGetHashParam(ctx->hHash, HP_HASHVAL, digest, &cb, 0) == 0)
fatalbox("Error during CryptGetHashParam!\n");
if(ctx->hHash)
CryptDestroyHash(ctx->hHash);
ctx->hHash = 0;
}
/* ---------------------------------------------------------*
* RSA public key functions *
* ---------------------------------------------------------*/
int makekey(unsigned char *data, struct RSAKey *result,
unsigned char **keystr) {
unsigned char *p = data;
int i;
int w, b;
/* get size (bits) of modulus */
result->bits = 0;
for(i=0; i<4; i++)
result->bits = (result->bits << 8) + *p++;
/* get size (bits) of public exponent */
w = 0;
for (i=0; i<2; i++)
w = (w << 8) + *p++;
b = (w+7)/8; /* bits -> bytes */
/* convert exponent to DWORD */
result->exponent = 0;
for (i=0; i<b; i++)
result->exponent = (result->exponent << 8) + *p++;
/* get size (bits) of modulus */
w = 0;
for (i=0; i<2; i++)
w = (w << 8) + *p++;
result->bytes = b = (w+7)/8; /* bits -> bytes */
/* allocate buffer for modulus & copy it */
result->modulus = malloc(b);
memcpy(result->modulus, p, b);
/* update callers pointer */
if (keystr) *keystr = p; /* point at key string, second time */
return (p - data) + b;
}
void rsaencrypt(unsigned char *data, int length, struct RSAKey *rsakey) {
int i;
unsigned char *pKeybuf, *pKeyin;
HCRYPTKEY hRsaKey;
PUBLICKEYSTRUC *pBlob;
RSAPUBKEY *pRPK;
unsigned char *buf;
DWORD dlen;
DWORD bufsize;
/* allocate buffer for public key blob */
if((pBlob = malloc(sizeof(PUBLICKEYSTRUC) + sizeof(RSAPUBKEY) +
rsakey->bytes)) == NULL)
fatalbox("Out of memory");
/* allocate buffer for message encryption block */
bufsize = (length + rsakey->bytes) << 1;
if((buf = malloc(bufsize)) == NULL)
fatalbox("Out of memory");
/* construct public key blob from host public key */
pKeybuf = ((unsigned char*)pBlob) + sizeof(PUBLICKEYSTRUC) +
sizeof(RSAPUBKEY);
pKeyin = ((unsigned char*)rsakey->modulus);
/* change big endian to little endian */
for(i=0; i<rsakey->bytes; i++)
pKeybuf[i] = pKeyin[rsakey->bytes-i-1];
pBlob->bType = PUBLICKEYBLOB;
pBlob->bVersion = 0x02;
pBlob->reserved = 0;
pBlob->aiKeyAlg = CALG_RSA_KEYX;
pRPK = (RSAPUBKEY*)(((unsigned char*)pBlob) + sizeof(PUBLICKEYSTRUC));
pRPK->magic = 0x31415352; /* "RSA1" */
pRPK->bitlen = rsakey->bits;
pRPK->pubexp = rsakey->exponent;
/* import public key blob into key container */
if(CryptImportKey(hCryptProv, (void*)pBlob,
sizeof(PUBLICKEYSTRUC)+sizeof(RSAPUBKEY)+rsakey->bytes,
0, 0, &hRsaKey) == 0)
fatalbox("Error importing RSA key!");
/* copy message into buffer */
memcpy(buf, data, length);
dlen = length;
/* using host public key, encrypt the message */
if(CryptEncrypt(hRsaKey, 0, TRUE, 0, buf, &dlen, bufsize) == 0)
fatalbox("Error encrypting using RSA key!");
/*
* For some strange reason, Microsoft CryptEncrypt using public
* key, returns the cyphertext in backwards (little endian)
* order, so reverse it!
*/
for(i = 0; i < (int)dlen; i++)
data[i] = buf[dlen - i - 1]; /* make it big endian */
CryptDestroyKey(hRsaKey);
free(buf);
free(pBlob);
}
int rsastr_len(struct RSAKey *key) {
return 2 * (sizeof(DWORD) + key->bytes) + 10;
}
void rsastr_fmt(char *str, struct RSAKey *key) {
int len = 0, i;
sprintf(str+len, "%04x", key->exponent);
len += strlen(str+len);
str[len++] = '/';
for (i=1; i<key->bytes; i++) {
sprintf(str+len, "%02x", key->modulus[i]);
len += strlen(str+len);
}
str[len] = '\0';
}
/* ---------------------------------------------------------*
* DES encryption / decryption functions *
* ---------------------------------------------------------*/
void des3_sesskey(unsigned char *key) {
int i, j;
for(i = 0; i < 2; i++) {
for(j = 0; j < 3; j++) {
hDESKey[i][j] = create_des_key(key + (j * 8));
}
}
}
void des3_encrypt_blk(unsigned char *blk, int len) {
DWORD dlen;
dlen = len;
if(CryptEncrypt(hDESKey[0][0], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
fatalbox("Error encrypting block!\n");
if(CryptDecrypt(hDESKey[0][1], 0, FALSE, 0, blk, &dlen) == 0)
fatalbox("Error encrypting block!\n");
if(CryptEncrypt(hDESKey[0][2], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
fatalbox("Error encrypting block!\n");
}
void des3_decrypt_blk(unsigned char *blk, int len) {
DWORD dlen;
dlen = len;
if(CryptDecrypt(hDESKey[1][2], 0, FALSE, 0, blk, &dlen) == 0)
fatalbox("Error decrypting block!\n");
if(CryptEncrypt(hDESKey[1][1], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
fatalbox("Error decrypting block!\n");
if(CryptDecrypt(hDESKey[1][0], 0, FALSE, 0, blk, &dlen) == 0)
fatalbox("Error decrypting block!\n");
}
struct ssh_cipher ssh_3des = {
des3_sesskey,
des3_encrypt_blk,
des3_decrypt_blk
};
void des_sesskey(unsigned char *key) {
int i;
for(i = 0; i < 2; i++) {
hDESKey[i][0] = create_des_key(key);
}
}
void des_encrypt_blk(unsigned char *blk, int len) {
DWORD dlen;
dlen = len;
if(CryptEncrypt(hDESKey[0][0], 0, FALSE, 0, blk, &dlen, len + 8) == 0)
fatalbox("Error encrypting block!\n");
}
void des_decrypt_blk(unsigned char *blk, int len) {
DWORD dlen;
dlen = len;
if(CryptDecrypt(hDESKey[1][0], 0, FALSE, 0, blk, &dlen) == 0)
fatalbox("Error decrypting block!\n");
}
struct ssh_cipher ssh_des = {
des_sesskey,
des_encrypt_blk,
des_decrypt_blk
};
static HCRYPTKEY create_des_key(unsigned char *key) {
HCRYPTKEY hSessionKey, hPrivateKey;
DWORD dlen = 8;
BLOBHEADER *pbh;
char buf[sizeof(BLOBHEADER) + sizeof(ALG_ID) + 256];
/*
* Need special private key to encrypt session key so we can
* import session key, since only encrypted session keys can be
* imported
*/
if(CryptImportKey(hCryptProv, PrivateKeyWithExponentOfOne,
sizeof(PrivateKeyWithExponentOfOne),
0, 0, &hPrivateKey) == 0)
return 0;
/* now encrypt session key using special private key */
memcpy(buf + sizeof(BLOBHEADER) + sizeof(ALG_ID), key, 8);
if(CryptEncrypt(hPrivateKey, 0, TRUE, 0,
buf + sizeof(BLOBHEADER) + sizeof(ALG_ID),
&dlen, 256) == 0)
return 0;
/* build session key blob */
pbh = (BLOBHEADER*)buf;
pbh->bType = SIMPLEBLOB;
pbh->bVersion = 0x02;
pbh->reserved = 0;
pbh->aiKeyAlg = CALG_DES;
*((ALG_ID*)(buf+sizeof(BLOBHEADER))) = CALG_RSA_KEYX;
/* import session key into key container */
if(CryptImportKey(hCryptProv, buf,
dlen + sizeof(BLOBHEADER) + sizeof(ALG_ID),
hPrivateKey, 0, &hSessionKey) == 0)
return 0;
if(hPrivateKey)
CryptDestroyKey(hPrivateKey);
return hSessionKey;
}