text: /**
   * FreeRDP: A Remote Desktop Protocol Implementation
   * Cryptographic Abstraction Layer
   *
   * Copyright 2011-2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *	 http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #include <winpr/crt.h>
  
  #include <freerdp/utils/debug.h>
  #include <freerdp/crypto/crypto.h>
  
  CryptoSha1 crypto_sha1_init(void)
  {
  	CryptoSha1 sha1 = malloc(sizeof(*sha1));
  	if (!sha1)
  		return NULL;
  	SHA1_Init(&sha1->sha_ctx);
  	return sha1;
  }
  
  void crypto_sha1_update(CryptoSha1 sha1, const BYTE* data, UINT32 length)
  {
  	SHA1_Update(&sha1->sha_ctx, data, length);
  }
  
  void crypto_sha1_final(CryptoSha1 sha1, BYTE* out_data)
  {
  	SHA1_Final(out_data, &sha1->sha_ctx);
  	free(sha1);
  }
  
  CryptoMd5 crypto_md5_init(void)
  {
  	CryptoMd5 md5 = malloc(sizeof(*md5));
  	if (!md5)
  		return NULL;
  	MD5_Init(&md5->md5_ctx);
  	return md5;
  }
  
  void crypto_md5_update(CryptoMd5 md5, const BYTE* data, UINT32 length)
  {
  	MD5_Update(&md5->md5_ctx, data, length);
  }
  
  void crypto_md5_final(CryptoMd5 md5, BYTE* out_data)
  {
  	MD5_Final(out_data, &md5->md5_ctx);
  	free(md5);
  }
  
  CryptoRc4 crypto_rc4_init(const BYTE* key, UINT32 length)
  {
  	CryptoRc4 rc4 = malloc(sizeof(*rc4));
  	if (!rc4)
  		return NULL;
  	RC4_set_key(&rc4->rc4_key, length, key);
  	return rc4;
  }
  
  void crypto_rc4(CryptoRc4 rc4, UINT32 length, const BYTE* in_data, BYTE* out_data)
  {
  	RC4(&rc4->rc4_key, length, in_data, out_data);
  }
  
  void crypto_rc4_free(CryptoRc4 rc4)
  {
  	if (rc4)
  		free(rc4);
  }
  
  CryptoDes3 crypto_des3_encrypt_init(const BYTE* key, const BYTE* ivec)
  {
  	CryptoDes3 des3 = malloc(sizeof(*des3));
  	if (!des3)
  		return NULL;
  
  	EVP_CIPHER_CTX_init(&des3->des3_ctx);
  	EVP_EncryptInit_ex(&des3->des3_ctx, EVP_des_ede3_cbc(), NULL, key, ivec);
  	EVP_CIPHER_CTX_set_padding(&des3->des3_ctx, 0);
  	return des3;
  }
  
  CryptoDes3 crypto_des3_decrypt_init(const BYTE* key, const BYTE* ivec)
  {
  	CryptoDes3 des3 = malloc(sizeof(*des3));
  	if (!des3)
  		return NULL;
  
  	EVP_CIPHER_CTX_init(&des3->des3_ctx);
  	EVP_DecryptInit_ex(&des3->des3_ctx, EVP_des_ede3_cbc(), NULL, key, ivec);
  	EVP_CIPHER_CTX_set_padding(&des3->des3_ctx, 0);
  	return des3;
  }
  
  void crypto_des3_encrypt(CryptoDes3 des3, UINT32 length, const BYTE* in_data, BYTE* out_data)
  {
  	int len;
  	EVP_EncryptUpdate(&des3->des3_ctx, out_data, &len, in_data, length);
  }
  
  void crypto_des3_decrypt(CryptoDes3 des3, UINT32 length, const BYTE* in_data, BYTE* out_data)
  {
  	int len;
  	EVP_DecryptUpdate(&des3->des3_ctx, out_data, &len, in_data, length);
  
  	if (length != len)
  		abort(); /* TODO */
  }
  
  void crypto_des3_free(CryptoDes3 des3)
  {
  	if (des3 == NULL)
  		return;
  	EVP_CIPHER_CTX_cleanup(&des3->des3_ctx);
  	free(des3);
  }
  
  CryptoHmac crypto_hmac_new(void)
  {
  	CryptoHmac hmac = malloc(sizeof(*hmac));
  	if (!hmac)
  		return NULL;
  
  	HMAC_CTX_init(&hmac->hmac_ctx);
  	return hmac;
  }
  
  void crypto_hmac_sha1_init(CryptoHmac hmac, const BYTE* data, UINT32 length)
  {
  	HMAC_Init_ex(&hmac->hmac_ctx, data, length, EVP_sha1(), NULL);
  }
  
  void crypto_hmac_md5_init(CryptoHmac hmac, const BYTE* data, UINT32 length)
  {
  	HMAC_Init_ex(&hmac->hmac_ctx, data, length, EVP_md5(), NULL);
  }
  
  void crypto_hmac_update(CryptoHmac hmac, const BYTE* data, UINT32 length)
  {
  	HMAC_Update(&hmac->hmac_ctx, data, length);
  }
  
  void crypto_hmac_final(CryptoHmac hmac, BYTE* out_data, UINT32 length)
  {
  	HMAC_Final(&hmac->hmac_ctx, out_data, &length);
  }
  
  void crypto_hmac_free(CryptoHmac hmac)
  {
  	if (hmac == NULL)
  		return;
  
  	HMAC_CTX_cleanup(&hmac->hmac_ctx);
  	free(hmac);
  }
  
  CryptoCert crypto_cert_read(BYTE* data, UINT32 length)
  {
  	CryptoCert cert = malloc(sizeof(*cert));
  	if (!cert)
  		return NULL;
  
  	/* this will move the data pointer but we don't care, we don't use it again */
  	cert->px509 = d2i_X509(NULL, (D2I_X509_CONST BYTE **) &data, length);
  	return cert;
  }
  
  void crypto_cert_free(CryptoCert cert)
  {
  	if (cert == NULL)
  		return;
  
  	X509_free(cert->px509);
  
  	free(cert);
  }
  
  BOOL crypto_cert_get_public_key(CryptoCert cert, BYTE** PublicKey, DWORD* PublicKeyLength)
  {
  	BYTE* ptr;
  	int length;
  	BOOL status = TRUE;
  	EVP_PKEY* pkey = NULL;
  
  	pkey = X509_get_pubkey(cert->px509);
  	if (!pkey)
  	{
  		DEBUG_WARN( "%s: X509_get_pubkey() failed\n", __FUNCTION__);
  		status = FALSE;
  		goto exit;
  	}
  
  	length = i2d_PublicKey(pkey, NULL);
  	if (length < 1)
  	{
  		DEBUG_WARN( "%s: i2d_PublicKey() failed\n", __FUNCTION__);
  		status = FALSE;
  		goto exit;
  	}
  
  	*PublicKeyLength = (DWORD) length;
  	*PublicKey = (BYTE*) malloc(length);
  	ptr = (BYTE*) (*PublicKey);
  
  	i2d_PublicKey(pkey, &ptr);
  
  exit:
  	if (pkey)
  		EVP_PKEY_free(pkey);
  
  	return status;
  }
  
  static int crypto_rsa_common(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* exponent, int exponent_size, BYTE* output)
  {
  	BN_CTX* ctx;
  	int output_length = -1;
  	BYTE* input_reverse;
  	BYTE* modulus_reverse;
  	BYTE* exponent_reverse;
  	BIGNUM mod, exp, x, y;
  
  	input_reverse = (BYTE*) malloc(2 * key_length + exponent_size);
  	if (!input_reverse)
  		return -1;
  	modulus_reverse = input_reverse + key_length;
  	exponent_reverse = modulus_reverse + key_length;
  
  	memcpy(modulus_reverse, modulus, key_length);
  	crypto_reverse(modulus_reverse, key_length);
  	memcpy(exponent_reverse, exponent, exponent_size);
  	crypto_reverse(exponent_reverse, exponent_size);
  	memcpy(input_reverse, input, length);
  	crypto_reverse(input_reverse, length);
  
  	ctx = BN_CTX_new();
  	if (!ctx)
  		goto out_free_input_reverse;
  	BN_init(&mod);
  	BN_init(&exp);
  	BN_init(&x);
  	BN_init(&y);
  
  	BN_bin2bn(modulus_reverse, key_length, &mod);
  	BN_bin2bn(exponent_reverse, exponent_size, &exp);
  	BN_bin2bn(input_reverse, length, &x);
  	BN_mod_exp(&y, &x, &exp, &mod, ctx);
  
  	output_length = BN_bn2bin(&y, output);
  	crypto_reverse(output, output_length);
  
  	if (output_length < (int) key_length)
  		memset(output + output_length, 0, key_length - output_length);
  
  	BN_free(&y);
  	BN_clear_free(&x);
  	BN_free(&exp);
  	BN_free(&mod);
  	BN_CTX_free(ctx);
  
  out_free_input_reverse:
  	free(input_reverse);
  
  	return output_length;
  }
  
  static int crypto_rsa_public(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* exponent, BYTE* output)
  {
  	return crypto_rsa_common(input, length, key_length, modulus, exponent, EXPONENT_MAX_SIZE, output);
  }
  
  static int crypto_rsa_private(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* private_exponent, BYTE* output)
  {
  	return crypto_rsa_common(input, length, key_length, modulus, private_exponent, key_length, output);
  }
  
  int crypto_rsa_public_encrypt(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* exponent, BYTE* output)
  {
  	return crypto_rsa_public(input, length, key_length, modulus, exponent, output);
  }
  
  int crypto_rsa_public_decrypt(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* exponent, BYTE* output)
  {
  	return crypto_rsa_public(input, length, key_length, modulus, exponent, output);
  }
  
  int crypto_rsa_private_encrypt(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* private_exponent, BYTE* output)
  {
  	return crypto_rsa_private(input, length, key_length, modulus, private_exponent, output);
  }
  
  int crypto_rsa_private_decrypt(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* private_exponent, BYTE* output)
  {
  	return crypto_rsa_private(input, length, key_length, modulus, private_exponent, output);
  }
  
  int crypto_rsa_decrypt(const BYTE* input, int length, UINT32 key_length, const BYTE* modulus, const BYTE* private_exponent, BYTE* output)
  {
  	return crypto_rsa_common(input, length, key_length, modulus, private_exponent, key_length, output);
  }
  
  void crypto_reverse(BYTE* data, int length)
  {
  	int i, j;
  	BYTE temp;
  
  	for (i = 0, j = length - 1; i < j; i++, j--)
  	{
  		temp = data[i];
  		data[i] = data[j];
  		data[j] = temp;
  	}
  }
  
  void crypto_nonce(BYTE* nonce, int size)
  {
  	RAND_bytes((void*) nonce, size);
  }
  
  char* crypto_cert_fingerprint(X509* xcert)
  {
  	int i = 0;
  	char* p;
  	char* fp_buffer;
  	UINT32 fp_len;
  	BYTE fp[EVP_MAX_MD_SIZE];
  
  	X509_digest(xcert, EVP_sha1(), fp, &fp_len);
  
  	fp_buffer = (char*) calloc(3, fp_len);
  	if (!fp_buffer)
  		return NULL;
  
  	p = fp_buffer;
  	for (i = 0; i < (int) (fp_len - 1); i++)
  	{
  		sprintf(p, "%02x:", fp[i]);
  		p = &fp_buffer[(i + 1) * 3];
  	}
  	sprintf(p, "%02x", fp[i]);
  
  	return fp_buffer;
  }
  
  char* crypto_print_name(X509_NAME* name)
  {
  	char* buffer = NULL;
  	BIO* outBIO = BIO_new(BIO_s_mem());
  	
  	if (X509_NAME_print_ex(outBIO, name, 0, XN_FLAG_ONELINE) > 0)
  	{
  		unsigned long size = BIO_number_written(outBIO);
  		buffer = malloc(size + 1);
  		ZeroMemory(buffer, size + 1);
  		memset(buffer, 0, size + 1);
  		BIO_read(outBIO, buffer, size);
  	}
  
  	BIO_free(outBIO);
  
  	return buffer;
  }
  
  char* crypto_cert_subject(X509* xcert)
  {
  	return crypto_print_name(X509_get_subject_name(xcert));
  }
  
  char* crypto_cert_subject_common_name(X509* xcert, int* length)
  {
  	int index;
  	BYTE* common_name;
  	X509_NAME* subject_name;
  	X509_NAME_ENTRY* entry;
  	ASN1_STRING* entry_data;
  
  	subject_name = X509_get_subject_name(xcert);
  
  	if (subject_name == NULL)
  		return NULL;
  
  	index = X509_NAME_get_index_by_NID(subject_name, NID_commonName, -1);
  
  	if (index < 0)
  		return NULL;
  
  	entry = X509_NAME_get_entry(subject_name, index);
  
  	if (entry == NULL)
  		return NULL;
  
  	entry_data = X509_NAME_ENTRY_get_data(entry);
  
  	if (entry_data == NULL)
  		return NULL;
  
  	*length = ASN1_STRING_to_UTF8(&common_name, entry_data);
  
  	if (*length < 0)
  		return NULL;
  
  	return (char*) common_name;
  }
  
  FREERDP_API void crypto_cert_subject_alt_name_free(int count, int *lengths,
  		char** alt_name)
  {
  	int i;
  
  	if (lengths)
  		free(lengths);
  
  	if (alt_name)
  	{
  		for (i=0; i<count; i++)
  		{
  			if (alt_name[i])
  				OPENSSL_free(alt_name[i]);
  		}
  
  		free(alt_name);
  	}
  }
  
  char** crypto_cert_subject_alt_name(X509* xcert, int* count, int** lengths)
  {
  	int index;
  	int length = 0;
  	char** strings = NULL;
  	BYTE* string;
  	int num_subject_alt_names;
  	GENERAL_NAMES* subject_alt_names;
  	GENERAL_NAME* subject_alt_name;
  
  	*count = 0;
  	subject_alt_names = X509_get_ext_d2i(xcert, NID_subject_alt_name, 0, 0);
  
  	if (!subject_alt_names)
  		return NULL;
  
  	num_subject_alt_names = sk_GENERAL_NAME_num(subject_alt_names);
  	if (num_subject_alt_names)
  	{
  		strings = (char**) malloc(sizeof(char*) * num_subject_alt_names);
  		*lengths = (int*) malloc(sizeof(int) * num_subject_alt_names);
  	}
  
  	for (index = 0; index < num_subject_alt_names; ++index)
  	{
  		subject_alt_name = sk_GENERAL_NAME_value(subject_alt_names, index);
  
  		if (subject_alt_name->type == GEN_DNS)
  		{
  			length = ASN1_STRING_to_UTF8(&string, subject_alt_name->d.dNSName);
  			strings[*count] = (char*) string;
  			(*lengths)[*count] = length;
  			(*count)++;
  		}
  	}
  
  	if (*count < 1)
  	{
  		free(strings) ;
  		free(*lengths) ;
  		*lengths = NULL ;
  		return NULL;
  	}
  	GENERAL_NAMES_free(subject_alt_names);
  
  	return strings;
  }
  
  char* crypto_cert_issuer(X509* xcert)
  {
  	return crypto_print_name(X509_get_issuer_name(xcert));
  }
  
  BOOL x509_verify_certificate(CryptoCert cert, char* certificate_store_path)
  {
  	X509_STORE_CTX* csc;
  	BOOL status = FALSE;
  	X509_STORE* cert_ctx = NULL;
  	X509_LOOKUP* lookup = NULL;
  	X509* xcert = cert->px509;
  
  	cert_ctx = X509_STORE_new();
  
  	if (cert_ctx == NULL)
  		goto end;
  
  	OpenSSL_add_all_algorithms();
  	lookup = X509_STORE_add_lookup(cert_ctx, X509_LOOKUP_file());
  
  	if (lookup == NULL)
  		goto end;
  
  	lookup = X509_STORE_add_lookup(cert_ctx, X509_LOOKUP_hash_dir());
  
  	if (lookup == NULL)
  		goto end;
  
  	X509_LOOKUP_add_dir(lookup, NULL, X509_FILETYPE_DEFAULT);
  
  	if (certificate_store_path != NULL)
  	{
  		X509_LOOKUP_add_dir(lookup, certificate_store_path, X509_FILETYPE_ASN1);
  	}
  
  	csc = X509_STORE_CTX_new();
  
  	if (csc == NULL)
  		goto end;
  
  	X509_STORE_set_flags(cert_ctx, 0);
  
  	if (!X509_STORE_CTX_init(csc, cert_ctx, xcert, 0))
  		goto end;
  
  	if (X509_verify_cert(csc) == 1)
  		status = TRUE;
  
  	X509_STORE_CTX_free(csc);
  	X509_STORE_free(cert_ctx);
  
  end:
  	return status;
  }
  
  rdpCertificateData* crypto_get_certificate_data(X509* xcert, char* hostname)
  {
  	char* fp;
  	rdpCertificateData* certdata;
  
  	fp = crypto_cert_fingerprint(xcert);
  	if (!fp)
  		return NULL;
  
  	certdata = certificate_data_new(hostname, fp);
  	free(fp);
  
  	return certdata;
  }
  
  void crypto_cert_print_info(X509* xcert)
  {
  	char* fp;
  	char* issuer;
  	char* subject;
  
  	subject = crypto_cert_subject(xcert);
  	issuer = crypto_cert_issuer(xcert);
  	fp = crypto_cert_fingerprint(xcert);
  	if (!fp)
  	{
  		DEBUG_WARN( "%s: error computing fingerprint\n", __FUNCTION__);
  		goto out_free_issuer;
  	}
  
  	DEBUG_WARN( "Certificate details:\n");
  	DEBUG_WARN( "\tSubject: %s\n", subject);
  	DEBUG_WARN( "\tIssuer: %s\n", issuer);
  	DEBUG_WARN( "\tThumbprint: %s\n", fp);
  	DEBUG_WARN( "The above X.509 certificate could not be verified, possibly because you do not have "
  			"the CA certificate in your certificate store, or the certificate has expired. "
  			"Please look at the documentation on how to create local certificate store for a private CA.\n");
  
  	free(fp);
  out_free_issuer:
  	free(issuer);
  	free(subject);
  }
  