FreeRDP/libfreerdp/crypto/crypto.c
Hardening ac7507ab8d Adds some check to treat OOM problems + RDP security fix
Malloc can fail so it will, this patch adds some check in some places
where malloc/strdup results were not checked.

This patch also contains a server side fix for RDP security (credit to nfedera).
The signature len was badly set in the GCC packet. And some other RDP security
oriented fixes are also there.
2014-03-25 23:13:08 +01:00

589 lines
13 KiB
C

/**
* 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/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)
{
fprintf(stderr, "%s: X509_get_pubkey() failed\n", __FUNCTION__);
status = FALSE;
goto exit;
}
length = i2d_PublicKey(pkey, NULL);
if (length < 1)
{
fprintf(stderr, "%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)
{
fprintf(stderr, "%s: error computing fingerprint\n", __FUNCTION__);
goto out_free_issuer;
}
fprintf(stderr, "Certificate details:\n");
fprintf(stderr, "\tSubject: %s\n", subject);
fprintf(stderr, "\tIssuer: %s\n", issuer);
fprintf(stderr, "\tThumbprint: %s\n", fp);
fprintf(stderr, "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);
}