Branch data     Line data    Source code

       1                 :            : /*
       2                 :            :  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
       3                 :            :  *
       4                 :            :  * Licensed under the Apache License, Version 2.0 (the "License").
       5                 :            :  * You may not use this file except in compliance with the License.
       6                 :            :  * A copy of the License is located at
       7                 :            :  *
       8                 :            :  *  http://aws.amazon.com/apache2.0
       9                 :            :  *
      10                 :            :  * or in the "license" file accompanying this file. This file is distributed
      11                 :            :  * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
      12                 :            :  * express or implied. See the License for the specific language governing
      13                 :            :  * permissions and limitations under the License.
      14                 :            :  */
      15                 :            : 
      16                 :            : #include <openssl/rc4.h>
      17                 :            : 
      18                 :            : #include "crypto/s2n_cipher.h"
      19                 :            : #include "crypto/s2n_fips.h"
      20                 :            : #include "crypto/s2n_openssl.h"
      21                 :            : #include "utils/s2n_blob.h"
      22                 :            : #include "utils/s2n_safety.h"
      23                 :            : 
      24                 :            : static const EVP_CIPHER *s2n_evp_rc4()
      25                 :          2 : {
      26                 :          2 : #ifdef S2N_LIBCRYPTO_SUPPORTS_EVP_RC4
      27                 :          2 :     return EVP_rc4();
      28                 :            : #else
      29                 :            :     return NULL;
      30                 :            : #endif
      31                 :          2 : }
      32                 :            : 
      33                 :            : static bool s2n_stream_cipher_rc4_available(void)
      34                 :       3275 : {
      35                 :            :     /* RC4 MIGHT be available in Openssl-3.0, depending on whether or not the
      36                 :            :      * "legacy" provider is loaded. However, for simplicity, assume that RC4
      37                 :            :      * is unavailable.
      38                 :            :      */
      39                 :       3275 :     if (S2N_OPENSSL_VERSION_AT_LEAST(3, 0, 0)) {
      40                 :       3275 :         return false;
      41                 :       3275 :     }
      42         [ #  # ]:          0 :     return (s2n_evp_rc4() ? true : false);
      43                 :       3275 : }
      44                 :            : 
      45                 :            : static int s2n_stream_cipher_rc4_encrypt(struct s2n_session_key *key, struct s2n_blob *in, struct s2n_blob *out)
      46                 :          0 : {
      47 [ #  # ][ #  # ]:          0 :     POSIX_ENSURE_GTE(out->size, in->size);
      48                 :            : 
      49                 :            :     /* len is set by EVP_EncryptUpdate and checked post operation */
      50                 :          0 :     int len = 0;
      51 [ #  # ][ #  # ]:          0 :     POSIX_GUARD_OSSL(EVP_EncryptUpdate(key->evp_cipher_ctx, out->data, &len, in->data, in->size), S2N_ERR_ENCRYPT);
      52                 :            : 
      53 [ #  # ][ #  # ]:          0 :     POSIX_ENSURE((int64_t) len == (int64_t) in->size, S2N_ERR_DECRYPT);
      54                 :            : 
      55                 :          0 :     return 0;
      56                 :          0 : }
      57                 :            : 
      58                 :            : static int s2n_stream_cipher_rc4_decrypt(struct s2n_session_key *key, struct s2n_blob *in, struct s2n_blob *out)
      59                 :          0 : {
      60 [ #  # ][ #  # ]:          0 :     POSIX_ENSURE_GTE(out->size, in->size);
      61                 :            : 
      62                 :            :     /* len is set by EVP_DecryptUpdate and checked post operation */
      63                 :          0 :     int len = 0;
      64 [ #  # ][ #  # ]:          0 :     POSIX_GUARD_OSSL(EVP_DecryptUpdate(key->evp_cipher_ctx, out->data, &len, in->data, in->size), S2N_ERR_DECRYPT);
      65                 :            : 
      66 [ #  # ][ #  # ]:          0 :     POSIX_ENSURE((int64_t) len == (int64_t) in->size, S2N_ERR_DECRYPT);
      67                 :            : 
      68                 :          0 :     return 0;
      69                 :          0 : }
      70                 :            : 
      71                 :            : static S2N_RESULT s2n_stream_cipher_rc4_set_encryption_key(struct s2n_session_key *key, struct s2n_blob *in)
      72                 :          1 : {
      73 [ -  + ][ #  # ]:          1 :     RESULT_ENSURE_EQ(in->size, 16);
      74 [ +  - ][ +  - ]:          1 :     RESULT_GUARD_OSSL(EVP_EncryptInit_ex(key->evp_cipher_ctx, s2n_evp_rc4(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
      75                 :            : 
      76                 :          0 :     return S2N_RESULT_OK;
      77                 :          1 : }
      78                 :            : 
      79                 :            : static S2N_RESULT s2n_stream_cipher_rc4_set_decryption_key(struct s2n_session_key *key, struct s2n_blob *in)
      80                 :          1 : {
      81 [ -  + ][ #  # ]:          1 :     RESULT_ENSURE_EQ(in->size, 16);
      82 [ +  - ][ +  - ]:          1 :     RESULT_GUARD_OSSL(EVP_DecryptInit_ex(key->evp_cipher_ctx, s2n_evp_rc4(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
      83                 :            : 
      84                 :          0 :     return S2N_RESULT_OK;
      85                 :          1 : }
      86                 :            : 
      87                 :            : static S2N_RESULT s2n_stream_cipher_rc4_init(struct s2n_session_key *key)
      88                 :          2 : {
      89 [ #  # ][ -  + ]:          2 :     RESULT_EVP_CTX_INIT(key->evp_cipher_ctx);
      90                 :            : 
      91                 :          2 :     return S2N_RESULT_OK;
      92                 :          2 : }
      93                 :            : 
      94                 :            : static S2N_RESULT s2n_stream_cipher_rc4_destroy_key(struct s2n_session_key *key)
      95                 :          0 : {
      96                 :          0 :     EVP_CIPHER_CTX_cleanup(key->evp_cipher_ctx);
      97                 :            : 
      98                 :          0 :     return S2N_RESULT_OK;
      99                 :          0 : }
     100                 :            : 
     101                 :            : const struct s2n_cipher s2n_rc4 = {
     102                 :            :     .type = S2N_STREAM,
     103                 :            :     .key_material_size = 16,
     104                 :            :     .io.stream = {
     105                 :            :             .decrypt = s2n_stream_cipher_rc4_decrypt,
     106                 :            :             .encrypt = s2n_stream_cipher_rc4_encrypt },
     107                 :            :     .is_available = s2n_stream_cipher_rc4_available,
     108                 :            :     .init = s2n_stream_cipher_rc4_init,
     109                 :            :     .set_decryption_key = s2n_stream_cipher_rc4_set_decryption_key,
     110                 :            :     .set_encryption_key = s2n_stream_cipher_rc4_set_encryption_key,
     111                 :            :     .destroy_key = s2n_stream_cipher_rc4_destroy_key,
     112                 :            : };