diff options
Diffstat (limited to 'src/cipher.c')
| -rw-r--r-- | src/cipher.c | 103 |
1 files changed, 60 insertions, 43 deletions
diff --git a/src/cipher.c b/src/cipher.c index f640d6d..f1a4bf4 100644 --- a/src/cipher.c +++ b/src/cipher.c @@ -106,12 +106,12 @@ void cipher_close(cipher_t* c) } -void cipher_encrypt(cipher_t* c, key_derivation_t* kd, plain_packet_t* in, encrypted_packet_t* out, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) +int cipher_encrypt(cipher_t* c, key_derivation_t* kd, plain_packet_t* in, encrypted_packet_t* out, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) { if(!c) - return; + return -1; - u_int32_t len; + int32_t len; if(c->type_ == c_null) len = cipher_null_crypt(plain_packet_get_packet(in), plain_packet_get_length(in), encrypted_packet_get_payload(out), encrypted_packet_get_payload_length(out)); @@ -121,22 +121,27 @@ void cipher_encrypt(cipher_t* c, key_derivation_t* kd, plain_packet_t* in, encry seq_nr, sender_id, mux); else { log_printf(ERR, "unknown cipher type"); - return; + return -1; } + if(len < 0) + return 0; + encrypted_packet_set_sender_id(out, sender_id); encrypted_packet_set_seq_nr(out, seq_nr); encrypted_packet_set_mux(out, mux); encrypted_packet_set_payload_length(out, len); + + return 0; } -void cipher_decrypt(cipher_t* c, key_derivation_t* kd, encrypted_packet_t* in, plain_packet_t* out) +int cipher_decrypt(cipher_t* c, key_derivation_t* kd, encrypted_packet_t* in, plain_packet_t* out) { if(!c) - return; + return -1; - u_int32_t len; + int32_t len; if(c->type_ == c_null) len = cipher_null_crypt(encrypted_packet_get_payload(in), encrypted_packet_get_payload_length(in), plain_packet_get_packet(out), plain_packet_get_length(out)); @@ -147,15 +152,20 @@ void cipher_decrypt(cipher_t* c, key_derivation_t* kd, encrypted_packet_t* in, p encrypted_packet_get_mux(in)); else { log_printf(ERR, "unknown cipher type"); - return; + return -1; } + if(len < 0) + return 0; + plain_packet_set_length(out, len); + + return 0; } /* ---------------- NULL Cipher ---------------- */ -u_int32_t cipher_null_crypt(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen) +int32_t cipher_null_crypt(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen) { memcpy(out, in, (ilen < olen) ? ilen : olen); return (ilen < olen) ? ilen : olen; @@ -168,6 +178,22 @@ int cipher_aesctr_init(cipher_t* c) if(!c) return -1; + if(c->key_.buf_) + free(c->key_.buf_); + + c->key_.length_ = c->key_length_/8; + c->key_.buf_ = malloc(c->key_.length_); + if(!c->key_.buf_) + return -2; + + if(c->salt_.buf_) + free(c->salt_.buf_); + + c->salt_.length_ = 14; + c->salt_.buf_ = malloc(c->salt_.length_); + if(!c->salt_.buf_) + return -2; + int algo; switch(c->key_length_) { case 128: algo = GCRY_CIPHER_AES128; break; @@ -179,7 +205,7 @@ int cipher_aesctr_init(cipher_t* c) } } - gcry_error_t err = gcry_cipher_open( &c->handle_, algo, GCRY_CIPHER_MODE_CTR, 0 ); + gcry_error_t err = gcry_cipher_open(&c->handle_, algo, GCRY_CIPHER_MODE_CTR, 0); if(err) { log_printf(ERR, "failed to open cipher: %s/%s", gcry_strerror(err), gcry_strsource(err)); return -1; @@ -206,14 +232,6 @@ buffer_t cipher_aesctr_calc_ctr(cipher_t* c, key_derivation_t* kd, seq_nr_t seq_ if(!c) return result; - if(!c->salt_.buf_) { - c->salt_.length_ = 14; - c->salt_.buf_ = malloc(c->salt_.length_); - if(!c->salt_.buf_) { - log_printf(ERR, "memory error aes-ctr calc ctr"); - return result; - } - } int ret = key_derivation_generate(kd, LABEL_SATP_SALT, seq_nr, c->salt_.buf_, c->salt_.length_); if(ret < 0) return result; @@ -259,54 +277,53 @@ buffer_t cipher_aesctr_calc_ctr(cipher_t* c, key_derivation_t* kd, seq_nr_t seq_ return result; } -u_int32_t cipher_aesctr_crypt(cipher_t* c, key_derivation_t* kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) +int32_t cipher_aesctr_crypt(cipher_t* c, key_derivation_t* kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) { - if(!c) { - log_printf(ERR, "cipher not initialized"); - return 0; - } + if(!c) + return -1; + if(!kd) { log_printf(ERR, "no key derivation supplied"); - return 0; - } - - - if(!c->key_.buf_) { - c->key_.length_ = c->key_length_/8; - c->key_.buf_ = malloc(c->key_.length_); - if(!c->key_.buf_) { - log_printf(ERR, "memory error aes-ctr crypt"); - return 0; - } + return -1; } int ret = key_derivation_generate(kd, LABEL_SATP_ENCRYPTION, seq_nr, c->key_.buf_, c->key_.length_); if(ret < 0) - return 0; + return ret; - gcry_error_t err = gcry_cipher_setkey(c->handle_, c->key_.buf_, c->key_.length_); - if(err) { - log_printf(ERR, "failed to set cipher key: %s/%s", gcry_strerror(err), gcry_strsource(err)); - return 0; + gcry_error_t err; + if(ret) { // a new key got generated + err = gcry_cipher_setkey(c->handle_, c->key_.buf_, c->key_.length_); + if(err) { + log_printf(ERR, "failed to set cipher key: %s/%s", gcry_strerror(err), gcry_strsource(err)); + return -1; + } + } // no new key got generated + else { + err = gcry_cipher_reset(c->handle_); + if(err) { + log_printf(ERR, "failed to reset cipher: %s/%s", gcry_strerror(err), gcry_strsource(err)); + return -1; + } } buffer_t ctr = cipher_aesctr_calc_ctr(c, kd, seq_nr, sender_id, mux); if(!ctr.buf_) { log_printf(ERR, "failed to calculate cipher CTR"); - return 0; + return -1; } err = gcry_cipher_setctr(c->handle_, ctr.buf_, ctr.length_); free(ctr.buf_); if(err) { log_printf(ERR, "failed to set cipher CTR: %s/%s", gcry_strerror(err), gcry_strsource(err)); - return 0; + return -1; } err = gcry_cipher_encrypt(c->handle_, out, olen, in, ilen); if(err) { - log_printf(ERR, "failed to generate cipher bitstream: %s/%s", gcry_strerror(err), gcry_strsource(err)); - return 0; + log_printf(ERR, "failed to de/encrypt packet: %s/%s", gcry_strerror(err), gcry_strsource(err)); + return -1; } return (ilen < olen) ? ilen : olen; |