SSL AEAD support.
This change allows AEADs to be used in ssl/ to implement SSL/TLS
ciphersuites.
diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
index ee54dfd..5fde29d 100644
--- a/ssl/s3_enc.c
+++ b/ssl/s3_enc.c
@@ -371,7 +371,13 @@
if (s->s3->tmp.key_block_length != 0)
return(1);
- if (!ssl_cipher_get_evp(s->session,&c,&hash,NULL,NULL,&comp))
+ if (!ssl_cipher_get_comp(s->session, &comp))
+ {
+ OPENSSL_PUT_ERROR(SSL, ssl3_setup_key_block, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
+ return(0);
+ }
+
+ if (!ssl_cipher_get_evp(s->session,&c,&hash,NULL,NULL))
{
OPENSSL_PUT_ERROR(SSL, ssl3_setup_key_block, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
return(0);
diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index 172573f..c244724 100644
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -765,7 +765,9 @@
else
eivlen = 0;
}
- else
+ else if (s->aead_write_ctx != NULL)
+ eivlen = s->aead_write_ctx->variable_nonce_len;
+ else
eivlen = 0;
/* lets setup the record stuff. */
diff --git a/ssl/ssl.h b/ssl/ssl.h
index c030806..5c0626c 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -438,7 +438,9 @@
unsigned long algorithm_ssl; /* (major) protocol version */
unsigned long algo_strength; /* strength and export flags */
- unsigned long algorithm2; /* Extra flags */
+ unsigned long algorithm2; /* Extra flags. See SSL2_CF_* in ssl2.h
+ and algorithm2 section in
+ ssl_locl.h */
int strength_bits; /* Number of bits really used */
int alg_bits; /* Number of bits for algorithm */
};
@@ -825,6 +827,9 @@
#define SSL_set_msg_callback_arg(ssl, arg) SSL_ctrl((ssl), SSL_CTRL_SET_MSG_CALLBACK_ARG, 0, (arg))
+struct ssl_aead_ctx_st;
+typedef struct ssl_aead_ctx_st SSL_AEAD_CTX;
+
#if defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32)
#define SSL_MAX_CERT_LIST_DEFAULT 1024*30 /* 30k max cert list :-) */
#else
@@ -1404,10 +1409,16 @@
/* These are the ones being used, the ones in SSL_SESSION are
* the ones to be 'copied' into these ones */
int mac_flags;
+ SSL_AEAD_CTX *aead_read_ctx; /* AEAD context. If non-NULL, then
+ |enc_read_ctx| and |read_hash| are
+ ignored. */
EVP_CIPHER_CTX *enc_read_ctx; /* cryptographic state */
EVP_MD_CTX *read_hash; /* used for mac generation */
char *expand;
+ SSL_AEAD_CTX *aead_write_ctx; /* AEAD context. If non-NULL, then
+ |enc_write_ctx| and |write_hash| are
+ ignored. */
EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
EVP_MD_CTX *write_hash; /* used for mac generation */
char *compress;
@@ -2658,6 +2669,8 @@
#define SSL_F_ssl3_send_channel_id 276
#define SSL_F_SSL_CTX_set_cipher_list_tls11 277
#define SSL_F_tls1_change_cipher_state_cipher 278
+#define SSL_F_tls1_change_cipher_state_aead 279
+#define SSL_F_tls1_aead_ctx_init 280
#define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 100
#define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 101
#define SSL_R_INVALID_NULL_CMD_NAME 102
diff --git a/ssl/ssl3.h b/ssl/ssl3.h
index 04d2e0c..43fc22d 100644
--- a/ssl/ssl3.h
+++ b/ssl/ssl3.h
@@ -529,6 +529,7 @@
unsigned char *key_block;
const EVP_CIPHER *new_sym_enc;
+ const EVP_AEAD *new_aead;
const EVP_MD *new_hash;
int new_mac_pkey_type;
int new_mac_secret_size;
diff --git a/ssl/ssl_ciph.c b/ssl/ssl_ciph.c
index aac6883..e235020 100644
--- a/ssl/ssl_ciph.c
+++ b/ssl/ssl_ciph.c
@@ -350,29 +350,62 @@
ssl_mac_secret_size[SSL_MD_SHA384_IDX]= EVP_MD_size(EVP_sha384());
}
-int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
- const EVP_MD **md, int *mac_pkey_type, int *mac_secret_size,SSL_COMP **comp)
+/* ssl_cipher_get_comp sets |comp| to the correct SSL_COMP for the given
+ * session and returns 1. On error it returns 0. */
+int ssl_cipher_get_comp(const SSL_SESSION *s, SSL_COMP **comp)
{
- size_t compression_index;
+ size_t index;
+
+ SSL_COMP ctmp;
+
+ *comp=NULL;
+ ctmp.id=s->compress_meth;
+ if (ssl_comp_methods != NULL)
+ {
+ if (sk_SSL_COMP_find(ssl_comp_methods, &index, &ctmp))
+ *comp=sk_SSL_COMP_value(ssl_comp_methods,index);
+ else
+ *comp=NULL;
+ }
+
+ return 1;
+ }
+
+/* ssl_cipher_get_evp_aead sets |*aead| to point to the correct EVP_AEAD object
+ * for |s->cipher|. It returns 1 on success and 0 on error. */
+int ssl_cipher_get_evp_aead(const SSL_SESSION *s, const EVP_AEAD **aead)
+ {
+ const SSL_CIPHER *c = s->cipher;
+
+ *aead = NULL;
+
+ if (c == NULL)
+ return 0;
+ if ((c->algorithm2 & SSL_CIPHER_ALGORITHM2_AEAD) == 0)
+ return 0;
+
+#ifndef OPENSSL_NO_AES
+ /* There is only one AEAD for now. */
+ *aead = EVP_aead_aes_128_gcm();
+ return 1;
+#endif
+
+ return 0;
+ }
+
+int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
+ const EVP_MD **md, int *mac_pkey_type, int *mac_secret_size)
+ {
int i;
const SSL_CIPHER *c;
c=s->cipher;
if (c == NULL) return(0);
- if (comp != NULL)
- {
- SSL_COMP ctmp;
- *comp=NULL;
- ctmp.id=s->compress_meth;
- if (ssl_comp_methods != NULL)
- {
- if (sk_SSL_COMP_find(ssl_comp_methods, &compression_index, &ctmp))
- *comp=sk_SSL_COMP_value(ssl_comp_methods, compression_index);
- else
- *comp=NULL;
- }
- }
+ /* This function doesn't deal with EVP_AEAD. See
+ * |ssl_cipher_get_aead_evp|. */
+ if (c->algorithm2 & SSL_CIPHER_ALGORITHM2_AEAD)
+ return(0);
if ((enc == NULL) || (md == NULL)) return(0);
diff --git a/ssl/ssl_error.c b/ssl/ssl_error.c
index 26fb4a2..76e2745 100644
--- a/ssl/ssl_error.c
+++ b/ssl/ssl_error.c
@@ -188,8 +188,10 @@
{ERR_PACK(ERR_LIB_SSL, SSL_F_ssl_verify_cert_chain, 0), "ssl_verify_cert_chain"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls12_check_peer_sigalg, 0), "tls12_check_peer_sigalg"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_PRF, 0), "tls1_PRF"},
+ {ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_aead_ctx_init, 0), "tls1_aead_ctx_init"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_cert_verify_mac, 0), "tls1_cert_verify_mac"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_change_cipher_state, 0), "tls1_change_cipher_state"},
+ {ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_change_cipher_state_aead, 0), "tls1_change_cipher_state_aead"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_change_cipher_state_cipher, 0), "tls1_change_cipher_state_cipher"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_export_keying_material, 0), "tls1_export_keying_material"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_get_server_supplemental_data, 0), "tls1_get_server_supplemental_data"},
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 8e326de..c0e463c 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -2914,6 +2914,18 @@
OPENSSL_free(s->enc_write_ctx);
s->enc_write_ctx=NULL;
}
+ if (s->aead_read_ctx != NULL)
+ {
+ EVP_AEAD_CTX_cleanup(&s->aead_read_ctx->ctx);
+ OPENSSL_free(s->aead_read_ctx);
+ s->aead_read_ctx = NULL;
+ }
+ if (s->aead_write_ctx != NULL)
+ {
+ EVP_AEAD_CTX_cleanup(&s->aead_write_ctx->ctx);
+ OPENSSL_free(s->aead_write_ctx);
+ s->aead_write_ctx = NULL;
+ }
}
X509 *SSL_get_certificate(const SSL *s)
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index fe2c7ea..22637a1 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -149,6 +149,7 @@
#include <string.h>
#include <time.h>
+#include <openssl/aead.h>
#include <openssl/bio.h>
#include <openssl/buf.h>
#include <openssl/dsa.h>
@@ -367,6 +368,14 @@
#define TLSEXT_CHANNEL_ID_SIZE 128
+/* SSL_CIPHER_ALGORITHM2_AEAD is a flag in SSL_CIPHER.algorithm2 which
+ * indicates that the cipher is implemented via an EVP_AEAD. */
+#define SSL_CIPHER_ALGORITHM2_AEAD (1<<23)
+
+/* SSL_CIPHER_AEAD_FIXED_NONCE_LEN returns the number of bytes of fixed nonce
+ * for an SSL_CIPHER* with the SSL_CIPHER_ALGORITHM2_AEAD flag. */
+#define SSL_CIPHER_AEAD_FIXED_NONCE_LEN(ssl_cipher) \
+ (((ssl_cipher->algorithm2 >> 24) & 0xf)*2)
/*
* Export and cipher strength information. For each cipher we have to decide
@@ -729,6 +738,17 @@
*/
#define SSL_ENC_FLAG_TLS1_2_CIPHERS 0x10
+/* ssl_aead_ctx_st contains information about an AEAD that is being used to
+ * encrypt an SSL connection. */
+struct ssl_aead_ctx_st
+ {
+ EVP_AEAD_CTX ctx;
+ /* fixed_nonce contains any bytes of the nonce that are fixed for all
+ * records. */
+ unsigned char fixed_nonce[8];
+ unsigned char fixed_nonce_len, variable_nonce_len, tag_len;
+ };
+
#ifndef OPENSSL_NO_COMP
/* Used for holding the relevant compression methods loaded into SSL_CTX */
typedef struct ssl3_comp_st
@@ -978,8 +998,11 @@
STACK_OF(SSL_CIPHER) **sorted,
const char *rule_str, CERT *c);
void ssl_update_cache(SSL *s, int mode);
+int ssl_cipher_get_comp(const SSL_SESSION *s, SSL_COMP **comp);
+int ssl_cipher_get_evp_aead(const SSL_SESSION *s, const EVP_AEAD **aead);
int ssl_cipher_get_evp(const SSL_SESSION *s,const EVP_CIPHER **enc,
- const EVP_MD **md,int *mac_pkey_type,int *mac_secret_size, SSL_COMP **comp);
+ const EVP_MD **md,int *mac_pkey_type,int *mac_secret_size);
+int ssl_get_handshake_digest(int i,long *mask,const EVP_MD **md);
int ssl_get_handshake_digest(int i,long *mask,const EVP_MD **md);
int ssl_cipher_get_cert_index(const SSL_CIPHER *c);
const SSL_CIPHER *ssl_get_cipher_by_char(SSL *ssl, const unsigned char *ptr);
diff --git a/ssl/ssl_txt.c b/ssl/ssl_txt.c
index da48076..6d3009a 100644
--- a/ssl/ssl_txt.c
+++ b/ssl/ssl_txt.c
@@ -133,7 +133,10 @@
if (x->cipher == NULL)
{
- if (((x->cipher_id) & 0xff000000) == 0x02000000)
+ SSL_COMP *comp = NULL;
+
+ ssl_cipher_get_comp(x, &comp);
+ if (comp == NULL)
{
if (BIO_printf(bp," Cipher : %06lX\n",x->cipher_id&0xffffff) <= 0)
goto err;
diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
index b351c51..58f8bf8 100644
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -311,6 +311,66 @@
return ret;
}
+/* tls1_aead_ctx_init allocates |*aead_ctx|, if needed and returns 1. It
+ * returns 0 on malloc error. */
+static int tls1_aead_ctx_init(SSL_AEAD_CTX **aead_ctx)
+ {
+ if (*aead_ctx != NULL)
+ EVP_AEAD_CTX_cleanup(&(*aead_ctx)->ctx);
+ else
+ {
+ *aead_ctx = (SSL_AEAD_CTX*) OPENSSL_malloc(sizeof(SSL_AEAD_CTX));
+ if (*aead_ctx == NULL)
+ {
+ OPENSSL_PUT_ERROR(SSL, tls1_aead_ctx_init, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ }
+
+ return 1;
+ }
+
+static int tls1_change_cipher_state_aead(SSL *s, char is_read,
+ const unsigned char *key, unsigned key_len,
+ const unsigned char *iv, unsigned iv_len)
+ {
+ const EVP_AEAD *aead = s->s3->tmp.new_aead;
+ SSL_AEAD_CTX *aead_ctx;
+
+ if (is_read)
+ {
+ if (!tls1_aead_ctx_init(&s->aead_read_ctx))
+ return 0;
+ aead_ctx = s->aead_read_ctx;
+ }
+ else
+ {
+ if (!tls1_aead_ctx_init(&s->aead_write_ctx))
+ return 0;
+ aead_ctx = s->aead_write_ctx;
+ }
+
+ if (!EVP_AEAD_CTX_init(&aead_ctx->ctx, aead, key, key_len,
+ EVP_AEAD_DEFAULT_TAG_LENGTH, NULL /* engine */))
+ return 0;
+ if (iv_len > sizeof(aead_ctx->fixed_nonce))
+ {
+ OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ memcpy(aead_ctx->fixed_nonce, iv, iv_len);
+ aead_ctx->fixed_nonce_len = iv_len;
+ aead_ctx->variable_nonce_len = 8; /* always the case, currently. */
+ if (aead_ctx->variable_nonce_len + aead_ctx->fixed_nonce_len != EVP_AEAD_nonce_length(aead))
+ {
+ OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ aead_ctx->tag_len = EVP_AEAD_max_overhead(aead);
+
+ return 1;
+ }
+
/* tls1_change_cipher_state_cipher performs the work needed to switch cipher
* states when using EVP_CIPHER. The argument |is_read| is true iff this
* function is being called due to reading, as opposed to writing, a
@@ -500,6 +560,7 @@
const unsigned char *client_write_key, *server_write_key, *key;
const unsigned char *client_write_iv, *server_write_iv, *iv;
const EVP_CIPHER *cipher = s->s3->tmp.new_sym_enc;
+ const EVP_AEAD *aead = s->s3->tmp.new_aead;
unsigned key_len, iv_len, mac_secret_len;
const unsigned char *key_data;
const char is_export = SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) != 0;
@@ -513,14 +574,22 @@
mac_secret_len = s->s3->tmp.new_mac_secret_size;
- key_len = EVP_CIPHER_key_length(cipher);
- if (is_export && key_len > SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher))
- key_len = SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher);
-
- if (EVP_CIPHER_mode(cipher) == EVP_CIPH_GCM_MODE)
- iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
+ if (aead != NULL)
+ {
+ key_len = EVP_AEAD_key_length(aead);
+ iv_len = SSL_CIPHER_AEAD_FIXED_NONCE_LEN(s->s3->tmp.new_cipher);
+ }
else
- iv_len = EVP_CIPHER_iv_length(cipher);
+ {
+ key_len = EVP_CIPHER_key_length(cipher);
+ if (is_export && key_len > SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher))
+ key_len = SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher);
+
+ if (EVP_CIPHER_mode(cipher) == EVP_CIPH_GCM_MODE)
+ iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
+ else
+ iv_len = EVP_CIPHER_iv_length(cipher);
+ }
key_data = s->s3->tmp.key_block;
client_write_mac_secret = key_data; key_data += mac_secret_len;
@@ -549,12 +618,20 @@
return 0;
}
- if (!tls1_change_cipher_state_cipher(s, is_read, use_client_keys,
- mac_secret, mac_secret_len,
- key, key_len,
- iv, iv_len)) {
- return 0;
- }
+ if (aead != NULL)
+ {
+ if (!tls1_change_cipher_state_aead(s, is_read,
+ key, key_len, iv, iv_len))
+ return 0;
+ }
+ else
+ {
+ if (!tls1_change_cipher_state_cipher(s, is_read, use_client_keys,
+ mac_secret, mac_secret_len,
+ key, key_len,
+ iv, iv_len))
+ return 0;
+ }
return 1;
}
@@ -562,13 +639,14 @@
int tls1_setup_key_block(SSL *s)
{
unsigned char *p1,*p2=NULL;
- const EVP_CIPHER *c;
- const EVP_MD *hash;
+ const EVP_CIPHER *c = NULL;
+ const EVP_MD *hash = NULL;
+ const EVP_AEAD *aead = NULL;
int num;
SSL_COMP *comp;
int mac_type= NID_undef,mac_secret_size=0;
int ret=0;
- int iv_len;
+ unsigned key_len, iv_len;
#ifdef KSSL_DEBUG
printf ("tls1_setup_key_block()\n");
@@ -577,22 +655,36 @@
if (s->s3->tmp.key_block_length != 0)
return(1);
- if (!ssl_cipher_get_evp(s->session,&c,&hash,&mac_type,&mac_secret_size,&comp))
+ if (!ssl_cipher_get_comp(s->session, &comp))
+ goto cipher_unavailable_err;
+
+ if (s->session->cipher &&
+ (s->session->cipher->algorithm2 & SSL_CIPHER_ALGORITHM2_AEAD))
{
- OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
- return(0);
+ if (!ssl_cipher_get_evp_aead(s->session, &aead))
+ goto cipher_unavailable_err;
+ key_len = EVP_AEAD_key_length(aead);
+ iv_len = SSL_CIPHER_AEAD_FIXED_NONCE_LEN(s->session->cipher);
+ }
+ else
+ {
+ if (!ssl_cipher_get_evp(s->session,&c,&hash,&mac_type,&mac_secret_size))
+ goto cipher_unavailable_err;
+ key_len = EVP_CIPHER_key_length(c);
+
+ if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
+ iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
+ else
+ iv_len = EVP_CIPHER_iv_length(c);
}
- if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
- iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
- else
- iv_len = EVP_CIPHER_iv_length(c);
-
+ s->s3->tmp.new_aead=aead;
s->s3->tmp.new_sym_enc=c;
s->s3->tmp.new_hash=hash;
s->s3->tmp.new_mac_pkey_type = mac_type;
s->s3->tmp.new_mac_secret_size = mac_secret_size;
- num=EVP_CIPHER_key_length(c)+mac_secret_size+iv_len;
+
+ num=key_len+mac_secret_size+iv_len;
num*=2;
ssl3_cleanup_key_block(s);
@@ -655,6 +747,10 @@
OPENSSL_free(p2);
}
return(ret);
+
+cipher_unavailable_err:
+ OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
+ return 0;
}
/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
@@ -673,6 +769,132 @@
unsigned long l;
int bs,i,j,k,pad=0,ret,mac_size=0;
const EVP_CIPHER *enc;
+ const SSL_AEAD_CTX *aead;
+
+ if (send)
+ rec = &s->s3->wrec;
+ else
+ rec = &s->s3->rrec;
+
+ if (send)
+ aead = s->aead_write_ctx;
+ else
+ aead = s->aead_read_ctx;
+
+ if (aead)
+ {
+ unsigned char ad[13], *seq, *in, *out, nonce[16];
+ unsigned nonce_used;
+ size_t n;
+
+ seq = send ? s->s3->write_sequence : s->s3->read_sequence;
+
+ if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
+ {
+ unsigned char dtlsseq[9], *p = dtlsseq;
+
+ s2n(send ? s->d1->w_epoch : s->d1->r_epoch, p);
+ memcpy(p, &seq[2], 6);
+ memcpy(ad, dtlsseq, 8);
+ }
+ else
+ {
+ memcpy(ad, seq, 8);
+ for (i=7; i>=0; i--) /* increment */
+ {
+ ++seq[i];
+ if (seq[i] != 0)
+ break;
+ }
+ }
+
+ ad[8] = rec->type;
+ ad[9] = (unsigned char)(s->version>>8);
+ ad[10] = (unsigned char)(s->version);
+
+ if (aead->fixed_nonce_len + aead->variable_nonce_len > sizeof(nonce) ||
+ aead->variable_nonce_len > 8)
+ return -1; /* internal error - should never happen. */
+
+ memcpy(nonce, aead->fixed_nonce, aead->fixed_nonce_len);
+ nonce_used = aead->fixed_nonce_len;
+
+ if (send)
+ {
+ size_t len = rec->length;
+ in = rec->input;
+ out = rec->data;
+
+ /* When sending we use the sequence number as the
+ * variable part of the nonce. */
+ if (aead->variable_nonce_len > 8)
+ return -1;
+ memcpy(nonce + nonce_used, ad, aead->variable_nonce_len);
+ nonce_used += aead->variable_nonce_len;
+
+ /* in do_ssl3_write, rec->input is moved forward by
+ * variable_nonce_len in order to leave space for the
+ * variable nonce. Thus we can copy the sequence number
+ * bytes into place without overwriting any of the
+ * plaintext. */
+ memcpy(out, ad, aead->variable_nonce_len);
+ len -= aead->variable_nonce_len;
+
+ ad[11] = len >> 8;
+ ad[12] = len & 0xff;
+
+ if (!EVP_AEAD_CTX_seal(
+ &aead->ctx,
+ out + aead->variable_nonce_len, &n, len + aead->tag_len,
+ nonce, nonce_used,
+ in + aead->variable_nonce_len, len,
+ ad, sizeof(ad)))
+ {
+ return -1;
+ }
+ n += aead->variable_nonce_len;
+ }
+ else
+ {
+ /* receive */
+ size_t len = rec->length;
+
+ if (rec->data != rec->input)
+ return -1; /* internal error - should never happen. */
+ out = in = rec->input;
+
+ if (len < aead->variable_nonce_len)
+ return 0;
+ memcpy(nonce + nonce_used, in, aead->variable_nonce_len);
+ nonce_used += aead->variable_nonce_len;
+
+ in += aead->variable_nonce_len;
+ len -= aead->variable_nonce_len;
+ out += aead->variable_nonce_len;
+
+ if (len < aead->tag_len)
+ return 0;
+ len -= aead->tag_len;
+
+ ad[11] = len >> 8;
+ ad[12] = len & 0xff;
+
+ if (!EVP_AEAD_CTX_open(
+ &aead->ctx,
+ out, &n, len,
+ nonce, nonce_used,
+ in, len + aead->tag_len,
+ ad, sizeof(ad)))
+ {
+ return -1;
+ }
+
+ rec->data = rec->input = out;
+ }
+
+ rec->length = n;
+ return 1;
+ }
if (send)
{
