Add an SSL_CIPHER_ALGORITHM2_AEAD flag that is used to mark a cipher as

using EVP_AEAD. Also provide an EVP_AEAD-only equivalent of
ssl_cipher_get_evp().

2 files changed, 57 insertions, 0 deletions

diff --git a/lib/libssl/src/ssl/ssl_ciph.c b/lib/libssl/src/ssl/ssl_ciph.c
index b3bcc66f668..41004ce50ae 100644
--- a/lib/libssl/src/ssl/ssl_ciph.c
+++ b/lib/libssl/src/ssl/ssl_ciph.c
@@ -758,6 +758,13 @@ ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
 	if (c == NULL)
 		return (0);
 
+	/*
+	 * This function does not handle EVP_AEAD.
+	 * See ssl_cipher_get_aead_evp instead.
+	 */
+	if (c->algorithm2 & SSL_CIPHER_ALGORITHM2_AEAD)
+		return(0);
+
 	if ((enc == NULL) || (md == NULL))
 		return (0);
 
@@ -884,6 +891,37 @@ ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
 		return (0);
 }
 
+/*
+ * 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;
+
+	switch (c->algorithm_enc) {
+#ifndef OPENSSL_NO_AES
+	case SSL_AES128GCM:
+		*aead = EVP_aead_aes_128_gcm();
+		return 1;
+	case SSL_AES256GCM:
+		*aead = EVP_aead_aes_256_gcm();
+		return 1;
+#endif
+	default:
+		break;
+	}
+	return 0;
+}
+
 int
 ssl_get_handshake_digest(int idx, long *mask, const EVP_MD **md)
 {
diff --git a/lib/libssl/src/ssl/ssl_locl.h b/lib/libssl/src/ssl/ssl_locl.h
index a96402ec5cd..6374522f5fc 100644
--- a/lib/libssl/src/ssl/ssl_locl.h
+++ b/lib/libssl/src/ssl/ssl_locl.h
@@ -346,7 +346,25 @@
  * (currently this also goes into algorithm2) */
 #define TLS1_STREAM_MAC 0x04
 
+/*
+ * SSL_CIPHER_ALGORITHM2_VARIABLE_NONCE_IN_RECORD is an algorithm2 flag that
+ * indicates that the variable part of the nonce is included as a prefix of
+ * the record (AES-GCM, for example, does this with an 8-byte variable nonce.)
+ */
+#define SSL_CIPHER_ALGORITHM2_VARIABLE_NONCE_IN_RECORD (1 << 22)
+ 
+/*
+ * SSL_CIPHER_ALGORITHM2_AEAD is an algorithm2 flag that indicates 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
@@ -607,6 +625,7 @@ 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(const SSL_SESSION *s, const EVP_CIPHER **enc,
     const EVP_MD **md, int *mac_pkey_type, int *mac_secret_size);
+int ssl_cipher_get_evp_aead(const SSL_SESSION *s, const EVP_AEAD **aead);
 int ssl_get_handshake_digest(int i, long *mask, const EVP_MD **md);
 
 int ssl_verify_cert_chain(SSL *s, STACK_OF(X509) *sk);