We currently have a number of calls that fetch the cipher_kt from a
cipher_ctx to then do a query on the cipher_kt. Directly fetching the
desired property from the context is cleaner and helps for using the
proper APIs with OpenSSL 3.0 and mbed TLS 3.0
Signed-off-by: Arne Schwabe <a...@rfc2549.org>
---
src/openvpn/crypto.c | 36 ++++++++---------------
src/openvpn/crypto_backend.h | 29 ++++++++++++++----
src/openvpn/crypto_mbedtls.c | 21 +++++++++++--
src/openvpn/crypto_openssl.c | 57 ++++++++++++++++++++++++++++++++++--
src/openvpn/openssl_compat.h | 1 +
src/openvpn/ssl.c | 8 ++---
src/openvpn/ssl_ncp.c | 18 +++++-------
7 files changed, 119 insertions(+), 51 deletions(-)
diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index 270d83c56..27ed1402c 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -68,12 +68,10 @@ openvpn_encrypt_aead(struct buffer *buf, struct buffer work,
int outlen = 0;
const struct key_ctx *ctx = &opt->key_ctx_bi.encrypt;
uint8_t *mac_out = NULL;
- const cipher_kt_t *cipher_kt = cipher_ctx_get_cipher_kt(ctx->cipher);
const int mac_len = OPENVPN_AEAD_TAG_LENGTH;
/* IV, packet-ID and implicit IV required for this mode. */
ASSERT(ctx->cipher);
- ASSERT(cipher_kt_mode_aead(cipher_kt));
ASSERT(packet_id_initialized(&opt->packet_id));
gc_init(&gc);
@@ -171,7 +169,6 @@ openvpn_encrypt_v1(struct buffer *buf, struct buffer work,
{
uint8_t iv_buf[OPENVPN_MAX_IV_LENGTH] = {0};
const int iv_size = cipher_ctx_iv_length(ctx->cipher);
- const cipher_kt_t *cipher_kt =
cipher_ctx_get_cipher_kt(ctx->cipher);
int outlen;
/* Reserve space for HMAC */
@@ -182,7 +179,7 @@ openvpn_encrypt_v1(struct buffer *buf, struct buffer work,
hmac_start = BEND(&work);
}
- if (cipher_kt_mode_cbc(cipher_kt))
+ if (cipher_ctx_mode_cbc(ctx->cipher))
{
/* generate pseudo-random IV */
prng_bytes(iv_buf, iv_size);
@@ -197,7 +194,7 @@ openvpn_encrypt_v1(struct buffer *buf, struct buffer work,
goto err;
}
}
- else if (cipher_kt_mode_ofb_cfb(cipher_kt))
+ else if (cipher_ctx_mode_ofb_cfb(ctx->cipher))
{
struct buffer b;
@@ -245,7 +242,7 @@ openvpn_encrypt_v1(struct buffer *buf, struct buffer work,
ASSERT(buf_inc_len(&work, outlen));
/* For all CBC mode ciphers, check the last block is complete */
- ASSERT(cipher_kt_mode(cipher_kt) != OPENVPN_MODE_CBC
+ ASSERT(cipher_ctx_mode(ctx->cipher) != OPENVPN_MODE_CBC
|| outlen == iv_size);
}
else /* No Encryption */
@@ -301,10 +298,7 @@ openvpn_encrypt(struct buffer *buf, struct buffer work,
{
if (buf->len > 0 && opt)
{
- const cipher_kt_t *cipher_kt =
- cipher_ctx_get_cipher_kt(opt->key_ctx_bi.encrypt.cipher);
-
- if (cipher_kt_mode_aead(cipher_kt))
+ if (cipher_ctx_mode_aead(opt->key_ctx_bi.encrypt.cipher))
{
openvpn_encrypt_aead(buf, work, opt);
}
@@ -360,7 +354,6 @@ openvpn_decrypt_aead(struct buffer *buf, struct buffer work,
static const char error_prefix[] = "AEAD Decrypt error";
struct packet_id_net pin = { 0 };
const struct key_ctx *ctx = &opt->key_ctx_bi.decrypt;
- const cipher_kt_t *cipher_kt = cipher_ctx_get_cipher_kt(ctx->cipher);
uint8_t *tag_ptr = NULL;
int outlen;
struct gc_arena gc;
@@ -371,7 +364,6 @@ openvpn_decrypt_aead(struct buffer *buf, struct buffer work,
ASSERT(frame);
ASSERT(buf->len > 0);
ASSERT(ctx->cipher);
- ASSERT(cipher_kt_mode_aead(cipher_kt));
dmsg(D_PACKET_CONTENT, "DECRYPT FROM: %s",
format_hex(BPTR(buf), BLEN(buf), 80, &gc));
@@ -537,7 +529,6 @@ openvpn_decrypt_v1(struct buffer *buf, struct buffer work,
if (ctx->cipher)
{
const int iv_size = cipher_ctx_iv_length(ctx->cipher);
- const cipher_kt_t *cipher_kt =
cipher_ctx_get_cipher_kt(ctx->cipher);
uint8_t iv_buf[OPENVPN_MAX_IV_LENGTH] = { 0 };
int outlen;
@@ -589,7 +580,7 @@ openvpn_decrypt_v1(struct buffer *buf, struct buffer work,
/* Get packet ID from plaintext buffer or IV, depending on cipher
mode */
{
- if (cipher_kt_mode_cbc(cipher_kt))
+ if (cipher_ctx_mode_cbc(ctx->cipher))
{
if (packet_id_initialized(&opt->packet_id))
{
@@ -600,7 +591,7 @@ openvpn_decrypt_v1(struct buffer *buf, struct buffer work,
have_pin = true;
}
}
- else if (cipher_kt_mode_ofb_cfb(cipher_kt))
+ else if (cipher_ctx_mode_ofb_cfb(ctx->cipher))
{
struct buffer b;
@@ -660,8 +651,7 @@ openvpn_decrypt(struct buffer *buf, struct buffer work,
if (buf->len > 0 && opt)
{
- const struct key_ctx *ctx = &opt->key_ctx_bi.decrypt;
- if (cipher_kt_mode_aead(cipher_ctx_get_cipher_kt(ctx->cipher)))
+ if (cipher_ctx_mode_aead(opt->key_ctx_bi.decrypt.cipher))
{
ret = openvpn_decrypt_aead(buf, work, opt, frame, ad_start);
}
@@ -1036,14 +1026,12 @@ test_crypto(struct crypto_options *co, struct frame
*frame)
/* init implicit IV */
{
- const cipher_kt_t *cipher =
- cipher_ctx_get_cipher_kt(co->key_ctx_bi.encrypt.cipher);
-
- if (cipher_kt_mode_aead(cipher))
+ cipher_ctx_t *cipher = co->key_ctx_bi.encrypt.cipher;
+ if (cipher_ctx_mode_aead(cipher))
{
- size_t impl_iv_len = cipher_kt_iv_size(cipher) -
sizeof(packet_id_type);
- ASSERT(cipher_kt_iv_size(cipher) <= OPENVPN_MAX_IV_LENGTH);
- ASSERT(cipher_kt_iv_size(cipher) >= OPENVPN_AEAD_MIN_IV_LEN);
+ size_t impl_iv_len = cipher_ctx_iv_length(cipher) -
sizeof(packet_id_type);
+ ASSERT(cipher_ctx_iv_length(cipher) <= OPENVPN_MAX_IV_LENGTH);
+ ASSERT(cipher_ctx_iv_length(cipher) >= OPENVPN_AEAD_MIN_IV_LEN);
/* Generate dummy implicit IV */
ASSERT(rand_bytes(co->key_ctx_bi.encrypt.implicit_iv,
diff --git a/src/openvpn/crypto_backend.h b/src/openvpn/crypto_backend.h
index 7c1f123e4..925d1db37 100644
--- a/src/openvpn/crypto_backend.h
+++ b/src/openvpn/crypto_backend.h
@@ -338,7 +338,7 @@ void cipher_ctx_init(cipher_ctx_t *ctx, const uint8_t *key,
int key_len,
* @param ctx The cipher's context
*
* @return Size of the IV, in bytes, or \c 0 if the cipher does
not
- * use an IV or ctx was NULL.
+ * use an IV.
*/
int cipher_ctx_iv_length(const cipher_ctx_t *ctx);
@@ -371,14 +371,31 @@ int cipher_ctx_block_size(const cipher_ctx_t *ctx);
int cipher_ctx_mode(const cipher_ctx_t *ctx);
/**
- * Returns the static cipher parameters for this context.
+ * Check if the supplied cipher is a supported CBC mode cipher.
+ *
+ * @param ctx Cipher's context. May not be NULL.
+ *
+ * @return true iff the cipher is a CBC mode cipher.
+ */
+bool cipher_ctx_mode_cbc(const cipher_ctx_t *ctx);
+
+/**
+ * Check if the supplied cipher is a supported OFB or CFB mode cipher.
+ *
+ * @param ctx Cipher's context. May not be NULL.
+ *
+ * @return true iff the cipher is a OFB or CFB mode cipher.
+ */
+bool cipher_ctx_mode_ofb_cfb(const cipher_ctx_t *ctx);
+
+/**
+ * Check if the supplied cipher is a supported AEAD mode cipher.
*
- * @param ctx Cipher's context.
+ * @param ctx Cipher's context. May not be NULL.
*
- * @return Static cipher parameters for the supplied context, or
- * NULL if unable to determine cipher parameters.
+ * @return true iff the cipher is a AEAD mode cipher.
*/
-const cipher_kt_t *cipher_ctx_get_cipher_kt(const cipher_ctx_t *ctx);
+bool cipher_ctx_mode_aead(const cipher_ctx_t *ctx);
/**
* Resets the given cipher context, setting the IV to the specified value.
diff --git a/src/openvpn/crypto_mbedtls.c b/src/openvpn/crypto_mbedtls.c
index 893a4ab02..566baadde 100644
--- a/src/openvpn/crypto_mbedtls.c
+++ b/src/openvpn/crypto_mbedtls.c
@@ -591,10 +591,25 @@ cipher_ctx_mode(const mbedtls_cipher_context_t *ctx)
return cipher_kt_mode(ctx->cipher_info);
}
-const cipher_kt_t *
-cipher_ctx_get_cipher_kt(const cipher_ctx_t *ctx)
+bool cipher_ctx_mode_cbc(const cipher_ctx_t *ctx)
{
- return ctx ? ctx->cipher_info : NULL;
+ return ctx && cipher_ctx_mode(ctx) == OPENVPN_MODE_CBC;
+}
+
+
+bool cipher_ctx_mode_ofb_cfb(const cipher_ctx_t *ctx)
+{
+ return ctx && (cipher_ctx_mode(ctx) == OPENVPN_MODE_OFB
+ || cipher_ctx_mode(ctx) == OPENVPN_MODE_CFB);
+}
+
+bool cipher_ctx_mode_aead(const cipher_ctx_t *ctx)
+{
+ return ctx && (cipher_ctx_mode(ctx) == OPENVPN_MODE_GCM
+#ifdef MBEDTLS_CHACHAPOLY_C
+ || cipher_ctx_mode(ctx) == MBEDTLS_MODE_CHACHAPOLY
+#endif
+ );
}
int
diff --git a/src/openvpn/crypto_openssl.c b/src/openvpn/crypto_openssl.c
index 3044ea944..9d6c7c807 100644
--- a/src/openvpn/crypto_openssl.c
+++ b/src/openvpn/crypto_openssl.c
@@ -797,10 +797,61 @@ cipher_ctx_mode(const EVP_CIPHER_CTX *ctx)
return EVP_CIPHER_CTX_mode(ctx);
}
-const cipher_kt_t *
-cipher_ctx_get_cipher_kt(const cipher_ctx_t *ctx)
+
+bool
+cipher_ctx_mode_cbc(const cipher_ctx_t *ctx)
+{
+ if (!ctx)
+ {
+ return false;
+ }
+
+ int flags = EVP_CIPHER_CTX_flags(ctx);
+ int mode = EVP_CIPHER_CTX_mode(ctx);
+
+ return mode == EVP_CIPH_CBC_MODE
+ /* Exclude AEAD cipher modes, they require a different API */
+#ifdef EVP_CIPH_FLAG_CTS
+ && !(flags & EVP_CIPH_FLAG_CTS)
+#endif
+ && !(flags & EVP_CIPH_FLAG_AEAD_CIPHER);
+}
+
+bool
+cipher_ctx_mode_ofb_cfb(const cipher_ctx_t *ctx)
+{
+ if (!ctx)
+ {
+ return false;
+ }
+
+ int mode = EVP_CIPHER_CTX_get_mode(ctx);
+
+ return (mode == EVP_CIPH_OFB_MODE || mode == EVP_CIPH_CFB_MODE)
+ /* Exclude AEAD cipher modes, they require a different API */
+ && !(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_FLAG_AEAD_CIPHER);
+}
+
+bool
+cipher_ctx_mode_aead(const cipher_ctx_t *ctx)
{
- return ctx ? EVP_CIPHER_CTX_cipher(ctx) : NULL;
+ if (ctx)
+ {
+ int flags = EVP_CIPHER_CTX_flags(ctx);
+ if (flags & EVP_CIPH_FLAG_AEAD_CIPHER)
+ {
+ return true;
+ }
+
+#if defined(NID_chacha20_poly1305) && OPENSSL_VERSION_NUMBER < 0x30000000L
+ if (EVP_CIPHER_CTX_nid(ctx) == NID_chacha20_poly1305)
+ {
+ return true;
+ }
+#endif
+ }
+
+ return false;
}
diff --git a/src/openvpn/openssl_compat.h b/src/openvpn/openssl_compat.h
index cbd7fd1d2..54fd5d60f 100644
--- a/src/openvpn/openssl_compat.h
+++ b/src/openvpn/openssl_compat.h
@@ -757,6 +757,7 @@ int EVP_PKEY_get_group_name(EVP_PKEY *pkey, char *gname,
size_t gname_sz,
#if OPENSSL_VERSION_NUMBER < 0x30000000L
#define EVP_MD_get0_name EVP_MD_name
+#define EVP_CIPHER_CTX_get_mode EVP_CIPHER_CTX_mode
/* Mimics the functions but only when the default context without
* options is chosen */
diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
index ad3e08274..3de229e39 100644
--- a/src/openvpn/ssl.c
+++ b/src/openvpn/ssl.c
@@ -1803,14 +1803,12 @@ exit:
static void
key_ctx_update_implicit_iv(struct key_ctx *ctx, uint8_t *key, size_t key_len)
{
- const cipher_kt_t *cipher_kt = cipher_ctx_get_cipher_kt(ctx->cipher);
-
/* Only use implicit IV in AEAD cipher mode, where HMAC key is not used */
- if (cipher_kt_mode_aead(cipher_kt))
+ if (cipher_ctx_mode_aead(ctx->cipher))
{
size_t impl_iv_len = 0;
- ASSERT(cipher_kt_iv_size(cipher_kt) >= OPENVPN_AEAD_MIN_IV_LEN);
- impl_iv_len = cipher_kt_iv_size(cipher_kt) - sizeof(packet_id_type);
+ ASSERT(cipher_ctx_iv_length(ctx->cipher) >= OPENVPN_AEAD_MIN_IV_LEN);
+ impl_iv_len = cipher_ctx_iv_length(ctx->cipher) -
sizeof(packet_id_type);
ASSERT(impl_iv_len <= OPENVPN_MAX_IV_LENGTH);
ASSERT(impl_iv_len <= key_len);
memcpy(ctx->implicit_iv, key, impl_iv_len);
diff --git a/src/openvpn/ssl_ncp.c b/src/openvpn/ssl_ncp.c
index b0b248aae..e5cfbd180 100644
--- a/src/openvpn/ssl_ncp.c
+++ b/src/openvpn/ssl_ncp.c
@@ -466,19 +466,17 @@ p2p_mode_ncp(struct tls_multi *multi, struct tls_session
*session)
if (!common_cipher)
{
struct buffer out = alloc_buf_gc(128, &gc);
- struct key_state *ks = get_key_scan(multi, KS_PRIMARY);
+ const cipher_kt_t *cipher = session->opt->key_type.cipher;
- const cipher_ctx_t *ctx = ks->crypto_options.key_ctx_bi.encrypt.cipher;
- const cipher_kt_t *cipher = cipher_ctx_get_cipher_kt(ctx);
- const char *fallback_name = cipher_kt_name(cipher);
+ /* at this point we do not really know if our fallback is
+ * not enabled or if we use 'none' cipher as fallback, so
+ * keep this ambiguity here and print fallback-cipher: none
+ */
- if (!cipher)
+ const char *fallback_name = "none";
+ if (cipher)
{
- /* at this point we do not really know if our fallback is
- * not enabled or if we use 'none' cipher as fallback, so
- * keep this ambiguity here and print fallback-cipher: none
- */
- fallback_name = "none";
+ fallback_name = cipher_kt_name(cipher);
}
buf_printf(&out, "(not negotiated, fallback-cipher: %s)",
fallback_name);
--
2.33.0
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