From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Tue, 16 May 2023 16:11:01 +0000 (+0200)
Subject: MINOR: quic: remove return val of quic_aead_iv_build()
X-Git-Tag: v2.8-dev13~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5eadc27623fb68c14a4217c4567bcc78cc5deddd;p=thirdparty%2Fhaproxy.git

MINOR: quic: remove return val of quic_aead_iv_build()

quic_aead_iv_build() should never fail unless we call it with buffers of
different size. This never happens in the code as every input buffers
are of size QUIC_TLS_IV_LEN.

Remove the return value and add a BUG_ON() to prevent future misusage.
This is especially useful to remove one error handling on the sending
patch via quic_packet_encrypt().

This should be backported up to 2.7.
---

diff --git a/include/haproxy/quic_tls.h b/include/haproxy/quic_tls.h
index a2eb2230a1..7b5e043a1b 100644
--- a/include/haproxy/quic_tls.h
+++ b/include/haproxy/quic_tls.h
@@ -96,8 +96,8 @@ int quic_tls_sec_update(const EVP_MD *md, const struct quic_version *qv,
                         unsigned char *new_sec, size_t new_seclen,
                         const unsigned char *sec, size_t seclen);
 
-int quic_aead_iv_build(unsigned char *iv, size_t ivlen,
-                       unsigned char *aead_iv, size_t aead_ivlen, uint64_t pn);
+void quic_aead_iv_build(unsigned char *iv, size_t ivlen,
+                        unsigned char *aead_iv, size_t aead_ivlen, uint64_t pn);
 
 /* HP protection (AES) */
 int quic_tls_dec_aes_ctx_init(EVP_CIPHER_CTX **aes_ctx,
diff --git a/src/quic_conn.c b/src/quic_conn.c
index b60736210e..2d58bc1779 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -1542,10 +1542,7 @@ static int quic_packet_encrypt(unsigned char *payload, size_t payload_len,
 
 	TRACE_ENTER(QUIC_EV_CONN_ENCPKT, qc);
 
-	if (!quic_aead_iv_build(iv, sizeof iv, tx_iv, tx_iv_sz, pn)) {
-		TRACE_ERROR("AEAD IV building for encryption failed", QUIC_EV_CONN_ENCPKT, qc);
-		goto err;
-	}
+	quic_aead_iv_build(iv, sizeof iv, tx_iv, tx_iv_sz, pn);
 
 	if (!quic_tls_encrypt(payload, payload_len, aad, aad_len,
 	                      tls_ctx->tx.ctx, tls_ctx->tx.aead, tls_ctx->tx.key, iv)) {
@@ -1626,10 +1623,7 @@ static int qc_pkt_decrypt(struct quic_conn *qc, struct quic_enc_level *qel,
 		}
 	}
 
-	if (!quic_aead_iv_build(iv, sizeof iv, rx_iv, rx_iv_sz, pkt->pn)) {
-		TRACE_ERROR("quic_aead_iv_build() failed", QUIC_EV_CONN_RXPKT, qc);
-		goto leave;
-	}
+	quic_aead_iv_build(iv, sizeof iv, rx_iv, rx_iv_sz, pkt->pn);
 
 	ret = quic_tls_decrypt(pkt->data + pkt->aad_len, pkt->len - pkt->aad_len,
 	                       pkt->data, pkt->aad_len,
diff --git a/src/quic_tls.c b/src/quic_tls.c
index edd45e76a5..0513ec07ff 100644
--- a/src/quic_tls.c
+++ b/src/quic_tls.c
@@ -326,17 +326,16 @@ int quic_tls_sec_update(const EVP_MD *md, const struct quic_version *qv,
  * <aead_ivlen> as size depending on <pn> packet number.
  * This is the function which must be called to build an AEAD IV for the AEAD cryptographic algorithm
  * used to encrypt/decrypt the QUIC packet payloads depending on the packet number <pn>.
- * This function fails and return 0 only if the two buffer lengths are different, 1 if not.
  */
-int quic_aead_iv_build(unsigned char *iv, size_t ivlen,
-                       unsigned char *aead_iv, size_t aead_ivlen, uint64_t pn)
+void quic_aead_iv_build(unsigned char *iv, size_t ivlen,
+                        unsigned char *aead_iv, size_t aead_ivlen, uint64_t pn)
 {
 	int i;
 	unsigned int shift;
 	unsigned char *pos = iv;
 
-	if (ivlen != aead_ivlen)
-		return 0;
+	/* Input buffers must have the same size. */
+	BUG_ON(ivlen != aead_ivlen);
 
 	for (i = 0; i < ivlen - sizeof pn; i++)
 		*pos++ = *aead_iv++;
@@ -345,8 +344,6 @@ int quic_aead_iv_build(unsigned char *iv, size_t ivlen,
 	shift = 56;
 	for (i = aead_ivlen - sizeof pn; i < aead_ivlen ; i++, shift -= 8)
 		*pos++ = *aead_iv++ ^ (pn >> shift);
-
-	return 1;
 }
 
 /* Initialize the cipher context for RX part of <tls_ctx> QUIC TLS context.