diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c index b6825d20c2dc0bba5c199fef9c76dbbab8d88d35..f7ab0fa4704003dbf111e41667b6695875b9405d 100644 --- a/ssl/tls13_enc.c +++ b/ssl/tls13_enc.c @@ -13,14 +13,7 @@ #include #include -/* - * RFC 8446, 7.1 Key Schedule, says: - * Note: With common hash functions, any label longer than 12 characters - * requires an additional iteration of the hash function to compute. - * The labels in this specification have all been chosen to fit within - * this limit. - */ -#define TLS13_MAX_LABEL_LEN 12 +#define TLS13_MAX_LABEL_LEN 246 /* Always filled with zeros */ static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; @@ -36,15 +29,14 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, const unsigned char *data, size_t datalen, unsigned char *out, size_t outlen) { - static const unsigned char label_prefix[] = "tls13 "; + const unsigned char label_prefix[] = "tls13 "; EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); int ret; size_t hkdflabellen; size_t hashlen; /* - * 2 bytes for length of derived secret + 1 byte for length of combined - * prefix and label + bytes for the label itself + 1 byte length of hash - * + bytes for the hash itself + * 2 bytes for length of whole HkdfLabel + 1 byte for length of combined + * prefix and label + bytes for the label itself + bytes for the hash */ unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) + + sizeof(label_prefix) + TLS13_MAX_LABEL_LEN