Minor fixes and improvements in TLS 1.3 key schedule documentation

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 188b947..7b78c73 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -379,7 +379,7 @@
                                      const unsigned char *random, size_t rlen,
                                      unsigned char *dstbuf, size_t dlen );
 
-/* cipher.h exports the maximum IV, key and block length from all
+/* cipher.h exports the maximum IV, key and block length from
  * all ciphers enabled in the config, regardless of whether those
  * ciphers are actually usable in SSL/TLS. Notably, XTS is enabled
  * in the default configuration and uses 64 Byte keys, but it is
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 5a6204e..d641b16 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -59,15 +59,15 @@
  *                   255. This allows us to save a few Bytes of code by
  *                   hardcoding the writing of the high bytes.
  * - (label, llen): label + label length, without "tls13 " prefix
- *                  The label length MUST be
- *                  <= MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_LABEL_LEN
- *                  It is the caller's responsiblity to ensure this.
+ *                  The label length MUST be less than or equal to
+ *                  MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_LABEL_LEN
+ *                  It is the caller's responsibility to ensure this.
  *                  All (label, label length) pairs used in TLS 1.3
  *                  can be obtained via MBEDTLS_SSL_TLS1_3_LBL_WITH_LEN().
  * - (ctx, clen): context + context length
- *                The context length MUST be
- *                <= MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_CONTEXT_LEN
- *                It is the caller's responsiblity to ensure this.
+ *                The context length MUST be less than or equal to
+ *                MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_CONTEXT_LEN
+ *                It is the caller's responsibility to ensure this.
  * - dst: Target buffer for HkdfLabel structure,
  *        This MUST be a writable buffer of size
  *        at least SSL_TLS1_3_KEY_SCHEDULE_MAX_HKDF_LABEL_LEN Bytes.
@@ -296,7 +296,7 @@
     hlen = mbedtls_md_get_size( md );
 
     /* For non-initial runs, call Derive-Secret( ., "derived", "")
-     * on the old secreet. */
+     * on the old secret. */
     if( secret_old != NULL )
     {
         ret = mbedtls_ssl_tls1_3_derive_secret(
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index 7a9e5c9..73b8aaf 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -64,7 +64,7 @@
 #define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_LABEL_LEN  \
     sizeof( union mbedtls_ssl_tls1_3_labels_union )
 
-/* The maximum length of HKDF contexts used in the TLS 1.3 standad.
+/* The maximum length of HKDF contexts used in the TLS 1.3 standard.
  * Since contexts are always hashes of message transcripts, this can
  * be approximated from above by the maximum hash size. */
 #define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_CONTEXT_LEN  \
@@ -94,7 +94,7 @@
  *                  This must be a readable buffer of length \p clen Bytes.
  * \param clen      The length of \p context in Bytes.
  * \param buf       The destination buffer to hold the expanded secret.
- *                  This must be a writable buffe of length \p blen Bytes.
+ *                  This must be a writable buffer of length \p blen Bytes.
  * \param blen      The desired size of the expanded secret in Bytes.
  *
  * \returns         \c 0 on success.