diff --git a/draft-ietf-httpbis-encryption-encoding.md b/draft-ietf-httpbis-encryption-encoding.md index d0592f7a7..7d4620f89 100644 --- a/draft-ietf-httpbis-encryption-encoding.md +++ b/draft-ietf-httpbis-encryption-encoding.md @@ -128,13 +128,11 @@ necessary to negotiate the use of encryption. The "aes128gcm" content coding uses a fixed record size. The final encoding consists of a header (see {{header}}), zero or more fixed size encrypted -records, and a partial record. The partial record MUST be shorter than the -fixed record size. +records. The final record can be smaller than the record size. The record size determines the length of each portion of plaintext that is -enciphered, with the exception of the final record, which is necessarily -smaller. The record size ("rs") is included in the content coding header (see -{{header}}). +enciphered. The record size ("rs") is included in the content coding header +(see {{header}}). ~~~ drawing +-----------+ content of rs octets @@ -149,7 +147,7 @@ smaller. The record size ("rs") is included in the content coding header (see v +--------------------+ encrypt with AEAD_AES_128_GCM; | ciphertext | final size is rs; -+--------------------+ the last record is smaller ++--------------------+ the last record can be smaller ~~~ AEAD_AES_128_GCM produces ciphertext 16 octets longer than its input plaintext. @@ -186,7 +184,7 @@ random access into the ciphertext is needed. Applications that don't depending on streaming, random access, or arbitrary padding can use larger records, or even a single record. A larger record size -reduces the processing and data overheads. +reduces processing and data overheads. ## Encryption Content Coding Header {#header}