From 6096a289848a9558b9852d740c3bde4cf1a7bd7e Mon Sep 17 00:00:00 2001 From: Sumner Evans Date: Mon, 26 Feb 2024 09:24:52 -0700 Subject: [PATCH] sas: clarify HKDF calculation uses base64-encoded keys (#1719) --- changelogs/client_server/newsfragments/1719.clarification | 1 + .../client-server-api/modules/end_to_end_encryption.md | 8 ++++---- 2 files changed, 5 insertions(+), 4 deletions(-) create mode 100644 changelogs/client_server/newsfragments/1719.clarification diff --git a/changelogs/client_server/newsfragments/1719.clarification b/changelogs/client_server/newsfragments/1719.clarification new file mode 100644 index 00000000..031e1e41 --- /dev/null +++ b/changelogs/client_server/newsfragments/1719.clarification @@ -0,0 +1 @@ +Clarify that the HKDF calculation for SAS uses base64-encoded keys rather than the raw key bytes. diff --git a/content/client-server-api/modules/end_to_end_encryption.md b/content/client-server-api/modules/end_to_end_encryption.md index 880082bb..1126c648 100644 --- a/content/client-server-api/modules/end_to_end_encryption.md +++ b/content/client-server-api/modules/end_to_end_encryption.md @@ -836,15 +836,15 @@ is the concatenation of: - The Device ID of the device which sent the `m.key.verification.start` message, followed by `|`. - The public key from the `m.key.verification.key` message sent by - the device which sent the `m.key.verification.start` message, - followed by `|`. + the device which sent the `m.key.verification.start` message, encoded as + unpadded base64, followed by `|`. - The Matrix ID of the user who sent the `m.key.verification.accept` message, followed by `|`. - The Device ID of the device which sent the `m.key.verification.accept` message, followed by `|`. - The public key from the `m.key.verification.key` message sent by - the device which sent the `m.key.verification.accept` message, - followed by `|`. + the device which sent the `m.key.verification.accept` message, encoded as + unpadded base64, followed by `|`. - The `transaction_id` being used. When the `key_agreement_protocol` is the deprecated method `curve25519`,