Add name and alt attributes for all figures

Signed-off-by: David Runge <dave@sleepmap.de>
This commit is contained in:
David Runge 2023-11-20 16:23:25 +01:00
parent 514bb02d3d
commit 83a07f0001
No known key found for this signature in database
GPG key ID: 90D4B9641E092971
7 changed files with 53 additions and 10 deletions

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@ -101,6 +101,8 @@ A subkey binding signature binds a subkey to a primary key, and adds metadata in
(Note that subkeys that have the *signing* [key flag](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-12.html#name-key-flags) are a special case, and are handled slightly differently. See {numref}`bind_subkey_sign`.)
```{figure} diag/subkey_binding_signature.png
:name: fig-subkey-binding-signature
:alt: Depicts a diagram on white background with the title "Subkey binding signature". At the top left the symbol of a primary component key with certification capability is shown. At the bottom left the symbol of a component key with encryption capability is shown. The primary component key points at the lower component key with a full green arrow line. In the middle of the connection the small symbol of a signature packet is shown. On the right side of the diagram a detailed version of the signature packet can be found in a box with the title "Subkey binding signature". The text reads "Signature over Primary key, Subkey" and the box with "Signature metadata" contains the list "signature creation time", "key expiration time", "key flags" and "issuer fingerprint". The primary component key points at the detailed signature packet with a dotted green arrow line and the text "Primary key creates a subkey binding signature to bind the subkey to the primary key".
Linking an OpenPGP subkey to the primary key with a binding signature
```
@ -127,6 +129,8 @@ This is to prevent an attack where the attacker "adopts" the victims signing sub
In contrast to the [subkey binding signature](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-10.html#sigtype-subkey-binding) (type ID `0x18`), which is issued by the certificate's primary key, the [primary key binding signature](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-12.html#sigtype-primary-binding) (type ID `0x19`) is instead created by the subkey (informally also called an embedded "back signature").
```{figure} diag/subkey_binding_signatur_for_signing_sk.png
:name: fig-subkey-binding-signature-for-signing-subkeys
:alt: Depicts a diagram on white background with the title "Subkey binding signature for signing subkeys". At the top left the symbol of a primary component key with certification capability is shown. At the bottom left the symbol of a component key with signing capability is shown. The primary component key points at the lower component key with a full green arrow line. In the middle of the connection the small symbol of a signature packet is shown. On the right side of the diagram a detailed version of the signature packet can be found in a box with the title "Subkey binding signature". The text reads "Signature over Primary key, Subkey" and the box with "Signature metadata" in it contains the list "signature creation time", "key expiration time", "key flags" and "issuer fingerprint". Within the signature metadata a box with a green dotted frame extends the list with an inlined signature packet with the title "Embedded Signature; Primary key binding". Its inner text reads "Signature over Primary Key, Signing Subkey". The signature metadata area of this embedded signature holds the list "signature creation time" and "issuer fingerprint". The cryptographic signature symbol overlaps both metadata and general section of the embedded signature. From the signing component key a green dotted arrow line points to the embedded signature in the subkey binding signature with the text "Signing key creates a primary binding signature to associate itself with the primary key" ("primary binding signature" in bold). At the top of the diagram, the primary component key points at the detailed signature packet with a dotted green arrow line and the text "Primary key creates a subkey binding signature to bind the subkey to the primary key".
Linking an OpenPGP signing subkey to the primary key with a binding signature, and an embedded primary key binding signature
```
@ -149,6 +153,8 @@ Alice can link a User ID to her OpenPGP certificate with a cryptographic signatu
The resulting certifying self-signature packet is stored as part of the certificate, directly following the User ID packet.
```{figure} diag/user_id_certification.png
:name: fig-user-id-certification
:alt: Depicts a diagram on white background with the title "User ID binding signature". At the top left the symbol of a primary component key with certification capability is shown. At the bottom left the symbol of a User ID reads "Alice Adams <alice@example.org>". The primary component key points at the User ID with a full green arrow line. In the middle of the connection the small symbol of a signature packet is shown. On the right side of the diagram a detailed version of the signature packet can be found in a box with the title "User ID binding signature". The text reads "Signature over Primary key, User ID" and the box with "Signature metadata" in it contains the list "signature creation time", "key expiration time", "primary User ID flag", "algorithm preferences", "key expiration time (primary key)" and "key flags (primary key)". At the top of the diagram, the primary component key points at the detailed signature packet with a dotted green arrow line and the text "Primary key creates a User ID binding signature to associate the User ID with the primary key".
Linking a User ID to an OpenPGP certificate
```