crypto: doc - AEAD API conversion

+-----------+                                    |

|           |            (1)

|   aead    | <-----------------------------------  esp_output

| (seqniv)  | ---+

|  (seqiv)  | ---+

+-----------+    |

                 | (2)

+-----------+    |

!Pinclude/linux/crypto.h Block Cipher Algorithm Definitions

!Finclude/linux/crypto.h crypto_alg

!Finclude/linux/crypto.h ablkcipher_alg

!Finclude/linux/crypto.h aead_alg

!Finclude/crypto/aead.h aead_alg

!Finclude/linux/crypto.h blkcipher_alg

!Finclude/linux/crypto.h cipher_alg

!Finclude/crypto/rng.h rng_alg

 * a breach in the integrity of the message. In essence, that -EBADMSG error

 * code is the key bonus an AEAD cipher has over "standard" block chaining

 * modes.

 *

 * Memory Structure:

 *

 * To support the needs of the most prominent user of AEAD ciphers, namely

 * IPSEC, the AEAD ciphers have a special memory layout the caller must adhere

 * to.

 *

 * The scatter list pointing to the input data must contain:

 *

 * * for RFC4106 ciphers, the concatenation of

 * associated authentication data || IV || plaintext or ciphertext. Note, the

 * same IV (buffer) is also set with the aead_request_set_crypt call. Note,

 * the API call of aead_request_set_ad must provide the length of the AAD and

 * the IV. The API call of aead_request_set_crypt only points to the size of

 * the input plaintext or ciphertext.

 *

 * * for "normal" AEAD ciphers, the concatenation of

 * associated authentication data || plaintext or ciphertext.

 *

 * It is important to note that if multiple scatter gather list entries form

 * the input data mentioned above, the first entry must not point to a NULL

 * buffer. If there is any potential where the AAD buffer can be NULL, the

 * calling code must contain a precaution to ensure that this does not result

 * in the first scatter gather list entry pointing to a NULL buffer.

 */

/**