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Define the tag length in bits, like all other sizes
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Replace `tag_length` with `tag_length_bits` for clarity and
consistency.
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jedisct1 committed Dec 11, 2024
1 parent 990466f commit 884df11
Showing 1 changed file with 14 additions and 14 deletions.
28 changes: 14 additions & 14 deletions draft-irtf-cfrg-aegis-aead.md
Original file line number Diff line number Diff line change
Expand Up @@ -713,7 +713,7 @@ t = S2 ^ (LE64(ad_len_bits) || LE64(msg_len_bits))

Repeat(7, Update(t, t))

if tag_length == 16: # 128 bits
if tag_length_bits == 128:
tag = S0 ^ S1 ^ S2 ^ S3 ^ S4 ^ S5 ^ S6
else: # 256 bits
tag = (S0 ^ S1 ^ S2 ^ S3) || (S4 ^ S5 ^ S6 ^ S7)
Expand Down Expand Up @@ -1039,7 +1039,7 @@ t = S3 ^ (LE64(ad_len_bits) || LE64(msg_len_bits))

Repeat(7, Update(t))

if tag_length == 16: # 128 bits
if tag_length_bits == 128:
tag = S0 ^ S1 ^ S2 ^ S3 ^ S4 ^ S5
else: # 256 bits
tag = (S0 ^ S1 ^ S2) || (S3 ^ S4 ^ S5)
Expand Down Expand Up @@ -1325,7 +1325,7 @@ for i in 0..D:

Repeat(7, Update(t, t))

if tag_length == 16: # 128 bits
if tag_length_bits == 128:
tag = ZeroPad({}, 128)
for i in 0..D:
ti = V[0,i] ^ V[1,i] ^ V[2,i] ^ V[3,i] ^ V[4,i] ^ V[5,i] ^ V[6,i]
Expand Down Expand Up @@ -1532,7 +1532,7 @@ for i in 0..D:

Repeat(7, Update(t))

if tag_length == 16: # 128 bits
if tag_length_bits == 128:
tag = ZeroPad({}, 128)
for i in 0..D:
ti = V[0,i] ^ V[1,i] ^ V[2,i] ^ V[3,i] ^ V[4,i] ^ V[5,i]
Expand Down Expand Up @@ -1658,7 +1658,7 @@ Init(key, nonce)
data_blocks = Split(ZeroPad(data, 256), 256)
for di in data_blocks:
Absorb(di)
tag = Finalize(|data|, tag_length) # tag_length is 16 or 32
tag = Finalize(|data|, tag_length_bits)
return tag
~~~

Expand All @@ -1673,7 +1673,7 @@ Init(key, nonce)
data_blocks = Split(ZeroPad(data, 128), 128)
for di in data_blocks:
Absorb(di)
tag = Finalize(|data|, tag_length) # tag_length is 16 or 32
tag = Finalize(|data|, tag_length_bits)
return tag
~~~

Expand Down Expand Up @@ -1708,14 +1708,14 @@ Steps:

~~~
t = {}
u = LE64(data_len_bits) || LE64(tag_length * 8) # tag_length is 16 or 32
u = LE64(data_len_bits) || LE64(tag_length_bits)
for i in 0..D:
t = t || (V[2,i] ^ u)

Repeat(7, Update(t, t))

tags = {}
if tag_length == 16: # 128 bits
if tag_length_bits == 128:
for i in 0..D: # tag from state 0 is included
ti = V[0,i] ^ V[1,i] ^ V[2,i] ^ V[3,i] ^ V[4,i] ^ V[5,i] ^ V[6,i]
tags = tags || ti
Expand All @@ -1731,11 +1731,11 @@ if D > 1:
for v in Split(tags, 256):
Absorb(ZeroPad(v, R))

u = LE64(D) || LE64(tag_length * 8)
u = LE64(D) || LE64(tag_length_bits)
t = ZeroPad(V[2,0] ^ u, R)
Repeat(7, Update(t, t))

if tag_length == 16: # 128 bits
if tag_length_bits == 128:
tag = V[0,0] ^ V[1,0] ^ V[2,0] ^ V[3,0] ^ V[4,0] ^ V[5,0] ^ V[6,0]
else: # 256 bits
t0 = V[0,0] ^ V[1,0] ^ V[2,0] ^ V[3,0]
Expand Down Expand Up @@ -1772,14 +1772,14 @@ It finalizes all the instances, absorbs the resulting tags into the first state,

~~~
t = {}
u = LE64(data_len_bits) || LE64(tag_length * 8) # tag_length is 16 or 32
u = LE64(data_len_bits) || LE64(tag_length_bits)
for i in 0..D:
t = t || (V[3,i] ^ u)

Repeat(7, Update(t))

tags = {}
if tag_length == 16: # 128 bits
if tag_length_bits == 128:
for i in 1..D: # tag from state 0 is skipped
ti = V[0,i] ^ V[1,i] ^ V[2,i] ^ V[3,i] ^ V[4,i] ^ V[5,i]
tags = tags || ti
Expand All @@ -1795,11 +1795,11 @@ if D > 1:
for v in Split(tags, 128):
Absorb(ZeroPad(v, R))

u = LE64(D) || LE64(tag_length * 8)
u = LE64(D) || LE64(tag_length_bits)
t = ZeroPad(V[3,0] ^ u, R)
Repeat(7, Update(t))

if tag_length == 16: # 128 bits
if tag_length_bits == 128:
tag = V[0,0] ^ V[1,0] ^ V[2,0] ^ V[3,0] ^ V[4,0] ^ V[5,0] ^ V[6,0]
else: # 256 bits
t0 = V[0,0] ^ V[1,0] ^ V[2,0] ^ V[3,0]
Expand Down

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