`multicodec_codes.py` has incomplete hash code definitions

[sumanjeet0012]

multicodec_codes.py only defines 6 hash codes (identity, sha2-256, sha2-512, sha3-256, sha3-512, blake2b-256). Many commonly used hash functions are missing (shake-128, shake-256, keccak-, blake3, blake2s-, murmur3-*, etc.).

Problem

In dag/multicodec_codes.py:

SHA2_256_CODE = 0x12
SHA2_512_CODE = 0x13
SHA3_256_CODE = 0x16
SHA3_512_CODE = 0x17
BLAKE2B_256_CODE = 0xB220
IDENTITY_CODE = 0x00

Missing codes include:

• shake-128 (0x18), shake-256 (0x19)
• keccak-224 (0x1A), keccak-256 (0x1B), keccak-384 (0x1C), keccak-512 (0x1D)
• blake3 (0x1E)
• dbl-sha2-256 (0x56)
• sha2-224 (0x1013), sha2-384 (0x20)
• blake2b-8 through blake2b-512 (0xB201–0xB240)
• blake2s-8 through blake2s-256 (0xB241–0xB260)
• And many more...

Proposed Solution

Add all hash codes from the multicodec table. Consider importing from py-multihash constants instead of duplicating:

# Option 1: Import from py-multihash
from multihash.constants import HASH_CODES

# Option 2: Add missing codes manually
SHAKE_128_CODE = 0x18
SHAKE_256_CODE = 0x19
KECCAK_224_CODE = 0x1A
KECCAK_256_CODE = 0x1B
KECCAK_384_CODE = 0x1C
KECCAK_512_CODE = 0x1D
BLAKE3_CODE = 0x1E
# ... etc

Related

• Multicodec table: https://github.com/multiformats/multicodec/blob/master/table.csv
• File: dag/multicodec_codes.py