Convert functions for IPFS CID v0 to 32 byte hex string and back

algosdk/util.py

@@ -2,6 +2,8 @@
 from . import encoding
 import decimal
 import base64
+import base58
+import binascii
 from nacl.signing import SigningKey, VerifyKey
 from nacl.exceptions import BadSignatureError
 from typing import Dict, Any
@@ -32,6 +34,39 @@ def algos_to_microalgos(algos):
     """
     return round(algos * constants.microalgos_to_algos_ratio)
 
+def ipfscidv0_to_byte32(cid):
+    """
+    Convert ipfscidv0 to 32 bytes hex string.
+
+    Args:
+        cid (string): IPFS CID Version 0
+
+    Returns:
+        str: 32 Bytes long string
+    """
+    """bytes32 is converted back into Ipfs hash format."""
+
+    decoded = base58.b58decode(cid)
+    sliced_decoded = decoded[2:]
+    return binascii.b2a_hex(sliced_decoded).decode("utf-8")
+
+
+def byte32_to_ipfscidv0(hexstr):
+    """
+    Convert 32 bytes hex string to ipfscidv0.
+
+    Args:
+        hexstr (string): 32 Bytes long string
+
+    Returns:
+        str: IPFS CID Version 0
+    """
+
+    binary_str = binascii.a2b_hex(hexstr)
+    completed_binary_str = b'\x12 ' + binary_str
+    return base58.b58encode(completed_binary_str).decode("utf-8")
+
+
 
 def sign_bytes(to_sign, private_key):
     """

setup.py

@@ -16,7 +16,7 @@
     project_urls={
         "Source": "https://github.com/algorand/py-algorand-sdk",
     },
-    install_requires=["pynacl", "pycryptodomex>=3.6.0", "msgpack"],
+    install_requires=["pynacl", "pycryptodomex>=3.6.0", "msgpack", "base58>=2.1.0"],
     packages=setuptools.find_packages(),
     python_requires=">=3.5",
     package_data={"": ["data/langspec.json"]},

test/steps/steps.py

@@ -626,6 +626,18 @@ def check_microalgos(context, microalgos):
     assert int(microalgos) == context.microalgos
 
 
+@when("I convert {ipfscid} ipfscid to bytes32 hex string and back")
+def convert_ipfscid(context, ipfscid):
+    context.ipfscid = util.byte32_to_ipfscidv0(
+        util.ipfscidv0_to_byte32(ipfscid)
+    )
+
+
+@then("it should still be the same ipfscid {ipfscid}")
+def check_ipfscid(context, ipfscid):
+    assert ipfscid == context.ipfscid
+
+
 @then("I get transactions by address and round")
 def txns_by_addr_round(context):
     txns = context.acl.transactions_by_address(