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ecdsa_verify/4

Module​

This predicate is provided by crypto.pl.

Load this module before using the predicate:

:- consult('/v1/lib/crypto.pl').

Description​

Succeeds when Signature is a valid ECDSA signature for Data and PubKey.

PubKey is the compressed public key as a list of bytes. Signature is the ASN.1 encoded signature as a list of bytes.

Options may be a single option term or a list of option terms:

  • type(+Algorithm) selects secp256r1 (default) or secp256k1;
  • encoding(+Encoding) selects how Data is interpreted, defaulting to hex.

Supported encodings are hex, octet, utf8, and text.

Signature​

ecdsa_verify(+PubKey, +Data, +Signature, +Options) is semidet

Examples​

Verify a secp256r1 signature with default options​

This scenario demonstrates how to verify an ECDSA signature over hexadecimal data.

Here are the steps of the scenario:

  • Given the program:
valid_secp256r1(Verified) :-
  hex_bytes('0213c8426be471e55506f7ce4f7df557a42e310df09f92eb732ca3085e797cef9b', PubKey),
  hex_bytes('30450220099e6f9dd218e0e304efa7a4224b0058a8e3aec73367ec239bee4ed8ed7d85db022100b504d3d0d2e879b04705c0e5a2b40b0521a5ab647ea207bd81134e1a4eb79e47', Signature),
  ecdsa_verify(PubKey, 'e50c26e89f734b2ee12041ff27874c901891f74a0f0cf470333312a3034ce3be', Signature, []),
  Verified = true.
  • Given the query:
consult('/v1/lib/crypto.pl'),
valid_secp256r1(Verified).
  • When the query is run
  • Then the answer we get is:
height: 42
gas_used: 246079
answer:
  has_more: false
  variables: ["Verified"]
  results:
  - substitutions:
    - variable: Verified
      expression: true

Verify a secp256k1 signature​

This scenario demonstrates how to select secp256k1 explicitly.

Here are the steps of the scenario:

  • Given the program:
valid_secp256k1(Verified) :-
  hex_bytes('026b5450187ee9c63ba9e42cb6018d8469c903aca116178e223de76e49fe63b71c', PubKey),
  hex_bytes('304402201448201bb4408549b0997f4b9ad9ed36f3cf8bb9c433fc7f3ba48c6b6e39476e022053f7d056f7ffeab9a79f3a36bc2ba969ddd530a3a1495d1ed7bba00039820223', Signature),
  ecdsa_verify(PubKey, 'dece063885d3648078f903b6a3e8989f649dc3368cd9c8d69755ed9dcb6a0995', Signature, [type(secp256k1)]),
  Verified = true.
  • Given the query:
consult('/v1/lib/crypto.pl'),
valid_secp256k1(Verified).
  • When the query is run
  • Then the answer we get is:
height: 42
gas_used: 250523
answer:
  has_more: false
  variables: ["Verified"]
  results:
  - substitutions:
    - variable: Verified
      expression: true

Verify ECDSA signatures with explicit algorithms​

This scenario demonstrates how to select both supported ECDSA algorithms explicitly.

Here are the steps of the scenario:

  • Given the program:
valid_explicit_secp256r1 :-
  hex_bytes('0213c8426be471e55506f7ce4f7df557a42e310df09f92eb732ca3085e797cef9b', PubKey),
  hex_bytes('30450220099e6f9dd218e0e304efa7a4224b0058a8e3aec73367ec239bee4ed8ed7d85db022100b504d3d0d2e879b04705c0e5a2b40b0521a5ab647ea207bd81134e1a4eb79e47', Signature),
  ecdsa_verify(PubKey, 'e50c26e89f734b2ee12041ff27874c901891f74a0f0cf470333312a3034ce3be', Signature, [type(secp256r1)]).

valid_explicit_secp256k1 :-
  hex_bytes('026b5450187ee9c63ba9e42cb6018d8469c903aca116178e223de76e49fe63b71c', PubKey),
  hex_bytes('304402201448201bb4408549b0997f4b9ad9ed36f3cf8bb9c433fc7f3ba48c6b6e39476e022053f7d056f7ffeab9a79f3a36bc2ba969ddd530a3a1495d1ed7bba00039820223', Signature),
  ecdsa_verify(PubKey, 'dece063885d3648078f903b6a3e8989f649dc3368cd9c8d69755ed9dcb6a0995', Signature, [type(secp256k1)]).
  • Given the query:
consult('/v1/lib/crypto.pl'),
valid_explicit_secp256r1,
valid_explicit_secp256k1,
Verified = true.
  • When the query is run
  • Then the answer we get is:
height: 42
gas_used: 493294
answer:
  has_more: false
  variables: ["Verified"]
  results:
  - substitutions:
    - variable: Verified
      expression: true

Reject an invalid ECDSA signature​

This scenario demonstrates that ecdsa_verify/4 fails when the signature does not match the data.

Here are the steps of the scenario:

  • Given the program:
invalid_secp256r1 :-
  hex_bytes('0213c8426be471e55506f7ce4f7df557a42e310df09f92eb732ca3085e797cef9b', PubKey),
  hex_bytes('30450220099e6f9dd218e0e304efa7a4224b0058a8e3aec73367ec239bee4ed8ed7d85db022100b504d3d0d2e879b04705c0e5a2b40b0521a5ab647ea207bd81134e1a4eb79e48', Signature),
  ecdsa_verify(PubKey, 'e50c26e89f734b2ee12041ff27874c901891f74a0f0cf470333312a3034ce3be', Signature, []).
  • Given the query:
consult('/v1/lib/crypto.pl'),
invalid_secp256r1.
  • When the query is run
  • Then the answer we get is:
height: 42
gas_used: 246047
answer:
  has_more: false
  variables:
  results:

Reject an unsupported ECDSA algorithm​

This scenario demonstrates that ecdsa_verify/4 rejects algorithms outside the ECDSA family.

Here are the steps of the scenario:

  • Given the program:
unsupported_ecdsa :-
  ecdsa_verify([], '', [], [type(ed25519)]).
  • Given the query:
consult('/v1/lib/crypto.pl'),
unsupported_ecdsa.
  • When the query is run
  • Then the answer we get is:
height: 42
gas_used: 4841
answer:
  has_more: false
  variables:
  results:
  - error: "error(type_error(cryptographic_algorithm,ed25519),ecdsa_verify/4)"
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