CVE-2020-13895: Improper Verification of Cryptographic Signature (CWE-347)
value: Crypt::Perl::ECDSA in the Crypt::Perl (aka p5-Crypt-Perl) module before 0.32 for Perl fails to verify correct ECDSA signatures when r and s are small and when s = 1. This happens when using the curve secp256r1 (prime256v1). This could conceivably have a security-relevant impact if an attacker wishes to use public r and s values when guessing whether signature verification will fail.
CWE description: The product does not verify, or incorrectly verifies, the cryptographic signature for data.
CVSS v3 base score: 8.8
Published: 2020-06-07T01:15Z
Repository: https://github.com/FGasper/p5-Crypt-Perl
Language: Other
Files changed: lib/Crypt/Perl/ECDSA/KeyBase.pm, t/google_wycheoproof.t
Commit date: 2020-06-04 08:27:02 -0400
Commit message: Fix ECDSA verify when r and s are small.

Issue #14 (Reported by Antonio de la Piedra)

Diff: diff --git a/lib/Crypt/Perl/ECDSA/KeyBase.pm b/lib/Crypt/Perl/ECDSA/KeyBase.pm
index b109026..b4a6cfc 100644
--- a/lib/Crypt/Perl/ECDSA/KeyBase.pm
+++ b/lib/Crypt/Perl/ECDSA/KeyBase.pm
@@ -214,10 +214,12 @@ sub _get_jwk_curve_name {
 }
 
 sub _verify {
     my ($self, $msg, $r, $s) = @_;
 
+    $_ = Crypt::Perl::BigInt->new($_) for ($r, $s);
+
     if ($r->is_positive() && $s->is_positive()) {
         my ($x, $y) = Crypt::Perl::ECDSA::Utils::split_G_or_public( $self->_decompress_public_point() );
         $_ = Crypt::Perl::BigInt->from_bytes($_) for ($x, $y);
 
         my $curve = $self->_get_curve_obj();
diff --git a/t/google_wycheoproof.t b/t/google_wycheoproof.t
new file mode 100644
index 0000000..bcdc1bf
--- /dev/null
+++ b/t/google_wycheoproof.t
@@ -0,0 +1,360 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+use Crypt::Perl::ECDSA;
+use Crypt::Perl::ECDSA::Generate;
+use Crypt::Perl::ECDSA::Parse;
+use Digest::SHA;
+use JSON;
+use Carp::Always;
+
+use Test::More;
+use Test::FailWarnings;
+
+my $file_content = <<'END';
+{
+  "algorithm" : "ECDSA",
+  "generatorVersion" : "0.8r12",
+  "numberOfTests" : 387,
+  "header" : [
+    "Test vectors of type EcdsaVerify are meant for the verification",
+    "of ASN encoded ECDSA signatures."
+  ],
+  "notes" : {
+    "BER" : "This is a signature with correct values for (r, s) but using some alternative BER encoding instead of DER encoding. Implementations should not accept such signatures to limit signature malleability.",
+    "EdgeCase" : "Edge case values such as r=1 and s=0 can lead to forgeries if the ECDSA implementation does not check boundaries and computes s^(-1)==0.",
+    "MissingZero" : "Some implementations of ECDSA and DSA incorrectly encode r and s by not including leading zeros in the ASN encoding of integers when necessary. Hence, some implementations (e.g. jdk) allow signatures with incorrect ASN encodings assuming that the signature is otherwise valid.",
+    "PointDuplication" : "Some implementations of ECDSA do not handle duplication and points at infinity correctly. This is a test vector that has been specially crafted to check for such an omission."
+  },
+  "schema" : "ecdsa_verify_schema.json",
+  "testGroups" : [
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "04a71af64de5126a4a4e02b7922d66ce9415ce88a4c9d25514d91082c8725ac9575d47723c8fbe580bb369fec9c2665d8e30a435b9932645482e7c9f11e872296b",
+        "wx" : "00a71af64de5126a4a4e02b7922d66ce9415ce88a4c9d25514d91082c8725ac957",
+        "wy" : "5d47723c8fbe580bb369fec9c2665d8e30a435b9932645482e7c9f11e872296b"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004a71af64de5126a4a4e02b7922d66ce9415ce88a4c9d25514d91082c8725ac9575d47723c8fbe580bb369fec9c2665d8e30a435b9932645482e7c9f11e872296b",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEpxr2TeUSakpOAreSLWbOlBXOiKTJ\n0lUU2RCCyHJayVddR3I8j75YC7Np/snCZl2OMKQ1uZMmRUgufJ8R6HIpaw==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 290,
+          "comment" : "small r and s",
+          "msg" : "313233343030",
+          "sig" : "3006020105020101",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "046627cec4f0731ea23fc2931f90ebe5b7572f597d20df08fc2b31ee8ef16b15726170ed77d8d0a14fc5c9c3c4c9be7f0d3ee18f709bb275eaf2073e258fe694a5",
+        "wx" : "6627cec4f0731ea23fc2931f90ebe5b7572f597d20df08fc2b31ee8ef16b1572",
+        "wy" : "6170ed77d8d0a14fc5c9c3c4c9be7f0d3ee18f709bb275eaf2073e258fe694a5"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200046627cec4f0731ea23fc2931f90ebe5b7572f597d20df08fc2b31ee8ef16b15726170ed77d8d0a14fc5c9c3c4c9be7f0d3ee18f709bb275eaf2073e258fe694a5",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEZifOxPBzHqI/wpMfkOvlt1cvWX0g\n3wj8KzHujvFrFXJhcO132NChT8XJw8TJvn8NPuGPcJuyderyBz4lj+aUpQ==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 291,
+          "comment" : "small r and s",
+          "msg" : "313233343030",
+          "sig" : "3006020105020103",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "045a7c8825e85691cce1f5e7544c54e73f14afc010cb731343262ca7ec5a77f5bfef6edf62a4497c1bd7b147fb6c3d22af3c39bfce95f30e13a16d3d7b2812f813",
+        "wx" : "5a7c8825e85691cce1f5e7544c54e73f14afc010cb731343262ca7ec5a77f5bf",
+        "wy" : "00ef6edf62a4497c1bd7b147fb6c3d22af3c39bfce95f30e13a16d3d7b2812f813"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200045a7c8825e85691cce1f5e7544c54e73f14afc010cb731343262ca7ec5a77f5bfef6edf62a4497c1bd7b147fb6c3d22af3c39bfce95f30e13a16d3d7b2812f813",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEWnyIJehWkczh9edUTFTnPxSvwBDL\ncxNDJiyn7Fp39b/vbt9ipEl8G9exR/tsPSKvPDm/zpXzDhOhbT17KBL4Ew==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 292,
+          "comment" : "small r and s",
+          "msg" : "313233343030",
+          "sig" : "3006020105020105",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "04cbe0c29132cd738364fedd603152990c048e5e2fff996d883fa6caca7978c73770af6a8ce44cb41224b2603606f4c04d188e80bff7cc31ad5189d4ab0d70e8c1",
+        "wx" : "00cbe0c29132cd738364fedd603152990c048e5e2fff996d883fa6caca7978c737",
+        "wy" : "70af6a8ce44cb41224b2603606f4c04d188e80bff7cc31ad5189d4ab0d70e8c1"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004cbe0c29132cd738364fedd603152990c048e5e2fff996d883fa6caca7978c73770af6a8ce44cb41224b2603606f4c04d188e80bff7cc31ad5189d4ab0d70e8c1",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEy+DCkTLNc4Nk/t1gMVKZDASOXi//\nmW2IP6bKynl4xzdwr2qM5Ey0EiSyYDYG9MBNGI6Av/fMMa1RidSrDXDowQ==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 293,
+          "comment" : "small r and s",
+          "msg" : "313233343030",
+          "sig" : "3006020105020106",
+          "result" : "valid",
+          "flags" : []
+        },
+        {
+          "tcId" : 294,
+          "comment" : "r is larger than n",
+          "msg" : "313233343030",
+          "sig" : "3026022100ffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632556020106",
+          "result" : "invalid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "044be4178097002f0deab68f0d9a130e0ed33a6795d02a20796db83444b037e13920f13051e0eecdcfce4dacea0f50d1f247caa669f193c1b4075b51ae296d2d56",
+        "wx" : "4be4178097002f0deab68f0d9a130e0ed33a6795d02a20796db83444b037e139",
+        "wy" : "20f13051e0eecdcfce4dacea0f50d1f247caa669f193c1b4075b51ae296d2d56"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200044be4178097002f0deab68f0d9a130e0ed33a6795d02a20796db83444b037e13920f13051e0eecdcfce4dacea0f50d1f247caa669f193c1b4075b51ae296d2d56",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAES+QXgJcALw3qto8NmhMODtM6Z5XQ\nKiB5bbg0RLA34Tkg8TBR4O7Nz85NrOoPUNHyR8qmafGTwbQHW1GuKW0tVg==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 295,
+          "comment" : "s is larger than n",
+          "msg" : "313233343030",
+          "sig" : "3026020105022100ffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc75fbd8",
+          "result" : "invalid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "04d0f73792203716afd4be4329faa48d269f15313ebbba379d7783c97bf3e890d9971f4a3206605bec21782bf5e275c714417e8f566549e6bc68690d2363c89cc1",
+        "wx" : "00d0f73792203716afd4be4329faa48d269f15313ebbba379d7783c97bf3e890d9",
+        "wy" : "00971f4a3206605bec21782bf5e275c714417e8f566549e6bc68690d2363c89cc1"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004d0f73792203716afd4be4329faa48d269f15313ebbba379d7783c97bf3e890d9971f4a3206605bec21782bf5e275c714417e8f566549e6bc68690d2363c89cc1",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE0Pc3kiA3Fq/UvkMp+qSNJp8VMT67\nujedd4PJe/PokNmXH0oyBmBb7CF4K/XidccUQX6PVmVJ5rxoaQ0jY8icwQ==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 296,
+          "comment" : "small r and s^-1",
+          "msg" : "313233343030",
+          "sig" : "3027020201000221008f1e3c7862c58b16bb76eddbb76eddbb516af4f63f2d74d76e0d28c9bb75ea88",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "044838b2be35a6276a80ef9e228140f9d9b96ce83b7a254f71ccdebbb8054ce05ffa9cbc123c919b19e00238198d04069043bd660a828814051fcb8aac738a6c6b",
+        "wx" : "4838b2be35a6276a80ef9e228140f9d9b96ce83b7a254f71ccdebbb8054ce05f",
+        "wy" : "00fa9cbc123c919b19e00238198d04069043bd660a828814051fcb8aac738a6c6b"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200044838b2be35a6276a80ef9e228140f9d9b96ce83b7a254f71ccdebbb8054ce05ffa9cbc123c919b19e00238198d04069043bd660a828814051fcb8aac738a6c6b",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAESDiyvjWmJ2qA754igUD52bls6Dt6\nJU9xzN67uAVM4F/6nLwSPJGbGeACOBmNBAaQQ71mCoKIFAUfy4qsc4psaw==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 297,
+          "comment" : "smallish r and s^-1",
+          "msg" : "313233343030",
+          "sig" : "302c02072d9b4d347952d6022100ef3043e7329581dbb3974497710ab11505ee1c87ff907beebadd195a0ffe6d7a",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "047393983ca30a520bbc4783dc9960746aab444ef520c0a8e771119aa4e74b0f64e9d7be1ab01a0bf626e709863e6a486dbaf32793afccf774e2c6cd27b1857526",
+        "wx" : "7393983ca30a520bbc4783dc9960746aab444ef520c0a8e771119aa4e74b0f64",
+        "wy" : "00e9d7be1ab01a0bf626e709863e6a486dbaf32793afccf774e2c6cd27b1857526"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200047393983ca30a520bbc4783dc9960746aab444ef520c0a8e771119aa4e74b0f64e9d7be1ab01a0bf626e709863e6a486dbaf32793afccf774e2c6cd27b1857526",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEc5OYPKMKUgu8R4PcmWB0aqtETvUg\nwKjncRGapOdLD2Tp174asBoL9ibnCYY+akhtuvMnk6/M93Tixs0nsYV1Jg==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 298,
+          "comment" : "100-bit r and small s^-1",
+          "msg" : "313233343030",
+          "sig" : "3032020d1033e67e37b32b445580bf4eff0221008b748b74000000008b748b748b748b7466e769ad4a16d3dcd87129b8e91d1b4d",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "045ac331a1103fe966697379f356a937f350588a05477e308851b8a502d5dfcdc5fe9993df4b57939b2b8da095bf6d794265204cfe03be995a02e65d408c871c0b",
+        "wx" : "5ac331a1103fe966697379f356a937f350588a05477e308851b8a502d5dfcdc5",
+        "wy" : "00fe9993df4b57939b2b8da095bf6d794265204cfe03be995a02e65d408c871c0b"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200045ac331a1103fe966697379f356a937f350588a05477e308851b8a502d5dfcdc5fe9993df4b57939b2b8da095bf6d794265204cfe03be995a02e65d408c871c0b",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEWsMxoRA/6WZpc3nzVqk381BYigVH\nfjCIUbilAtXfzcX+mZPfS1eTmyuNoJW/bXlCZSBM/gO+mVoC5l1AjIccCw==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 299,
+          "comment" : "small r and 100 bit s^-1",
+          "msg" : "313233343030",
+          "sig" : "302702020100022100ef9f6ba4d97c09d03178fa20b4aaad83be3cf9cb824a879fec3270fc4b81ef5b",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "041d209be8de2de877095a399d3904c74cc458d926e27bb8e58e5eae5767c41509dd59e04c214f7b18dce351fc2a549893a6860e80163f38cc60a4f2c9d040d8c9",
+        "wx" : "1d209be8de2de877095a399d3904c74cc458d926e27bb8e58e5eae5767c41509",
+        "wy" : "00dd59e04c214f7b18dce351fc2a549893a6860e80163f38cc60a4f2c9d040d8c9"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200041d209be8de2de877095a399d3904c74cc458d926e27bb8e58e5eae5767c41509dd59e04c214f7b18dce351fc2a549893a6860e80163f38cc60a4f2c9d040d8c9",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEHSCb6N4t6HcJWjmdOQTHTMRY2Sbi\ne7jljl6uV2fEFQndWeBMIU97GNzjUfwqVJiTpoYOgBY/OMxgpPLJ0EDYyQ==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 300,
+          "comment" : "100-bit r and s^-1",
+          "msg" : "313233343030",
+          "sig" : "3032020d062522bbd3ecbe7c39e93e7c25022100ef9f6ba4d97c09d03178fa20b4aaad83be3cf9cb824a879fec3270fc4b81ef5b",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "04083539fbee44625e3acaafa2fcb41349392cef0633a1b8fabecee0c133b10e99915c1ebe7bf00df8535196770a58047ae2a402f26326bb7d41d4d7616337911e",
+        "wx" : "083539fbee44625e3acaafa2fcb41349392cef0633a1b8fabecee0c133b10e99",
+        "wy" : "00915c1ebe7bf00df8535196770a58047ae2a402f26326bb7d41d4d7616337911e"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004083539fbee44625e3acaafa2fcb41349392cef0633a1b8fabecee0c133b10e99915c1ebe7bf00df8535196770a58047ae2a402f26326bb7d41d4d7616337911e",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAECDU5++5EYl46yq+i/LQTSTks7wYz\nobj6vs7gwTOxDpmRXB6+e/AN+FNRlncKWAR64qQC8mMmu31B1NdhYzeRHg==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 301,
+          "comment" : "r and s^-1 are close to n",
+          "msg" : "313233343030",
+          "sig" : "3045022100ffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc6324d50220555555550000000055555555555555553ef7a8e48d07df81a693439654210c70",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    },
+    {
+      "key" : {
+        "curve" : "secp256r1",
+        "keySize" : 256,
+        "type" : "EcPublicKey",
+        "uncompressed" : "048aeb368a7027a4d64abdea37390c0c1d6a26f399e2d9734de1eb3d0e1937387405bd13834715e1dbae9b875cf07bd55e1b6691c7f7536aef3b19bf7a4adf576d",
+        "wx" : "008aeb368a7027a4d64abdea37390c0c1d6a26f399e2d9734de1eb3d0e19373874",
+        "wy" : "05bd13834715e1dbae9b875cf07bd55e1b6691c7f7536aef3b19bf7a4adf576d"
+      },
+      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200048aeb368a7027a4d64abdea37390c0c1d6a26f399e2d9734de1eb3d0e1937387405bd13834715e1dbae9b875cf07bd55e1b6691c7f7536aef3b19bf7a4adf576d",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEius2inAnpNZKveo3OQwMHWom85ni\n2XNN4es9Dhk3OHQFvRODRxXh266bh1zwe9VeG2aRx/dTau87Gb96St9XbQ==\n-----END PUBLIC KEY-----",
+      "sha" : "SHA-256",
+      "type" : "EcdsaVerify",
+      "tests" : [
+        {
+          "tcId" : 302,
+          "comment" : "s == 1",
+          "msg" : "313233343030",
+          "sig" : "30250220555555550000000055555555555555553ef7a8e48d07df81a693439654210c70020101",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
+    }
+  ]
+}
+END
+
+my $json = JSON->new;
+my $data = $json->decode($file_content);
+
+
+diag "Parsing...";
+
+my $aref = $data->{testGroups};
+for my $element (@$aref) {
+    my $public = Crypt::Perl::ECDSA::Parse::public($element->{keyPem});
+    my $bref = $element->{tests};
+
+    for my $test (@$bref) {
+        my $msg_bytes = pack "H*", $test->{msg};
+        my $sig_bytes = pack "H*", $test->{sig};
+        my $hash = Digest::SHA::sha256($msg_bytes);
+
+            my $result = $public->verify($hash, $sig_bytes);
+
+            is(
+                $test->{result} eq "valid" || $test->{result} eq "acceptable",
+                !!$result,
+                "tcId: $test->{tcId}",
+            );
+
+    }
+}
+
+done_testing;

Fixed code:     $_ = Crypt::Perl::BigInt->new($_) for ($r, $s);

#!/usr/bin/env perl

use strict;
use warnings;

use Crypt::Perl::ECDSA;
use Crypt::Perl::ECDSA::Generate;
use Crypt::Perl::ECDSA::Parse;
use Digest::SHA;
use JSON;
use Carp::Always;

use Test::More;
use Test::FailWarnings;

my $file_content = <<'END';
{
  "algorithm" : "ECDSA",
  "generatorVersion" : "0.8r12",
  "numberOfTests" : 387,
  "header" : [
    "Test vectors of type EcdsaVerify are meant for the verification",
    "of ASN encoded ECDSA signatures."
  ],
  "notes" : {
    "BER" : "This is a signature with correct values for (r, s) but using some alternative BER encoding instead of DER encoding. Implementations should not accept such signatures to limit signature malleability.",
    "EdgeCase" : "Edge case values such as r=1 and s=0 can lead to forgeries if the ECDSA implementation does not check boundaries and computes s^(-1)==0.",
    "MissingZero" : "Some implementations of ECDSA and DSA incorrectly encode r and s by not including leading zeros in the ASN encoding of integers when necessary. Hence, some implementations (e.g. jdk) allow signatures with incorrect ASN encodings assuming that the signature is otherwise valid.",
    "PointDuplication" : "Some implementations of ECDSA do not handle duplication and points at infinity correctly. This is a test vector that has been specially crafted to check for such an omission."
  },
  "schema" : "ecdsa_verify_schema.json",
  "testGroups" : [
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "04a71af64de5126a4a4e02b7922d66ce9415ce88a4c9d25514d91082c8725ac9575d47723c8fbe580bb369fec9c2665d8e30a435b9932645482e7c9f11e872296b",
        "wx" : "00a71af64de5126a4a4e02b7922d66ce9415ce88a4c9d25514d91082c8725ac957",
        "wy" : "5d47723c8fbe580bb369fec9c2665d8e30a435b9932645482e7c9f11e872296b"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004a71af64de5126a4a4e02b7922d66ce9415ce88a4c9d25514d91082c8725ac9575d47723c8fbe580bb369fec9c2665d8e30a435b9932645482e7c9f11e872296b",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEpxr2TeUSakpOAreSLWbOlBXOiKTJ\n0lUU2RCCyHJayVddR3I8j75YC7Np/snCZl2OMKQ1uZMmRUgufJ8R6HIpaw==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 290,
          "comment" : "small r and s",
          "msg" : "313233343030",
          "sig" : "3006020105020101",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "046627cec4f0731ea23fc2931f90ebe5b7572f597d20df08fc2b31ee8ef16b15726170ed77d8d0a14fc5c9c3c4c9be7f0d3ee18f709bb275eaf2073e258fe694a5",
        "wx" : "6627cec4f0731ea23fc2931f90ebe5b7572f597d20df08fc2b31ee8ef16b1572",
        "wy" : "6170ed77d8d0a14fc5c9c3c4c9be7f0d3ee18f709bb275eaf2073e258fe694a5"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200046627cec4f0731ea23fc2931f90ebe5b7572f597d20df08fc2b31ee8ef16b15726170ed77d8d0a14fc5c9c3c4c9be7f0d3ee18f709bb275eaf2073e258fe694a5",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEZifOxPBzHqI/wpMfkOvlt1cvWX0g\n3wj8KzHujvFrFXJhcO132NChT8XJw8TJvn8NPuGPcJuyderyBz4lj+aUpQ==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 291,
          "comment" : "small r and s",
          "msg" : "313233343030",
          "sig" : "3006020105020103",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "045a7c8825e85691cce1f5e7544c54e73f14afc010cb731343262ca7ec5a77f5bfef6edf62a4497c1bd7b147fb6c3d22af3c39bfce95f30e13a16d3d7b2812f813",
        "wx" : "5a7c8825e85691cce1f5e7544c54e73f14afc010cb731343262ca7ec5a77f5bf",
        "wy" : "00ef6edf62a4497c1bd7b147fb6c3d22af3c39bfce95f30e13a16d3d7b2812f813"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200045a7c8825e85691cce1f5e7544c54e73f14afc010cb731343262ca7ec5a77f5bfef6edf62a4497c1bd7b147fb6c3d22af3c39bfce95f30e13a16d3d7b2812f813",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEWnyIJehWkczh9edUTFTnPxSvwBDL\ncxNDJiyn7Fp39b/vbt9ipEl8G9exR/tsPSKvPDm/zpXzDhOhbT17KBL4Ew==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 292,
          "comment" : "small r and s",
          "msg" : "313233343030",
          "sig" : "3006020105020105",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "04cbe0c29132cd738364fedd603152990c048e5e2fff996d883fa6caca7978c73770af6a8ce44cb41224b2603606f4c04d188e80bff7cc31ad5189d4ab0d70e8c1",
        "wx" : "00cbe0c29132cd738364fedd603152990c048e5e2fff996d883fa6caca7978c737",
        "wy" : "70af6a8ce44cb41224b2603606f4c04d188e80bff7cc31ad5189d4ab0d70e8c1"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004cbe0c29132cd738364fedd603152990c048e5e2fff996d883fa6caca7978c73770af6a8ce44cb41224b2603606f4c04d188e80bff7cc31ad5189d4ab0d70e8c1",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEy+DCkTLNc4Nk/t1gMVKZDASOXi//\nmW2IP6bKynl4xzdwr2qM5Ey0EiSyYDYG9MBNGI6Av/fMMa1RidSrDXDowQ==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 293,
          "comment" : "small r and s",
          "msg" : "313233343030",
          "sig" : "3006020105020106",
          "result" : "valid",
          "flags" : []
        },
        {
          "tcId" : 294,
          "comment" : "r is larger than n",
          "msg" : "313233343030",
          "sig" : "3026022100ffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632556020106",
          "result" : "invalid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "044be4178097002f0deab68f0d9a130e0ed33a6795d02a20796db83444b037e13920f13051e0eecdcfce4dacea0f50d1f247caa669f193c1b4075b51ae296d2d56",
        "wx" : "4be4178097002f0deab68f0d9a130e0ed33a6795d02a20796db83444b037e139",
        "wy" : "20f13051e0eecdcfce4dacea0f50d1f247caa669f193c1b4075b51ae296d2d56"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200044be4178097002f0deab68f0d9a130e0ed33a6795d02a20796db83444b037e13920f13051e0eecdcfce4dacea0f50d1f247caa669f193c1b4075b51ae296d2d56",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAES+QXgJcALw3qto8NmhMODtM6Z5XQ\nKiB5bbg0RLA34Tkg8TBR4O7Nz85NrOoPUNHyR8qmafGTwbQHW1GuKW0tVg==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 295,
          "comment" : "s is larger than n",
          "msg" : "313233343030",
          "sig" : "3026020105022100ffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc75fbd8",
          "result" : "invalid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "04d0f73792203716afd4be4329faa48d269f15313ebbba379d7783c97bf3e890d9971f4a3206605bec21782bf5e275c714417e8f566549e6bc68690d2363c89cc1",
        "wx" : "00d0f73792203716afd4be4329faa48d269f15313ebbba379d7783c97bf3e890d9",
        "wy" : "00971f4a3206605bec21782bf5e275c714417e8f566549e6bc68690d2363c89cc1"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004d0f73792203716afd4be4329faa48d269f15313ebbba379d7783c97bf3e890d9971f4a3206605bec21782bf5e275c714417e8f566549e6bc68690d2363c89cc1",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE0Pc3kiA3Fq/UvkMp+qSNJp8VMT67\nujedd4PJe/PokNmXH0oyBmBb7CF4K/XidccUQX6PVmVJ5rxoaQ0jY8icwQ==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 296,
          "comment" : "small r and s^-1",
          "msg" : "313233343030",
          "sig" : "3027020201000221008f1e3c7862c58b16bb76eddbb76eddbb516af4f63f2d74d76e0d28c9bb75ea88",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "044838b2be35a6276a80ef9e228140f9d9b96ce83b7a254f71ccdebbb8054ce05ffa9cbc123c919b19e00238198d04069043bd660a828814051fcb8aac738a6c6b",
        "wx" : "4838b2be35a6276a80ef9e228140f9d9b96ce83b7a254f71ccdebbb8054ce05f",
        "wy" : "00fa9cbc123c919b19e00238198d04069043bd660a828814051fcb8aac738a6c6b"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200044838b2be35a6276a80ef9e228140f9d9b96ce83b7a254f71ccdebbb8054ce05ffa9cbc123c919b19e00238198d04069043bd660a828814051fcb8aac738a6c6b",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAESDiyvjWmJ2qA754igUD52bls6Dt6\nJU9xzN67uAVM4F/6nLwSPJGbGeACOBmNBAaQQ71mCoKIFAUfy4qsc4psaw==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 297,
          "comment" : "smallish r and s^-1",
          "msg" : "313233343030",
          "sig" : "302c02072d9b4d347952d6022100ef3043e7329581dbb3974497710ab11505ee1c87ff907beebadd195a0ffe6d7a",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "047393983ca30a520bbc4783dc9960746aab444ef520c0a8e771119aa4e74b0f64e9d7be1ab01a0bf626e709863e6a486dbaf32793afccf774e2c6cd27b1857526",
        "wx" : "7393983ca30a520bbc4783dc9960746aab444ef520c0a8e771119aa4e74b0f64",
        "wy" : "00e9d7be1ab01a0bf626e709863e6a486dbaf32793afccf774e2c6cd27b1857526"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200047393983ca30a520bbc4783dc9960746aab444ef520c0a8e771119aa4e74b0f64e9d7be1ab01a0bf626e709863e6a486dbaf32793afccf774e2c6cd27b1857526",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEc5OYPKMKUgu8R4PcmWB0aqtETvUg\nwKjncRGapOdLD2Tp174asBoL9ibnCYY+akhtuvMnk6/M93Tixs0nsYV1Jg==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 298,
          "comment" : "100-bit r and small s^-1",
          "msg" : "313233343030",
          "sig" : "3032020d1033e67e37b32b445580bf4eff0221008b748b74000000008b748b748b748b7466e769ad4a16d3dcd87129b8e91d1b4d",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "045ac331a1103fe966697379f356a937f350588a05477e308851b8a502d5dfcdc5fe9993df4b57939b2b8da095bf6d794265204cfe03be995a02e65d408c871c0b",
        "wx" : "5ac331a1103fe966697379f356a937f350588a05477e308851b8a502d5dfcdc5",
        "wy" : "00fe9993df4b57939b2b8da095bf6d794265204cfe03be995a02e65d408c871c0b"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200045ac331a1103fe966697379f356a937f350588a05477e308851b8a502d5dfcdc5fe9993df4b57939b2b8da095bf6d794265204cfe03be995a02e65d408c871c0b",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEWsMxoRA/6WZpc3nzVqk381BYigVH\nfjCIUbilAtXfzcX+mZPfS1eTmyuNoJW/bXlCZSBM/gO+mVoC5l1AjIccCw==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 299,
          "comment" : "small r and 100 bit s^-1",
          "msg" : "313233343030",
          "sig" : "302702020100022100ef9f6ba4d97c09d03178fa20b4aaad83be3cf9cb824a879fec3270fc4b81ef5b",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "041d209be8de2de877095a399d3904c74cc458d926e27bb8e58e5eae5767c41509dd59e04c214f7b18dce351fc2a549893a6860e80163f38cc60a4f2c9d040d8c9",
        "wx" : "1d209be8de2de877095a399d3904c74cc458d926e27bb8e58e5eae5767c41509",
        "wy" : "00dd59e04c214f7b18dce351fc2a549893a6860e80163f38cc60a4f2c9d040d8c9"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200041d209be8de2de877095a399d3904c74cc458d926e27bb8e58e5eae5767c41509dd59e04c214f7b18dce351fc2a549893a6860e80163f38cc60a4f2c9d040d8c9",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEHSCb6N4t6HcJWjmdOQTHTMRY2Sbi\ne7jljl6uV2fEFQndWeBMIU97GNzjUfwqVJiTpoYOgBY/OMxgpPLJ0EDYyQ==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 300,
          "comment" : "100-bit r and s^-1",
          "msg" : "313233343030",
          "sig" : "3032020d062522bbd3ecbe7c39e93e7c25022100ef9f6ba4d97c09d03178fa20b4aaad83be3cf9cb824a879fec3270fc4b81ef5b",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "04083539fbee44625e3acaafa2fcb41349392cef0633a1b8fabecee0c133b10e99915c1ebe7bf00df8535196770a58047ae2a402f26326bb7d41d4d7616337911e",
        "wx" : "083539fbee44625e3acaafa2fcb41349392cef0633a1b8fabecee0c133b10e99",
        "wy" : "00915c1ebe7bf00df8535196770a58047ae2a402f26326bb7d41d4d7616337911e"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d03010703420004083539fbee44625e3acaafa2fcb41349392cef0633a1b8fabecee0c133b10e99915c1ebe7bf00df8535196770a58047ae2a402f26326bb7d41d4d7616337911e",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAECDU5++5EYl46yq+i/LQTSTks7wYz\nobj6vs7gwTOxDpmRXB6+e/AN+FNRlncKWAR64qQC8mMmu31B1NdhYzeRHg==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 301,
          "comment" : "r and s^-1 are close to n",
          "msg" : "313233343030",
          "sig" : "3045022100ffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc6324d50220555555550000000055555555555555553ef7a8e48d07df81a693439654210c70",
          "result" : "valid",
          "flags" : []
        }
      ]
    },
    {
      "key" : {
        "curve" : "secp256r1",
        "keySize" : 256,
        "type" : "EcPublicKey",
        "uncompressed" : "048aeb368a7027a4d64abdea37390c0c1d6a26f399e2d9734de1eb3d0e1937387405bd13834715e1dbae9b875cf07bd55e1b6691c7f7536aef3b19bf7a4adf576d",
        "wx" : "008aeb368a7027a4d64abdea37390c0c1d6a26f399e2d9734de1eb3d0e19373874",
        "wy" : "05bd13834715e1dbae9b875cf07bd55e1b6691c7f7536aef3b19bf7a4adf576d"
      },
      "keyDer" : "3059301306072a8648ce3d020106082a8648ce3d030107034200048aeb368a7027a4d64abdea37390c0c1d6a26f399e2d9734de1eb3d0e1937387405bd13834715e1dbae9b875cf07bd55e1b6691c7f7536aef3b19bf7a4adf576d",
      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEius2inAnpNZKveo3OQwMHWom85ni\n2XNN4es9Dhk3OHQFvRODRxXh266bh1zwe9VeG2aRx/dTau87Gb96St9XbQ==\n-----END PUBLIC KEY-----",
      "sha" : "SHA-256",
      "type" : "EcdsaVerify",
      "tests" : [
        {
          "tcId" : 302,
          "comment" : "s == 1",
          "msg" : "313233343030",
          "sig" : "30250220555555550000000055555555555555553ef7a8e48d07df81a693439654210c70020101",
          "result" : "valid",
          "flags" : []
        }
      ]
    }
  ]
}
END

my $json = JSON->new;
my $data = $json->decode($file_content);


diag "Parsing...";

my $aref = $data->{testGroups};
for my $element (@$aref) {
    my $public = Crypt::Perl::ECDSA::Parse::public($element->{keyPem});
    my $bref = $element->{tests};

    for my $test (@$bref) {
        my $msg_bytes = pack "H*", $test->{msg};
        my $sig_bytes = pack "H*", $test->{sig};
        my $hash = Digest::SHA::sha256($msg_bytes);

            my $result = $public->verify($hash, $sig_bytes);

            is(
                $test->{result} eq "valid" || $test->{result} eq "acceptable",
                !!$result,
                "tcId: $test->{tcId}",
            );

    }
}

done_testing;