Check integrity of Gpg4win packages
Usually you can use Microsoft's own methods to check that the installer is signed by one of the current code signing certificates listed below.
Microsoft will normally display the code signature in an user account control dialog when you try to execute the downloaded file; alternatively you can take a look in the file properties with the explorer.
Additional methods how to check the integrity can be found on the Wiki page on integrity checks.
Code Signing Certificate
The Gpg4win exe installer is signed with the following code signing certificate (since 2022):
S/N: 4F7382A39E57A34E167CF912 Issuer: CN=GlobalSign GCC R45 CodeSigning CA 2020,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F646540673130636F64652E636F6D,CN=g10 Code GmbH,O=g10 Code GmbH,L=Erkrath,ST=Nordrhein-Westfalen,C=DE sha2_fpr: DF:B5:9B:70:5C:47:9E:4E:FF:34:AD:BF:F9:B8:DC:AF:5F:74:D3:F6:58:91:F3:8C:D1:B1:0D:C8:D3:F1:42:20 sha1_fpr: B2:85:2D:44:90:F6:55:EB:EA:DF:9F:FD:8D:09:2E:81:54:45:00:77 certid: 6E9CA841CF00ABF4F8929210FF478C9CAB578518.4F7382A39E57A34E167CF912 keygrip: A340DB2D0B82943E8AFD854C6366D5953014D583 notBefore: 2022-04-08 08:26:24 notAfter: 2025-07-02 12:12:13
Previously used code signing certificates were:
S/N: 2F48FAE3C9E7B142B9A8B259 Issuer: CN=GlobalSign GCC R45 CodeSigning CA 2020,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F646540673130636F64652E636F6D,CN=g10 Code GmbH,O=g10 Code GmbH,L=Erkrath,ST=Nordrhein-Westfalen,C=DE sha2_fpr: B7:15:C7:C6:11:5A:99:A8:B1:C2:91:BE:68:90:BB:EE:AD:42:EE:2F:F6:17:78:E3:66:A0:1A:21:4E:FD:D8:00 sha1_fpr: 87:94:97:61:BE:B0:7B:FD:0B:90:F3:76:1F:1D:3E:3F:CC:3C:4D:B3 certid: 6E9CA841CF00ABF4F8929210FF478C9CAB578518.2F48FAE3C9E7B142B9A8B259 keygrip: 353A5BE748A8622E4D121DB3340A4EC1D4058BE1 notBefore: 2021-04-21 16:45:15 UTC notAfter: 2022-06-02 12:12:13 UTC S/N: 39E684F05C48911BAFB37629 Issuer: CN=GlobalSign CodeSigning CA - SHA256 - G3,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F646540673130636F64652E636F6D, CN=g10 Code GmbH,O=g10 Code GmbH,L=Erkrath,ST=Nordrhein-Westfalen,C=DE sha2_fpr: E0:4D:CD:E2:C9:EA:51:F3:34:63:CC:16:05:F2:9E:01:C2:84:F1:8F:ED:C8:E6:A6:42:05:EE:81:11:EF:BE:8C sha1_fpr: 42:DE:0F:25:84:8B:D2:E4:41:62:E1:BF:29:CD:97:0E:EB:70:F6:48 md5_fpr: 89:A8:7B:01:99:1B:74:AD:75:86:20:C3:AF:36:9E:76 notBefore: 2019-04-23 05:54:41 UTC notAfter: 2022-06-02 12:12:13 UTC S/N: 53F647D0F1DBA9E312A05669 Issuer: CN=GlobalSign CodeSigning CA - SHA256 - G3,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F64657369676E696E6740696E7465766174696F6E2E6465, CN=Intevation GmbH,O=Intevation GmbH,L=Osnabrueck,ST=Niedersachsen,C=DE sha1_fpr: C1:3A:65:96:3A:D5:3E:78:69:4D:D2:23:D5:18:00:77:91:A0:5F:E4 md5_fpr: 4C:AD:36:5A:30:06:B0:A3:6D:BB:1E:30:1E:44:4E:17 notBefore: 2019-03-13 12:15:07 notAfter: 2022-04-30 16:54:41 S/N: 1121A3D67EAB28AA86FD85728B57FA62630D Issuer: CN=GlobalSign CodeSigning CA - SHA256 - G2,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F64657369676E696E6740696E7465766174696F6E2E6465, CN=Intevation GmbH,O=Intevation GmbH,L=Osnabrueck,ST=Niedersachsen,C=DE sha1_fpr: DE:16:D5:97:2F:0B:73:95:F7:D9:1E:DC:1F:21:9B:0F:FE:89:FA:B3 md5_fpr: C0:98:08:94:D4:E7:97:3E:9D:F4:18:E4:5E:0A:2E:D7 notBefore: 2016-03-30 16:54:41 notAfter: 2019-03-31 16:54:41 S/N: 112117F638BDC993B761C6073D63C2F86EC4 Issuer: CN=GlobalSign CodeSigning CA - G2,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F64657369676E696E6740696E7465766174696F6E2E6465, CN=Intevation GmbH,O=Intevation GmbH,L=Osnabrueck,ST=Niedersachsen,C=DE sha1_fpr: 15:94:27:DA:C1:6E:68:A4:DD:47:EF:04:D2:17:C5:56:00:CF:A0:EC md5_fpr: 35:64:A0:D5:FC:6A:58:83:B8:C4:F7:1F:1C:F9:A6:9E notBefore: 2013-06-20 14:48:08 notAfter: 2016-09-10 09:27:26 S/N: 0100000000012A60AF8A8F Issuer: CN=GlobalSign ObjectSign CA,OU=ObjectSign CA,O=GlobalSign nv-sa,C=BE Subject: 1.2.840.113549.1.9.1=#636F64657369676E696E6740696E7465766174696F6E2E6465, CN=Intevation GmbH,O=Intevation GmbH,C=DE sha1_fpr: B4:71:26:90:F0:3A:69:1E:F0:75:3F:8D:11:C9:EA:C3:6D:FB:7C:92 md5_fpr: 80:0E:E2:F9:6F:AC:F4:16:0F:B2:AB:65:CA:82:22:55 notBefore: 2010-08-11 09:27:29 notAfter: 2013-08-11 09:27:26
SHA256 checksums
c3396b065cae3078ddd9f70899ae89ae21a02acdcd1667d32951f9060ea7d120 gpg4win-4.0.3.exe 8a67cfda81cadf05b09b10f4bfacb2dcd98743a508e3ef845bd65026b6267aa2 gpg4win-4.0.3.tar.bz2
SHA1 checksums
fd6d785c68f3f86f107f9cc02cd3fae84d3fd730 gpg4win-4.0.3.exe c85e62061729a7281d9e505e2ebc963e3e4a2807 gpg4win-4.0.3.tar.bz2
OpenPGP signatures
For gpg4win-4.0.3.exe:
https://files.gpg4win.org/gpg4win-4.0.3.exe.sig
For gpg4win-4.0.3.tar.bz2:
https://files.gpg4win.org/gpg4win-4.0.3.tar.bz2.sig
Since 2021 the signatures are created by one of the official GnuPG release keys (aka certificates) they can be obtained from the GnuPG Homepage or downloaded from public keyservers.
Previous public key (used up to 2021):
Intevation File Distribution Key
(Fingerprint: 13E3 CE81 AFEA 6F68 3E46 6E0D 42D8 7608 2688 DA1A)
Previous public key (used up to 2016):
Intevation File Distribution Key
(Fingerprint: 61AC 3F5E E4BE 593C 13D6 8B1E 7CBD 620B EC70 B1B8)
Checking the signature is best done via the File Explorer: Right click on the file and use GpgEX options -> verify.
File lengths
If you have a mismatch on the checksum or a bad signature you should first verify that you really downloaded the complete file. Here are the lengths you should get:
31078944 bytes for gpg4win-4.0.3.exe 203144191 bytes for gpg4win-4.0.3.tar.bz2