Signatures made by older versions of AGP cannot be copied by apksigcopier because the signing method differs too much from that used by apksigner (and signflinger in newer versions).
It is unlikely that support for these signatures will be added.
ZIP entry ordering differences
The v1 (JAR) signature files are always added at the end of the ZIP file by apksigner and apksigcopier; these older versions add them in a different position and sometimes the order of the ZIP entries in the central directory doesn't match the order of the entries in the file.
v1 (JAR) signature file differences
Some versions (e.g. 4.0.2) use create_version=2.4 (resulting in an Unsupported create_version error from apksigcopier) for the v1 signature files and leave an empty (i.e. w/o any entries, just the main headers) MANIFEST.MF in the unsigned APK.
The empty MANIFEST.MF is also present in the signed APK when using v2 signing only, whereas apksigner and apksigcopier always remove this file during signing/copying.
Affected versions
Versions <= 4.1.2 produce unsupported signatures, versions >= 4.2.2 seem to be unaffected.
Workaround: sign with apksigner
If upgrading to a newer version of AGP is not an option, you can build an unsigned APK and sign it with apksigner; only use of a signingConfig in build.gradle with one of these older versions produces unsupported signatures.
Workaround: use apksigner instead of signingConfig in build.gradle
Another workaround is to use apksigner instead of signingConfig in build.gradle; this allows keeping the exact same workflow, requiring only some small modifications to build.gradle.
Related: #80
Signatures made by older versions of AGP cannot be copied by
apksigcopierbecause the signing method differs too much from that used byapksigner(andsignflingerin newer versions).It is unlikely that support for these signatures will be added.
ZIP entry ordering differences
The v1 (JAR) signature files are always added at the end of the ZIP file by
apksignerandapksigcopier; these older versions add them in a different position and sometimes the order of the ZIP entries in the central directory doesn't match the order of the entries in the file.v1 (JAR) signature file differences
Some versions (e.g.
4.0.2) usecreate_version=2.4(resulting in anUnsupported create_versionerror fromapksigcopier) for the v1 signature files and leave an empty (i.e. w/o any entries, just the main headers)MANIFEST.MFin the unsigned APK.The empty
MANIFEST.MFis also present in the signed APK when using v2 signing only, whereasapksignerandapksigcopieralways remove this file during signing/copying.Affected versions
Versions <=
4.1.2produce unsupported signatures, versions >=4.2.2seem to be unaffected.Workaround: sign with apksigner
If upgrading to a newer version of AGP is not an option, you can build an unsigned APK and sign it with
apksigner; only use of asigningConfiginbuild.gradlewith one of these older versions produces unsupported signatures.Workaround: use apksigner instead of signingConfig in build.gradle
Another workaround is to use
apksignerinstead ofsigningConfiginbuild.gradle; this allows keeping the exact same workflow, requiring only some small modifications tobuild.gradle.Related: #80