Digital Signature on Android

Digital Signature Service (DSS) 5.12.RC1 library port for android

Supported API Levels

Compatible with Android 8.0 (API level 26) to Android 13 (API level 33)

Features

Fully supports validation and signing for the following formats:

1. ASiC-E with CAdES
2. ASiC-E with XAdES
3. PAdES

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Integration

To include this port in your project, add the following to your build.gradle file:

repositories {
   maven {
      url = uri("https://maven.pkg.github.com/signerry/packages")
      credentials {
         username = System.getenv("GPR_USER")
         password = System.getenv("GPR_API_KEY")
      }
   }
}

dependencies {
    api "com.signerry.dss-android:dss-xades:1.01.20"
    api "com.signerry.dss-android:dss-asic-common:1.01.20"
    api "com.signerry.dss-android:dss-asic-xades:1.01.20"
    api "com.signerry.dss-android:dss-asic-cades:1.01.20"
}

• GPR_USER: Your GitHub username
• GPR_API_KEY: Your GitHub personal access token with read:packages scope

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Known Issues

Tests are performed for both unit and instrumented levels. Instrumented tests are executed on an Android emulator. All stock DSS tests pass with a few exceptions, mostly related to visual signatures. The following tests are not passing and have been disabled:

1. dss-xades:
   • XAdESLevelBEnvelopingManifestReferenceCanonicalizationTest
   • XAdESLevelBReSignOJManifestTest
2. dss-pades-pdfbox:
   • Visual textFullyTransparentTest
   • Visual multilinesWithDpiTest
   • Visual testWithCMYKImage
   • Visual rotationTest
3. dss-pades:
   • PAdESSignatureDigestRefPresenceTest (Same issue in stock DSS 5.12.RC1)
   • testDoubleSignature (Fails randomly due emulator to time shift issue)
4. dss-tsl-validation
   • skTLTest
5. dss-cades
   • CAdESMultipleCounterSignatureExtensionTest (Disabled due to expired timestamp)

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Substitutions

Because certain standard Java SDK functionalities are unavailable on Android, the following third-party libraries are used as substitutes:

Original Library/Functionality	Substitution
Apache PDFBox	PdfBox-Android
LDAP	UnboundID LDAP SDK
Java AWT	com.signerry:androidawt
javax.xml.bind	jakarta.xml.bind
org.apache.santuario:xmlsec	com.signerry.santuario:xmlsec
jaxb-ri	signerry-jaxb-ri

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Ported modules

This DSS project consists of several modules. The table below indicates which modules have been ported:

Module Name	Port status
dss-alert	✅
dss-asic-cades	✅
dss-asic-common	✅
dss-asic-xades	✅
dss-bom	❌
dss-cades	✅
dss-certificate-validation-common	❌
dss-certificate-validation-dto	❌
dss-certificate-validation-rest	❌
dss-certificate-validation-rest-client	❌
dss-certificate-validation-soap	❌
dss-certificate-validation-soap-client	❌
dss-common-remote-converter	❌
dss-common-remote-dto	❌
dss-cookbook	❌
dss-crl-parser	✅
dss-crl-parser-stream	✅
dss-crl-parser-x509crl	✅
dss-detailed-report-jaxb	✅
dss-diagnostic-jaxb	✅
dss-document	✅
dss-enumerations	✅
dss-i18n	✅
dss-jacoco-coverage	❌
dss-jades	❌
dss-jaxb-common	✅
dss-jaxb-parsers	✅
dss-model	✅
dss-pades	✅
dss-pades-openpdf	❌
dss-pades-pdfbox	✅
dss-pdfa	❌
dss-policy-jaxb	✅
dss-remote-services	❌
dss-rest-client	❌
dss-server-signing-common	❌
dss-server-signing-dto	❌
dss-server-signing-rest	❌
dss-server-signing-rest-client	❌
dss-server-signing-soap	❌
dss-server-signing-soap-client	❌
dss-service	✅
dss-signature-dto	❌
dss-signature-remote	❌
dss-signature-rest	❌
dss-signature-rest-client	❌
dss-signature-soap	❌
dss-signature-soap-client	❌
dss-simple-certificate-report-jaxb	✅
dss-simple-report-jaxb	✅
dss-spi	✅
dss-test	✅
dss-timestamp-dto	❌
dss-timestamp-remote	❌
dss-timestamp-remote-rest	❌
dss-timestamp-remote-rest-client	❌
dss-timestamp-remote-soap	❌
dss-timestamp-remote-soap-client	❌
dss-token	✅
dss-tsl-jaxb	❌
dss-tsl-validation	✅
dss-utils	✅
dss-utils-apache-commons	❌
dss-utils-google-guava	✅
dss-validation-dto	❌
dss-validation-rest	❌
dss-validation-rest-client	❌
dss-validation-server-common	❌
dss-validation-soap	❌
dss-validation-soap-client	❌
dss-xades	✅

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Demo Application

A sample signature validation application is available on the Google Play Store.

Simple report	Detailed report