Talk:Apk spec: Difference between revisions

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- APK v2 package/index terminology
record                      A 512 byte sequence of bytes, a block
h                          Header record
d                          Data record
e1, e2                      Eof markers (two blocks 1024 bytes)
tar archive                A tar archive file, consiting of a set of files, a sequence of blocks ending with the eof marker blocks.
tar segment                A set of tar records, a sequence of tar records withouth a ending eof marker.
gzip stream                A stream is a sequence gzip compressed data, starting with a magic number, headers, body and an ending 8-byte trailer.
[ ... ]                    A gzip stream containing blocks
concatenate                To link togther things in a series or chain. ie. concatenate.
                            Concatenate 3 gzip streams sequentially in a file.
package signature          A single file that is a binary signature over the concatenated (control + data) gzip streams
package signature file      DigestRSA-PKCS1v15(SHA1( apk-gzip-stream-2 ++ apk-gzip-stream-3), DER)
index signature file        DigestRSA-PKCS1v15(SHA1( index-gzip-stream-2), DER)
h                          A tar header record block
h1                          Signature file header, permission 0644, uid 0 and gid 0.
C: checksum                The SHA1 hash of the "Control data" gzip stream (gzip stream 2)
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Revision as of 22:18, 4 December 2022

- APK v2 package/index terminology

record A 512 byte sequence of bytes, a block h Header record d Data record e1, e2 Eof markers (two blocks 1024 bytes) tar archive A tar archive file, consiting of a set of files, a sequence of blocks ending with the eof marker blocks. tar segment A set of tar records, a sequence of tar records withouth a ending eof marker. gzip stream A stream is a sequence gzip compressed data, starting with a magic number, headers, body and an ending 8-byte trailer. [ ... ] A gzip stream containing blocks concatenate To link togther things in a series or chain. ie. concatenate.

                           Concatenate 3 gzip streams sequentially in a file.

package signature A single file that is a binary signature over the concatenated (control + data) gzip streams package signature file DigestRSA-PKCS1v15(SHA1( apk-gzip-stream-2 ++ apk-gzip-stream-3), DER) index signature file DigestRSA-PKCS1v15(SHA1( index-gzip-stream-2), DER) h A tar header record block h1 Signature file header, permission 0644, uid 0 and gid 0. C: checksum The SHA1 hash of the "Control data" gzip stream (gzip stream 2)


APK v2 package layout
Gzip Streams apk-gzip-stream1 apk-gzip-stream2 apk-gzip-stream-3
Tar apk-tar-segment-1 apk-tar-segment-2 apk-tarball
Blocks [h1, d, ...] [h, d, ...] [h, d, h, d, ..., e1, e2 ]
Files Package Signature Control Data Package Data
Index v2 layout
Gzip Streams index-gzip-stream1 index-gzip-stream2
Tar index-tar-segment-1 index-tar-segment-2
Blocks [h1, d, ...] [h, d, ..., d1, d2]
Files Package Signature Description and APKINDEX