ISO文件的完整性检查

下载了三个文件：
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.md5.asc
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.sha1.asc

熟悉一下gpg、md5sum、sha1sum：
# dpkg -S /usr/bin/gpg
gnupg: /usr/bin/gpg
# dpkg -S /usr/bin/md5sum
coreutils: /usr/bin/md5sum
# dpkg -S /usr/bin/sha1sum
coreutils: /usr/bin/sha1sum

# gpg KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.md5.asc
gpg: directory `/root/.gnupg' created
gpg: new configuration file `/root/.gnupg/gpg.conf' created
gpg: WARNING: options in `/root/.gnupg/gpg.conf' are not yet active during this run
gpg: keyring `/root/.gnupg/secring.gpg' created
gpg: keyring `/root/.gnupg/pubring.gpg' created
gpg: Signature made 2007年01月05日 星期五 11时15分26秒 CST using DSA key ID 57E37087
gpg: Can't check signature: public key not found

# rm *md5
#gpg --keyserver pgpkeys.mit.edu --recv-key 57E37087
gpg: requesting key 57E37087 from hkp server pgpkeys.mit.edu
gpg: key 57E37087: duplicated user ID detected - merged
gpg: /root/.gnupg/trustdb.gpg: trustdb created
gpg: key 57E37087: public key "Klaus Knopper " imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg:               imported: 1

# gpg K*o.md5.asc
gpg: Signature made 2007年01月05日 星期五 11时15分26秒 CST using DSA key ID 57E37087
gpg: Good signature from "Klaus Knopper "
gpg:                 aka "Klaus Knopper "
gpg:                 aka "Klaus Knopper "
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: 0E57 3DA0 F139 69EF 1DD5  ACAA 3798 E3D7 57E3 7087

# gpg K*o.sha1.asc
gpg: Signature made 2007年01月05日 星期五 11时15分45秒 CST using DSA key ID 57E37087
gpg: Good signature from "Klaus Knopper "
gpg:                 aka "Klaus Knopper "
gpg:                 aka "Klaus Knopper "
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: 0E57 3DA0 F139 69EF 1DD5  ACAA 3798 E3D7 57E3 7087

# ls K*
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso          KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.sha1
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.md5      KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.sha1.asc
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso.md5.asc

# md5sum -c *md5
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso: OK
# sha1sum -c *sha1
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso: OK