These are the official FreeBSD 5.4-RELEASE ISO images as downloaded from:
ftp://ftp2.freebsd.org/pub/FreeBSD/ISO-IMAGES-i386/5.4/

The MD5 hashes for these images are as follows:
MD5 (5.4-RELEASE-i386-bootonly.iso) = 2afe65af7e7b994c3ce87cefda27352e
MD5 (5.4-RELEASE-i386-disc1.iso) = 3dbb37485535e129354bc099e24aed99
MD5 (5.4-RELEASE-i386-disc2.iso) = e4b748415ca783fce64cfafd6bd56f57

Note: Most FreeBSD installs will only require disc 1 unless a large amount
of precompiled ports are selected during installation.