How to substitute text from files in git history?

I'd recommend using the BFG Repo-Cleaner, a simpler, faster alternative to git-filter-branch specifically designed for rewriting files from Git history.

You should carefully follow these steps here: https://rtyley.github.io/bfg-repo-cleaner/#usage - but the core bit is just this: download the BFG's jar (requires Java 7 or above) and run this command:

$ java -jar bfg.jar  --replace-text replacements.txt -fi '*.php'  my-repo.git

The replacements.txt file should contain all the substitutions you want to do, in a format like this (one entry per line - note the comments shouldn't be included):

PASSWORD1 # Replace literal string 'PASSWORD1' with '***REMOVED***' (default)
PASSWORD2==>examplePass         # replace with 'examplePass' instead
PASSWORD3==>                    # replace with the empty string
regex:password=\w+==>password=  # Replace, using a regex
regex:\r(\n)==>$1               # Replace Windows newlines with Unix newlines

Your entire repository history will be scanned, and .php files (under 1MB in size) will have the substitutions performed: any matching string (that isn't in your latest commit) will be replaced.

Full disclosure: I'm the author of the BFG Repo-Cleaner.

You can avoid touching undesired files by passing -name "pattern" to find.

This works for me:

git filter-branch --tree-filter "find . -name '*.php' -exec sed -i -e \
    's/originalpassword/newpassword/g' {} \;"