Function to check if a string (password) can be found in online reverse sha1/md5 checksum dictionaries.

dictionary_attack_checker.sh

function checkmd5 {
	local string="${1?No string provided to test}"
	local checksum=$(printf "${string}" | md5sum | awk '{print $1}')

	printf "%10s: %s\n" "string" "${string}"
	printf "%10s: %s\n" "checksum" "${checksum}"
	printf "%10s: %s\n" "type" "MD5"
	printf "%10s: %s" "result" "Checking..."

	local result=$(reversemd5 "${checksum}")
	if [[ ${#result} -eq 0 ]]; then
		printf "\e[11D%s\033[K\n" "No match found"
		return
	fi
	
	printf "\e[11D%s\033[K\n" "${result}"
}

# sha1lookip 4233137d1c510f2e55ba5cb220b864b11033f156
function reversesha1 {
	# Check https://www.whatsmyip.org/hash-lookup/
	curl --silent  'https://www.whatsmyip.org/data/hash-lookup.php' \
	  -H 'Accept: */*' \
	  -H 'Accept-Language: en-US,en;q=0.9' \
	  -H 'Connection: keep-alive' \
	  -H 'Content-Type: application/x-www-form-urlencoded; charset=UTF-8' \
	  -H 'Origin: https://www.whatsmyip.org' \
	  -H 'Referer: https://www.whatsmyip.org/hash-lookup/' \
	  -H 'Sec-Fetch-Dest: empty' \
	  -H 'Sec-Fetch-Mode: cors' \
	  -H 'Sec-Fetch-Site: same-origin' \
	  -H 'Sec-GPC: 1' \
	  -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36' \
	  -H 'X-Requested-With: XMLHttpRequest' \
	  -H 'sec-ch-ua: "Not/A)Brand";v="8", "Chromium";v="126", "Brave";v="126"' \
	  -H 'sec-ch-ua-mobile: ?0' \
	  -H 'sec-ch-ua-platform: "macOS"' \
	  --data-raw "hash=${1?No checksum provided}" | cut -d\| -f2
}

function checksha1 {
	local string="${1?No string provided to test}"
	local checksum=$(printf "${string}" | sha1sum | awk '{print $1}')

	printf "%10s: %s\n" "string" "${string}"
	printf "%10s: %s\n" "checksum" "${checksum}"
	printf "%10s: %s\n" "type" "SHA1"
	printf "%10s: %s" "result" "Checking..."

	local result=$(reversesha1 "${checksum}")
	if [[ ${#result} -eq 0 ]]; then
		printf "\e[11D%s\e[K\n" "No match found"
		return
	fi
	printf "\e[11D%s\e[K\n" "${result}"
}

function reversechecksum {
	local string="${1?No string provided to test}"

	local md5_checksum=$(printf "${string}" | md5sum | awk '{print $1}')
	local sha1_checksum=$(printf "${string}" | sha1sum | awk '{print $1}')

	printf "%10s: %s\n" "string" "${string}"
	printf "%10s: %s\n" "md5sum" "${md5_checksum}"
	printf "%10s: %s\n" "sha1sum" "${sha1_checksum}"
	printf "%10s: %s" "result" "Checking..."

	local sha1_result=$(reversesha1 "${sha1_checksum}")
	local md5_result=$(reversemd5 "${md5_checksum}")

	if [[ ${#sha1_result} -eq 0 && ${#md5_result} -eq 0 ]]; then
		printf "\e[11D\e[32;1m%s\e[0m\e[K\n" "No matches found"
		return 1
	fi

	printf "\e[11D\e[31;1m%s\e[0m\e[K\n" "Matches found!"

	[[ ${#md5_result} -ne 0 ]] && 	printf "%10s: %s\n" "md5" "${md5_result}"
	[[ ${#sha1_result} -ne 0 ]] && 	printf "%10s: %s\n" "sha1" "${sha1_result}"

	return 0
}

# Examples:
# $ reversechecksum Hello123
#     string: Hello123
#     md5sum: d0aabe9a362cb2712ee90e04810902f3
#    sha1sum: 836babddc66080e01d52b8272aa9461c69ee0496
#     result: Matches found!
#        md5: Hello123
#       sha1: Hello123
# $ reversechecksum Hello123@*^\&
#     string: Hello123@*^&
#     md5sum: 2579dde733ae9276d3394ddf3f2ef812
#    sha1sum: 8722ab1569e3eb0eee741c4728f30e62c8131572
#     result: No matches found