diff -uNr a/ffa/MANIFEST.TXT b/ffa/MANIFEST.TXT
--- a/ffa/MANIFEST.TXT f744632a28817fdbb938352b58b697341fcd593afec07b8c22b5e332145a212bc0f19784d8b876ebad15446814191297b469733fa151750b4894129a23259278
+++ b/ffa/MANIFEST.TXT d35009b556cea183da0e80922a0a46907d16fb2486d4430808c6259a272c3402a298d41b00fc9a4157b4102e3480c13dfc8ee93ecf7e0cbe7644b6c5abf309e0
@@ -20,3 +20,4 @@
  578827 ffa_ch19_peh_tuning_and_demos  "Peh Tuning and Demo Tapes."
  611618 ffa_ch20_litmus                "A Peh-powered verifier for traditional GPG signatures."
  611775 ffa_ch20b_litmus_legacy_hashes "Support for certain ancient hash algos in Litmus."
+ 612395 ffa_ch20c_litmus_clearsigned   "Support for 'clearsigned' GPG texts in Litmus."
diff -uNr a/ffa/contrib/litmus/litmus.sh b/ffa/contrib/litmus/litmus.sh
--- a/ffa/contrib/litmus/litmus.sh e53145647493dd0343293f522c93fe9668147dd05b5ad4c3af763856126ed03bd6a53c51ed76ceb233678eb480e73175ada59af4a71a0d3da4fbc32392f2c5bd
+++ b/ffa/contrib/litmus/litmus.sh 11847537cdcdd430c43ab5e0d9ad598e7f7bfca1dedc7381128ede03c6515c2685ccab90672879eda73e6fe29b711eee3965421c4ad0866d7ae26df72a2ed197
@@ -5,8 +5,9 @@
 #                                                                          #
 # Usage: ./litmus.sh publickey.peh signature.sig datafile                  #
 #                                                                          #
-# Currently, supports only RSA 'detached' sigs made with the following     #
-# hashes: SHA1 (warns: known-breakable!), SHA224, SHA256, SHA384, SHA512.  #
+# Currently, supports RSA 'clearsigned' and 'detached' sigs made with the  #
+# following hashes:                                                        #
+# SHA1 (warns: known-breakable!), SHA224, SHA256, SHA384, SHA512.          #
 #                                                                          #
 # See instructions re: converting traditional GPG public keys for use with #
 # this program.                                                            #
@@ -27,8 +28,8 @@
 ############################################################################
 
 # External programs that are required (if not found, will eggog) :
-EXTERNALS="peh xxd hexdump base64 shasum cut tr sed wc grep printf"
-
+EXTERNALS="peh xxd hexdump base64 shasum cut tr sed wc grep printf 
+mktemp awk truncate"
 
 # Return Codes:
 
@@ -75,6 +76,12 @@
     exit $RET_EGGOG
 }
 
+# Malformed 'clearsigned' text file:
+eggog_broken_clearsigned() {
+        echo "$SIGFILE does not contain a clearsigned PGP message!" >&2
+        exit $RET_EGGOG
+}
+
 # Failure from bad Peh :
 eggog_peh() {
     echo "EGGOG in executing Peh tape! Please check Public Key." >&2
@@ -87,31 +94,59 @@
 }
 
 
-# Number of Arguments required by this program:
-REQD_ARGS=3
+# First argument is always the given public key file (a Peh tape, see docs)
+PUBFILE=$1
+
+# The given Detached GPG Signature file to be verified.
+# In 'clearsigned' mode, contains both signature and payload to be verified.
+SIGFILE=$2
 
-# If invalid arg count, print usage and abort:
-if [ "$#" -ne $REQD_ARGS ]; then
-    echo "Usage: $0 publickey.peh signature.sig datafile"
-    exit $RET_EGGOG
-fi
+# Get total number of arguments on command line:
+ARGCOUNT="$#"
+
+# On exit (if in 'clearsign' mode) :
+remove_temp_file() {
+    rm -f $DATAFILE
+}
+
+# Whether we are working on a 'clearsigned text'
+CLEARSIGN_MODE=false
+
+# Set up in the selected mode:
+case $ARGCOUNT in
+    2) # If given two arguments, verify a 'clearsigned' text file:
+        CLEARSIGN_MODE=true
+        # The processed payload will end up in a temporary file:
+        DATAFILE=$(mktemp) || { echo "Failed to create temp file!" >&2; \
+            exit $RET_EGGOG; }
+        # On exit, if in 'clearsign' mode, remove temporary file with payload:
+        trap remove_temp_file EXIT
+        # Expect 'Canonical Text Signature' in GPG sig packet turd
+        expect_sig_class=1
+        ;;
+    3) # Verify Detached Signature on given Data File (third argument is path):
+        # The given Data file to be verified against the Signature
+        DATAFILE=$3 # i.e. path given on command line
+        # Expect 'Detached Binary Signature' in GPG sig packet turd
+        expect_sig_class=0
+        ;;
+    *) # If invalid arg count -- print usage and abort:
+        echo "Usage: $0 publickey.peh signature.sig datafile"
+        echo "   or: $0 publickey.peh clearsigned.txt"
+        exit $RET_EGGOG
+        ;;
+esac
 
 
 # Minimal Peh Width (used for non-arithmetical ops, e.g. 'Owner')
 MIN_PEH_WIDTH=256
 
+# Peh data stack height for public key operations
+PEH_HEIGHT=3
+
 # Peh RNG (NOT USED in verifications, but needed to silence warning)
 PEH_RNG_DEV="/dev/random"
 
-# The given public key file (a Peh tape, see docs)
-PUBFILE=$1
-
-# The given Detached GPG Signature file to be verified
-SIGFILE=$2
-
-# The given Data file to be verified against the Signature
-DATAFILE=$3
-
 # Verify that each of the given input files exists:
 FILES=($PUBFILE $SIGFILE $DATAFILE)
 for f in ${FILES[@]}; do
@@ -185,7 +220,7 @@
 for i in $EXTERNALS
 do
     command -v $i >/dev/null && continue || \
-        { echo "$i is required but was not found! Please install it."; \
+        { echo "$i is required but was not found! Please install it." >&2 ; \
         exit $RET_EGGOG; }
 done
 
@@ -233,6 +268,54 @@
     eggog_sig_armour
 fi
 
+# If we are operating on a 'clearsigned' text file, $DATAFILE will be
+# an empty temporary file, and the payload is to be extracted to it,
+# with certain munges (see http://tools.ietf.org/html/rfc4880#section-7.1)
+if [ $CLEARSIGN_MODE == true ]
+then
+    # Find position of 'clearsign' payload start marker:
+    CLEAR_MARKER="\-\-\-\-\-BEGIN PGP SIGNED MESSAGE\-\-\-\-\-"
+    start_clr=$(grep -m 1 -n "$CLEAR_MARKER" $SIGFILE | cut -d ':' -f1)
+    
+    # If payload start marker was not found:
+    if [ "$start_clr" == "" ]
+    then
+        eggog_broken_clearsigned
+    fi
+    
+    # Discard the start marker:
+    start_clr=$(($start_clr + 1))
+    
+    # The payload ends with the line preceding the sig start:
+    end_clr=$((start_ln - 2))
+
+    # Find any 'Hash:' headers:
+    start_body=$(tail -n "+$start_clr" $SIGFILE | \
+        grep -v -n -m 1 "^Hash:" | cut -d ':' -f1)
+    
+    # Skip the above headers and mandatory empty line:
+    start_clr=$(($start_clr + $start_body))
+    
+    # If there is no payload, or the markers are misplaced, abort:
+    if [ $start_clr -ge $end_clr ]
+    then
+        eggog_broken_clearsigned
+    fi
+    
+    # Extract the 'clearsign' payload to the temporary file:
+    cat $SIGFILE | sed -n "$start_clr,$end_clr p" | \
+        sed 's/[ \t]*$//; s/^- //' | \
+        awk '{printf("%s\r\n",$0)}' \
+            > $DATAFILE
+    
+    # Remove the trailing CR,LF ending:
+    truncate -s -2 $DATAFILE
+    
+    # After this, proceed exactly like with 'detached' sigs, but
+    # with the expected 'class' being 1 rather than 0.
+fi
+
+
 # Number of bytes in the sig file
 sig_len=${#sig_bytes[@]}
 
@@ -300,11 +383,12 @@
 sig_version=$r
 sig_field_mandatory "Version" $sig_version 04
 
-# Class (only class 0 is supported)
+# Class (must be 'detached' or 'clearsign')
 get_sig_bytes 1
 turd+=$r
+hex_to_int
 sig_class=$r
-sig_field_mandatory "Class" $sig_class 00
+sig_field_mandatory "Class" $sig_class $expect_sig_class
 
 # Public Key Algo (only RSA is supported)
 get_sig_bytes 1
@@ -485,7 +569,7 @@
 tape=".$rsa_sig@Public-Op!.$pkcs={[Valid]QY}{[Invalid]QN}_"
 
 # Execute the tape:
-run_peh_tape $tape $rsa_width 3
+run_peh_tape $tape $rsa_width $PEH_HEIGHT
 
 # 'Belt and suspenders' -- test both output and return code:
 # If verification succeeded, return code will be 1, and output 'Valid':