commit 9cf1521775d2eda1df49c63bfe1485777efde945
Author: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Date:   Tue Apr 18 20:44:36 2017 +0100

    Hello world!

diff --git a/.hgignore b/.hgignore
new file mode 100644
index 00000000..a9d37c56
--- /dev/null
+++ b/.hgignore
@@ -0,0 +1,2 @@
+target
+Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 00000000..10c55dd5
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "xmpp-parsers"
+version = "0.1.0"
+authors = ["Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>"]
+
+[dependencies]
+minidom = "0.1.1"
diff --git a/src/data_forms.rs b/src/data_forms.rs
new file mode 100644
index 00000000..f4eb70c8
--- /dev/null
+++ b/src/data_forms.rs
@@ -0,0 +1,148 @@
+extern crate minidom;
+
+use std::str::FromStr;
+
+use minidom::Element;
+
+use error::Error;
+use ns::{DATA_FORMS_NS, MEDIA_ELEMENT_NS};
+
+use media_element::{MediaElement, parse_media_element};
+
+#[derive(Debug)]
+pub struct Field {
+    pub var: String,
+    pub type_: String, // TODO: use an enum here.
+    pub label: Option<String>,
+    pub values: Vec<String>,
+    pub media: Vec<MediaElement>,
+}
+
+#[derive(Debug, PartialEq)]
+pub enum DataFormType {
+    Cancel,
+    Form,
+    Result_,
+    Submit,
+}
+
+impl FromStr for DataFormType {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<DataFormType, Error> {
+        if s == "cancel" {
+            Ok(DataFormType::Cancel)
+        } else if s == "form" {
+            Ok(DataFormType::Form)
+        } else if s == "result" {
+            Ok(DataFormType::Result_)
+        } else if s == "submit" {
+            Ok(DataFormType::Submit)
+        } else {
+            Err(Error::ParseError("Unknown data form type."))
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct DataForm {
+    pub type_: DataFormType,
+    pub form_type: Option<String>,
+    pub fields: Vec<Field>,
+}
+
+pub fn parse_data_form(root: &Element) -> Result<DataForm, Error> {
+    assert!(root.is("x", DATA_FORMS_NS));
+    let type_: DataFormType = match root.attr("type") {
+        Some(type_) => type_.parse()?,
+        None => return Err(Error::ParseError("Type attribute on data form is mandatory.")),
+    };
+    let mut fields = vec!();
+    let mut form_type = None;
+    for field in root.children() {
+        if field.is("field", DATA_FORMS_NS) {
+            let var = field.attr("var").ok_or(Error::ParseError("Field must have a 'var' attribute."))?;
+            let field_type = field.attr("type").unwrap_or("text-single");
+            let label = field.attr("label").and_then(|label| label.parse().ok());
+            let mut values = vec!();
+            let mut media = vec!();
+            for element in field.children() {
+                if element.is("value", DATA_FORMS_NS) {
+                    values.push(element.text());
+                } else if element.is("media", MEDIA_ELEMENT_NS) {
+                    match parse_media_element(element) {
+                        Ok(media_element) => media.push(media_element),
+                        Err(_) => (), // TODO: is it really nice to swallow this error?
+                    }
+                } else {
+                    return Err(Error::ParseError("Field child isn’t a value or media element."));
+                }
+            }
+            if var == "FORM_TYPE" && field_type == "hidden" {
+                if form_type != None {
+                    return Err(Error::ParseError("More than one FORM_TYPE in a data form."));
+                }
+                if values.len() != 1 {
+                    return Err(Error::ParseError("Wrong number of values in FORM_TYPE."));
+                }
+                form_type = Some(values[0].clone());
+            }
+            fields.push(Field {
+                var: var.to_owned(),
+                type_: field_type.to_owned(),
+                label: label,
+                values: values,
+                media: media,
+            });
+        } else {
+            return Err(Error::ParseError("Unknown field type in data form."));
+        }
+    }
+    Ok(DataForm { type_: type_, form_type: form_type, fields: fields })
+}
+
+#[cfg(test)]
+mod tests {
+    use minidom::Element;
+    use error::Error;
+    use data_forms;
+
+    #[test]
+    fn test_simple() {
+        let elem: Element = "<x xmlns='jabber:x:data' type='result'/>".parse().unwrap();
+        let form = data_forms::parse_data_form(&elem).unwrap();
+        assert_eq!(form.type_, data_forms::DataFormType::Result_);
+        assert!(form.form_type.is_none());
+        assert!(form.fields.is_empty());
+    }
+
+    #[test]
+    fn test_invalid() {
+        let elem: Element = "<x xmlns='jabber:x:data'/>".parse().unwrap();
+        let error = data_forms::parse_data_form(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Type attribute on data form is mandatory.");
+
+        let elem: Element = "<x xmlns='jabber:x:data' type='coucou'/>".parse().unwrap();
+        let error = data_forms::parse_data_form(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Unknown data form type.");
+    }
+
+    #[test]
+    fn test_wrong_child() {
+        let elem: Element = "<x xmlns='jabber:x:data' type='cancel'><coucou/></x>".parse().unwrap();
+        let error = data_forms::parse_data_form(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Unknown field type in data form.");
+    }
+}
diff --git a/src/disco.rs b/src/disco.rs
new file mode 100644
index 00000000..7b2232ec
--- /dev/null
+++ b/src/disco.rs
@@ -0,0 +1,193 @@
+extern crate minidom;
+
+use minidom::Element;
+
+use error::Error;
+use ns::{DISCO_INFO_NS, DATA_FORMS_NS};
+
+use data_forms::{DataForm, DataFormType, parse_data_form};
+
+#[derive(Debug, Eq, PartialEq, Ord, PartialOrd)]
+pub struct Feature {
+    pub var: String,
+}
+
+#[derive(Debug)]
+pub struct Identity {
+    pub category: String, // TODO: use an enum here.
+    pub type_: String, // TODO: use an enum here.
+    pub xml_lang: String,
+    pub name: Option<String>,
+}
+
+#[derive(Debug)]
+pub struct Disco {
+    pub node: Option<String>,
+    pub identities: Vec<Identity>,
+    pub features: Vec<Feature>,
+    pub extensions: Vec<DataForm>,
+}
+
+pub fn parse_disco(root: &Element) -> Result<Disco, Error> {
+    assert!(root.is("query", DISCO_INFO_NS));
+    let mut identities: Vec<Identity> = vec!();
+    let mut features: Vec<Feature> = vec!();
+    let mut extensions: Vec<DataForm> = vec!();
+
+    let node = root.attr("node")
+                   .and_then(|node| node.parse().ok());
+
+    for child in root.children() {
+        if child.is("feature", DISCO_INFO_NS) {
+            let feature = child.attr("var")
+                               .ok_or(Error::ParseError("Feature must have a 'var' attribute."))?;
+            features.push(Feature {
+                var: feature.to_owned(),
+            });
+        } else if child.is("identity", DISCO_INFO_NS) {
+            let category = child.attr("category")
+                                .ok_or(Error::ParseError("Identity must have a 'category' attribute."))?;
+            if category == "" {
+                return Err(Error::ParseError("Identity must have a non-empty 'category' attribute."))
+            }
+
+            let type_ = child.attr("type")
+                             .ok_or(Error::ParseError("Identity must have a 'type' attribute."))?;
+            if type_ == "" {
+                return Err(Error::ParseError("Identity must have a non-empty 'type' attribute."))
+            }
+
+            // TODO: this must check for the namespace of the attribute, but minidom doesn’t support that yet, see issue #2.
+            let xml_lang = child.attr("lang").unwrap_or("");
+            let name = child.attr("name")
+                            .and_then(|node| node.parse().ok());
+            identities.push(Identity {
+                category: category.to_owned(),
+                type_: type_.to_owned(),
+                xml_lang: xml_lang.to_owned(),
+                name: name,
+            });
+        } else if child.is("x", DATA_FORMS_NS) {
+            let data_form = parse_data_form(child)?;
+            match data_form.type_ {
+                DataFormType::Result_ => (),
+                _ => return Err(Error::ParseError("Data form must have a 'result' type in disco#info.")),
+            }
+            match data_form.form_type {
+                Some(_) => extensions.push(data_form),
+                None => return Err(Error::ParseError("Data form found without a FORM_TYPE.")),
+            }
+        } else {
+            return Err(Error::ParseError("Unknown element in disco#info."));
+        }
+    }
+
+    if identities.is_empty() {
+        return Err(Error::ParseError("There must be at least one identity in disco#info."));
+    }
+    if features.is_empty() {
+        return Err(Error::ParseError("There must be at least one feature in disco#info."));
+    }
+    if !features.contains(&Feature { var: DISCO_INFO_NS.to_owned() }) {
+        return Err(Error::ParseError("disco#info feature not present in disco#info."));
+    }
+
+    return Ok(Disco {
+        node: node,
+        identities: identities,
+        features: features,
+        extensions: extensions
+    });
+}
+
+#[cfg(test)]
+mod tests {
+    use minidom::Element;
+    use error::Error;
+    use disco;
+
+    #[test]
+    fn test_simple() {
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category='client' type='pc'/><feature var='http://jabber.org/protocol/disco#info'/></query>".parse().unwrap();
+        let query = disco::parse_disco(&elem).unwrap();
+        assert!(query.node.is_none());
+        assert_eq!(query.identities.len(), 1);
+        assert_eq!(query.features.len(), 1);
+        assert!(query.extensions.is_empty());
+    }
+
+    #[test]
+    fn test_invalid() {
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><coucou/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Unknown element in disco#info.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'/>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "There must be at least one identity in disco#info.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Identity must have a 'category' attribute.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category=''/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Identity must have a non-empty 'category' attribute.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category='coucou'/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Identity must have a 'type' attribute.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category='coucou' type=''/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Identity must have a non-empty 'type' attribute.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><feature/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Feature must have a 'var' attribute.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category='client' type='pc'/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "There must be at least one feature in disco#info.");
+
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category='client' type='pc'/><feature var='http://jabber.org/protocol/disco#items'/></query>".parse().unwrap();
+        let error = disco::parse_disco(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "disco#info feature not present in disco#info.");
+    }
+}
diff --git a/src/ecaps2.rs b/src/ecaps2.rs
new file mode 100644
index 00000000..50b94128
--- /dev/null
+++ b/src/ecaps2.rs
@@ -0,0 +1,330 @@
+extern crate minidom;
+
+use minidom::Element;
+
+use error::Error;
+
+use disco::{Feature, Identity, Disco, parse_disco};
+use data_forms::DataForm;
+
+fn compute_item(field: String) -> Vec<u8> {
+    let mut bytes = field.as_bytes().to_vec();
+    bytes.push(0x1f);
+    bytes
+}
+
+fn compute_items<T, F: Fn(T) -> Vec<u8>>(things: Vec<T>, separator: u8, encode: F) -> Vec<u8> {
+    let mut string: Vec<u8> = vec!();
+    let mut accumulator: Vec<Vec<u8>> = vec!();
+    for thing in things {
+        let bytes = encode(thing);
+        accumulator.push(bytes);
+    }
+    // This works using the expected i;octet collation.
+    accumulator.sort();
+    for mut bytes in accumulator {
+        string.append(&mut bytes);
+    }
+    string.push(separator);
+    string
+}
+
+fn compute_features(features: Vec<Feature>) -> Vec<u8> {
+    compute_items(features, 0x1c, |feature| compute_item(feature.var))
+}
+
+fn compute_identities(identities: Vec<Identity>) -> Vec<u8> {
+    compute_items(identities, 0x1c, |identity| {
+        let mut bytes = compute_item(identity.category);
+        bytes.append(&mut compute_item(identity.type_));
+        bytes.append(&mut compute_item(identity.xml_lang));
+        bytes.append(&mut compute_item(identity.name.unwrap_or(String::new())));
+        bytes.push(0x1e);
+        bytes
+    })
+}
+
+fn compute_extensions(extensions: Vec<DataForm>) -> Vec<u8> {
+    compute_items(extensions, 0x1c, |extension| {
+        compute_items(extension.fields, 0x1d, |field| {
+            let mut bytes = compute_item(field.var);
+            bytes.append(&mut compute_items(field.values, 0x1e,
+                                            |value| compute_item(value)));
+            bytes
+        })
+    })
+}
+
+fn compute_disco(disco: Disco) -> Vec<u8> {
+    let features_string = compute_features(disco.features);
+    let identities_string = compute_identities(disco.identities);
+    let extensions_string = compute_extensions(disco.extensions);
+
+    let mut final_string = vec!();
+    final_string.extend(features_string);
+    final_string.extend(identities_string);
+    final_string.extend(extensions_string);
+    final_string
+}
+
+pub fn convert_element(root: &Element) -> Result<Vec<u8>, Error> {
+    let disco = parse_disco(root)?;
+    let final_string = compute_disco(disco);
+    Ok(final_string)
+}
+
+#[cfg(test)]
+mod tests {
+    use minidom::Element;
+    use ecaps2;
+
+    #[test]
+    fn test_simple() {
+        let elem: Element = "<query xmlns='http://jabber.org/protocol/disco#info'><identity category='client' type='pc'/><feature var='http://jabber.org/protocol/disco#info'/></query>".parse().unwrap();
+        let ecaps2 = ecaps2::convert_element(&elem).unwrap();
+        assert_eq!(ecaps2.len(), 54);
+    }
+
+    #[test]
+    fn test_xep_ex1() {
+        let elem: Element = r#"
+<query xmlns="http://jabber.org/protocol/disco#info">
+  <identity category="client" name="BombusMod" type="mobile"/>
+  <feature var="http://jabber.org/protocol/si"/>
+  <feature var="http://jabber.org/protocol/bytestreams"/>
+  <feature var="http://jabber.org/protocol/chatstates"/>
+  <feature var="http://jabber.org/protocol/disco#info"/>
+  <feature var="http://jabber.org/protocol/disco#items"/>
+  <feature var="urn:xmpp:ping"/>
+  <feature var="jabber:iq:time"/>
+  <feature var="jabber:iq:privacy"/>
+  <feature var="jabber:iq:version"/>
+  <feature var="http://jabber.org/protocol/rosterx"/>
+  <feature var="urn:xmpp:time"/>
+  <feature var="jabber:x:oob"/>
+  <feature var="http://jabber.org/protocol/ibb"/>
+  <feature var="http://jabber.org/protocol/si/profile/file-transfer"/>
+  <feature var="urn:xmpp:receipts"/>
+  <feature var="jabber:iq:roster"/>
+  <feature var="jabber:iq:last"/>
+</query>
+"#.parse().unwrap();
+        let expected = vec![104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98,
+            101, 114, 46, 111, 114, 103, 47, 112, 114, 111, 116, 111, 99, 111,
+            108, 47, 98, 121, 116, 101, 115, 116, 114, 101, 97, 109, 115, 31,
+            104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111,
+            114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 99, 104,
+            97, 116, 115, 116, 97, 116, 101, 115, 31, 104, 116, 116, 112, 58,
+            47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114,
+            111, 116, 111, 99, 111, 108, 47, 100, 105, 115, 99, 111, 35, 105,
+            110, 102, 111, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98,
+            101, 114, 46, 111, 114, 103, 47, 112, 114, 111, 116, 111, 99, 111,
+            108, 47, 100, 105, 115, 99, 111, 35, 105, 116, 101, 109, 115, 31,
+            104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111,
+            114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 105, 98,
+            98, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114,
+            46, 111, 114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47,
+            114, 111, 115, 116, 101, 114, 120, 31, 104, 116, 116, 112, 58, 47,
+            47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114,
+            111, 116, 111, 99, 111, 108, 47, 115, 105, 31, 104, 116, 116, 112,
+            58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112,
+            114, 111, 116, 111, 99, 111, 108, 47, 115, 105, 47, 112, 114, 111,
+            102, 105, 108, 101, 47, 102, 105, 108, 101, 45, 116, 114, 97, 110,
+            115, 102, 101, 114, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113,
+            58, 108, 97, 115, 116, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113,
+            58, 112, 114, 105, 118, 97, 99, 121, 31, 106, 97, 98, 98, 101, 114,
+            58, 105, 113, 58, 114, 111, 115, 116, 101, 114, 31, 106, 97, 98,
+            98, 101, 114, 58, 105, 113, 58, 116, 105, 109, 101, 31, 106, 97,
+            98, 98, 101, 114, 58, 105, 113, 58, 118, 101, 114, 115, 105, 111,
+            110, 31, 106, 97, 98, 98, 101, 114, 58, 120, 58, 111, 111, 98, 31,
+            117, 114, 110, 58, 120, 109, 112, 112, 58, 112, 105, 110, 103, 31,
+            117, 114, 110, 58, 120, 109, 112, 112, 58, 114, 101, 99, 101, 105,
+            112, 116, 115, 31, 117, 114, 110, 58, 120, 109, 112, 112, 58, 116,
+            105, 109, 101, 31, 28, 99, 108, 105, 101, 110, 116, 31, 109, 111,
+            98, 105, 108, 101, 31, 31, 66, 111, 109, 98, 117, 115, 77, 111,
+            100, 31, 30, 28, 28];
+        let ecaps2 = ecaps2::convert_element(&elem).unwrap();
+        assert_eq!(ecaps2.len(), 0x1d9);
+        assert_eq!(ecaps2, expected);
+
+        /*
+        let sha_256 = hash(ecaps2, "sha-256");
+        assert_eq!(sha_256, "kzBZbkqJ3ADrj7v08reD1qcWUwNGHaidNUgD7nHpiw8=");
+        let sha3_256 = hash(ecaps2, "sha3-256");
+        assert_eq!(sha3_256, "79mdYAfU9rEdTOcWDO7UEAt6E56SUzk/g6TnqUeuD9Q=");
+        */
+    }
+
+    #[test]
+    fn test_xep_ex2() {
+        let elem: Element = r#"
+<query xmlns="http://jabber.org/protocol/disco#info">
+  <identity category="client" name="Tkabber" type="pc" xml:lang="en"/>
+  <identity category="client" name="Ткаббер" type="pc" xml:lang="ru"/>
+  <feature var="games:board"/>
+  <feature var="http://jabber.org/protocol/activity"/>
+  <feature var="http://jabber.org/protocol/activity+notify"/>
+  <feature var="http://jabber.org/protocol/bytestreams"/>
+  <feature var="http://jabber.org/protocol/chatstates"/>
+  <feature var="http://jabber.org/protocol/commands"/>
+  <feature var="http://jabber.org/protocol/disco#info"/>
+  <feature var="http://jabber.org/protocol/disco#items"/>
+  <feature var="http://jabber.org/protocol/evil"/>
+  <feature var="http://jabber.org/protocol/feature-neg"/>
+  <feature var="http://jabber.org/protocol/geoloc"/>
+  <feature var="http://jabber.org/protocol/geoloc+notify"/>
+  <feature var="http://jabber.org/protocol/ibb"/>
+  <feature var="http://jabber.org/protocol/iqibb"/>
+  <feature var="http://jabber.org/protocol/mood"/>
+  <feature var="http://jabber.org/protocol/mood+notify"/>
+  <feature var="http://jabber.org/protocol/rosterx"/>
+  <feature var="http://jabber.org/protocol/si"/>
+  <feature var="http://jabber.org/protocol/si/profile/file-transfer"/>
+  <feature var="http://jabber.org/protocol/tune"/>
+  <feature var="http://www.facebook.com/xmpp/messages"/>
+  <feature var="http://www.xmpp.org/extensions/xep-0084.html#ns-metadata+notify"/>
+  <feature var="jabber:iq:avatar"/>
+  <feature var="jabber:iq:browse"/>
+  <feature var="jabber:iq:dtcp"/>
+  <feature var="jabber:iq:filexfer"/>
+  <feature var="jabber:iq:ibb"/>
+  <feature var="jabber:iq:inband"/>
+  <feature var="jabber:iq:jidlink"/>
+  <feature var="jabber:iq:last"/>
+  <feature var="jabber:iq:oob"/>
+  <feature var="jabber:iq:privacy"/>
+  <feature var="jabber:iq:roster"/>
+  <feature var="jabber:iq:time"/>
+  <feature var="jabber:iq:version"/>
+  <feature var="jabber:x:data"/>
+  <feature var="jabber:x:event"/>
+  <feature var="jabber:x:oob"/>
+  <feature var="urn:xmpp:avatar:metadata+notify"/>
+  <feature var="urn:xmpp:ping"/>
+  <feature var="urn:xmpp:receipts"/>
+  <feature var="urn:xmpp:time"/>
+  <x xmlns="jabber:x:data" type="result">
+    <field type="hidden" var="FORM_TYPE">
+      <value>urn:xmpp:dataforms:softwareinfo</value>
+    </field>
+    <field var="software">
+      <value>Tkabber</value>
+    </field>
+    <field var="software_version">
+      <value>0.11.1-svn-20111216-mod (Tcl/Tk 8.6b2)</value>
+    </field>
+    <field var="os">
+      <value>Windows</value>
+    </field>
+    <field var="os_version">
+      <value>XP</value>
+    </field>
+  </x>
+</query>
+"#.parse().unwrap();
+        let expected = vec![103, 97, 109, 101, 115, 58, 98, 111, 97, 114, 100,
+            31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46,
+            111, 114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 97,
+            99, 116, 105, 118, 105, 116, 121, 31, 104, 116, 116, 112, 58, 47,
+            47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114,
+            111, 116, 111, 99, 111, 108, 47, 97, 99, 116, 105, 118, 105, 116,
+            121, 43, 110, 111, 116, 105, 102, 121, 31, 104, 116, 116, 112, 58,
+            47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114,
+            111, 116, 111, 99, 111, 108, 47, 98, 121, 116, 101, 115, 116, 114,
+            101, 97, 109, 115, 31, 104, 116, 116, 112, 58,47, 47, 106, 97, 98,
+            98, 101, 114, 46, 111, 114, 103, 47, 112, 114, 111, 116, 111, 99,
+            111, 108, 47, 99, 104, 97, 116, 115, 116, 97, 116, 101, 115, 31,
+            104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111,
+            114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 99, 111,
+            109, 109, 97, 110, 100, 115, 31,104,116, 116, 112, 58, 47, 47, 106,
+            97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114, 111, 116,
+            111, 99, 111, 108, 47, 100, 105, 115, 99, 111, 35, 105, 110, 102,
+            111, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114,
+            46, 111, 114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47,
+            100, 105, 115, 99, 111, 35, 105, 116, 101, 109, 115, 31, 104, 116,
+            116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103,
+            47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 101, 118, 105, 108,
+            31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46,
+            111, 114, 103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 102,
+            101, 97, 116, 117, 114, 101, 45, 110, 101, 103, 31, 104, 116, 116,
+            112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47,
+            112, 114, 111, 116, 111, 99, 111, 108, 47, 103, 101, 111, 108, 111,
+            99, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114,
+            46, 111, 114, 103, 47, 112, 114, 111, 116, 111, 99,111, 108, 47,
+            103, 101, 111, 108, 111, 99, 43, 110, 111, 116, 105, 102, 121, 31,
+            104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111,
+            114, 103,47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 105, 98,
+            98, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114,
+            46, 111, 114, 103, 47, 112, 114, 111,116, 111, 99, 111, 108, 47,
+            105, 113, 105, 98, 98, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97,
+            98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114, 111, 116,111,
+            99, 111, 108, 47, 109, 111, 111, 100, 31, 104, 116, 116, 112, 58,
+            47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114,
+            111, 116, 111, 99, 111,108, 47, 109, 111, 111, 100, 43, 110, 111,
+            116, 105, 102, 121, 31, 104, 116, 116, 112, 58, 47, 47, 106, 97,
+            98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114, 111, 116, 111,
+            99, 111, 108, 47, 114, 111, 115, 116, 101, 114, 120, 31, 104, 116,
+            116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103,
+            47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 115, 105, 31, 104,
+            116, 116, 112, 58, 47, 47, 106, 97, 98, 98, 101, 114, 46, 111, 114,
+            103, 47, 112, 114, 111, 116, 111, 99, 111, 108, 47, 115, 105, 47,
+            112, 114, 111, 102, 105, 108, 101, 47, 102, 105, 108, 101, 45, 116,
+            114, 97, 110, 115, 102, 101, 114, 31, 104, 116, 116, 112, 58, 47,
+            47, 106, 97, 98, 98, 101, 114, 46, 111, 114, 103, 47, 112, 114,
+            111, 116, 111, 99, 111, 108, 47, 116, 117, 110, 101, 31, 104, 116,
+            116, 112, 58, 47, 47, 119, 119, 119, 46, 102, 97, 99, 101, 98, 111,
+            111, 107, 46, 99, 111, 109, 47, 120, 109, 112, 112, 47, 109, 101,
+            115, 115, 97, 103, 101, 115, 31, 104, 116, 116, 112, 58, 47, 47,
+            119, 119, 119, 46, 120, 109, 112, 112, 46, 111, 114, 103, 47, 101,
+            120, 116, 101, 110, 115, 105, 111, 110, 115, 47, 120, 101, 112, 45,
+            48, 48, 56, 52, 46, 104, 116, 109, 108, 35, 110, 115, 45, 109, 101,
+            116, 97, 100, 97, 116, 97, 43, 110, 111, 116, 105, 102, 121, 31,
+            106, 97, 98, 98, 101, 114,58, 105,113, 58, 97, 118, 97, 116, 97,
+            114, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113, 58, 98, 114, 111,
+            119, 115, 101, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113, 58,
+            100, 116, 99, 112, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113, 58,
+            102, 105, 108, 101, 120, 102, 101, 114, 31, 106, 97, 98, 98, 101,
+            114, 58, 105, 113, 58, 105, 98, 98, 31, 106, 97, 98, 98, 101, 114,
+            58, 105, 113, 58, 105, 110, 98, 97, 110, 100, 31, 106, 97, 98, 98,
+            101, 114, 58, 105, 113, 58, 106, 105, 100, 108, 105, 110, 107, 31,
+            106, 97, 98, 98, 101, 114, 58, 105, 113, 58, 108, 97, 115, 116, 31,
+            106, 97, 98, 98, 101, 114, 58, 105, 113, 58, 111, 111, 98, 31, 106,
+            97,98, 98, 101, 114, 58, 105, 113, 58, 112, 114, 105, 118, 97, 99,
+            121, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113, 58, 114, 111,
+            115, 116, 101, 114,31, 106, 97, 98, 98, 101, 114, 58, 105, 113, 58,
+            116, 105, 109, 101, 31, 106, 97, 98, 98, 101, 114, 58, 105, 113,
+            58, 118, 101, 114, 115, 105, 111, 110, 31, 106, 97, 98, 98, 101,
+            114, 58, 120, 58, 100, 97, 116, 97, 31, 106, 97, 98, 98, 101, 114,
+            58, 120, 58, 101, 118, 101, 110, 116, 31, 106, 97, 98, 98, 101,
+            114, 58, 120, 58, 111, 111, 98, 31, 117, 114, 110, 58, 120, 109,
+            112, 112, 58, 97, 118, 97, 116, 97, 114, 58, 109, 101, 116, 97,
+            100, 97, 116, 97, 43, 110, 111, 116, 105, 102, 121,31, 117, 114,
+            110, 58, 120, 109, 112, 112, 58, 112, 105, 110, 103, 31, 117, 114,
+            110, 58, 120, 109, 112, 112, 58, 114, 101, 99, 101, 105, 112, 116,
+            115, 31, 117, 114, 110, 58, 120, 109, 112, 112, 58, 116, 105, 109,
+            101, 31, 28, 99, 108, 105, 101, 110, 116, 31, 112, 99, 31, 101,
+            110, 31, 84, 107, 97, 98, 98, 101, 114,31, 30, 99, 108, 105, 101,
+            110, 116, 31, 112, 99, 31, 114, 117, 31, 208, 162, 208, 186, 208,
+            176, 208, 177, 208, 177, 208, 181, 209, 128, 31, 30, 28, 70, 79,
+            82, 77, 95, 84, 89, 80, 69, 31, 117, 114, 110, 58, 120, 109, 112,
+            112, 58, 100, 97, 116, 97, 102, 111, 114, 109, 115, 58, 115, 111,
+            102, 116, 119, 97, 114, 101,105, 110, 102, 111, 31, 30, 111, 115,
+            31, 87, 105, 110, 100, 111, 119, 115, 31, 30, 111, 115, 95, 118,
+            101, 114, 115, 105, 111, 110, 31, 88, 80, 31, 30, 115, 111, 102,
+            116, 119, 97, 114, 101, 31, 84, 107, 97, 98, 98, 101, 114, 31, 30,
+            115, 111, 102, 116, 119, 97, 114, 101, 95, 118, 101, 114, 115, 105,
+            111, 110, 31, 48, 46, 49, 49, 46, 49, 45, 115, 118, 110, 45, 50,
+            48, 49, 49, 49, 50, 49, 54, 45, 109, 111, 100, 32, 40, 84, 99, 108,
+            47, 84, 107, 32, 56, 46,54, 98, 50, 41, 31, 30, 29, 28];
+        let ecaps2 = ecaps2::convert_element(&elem).unwrap();
+        assert_eq!(ecaps2.len(), 0x543);
+        assert_eq!(ecaps2, expected);
+
+        /*
+        let sha_256 = hash(ecaps2, "sha-256");
+        assert_eq!(sha_256, "u79ZroNJbdSWhdSp311mddz44oHHPsEBntQ5b1jqBSY=");
+        let sha3_256 = hash(ecaps2, "sha3-256");
+        assert_eq!(sha3_256, "XpUJzLAc93258sMECZ3FJpebkzuyNXDzRNwQog8eycg=");
+        */
+    }
+}
diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 00000000..bd7d2d9c
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,23 @@
+use std::convert::From;
+use std::io;
+
+use minidom;
+
+#[derive(Debug)]
+pub enum Error {
+    IoError(io::Error),
+    XMLError(minidom::Error),
+    ParseError(&'static str),
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Error {
+        Error::IoError(err)
+    }
+}
+
+impl From<minidom::Error> for Error {
+    fn from(err: minidom::Error) -> Error {
+        Error::XMLError(err)
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 00000000..a6aa1901
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,9 @@
+extern crate minidom;
+
+pub mod error;
+pub mod ns;
+
+pub mod disco;
+pub mod data_forms;
+pub mod media_element;
+pub mod ecaps2;
diff --git a/src/media_element.rs b/src/media_element.rs
new file mode 100644
index 00000000..1fc84507
--- /dev/null
+++ b/src/media_element.rs
@@ -0,0 +1,177 @@
+use minidom::Element;
+
+use error::Error;
+
+const MEDIA_ELEMENT_NS: &'static str = "urn:xmpp:media-element";
+
+#[derive(Debug)]
+pub struct URI {
+    pub type_: String,
+    pub uri: String,
+}
+
+#[derive(Debug)]
+pub struct MediaElement {
+    pub width: Option<usize>,
+    pub height: Option<usize>,
+    pub uris: Vec<URI>,
+}
+
+pub fn parse_media_element(root: &Element) -> Result<MediaElement, Error> {
+    assert!(root.is("media", MEDIA_ELEMENT_NS));
+    let width = root.attr("width").and_then(|width| width.parse().ok());
+    let height = root.attr("height").and_then(|height| height.parse().ok());
+    let mut uris = vec!();
+    for uri in root.children() {
+        if uri.is("uri", MEDIA_ELEMENT_NS) {
+            let type_ = uri.attr("type").ok_or(Error::ParseError("Attribute type on uri is mandatory."))?;
+            let text = uri.text().trim().to_owned();
+            if text == "" {
+                return Err(Error::ParseError("URI missing in uri."));
+            }
+            uris.push(URI { type_: type_.to_owned(), uri: text });
+        } else {
+            return Err(Error::ParseError("Unknown child in media element."));
+        }
+    }
+    Ok(MediaElement { width: width, height: height, uris: uris })
+}
+
+#[cfg(test)]
+mod tests {
+    use minidom::Element;
+    use error::Error;
+    use media_element;
+    use data_forms;
+
+    #[test]
+    fn test_simple() {
+        let elem: Element = "<media xmlns='urn:xmpp:media-element'/>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert!(media.width.is_none());
+        assert!(media.height.is_none());
+        assert!(media.uris.is_empty());
+    }
+
+    #[test]
+    fn test_width_height() {
+        let elem: Element = "<media xmlns='urn:xmpp:media-element' width='32' height='32'/>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert_eq!(media.width.unwrap(), 32);
+        assert_eq!(media.height.unwrap(), 32);
+    }
+
+    #[test]
+    fn test_uri() {
+        let elem: Element = "<media xmlns='urn:xmpp:media-element'><uri type='text/html'>https://example.org/</uri></media>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert_eq!(media.uris.len(), 1);
+        assert_eq!(media.uris[0].type_, "text/html");
+        assert_eq!(media.uris[0].uri, "https://example.org/");
+    }
+
+    #[test]
+    fn test_invalid_width_height() {
+        let elem: Element = "<media xmlns='urn:xmpp:media-element' width=''/>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert!(media.width.is_none());
+
+        let elem: Element = "<media xmlns='urn:xmpp:media-element' width='coucou'/>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert!(media.width.is_none());
+
+        let elem: Element = "<media xmlns='urn:xmpp:media-element' height=''/>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert!(media.height.is_none());
+
+        let elem: Element = "<media xmlns='urn:xmpp:media-element' height='-10'/>".parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert!(media.height.is_none());
+    }
+
+    #[test]
+    fn test_unknown_child() {
+        let elem: Element = "<media xmlns='urn:xmpp:media-element'><coucou/></media>".parse().unwrap();
+        let error = media_element::parse_media_element(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Unknown child in media element.");
+    }
+
+    #[test]
+    fn test_bad_uri() {
+        let elem: Element = "<media xmlns='urn:xmpp:media-element'><uri>https://example.org/</uri></media>".parse().unwrap();
+        let error = media_element::parse_media_element(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Attribute type on uri is mandatory.");
+
+        let elem: Element = "<media xmlns='urn:xmpp:media-element'><uri type='text/html'/></media>".parse().unwrap();
+        let error = media_element::parse_media_element(&elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "URI missing in uri.");
+    }
+
+    #[test]
+    fn test_xep_ex1() {
+        let elem: Element = r#"
+<media xmlns='urn:xmpp:media-element'>
+  <uri type='audio/x-wav'>
+    http://victim.example.com/challenges/speech.wav?F3A6292C
+  </uri>
+  <uri type='audio/ogg; codecs=speex'>
+    cid:sha1+a15a505e360702b79c75a5f67773072ed392f52a@bob.xmpp.org
+  </uri>
+  <uri type='audio/mpeg'>
+    http://victim.example.com/challenges/speech.mp3?F3A6292C
+  </uri>
+</media>"#.parse().unwrap();
+        let media = media_element::parse_media_element(&elem).unwrap();
+        assert!(media.width.is_none());
+        assert!(media.height.is_none());
+        assert_eq!(media.uris.len(), 3);
+        assert_eq!(media.uris[0].type_, "audio/x-wav");
+        assert_eq!(media.uris[0].uri, "http://victim.example.com/challenges/speech.wav?F3A6292C");
+        assert_eq!(media.uris[1].type_, "audio/ogg; codecs=speex");
+        assert_eq!(media.uris[1].uri, "cid:sha1+a15a505e360702b79c75a5f67773072ed392f52a@bob.xmpp.org");
+        assert_eq!(media.uris[2].type_, "audio/mpeg");
+        assert_eq!(media.uris[2].uri, "http://victim.example.com/challenges/speech.mp3?F3A6292C");
+    }
+
+    #[test]
+    fn test_xep_ex2() {
+        let elem: Element = r#"
+<x xmlns='jabber:x:data' type='form'>
+  [ ... ]
+  <field var='ocr'>
+    <media xmlns='urn:xmpp:media-element'
+           height='80'
+           width='290'>
+      <uri type='image/jpeg'>
+        http://www.victim.com/challenges/ocr.jpeg?F3A6292C
+      </uri>
+      <uri type='image/jpeg'>
+        cid:sha1+f24030b8d91d233bac14777be5ab531ca3b9f102@bob.xmpp.org
+      </uri>
+    </media>
+  </field>
+  [ ... ]
+</x>"#.parse().unwrap();
+        let form = data_forms::parse_data_form(&elem).unwrap();
+        assert_eq!(form.fields.len(), 1);
+        assert_eq!(form.fields[0].var, "ocr");
+        assert_eq!(form.fields[0].media[0].width, Some(290));
+        assert_eq!(form.fields[0].media[0].height, Some(80));
+        assert_eq!(form.fields[0].media[0].uris[0].type_, "image/jpeg");
+        assert_eq!(form.fields[0].media[0].uris[0].uri, "http://www.victim.com/challenges/ocr.jpeg?F3A6292C");
+        assert_eq!(form.fields[0].media[0].uris[1].type_, "image/jpeg");
+        assert_eq!(form.fields[0].media[0].uris[1].uri, "cid:sha1+f24030b8d91d233bac14777be5ab531ca3b9f102@bob.xmpp.org");
+    }
+}
diff --git a/src/ns.rs b/src/ns.rs
new file mode 100644
index 00000000..36bd127c
--- /dev/null
+++ b/src/ns.rs
@@ -0,0 +1,3 @@
+pub const DISCO_INFO_NS: &'static str = "http://jabber.org/protocol/disco#info";
+pub const DATA_FORMS_NS: &'static str = "jabber:x:data";
+pub const MEDIA_ELEMENT_NS: &'static str = "urn:xmpp:media-element";