- java.lang.Object
-
- java.security.KeyStore
-
public class KeyStore extends Object
This class represents a storage facility for cryptographic keys and certificates.A
KeyStore
manages different types of entries. Each type of entry implements theKeyStore.Entry
interface. Three basicKeyStore.Entry
implementations are provided:- KeyStore.PrivateKeyEntry
This type of entry holds a cryptographic
PrivateKey
, which is optionally stored in a protected format to prevent unauthorized access. It is also accompanied by a certificate chain for the corresponding public key.Private keys and certificate chains are used by a given entity for self-authentication. Applications for this authentication include software distribution organizations which sign JAR files as part of releasing and/or licensing software.
- KeyStore.SecretKeyEntry
This type of entry holds a cryptographic
SecretKey
, which is optionally stored in a protected format to prevent unauthorized access. - KeyStore.TrustedCertificateEntry
This type of entry contains a single public key
Certificate
belonging to another party. It is called a trusted certificate because the keystore owner trusts that the public key in the certificate indeed belongs to the identity identified by the subject (owner) of the certificate.This type of entry can be used to authenticate other parties.
Each entry in a keystore is identified by an "alias" string. In the case of private keys and their associated certificate chains, these strings distinguish among the different ways in which the entity may authenticate itself. For example, the entity may authenticate itself using different certificate authorities, or using different public key algorithms.
Whether aliases are case sensitive is implementation dependent. In order to avoid problems, it is recommended not to use aliases in a KeyStore that only differ in case.
Whether keystores are persistent, and the mechanisms used by the keystore if it is persistent, are not specified here. This allows use of a variety of techniques for protecting sensitive (e.g., private or secret) keys. Smart cards or other integrated cryptographic engines (SafeKeyper) are one option, and simpler mechanisms such as files may also be used (in a variety of formats).
Typical ways to request a KeyStore object include relying on the default type and providing a specific keystore type.
- To rely on the default type:
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
The system will return a keystore implementation for the default type. - To provide a specific keystore type:
KeyStore ks = KeyStore.getInstance("JKS");
The system will return the most preferred implementation of the specified keystore type available in the environment.
Before a keystore can be accessed, it must be
loaded
.KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType()); // get user password and file input stream char[] password = getPassword(); java.io.FileInputStream fis = null; try { fis = new java.io.FileInputStream("keyStoreName"); ks.load(fis, password); } finally { if (fis != null) { fis.close(); } }
To create an empty keystore using the aboveload
method, passnull
as theInputStream
argument.Once the keystore has been loaded, it is possible to read existing entries from the keystore, or to write new entries into the keystore:
KeyStore.ProtectionParameter protParam = new KeyStore.PasswordProtection(password); // get my private key KeyStore.PrivateKeyEntry pkEntry = (KeyStore.PrivateKeyEntry) ks.getEntry("privateKeyAlias", protParam); PrivateKey myPrivateKey = pkEntry.getPrivateKey(); // save my secret key javax.crypto.SecretKey mySecretKey; KeyStore.SecretKeyEntry skEntry = new KeyStore.SecretKeyEntry(mySecretKey); ks.setEntry("secretKeyAlias", skEntry, protParam); // store away the keystore java.io.FileOutputStream fos = null; try { fos = new java.io.FileOutputStream("newKeyStoreName"); ks.store(fos, password); } finally { if (fos != null) { fos.close(); } }
Note that although the same password may be used to load the keystore, to protect the private key entry, to protect the secret key entry, and to store the keystore (as is shown in the sample code above), different passwords or other protection parameters may also be used.Every implementation of the Java platform is required to support the following standard
KeyStore
type:- PKCS12
- Since:
- 1.2
- See Also:
PrivateKey
,SecretKey
,Certificate
- KeyStore.PrivateKeyEntry
-
-
Nested Class Summary
Nested Classes Modifier and Type Class and Description static class
KeyStore.Builder
A description of a to-be-instantiated KeyStore object.static class
KeyStore.CallbackHandlerProtection
A ProtectionParameter encapsulating a CallbackHandler.static interface
KeyStore.Entry
A marker interface forKeyStore
entry types.static interface
KeyStore.LoadStoreParameter
static class
KeyStore.PasswordProtection
A password-based implementation ofProtectionParameter
.static class
KeyStore.PrivateKeyEntry
AKeyStore
entry that holds aPrivateKey
and corresponding certificate chain.static interface
KeyStore.ProtectionParameter
A marker interface for keystore protection parameters.static class
KeyStore.SecretKeyEntry
AKeyStore
entry that holds aSecretKey
.static class
KeyStore.TrustedCertificateEntry
AKeyStore
entry that holds a trustedCertificate
.
-
Constructor Summary
Constructors Modifier Constructor and Description protected
KeyStore(KeyStoreSpi keyStoreSpi, Provider provider, String type)
Creates a KeyStore object of the given type, and encapsulates the given provider implementation (SPI object) in it.
-
Method Summary
Methods Modifier and Type Method and Description Enumeration<String>
aliases()
Lists all the alias names of this keystore.boolean
containsAlias(String alias)
Checks if the given alias exists in this keystore.void
deleteEntry(String alias)
Deletes the entry identified by the given alias from this keystore.boolean
entryInstanceOf(String alias, Class<? extends KeyStore.Entry> entryClass)
Determines if the keystoreEntry
for the specifiedalias
is an instance or subclass of the specifiedentryClass
.Certificate
getCertificate(String alias)
Returns the certificate associated with the given alias.String
getCertificateAlias(Certificate cert)
Returns the (alias) name of the first keystore entry whose certificate matches the given certificate.Certificate[]
getCertificateChain(String alias)
Returns the certificate chain associated with the given alias.Date
getCreationDate(String alias)
Returns the creation date of the entry identified by the given alias.static String
getDefaultType()
Returns the default keystore type as specified in the Java security properties file, or the string "jks" (acronym for "Java keystore") if no such property exists.KeyStore.Entry
getEntry(String alias, KeyStore.ProtectionParameter protParam)
Gets a keystoreEntry
for the specified alias with the specified protection parameter.static KeyStore
getInstance(String type)
Returns a keystore object of the specified type.static KeyStore
getInstance(String type, Provider provider)
Returns a keystore object of the specified type.static KeyStore
getInstance(String type, String provider)
Returns a keystore object of the specified type.Key
getKey(String alias, char[] password)
Returns the key associated with the given alias, using the given password to recover it.Provider
getProvider()
Returns the provider of this keystore.String
getType()
Returns the type of this keystore.boolean
isCertificateEntry(String alias)
Returns true if the entry identified by the given alias was created by a call tosetCertificateEntry
, or created by a call tosetEntry
with aTrustedCertificateEntry
.boolean
isKeyEntry(String alias)
Returns true if the entry identified by the given alias was created by a call tosetKeyEntry
, or created by a call tosetEntry
with aPrivateKeyEntry
or aSecretKeyEntry
.void
load(InputStream stream, char[] password)
Loads this KeyStore from the given input stream.void
load(KeyStore.LoadStoreParameter param)
Loads this keystore using the givenLoadStoreParameter
.void
setCertificateEntry(String alias, Certificate cert)
Assigns the given trusted certificate to the given alias.void
setEntry(String alias, KeyStore.Entry entry, KeyStore.ProtectionParameter protParam)
Saves a keystoreEntry
under the specified alias.void
setKeyEntry(String alias, byte[] key, Certificate[] chain)
Assigns the given key (that has already been protected) to the given alias.void
setKeyEntry(String alias, Key key, char[] password, Certificate[] chain)
Assigns the given key to the given alias, protecting it with the given password.int
size()
Retrieves the number of entries in this keystore.void
store(KeyStore.LoadStoreParameter param)
Stores this keystore using the givenLoadStoreParameter
.void
store(OutputStream stream, char[] password)
Stores this keystore to the given output stream, and protects its integrity with the given password.
-
-
-
Constructor Detail
-
KeyStore
protected KeyStore(KeyStoreSpi keyStoreSpi, Provider provider, String type)
Creates a KeyStore object of the given type, and encapsulates the given provider implementation (SPI object) in it.- Parameters:
keyStoreSpi
- the provider implementation.provider
- the provider.type
- the keystore type.
-
-
Method Detail
-
getInstance
public static KeyStore getInstance(String type) throws KeyStoreException
Returns a keystore object of the specified type.This method traverses the list of registered security Providers, starting with the most preferred Provider. A new KeyStore object encapsulating the KeyStoreSpi implementation from the first Provider that supports the specified type is returned.
Note that the list of registered providers may be retrieved via the
Security.getProviders()
method.- Parameters:
type
- the type of keystore. See the KeyStore section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard keystore types.- Returns:
- a keystore object of the specified type.
- Throws:
KeyStoreException
- if no Provider supports a KeyStoreSpi implementation for the specified type.- See Also:
Provider
-
getInstance
public static KeyStore getInstance(String type, String provider) throws KeyStoreException, NoSuchProviderException
Returns a keystore object of the specified type.A new KeyStore object encapsulating the KeyStoreSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.
Note that the list of registered providers may be retrieved via the
Security.getProviders()
method.- Parameters:
type
- the type of keystore. See the KeyStore section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard keystore types.provider
- the name of the provider.- Returns:
- a keystore object of the specified type.
- Throws:
KeyStoreException
- if a KeyStoreSpi implementation for the specified type is not available from the specified provider.NoSuchProviderException
- if the specified provider is not registered in the security provider list.IllegalArgumentException
- if the provider name is null or empty.- See Also:
Provider
-
getInstance
public static KeyStore getInstance(String type, Provider provider) throws KeyStoreException
Returns a keystore object of the specified type.A new KeyStore object encapsulating the KeyStoreSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.
- Parameters:
type
- the type of keystore. See the KeyStore section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard keystore types.provider
- the provider.- Returns:
- a keystore object of the specified type.
- Throws:
KeyStoreException
- if KeyStoreSpi implementation for the specified type is not available from the specified Provider object.IllegalArgumentException
- if the specified provider is null.- Since:
- 1.4
- See Also:
Provider
-
getDefaultType
public static final String getDefaultType()
Returns the default keystore type as specified in the Java security properties file, or the string "jks" (acronym for "Java keystore") if no such property exists. The Java security properties file is located in the file named <JAVA_HOME>/lib/security/java.security. <JAVA_HOME> refers to the value of the java.home system property, and specifies the directory where the JRE is installed.The default keystore type can be used by applications that do not want to use a hard-coded keystore type when calling one of the
getInstance
methods, and want to provide a default keystore type in case a user does not specify its own.The default keystore type can be changed by setting the value of the "keystore.type" security property (in the Java security properties file) to the desired keystore type.
- Returns:
- the default keystore type as specified in the Java security properties file, or the string "jks" if no such property exists.
-
getProvider
public final Provider getProvider()
Returns the provider of this keystore.- Returns:
- the provider of this keystore.
-
getType
public final String getType()
Returns the type of this keystore.- Returns:
- the type of this keystore.
-
getKey
public final Key getKey(String alias, char[] password) throws KeyStoreException, NoSuchAlgorithmException, UnrecoverableKeyException
Returns the key associated with the given alias, using the given password to recover it. The key must have been associated with the alias by a call tosetKeyEntry
, or by a call tosetEntry
with aPrivateKeyEntry
orSecretKeyEntry
.- Parameters:
alias
- the alias namepassword
- the password for recovering the key- Returns:
- the requested key, or null if the given alias does not exist or does not identify a key-related entry.
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).NoSuchAlgorithmException
- if the algorithm for recovering the key cannot be foundUnrecoverableKeyException
- if the key cannot be recovered (e.g., the given password is wrong).
-
getCertificateChain
public final Certificate[] getCertificateChain(String alias) throws KeyStoreException
Returns the certificate chain associated with the given alias. The certificate chain must have been associated with the alias by a call tosetKeyEntry
, or by a call tosetEntry
with aPrivateKeyEntry
.- Parameters:
alias
- the alias name- Returns:
- the certificate chain (ordered with the user's certificate first followed by zero or more certificate authorities), or null if the given alias does not exist or does not contain a certificate chain
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
getCertificate
public final Certificate getCertificate(String alias) throws KeyStoreException
Returns the certificate associated with the given alias.If the given alias name identifies an entry created by a call to
setCertificateEntry
, or created by a call tosetEntry
with aTrustedCertificateEntry
, then the trusted certificate contained in that entry is returned.If the given alias name identifies an entry created by a call to
setKeyEntry
, or created by a call tosetEntry
with aPrivateKeyEntry
, then the first element of the certificate chain in that entry is returned.- Parameters:
alias
- the alias name- Returns:
- the certificate, or null if the given alias does not exist or does not contain a certificate.
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
getCreationDate
public final Date getCreationDate(String alias) throws KeyStoreException
Returns the creation date of the entry identified by the given alias.- Parameters:
alias
- the alias name- Returns:
- the creation date of this entry, or null if the given alias does not exist
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
setKeyEntry
public final void setKeyEntry(String alias, Key key, char[] password, Certificate[] chain) throws KeyStoreException
Assigns the given key to the given alias, protecting it with the given password.If the given key is of type
java.security.PrivateKey
, it must be accompanied by a certificate chain certifying the corresponding public key.If the given alias already exists, the keystore information associated with it is overridden by the given key (and possibly certificate chain).
- Parameters:
alias
- the alias namekey
- the key to be associated with the aliaspassword
- the password to protect the keychain
- the certificate chain for the corresponding public key (only required if the given key is of typejava.security.PrivateKey
).- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded), the given key cannot be protected, or this operation fails for some other reason
-
setKeyEntry
public final void setKeyEntry(String alias, byte[] key, Certificate[] chain) throws KeyStoreException
Assigns the given key (that has already been protected) to the given alias.If the protected key is of type
java.security.PrivateKey
, it must be accompanied by a certificate chain certifying the corresponding public key. If the underlying keystore implementation is of typejks
,key
must be encoded as anEncryptedPrivateKeyInfo
as defined in the PKCS #8 standard.If the given alias already exists, the keystore information associated with it is overridden by the given key (and possibly certificate chain).
- Parameters:
alias
- the alias namekey
- the key (in protected format) to be associated with the aliaschain
- the certificate chain for the corresponding public key (only useful if the protected key is of typejava.security.PrivateKey
).- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded), or if this operation fails for some other reason.
-
setCertificateEntry
public final void setCertificateEntry(String alias, Certificate cert) throws KeyStoreException
Assigns the given trusted certificate to the given alias.If the given alias identifies an existing entry created by a call to
setCertificateEntry
, or created by a call tosetEntry
with aTrustedCertificateEntry
, the trusted certificate in the existing entry is overridden by the given certificate.- Parameters:
alias
- the alias namecert
- the certificate- Throws:
KeyStoreException
- if the keystore has not been initialized, or the given alias already exists and does not identify an entry containing a trusted certificate, or this operation fails for some other reason.
-
deleteEntry
public final void deleteEntry(String alias) throws KeyStoreException
Deletes the entry identified by the given alias from this keystore.- Parameters:
alias
- the alias name- Throws:
KeyStoreException
- if the keystore has not been initialized, or if the entry cannot be removed.
-
aliases
public final Enumeration<String> aliases() throws KeyStoreException
Lists all the alias names of this keystore.- Returns:
- enumeration of the alias names
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
containsAlias
public final boolean containsAlias(String alias) throws KeyStoreException
Checks if the given alias exists in this keystore.- Parameters:
alias
- the alias name- Returns:
- true if the alias exists, false otherwise
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
size
public final int size() throws KeyStoreException
Retrieves the number of entries in this keystore.- Returns:
- the number of entries in this keystore
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
isKeyEntry
public final boolean isKeyEntry(String alias) throws KeyStoreException
Returns true if the entry identified by the given alias was created by a call tosetKeyEntry
, or created by a call tosetEntry
with aPrivateKeyEntry
or aSecretKeyEntry
.- Parameters:
alias
- the alias for the keystore entry to be checked- Returns:
- true if the entry identified by the given alias is a key-related entry, false otherwise.
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
isCertificateEntry
public final boolean isCertificateEntry(String alias) throws KeyStoreException
Returns true if the entry identified by the given alias was created by a call tosetCertificateEntry
, or created by a call tosetEntry
with aTrustedCertificateEntry
.- Parameters:
alias
- the alias for the keystore entry to be checked- Returns:
- true if the entry identified by the given alias contains a trusted certificate, false otherwise.
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
getCertificateAlias
public final String getCertificateAlias(Certificate cert) throws KeyStoreException
Returns the (alias) name of the first keystore entry whose certificate matches the given certificate.This method attempts to match the given certificate with each keystore entry. If the entry being considered was created by a call to
setCertificateEntry
, or created by a call tosetEntry
with aTrustedCertificateEntry
, then the given certificate is compared to that entry's certificate.If the entry being considered was created by a call to
setKeyEntry
, or created by a call tosetEntry
with aPrivateKeyEntry
, then the given certificate is compared to the first element of that entry's certificate chain.- Parameters:
cert
- the certificate to match with.- Returns:
- the alias name of the first entry with a matching certificate, or null if no such entry exists in this keystore.
- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).
-
store
public final void store(OutputStream stream, char[] password) throws KeyStoreException, IOException, NoSuchAlgorithmException, CertificateException
Stores this keystore to the given output stream, and protects its integrity with the given password.- Parameters:
stream
- the output stream to which this keystore is written.password
- the password to generate the keystore integrity check- Throws:
KeyStoreException
- if the keystore has not been initialized (loaded).IOException
- if there was an I/O problem with dataNoSuchAlgorithmException
- if the appropriate data integrity algorithm could not be foundCertificateException
- if any of the certificates included in the keystore data could not be stored
-
store
public final void store(KeyStore.LoadStoreParameter param) throws KeyStoreException, IOException, NoSuchAlgorithmException, CertificateException
Stores this keystore using the givenLoadStoreParameter
.- Parameters:
param
- theLoadStoreParameter
that specifies how to store the keystore, which may benull
- Throws:
IllegalArgumentException
- if the givenLoadStoreParameter
input is not recognizedKeyStoreException
- if the keystore has not been initialized (loaded)IOException
- if there was an I/O problem with dataNoSuchAlgorithmException
- if the appropriate data integrity algorithm could not be foundCertificateException
- if any of the certificates included in the keystore data could not be stored- Since:
- 1.5
-
load
public final void load(InputStream stream, char[] password) throws IOException, NoSuchAlgorithmException, CertificateException
Loads this KeyStore from the given input stream.A password may be given to unlock the keystore (e.g. the keystore resides on a hardware token device), or to check the integrity of the keystore data. If a password is not given for integrity checking, then integrity checking is not performed.
In order to create an empty keystore, or if the keystore cannot be initialized from a stream, pass
null
as thestream
argument.Note that if this keystore has already been loaded, it is reinitialized and loaded again from the given input stream.
- Parameters:
stream
- the input stream from which the keystore is loaded, ornull
password
- the password used to check the integrity of the keystore, the password used to unlock the keystore, ornull
- Throws:
IOException
- if there is an I/O or format problem with the keystore data, if a password is required but not given, or if the given password was incorrect. If the error is due to a wrong password, thecause
of theIOException
should be anUnrecoverableKeyException
NoSuchAlgorithmException
- if the algorithm used to check the integrity of the keystore cannot be foundCertificateException
- if any of the certificates in the keystore could not be loaded
-
load
public final void load(KeyStore.LoadStoreParameter param) throws IOException, NoSuchAlgorithmException, CertificateException
Loads this keystore using the givenLoadStoreParameter
.Note that if this KeyStore has already been loaded, it is reinitialized and loaded again from the given parameter.
- Parameters:
param
- theLoadStoreParameter
that specifies how to load the keystore, which may benull
- Throws:
IllegalArgumentException
- if the givenLoadStoreParameter
input is not recognizedIOException
- if there is an I/O or format problem with the keystore data. If the error is due to an incorrectProtectionParameter
(e.g. wrong password) thecause
of theIOException
should be anUnrecoverableKeyException
NoSuchAlgorithmException
- if the algorithm used to check the integrity of the keystore cannot be foundCertificateException
- if any of the certificates in the keystore could not be loaded- Since:
- 1.5
-
getEntry
public final KeyStore.Entry getEntry(String alias, KeyStore.ProtectionParameter protParam) throws NoSuchAlgorithmException, UnrecoverableEntryException, KeyStoreException
Gets a keystoreEntry
for the specified alias with the specified protection parameter.- Parameters:
alias
- get the keystoreEntry
for this aliasprotParam
- theProtectionParameter
used to protect theEntry
, which may benull
- Returns:
- the keystore
Entry
for the specified alias, ornull
if there is no such entry - Throws:
NullPointerException
- ifalias
isnull
NoSuchAlgorithmException
- if the algorithm for recovering the entry cannot be foundUnrecoverableEntryException
- if the specifiedprotParam
were insufficient or invalidUnrecoverableKeyException
- if the entry is aPrivateKeyEntry
orSecretKeyEntry
and the specifiedprotParam
does not contain the information needed to recover the key (e.g. wrong password)KeyStoreException
- if the keystore has not been initialized (loaded).- Since:
- 1.5
- See Also:
setEntry(String, KeyStore.Entry, KeyStore.ProtectionParameter)
-
setEntry
public final void setEntry(String alias, KeyStore.Entry entry, KeyStore.ProtectionParameter protParam) throws KeyStoreException
Saves a keystoreEntry
under the specified alias. The protection parameter is used to protect theEntry
.If an entry already exists for the specified alias, it is overridden.
- Parameters:
alias
- save the keystoreEntry
under this aliasentry
- theEntry
to saveprotParam
- theProtectionParameter
used to protect theEntry
, which may benull
- Throws:
NullPointerException
- ifalias
orentry
isnull
KeyStoreException
- if the keystore has not been initialized (loaded), or if this operation fails for some other reason- Since:
- 1.5
- See Also:
getEntry(String, KeyStore.ProtectionParameter)
-
entryInstanceOf
public final boolean entryInstanceOf(String alias, Class<? extends KeyStore.Entry> entryClass) throws KeyStoreException
Determines if the keystoreEntry
for the specifiedalias
is an instance or subclass of the specifiedentryClass
.- Parameters:
alias
- the alias nameentryClass
- the entry class- Returns:
- true if the keystore
Entry
for the specifiedalias
is an instance or subclass of the specifiedentryClass
, false otherwise - Throws:
NullPointerException
- ifalias
orentryClass
isnull
KeyStoreException
- if the keystore has not been initialized (loaded)- Since:
- 1.5
-
-
Traduction non disponible
Les API Java ne sont pas encore traduites en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.
Version en cache
22/12/2024 15:00:47 Cette version de la page est en cache (à la date du 22/12/2024 15:00:47) afin d'accélérer le traitement. Vous pouvez activer le mode utilisateur dans le menu en haut pour afficher la dernère version de la page.Document créé le 16/09/2006, dernière modification le 04/03/2020
Source du document imprimé : https://www.gaudry.be/java-api-rf-java/security/keystore.html
L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.
Références
Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.