Web Crypto API
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The Web Crypto API is an interface allowing a script to use cryptographic primitives in order to build systems using cryptography.
Some browsers implemented an interface called Crypto without having it well defined or being cryptographically sound.
In order to avoid confusion, methods and properties of this interface have been removed from browsers implementing the Web Crypto API, and all Web Crypto API methods are available on a new interface: SubtleCrypto.
The Crypto.subtle property gives access to an object implementing it.
Warning: The Web Crypto API provides a number of low-level cryptographic primitives. It's very easy to misuse them, and the pitfalls involved can be very subtle.
Even assuming you use the basic cryptographic functions correctly, secure key management and overall security system design are extremely hard to get right, and are generally the domain of specialist security experts.
Errors in security system design and implementation can make the security of the system completely ineffective.
Please learn and experiment, but don't guarantee or imply the security of your work before an individual knowledgeable in this subject matter thoroughly reviews it. The Crypto 101 Course can be a great place to start learning about the design and implementation of secure systems.
Interfaces
Crypto-
Provides basic cryptography features, such as a cryptographically strong random number generator, and access to cryptographic primitives via a
SubtleCryptoobject. An object of this type can be accessed in the global scope usingWindow.cryptoorWorkerGlobalScope.crypto. SubtleCrypto-
Represents an object that provides low-level cryptographic functions for key generation, encryption, decryption, key wrapping and unwrapping, and so on.
CryptoKey-
Represents a cryptographic key obtained from one of the
SubtleCryptomethodsgenerateKey(),deriveKey(),importKey(), orunwrapKey().
Dictionaries
AesCbcParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.encrypt(),SubtleCrypto.decrypt(),SubtleCrypto.wrapKey(), orSubtleCrypto.unwrapKey(), when using the AES-CBC algorithm. AesCtrParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.encrypt(),SubtleCrypto.decrypt(),SubtleCrypto.wrapKey(), orSubtleCrypto.unwrapKey(), when using the AES-CTR algorithm. AesGcmParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.encrypt(),SubtleCrypto.decrypt(),SubtleCrypto.wrapKey(), orSubtleCrypto.unwrapKey(), when using the AES-GCM algorithm. AesKeyGenParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.generateKey(), when generating an AES key: that is, when the algorithm is identified as any of AES-CBC, AES-CTR, AES-GCM, or AES-KW. CryptoKeyPair-
Represents a public and private key pair used for an asymmetric cryptography algorithm.
EcKeyGenParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.generateKey(), when generating any elliptic-curve-based key pair: that is, when the algorithm is identified as either of ECDSA or ECDH. EcKeyImportParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.importKey()orSubtleCrypto.unwrapKey(), when generating any elliptic-curve-based key pair: that is, when the algorithm is identified as either of ECDSA or ECDH. EcdhKeyDeriveParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.deriveKey(), when using the ECDH algorithm. EcdsaParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.sign()orSubtleCrypto.verify()when using the ECDSA algorithm. HkdfParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.deriveKey(), when using the HKDF algorithm. HmacImportParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.importKey()orSubtleCrypto.unwrapKey(), when generating a key for the HMAC algorithm. HmacKeyGenParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.generateKey(), when generating a key for the HMAC algorithm. Pbkdf2Params-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.deriveKey(), when using the PBKDF2 algorithm. RsaHashedImportParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.importKey()orSubtleCrypto.unwrapKey(), when importing any RSA-based key pair: that is, when the algorithm is identified as any of RSASSA-PKCS1-v1_5, RSA-PSS, or RSA-OAEP. RsaHashedKeyGenParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.generateKey(), when generating any RSA-based key pair: that is, when the algorithm is identified as any of RSASSA-PKCS1-v1_5, RSA-PSS, or RSA-OAEP. RsaOaepParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.encrypt(),SubtleCrypto.decrypt(),SubtleCrypto.wrapKey(), orSubtleCrypto.unwrapKey(), when using the RSA_OAEP algorithm. RsaPssParams-
Represents the object that should be passed as the
algorithmparameter intoSubtleCrypto.sign()orSubtleCrypto.verify(), when using the RSA-PSS algorithm.
Extensions to other interfaces
Window.crypto-
Represents the
Cryptoobject associated with the global object in the main thread scope. WorkerGlobalScope.crypto-
Represents
Cryptoobject associated with the global object in worker scope.
Specifications
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| Web Cryptography Level 2 # crypto-interface |
Browser compatibility
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Crypto
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getRandomValues()
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randomUUID()
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subtle
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Secure context required
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Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- Partial support
- Partial support
- No support
- No support
- See implementation notes.
- Requires a vendor prefix or different name for use.
- Has more compatibility info.