# RSAPublicKeySpec

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)

# RSAPublicKeySpec

```
open class RSAPublicKeySpec : KeySpec
```

|---|----------------------------------------------------------------------------------------------------------------------------|
| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)                                             ||
| ↳ | [java.security.spec.RSAPublicKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAPublicKeySpec#) |

This class specifies an RSA public key.

## Summary

|                                                                                                                                                                                                                                                                                                             Public constructors                                                                                                                                                                                                                                                                                                              ||
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| [RSAPublicKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAPublicKeySpec#RSAPublicKeySpec(java.math.BigInteger,%20java.math.BigInteger))`(`modulus:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `publicExponent:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`)` Creates a new RSAPublicKeySpec.                                                                                                                                                                                                              |
| [RSAPublicKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAPublicKeySpec#RSAPublicKeySpec(java.math.BigInteger,%20java.math.BigInteger,%20java.security.spec.AlgorithmParameterSpec))`(`modulus:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `publicExponent:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `params:` `[AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)!`)` Creates a new RSAPublicKeySpec with additional key parameters. |

|                                                                                                                                                    Public methods                                                                                                                                                     ||
|-------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!                            | [getModulus](https://developer.android.com/reference/kotlin/java/security/spec/RSAPublicKeySpec#getModulus())`()` Returns the modulus.                                                       |
| open[AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)! | [getParams](https://developer.android.com/reference/kotlin/java/security/spec/RSAPublicKeySpec#getParams())`()` Returns the parameters associated with this key, may be null if not present. |
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!                            | [getPublicExponent](https://developer.android.com/reference/kotlin/java/security/spec/RSAPublicKeySpec#getPublicExponent())`()` Returns the public exponent.                                 |

## Public constructors

### RSAPublicKeySpec

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
RSAPublicKeySpec(
    modulus: BigInteger!, 
    publicExponent: BigInteger!)
```

Creates a new RSAPublicKeySpec.

|                                                           Parameters                                                           ||
|------------------|--------------------------------------------------------------------------------------------------------------|
| `modulus`        | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the modulus         |
| `publicExponent` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the public exponent |

### RSAPublicKeySpec

Added in[API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
RSAPublicKeySpec(
    modulus: BigInteger!, 
    publicExponent: BigInteger!, 
    params: AlgorithmParameterSpec!)
```

Creates a new RSAPublicKeySpec with additional key parameters.

|                                                                                         Parameters                                                                                         ||
|------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `modulus`        | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the modulus                                                                     |
| `publicExponent` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the public exponent                                                             |
| `params`         | [AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)!:the parameters associated with this key, may be null |

## Public methods

### getModulus

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
open fun getModulus(): BigInteger!
```

Returns the modulus.

|                                                Return                                                 ||
|------------------------------------------------------------------------------------------|-------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the modulus |

### getParams

Added in[API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
open fun getParams(): AlgorithmParameterSpec!
```

Returns the parameters associated with this key, may be null if not present.

|                                                                            Return                                                                            ||
|---------------------------------------------------------------------------------------------------------------------|-----------------------------------------|
| [AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)! | the parameters associated with this key |

### getPublicExponent

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
open fun getPublicExponent(): BigInteger!
```

Returns the public exponent.

|                                                    Return                                                     ||
|------------------------------------------------------------------------------------------|---------------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the public exponent |