# RSAMultiPrimePrivateCrtKeySpec
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
# RSAMultiPrimePrivateCrtKeySpec
```
open class RSAMultiPrimePrivateCrtKeySpec : RSAPrivateKeySpec
```
|---|---|--------------------------------------------------------------------------------------------------------------------------------------------------------|
| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) |||
| ↳ | [java.security.spec.RSAPrivateKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAPrivateKeySpec) ||
| | ↳ | [java.security.spec.RSAMultiPrimePrivateCrtKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#) |
This class specifies an RSA multi-prime private key, as defined in the[PKCS#1 v2.2](https://tools.ietf.org/rfc/rfc8017.txt)standard using the Chinese Remainder Theorem (CRT) information values for efficiency.
## Summary
| Public constructors ||
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| [RSAMultiPrimePrivateCrtKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#RSAMultiPrimePrivateCrtKeySpec(java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20kotlin.Array))`(`modulus:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `publicExponent:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `privateExponent:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeP:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeQ:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeExponentP:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeExponentQ:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `crtCoefficient:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `otherPrimeInfo:` `[Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)<[RSAOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAOtherPrimeInfo)!>!`)` Creates a new`RSAMultiPrimePrivateCrtKeySpec`. |
| [RSAMultiPrimePrivateCrtKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#RSAMultiPrimePrivateCrtKeySpec(java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20java.math.BigInteger,%20kotlin.Array,%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#)!`, `privateExponent:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeP:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeQ:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeExponentP:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `primeExponentQ:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `crtCoefficient:` `[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!`, `otherPrimeInfo:` `[Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)<[RSAOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAOtherPrimeInfo)!>!`, `keyParams:` `[AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)!`)` Creates a new`RSAMultiPrimePrivateCrtKeySpec`with additional key parameters. |
| Public methods ||
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getCrtCoefficient](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getCrtCoefficient())`()` Returns the crtCoefficient. |
| open[Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)\<[RSAOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAOtherPrimeInfo)!\>! | [getOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getOtherPrimeInfo())`()` Returns a copy of the otherPrimeInfo or null if there are only two prime factors (p and q). |
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getPrimeExponentP](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getPrimeExponentP())`()` Returns the primeExponentP. |
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getPrimeExponentQ](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getPrimeExponentQ())`()` Returns the primeExponentQ. |
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getPrimeP](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getPrimeP())`()` Returns the primeP. |
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getPrimeQ](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getPrimeQ())`()` Returns the primeQ. |
| open[BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getPublicExponent](https://developer.android.com/reference/kotlin/java/security/spec/RSAMultiPrimePrivateCrtKeySpec#getPublicExponent())`()` Returns the public exponent. |
| Inherited functions ||
|---|---|
| From class[RSAPrivateKeySpec](https://developer.android.com/reference/kotlin/java/security/spec/RSAPrivateKeySpec) |---------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getModulus](https://developer.android.com/reference/kotlin/java/security/spec/RSAPrivateKeySpec#getModulus())`()`
Returns the modulus.
| | [AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)! | [getParams](https://developer.android.com/reference/kotlin/java/security/spec/RSAPrivateKeySpec#getParams())`()`
Returns the parameters associated with this key, may be null if not present.
| | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | [getPrivateExponent](https://developer.android.com/reference/kotlin/java/security/spec/RSAPrivateKeySpec#getPrivateExponent())`()`
Returns the private exponent.
| ||
## Public constructors
### RSAMultiPrimePrivateCrtKeySpec
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
RSAMultiPrimePrivateCrtKeySpec(
modulus: BigInteger!,
publicExponent: BigInteger!,
privateExponent: BigInteger!,
primeP: BigInteger!,
primeQ: BigInteger!,
primeExponentP: BigInteger!,
primeExponentQ: BigInteger!,
crtCoefficient: BigInteger!,
otherPrimeInfo: Array!)
```
Creates a new`RSAMultiPrimePrivateCrtKeySpec`.
Note that the contents of`otherPrimeInfo`are copied to protect against subsequent modification when constructing this object.
| Parameters ||
|-------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `modulus` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the modulus n |
| `publicExponent` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the public exponent e |
| `privateExponent` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the private exponent d |
| `primeP` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the prime factor p of n |
| `primeQ` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the prime factor q of n |
| `primeExponentP` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:this is d mod (p-1) |
| `primeExponentQ` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:this is d mod (q-1) |
| `crtCoefficient` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the Chinese Remainder Theorem coefficient q-1 mod p |
| `otherPrimeInfo` | [Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)\<[RSAOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAOtherPrimeInfo)!\>!:triplets of the rest of primes, null can be specified if there are only two prime factors (p and q) |
| Exceptions ||
|--------------------------------------|---------------------------------------------------------------------------------|
| `java.lang.NullPointerException` | if any of the specified parameters with the exception of`otherPrimeInfo`is null |
| `java.lang.IllegalArgumentException` | if an empty, i.e. 0-length,`otherPrimeInfo`is specified |
### RSAMultiPrimePrivateCrtKeySpec
Added in[API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
RSAMultiPrimePrivateCrtKeySpec(
modulus: BigInteger!,
publicExponent: BigInteger!,
privateExponent: BigInteger!,
primeP: BigInteger!,
primeQ: BigInteger!,
primeExponentP: BigInteger!,
primeExponentQ: BigInteger!,
crtCoefficient: BigInteger!,
otherPrimeInfo: Array!,
keyParams: AlgorithmParameterSpec!)
```
Creates a new`RSAMultiPrimePrivateCrtKeySpec`with additional key parameters.
Note that the contents of`otherPrimeInfo`are copied to protect against subsequent modification when constructing this object.
| Parameters ||
|-------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `modulus` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the modulus n |
| `publicExponent` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the public exponent e |
| `privateExponent` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the private exponent d |
| `primeP` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the prime factor p of n |
| `primeQ` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the prime factor q of n |
| `primeExponentP` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:this is d mod (p-1) |
| `primeExponentQ` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:this is d mod (q-1) |
| `crtCoefficient` | [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)!:the Chinese Remainder Theorem coefficient q-1 mod p |
| `otherPrimeInfo` | [Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)\<[RSAOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAOtherPrimeInfo)!\>!:triplets of the rest of primes, null can be specified if there are only two prime factors (p and q) |
| `keyParams` | [AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec)!:the parameters associated with key |
| Exceptions ||
|--------------------------------------|-----------------------------------------------------------------------------------------------|
| `java.lang.NullPointerException` | if any of the specified parameters with the exception of`otherPrimeInfo`and`keyParams`is null |
| `java.lang.IllegalArgumentException` | if an empty, i.e. 0-length,`otherPrimeInfo`is specified |
## Public methods
### getCrtCoefficient
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getCrtCoefficient(): BigInteger!
```
Returns the crtCoefficient.
| Return ||
|------------------------------------------------------------------------------------------|---------------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the crtCoefficient. |
### getOtherPrimeInfo
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getOtherPrimeInfo(): Array!
```
Returns a copy of the otherPrimeInfo or null if there are only two prime factors (p and q).
| Return ||
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------|
| [Array](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-array/index.html)<[RSAOtherPrimeInfo](https://developer.android.com/reference/kotlin/java/security/spec/RSAOtherPrimeInfo)!>! | the otherPrimeInfo. Returns a new array each time this method is called. |
### getPrimeExponentP
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getPrimeExponentP(): BigInteger!
```
Returns the primeExponentP.
| Return ||
|------------------------------------------------------------------------------------------|---------------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the primeExponentP. |
### getPrimeExponentQ
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getPrimeExponentQ(): BigInteger!
```
Returns the primeExponentQ.
| Return ||
|------------------------------------------------------------------------------------------|---------------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the primeExponentQ. |
### getPrimeP
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getPrimeP(): BigInteger!
```
Returns the primeP.
| Return ||
|------------------------------------------------------------------------------------------|-------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the primeP. |
### getPrimeQ
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getPrimeQ(): BigInteger!
```
Returns the primeQ.
| Return ||
|------------------------------------------------------------------------------------------|-------------|
| [BigInteger](https://developer.android.com/reference/kotlin/java/math/BigInteger.html#)! | the primeQ. |
### 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. |