diff --git a/src/crypto/rsa.c b/src/crypto/rsa.c
index be055d881..c0a56acd3 100644
--- a/src/crypto/rsa.c
+++ b/src/crypto/rsa.c
@@ -70,6 +70,9 @@ struct rsa_context {
 	void *tmp;
 };
 
+/** Generate random data */
+int ( * rsa_get_random ) ( void *data, size_t len ) = get_random_nz;
+
 /**
  * Identify RSA prefix
  *
@@ -331,7 +334,7 @@ static int rsa_encrypt ( const struct asn1_cursor *key,
 	encoded = temp;
 	encoded[0] = 0x00;
 	encoded[1] = 0x02;
-	if ( ( rc = get_random_nz ( &encoded[2], random_nz_len ) ) != 0 ) {
+	if ( ( rc = rsa_get_random ( &encoded[2], random_nz_len ) ) != 0 ) {
 		DBGC ( &context, "RSA %p could not generate random data: %s\n",
 		       &context, strerror ( rc ) );
 		goto err_random;
@@ -339,6 +342,8 @@ static int rsa_encrypt ( const struct asn1_cursor *key,
 	encoded[ 2 + random_nz_len ] = 0x00;
 	memcpy ( &encoded[ context.max_len - plaintext->len ],
 		 plaintext->data, plaintext->len );
+	DBGC ( &context, "RSA %p encoded:\n", &context );
+	DBGC_HDA ( &context, 0, encoded, context.max_len );
 
 	/* Create space for ciphertext */
 	if ( ( rc = asn1_grow ( ciphertext, context.max_len ) ) != 0 )
@@ -404,6 +409,8 @@ static int rsa_decrypt ( const struct asn1_cursor *key,
 	temp = context.input0;
 	encoded = temp;
 	rsa_cipher ( &context, ciphertext->data, encoded );
+	DBGC ( &context, "RSA %p encoded:\n", &context );
+	DBGC_HDA ( &context, 0, encoded, context.max_len );
 
 	/* Parse the message */
 	end = ( encoded + context.max_len );
diff --git a/src/include/ipxe/rsa.h b/src/include/ipxe/rsa.h
index c5ae919ae..289743c40 100644
--- a/src/include/ipxe/rsa.h
+++ b/src/include/ipxe/rsa.h
@@ -58,4 +58,6 @@ struct rsa_digestinfo_prefix {
 
 extern struct pubkey_algorithm rsa_algorithm;
 
+extern int ( * rsa_get_random ) ( void *data, size_t len );
+
 #endif /* _IPXE_RSA_H */
diff --git a/src/tests/ecdsa_test.c b/src/tests/ecdsa_test.c
index 0ea039b1f..007ee12c1 100644
--- a/src/tests/ecdsa_test.c
+++ b/src/tests/ecdsa_test.c
@@ -67,6 +67,7 @@ PUBKEY_SIGN_TEST ( p256_hw_test, &ecdsa_algorithm,
 		 0x59, 0xd5, 0xdc, 0x3d, 0xb8, 0x13, 0x8f, 0x90, 0x26, 0xfc,
 		 0xf5, 0xce, 0xcb, 0xf9, 0x68, 0x91, 0x59, 0x87, 0xc6, 0x7d,
 		 0x2a ),
+	RANDOM(),
 	PLAINTEXT ( 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c,
 		    0x64, 0x0a ),
 	&sha256_algorithm,
@@ -104,6 +105,7 @@ PUBKEY_SIGN_TEST ( p256_hw_sha512_test, &ecdsa_algorithm,
 		 0x59, 0xd5, 0xdc, 0x3d, 0xb8, 0x13, 0x8f, 0x90, 0x26, 0xfc,
 		 0xf5, 0xce, 0xcb, 0xf9, 0x68, 0x91, 0x59, 0x87, 0xc6, 0x7d,
 		 0x2a ),
+	RANDOM(),
 	PLAINTEXT ( 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c,
 		    0x64, 0x0a ),
 	&sha512_algorithm,
@@ -142,6 +144,7 @@ PUBKEY_SIGN_TEST ( p256_random_test, &ecdsa_algorithm,
 		 0x59, 0xd5, 0xdc, 0x3d, 0xb8, 0x13, 0x8f, 0x90, 0x26, 0xfc,
 		 0xf5, 0xce, 0xcb, 0xf9, 0x68, 0x91, 0x59, 0x87, 0xc6, 0x7d,
 		 0x2a ),
+	RANDOM(),
 	PLAINTEXT ( 0xe0, 0xf0, 0x1b, 0xd1, 0x95, 0xe0, 0x4b, 0xd1, 0xf7, 0x4a,
 		    0x18, 0xca, 0x60, 0x02, 0x29, 0xc1, 0x58, 0x03, 0xf8, 0xc2,
 		    0x3c, 0x0f, 0x86, 0x55, 0xc5, 0x22, 0x88, 0x7e, 0x1f, 0x6c,
@@ -211,6 +214,7 @@ PUBKEY_SIGN_TEST ( p384_random_test, &ecdsa_algorithm,
 		 0x84, 0x01, 0x52, 0x28, 0xb8, 0x18, 0xb0, 0xcc, 0x33, 0x9c,
 		 0x44, 0x98, 0xa3, 0x59, 0x92, 0x36, 0xe3, 0x46, 0x72, 0xa8,
 		 0x86, 0xec, 0x69, 0x24, 0x29, 0x29, 0xc0, 0xca, 0x2b, 0x40 ),
+	RANDOM(),
 	PLAINTEXT ( 0xe0, 0xf0, 0x1b, 0xd1, 0x95, 0xe0, 0x4b, 0xd1, 0xf7, 0x4a,
 		    0x18, 0xca, 0x60, 0x02, 0x29, 0xc1, 0x58, 0x03, 0xf8, 0xc2,
 		    0x3c, 0x0f, 0x86, 0x55, 0xc5, 0x22, 0x88, 0x7e, 0x1f, 0x6c,
diff --git a/src/tests/pubkey_test.c b/src/tests/pubkey_test.c
index b94ed90ff..130af02f2 100644
--- a/src/tests/pubkey_test.c
+++ b/src/tests/pubkey_test.c
@@ -40,6 +40,34 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/test.h>
 #include "pubkey_test.h"
 
+/** Random data input */
+static const uint8_t *pubkey_random;
+
+/** Length of random data input */
+static size_t pubkey_random_len;
+
+/**
+ * Get random data input
+ *
+ * @v data		Output buffer
+ * @v len		Length of output buffer
+ * @ret rc		Return status code
+ */
+int pubkey_test_get_random ( void *data, size_t len ) {
+
+	/* Sanity check */
+	assert ( len <= pubkey_random_len );
+
+	/* Return random data */
+	memcpy ( data, pubkey_random, len );
+
+	/* Consume random data */
+	pubkey_random += len;
+	pubkey_random_len -= len;
+
+	return 0;
+}
+
 /**
  * Report public key encryption and decryption test result
  *
@@ -57,6 +85,18 @@ void pubkey_okx ( struct pubkey_test *test, const char *file,
 	okx ( pubkey_match ( pubkey, &test->private, &test->public ) == 0,
 	      file, line );
 
+	/* Test encrypting with public key to obtain known ciphertext */
+	ciphertext.data = NULL;
+	ciphertext.len = 0;
+	pubkey_random = test->random;
+	pubkey_random_len = test->random_len;
+	okx ( pubkey_encrypt ( pubkey, &test->public, &test->plaintext,
+			       &ciphertext ) == 0, file, line );
+	okx ( pubkey_random_len == 0, file, line );
+	okx ( asn1_compare ( asn1_built ( &ciphertext ),
+			     &test->ciphertext ) == 0, file, line );
+	free ( ciphertext.data );
+
 	/* Test decrypting with private key to obtain known plaintext */
 	plaintext.data = NULL;
 	plaintext.len = 0;
@@ -71,8 +111,11 @@ void pubkey_okx ( struct pubkey_test *test, const char *file,
 	ciphertext.len = 0;
 	plaintext.data = NULL;
 	plaintext.len = 0;
+	pubkey_random = test->random;
+	pubkey_random_len = test->random_len;
 	okx ( pubkey_encrypt ( pubkey, &test->private, &test->plaintext,
 			       &ciphertext ) == 0, file, line );
+	okx ( pubkey_random_len == 0, file, line );
 	okx ( pubkey_decrypt ( pubkey, &test->public,
 			       asn1_built ( &ciphertext ),
 			       &plaintext ) == 0, file, line );
@@ -86,8 +129,11 @@ void pubkey_okx ( struct pubkey_test *test, const char *file,
 	ciphertext.len = 0;
 	plaintext.data = NULL;
 	plaintext.len = 0;
+	pubkey_random = test->random;
+	pubkey_random_len = test->random_len;
 	okx ( pubkey_encrypt ( pubkey, &test->public, &test->plaintext,
 			       &ciphertext ) == 0, file, line );
+	okx ( pubkey_random_len == 0, file, line );
 	okx ( pubkey_decrypt ( pubkey, &test->private,
 			       asn1_built ( &ciphertext ),
 			       &plaintext ) == 0, file, line );
@@ -140,8 +186,11 @@ void pubkey_sign_okx ( struct pubkey_sign_test *test, const char *file,
 			      &cursor ) == 0, file, line );
 
 	/* Test signing using private key */
+	pubkey_random = test->random;
+	pubkey_random_len = test->random_len;
 	okx ( pubkey_sign ( pubkey, &test->private, digest, digestout,
 			    &builder ) == 0, file, line );
+	okx ( pubkey_random_len == 0, file, line );
 	okx ( builder.len != 0, file, line );
 	okx ( asn1_compare ( asn1_built ( &builder ), &test->signature ) == 0,
 	      file, line );
diff --git a/src/tests/pubkey_test.h b/src/tests/pubkey_test.h
index 33b301a6e..f6c952d3f 100644
--- a/src/tests/pubkey_test.h
+++ b/src/tests/pubkey_test.h
@@ -15,14 +15,13 @@ struct pubkey_test {
 	const struct asn1_cursor private;
 	/** Public key */
 	const struct asn1_cursor public;
+	/** Random data input */
+	const void *random;
+	/** Random data input length */
+	size_t random_len;
 	/** Plaintext */
 	const struct asn1_cursor plaintext;
-	/** Ciphertext
-	 *
-	 * Note that the encryption process may include some random
-	 * padding, so a given plaintext will encrypt to multiple
-	 * different ciphertexts.
-	 */
+	/** Ciphertext */
 	const struct asn1_cursor ciphertext;
 };
 
@@ -34,6 +33,10 @@ struct pubkey_sign_test {
 	const struct asn1_cursor private;
 	/** Public key */
 	const struct asn1_cursor public;
+	/** Random data input */
+	const void *random;
+	/** Random data input length */
+	size_t random_len;
 	/** Plaintext */
 	const void *plaintext;
 	/** Plaintext length */
@@ -50,6 +53,9 @@ struct pubkey_sign_test {
 /** Define inline public key data */
 #define PUBLIC(...) { __VA_ARGS__ }
 
+/** Define inline random data */
+#define RANDOM(...) { __VA_ARGS__ }
+
 /** Define inline plaintext data */
 #define PLAINTEXT(...) { __VA_ARGS__ }
 
@@ -66,14 +72,16 @@ struct pubkey_sign_test {
  * @v PUBKEY		Public-key algorithm
  * @v PRIVATE		Private key
  * @v PUBLIC		Public key
+ * @v RANDOM		Random data
  * @v PLAINTEXT		Plaintext
  * @v CIPHERTEXT	Ciphertext
  * @ret test		Encryption and decryption test
  */
-#define PUBKEY_TEST( name, PUBKEY, PRIVATE, PUBLIC, PLAINTEXT,		\
-			   CIPHERTEXT )					\
+#define PUBKEY_TEST( name, PUBKEY, PRIVATE, PUBLIC, RANDOM, PLAINTEXT,	\
+		     CIPHERTEXT )					\
 	static const uint8_t name ## _private[] = PRIVATE;		\
 	static const uint8_t name ## _public[] = PUBLIC;		\
+	static const uint8_t name ## _random[] = RANDOM;		\
 	static const uint8_t name ## _plaintext[] = PLAINTEXT;		\
 	static const uint8_t name ## _ciphertext[] = CIPHERTEXT;	\
 	static struct pubkey_test name = {				\
@@ -86,6 +94,8 @@ struct pubkey_sign_test {
 			.data = name ## _public,			\
 			.len = sizeof ( name ## _public ),		\
 		},							\
+		.random = name ## _random,				\
+		.random_len = sizeof ( name ## _random ),		\
 		.plaintext = {						\
 			.data = name ## _plaintext,			\
 			.len = sizeof ( name ## _plaintext ),		\
@@ -103,15 +113,17 @@ struct pubkey_sign_test {
  * @v PUBKEY		Public-key algorithm
  * @v PRIVATE		Private key
  * @v PUBLIC		Public key
+ * @v RANDOM		Random data
  * @v PLAINTEXT		Plaintext
  * @v DIGEST		Digest algorithm
  * @v SIGNATURE		Signature
  * @ret test		Signature test
  */
-#define PUBKEY_SIGN_TEST( name, PUBKEY, PRIVATE, PUBLIC, PLAINTEXT,	\
-			  DIGEST, SIGNATURE )				\
+#define PUBKEY_SIGN_TEST( name, PUBKEY, PRIVATE, PUBLIC, RANDOM,	\
+			  PLAINTEXT, DIGEST, SIGNATURE )		\
 	static const uint8_t name ## _private[] = PRIVATE;		\
 	static const uint8_t name ## _public[] = PUBLIC;		\
+	static const uint8_t name ## _random[] = RANDOM;		\
 	static const uint8_t name ## _plaintext[] = PLAINTEXT;		\
 	static const uint8_t name ## _signature[] = SIGNATURE;		\
 	static struct pubkey_sign_test name = {				\
@@ -124,6 +136,8 @@ struct pubkey_sign_test {
 			.data = name ## _public,			\
 			.len = sizeof ( name ## _public ),		\
 		},							\
+		.random = name ## _random,				\
+		.random_len = sizeof ( name ## _random ),		\
 		.plaintext = name ## _plaintext,			\
 		.plaintext_len = sizeof ( name ## _plaintext ),		\
 		.digest = DIGEST,					\
@@ -133,6 +147,7 @@ struct pubkey_sign_test {
 		},							\
 	}
 
+extern int pubkey_test_get_random ( void *data, size_t len );
 extern void pubkey_okx ( struct pubkey_test *test,
 			 const char *file, unsigned int line );
 extern void pubkey_sign_okx ( struct pubkey_sign_test *test,
diff --git a/src/tests/rsa_test.c b/src/tests/rsa_test.c
index 13160934a..871c8461f 100644
--- a/src/tests/rsa_test.c
+++ b/src/tests/rsa_test.c
@@ -87,6 +87,11 @@ PUBKEY_TEST ( hw_test, &rsa_algorithm,
 		 0x04, 0xf2, 0x82, 0xc4, 0x7b, 0x6a, 0x3e, 0xec, 0x53, 0x7a,
 		 0xe3, 0x4e, 0xa8, 0xc9, 0xf9, 0x1f, 0x2a, 0x13, 0x0d, 0x02,
 		 0x03, 0x01, 0x00, 0x01 ),
+	RANDOM ( 0x87, 0x90, 0xdf, 0x03, 0x31, 0x20, 0x31, 0x63, 0x86, 0x30,
+		 0xb9, 0xb1, 0x99, 0x5e, 0xf8, 0x2b, 0xb7, 0x6b, 0x62, 0x56,
+		 0x8c, 0x2b, 0x88, 0xa1, 0x5b, 0x1e, 0x37, 0xaa, 0x12, 0xa6,
+		 0xf6, 0xe8, 0x3a, 0x41, 0x91, 0x70, 0x24, 0x3f, 0x89, 0x9b,
+		 0x6e, 0x81, 0x63, 0x8c, 0xe1, 0x63, 0x93, 0x19, 0x49 ),
 	PLAINTEXT ( 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c,
 		    0x64, 0x0a ),
 	CIPHERTEXT ( 0x39, 0xff, 0x5c, 0x54, 0x65, 0x3e, 0x6a, 0xab, 0xc0, 0x62,
@@ -144,6 +149,11 @@ PUBKEY_TEST ( hw_test_pkcs8, &rsa_algorithm,
 		 0x04, 0xf2, 0x82, 0xc4, 0x7b, 0x6a, 0x3e, 0xec, 0x53, 0x7a,
 		 0xe3, 0x4e, 0xa8, 0xc9, 0xf9, 0x1f, 0x2a, 0x13, 0x0d, 0x02,
 		 0x03, 0x01, 0x00, 0x01 ),
+	RANDOM ( 0x87, 0x90, 0xdf, 0x03, 0x31, 0x20, 0x31, 0x63, 0x86, 0x30,
+		 0xb9, 0xb1, 0x99, 0x5e, 0xf8, 0x2b, 0xb7, 0x6b, 0x62, 0x56,
+		 0x8c, 0x2b, 0x88, 0xa1, 0x5b, 0x1e, 0x37, 0xaa, 0x12, 0xa6,
+		 0xf6, 0xe8, 0x3a, 0x41, 0x91, 0x70, 0x24, 0x3f, 0x89, 0x9b,
+		 0x6e, 0x81, 0x63, 0x8c, 0xe1, 0x63, 0x93, 0x19, 0x49 ),
 	PLAINTEXT ( 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c,
 		    0x64, 0x0a ),
 	CIPHERTEXT ( 0x39, 0xff, 0x5c, 0x54, 0x65, 0x3e, 0x6a, 0xab, 0xc0, 0x62,
@@ -198,6 +208,7 @@ PUBKEY_SIGN_TEST ( md5_test, &rsa_algorithm,
 		 0xf5, 0xb0, 0x63, 0xa0, 0x84, 0xc0, 0xaf, 0x4e, 0xbe, 0x6a,
 		 0xd3, 0x84, 0x3f, 0xec, 0x42, 0x17, 0xe9, 0x25, 0xe1, 0x02,
 		 0x03, 0x01, 0x00, 0x01 ),
+	RANDOM(),
 	PLAINTEXT ( 0x9d, 0x5b, 0x46, 0x42, 0x27, 0xc0, 0xf1, 0x4b, 0xe5, 0x9e,
 		    0xd3, 0x10, 0xa1, 0xeb, 0x16, 0xc3, 0xc6, 0x8f, 0x1a, 0x18,
 		    0x86, 0xc3, 0x92, 0x15, 0x2d, 0x65, 0xa0, 0x40, 0xe1, 0x3e,
@@ -271,6 +282,7 @@ PUBKEY_SIGN_TEST ( sha1_test, &rsa_algorithm,
 		 0x24, 0x81, 0x4b, 0x4d, 0x48, 0x5a, 0xd2, 0x29, 0x14, 0xeb,
 		 0x38, 0xdd, 0x3e, 0xb5, 0x57, 0x45, 0x9b, 0xed, 0x33, 0x02,
 		 0x03, 0x01, 0x00, 0x01 ),
+	RANDOM(),
 	PLAINTEXT ( 0xf7, 0x42, 0x01, 0x57, 0x6b, 0x70, 0xcc, 0x4a, 0xdc, 0xed,
 		    0x12, 0x83, 0x3f, 0xef, 0x27, 0xc1, 0x3c, 0x85, 0xdd, 0x5e,
 		    0x0a, 0x34, 0x98, 0xf9, 0x21, 0xd3, 0x24, 0x2a, 0x5a, 0xb2,
@@ -344,6 +356,7 @@ PUBKEY_SIGN_TEST ( sha256_test, &rsa_algorithm,
 		 0x35, 0x88, 0x3f, 0xde, 0xa2, 0xce, 0x46, 0x94, 0x30, 0xa9,
 		 0x76, 0xee, 0x25, 0xc5, 0x5d, 0xa6, 0xa6, 0x3a, 0xa5, 0x02,
 		 0x03, 0x01, 0x00, 0x01 ),
+	RANDOM(),
 	PLAINTEXT ( 0x60, 0xe7, 0xba, 0x9d, 0x5a, 0xe3, 0x2d, 0xfa, 0x5f, 0x47,
 		    0xdb, 0x93, 0x24, 0x2c, 0xc4, 0xe2, 0x61, 0xf3, 0x89, 0x4d,
 		    0x67, 0xad, 0xc8, 0xae, 0xf8, 0xe2, 0xfb, 0x52, 0x0f, 0x8d,
@@ -378,12 +391,21 @@ PUBKEY_SIGN_TEST ( sha256_test, &rsa_algorithm,
  *
  */
 static void rsa_test_exec ( void ) {
+	int ( * saved_get_random ) ( void *data, size_t len );
 
+	/* Temporarily override rsa_get_random() */
+	saved_get_random = rsa_get_random;
+	rsa_get_random = pubkey_test_get_random;
+
+	/* Run tests */
 	pubkey_ok ( &hw_test );
 	pubkey_ok ( &hw_test_pkcs8 );
 	pubkey_sign_ok ( &md5_test );
 	pubkey_sign_ok ( &sha1_test );
 	pubkey_sign_ok ( &sha256_test );
+
+	/* Restore rsa_get_random() */
+	rsa_get_random = saved_get_random;
 }
 
 /** RSA self-test */