Initial RSA implementation.stabilize-7821.B

Includes support for encrypt / decrypt,
and sign / verify;  padding schemes OAEP /
PKCS1; supporting bignum library.

RSA key sizes must be a multiple of 32-bits
(with the top bit set).  Keying material,
input and output buffers are required to be
word-aligned.

BRANCH=none
TEST=added encrypt/decrypt sign/verify tests, compatibility with openssl tested
BUG=chrome-os-partner:43025,chrome-os-partner:47524
Change-Id: I6bc324c651e3178bb45bb75ab5935d9bc07efbce
Signed-off-by: nagendra modadugu <ngm@google.com>
Reviewed-on: https://chromium-review.googlesource.com/316942
Commit-Ready: Marius Schilder <mschilder@chromium.org>
Tested-by: Nagendra Modadugu <ngm@google.com>
Reviewed-by: Marius Schilder <mschilder@chromium.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/chip/g/dcrypto/dcrypto.h b/chip/g/dcrypto/dcrypto.h
index a39350fd13..3d8e78ab96 100644
--- a/chip/g/dcrypto/dcrypto.h
+++ b/chip/g/dcrypto/dcrypto.h
@@ -31,6 +31,11 @@ struct HASH_CTX;   /* Forward declaration. */
 typedef struct HASH_CTX SHA1_CTX;
 typedef struct HASH_CTX SHA256_CTX;
 
+enum hashing_mode {
+	HASH_SHA1 = 0,
+	HASH_SHA256 = 1
+};
+
 #define DCRYPTO_HASH_update(ctx, data, len) \
 	((ctx)->vtab->update((ctx), (data), (len)))
 #define DCRYPTO_HASH_final(ctx) \
@@ -72,4 +77,46 @@ const uint8_t *DCRYPTO_SHA1_hash(const uint8_t *data, uint32_t n,
 const uint8_t *DCRYPTO_SHA256_hash(const uint8_t *data, uint32_t n,
 				uint8_t *digest);
 
+/*
+ *  RSA.
+ */
+
+/* Largest supported key size, 2048-bits. */
+#define RSA_MAX_BYTES   256
+#define RSA_MAX_WORDS   (RSA_MAX_BYTES / sizeof(uint32_t))
+
+struct RSA {
+	uint32_t e;
+	struct BIGNUM N;
+	struct BIGNUM d;
+};
+
+enum padding_mode {
+	PADDING_MODE_PKCS1 = 0,
+	PADDING_MODE_OAEP  = 1
+};
+
+/* Calculate r = m ^ e mod N */
+int DCRYPTO_rsa_encrypt(struct RSA *rsa, uint8_t *out, uint32_t *out_len,
+			const uint8_t *in, const uint32_t in_len,
+			enum padding_mode padding, enum hashing_mode hashing,
+			const char *label);
+
+/* Calculate r = m ^ d mod N */
+int DCRYPTO_rsa_decrypt(struct RSA *rsa, uint8_t *out, uint32_t *out_len,
+			const uint8_t *in, const uint32_t in_len,
+			enum padding_mode padding, enum hashing_mode hashing,
+			const char *label);
+
+/* Calculate r = m ^ d mod N */
+int DCRYPTO_rsa_sign(struct RSA *rsa, uint8_t *out, uint32_t *out_len,
+		const uint8_t *in, const uint32_t in_len,
+		enum padding_mode padding, enum hashing_mode hashing);
+
+/* Calculate r = m ^ e mod N */
+int DCRYPTO_rsa_verify(struct RSA *rsa, const uint8_t *digest,
+		uint32_t digest_len, const uint8_t *sig,
+		const uint32_t sig_len,	enum padding_mode padding,
+		enum hashing_mode hashing);
+
 #endif  /* ! __EC_CHIP_G_DCRYPTO_DCRYPTO_H */