diff --git a/include/openssl/base.h b/include/openssl/base.h
index b74e66f..76955c7 100644
--- a/include/openssl/base.h
+++ b/include/openssl/base.h
@@ -389,6 +389,7 @@
 typedef struct conf_value_st CONF_VALUE;
 typedef struct crypto_buffer_pool_st CRYPTO_BUFFER_POOL;
 typedef struct crypto_buffer_st CRYPTO_BUFFER;
+typedef struct ctr_drbg_state_st CTR_DRBG_STATE;
 typedef struct dh_st DH;
 typedef struct dsa_st DSA;
 typedef struct ec_group_st EC_GROUP;
diff --git a/include/openssl/ctrdrbg.h b/include/openssl/ctrdrbg.h
new file mode 100644
index 0000000..62afe0c
--- /dev/null
+++ b/include/openssl/ctrdrbg.h
@@ -0,0 +1,76 @@
+/* Copyright (c) 2022, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_CTRDRBG_H
+#define OPENSSL_HEADER_CTRDRBG_H
+
+#include <openssl/base.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+// FIPS pseudo-random number generator.
+
+
+// CTR-DRBG state objects.
+//
+// CTR_DRBG_STATE contains the state of a FIPS AES-CTR-based pseudo-random
+// number generator. If BoringSSL was built in FIPS mode then this is a FIPS
+// Approved algorithm.
+
+// CTR_DRBG_ENTROPY_LEN is the number of bytes of input entropy. See SP
+// 800-90Ar1, table 3.
+#define CTR_DRBG_ENTROPY_LEN 48
+
+// CTR_DRBG_MAX_GENERATE_LENGTH is the maximum number of bytes that can be
+// generated in a single call to |CTR_DRBG_generate|.
+#define CTR_DRBG_MAX_GENERATE_LENGTH 65536
+
+// CTR_DRBG_new returns an initialized |CTR_DRBG_STATE|, or NULL if either
+// allocation failed or if |personalization_len| is invalid.
+OPENSSL_EXPORT CTR_DRBG_STATE *CTR_DRBG_new(
+    const uint8_t entropy[CTR_DRBG_ENTROPY_LEN], const uint8_t *personalization,
+    size_t personalization_len);
+
+// CTR_DRBG_free frees |state| if non-NULL, or else does nothing.
+OPENSSL_EXPORT void CTR_DRBG_free(CTR_DRBG_STATE* state);
+
+// CTR_DRBG_reseed reseeds |drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of entropy
+// in |entropy| and, optionally, up to |CTR_DRBG_ENTROPY_LEN| bytes of
+// additional data. It returns one on success or zero on error.
+OPENSSL_EXPORT int CTR_DRBG_reseed(CTR_DRBG_STATE *drbg,
+                                   const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
+                                   const uint8_t *additional_data,
+                                   size_t additional_data_len);
+
+// CTR_DRBG_generate processes to up |CTR_DRBG_ENTROPY_LEN| bytes of additional
+// data (if any) and then writes |out_len| random bytes to |out|, where
+// |out_len| <= |CTR_DRBG_MAX_GENERATE_LENGTH|. It returns one on success or
+// zero on error.
+OPENSSL_EXPORT int CTR_DRBG_generate(CTR_DRBG_STATE *drbg, uint8_t *out,
+                                     size_t out_len,
+                                     const uint8_t *additional_data,
+                                     size_t additional_data_len);
+
+// CTR_DRBG_clear zeroises the state of |drbg|.
+OPENSSL_EXPORT void CTR_DRBG_clear(CTR_DRBG_STATE *drbg);
+
+
+#if defined(__cplusplus)
+}  // extern C
+#endif
+
+#endif  // OPENSSL_HEADER_CTRDRBG_H